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The discovery of the first artificial plastic in 1869, initially known as celluloid and invented by John Hyatt, aimed to replace ivory in ornaments and artistry, reducing the demand for elephant tusks. Hyatt's breakthrough involved dissolving camphor in nitrocellulose and alcohol under heat. While celebrated as a pioneering scientific achievement, little attention was paid to the long-term consequences of plastic proliferation. Today, the widespread use of plastics poses severe threats to marine and terrestrial ecosystems, including habitat competition, water contamination, and the release of environmental toxins, leading to widespread pollution. Developing countries, such as Nigeria, face disproportionate impacts due to the global surge in plastic production and consumption, which outpaces efforts in degradation and recycling. This article reviews the environmental effects of biodegradable (BPs) and non-biodegradable plastics (NBPs), focusing on disposal challenges and management strategies in such regions. It explores microbial degradation as a sustainable solution, synthesizing data from academic databases (PubMed, Scopus, Web of Science) spanning 2000 to 2023. Studies were screened based on relevance to plastic production, usage, disposal methods, and environmental outcomes, particularly in developing countries. The findings highlight that while developed nations manage plastic waste effectively through stringent regulations and innovative recycling, developing countries struggle with inefficient disposal methods, like landfilling and incineration, which contribute to soil and water contamination and greenhouse gas emissions. Microbial degradation is a promising, cost-effective approach to naturally breaking down plastics. The study advocates for enhanced research into microbial degradation and adopting bioremediation technologies globally, emphasizing knowledge sharing and best practices transfer from developed to developing nations. This review underscores the urgency of addressing plastic pollution through sustainable waste management practices, particularly in regions facing significant environmental and health challenges. Prioritizing microbial degradation aligns with environmental sustainability goals and offers a pragmatic solution for tackling plastic waste worldwide [ABSTRACT FROM AUTHOR]

To date, enumerable fungi have been reported to participate in the biodegradation of several notorious plastic materials following their isolation from soil of plastic-dumping sites, marine water, waste of mulch films, landfills, plant parts and gut of wax moth. The general mechanism begins with formation of hydrophobin and biofilm proceding to secretion of specific plastic degarding enzymes (peroxidase, hydrolase, protease and urease), penetration of three dimensional substrates and mineralization of plastic polymers into harmless products. As a result, several synthetic polymers including polyethylene, polystyrene, polypropylene, polyvinyl chloride, polyurethane and/or bio-degradable plastics have been validated to deteriorate within months through the action of a wide variety of fungal strains predominantly Ascomycota (Alternaria, Aspergillus, Cladosporium, Fusarium, Penicillium spp.). Understanding the potential and mode of operation of these organisms is thus of prime importance inspiring us to furnish an up to date view on all the presently known fungal strains claimed to mitigate the plastic waste problem. Future research henceforth needs to be directed towards metagenomic approach to distinguish polymer degrading microbial diversity followed by bio-augmentation to build fascinating future of waste disposal. [ABSTRACT FROM AUTHOR]

Citrus waste has been used as a source of bioplastics for research in different ways. Because the juice industry produces significant amounts of residue each year, it would be advantageous to use the byproducts in the creation of new materials. Researchers have long explored eco-friendly methods to convert citrus and other organic waste into polymers for producing biodegradable films. The goal of this study is to create biofilms from orange waste (OW) and ginger waste (GW) using an ultrafine grinder and study the films' properties. Since pectin has the ability to gel, and because cellulosic fibers are strong, citrus waste has been studied for its potential to produce biofilms. After being washed, dried, and milled, orange and ginger waste was shaped into films using a casting process. Tensile testing was used to determine the mechanical properties of biofilms, while dynamic mechanical thermal analysis (DMTA), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) were used to determine their thermal properties. As the number of grinding cycles increased, the suspension's viscosity increased from 29 mPa.s to 57 mPa.s for OW and from 217 mPa.s to 376 mPa.s for GW, while the particle size in the suspension significantly decreased. For OW and GW films, the highest tensile strength was 17 MPa and 15 MPa, respectively. The maximum strain obtained among all films was 4.8%. All the tested films were stable up to 150 °C, and maximum degradation occured after 300 °C. [ABSTRACT FROM AUTHOR]

Microplastics contribute to various environmental issues and serve as carriers for a wide range of toxic compounds such as pesticides, pharmaceuticals, and metal ions. Consequently, there is a gradual shift towards replacing them with biodegradable plastics (bioplastics). However, biodegradable plastics require specific conditions for complete biodegradation, and their biodeterioration often leads to the rapid production of smaller fragments, known as microbioplastics. In this review, we summarize selected issues related to the impact of plastic particles on soil properties and the soil microbiome. Findings from numerous studies indicate that both microplastics and microbioplastics induce adverse changes in soil microbiology, potentially increasing the abundance of soil-borne pathogens. Based on these observations, we argue that plastic particles could serve as carriers for colonies of soil-borne pathogens. Furthermore, the use of bioplastics may exacerbate this issue due to their easier and faster formation, increased support for biofilms, and more pronounced adverse effects on soil biota. However, further research is necessary to either substantiate or refute this perspective. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive review on microplastic from source to sink and reviews the current state of knowledge of the topic by focusing on the articles published within the last five years on identification, quantification, analyses, and effects of microplastics on soil and aqueous environments. Microplastics are materials formed either by the degradation of the plastic into smaller micro sized particles or obtained directly in daily products such as cosmetics, toothpastes, domestic cleaning products, etc. Hence, the origin of microplastics is either a primary or secondary microplastic source. The lack of information and research conducted on microplastics in soil compared to water influenced many disparities. These include variations in defining microplastics to lack of conclusive methodologies in analysis of microplastics in soil which therefore lead to gaps in identification of plastic source and comprehension of plastic pollution in soil. The effect of microplastics on different aquatic vertebrates, mammals, and humans is studied and, in most cases, various negative effects were observed in the organism's physiology. In addition to innovative control methods, there is a growing focus on exploring bioplastics as a potential substitute for traditional plastics. Numerous studies suggest that the environmental impact is more manageable with the production and use of bioplastics. Nonetheless, additional research is needed to confirm the viability of bioplastics as a potential solution. [ABSTRACT FROM AUTHOR]

Microplastic pollution is a pervasive global issue affecting various ecosystems. Despite the escalating production and well-documented contamination in both aquatic and terrestrial environments, the research focused on airborne microplastics and their interaction with terrestrial birds remains limited. In this study, we collected fecal sacs from Common swifts (Apus apus) to investigate their diet and to evaluate the potential ingestion of microplastics by both adults and nestlings. The diet was mainly composed of Hymenoptera and Coleoptera and did not differ among sexes and age classes. The 33% of nestlings' and 52% of adults' fecal sacs contained anthropogenic items, the totality of which was in the shape form of fibers. The 19.4% of the anthropogenic items were chemically characterized as microplastics, either polyethylene terephthalate (PET; two microfibers) or cellophane (four microfibers). Airborne anthropogenic items, including microplastic, might be passively ingested during the Common swift aerial feeding. In addition, our findings suggest that these ingested microparticles have the potential to be transferred to the offspring through food. While further research is essential to elucidate the pathways of microplastic ingestion, our results reinforce the evidence of the transfer of anthropogenic items from the atmosphere to the biota. [ABSTRACT FROM AUTHOR]

Polyvinyl chloride microplastics (PVC-MPs) are microplastic pollutants widely present in the environment, but their potential risks to human lung health and underlying toxicity mechanisms remain unknown. In this study, we systematically analyzed the effects of PVC-MPs on the transcriptome and metabolome of BEAS-2B cells using high-throughput RNA sequencing and untargeted metabolomics technologies. The results showed that exposure to PVC-MPs significantly reduced the viability of BEAS-2B cells, leading to the differential expression of 530 genes and 3768 metabolites. Further bioinformatics analyses showed that PVC-MP exposure influenced the expression of genes associated with fluid shear stress, the MAPK and TGF-β signaling pathways, and the levels of metabolites associated with amino acid metabolism. In particular, integrated pathway analysis showed that lipid metabolic pathways (including glycerophospholipid metabolism, glycerolipid metabolism, and sphingolipid metabolism) were significantly perturbed in BEAS-2B cells following PVC-MPs exposure. This study provides new insights and targets for a deeper understanding of the toxicity mechanism of PVC-MPs and for the prevention and treatment of PVC-MP-associated lung diseases. [ABSTRACT FROM AUTHOR]

This research highlights the importance of addressing bioplastic contamination in recycling processes to ensure the quality of recycled material and move towards a more sustainable circular economy. Polyethylene (PE) is a conventional plastic commonly used in packaging for which large amounts of waste are produced; therefore, PE is generally recycled and has an established recycling process. However, the contamination of biodegradable polymers in the PE waste stream could impact recycling. This study, therefore, focuses on polyethylene (PE) that has been polluted with a commercial thermoplastic starch polymer (TPS), as both materials are used to produce plastic films and bags, so cross-contamination is very likely to occur in waste separation. To achieve this, recycled PE was blended with small quantities of the commercial TPS and processed through melt extrusion and injection molding, and it was further characterized. The results indicate that the PE-TPS blend lacks miscibility, evidenced by deteriorated microstructure and mechanical properties. In addition, the presence of the commercial TPS affects the thermal stability, oxidation, and color of the recycled PE. [ABSTRACT FROM AUTHOR]

The excessive global demand for plastic materials has resulted in severe plastic waste pollution. Conventional plastics derived from non-renewable fossil fuels are non-biodegradable, leading to significant environmental problems. Algal-based bioplastics represent a more viable, renewable, and sustainable alternative to conventional plastics. They have identical properties and characteristics as conventional plastics while being naturally biodegradable. The potential of the algal biomass value chain has already been well-established by researchers. Here, we review the novel insights on research, technology, and commercialization trends of algal-based bioplastics, encompassing macroalgae and green microalgae/cyanobacteria. Data showed that within the last decade, there has been substantial interest in utilizing microalgae for biopolymer production, with more focus on using cyanobacterial species compared to green algae. Moreover, most of the research conducted has largely focused on the production of PHA or its co-polymers. Since 2011, there have been a total of 55 patents published related to algal-based bioplastics production. To date, ~ 81 entities worldwide (commercial and private businesses) produce bioplastics from algae. Overall results of this study emphasized that even with the economic and social challenges, algae possess a substantial potential for the sustainable development of bioplastics while also addressing the UN's SDGs. [ABSTRACT FROM AUTHOR]

The research on bioplastics (both biobased and biodegradable) is steadily growing and discovering environmentally friendly substitutes for conventional plastic. This review highlights the significance of bioplastics, analyzing, for the first time, the state of the art concerning the use of agri-food waste as an alternative substrate for biopolymer generation using Haloferax mediterranei. H. mediterranei is a highly researched strain able to produce polyhydroxybutyrate (PHB) since it can grow and produce bioplastic in high-salinity environments without requiring sterilization. Extensive research has been conducted on the genes and pathways responsible for PHB production using H. mediterranei to find out how fermentation parameters can be regulated to enhance cell growth and increase PHB accumulation. This review focuses on the current advancements in utilizing food waste as a substitute for costly substrates to reduce feedstock expenses. Specifically, it examines the production of biomass and the recovery of PHB from agri-food waste. Furthermore, it emphasizes the characterization of PHB and the significance of hydroxyvalerate (HV) abundance in the formation of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) copolymer. The downstream processing options are described, and the crucial factors associated with industrial scale-up are assessed, including substrates, bioreactors, process parameters, and bioplastic extraction and purification. Additionally, the economic implications of various options are discussed. [ABSTRACT FROM AUTHOR]

This research work is focused on the production of liquid hydrocarbon fuel from plastic waste. To perform the experiments, polypropylene waste (PPW) and polyethylene terephthalate (PETW) were selected and pyrolyzed in a semi‐batch reactor at a temperature of 500°C. Nearly 72.28 wt.% of liquid fuel was recovered from 100 g of plastic waste feed through non‐catalytic pyrolysis process. The application of catalyst GO‐Szr to the pyrolysis process increased the oil yield to 92.76 wt.%. The oil properties were studied, to assess the characteristics and to compare with that of diesel fuel. The properties of oil were found to possess very good diesel properties such as kinematic viscosity of 2.18 mm2/s, density of 790 kg/m3, cloud and pour point less than −11°C, Sulphur content less than 3 ppm and cetane number was found to be as high as 72.44. From these studies, it is highlighted that waste plastics pyrolysis is a suitable option to produce diesel‐like fuel. [ABSTRACT FROM AUTHOR]

The present chapter focuses on the recyclability of both renewable and biodegradable plastics, considering the recovery of matter (mechanical or chemical recycling) from the polymeric materials currently most diffused on the market. Biobased and compostable plastics are carbon neutral; thus, they do not contribute significantly to greenhouse gas (GHG) emissions. Nevertheless, recycling can be beneficial because it allows a prolongation of the material life cycle so that carbon is stored for a longer time up to the final composting. The chemical or mechanical recycling option is linked both to the possibility of reprocessing bioplastics without detrimental loss of properties as well as to the capability of selecting homogenous fractions of bioplastics after waste collection. Moreover, the different structural features of biodegradable bioplastics have resulted in different chemical recycling opportunities and also in different behaviors during the reprocessing operations necessary for recycling. All these aspects are discussed systematically in this review, considering biodegradable bioplastics, their blends and composites with natural fibers. [ABSTRACT FROM AUTHOR]

Rationale: Plastic mulch film manages weed growth and moisture loss on the surface of cropping beds. The chemical components of such plastics include polymer(s), additives and non‐intentionally added substances (NIASs). The unknown chemical nature and behaviours of these constituents require investigation due to their potential to add to the anthropogenic chemical burden in the agrifood system. Methods: Solvent extracts of a commercial 15% polylactic acid (PLA)/85% poly(butylene adipate‐co‐terephthalate) mulch film were investigated using gas chromatography–mass spectrometry (GC–MS) with electron ionisation to characterise the additive and NIAS components. The obscurity of some of the NIASs meant their identification was not readily achieved through routine MS library comparisons. As such, the identification of several polymer‐derived compounds required interpretation of the MS data and re‐application of the derived fragmentation patterns with reference to the wider literature. Unknowns were confirmed using commercially available compounds. Results: Unknown NIASs were identified as cyclic oligoesters comprised of the monomeric building blocks of the polymer system. Cyclic structures derived from the monomers of polybutylene adipate (PBA) and polybutylene terephthalate (PBT) fragmented through a primary pathway involving 1,5‐ and 1,3‐H transfers at ester linkages. Characteristic ions at m/z 111, 129, 183 and 201 for PBA‐derived cyclic oligoesters and m/z 104, 132, 149 and 221 for PBT‐derived cyclic oligoesters were assigned in the mass spectra of unknowns. Cyclic oligoesters containing sebacate moieties were also identified, indicating the presence of polybutylene sebacate as an unexpected component of the mulch. Conclusions: Systematic analyses of the sort reported here are valuable for providing alternative approaches for the identification of plastic‐related chemicals. Open publication of MS spectral data is required to build a greater understanding of the mulch film chemical components contributing to the environmental chemical load introduced to agroecosystems. [ABSTRACT FROM AUTHOR]

Low-cost detection systems are needed for the identification of microplastics (MPs) in environmental samples. However, their rapid identification is hindered by the need for complex isolation and pre-treatment methods. This study describes a comprehensive sensing platform to identify MPs in environmental samples without requiring independent separation or pre-treatment protocols. It leverages the physicochemical properties of macroporous-mesoporous silver (Ag) substrates templated with self-assembled polymeric micelles to concurrently separate and analyze multiple MP targets using surface-enhanced Raman spectroscopy (SERS). The hydrophobic layer on Ag aids in stabilizing the nanostructures in the environment and mitigates biofouling. To monitor complex samples with multiple MPs and to demultiplex numerous overlapping patterns, we develop a neural network (NN) algorithm called SpecATNet that employs a self-attention mechanism to resolve the complex dependencies and patterns in SERS data to identify six common types of MPs: polystyrene, polyethylene, polymethylmethacrylate, polytetrafluoroethylene, nylon, and polyethylene terephthalate. SpecATNet uses multi-label classification to analyze multi-component mixtures even in the presence of various interference agents. The combination of macroporous-mesoporous Ag substrates and self-attention-based NN technology holds potential to enable field monitoring of MPs by generating rich datasets that machines can interpret and analyze. Detection and identification of microplastics (MPs) in environmental samples is hampered by the need for isolation and pretreatment methods. Here, the authors combine porous Ag substrates with self-attention neural networks to directly identify six types of MPs in environmental samples. [ABSTRACT FROM AUTHOR]

The advancement of sustainable packaging technologies is crucial for environmental conservation and enhancing food shelf life. We advance sustainable packaging by developing cassava starch sheets functionalized with silver nanoparticles (AgNPs) via plasma-deposited 2-methyl-2-oxazoline thin film. This innovative method requires less precursors and generates no liquid waste, presenting a significant leap in eco-friendly packaging solutions. Uniquely, it deviates from traditional nanoparticle incorporation methods by emphasising surface functionalization over bulk integration, leveraging plasma polymerization for environmentally friendly and efficient AgNP immobilisation. This surface-centric approach offers distinct advantages in active packaging by enhancing the initial antimicrobial interaction at the packaging's surface. Surface morphology, characterised by SEM–EDX, and chemical composition, verified by XPS, indicated successful AgNP immobilisation after 5 and 25 h, albeit with some aggregation at prolonged immobilisation time. UV–Vis spectroscopy results confirmed the successful immobilisation of AgNPs and suggested enhanced light barrier properties of the treated sheets. AFM measurements revealed alterations in surface roughness post-treatment, correlating with changes in hydrophilicity and potentially impacting the moisture barrier properties of the packaging. The treated bioplastics showed improved mechanical properties, indicated by tensile strength and elongation at break. Antimicrobial testing revealed substantial efficacy against Gram-positive and Gram-negative bacteria, but not against fungi. All bioplastic samples demonstrated non-toxicity to fibroblast cells, irrespective of the treatments applied. This work paves the way for future developments targeted at improving the efficacy and scalability of plasma-nanoengineered bioplastics. [ABSTRACT FROM AUTHOR]

Background: Polystyrene microplastics (PS-MPs) exhibit multi-target, multidimensional, chronic, and low toxicity to the cardiovascular system. They enter the bloodstream through the gastrointestinal tract and respiratory system, altering blood parameters and conditions, inducing thrombotic diseases, and damaging myocardial tissue through the promotion of oxidative stress and inflammatory responses in myocardial cells. However, many of the links and mechanisms remain unclear. Methods: In this study, 48 wistar rats were randomly divided into four groups and exposed to different concentrations of PS-MPs: control group (0 mg/kg/d), low dose group (0.5 mg/kg/d), middle dose group (5 mg/kg/d) and high dose group (50 mg/kg/d), with 12 rats in each group. After 90 consecutive days of intragastric administration of PS-MPs, biochemical markers in myocardium, aorta and blood were detected, and HE staining was performed to observe the toxic effects of PSmps on cardiovascular system. Furthermore, non-targeted metabolomics methods were used to analyze the effect of PS-MPs exposure on the metabolism of cardiovascular system in rats, and to explore its potential molecular mechanism. Results: The results revealed no pathological changes in the heart and aorta following PS-MPs exposure. However, the myocardial enzyme levels in the high dose PS-MPs group of rats showed a significant increase. Moreover, exposure to polystyrene microplastics caused a disorder in lipid metabolism in rats, and led to an increase in indicators of inflammation and oxidative stress in myocardial and aortic tissues, but resulted in a decrease in the level of IL-6. Untargeted metabolomics results showed that metabolites with antioxidant and antiinflammatory effects, including equol and 4-hydroxybenzoic acid, were significantly upregulated. Conclusion: These results suggest that long-term exposure to high concentrations of PS-MPs may lead to abnormal lipid metabolism and cardiovascular system damage. The mechanism may be related to oxidative stress and inflammatory response. Exogenous antioxidants and changes in own metabolites may have a protective effect on the injury. Therefore, understanding the toxicological mechanism of PS-MPs not only helps to elucidate its pathogenesis, but also provides new ideas for the treatment of chronic diseases. [ABSTRACT FROM AUTHOR]

Detecting, separating, and characterizing airborne microplastics from other airborne particulates is currently challenging due to the various instrumental constraints and related sample preparation hurdles that must be overcome. The ability to measure these real-world environments is needed to better assess the risks associated with microplastics. To that end, the current study focused on developing a methodology for sampling and characterizing airborne microplastics. Particulate sampling was carried out at a municipal materials recovery facility near a conveyer belt containing sorted plastic materials to collect airborne environmental particles on filters. Nucleopore filters were mounted on Teflon support rings, coated with 100 nm aluminum to reduce the background signal for micro-Raman spectroscopy, and marked with a fiducial pattern using a laser engraver. The fiducial pattern was crucial in identifying samples, relocating particles, and efficiently enabling orthogonal measurements on the same samples. Optimum sampling conditions of 2 h at 25 L/min were determined using light microscopy to evaluate the particle loadings. The filters were then cut into slices which were attached to sections of thin beryllium-copper sheeting for easy transfer of the filter between microscopy platforms. Scanning electron microscopy was used to identify carbon-rich particles. Light microscopy was used to identify colored particles which were also carbon-rich which were then analyzed using micro-Raman spectroscopy to identify specific polymers. [ABSTRACT FROM AUTHOR]

Plastic pollution has been a topic of grave concern worldwide due to major environmental, economic, health, and social impacts. Nevertheless, our society is far from casting plastics aside since they are essential for several applications (e.g. food packaging, automotive, electronics, building, and construction). Poly(terephtalate ethylene) (PET), an important synthetic polyester derived from petroleum, is extensively used in plastic packaging (mainly bottles and trays). Unfortunately, no greener polymer alternative has large-scale production to meet global demand. Consequently, plastic recycling is the most sustainable approach to manage the massive amounts of post-consumed PET materials, by recovering its monomeric units: terephthalic acid and ethylene glycol. However, current recycling methods are still costly, leading to more expensive reclaimed PET monomers than virgin ones obtained from fossil sources. Recently, PET upcycling emerged as a profitable strategy to value the reclaimed monomers by converting them into molecules with higher added value, enhancing the recycling process viability. In this review, we addressed all valuable commodities produced from the conversion of PET monomers catalyzed by microorganisms, as an eco-friendly process known as biological upcycling or bio-upcycling. We provided an outlook regarding potential markets and highlighted the benefits of the PET bio-upcycling route over the actual industrial production of each commodity. Moreover, we discussed different PET recycling methods employed to recover monomers prior to the bio-upcycling step, highlighting the pros and cons. Additionally, we addressed critical considerations about the major challenges regarding this novel recycling strategy, particularly in upscaling from lab-scale stage to real-world implementation. [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHAs) are intracellular biopolymers that microorganisms use for energy and carbon storage. They are mechanically similar to petrochemical plastics when chemically extracted, but are completely biodegradable. While they have potential as a replacement for petrochemical plastics, their high production cost using traditional carbon sources remains a significant challenge. One potential solution is to modify heterotrophic PHA-producing strains to utilize alternative carbon sources. An alternative approach is to utilize methylotrophic or autotrophic strains. This article provides an overview of bacterial strains employed for PHA production, with a particular focus on those exhibiting the highest PHA content in dry cell mass. The strains are organized according to their carbon source utilization, encompassing autotrophy (utilizing CO2, CO) and methylotrophy (utilizing reduced single-carbon substrates) to heterotrophy (utilizing more traditional and alternative substrates). [ABSTRACT FROM AUTHOR]

Soil conservation is one of the best methods to improve soil fertility and enhance crop growth efficiency. Replacing plastic mulch with biomass is an environmentally friendly strategy. Innovative encapsulated soil granules (ESGs) were developed using PVA/PC film as the wall material and rural soil as the core. The PVA/PC was synthesized using 60% protein polypeptide (PC) from leather waste scrap and 35% poly (vinyl alcohol) (PVA), which was optimized for water absorption expansion and water retention performance. The ESG-10 granulated with 10% PVA/PC exhibited good water absorption, moisture retention, and resistance to water solubility. As an auxiliary material for soil improvement, the amount of ESGs mixed with the topsoil at ratios of 0 g/m2, 200 g/m2, and 400 g/m2 was proportional to the soil insulation and moisture retention. In rapeseed cultivation, the experimental results indicated that the soil mulched with ESG-10 can maintain seedling vitality for a long time under low water content conditions. [ABSTRACT FROM AUTHOR]

Approximately 50% of global plastic wastes are produced from plastic packaging, a substantial amount of which is disposed of within a few minutes of its use. Although many plastic types are designed for single use, they are not always disposable. It is now widely acknowledged that the production and disposal of plastics have led to a plethora of negative consequences, including the contamination of both groundwater and soil resources and the deterioration of human health. The undeniable impact of excessive plastic manufacturing and waste generation on the global plastic pollution crisis has been well documented. Therefore, degradable polymers are a crucial solution to the problem of the non-degradation of plastic wastes. The disadvantage of degradable polymers is their high cost, so blending them with natural polymers will reduce the cost of final products and maximize their degradation rate, making degradable polymers competitive with industrial polymers that are currently in use daily. In this work, we will delineate various degradable polymers, including polycaprolactone, starch, and cellulose. Furthermore, we will elucidate several aspects of polyvinyl alcohol (PVA) and its blends with natural polymers to show the effects of adding natural polymers on PVA properties. This paper will study cost-effective and ecologically acceptable polymers by combining inexpensive natural polymers with readily accessible biodegradable polymers such as polyvinyl alcohol (PVA). [ABSTRACT FROM AUTHOR]

The synthesis of conventional plastics has increased tremendously in the last decades due to rapid industrialization, population growth, and advancement in the use of modern technologies. However, overuse of these fossil fuel-based plastics has resulted in serious environmental and health hazards by causing pollution, global warming, etc. Therefore, the use of microalgae as a feedstock is a promising, green, and sustainable approach for the production of biobased plastics. Various biopolymers, such as polyhydroxybutyrate, polyurethane, polylactic acid, cellulose-based polymers, starch-based polymers, and protein-based polymers, can be produced from different strains of microalgae under varying culture conditions. Different techniques, including genetic engineering, metabolic engineering, the use of photobioreactors, response surface methodology, and artificial intelligence, are used to alter and improve microalgae stocks for the commercial synthesis of bioplastics at lower costs. In comparison to conventional plastics, these biobased plastics are biodegradable, biocompatible, recyclable, non-toxic, eco-friendly, and sustainable, with robust mechanical and thermoplastic properties. In addition, the bioplastics are suitable for a plethora of applications in the agriculture, construction, healthcare, electrical and electronics, and packaging industries. Thus, this review focuses on techniques for the production of biopolymers and bioplastics from microalgae. In addition, it discusses innovative and efficient strategies for large-scale bioplastic production while also providing insights into the life cycle assessment, end-of-life, and applications of bioplastics. Furthermore, some challenges affecting industrial scale bioplastics production and recommendations for future research are provided. [ABSTRACT FROM AUTHOR]

Synthetic polymers, commonly known as plastics, are currently present in all aspects of our lives. Although they are useful, they present the problem of what to do with them after their lifespan. There are currently mechanical and chemical methods to treat plastics, but these are methods that, among other disadvantages, can be expensive in terms of energy or produce polluting gases. A more environmentally friendly alternative is recycling, although this practice is not widespread. Based on the practice of the so-called circular economy, many studies are focused on the biodegradation of these polymers by enzymes. Using enzymes is a harmless method that can also generate substances with high added value. Novel and enhanced plastic-degrading enzymes have been obtained by modifying the amino acid sequence of existing ones, especially on their active site, using a wide variety of genetic approaches. Currently, many studies focus on the common aim of achieving strains with greater hydrolytic activity toward a different range of plastic polymers. Although in most cases the depolymerization rate is improved, more research is required to develop effective biodegradation strategies for plastic recycling or upcycling. This review focuses on a compilation and discussion of the most important research outcomes carried out on microbial biotechnology to degrade and recycle plastics. [ABSTRACT FROM AUTHOR]

Understanding the nuanced interplay between plant polyphenols and starch could have significant implications. For example, it could lead to the development of tailor-made starches for specific applications, from bakinag and brewing to pharmaceuticals and bioplastics. In addition, this knowledge could contribute to the formulation of functional foods with lower glycemic indexes or improved nutrient delivery. Variations in the complexes can be attributed to differences in molecular weight, structure, and even the content of the polyphenols. In addition, the unique structural characteristics of starches, such as amylose/amylopectin ratio and crystalline density, also contribute to the observed effects. Processing conditions and methods will always alter the formation of complexes. As the type of starch/polyphenol can have a significant impact on the formation of the complex, the selection of suitable botanical sources of starch/polyphenols has become a focus. Spectroscopy coupled with chemometrics is a convenient and accurate method for rapidly identifying starches/polyphenols and screening for the desired botanical source. Understanding these relationships is crucial for optimizing starch-based systems in various applications, from food technology to pharmaceutical formulations. [ABSTRACT FROM AUTHOR]

The presence of petroleum‐based monomers in the backbone of poly(butylene succinate‐co‐adipate) (PBSA) restricts its application in light of increasingly stringent environmental regulations. In this study, a novel full bio‐based biodegradable random copolymer poly(butylene succinate‐sebacicate‐salicylicate‐malicate) (PBSSeSa‐c‐M) was designed and synthesized. The comprehensive study encompassed the structural alterations, properties, and degradation resulting from the inclusion of salicylicate sebacicate and malicate units. The incorporation of salicylic acid effectively enhanced the tensile modulus of the copolymer, due to the effect of rigid benzene ring. Meanwhile, the addition of sebacic acid regulated the degradation rate. The introduction of malic acid significantly improved the rheological properties, endowing the copolymer with exceptional processability. The obtained high molecular weight PBSSeSa‐c‐M exhibited outstanding film‐blowing processability with an intrinsic viscosity of 1.58 dL/g and melt flow rate of 7.34 g/10 min. The tensile modulus reaches 235.43 MPa that is comparable to commercial PBSA. Besides, the degradation of PBSSeSa‐c‐M reaches 18.92% over 4 weeks, far higher than that of PBSA. In conclusion, this work provides a design and synthesis for a new kind of biodegradable copolyester that satisfies the requirement of rapid degradation in single‐use plastics. [ABSTRACT FROM AUTHOR]

This work aimed to manufacture bioplastics with mechanical and electrical properties for monitoring the Rhizopus stolonifer growth in tomato fruit packaging. Bioplastics were based on chitosan/polyvinyl alcohol (Ch/PVA), chitosan/polyvinyl pyrrolidone (Ch/PVP), and nanoparticles (NPs) of plant extracts at 10% and 30% of concentrations. Bioplastics were exposed to tomato inoculated with R. stolonifer for 6 d at 25°C. Water vapor permeability (WVP), mechanical properties, FTIR, UV–vis, morphology, electrical resistance of bioplastics, and the NPs size were assessed. In bioplastics added with plant extracts, 1.5 times more WVP than in the control group (18–35 gs−1m−1Pa−1) were quantified. Ch/PVA bioplastic showed 51% more tensile strength, 44% more elongation at break, and 40% more Young's modulus than Ch/PVP, regardless of the plant extract. The electrical resistance in Ch/PVA bioplastics with 30% mushroom extract and 10% radish allowed the differentiation between inoculated (109–1010 Ω) and non‐inoculated tomatoes (1010–1011 Ω). The FTIR assay confirmed the presence of each compound used in the bioplastic, and UV–vis confirmed phenols at 300 nm. The NPs measured less than 50 nm. Only Ch/PVA with 30% mushroom and 10% radish can be useful to monitor fungi in tomatoes based on their electrical behavior. [ABSTRACT FROM AUTHOR]

The escalating environmental challenges posed by petroleum-derived plastics have underscored the urgent need for sustainable and biodegradable alternatives, particularly in the realm of food packaging materials. This study addresses this pressing issue by introducing a novel approach to developing eco-friendly food packaging materials through the application of dialdehyde-modified cellulose (DAC) and polyvinyl alcohol (PVA) coating. This environmentally conscious method involves coating a polylactic acid (PLA) film, a readily available and biodegradable substrate, with an aqueous solution of DAC and PVA. The resultant a-PLA/h-DAC1-PVA0.5 films exhibit exceptional gas barrier properties, attributed to effective crosslinking between DAC and PVA, surpassing the performance of both conventional PLA films and aluminum oxide-deposited PLA counterparts. Furthermore, these films offer optical and electromagnetic transparency, essential for monitoring food freshness and enabling QR code and RFID recognition. Importantly, extensive biodegradability assessments reveal that our films, primarily composed of PLA with a cellulose-based coating layer, align with established PLA degradation kinetics. Notably, these films demonstrate non-cytotoxicity, affirming their suitability for widespread use. This innovative approach presents a promising solution for the development of sustainable, biodegradable, and highly transparent food packaging materials, contributing significantly to plastic waste reduction and environmental preservation within the food industry. [ABSTRACT FROM AUTHOR]

Global environmental concerns have recently accelerated interest in the usage of biodegradable polymers to replace petroleum-based conventional plastics. Lactic acid-based polymers are some of the most promising and widely studied biobased materials, which are suitable for packaging and biomedical applications. This is mainly due to their appealing characteristics such as relatively good mechanical properties, biocompatibility, and multiple end-of-life options such as recyclability and biodegradability in industrial composting conditions. However, the use of lactic acid-based polymers in advanced applications is constrained by their inherent brittleness, poor melt strength, and relatively high cost. These disadvantages can be remedied by reinforcement with cellulose nanomaterials which can enhance their mechanical properties while maintaining their biodegradability. This review provides an overview of recent studies on the development of biodegradable lactic acid-based polymer composites and nanocomposites reinforced with cellulose nanofibrils (CNFs), cellulose nanocrystals (CNCs) and microcrystalline cellulose (MCC). The different processing methods and chemical modification techniques utilised on modification and functionalisation of cellulosic nanomaterials for improving the properties of lactic acid-based polymer nanocomposites are also discussed. [ABSTRACT FROM AUTHOR]

Nowadays, the world is facing a general problem of resource overconsumption and waste overproduction: to address these two issues, the United Nations delivered the 12th Sustainable Development Goal (SDG), which has the objective of ensuring sustainable consumption and production patterns. Currently, polymers are present in every aspect of our lives and have the disadvantage of mostly coming from fossil sources and causing pollution when disposed of the wrong way. Agriculture plays a key role in the overall world environmental issues, being responsible for the creation of between 13 and 21% of global greenhouse gas (GHG) emissions. Moreover, it represents a continuously growing field, producing large amounts of waste. These residues can cause serious environmental concerns and high costs when disposed. However, agri-food waste (AFW) is a natural source of natural biopolymers, such as lignin, cellulose, pectin, and starch, but can also be used as a substrate to produce other non-toxic and biodegradable biopolymers, such as chitosan, polyhydroxyalkanoates (PHAs), and polylactic acid (PLA) through microbial fermentation. These polymers find applications in agricultural practices such as mulching films, soil stabilizers, hydrogels, nanocarriers, and coating for seeds, fruits, and vegetables. The employment of AFW in the production of non-toxic, sustainable, and biodegradable biopolymers for their agricultural utilization is an example of a virtuous circular economy approach that could help agriculture to be more sustainable. [ABSTRACT FROM AUTHOR]

This study presents a novel hydrophobic lignocellulosic bioplastic from corn stover reinforced by oxidized cellulose and in situ regenerated lignin. Cellulose‐lignin mixture as a matrix was obtained by acid‐recyclable deep eutectic solvent (DES) pretreatment of corn stover in mild conditions. Triethoxy(octyl)silane (C14H32O3Si) was employed to improve the water stability of the bioplastic by vapor deposition. The results show that the hydrophobic bioplastic has a high tensile strength, measuring 62.36 MPa. The water contact angle of the bioplastic was increased from 8.50° to 121.9° after hydrophobic modification. We prepared oxidized cellulose‐reinforced cellulose paper by different particle size distributions of oxidized cellulose to investigate the reinforcement of oxidized cellulose. The tensile strength of oxidized cellulose cellulose paper increased from 14.41 to 21.18 MPa with the addition of oxidized cellulose. The zeta potential of oxidized cellulose is −47.99 mV, which shows a more negative charge due to carbonyl groups. The repulsive force of oxidized cellulose contributes to the formation of a brick‐and‐mortar microstructure with cellulose‐lignin mixture. It demonstrates that oxidized cellulose can act as bio‐adhesives and has a good toughening effect on the mechanical properties of bioplastic. Highlights: Lignocellulosic bioplastic was prepared by DES pretreatment of corn stover.Oxidized cellulose was used to reinforce the lignocellulosic bioplastic.The tensile strength of the bioplastic was 62.36 MPa after the reinforcement process.Trieth‐oxy(octyl)silane was employed to improve water stability.The water contact angle of the bioplastic was increased from 8.50° to 121.9°. [ABSTRACT FROM AUTHOR]

The biodegradable materials cannot meet the requirements as the agricultural film due to the poor UV resistance and antidripping performance. The work herein thus presented the development of the green‐based anti‐ultraviolet and antidripping multifunctional composite films using poly(butyleneadipate‐co‐terephthalate), microfibrillated cellulose (MFC), and soybean protein isolate (SPI) as the raw materials in the presence of other agents. The resulting composite films were systematically characterized using scanning electron microscope, thermogravimetry analysis (TG), UV, and rheometer measurements. The morphology changed obviously after introducing the MFC and SPI into the substrate film. In addition, the results indicated that the addition of MFC and SPI had a positive effect on the thermal stability and heat preservation of the film, respectively. The contact angle results indicated that SPI was an ideal antidripping agent and the MFC could be used as the release agent. The time of the first water drop of the film containing 2.5 g MFC and 2.0 g SPI was 6 min and 46 s, and the time of each 10 drops was less than 60 s, showing the advantages of using MFC as the release agent and SPI as the antidripping agent. The resulting multifunctional biodegradable films can be widely used in the agricultural and packaging fields. [ABSTRACT FROM AUTHOR]

α-zeins are amphiphilic maize seed storage proteins with material properties suitable for a multitude of applications e.g., in renewable plastics, foods, therapeutics and additive manufacturing (3D-printing). To exploit their full potential, molecular-level insights are essential. The difficulties in experimental atomic-resolution characterization of α-zeins have resulted in a diversity of published molecular models. However, deep-learning α-zein models are largely unexplored. Therefore, this work studies an AlphaFold2 (AF2) model of a highly expressed α-zein using molecular dynamics (MD) simulations. The sequence of the α-zein cZ19C2 gave a loosely packed AF2 model with 7 α-helical segments connected by turns/loops. Compact tertiary structure was limited to a C-terminal bundle of three α-helices, each showing notable agreement with a published consensus sequence. Aiming to chart possible α-zein conformations in practically relevant solvents, rather than the native solid-state, the AF2 model was subjected to MD simulations in water/ethanol mixtures with varying ethanol concentrations. Despite giving structurally diverse endpoints, the simulations showed several patterns: In water and low ethanol concentrations, the model rapidly formed compact globular structures, largely preserving the C-terminal bundle. At ≥ 50 mol% ethanol, extended conformations prevailed, consistent with previous SAXS studies. Tertiary structure was partially stabilized in water and low ethanol concentrations, but was disrupted in ≥ 50 mol% ethanol. Aggregated results indicated minor increases in helicity with ethanol concentration. β-sheet content was consistently low (∼1%) across all conditions. Beyond structural dynamics, the rapid formation of branched α-zein aggregates in aqueous environments was highlighted. Furthermore, aqueous simulations revealed favorable interactions between the protein and the crosslinking agent glycidyl methacrylate (GMA). The proximity of GMA epoxide carbons and side chain hydroxyl oxygens simultaneously suggested accessible reactive sites in compact α-zein conformations and pre-reaction geometries for methacrylation. The findings may assist in expanding the applications of these technologically significant proteins, e.g., by guiding chemical modifications. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA), a biomass material, has garnered increasing interest as a biodegradable alternative for the production of eco-friendly plastics. Accordingly, the sustainable synthesis of lactic acid (LA) and its derivatives from biomass sources is emerging as a viable approach. In this work, an In-TS-1 zeolite with exceptional catalytic activity and stability was successfully synthesized using a hydrothermal method and applied for the efficient one-pot conversion of fructose into methyl lactate (MLA). Characterization of the resulting catalysts, including pyridine-adsorbed Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, and energy dispersive X-ray spectroscopy for elemental mapping, confirmed that the uniform dispersion of indium (In) species contributed to its favorable acidity and significantly boosted the reaction efficiency. Under optimized reaction conditions, a remarkable MLA yield of 71.9% was achieved upon the complete conversion of fructose. The selectivity of MLA remained consistent over 14 cycles, underscoring its extraordinary stability under hydrothermal conditions attributed to the confinement of In species within the zeolite framework. This research technique establishes a potential strategy for the large-scale manufacture of LA and its esters, offering a sustainable and efficient path for the development of biodegradable plastics. [ABSTRACT FROM AUTHOR]

This review article provides a thorough overview of barrier coating materials that have been used in food packaging with a focus on biodegradable (bio-based or petroleum-based) materials, such as lipids, proteins, polysaccharides, agriculture waste and polyesters. The goal is to provide an opportunity to acknowledge progress made in this field, focusing on modifications made to coatings. These modifications aim to address the shortcomings of biodegradable substrates (either plastic or paper) and improve their performance, enabling them to compete with traditional petroleum-based food packaging materials. This includes their barrier against water vapor and oxygen, mechanical and surface characteristics (sealability and adhesion), as well as antimicrobial properties. The barrier of most biodegradable polymers underperforms in comparison with petroleum-based non-biodegradable polymers, which possess either high water vapor barrier or high oxygen barrier. Coating technology is a promising solution particularly in barrier improvement of biodegradable polymers. Currently, there are only metallized, or inorganic nanosheet coatings available for biodegradable films that meet food packaging requirements. There are some challenges in this field, for example, being able to retain the coating's biodegradability despite applied modifications to improve it's performance, the large-scale fabrication of biodegradable coatings, the coating's delamination and heat-sealability during service time, and the migration of the coating into the packaged food. Moreover, green chemistry and its sustainability needs in biodegradable polymeric coatings are also discussed regarding new ideas and possible directions for widespread application of coatings in food packaging. This is the first review that specifically summarizes biodegradable coatings on plastic and paper substrates with a focus on coating modifications to improve the performance of the base substrate to meet the required properties for food packaging applications. [ABSTRACT FROM AUTHOR]

Microbeads find widespread usage in personal care items and cosmetics, serving as exfoliants or scrubbing agents. Their micro-scale size poses challenges in effective drainage capture and given their origin from non-biodegradable oil-based plastics, this contributes substantially to marine pollution. In this study, microbeads were prepared by a simple yet scalable melt homogenization method using four types of polyhydroxyalkanoates (PHA), namely poly[(R)-3-hydroxybutyrate] (P(3HB)), poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (P(3HB-co-3HV)), poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (P(3HB-co-3HHx)) and poly[(R)-3-hydroxybutyrate-co-(R)-4-hydroxyvalerate] (P(3HB-co-4HB)). Microbeads with different surface smoothness, compressive strength (6.2–13.3 MPa) and diameter (from 1 ~ 150 μm) could be produced. The microbeads were subjected to a comprehensive degradation analysis using three techniques: enzymatic, Biochemical Oxygen Demand (BOD) evaluations, and in situ degradation tests in the deep-sea off Misaki Port in the northern Pacific Ocean (depth of 757 m). Qualitatively, results from enzymatic and in situ degradation demonstrated significant degradation within one week and five months, respectively. Quantitatively, BOD findings indicated that all PHA microbeads degraded similarly to cellulose (~ 85% biodegradability in 25 days). In conclusion, PHA microbeads from this study exhibit promising potential as alternatives to conventional non-biodegradable microbeads. [ABSTRACT FROM AUTHOR]

In this study, hydrothermal co-liquefaction of restaurant waste for biocrude production was conducted. The feedstock was resembled using the organic fraction of restaurant waste and low-density polyethylene, polypropylene, polystyrene, and polyethylene terephthalate, four plastic types commonly present in municipal solid waste. Using design of experiment and a face-centered central composite design, three factors (feedstock plastic fraction, temperature, time) were varied at three levels each: feedstock plastic fraction (0, 0.25, 0.5), temperature (290 °C, 330 °C, 370 °C), and reaction time (0 min, 30 min, 60 min). The literature reports positive synergistic interactions in hydrothermal co-liquefaction of biomass and plastics; however, in this work, only negative synergistic interactions could be observed. A reason could be the high thermal stability of produced fatty acids that give little room for interactions with plastics. At the same time, mass might transfer to other product phases. [ABSTRACT FROM AUTHOR]

In the recent decade, nanoparticles (NPs) have had enormous implications in cancer biomedicine, including research, diagnosis, and therapy. However, their broad application still faces obstacles due to some practical limitations and requires further development. Recently, there has been more interest in the coated class of nanoparticles to address those challenges. Chitosan‐coated NPs are simple to produce, biodegradable, biocompatible, exhibit antibacterial activity, and have less cytotoxicity. This study provides an updated and comprehensive overview of the application of chitosan‐coated NPs as a promising class of NPs in cancer biomedicine. Additionally, we discussed chitosan‐coated lipid, metal, and polymer‐based nanoparticles in biomedical applications. Furthermore, different coating methods and production/characterization procedures were reviewed. Moreover, the biological and physicochemical advantages of chitosan‐coated NPs, including facilitated controlled release, greater physicochemical stability, improved cell/tissue interaction, and enhanced bioavailability of medications, were highlighted. Finally, the prospects of chitosan‐coated NPs in cancer biomedicine were discussed. [ABSTRACT FROM AUTHOR]

2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable pseudo-aromatic dicarboxylic acid, is a promising building block compound for manufacturing biodegradable polyesters. This study aimed to construct high-performance cell factories enabling the efficient production of PDC from glucose. Firstly, the effective enzymes of the PDC biosynthetic pathway were overexpressed on the chromosome of the 3-dehydroshikimate overproducing strain. Consequently, the one-step biosynthesis of PDC from glucose was achieved. Further, the PDC production was enhanced by multi-copy integration of the key gene PsligC encoding 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase and co-expression of Vitreoscilla hemoglobin. Subsequently, the PDC production was substantially improved by redistributing the metabolic flux for cell growth and PDC biosynthesis based on dynamically downregulating the expression of pyruvate kinase. The resultant strain PDC50 produced 129.37 g/L PDC from glucose within 78 h under fed-batch fermentation conditions, with a yield of 0.528 mol/mol and an average productivity of 1.65 g/L/h. The findings of this study lay the foundation for the potential industrial production of PDC. • Biosynthesis of PDC from glucose was achieved in E. coli by combinatorial pathway engineering. • Heterologous expression of hemoglobin was used to increase PDC production. • Dynamic downregulation of pykA was employed to balance cell growth and PDC biosynthesis. • An efficient cell factory enabling potential industrial production of PDC was constructed. [ABSTRACT FROM AUTHOR]

Plastics offer many advantages and are widely used in various fields. Nevertheless, most plastics derived from petroleum are slow to degrade due to their stable polymer structure, posing serious threats to organisms and ecosystems. Thus, developing environmentally friendly and biodegradable plastics is imperative. In this study, biodegradable cellulose/multi-walled carbon nanotube (MCNT) hybrid gels and films with improved ultraviolet-shielding properties were successfully prepared using cotton textile waste as a resource. It was proven that MCNTs can be dispersed evenly in cellulose without any chemical or physical pretreatment. It was found that the contents of MCNTs had obvious effects on the structures and properties of hybrid films. Particularly, the averaged transmittance of cellulose/MCNT composite films in the range of 320–400 nm (T320–400) and 290–320 nm (T290–320) can be as low as 19.91% and 16.09%, when the content of MCNTs was 4.0%, much lower than those of pure cellulose films (T320–400: 84.12% and T290–320: 80.03%). Meanwhile, the water contact angles of the cellulose/MCNT films were increased by increasing the content of MCNTs. Most importantly, the mechanical performance of cellulose/MCNT films could be controlled by the additives of glycerol and MCNTs. The tensile strength of the cellulose/MCNT films was able to reach as high as 20.58 MPa, while the elongation at break was about 31.35%. To summarize, transparent cellulose/MCNT composites with enhanced ultraviolet-shielding properties can be manufactured successfully from low-cost cotton textile waste, which is beneficial not only in terms of environmental protection, but also the utilization of natural resources. [ABSTRACT FROM AUTHOR]

The improper disposal of plastics is a growing concern due to increasing global environmental problems such as the rise of CO2 emissions, diminishing petroleum sources, and pollution, which necessitates the research and development of biodegradable materials as an alternative to conventional packaging materials. The purpose of this research was to analyse the properties of biodegradable polymer blends of thermoplastic potato starch (TPS) and polylactide, (PLA) without and with the addition of citric acid (CA) as a potential compatibilizer and plasticizer. The prepared blends were subjected to a comprehensive physicochemical characterization, which included: FTIR-ATR spectroscopy, morphological analysis by scanning electron microscopy (SEM), determination of thermal and mechanical properties by differential scanning calorimetry (DSC), water vapour permeability (WVP), as well as biodegradation testing in soil. The obtained results indicate an improvement in adhesion between the TPS and PLA phases due to the addition of citric acid, better homogeneity of the structure, and greater compatibility of the polymer blends, leading to better thermal, mechanical and barrier properties of the studied biodegradable TPS/PLA polymer blends. After conducting the comprehensive research outlined in this paper, it has been determined that the addition of 5 wt.% of citric acid serves as an effective compatibilizer and plasticizer. This supplementation achieves an optimal equilibrium across thermal, mechanical, morphological, and barrier properties, while also promoting material sustainability through biodegradation. In conclusion, it can be stated that the use of thermoplastic starch in TPS/PLA blends accelerates the biodegradation of PLA as a slowly biodegradable polymer. While the addition of citric acid offers significant advantages for TPS/PLA blends, further research is needed to optimize the formulation and processing parameters to achieve the desired balance between mechanical strength, thermal and barrier properties and biodegradability. [ABSTRACT FROM AUTHOR]

The surge in global utilization of petroleum-based plastics, which notably heightened during the COVID-19 pandemic, has substantially increased its harm to ecosystems. Considering the escalating environmental impact, a pivotal shift towards bioplastics usage is imperative. Exploring and implementing bioplastics as a viable alternative could mitigate the ecological burden posed by traditional plastics. Macroalgae is a potential feedstock for the production of bioplastics due to its abundance, fast growth, and high cellulose and sugar content. Researchers have recently explored various methods for extracting and converting macroalgae into bioplastic. Some of the key challenges in the production of macroalgae bioplastics are the high costs of large-scale production and the need to optimize the extraction and conversion processes to obtain high-quality bioplastics. However, the potential benefits of using macroalgae for bioplastic production include reducing plastic waste and greenhouse gas emissions, using healthier materials in various life practices, and developing a promising area for future research and development. Also, bioplastic provides job opportunities in free enterprise and contributes to various applications such as packaging, medical devices, electronics, textiles, and cosmetics. The presented review aims to discuss the problem of petroleum-based plastic, bioplastic extraction from macroalgae, bioplastic properties, biodegradability, its various applications, and its production challenges. [ABSTRACT FROM AUTHOR]

In light of increasing apprehensions surrounding the environmental impact of non-biodegradable plastics, there has been a surge in the exploration of biodegradable films as a viable and sustainable alternative. This research has focused on developing Tara gum (TG)-based films incorporated with Lavender essential oil (LEO) at different concentrations (5–20% w/w) to improve the properties of the films. According to the results, GC-MS analysis confirmed the presence of linalool and linalyl acetate as the major compounds in LEO. Among the composite films, the sample containing 5% (w/w) LEO exhibited the highest homogeneity, as evidenced by SEM micrographs, and the CLSM image demonstrated the absence of any clustering or coalescence of LEO within this film. FTIR spectra demonstrated intermolecular interactions between TG and LEO, as evidenced by a new peak at 1458 cm−1 in the LEO-loaded films. The addition of LEO resulted in a significant decrease in the water content (WC) and water solubility (WS) of the films. Furthermore, LEO incorporation improved the contact angle (CA) of the films up to 1.5 times. The TG-LEO films exhibited good transparency, higher elongation at break (EB), and lower Young's modulus (YM). Additionally, LEO positively affected the antioxidant and antimicrobial properties of the films. Overall, the results authenticated the hypothesis of this study and indicated that TG-LEO films have great potential as biodegradable films with promising functionalities for food packaging applications. [ABSTRACT FROM AUTHOR]

The topic of riverine microplastics is of great interest to the general public, yet the univocal scientific knowledge on this topic is limited. This review investigated the occurrence of microplastics in 6 major European rivers and their tributaries based on the results from 29 studies. We examined the reviewed studies in regard to data quality and reproducibility and assessed the abundance of microplastics in different sections of the water column. Furthermore, we investigated the chemical composition and potential origin of the reported riverine microplastics. We found that polystyrene, polypropylene, and polyethylene were the most abundant polymer types. The majority of primary microplastics arose from the industry sector as well as from personal care and cleaning products, whereas secondary microplastics constituted fibers from synthetic textiles and fragments of diverse origins. We highlighted the diversity of experimental and analytical approaches that could lead to high uncertainties in the measurements of microplastics abundance. Furthermore, the presence of microplastics in rivers was found to vary spatially likely due to point and nonpoint pollution sources of anthropogenic activities. Heterogenous environmental processes impacted the fate of microplastics characterized by various forms, sizes, and densities, in different ways. This impeded the identification of representative quantitative measurements of microplastics across different time frames. We advocate for the development of standardized protocols by the research community to ensure higher reproducibility of sampling, processing, and analysis of microplastics in aquatic environments. We recommend long‐term and site‐specific monitoring on microplastics with high data comparability to better inform policy making. This article is categorized under:Science of Water > Water QualityWater and Life > Conservation, Management, and Awareness [ABSTRACT FROM AUTHOR]

This comprehensive review addresses the vital environmental concerns posed by conventional petroleum-based plastics, particularly in the context of the packaging industry's extensive reliance on these materials. As nearly 99% of plastics originate from non-renewable petrochemical sources and their non-biodegradable nature leads to widespread waste accumulation and harmful emissions upon disposal, the need for sustainable alternatives has become paramount. This paper explores the escalating environmental and health repercussions linked to traditional plastics, underscored by global initiatives, including restrictions on single-use plastics, aimed at mitigating these challenges. In response, the paper highlights the growing interest in environmental friendly biopolymers, which can be sourced from renewable biological materials or synthesized from biopolymers such as starch, casein etc. The classification of biopolymers into three primary categories; natural biopolymers, microbial fermentation-derived biopolymers, and polymerized monomers from biomass is comprehensively examined. Furthermore, the paper emphasizes the pivotal role of biopolymer properties, such as barrier characteristics, mechanical strength, heat resistance, biodegradability, flexibility, food contact safety, and cost-effectiveness, in determining their suitability for packaging applications. It also stresses the importance of conducting life cycle assessment (LCA) to holistically evaluate the environmental sustainability of biopolymers. This review highlights the potential of integrating biopolymers into packaging materials as a promising avenue to reduce the adverse environmental impact of traditional plastic production. These biodegradable materials, with their diverse properties and renewability, offer a sustainable approach to mitigating plastic waste and lowering greenhouse gas emissions. However, further research, development, and collaborative efforts are essential to optimize biopolymer performance, reduce production costs, and facilitate broader adoption. Embracing biodegradable polymers represents a commitment to resource efficiency, waste reduction, and environmental preservation, fostering a more sustainable and ecofriendly future. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrophobic ZIF-8/SA monolithic materials were fabricated via in situ synthesis. • The cooperation of SA, PDMS, and ZIF-8 significantly enhanced adsorption capacity. • The composites displayed rapid kinetic adsorption. • The composites have remarkable absorption recyclability. Microplastics (MPs), a newly emerging class of environmental contaminants, pose a severe threat to the entire ecosystem. The development of efficient and environmentally responsible adsorbents for removing the MPs is a particularly urgent research. Herein, a kind of monolithic ZIF-8 based adsorbents featuring stable hydrophobicity and micropore-mesopore-macropore hierarchical porous structure were fabricated by in situ growth of ZIF-8 nanoparticles on sodium alginate (SA) framework, and using polydimethylsiloxane (PDMS) as a hydrophobic agent. The monolithic nature of ZIF-8/SA allowed an easy solid–liquid separation process for adsorbents from water environment compared to powdered materials. The hierarchical porous structure ensures a remarkable MPs removal performance. The ZIF-8/SA showed high adsorption capacities of 594, 585, and 282 mg/g for polymethyl methacrylate (PMMA), poly (vinylidene difluoride) (PVDF), and polyvinyl chloride (PVC) respectively, and rapid adsorption kinetic progress within 120 min. The ZIF-8/SA adsorbents also exhibited excellent stability in the presence of interfering ions, acid/alkali, and humic acid, and displayed adsorption performance of > 70 % even in actual aquatic environment such as tap water, river water, and seawater. The results of characterizations showed that the synergistic effect of electrostatic interaction, hydrogen bonding, hydrophobic force, and van der Waals force was the main adsorption mechanism. The well-designed hydrophobic ZIF-8/SA monolithic materials would be promising to rapidly remove the MPs from the water environment. [ABSTRACT FROM AUTHOR]

A nonthermal, pulsed spark discharge is applied to three polymer powders in Ar and Ar–H2 ${{\rm{H}}}_{2}$ gas mixtures. Hydrogen is introduced to assess plasma‐driven decomposition. Gaseous decomposition products, including methane, acetylene, and ethylene, are observed with Fourier‐transform infrared (FTIR). Surface modifications are observed on the residual polymer via attenuated total internal reflection‐FTIR. Time‐averaged rotational, vibrational, and excitation temperatures are characterized in the discharge. The plasma density is found to be around 3×1022 m−3 $3\times 1{0}^{22}\unicode{x0200A}{{\rm{m}}}^{-3}$, with rotational and vibrational temperatures ranging from 1500 to 2200 K and an excitation temperature of 1–2 eV. While spark properties did not change with either gas composition or polymer composition, it was determined that the addition of hydrogen promoted higher concentrations of gaseous phase products (promoting hydrogenolysis). [ABSTRACT FROM AUTHOR]

Plastic biodegradation has emerged as a sustainable approach and green alternative in handling the ever-increasing accumulation of plastic wastes in the environment. The complete biodegradation of polyethylene terephthalate is one of the most recent breakthroughs in the field of plastic biodegradation. Despite the success, the effective and complete biodegradation of a wide variety of plastics is still far from the practical implementation, and an on-going effort has been mainly devoted to the exploration of novel microorganisms and enzymes for plastic biodegradation. However, alternative strategies which enhance the existing biodegradation process should not be neglected in the continuous advancement of this field. Thus, this review highlights various strategies which have shown to improve the biodegradation of plastics, which include the pretreatment of plastics using UV irradiation, thermal, or chemical treatments to increase the susceptibility of plastics toward microbial action. Alternative pretreatment strategies are also suggested and compared with the existing techniques. Besides, the effects of additives such as pro-oxidants, natural polymers, and surfactants on plastic biodegradation are discussed. In addition, considerations governing the biodegradation performance, such as the formulation of biodegradation medium, cell-free biocatalysis, and physico-chemical properties of plastics, are addressed. Lastly, the challenges and future prospects for the advancement of plastic biodegradation are also highlighted. [ABSTRACT FROM AUTHOR]

Facile construction of a fully biodegradable spherical nucleic acid (SNA) nanoplatform is highly desirable for clinical translations but remains rarely explored. We developed herein the first polycarbonate-based biodegradable SNA nanoplatform for self-codelivery of a chemotherapeutic drug, doxorubicin (DOX), and a human liver-specific miR122 for synergistic chemo-gene therapy of hepatocellular carcinoma (HCC). Ring-opening polymerization (ROP) of a carbonate monomer leads to a well-defined polycarbonate backbone for subsequent DOX conjugation to the pendant side chains via acidic pH-cleavage Schiff base links and miR122 incorporation to the chain termini via click coupling, affording an amphiphilic polycarbonate-DOX-miR122 conjugate, PBis-Mpa 30 -DOX-miR122 that can self-assemble into stabilized SNA. Besides the desired biodegradability, another notable merit of this nanoplatform is the use of miR122 not only for gene therapy but also for enhanced innate immune response. Together with the ICD-triggering effect of DOX, PBis-Mpa 30 -DOX-miR122 SNA-mediated DOX and miR122 codelivery leads to synergistic immunogenicity enhancement, resulting in tumor growth inhibition value (TGI) of 98.1 % significantly higher than those of the groups treated with only drug or gene in a Hepa1-6-tumor-bearing mice model. Overall, this study develops a useful strategy toward biodegradable SNA construction, and presents a drug and gene-based self-codelivery SNA with synergistic immunogenicity enhancement for efficient HCC therapy. Facile construction of a fully biodegradable SNA nanoplatform is useful for in vivo applications but remains relatively unexplored likely due to the synthetic challenge. We report herein construction of a polycarbonate-based SNA nanoplatform for co-delivering a chemotherapeutic drug, DOX, and a human liver-specific miR-122 for synergistic HCC treatment. In addition to the desired biodegradability properties, this SNA nanoplatform integrates DOX-triggered ICD and miR-122-enhanced innate immunity for simultaneously activating adaptive and innate immunities, which leads to potent antitumor efficiency with a TGI value of 98.1 % in a Hepa1-6-tumor-bearing mice model. [Display omitted] [ABSTRACT FROM AUTHOR]

Currently, microplastics (MPs) are considered as emerging aqueous pollutants. However, existing methods for the separation and treatment of MPs from an aquatic environment are limited by their low efficiency. Advanced oxidation processes (AOPs) are novel techniques that employ photo-induced electron/hole pairs to generate active radicals for MP mineralization. Thus, in this study, a photocatalyst, i.e., Ag+ ion-doped TiO2, heterojunctioned with carbon nanotubes (CNT), was synthesized to study the degradation of typical MPs such as polystyrene (PS) under solar irradiation. Effectiveness of the prepared photocatalyst for the PS degradation was estimated through FESEM, FTIR, total organic carbon (TOC) analyzer, and gas chromatography-mass spectroscopy (GC–MS). Quantitatively, 31.7% degradation of PS microbeads was achieved within 48 h. Therefore, this study provides an efficient and cost-effective strategy for the degradation of MPs from the aqueous medium. [ABSTRACT FROM AUTHOR]

The ubiquitous proximity of the commonly used microplastic (MP) particles particularly polyethylene (PE), polypropylene (PP), and polystyrene (PS) poses a serious threat to the environment and human health globally. Biological treatment as an environment-friendly approach to counter MP pollution has recent interest when the bio-agent has beneficial functions in their ecosystem. This study aimed to utilize beneficial floc-forming bacteria Bacillus cereus SHBF2 isolated from an aquaculture farm in reducing the MP particles (PE, PP, and PS) from their environment. The bacteria were inoculated for 60 days in a medium containing MP particle as a sole carbon source. On different days of incubation (DOI), the bacterial growth analysis was monitored and the MP particles were harvested to examine their weight loss, surface changes, and alterations in chemical properties. After 60 DOI, the highest weight loss was recorded for PE, 6.87 ± 0.92%, which was further evaluated to daily reduction rate (k), 0.00118 day−1, and half-life (t1/2), 605.08 ± 138.52 days. The OD value (1.74 ± 0.008 Abs.) indicated the higher efficiency of bacteria for PP utilization, and so for the colony formation per define volume (1.04 × 1011 CFU/mL). Biofilm formation, erosions, cracks, and fragments were evident during the observation of the tested MPs using the scanning electron microscope (SEM). The formation of carbonyl and alcohol group due to the oxidation and hydrolysis by SHBF2 strain were confirmed using the Fourier transform infrared spectroscopic (FTIR) analysis. Additionally, the alterations of pH and CO2 evolution from each of the MP type ensures the bacterial activity and mineralization of the MP particles. The findings of this study have confirmed and indicated a higher degree of biodegradation for all of the selected MP particles. B. cereus SHBF2, the floc-forming bacteria used in aquaculture, has demonstrated a great potential for use as an efficient MP-degrading bacterium in the biofloc farming system in the near future to guarantee a sustainable green aquaculture production. [ABSTRACT FROM AUTHOR]