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Lignosulfonate (LS) was successfully introduced into the epoxy resin matrix with the aid of ethylene glycol (EG) dissolution. Both the rigid LS and soft EG segments were linked into the cross-linked network structure of epoxy resin via esterification of hydroxyl groups in LS and EG molecules with anhydride. The ultimate properties of cured samples were adjusted effectively by changing the proportion of LS and EG components. Curing reaction and kinetics were analyzed, by which the optimal curing process parameters were determined. Although thermal stability of LS itself was relatively lower than that of neat epoxy, the thermal performance was significantly enhanced for the modified sample of epoxy/LS0.5-EG0.5. At the same time, the flexural strength, flexural modulus and impact strength were found to be increased by 23.1, 35.7 and 15.1% respectively compared with the neat epoxy. In addition, the excellent shape memory behavior and improved mechanical stability with LS addition were exhibited by the cured LS-EG modified specimens. This work reveals that lignin can be used as an efficient functional additive to regulate thermal, mechanical and shape memory properties of epoxy resin.

Rice starch has been used in various agri-food products due to its hypoallergenic properties. However, rice starch has poor solubility, lower resistant starch content with reduced retrogradation and poor functional properties. Hence, its industrial applications are rather limited. The lack of comprehensive information and a holistic understanding of the interaction between rice starch and endo/exogenous constituents to improve physico-chemical properties is a prerequisite in designing industrial products with enhanced functional attributes. In this comprehensive review, we highlight the potentials of physically mixing of biopolymers in upgrading the functional characteristics of rice starch as a raw material for industrial applications. Specifically, this review tackles rice starch modifications by adding natural/synthetic polymers and plasticizers, leading to functional blends or composites in developing sustainable packaging materials, pharma- and nutraceutical products. Moreover, a brief discussion on rice starch chemical and genetic modifications to alter starch quality for the deployment of rice starch industrial application is also highlighted.

Nanotechnology has proven as progressive technology that enables to contribute, develop several effective and sustainable changes in food products. Incorporating nanomaterials like TiO2, SiO2, Halloysite nano clay, Copper sulfide, Bentonite nano clay, in carrageenan to develop innovative packaging materials with augmented mechanical and antimicrobial properties along with moisture and gas barrier properties that can produce safe and healthy foods. Intervention of carrageenan-based bio-nanocomposites as food packaging constituents has shown promising results in increasing the shelf stability and food quality by arresting the microbial growth. Nanomaterials can be incorporated within the carrageenan for developing active packaging systems for continuous protection of food products under different storage environments from farm to the fork to ensure quality and safety of foods. Carrageenan based bio nanocomposite packaging materials can be helpful to reduce the environmental concerns due to their high biodegradability index. This review gives insight about the current trends in the applications of carrageenan-based bio nanocomposites for different food packaging applications.

Bio-based additives received significant attention in pulp and paper properties improvement. For this, the most cited biochemical Cellulose Nano Fibrils (CNFs) and Cationic Starch (CS) were experimentally compared with the most declared synthetic chemical, Cationic Polyacrylamide (CPAM). SEM images showed better paper surface filling by the utilization of the chemicals. The three studied polymers, in solely or combination mechanism, improved mainly bagasse pulp and paper properties compared to the blank sample, except for pulp drainage, which decreased by CNFs to lower volumes presumably due to its intrinsic characteristics. Cationic polymers (CP) compared to CP/CNFs approaches increased pulp retention and drainage but decreased paper density and strengths. The best pulp retention and drainage achieved by CS followed by CPAM, while paper air persistency, density, and strength properties evaluated highest by CP/CNFs followed by CNFs. Generally, CS revealed a more significant improvement in pulp and paper properties than CPAM either with or without CNFs.

Contamination caused by the accumulation of petrochemical-based plastics has reached worrying magnitudes and led to the development of biopolymers as an option to mitigate the problem. This work thus presents a bibliometric analysis of all that concerns the development of such bionanocomposite materials, using ScientoPy and SciMAT software to establish associations between the number of published documents, countries, institutions and most relevant topics. The bionanocomposites topic was found to throw up the biggest number of documents associated (2008) with the different types of raw materials and methods used to obtain nanoparticles and their combination with biopolymeric materials, the result known as a “bionancomposite*”. Analysis of the documents related to the application for development of packaging materials from biological molecules, carbohydrate polymers, compounds, conjugates, gels, glucans, hydrogels, membranes, mucilage (source unspecified), mucoadhesives, paper, polymers, polysaccharide, saccharides etc, is also presented, emphasizing mechanical, thermal and barrier properties, which, due to the inclusion of nanoparticles mainly from natural sources of cellulose, show increases of up to 30%. The inclusion of nanoparticles, especially those derived from cellulose sources, generally seeks to increase the properties of bionanocomposite materials. Regarding an increase in mechanical properties, specifically tensile strength, inclusions at percentages not exceeding 10 wt% can register increases that exceed 30% were reported.

Background: The denture-base acrylic resins used by partially edentulous patients can cause local demineralization of teeth. Alkali ions released from the bioactive materials that were added to acrylic resins can increase the pH of the oral environment and slow down the demineralization process. Aim of the study: This study aimed to create a new denture-base acrylic resin that can release ions. Materials and methods: A total of 222 samples with different fillers (calcium hydrogen phosphate, hydroxyapatite, two kinds of bioactive glasses, and a product obtained by reaction between bioactive glass formed from glass ionomer cement and polyacrylic acid) were prepared for the study. All the materials were tested for mechanical properties and their use as phosphate donors for 3 weeks. The measurements were presented as mean ± SD error of the mean. Data were analyzed by two-way analysis of variance, with a p-value of

Sclareol is a labdane diterpene which carries on a broad range of biological activities. However, its poor water solubility and bioavailability are the foremost drawbacks that limit its application in therapeutics. The purpose of this investigation was to develop a natural nanoformulation made up of a biopolymer i.e. zein and sclareol in order to address this issue and to enhance the pharmacological efficacy of the drug. The sclarein nanoparticles (sclareol-loaded zein nanosystems) showed a typical monomodal pattern, characterized by a mean diameter of ~120 nm, a narrow size distribution and a surface charge of ~−30 mV. The evaluation of the entrapment efficiency and the drug-loading capacity of the nanosystems demonstrated the noteworthy ability of the protein matrix to hold sclareol while allowing a gradual release of the compound over time. The nanosystems increased the cytotoxicity of sclareol at a drug concentration of ≥5 μM with respect to the free compound after just 24 h incubation against various cancer cell lines. Indeed, the interaction of tritiated sclarein formulations with cells showed a time-dependent cell uptake of the nanosystems commencing as early as 1 h from the onset of incubation, favouring a significant decrease of the efficacious concentration of the drug.

Mulching has been extensively sought after in modern agriculture. However, massive utilization of plastics for mulching has induced severe environmental concerns. Developing biodegradable mulch thus represents an emerging need for future agriculture. By using bamboo-derived carboxymethyl cellulose (CMC), this study proposed a crosslinking strategy to prepare liquid film as quality mulch. CMC was synthesized by delignifying bamboo and etherifying resultant cellulose, which was then blended with polyvinyl alcohol (PVA) and crosslinked by glutaraldehyde to prepare a liquid film. By simply spraying on soil, mulch can quickly form on soil surface. Especially, bamboo-timber derived mulch had strong mechanical property (18.2 MPa), good transmittance (74.2%) and moisture absorption (141%), and excellent soil moisture retention. More importantly, about 64% of used mulches were biodegraded within 60-d after burring in soil, which will not need post-handling. These results highlighted that bamboo-derived mulch can be an alternative of current plastic mulch to tackle associated environmental pollution.

Two dual stimuli-activated photosensitizers were developed, in which two or three glutathione (GSH)-responsive 2,4-dinitrobenzenesulfonate (DNBS)-substituted zinc(II) phthalocyanine units were connected via one or two cathepsin B-cleavable Gly-Phe-Leu-Gly peptide linker(s). These dimeric and trimeric phthalocyanines were fully quenched in the native form due to the photoinduced electron transfer to the DNBS substituents and the self-quenching of the phthalocyanine units. In the presence of GSH and cathepsin B, or upon internalization into A549 and HepG2 cancer cells, these probes were activated through the release of free phthalocyanine units. The intracellular fluorescence intensity was increased upon post-incubation with GSH ester or reduced upon pre-treatment with a cathepsin B inhibitor. Upon light irradiation, these photosensitizers became highly cytotoxic with IC50 values of 0.21-0.39 μM. The photocytotoxicity was also dependent on the intracellular GSH and cathepsin B levels. The results showed that these conjugates could serve as smart photosensitizers for targeted photodynamic therapy.

15 p.-3 fig.-1 tab., Bacterial biopolymers such as bacterial cellulose (BC), alginate or polyhydroxyalkanotes (PHAs) have aroused the interest of researchers in many fields, for instance biomedicine and packaging, due to their being biodegradable, biocompatible and renewable. Their properties can easily be tuned by means of microbial biotechnology strategies combined with materials science. This provides them with highly diverse properties, conferring them non-native features. Herein we highlight the enormous structural diversity of these macromolecules, how are they produced, as well as their wide range of potential applications in our daily lives. The emergence of new technologies, such as synthetic biology, enables the creation of next-generation-advanced materials presenting smart functional properties, for example the ability to sense and respond to stimuli as well as the capacity for self-repair. All this has given rise to the recent emergence of biohybrid materials, in which a synthetic component is brought to life with living organisms. Two different subfields have recently garnered particular attention: hybrid living materials (HLMs), such as encapsulation or bioprinting, and engineered living materials (ELMs), in which the material is created bottom-up with the use of microbial biotechnology tools. Early studies showed the strong potential of alginate and PHAs as HLMs, whilst BC constituted the most currently promising material for the creation of ELMs., Research on polymer biotechnology at the lab of Auxi Prieto is supported by the European Union’s Horizon 2020 Research and Innovation Programme under grant agreements no. 745737 (Afterlife), no. 760994 (Engicoin),no. 870294 (Mix-Up), no. 814418 (SinFonia) and no. 101000733 (Promicon). At National level, the lab is supported by grants from the Community of Madrid (P2018/NMT4389), the Spanish Ministry of Science and Innovation under research grants BIOCIR (PID2020-112766RB-C21), REVOLUZION (PLEC2021-008188) and the Juan de la Cierva aid of Cristina Campano (FJC2019-040298-I).

Transforming potential waste materials into high-value-added sustainable materials with advanced properties is one of the key targets of the emerging green circular economy. Natural mica (muscovite) is abundant in the mining industry, which is commonly regarded as a byproduct and gangue mineral flowing to waste rock and mine tailings. Similarly, chitin is the second-most abundant biomass resource on Earth after cellulose, extracted as a byproduct from the exoskeleton of crustaceans, fungal mycelia, and mushroom wastes. In this study, exfoliated mica nanosheets were individualized using a mechanochemical process and incorporated into regenerated chitin matrix through an alkali dissolution system (KOH/urea) to result in a multifunctional, hybrid hydrogel, and film design. The hydrogels displayed a hierarchical and open nanoporous structure comprising an enhanced, load-bearing double-cross-linked polymeric chitin network strengthened by mica nanosheets possessing high stiffness after high-temperature curing, while the hybrid films (HFs) exhibited favorable UV-shielding properties, optical transparency, and dielectric properties. These hybrid designs derived from industrial residues pave the way toward sustainable applications for many future purposes, such as wearable devices and tissue engineering/drug delivery.

Canonical CRISPR–Cas systems provide adaptive immunity against mobile genetic elements1. However, type I-F, I-B and V-K systems have been adopted by Tn7-like transposons to direct RNA-guided transposon insertion2–7. Type V-K CRISPR-associated transposons rely on the pseudonuclease Cas12k, the transposase TnsB, the AAA+ ATPase TnsC and the zinc-finger protein TniQ7, but the molecular mechanism of RNA-directed DNA transposition has remained elusive. Here we report cryo-electron microscopic structures of a Cas12k-guide RNA–target DNA complex and a DNA-bound, polymeric TnsC filament from the CRISPR-associated transposon system of the photosynthetic cyanobacterium Scytonema hofmanni. The Cas12k complex structure reveals an intricate guide RNA architecture and critical interactions mediating RNA-guided target DNA recognition. TnsC helical filament assembly is ATP-dependent and accompanied by structural remodelling of the bound DNA duplex. In vivo transposition assays corroborate key features of the structures, and biochemical experiments show that TniQ restricts TnsC polymerization, while TnsB interacts directly with TnsC filaments to trigger their disassembly upon ATP hydrolysis. Together, these results suggest that RNA-directed target selection by Cas12k primes TnsC polymerization and DNA remodelling, generating a recruitment platform for TnsB to catalyse site-specific transposon insertion. Insights from this work will inform the development of CRISPR-associated transposons as programmable site-specific gene insertion tools. Structural studies on Scytonema hofmanni CRISPR-associated transposon protein complexes indicate a mechanism for RNA-guided DNA transposition involving Cas12k, TnsC and TnsB.

Bimetallic nanoparticles (BNPs) constitute two different metal elements and exhibit relatively superior mechanistic and catalytic efficacies owing to their synergistic functions over monometallic nanoparticles. In the present study various bimetallic Ag-Au, Ag-Pd, Au-Pd nanoparticles were synthesized using a natural biopolymer gum kondagogu (GK) as a reducing and capping agent, by a simple and cost-effective method. The synthesized BNPs when characterized using UV–vis spectroscopy revealed a specific surface plasmon resonance band (SPR) of each nanocomposite. The average particle size of Ag-Au, Ag-Pd, and Au-Pd BNPs was found to be 23 ± 10.3, 21 ± 7.6, and 23 ± 9.4 nm respectively based on transmission electron microscopy analysis. Surface morphology and functional groups on the gum matrix of GK-BNPs were analyzed by XRD and FT-IR respectively. The bimetallic nanocomposites were evaluated for their catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol in the presence of NaBH4. The kinetic studies performed, depicted rate constants for Ag-Au, Ag-Pd, and Au-PdNPs as 0.31, 0.39, and 0.28 min−1 respectively. The catalytic efficiencies of three bimetallic nanocomposites were of the following order Ag-Pd > Ag-Au > Au-Pd. This study establishes the catalytic potentials of the three different bimetallic nanocomposites in the reduction of 4-NP an environmental pollutant, and the impact of their synergistic property.

The cellular glycocalyx and extracellular matrix are rich in glycoproteins and proteoglycans that play essential physical and biochemical roles in all life. Synthetic mimics of these natural bottlebrush polymers have wide applications in biomedicine, yet preparation has been challenged by their high grafting and glycosylation densities. Using one-pot dual-catalysis polymerization of glycan-bearing α-amino acid N-carboxyanhydrides, we report grafting-from glycopolypeptide brushes. The materials are chemically and conformationally tunable where backbone and sidechain lengths were precisely altered, grafting density modulated up to 100%, and glycan density and identity tuned by monomer feed ratios. The glycobrushes are composed entirely of sugars and amino acids, are non-toxic to cells, and are degradable by natural proteases. Inspired by native lipid-anchored proteoglycans, cholesterol-modified glycobrushes were displayed on the surface of live human cells. Our materials overcome long-standing challenges in glycobrush polymer synthesis and offer new opportunities to examine glycan presentation and multivalency from chemically defined scaffolds., Synthetic mimics of glycoproteins and proteoglycans have wide applications in biomedicine, yet preparation has been challenged by their high grafting and glycosylation densities. Here the authors show one-pot dual-catalysis polymerization of glycan-bearing α-amino acid N-carboxyanhydrides to form glycopolypeptide brushes.

We demonstrate that cation condensation can induce the collapse of surface-bound nucleic acids and that the electrochemical signal from a tethered redox molecule (methylene blue) upon collapse reports on nucleic acid identity, structure, and flexibility. Furthermore, the correlation of the electrochemical signal and structure is consistent with theoretical considerations of nucleic acid collapse. Changes in solution dielectric permittivity or the concentration of trivalent cations cause the structure of nucleic acids to become more compact due to an increase in attractive electrostatic interactions between the charged biopolymer backbone and multivalent ions in the solution. Consequently, the compaction of nucleic acids results in a change in the dynamics and location of the terminally appended redox marker, which is reflected in the faradaic current measured using cyclic voltammetry. In comparison to ssDNA, nucleic acid duplexes (dsDNA, DNA/peptide nucleic acid, and dsRNA) require nucleic-acid-composition-specific solution conditions for the collapse to occur. Moreover, the magnitude of current increase observed after the collapse is different for each nucleic structure, and we find here that these changes are dictated by physical parameters of the nucleic acids including the axial charge spacing and the periodicity of the helix. The work here aims to provide quantitative and predicative measures of the effects of the nucleic acid structure on the electrochemical signal produced from distal-end appended redox markers. This architecture is commonly employed in functional nucleic acid sensors and a better understanding of structure-to-signal correlations will enable the rational design of sensitive sensing architectures.

Novel multifunctional biomimetic injectable hybrid systems were synthesized. The physicochemical as well as biological in vitro and in vivo tests demonstrated that they are promising candidates for bone tissue regeneration. The hybrids are composed of a biopolymeric collagen/chitosan/hyaluronic acid matrix and amine group-functionalized silica particles decorated with apatite to which the alendronate molecules were coordinated. The components of these systems were integrated and stabilized by cross-linking with genipin, a compound of natural origin. They can be precisely injected into the diseased tissue in the form of a viscous sol or a partially cross-linked hydrogel, where they can serve as scaffolds for locally controlled bone tissue regeneration/remodeling by supporting the osteoblast formation/proliferation and maintaining the optimal osteoclast level. These materials lack systemic toxicity. They can be particularly useful for the repair of small osteoporotic bone defects.

Due to their chemical composition, richness in calcium carbonate, chitin, proteins, and pigments, and nanoporous structure, crustacean shell waste shows great potential for a wide variety of applications. Large quantities of waste shells are produced annually, meaning that they can be considered a renewable source of ecofriendly biogenic materials, which can be turned into value-added byproducts. In this paper, an IR-based technique is developed to differentiate various biogenic powders originated from crude or food- processed crustacean shells. The validity of the method is supported by cross-checking with XRD, NMR, and SEM–EDX analyses. Our goal was to determine changes in properties of waste crab shells after the two most common treatments, deproteinization and milling. We discovered that deproteinization with NaOH could be tracked from the IR absorbance intensity ratio of the υ(CH2, 3) and υasym(CO32–) bands while milling time less influenced this ratio but induced changes in powder particle size distribution and morphology. The relative organic/inorganic ratio was different for different colored shells. Unexpectedly, waste shells stored for an average of 6 months or more were found to contain hydrated calcium carbonate (monohydrocalcite), which was absent in equivalent fresh shell composition. Deproteinization caused changes in mechanical properties of shells, making them more brittle, which resulted in a larger fraction of fine particles after powdering.

Methicillin-Resistant Staphylococcus aureus (MRSA) induced infection calls for antibacterial agents that are not prone to antimicrobial resistance. We prepare protease-resistant peptoid polymers with variable C-terminal functional groups using a ring-opening polymerization of N-substituted N-carboxyanhydrides (NNCA), which can provide peptoid polymers easily from the one-pot synthesis. We study the optimal polymer that displays effective activity against MRSA planktonic and persister cells, effective eradication of highly antibiotic-resistant MRSA biofilms, and potent anti-infectious performance in vivo using the wound infection model, the mouse keratitis model, and the mouse peritonitis model. Peptoid polymers show insusceptibility to antimicrobial resistance, which is a prominent merit of these antimicrobial agents. The low cost, convenient synthesis and structure diversity of peptoid polymers, the superior antimicrobial performance and therapeutic potential in treating MRSA infection altogether imply great potential of peptoid polymers as promising antibacterial agents in treating MRSA infection and alleviating antibiotic resistance., Antibiotic resistance is a major issue in medicine and new antimicrobials for treating resistant infection are needed. Here, the authors report on antibacterial peptoid polymers, prepared via NNCA ring-opening polymerization, demonstrating antibacterial function against MRSA in vitro and in in vivo infection models.

Phase transition is a promising aspect of DNA as biopolymers. Anionic DNA oligonucleotides easily form complexes with cationic polypeptides such as polylysine, and duplex formation significantly influences their complexation and resulting microcompartments. In this study, phase transition of microcompartments containing DNA and polylysine was systematically induced by modulating duplex formation of arylazopyrazole-conjugated oligonucleotides with light. We demonstrated that UV irradiation destabilized DNA duplex and generated isotropic coacervates, while duplex stabilization by visible light irradiation caused the formation of liquid crystalline coacervates. This photocontrol of phase transition was highly repeatable, and similar changes were observed even after ten cycles of light irradiation. Our approach would provide a robust control layer to the development of tailor-made microcompartments.

Fast pyrolysis of hydrolysis lignin was studied in fluidized bed units. Hydrolysis lignin, a bioproduct from the lignocellulosic ethanol production process (St1 Cellunolix), was processed in bench scale bubbling fluidized bed (BFB) and pilot scale circulating fluidized bed (CFB) units. Utilization of steam and ethanol as hydrogen sources was tested in a BFB unit. Major technical challenges identified were related to slow reaction rates of lignin degradation and the rapid secondary reactions in the vapor phase resulting in deposit formation and pressure buildup in product gas lines. The carbohydrate content of hydrolysis lignin had a clear correlation to its processability. More challenges with clogging and bed agglomeration were observed with lignin feedstock having lower carbohydrate content. The challenges with the bed agglomeration in the BFB unit were overcome by adding a rapidly rotating mixer in the reactor to break the agglomerates. With the CFB unit, bed agglomeration was not a problem, due to high gas velocities and forces applied to sand and lignin particles. In the BFB unit, the screw feeder was cooled and no significant melting problems were observed. In the CFB unit, melting problems were avoided by feeding the raw material in the cold section of reactor. However, severe increases in the pressure buildup and deposit formation rates were observed in both units. Steam and ethanol was tested, separately, in the BFB unit, to provide excess hydrogen in the system. Based on the product analyses both added hydrogen into the system, but hydrogen ended up mostly in the gas phase. To enhance the hydrogen transfer to the organic liquid, a catalyst active in hydrogen transfer is probably needed.

Polymers are essential materials in our daily life. The synthesis of value-added polymers is mainly performed from fossil fuel-derived monomers. However, the adoption of the circular economy model based on the bioeconomy will reduce the dependence on fossil fuels. In this context, biorefineries have emerged to convert biomass into bioenergy and produce high value-added products, including molecules that can be further used as building blocks for the synthesis of biopolymers and bioplastics. The achievement of catalytic systems able to polymerize the natural monomer counterparts, such as terpenes or terpenoids, is still a challenge in the development of polymers with good mechanical, thermal, and chemical properties. This review describes the most common types of bioplastics and biopolymers and focuses specifically on the polymerization of terpenes and terpenoids, which represent a source of promising monomers to create bio-based polymers and copolymers.

Disruption in the normal anatomy and physiology of the skin often leads to wound formation. Its healing is a pretty complex and dynamic biological process with different phases. While there are many biopolymers (and their derivatives) for wound healing purposes. One of the most popular, promising, progressive and attention-grabbing biopolymers is 'chitosan'. It is a polysaccharide biopolymer that has tremendous potential in augmenting the process of wound healing. Most importantly, the derivatives of chitosan have heavily attracted the scientific community's attention to employing them in various formulations for wound healing applications. The prime focus of the present review is to provide scientific and technological prospection about chitosan and its derivatives for wound healing activity, starting from 2010 to 2020. Besides, the review also focuses about toxicity, different formulations and products of chitosan that are currently under clinical trials for wound healing purposes are described. Through this review, we present evidence that abundantly confirms that there is a growing interest in the domain of wound healing using novel, inventive, useful and patent protected chitosan derivatives. We speculate the possibility of more patent protected chitosan derivatives in the future for wound healing applications.

The topochemistry of Japanese beech (Fagus crenata) wood delignification was evaluated in this study following a supercritical methanol treatment (270 °C, 27 MPa). Ultraviolet microscopic analysis of the insoluble residue revealed that the lignin in the secondary wall was easily decomposed and removed because of the preferential cleavage of ether-type linkages. In contrast, the middle lamella lignin was initially resistant to supercritical methanol but eventually decomposed and was removed. In addition, UV-absorbing secondary products formed selectively inside the parenchyma cells. Results from the supercritical methanol treatment of demineralized beech wood indicated that inorganic substances in the lumen of parenchyma affected the formation of these secondary products, thus leading to an overestimation of the residual lignin. Therefore, the topochemistry of delignification was more precisely evaluated when using demineralized beech wood.

3-Isopropylmalate dehydrogenase (IPMDH) catalyzes oxidative decarboxylation of (2R, 3S)-3-isopropylmalate to 2-oxoisocaproate in leucine biosynthesis. In this study, recombinant IPMDH (HjIPMDH) from an extremely halophilic archaeon, Haloarcula japonica TR-1, was characterized. Activity of HjIPMDH increased as KCl concentration increased, and the maximum activity was observed at 3.0 m KCl. Analytical ultracentrifugation revealed that HjIPMDH formed a homotetramer at high KCl concentrations, and it dissociated to a monomer at low KCl concentrations. Additionally, HjIPMDH was thermally stabilized by higher KCl concentrations. This is the first report on haloarchaeal IPMDH.

The present paper proposes a new strategy, based on the use of a new healthy animal diet additive obtained from urban biowaste, to reduce the environmental impact from livestock production. The diet supplement is a water soluble biopolymer (SB) obtained from urban gardening wastes. The paper reports the results of a case study in which 35 days old rabbits were fed a conventional diet as control and with a test diet made up of the conventional diet and 0.05–1% SB. Urine and faeces were collected, stored for 18 days at room temperature to simulate farm storage, and the resulting gaseous emissions were analysed. The manure from the animals fed the 0.25% SB diet produced significantly lowest emissions (p

Background The overall objective was to prepare a highly accurate nanocarrier system of mesalamine for the treatment of ulcerative colitis with increased therapeutic efficacy and targeting. In the formulation of nanocarrier systems, optimization is a critical process for understanding nanoformulation variables and quality aspects. The goal of the present work was to determine the effect of independent variables, i.e., the concentrations of chitosan, carboxymethyl inulin (CMI), and the drug on the response variables, i.e., particle size and percent entrapment efficiency of the mesalamine-loaded nanoparticle using the Box Behnken design (BBD). The correlation between the independent and dependent variables was investigated using the Design Expert generated mathematical equations, contour, and response surface designs. Result An optimized batch was developed using the ionotropic gel method with selected independent variables (A: + 1 level, B: 0 level, C: − 1 level) and the developed nanoparticles had a particle size of 184.18 nm, zeta potential 26.54 mV, and entrapment efficiency 88.58%. The observed responses were remarkably similar to the predicted values. The morphological studies revealed that the formulated nanoparticles were spherical, and the results of the FTIR and DSC studies indicated the drug-polymer compatibility. The nanoparticle showed less than 5% release in the pH 1.2. In the colonic region (pH 7.4), more than 80 % of the medication was released after 24 h. The kinetics study showed that the Higuchi and Korsemeyer-Peppas models had R2 values of 0.9426 and 0.9784 respectively, for the developed formulation indicating linearity, as revealed by the plots. This result justified the sustained release behavior of the formulation. Conclusion The mesalamine-loaded chitosan-CMI nanoparticle has been successfully developed using the ionotropic gelation method. The nanoparticles developed in this study were proposed to deliver the drug to its desired site. The developed nanoparticles were likely to have a small particle size with positive zeta potential and high percent drug entrapment. It could be stated from the results that BBD can be an active way for optimizing the formulation and that nanoparticles can be a potential carrier for delivering therapeutics to the colon.

Raising environmental awareness had forced researchers to explore the potential and implementation of environmentally friendly materials as alternatives for conventional materials. Environmentally friendly materials are biodegradable, safer, non-toxic, lightweight, cheap, and readily available. Arrowroot starch has a high content of amylose (~35.20%) which makes it suitable for better film production. Starch extracted from arrowroot rhizomes can be blended, plasticized with other polymers, or reinforced with fibres to improve their properties. The melt blended glycidyl methacrylate-grafted polylactide (PLA-g-GMA) and treated arrowroot fiber (TAF) treated with coupling agent developed PLA-g-GMA/TAF composite, which showed better properties than the PLA/AF composite. To the best of our knowledge, no comprehensive review paper was published on arrowroot fibres, starch biopolymer, and its biocomposites before. The present review focuses on recent works related to the properties of arrowroot fibres and starch, and their fabrication as biocomposites. The review also reveals the vast potential of arrowroot fibres and starch for food industries, medicines, textiles, biofuel, pulp, and paper-making industries, bioenergy, packaging, automotive, and many more.

Background. Wounds of various aetiology are among the most frequent traumatic injuries. A prospective route to improve treatment of this nosology is the development of novel or advancement of the already on-stage dressing materials.Objectives. A comparative experimental assay of novel chitosan-based wound dressings in the healing of soft tissue wounds of different genesis using ultrasound to control biodegradation of the developed dosage form.Methods. Soft tissue wounds were modelled in experimental animals, conventional and lineage male rats, 275 (± 25) g body weight, and male rabbits, 2,900 (± 150) g weight, using a proprietary methodology (Patent on invention RU No. 2703709 dated 23 August, 2018).Two wound dressing samples selected as most promising and applicable in large-volume soft tissue aseptic wounds were tested in the final step of experiment. Ultrasound imaging of the model wound area during the sample material biodegradation was used to control the wound process in more detail. At all steps of experiment, animal models were handled in compliance with GOST 33044-2014 “Principles of Good Laboratory Practice”.Histomorphological assays were carried out with common protocols. Variation statistics was used for the data analysis, including the mean (M) and standard mean error (± m) estimation. The level of statistical significance was p < 0.05.Results. The animal assays and comprehensive evaluation of the obtained data revealed a high healing efficacy of chitosan-based wound coatings. The analyses of wound dressing samples have confirmed their predesigned properties: scaffold stability, capillarity, biodegradability and matrix capacities for the carried drug delivery.Additionally, ultrasound was proved effective to estimate dynamics of the coated wound healing and biopolymer biodegradation processes.Conclusion. The developed chitosan-based wound dressings exhibited efficacy in an experimental model of the soft tissues wound process.The use of ultrasound to study dynamics of the wound process and coating biodegradation provided an adequate congruence between the imaging and tissue histomorphology data, as well as the structure and properties of coating material.

The potential for replacing the fossil-based Polyoxymethylene (POM) and Polyamide 66 (PA 66) in polymer gear applications with a bio-based Polyamide 6.10 (PA 6.10) was studied and is presented in the article. The use of bio-based plastics is increasing but mostly in undemanding applications like packaging. High-performance plastics are needed in polymer gear transmissions since their operational conditions are far more severe. The potential of bio-based PA 6.10 was studied by means of gear lifespan testing. Additional insights into the process of polymer gear meshing were garnered by simulating all the tested cases with a FEM model of meshing gears. Test gears were manufactured from commercially available materials, making the results useful for gear designers. Encouraging results were observed since the PA 6.10 gears exhibited a 3.5-times longer lifespan than POM gears and a 10-times longer lifespan than PA 66 gears when tested under identical test conditions. The results indicate great potential for replacing fossil-based plastics in polymer gear applications with bio-based polymer materials. The fatigue strength, coefficient of friction, and wear coefficient were determined and compared for the tested materials, facilitating the reliable design of polymer gears.

Background Polyunsaturated oils have various health-promoting effects, however, they are highly prone to oxidation. Encapsulation using biopolymers is one of the most effective strategies to enhance oil stability. This research examined the potential of gum arabic and maltodextrin for microencapsulation of omega-3 rich oils, aiming to enhance encapsulation efficiency and stability of encapsulated oil. Results We encapsulated fish and flaxseed oils by emulsification-spray drying. Spray-dried microcapsules were prepared by oil-in-water emulsions consisting of 10 wt% oil and 30 wt% biopolymer (gum arabic, maltodextrin, or their mixture). Results showed that both microcapsules were spherical in shape with surface shrinkage, and exhibited amorphous structures. Gum arabic-based microcapsules had higher encapsulation efficiency as well as better storage stability for both types of oil. Flaxseed oil microcapsules generally had higher oxidative stability regardless of the type of wall material. Conclusions Through a comprehensive characterization of the physical and chemical properties of the emulsions and resulting microcapsules, we proved gum arabic to be a more effective wall material for polyunsaturated oil microencapsulation, especially flaxseed oil. This study provides a promising approach to stabilize oils which are susceptible to deterioration, and facilitates their wider uses as food and nutraceutical products. This article is protected by copyright. All rights reserved.

openaire: EC/H2020/715788/EU//WoCaFi Funding Information: This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (Grant Agreement No 715788). Publisher Copyright: © 2021, The Author(s). Cellulose can be dissolved with another biopolymer in a protic ionic liquid and spun into a bicomponent hybrid cellulose fiber using the Ioncell® technology. Inside the hybrid fibers, the biopolymers are mixed at the nanoscale, and the second biopolymer provides the produced hybrid fiber new functional properties that can be fine-tuned by controlling its share in the fiber. In the present work, we present a fast and quantitative thermoanalytical method for the compositional analysis of man-made hybrid cellulose fibers by using thermogravimetric analysis (TGA) in combination with chemometrics. First, we incorporated 0–46 wt.% of lignin or chitosan in the hybrid fibers. Then, we analyzed their thermal decomposition behavior in a TGA device following a simple, one-hour thermal treatment protocol. With an analogy to spectroscopy, we show that the derivative thermogram can be used as a predictor in a multivariate regression model for determining the share of lignin or chitosan in the cellulose hybrid fibers. The method generated cross validation errors in the range 1.5–2.1 wt.% for lignin and chitosan. In addition, we discuss how the multivariate regression outperforms more common modeling methods such as those based on thermogram deconvolution or on linear superposition of reference thermograms. Moreover, we highlight the versatility of this thermoanalytical method—which could be applied to a wide range of composite materials, provided that their components can be thermally resolved—and illustrate it with an additional example on the measurement of polyester content in cellulose and polyester fiber blends. The method could predict the polyester content in the cellulose-polyester fiber blends with a cross validation error of 1.94 wt.% in the range of 0–100 wt.%. Finally, we give a list of recommendations on good experimental and modeling practices for the readers who want to extend the application of this thermoanalytical method to other composite materials.

Significance: Wound dressing based on naturally derived polymer provides a useful platform for treatment of skin injuries. Owing to the high mechanical strength and tunable structural and physicochemical properties of human elastin-like polypeptides (ELPs), they may be used as excellent materials for fabricating biocompatible scaffolds and other products for wound management. Recent Advances: Designing recombinant ELPs mimicking natural elastin to fabricate synthetic polymers suitable for human health care has generated significant interest. ELP-based cell-adhesive biopolymers have been used as an alternative for successful sutureless wound closure due to the physicochemical characteristics of the extracellular matrix. Critical Issues: Different systems of ELPs are being developed in the form of scaffolds, films, hydrogels, photo-linkable sheets, and composites linked with various types of growth factors for wound healing application. However, optimizing the quality and safety attributes for specific application needs designing of recombinant ELPs with structural and functional modifications as needed for the intervention. Future Direction: Chronic wounds are difficult to treat as the wound repair process is interrupted by conditions such as excessive inflammation, impaired extracellular matrix formation, and persistent infections. Conventional therapies such as skin substitutes or autologous skin grafts, in many cases, are unable to reestablish tissue homeostasis and proper healing. The development of innovative materials could induce a better regenerative healing response. In this study, we are reviewing different types of elastin-based materials for wound care application and their future prospects in regenerative medicine.

Although nanotechnology-driven drug delivery systems are relatively new, they are rapidly evolving since the nanomaterials are deployed as effective means of diagnosis and delivery of assorted therapeutic agents to targeted intracellular sites in a controlled release manner. Nanomedicine and nanoparticulate drug delivery systems are rapidly developing as they play crucial roles in the development of therapeutic strategies for various types of cancer and malignancy. Nevertheless, high costs, associated toxicity and production of complexities are some of the critical barriers for their applications. Green nanomedicines have continually been improved as one of the viable approaches towards tumor drug delivery, thus making a notable impact on which considerably affect cancer treatment. In this regard, the utilization of natural and renewable feedstocks as a starting point for the fabrication of nanosystems can considerably contribute to the development of green nanomedicines. Nanostructures and biopolymers derived from natural and biorenewable resources such as proteins, lipids, lignin, hyaluronic acid, starch, cellulose, gum, pectin, alginate, and chitosan play vital roles in the development of cancer nanotherapy, imaging and management. This review uncovers recent investigations on diverse nanoarchitectures fabricated from natural and renewable feedstocks for the controlled/sustained and targeted drug/gene delivery systems against cancers including an outlook on some of the scientific challenges and opportunities in this field. Various important natural biopolymers and nanomaterials for cancer nanotherapy are covered and the scientific challenges and opportunities in this field are reviewed.

Nature provides concepts and materials with interesting functionalities to be implemented in innovative and sustainable materials. In this review, it is illustrated how the combination of biological macromolecules, i.e. polydopamine and polysaccharides (cellulose, chitin/chitosan, alginate), enables to create functional materials with controlled properties. The mussel-adhesive properties rely on the secretion of proteins having 3,4-dihydroxyphenylalanine amino acid with catechol groups. Fundamental understanding on the biological functionality and interaction mechanisms of dopamine in the mussel foot plaque is presented in parallel with the development of synthetic analogues through extraction or chemical polymer synthesis. Subsequently, modification of cellulose, chitin/chitosan or alginate and their nanoscale structures with polydopamine is discussed for various technical applications, including bio- and nanocomposites, films, filtration or medical membranes, adhesives, aerogels, or hydrogels. The presence of polydopamine stretches far beyond surface adhesive properties, as it can be used as an intermediate to provide additional performance of hydrophobicity, self-healing, antimicrobial, photocatalytic, sensoric, adsorption, biocompatibility, conductivity, coloring or mechanical properties. The dopamine-based 'green' chemistry can be extended towards generalized catechol chemistry for modification of polysaccharides with tannic acid, caffeic acid or laccase-mediated catechol functionalization. Therefore, the modification of polysaccharides with polydopamine or catechol analogues provides a general platform for sustainable material functionalization.

Biopolymer based hydrogels are characteristic of their biocompatibility and capability of mimicking extracellular matrix structure to support cellular behavior. However, these hydrogels suffer from low mechanical properties, uncontrolled degradation, and insufficient osteogenic activity, which limits their applications in bone regeneration. In this study, we developed hybrid gelatin (Gel)/oxidized chondroitin sulfate (OCS) hydrogels that incorporated mesoporous bioactive glass nanoparticles (MBGNs) as bioactive fillers for bone regeneration. Gel-OCS hydrogels could be self-crosslinked in situ under physiological conditions in the presence of borax. The incorporation of MBGNs enhanced the crosslinking and accelerated the gelation. The gelation time decreased with increasing the concentration of MBGNs added. Incorporation of MBGNs in the hydrogels significantly improved the mechanical properties in terms of enhanced storage modulus and compressive strength. The injectability of the hydrogels was not significantly affected by the MBGN incorporation. Also, the proliferation and osteogenic differentiation of rat bone marrow mesenchymal stem cells in vitro and rat cranial defect restoration in vivo were significantly promoted by the hydrogels in the presence of MBGNs. The hybrid Gel-OCS/MBGN hydrogels show promising potential as injectable biomaterials or scaffolds for bone regeneration/repair applications given their tunable degradation and gelation behavior as well as favorable mechanical behavior and osteogenic activities., Graphical abstract Image 1, Highlights • In situ self-crosslinking of hybrid Gel-OCS/MBGN hydrogels. • Hybrid hydrogels are porous, injectable and bioadhesive. • Incorporation of MBGNs enhances mechanical and mineralization properties of hydrogels. • Osteogenic differentiation of BMSCs enhanced after incorporating MBGNs into hydrogels. • The presence of MBGNs enhances in vivo rat cranial defect restoration.

Egg white was precipitated with acetone and cross-linked with glutaraldehyde. Protease specificity of the polymer was investigated with different types of proteases and non-protease proteins. Protein polymer effectively bound trypsin, papain and the different proteases from pancreatin. SDS-PAGE results and diffusion agar plate tests supported the protease-binding efficiency of the polymer. in conclusion, egg white protein polymer can specifically bind proteases and it is a convenient and cost-effective material for enrichment, isolation, and removal of proteases., Ege University Scientific Research Projects Coordination (BAP)Ege University [2014FEN021], This research was supported by Ege University Scientific Research Projects Coordination (BAP) (Project number: 2014FEN021).

Modified biopolymer chitosan namely 2-hydroxy-1-naphthaldehyde chitosan (CTS-Nap) has been synthesized for the removal of toxic chromium from aqueous solutions. In an attempt to enhance the adsorption capacity of toxic chromium on the prepared modified biopolymer, magnetic Fe3O4 nanoparticles have been loaded on the modified adsorbent to form the magnetite adsorbent (Fe3O4@CTS-Nap). The adsorption mechanism of both adsorbents is explored by batch experiments, FT-IR, SEM, TEM, XRD, VSM, and EDS. The optimum adsorption is achieved at pH 1.5 for CTS-Nap and 1.0 for Fe3O4@CTS-Nap. Pseudo second order illustrated the best description for the adsorption process with correlation coefficient R2 = 0.999 and the film diffusion or chemisorption is the rate-limiting step. The equilibrium data is analyzed using five isotherm models, the experimental data agreed well with the Freundlich model with a maximum adsorption capacity of 78.12 mg g-1 and 57.14 mg g-1 for CTS-Nap and Fe3O4@CTS-Nap, respectively. However, this unexpected result revealed that the presence of magnetic nanoparticles does not always enhance the adsorption process and many other factors could control the adsorption process. Generally, these outcomes revealed that the unmagnetite modified adsorbent CTS-Nap have practical greater influence on wastewater treatment management rather than the magnetic modified chitosan Fe3O4@CTS-Nap.

Green chemistry or in other words “green world” is referred to a sustainable environment using biocompatible, biodegradable, renewable, economical, and simple materials, and methods. Without any exaggeration, the exceptional chemical and physical properties of ZnO bionanocomposites beside various utilizations, make it vital materials in research and green chemistry field. Biocompatible ZnO nanoparticles with fascinating antimicrobial, physicochemical, as well as photocatalytic performance could be applied as a prominent candidate to reinforce diverse biopolymer matrixes, for instance, chitosan, starch, cellulose, gelatin, alginate, poly(hydroxyalkanoates), carrageenan, and so on. With a combination of advantageous properties of these materials, they could be illustrated specific utilizations in different areas. In this regard, the following context focuses on highlighting the recent achievements of this category of material on three important and widely used scopes: eco-friendly food packaging, biomedical specially wound dressings, and water remediation technologies.

Novel Pickering emulsions were stabilized by complex interfaces in the presence of zein colloidal particles (ZCPs), propylene glycol alginate (PGA), and rhamnolipid (Rha) for delivery of β-carotene. The influence of the particle-surfactant, particle-biopolymer, and particle-biopolymer-surfactant mixed interfaces on the physiochemical properties and digestion fate of Pickering emulsions was investigated. It is the first time that three different types of emulsifiers have been used to synergistically stabilize food Pickering emulsions for delivery of lipophilic nutraceuticals. The physicochemical stability, microstructure, rheological properties, and in vitro gastrointestinal digestion of Pickering emulsions were controlled by the addition sequence and mass ratio of multiple stabilizers, which showed the enhanced stability and delayed lipid digestion of the particle-biopolymer-surfactant-stabilized Pickering emulsions. After encapsulation into Pickering emulsions, the retention rate of β-carotene increased 2-fold under UV radiation for 8 h. The coexistence of ZCPs, PGA, and Rha could induce the competitive displacement, multilayer deposition, and interparticle network at the interface. The combination of particles, a biopolymer, and a surfactant delayed the lipolysis during in vitro gastrointestinal tract. By modulating the interfacial composition, the release rate of free fatty acids from Pickering emulsions was reduced from 19.46% to 2.83% through different mechanisms. The novel Pickering emulsion could be incorporated in foods as well as pharmaceuticals for controlled lipid digestion or targeted nutrient delivery purposes.

The FtsZ protein is a central component of the bacterial cell division machinery. It polymerizes at mid-cell and recruits more than 30 proteins to assemble into a macromolecular complex to direct cell wall constriction. FtsZ polymers exhibit treadmilling dynamics, driving the processive movement of enzymes that synthesize septal peptidoglycan (sPG). Here, we combine theoretical modelling with single-molecule imaging of live bacterial cells to show that FtsZ’s treadmilling drives the directional movement of sPG enzymes via a Brownian ratchet mechanism. The processivity of the directional movement depends on the binding potential between FtsZ and the sPG enzyme, and on a balance between the enzyme’s diffusion and FtsZ’s treadmilling speed. We propose that this interplay may provide a mechanism to control the spatiotemporal distribution of active sPG enzymes, explaining the distinct roles of FtsZ treadmilling in modulating cell wall constriction rate observed in different bacteria., Bacterial protein FtsZ polymerizes at mid-cell and exhibits treadmilling dynamics, driving the movement of enzymes that synthesize septal peptidoglycan. Here, McCausland et al. combine theoretical modelling with single-molecule imaging of bacteria to show that FtsZ treadmilling drives enzyme movement via a Brownian ratchet mechanism.

Chitin, a polymer composed of β(1–4)‐linked N‐acetyl‐glucosamine monomers, and its partially deacetylated analogue chitosan, are abundant biopolymers with outstanding mechanical as well as elastic properties. Their degradation products, chitooligosaccharides (COS), can trigger the innate immune response in humans and plants. Both material and biological properties are dependent on polymer length, acetylation, as well as the pH. Without well‐defined samples, a complete molecular description of these factors is still missing. Automated glycan assembly (AGA) enabled rapid access to synthetic well‐defined COS. Chitin‐cellulose hybrid oligomers were prepared as important tools for a systematic structural analysis. Intramolecular interactions, identified by molecular dynamics simulations and NMR analysis, underscore the importance of the chitosan amino group for the stabilization of specific geometries., Automated glycan assembly was employed to prepare a collection of chitooligosaccharides with full control over length, fraction, and pattern of acetylation. Systematic structural studies, based on molecular dynamics simulations and NMR experiments, revealed intramolecular interactions responsible for the stabilization of particular conformations.

The remediation of methylene blue from wastewater using chitosan-sunflower-nano-iron (CSN) beds was examined in this study with the Fenton process. Nano-iron is synthesized using the green synthesis process. Then, biopolymer beds obtained nano-iron, sunflower tray waste, and chitosan. These beds used the Fenton process for removing Methylene blue (MB) from water. Beds synthesis and dye removing are characterized using SEM, TEM, FTIR, and XRD techniques. For the method optimization, the effects of dye concentration, temperature, pH, H2O2, and amount of biocatalyst were studied. The result of the wavelength scan was found 660 nm for methylene blue dye. Using CSN, catalyst was very effective in color removal for MB under optimal conditions. The highest removal rate 98% was obtained at pH 6 for 270 min. The optimum conditions for the MB dye are as follows; dye concentration: 25 mg/L, amount of absorbent: 2.5 mg/mL, temperature: 60 °C, H2O2 amount: 20 mg/L (600 µL, 30%). When the experiment is studied in optimum conditions, max. dye removal was calculated to be 98%. From SEM, TEM, XRD, and FTIR results, the change in the surface of the biocatalyst could be clearly observed. It is understood that the biocatalyst synthesized from the results we obtained easily removed a large amount of dye (MB).

In spite of the high electrical conductivity of carbon nanotube (CNT), its tendency to aggregate and expensive cost in fabricating aerogel, foams, and porous materials remains a problem. Therefore, we described a simple and feasible way to design light-weight, high electrically conductive, and cost-efficient polylactic acid (PLA)/CNT foams. The branched PLA (BPLA) resin with excellent melt elasticity and foamability was induced by nucleophilic ring-opening reaction of epoxy-based acrylic/styrene copolymer and PLA. After that, BPLA/CNT composites and foams were prepared by melt-mixing and supercritical carbon dioxide foaming technology, respectively. The thermal, electrical, and foaming properties were studied. The resultant BPLA/CNT foam possessed a low density of 0.174 g/cm3 and high crystallinity of 3.03%. An improvement of the oriented structure of CNT induced by cell growth in BPLA matrix increased the conductivity of the foam up to 3.51 × 104 Ω/m. The proposed foaming materials provided a way for designing and preparing high performance CNT products.

Background. Keratins are natural biopolymers with a wide range of applications in the field of biotechnology. Materials and Methods. Extraction of keratins was performed by a modified Nakamura method using 250 mM DTT. The protein concentration in the supernatant was determined by Bradford method. The protein composition was studied by their electro­phoretic separation in a polyacrylamide gel in the presence of sodium dodecyl sulfate. The films were made by casting. The surface characteristics of the films were determined using a scanning electron microscope REMMA-102. The elemental composition of the films was determined using an X-ray microanalyzer. Results . The protein concentration in the supernatant was 3.75 mg/mL. After using dithiothreitol in the extraction mixture, we obtained proteins of intermediate filaments with a molecular weight of 40–60 kDa and a low Sulfur content. In the low molecular weight region, we obtained keratin-associated proteins with a molecular weight of 10–30 kDa and a high content of Sulfur. These proteins belong to fibrillar proteins, which can be used as a matrix for the creation of new keratin-containing biocomposites with a wide range of applications in reparative medicine and tissue engineering. Based on the obtained keratin extract, polymer films with and without the addition of glycerol were made. Scanning electron microscopy revealed that glycerol provided the film structure with homogeneity and plasticity due to the accumulation of moisture after the fixation by water vapor. The X-ray microanalysis of films revealed such elements as Sodium, Silicon, Sulfur, Potassium. Among the detected elements, Sulfur has the largest share that is due to the large number of disulfide bonds in the keratin molecule. Conclusions. The polymer keratin films with the addition of glycerol demonstrated better mechanical properties and can be used in biomedicine. Keywords: keratins, hair, extraction, biopolymers Received 27 January, 2021 ● Revision 07 February, 2021 ● Accepted 17 March, 2021 ● Published 31 March, 2021

Objectives:The purpose of this study was to suggest a more efficient operation condition for the BAC(biological activated carbon) process by evaluating the change in the concentration of biopolymers in the effluent of the BAC process and the head loss of the BAC filter layer according to phosphate (PO4-P) and hydrogen peroxide (H2O2) input.Methods:During the experiment period (Feb. to Aug. 2020), the O3 dosage was fixed at 1 mg･O3/mg･DOC. Four columns with an inner diameter of 20 cm and a height of 250 cm were prepared. Empty bed contact time (EBCT) was fixed at 20 minutes and backwash was performed once a week. The four BAC columns are conventional BAC(control-BAC), enhanced BAC with hydrogen peroxide (H2O2+BAC), enhanced BAC with phosphate (PO4-P+BAC), and enhanced BAC with phosphate and hydrogen peroxide together (PO4-P+H2O2+BAC). In the case of enhanced BAC with PO4-P added, PO4-P was added with a concentration of 0.010 mg/L in the influent, and in BAC with H2O2, H2O2 was added with a concentration of 1 mg/L to the influent.Results and Discussion:According to the change of water temperature, the average head loss in control-BAC was 4.4 (25~28℃)~7.7 cm(8~12℃). In addition, PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC were 3.9~5.8 cm, 2.5~3.5 cm, and 2.6~3.5 cm, respectively. The head loss was reduced by the input of PO4-P and H2O2. During the low water temperature period, in control-BAC, the effluent biopolymers (BP) concentration was higher than the influent concentration, indicating that a large amount of EPS (extracellular polymeric substances) was produced and released from the attached biofilm. In PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC processes, the BP concentration ratio (Cout/Cin) was about 36~57% lower than that of the control-BAC during the low water temperature period. The BP concentration ratio was high when the water temperature (8~12℃) was low, and the BP concentration ratio gradually decreased as the water temperature increased. These results were very similar to those of the head loss change in the control-BAC process and the enhanced BAC process, and the BP concentration ratio and the head loss showed a very high correlation (r2=0.82~0.87). To evaluate the stability of the biofilm during the operation period, the total cell counts (TCC) in BAC treated waters were investigated. In control-BAC, PO4-P+BAC, H2O2+BAC and PO4-P+H2O2+BAC process, the average TCC was 46.8×106 cells, 30.3×106 cells, 21.8×106 cells, and 18.8×106 cells, respectively. Compared to the control-BAC, it was found to be 35~60% lower in the enhanced BAC processes. In addition, live cell count (LCC) ratio (LCC/TCC) was 0.84~0.89 in the enhanced BAC processes compared to 0.53 in the control-BAC. These results indicate that the biofilm stability of the enhanced BAC processes is higher than that of control-BAC.Conclusions:During the experiment, compared to the conventional BAC process, the enhanced BAC processes in which PO4-P and H2O2 were added showed a clear effect of reducing the head loss. In particular, the effect of reducing the head loss was higher when H2O2 was added than when PO4-P was added. A rapid head loss increase occurred in the conventional BAC process compared to the enhanced BAC processes in the low water temperature season is the result of the production of large amounts of EPS in the attached biofilm. The input of PO4-P or H2O2 reduces the head loss by improving the stability of the attached biofilm and reducing EPS production.

Natural polysaccharides have been investigated as vehicles for oral insulin administration. Because of their non-toxic, renewable, low cost and readily available properties, gums find multiple applications in the pharmaceutical industry. This work aimed to develop a Sterculia striata gum-based formulation associated with additional biopolymers (dextran sulfate, chitosan, and albumin), a crosslinking agent (calcium chloride) and stabilizing agents (polyethylene glycol and poloxamer 188), to increase the oral bioavailability of proteins. Insulin was used as a model drug and the methods used to prepare the formulation were based on ionotropic pregelation followed by electrolytic complexation of oppositely charged biopolymers under controlled pH conditions. The developed formulation was characterized to validate its efficacy, by the determination of its average particle size (622 nm), the insulin encapsulation efficiency (70%), stability in storage for 30 days, and the in vitro mucoadhesion strength (92.46 mN). Additionally, the developed formulation preserved about 64% of initial insulin dose in a simulated gastric medium. This study proposed, for the first time, a Sterculia striata gum-based insulin delivery system with potential for the oral administration of protein drugs, being considered a valid alternative for efficient delivery of those drugs.

Chitosan, collagen, gelatin, polylactic acid and polyhydroxyalkanoates are notable examples of biopolymers, which are essentially bio-derived polymers produced by living cells. With the right techniques, these biological macromolecules can be exploited for nanotechnological advents, including for the fabrication of nanocarriers. In the world of nanotechnology, it is highly essential (and optimal) for nanocarriers to be biocompatible, biodegradable and non-toxic for safe in vivo applications, including for drug delivery, cancer immunotherapy, tissue engineering, gene delivery, photodynamic therapy and many more. The recent advancements in understanding nanotechnology and the physicochemical properties of biopolymers allows us to modify biological macromolecules and use them in a multitude of fields, most notably for clinical and therapeutic applications. By utilizing chitosan, collagen, gelatin, polylactic acid, polyhydroxyalkanoates and various other biopolymers as synthesis ingredients, the 'optimal' properties of a nanocarrier can easily be attained. With emphasis on the aforementioned biological macromolecules, this review presents the various biopolymers utilized for nanocarrier synthesis along with their specific synthetization methods. We further discussed on the characterization techniques and related applications for the synthesized nanocarriers.

The aim of the present work was to evaluate the performance of polypropylene (PP)/sisal fiber (SF)/banana fiber (BF) and chitosan-based hybrid (chitosan(CS)/SF)/BF) composite materials for the adsorptive removal of cadmium (Cd) ions from water waste. Polypropylene is harnessed for its importance in forming strong composite materials for various applications. Chitosan biopolymer encloses a great deal of amino and hydroxyl groups, which provide effective removal of Cd ions from wastewater. The batch adsorption studies proved that the removal of Cd ions was pH-dependent and attained optimum at pH 5.5 for both the composites. Langmuir and Freundlich models were applied for the obtained experimental values. Based on the R2 values, it was evidenced that the adsorption process was best fitted with the Freundlich isotherm than Langmuir. The sorption capacity of CS/SF/BF hybrid composite (Cmax = 419 mg/g) is higher than PP/SF/BF composite (Cmax = 304 mg/g), and allows multilayer adsorption. Kinetics studies revealed that the pseudo-second-order model was followed during the removal of Cd ion from wastewater. The overall evaluation proved that though both the adsorbents are suitable for the removal of Cd ions, the efficiency of CS-based ternary composite material is better than PP-based composite.

A facile and greener methodology to obtain pure chitosan-based 3D porous structures in the form of monoliths and films is proposed. It is based on a modified evaporation-induced phase separation process in a chitosan solution precursor. In this approach, a deep eutectic solvent (DES) is used as the nonsolvent system and an ecofriendly, cost effective, simple and versatile alternative for the production of highly structured chitosan materials. The porous heterogeneous structure can be fine-tuned by varying the chitosan content in the precursor solution and chitosan/DES ratio, and enabled the structured polymer to absorb large amounts of water to form hydrogels. This is a versatile and unexplored approach to design porous chitosan with tailored morphology in the absence of crosslinkers, which, based on preliminary studies on V. cholerae biofilm formation, is expected to open new avenues for various applications in biomedical, catalysis, water purification, filtration and other areas where the control of bacterial biofilm formation is critical.

Existing therapies yield low drug encapsulation or accumulation in the lungs, hence the site-specific drug delivery remains the challenge for tuberculosis. Lately, dry powder inhalers (DPIs) are showing promising drug deposition in the deeper lung tissues. Biocompatible polymers with the ability to naturally recognize and bind to the surface receptors of alveolar macrophages, the reservoir of the causative organism, were selected. DPIs comprised of chitosan (CS)/thiolated chitosan (TC) in conjugation with Hyaluronic acid (HA) were synthesized loaded with isoniazid (INH) by using the Design of Experiment (DoE) approach. Nanosuspensions were prepared by ionic gelation method using cross-linker, sodium-tripolyphosphate (TPP) and were optimized by using Box-Behnken 3-level screening design and later freeze-dried to obtain nanopowders. Physico-chemical compatibility of nanoplex systems was investigated using in-vitro characterization techniques. In-vitro release and permeation studies were correlated in terms of the pattern of drug content dissolved over time. In addition, the cytotoxicity studies on A549 cells demonstrated the safety profile of the nanoplexes. Moreover, in-silico studies and aerodynamic profiles verify the suitability of DPIs for further in-vivo tuberculosis therapeutics. DoE analyses affirmed the lack of linearity in the model for the certain response of studied parameters in a holistic way, which was not possible else ways.