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Fungal keratitis is estimated to have at least 1 million incidences and causes 100,000 eye removal globally annually. Hourly eye drop administration remains the standard of care, and however, its low bioavailability and low patient compliance often lead to poor patient outcomes. My work is a response to the call for the urgent unmet need for an alternative drug delivery platform to combat ocular infection. In my dissertation, I utilized two composite systems for the antifungal contact lens: mesoporous silica nanoparticle (MSN) embedded chitosan and poly(lactic-co-glycolic acid) (PLGA) embedded poly(2-hydroxyethyl methacrylate) (pHEMA). For the MSN-chitosan system, I explored the loading methods and conditions to incorporate antifungal drugs into MSNs, characterized drug release profile and materials properties, verified fungal killing efficacy against Fusarium and Aspergillus to evaluate its potential as an antifungal contact lens material. For the PLGA-pHEMA system, I converted a planar structure prototype into a convex lens. I described the adjustment of lens fabrication process for precise geometry control, lens design iteration for improvement of drug release, and verification of the antifungal performance of the convex lens. This work provides insights of drug loading and delivery of highly insoluble drug and examples on contact lens fabrication process design with precise control on the laboratory scale.

This study analyses the effectiveness of the biopolymer xanthan gum (XG) to improve the mechanical properties of silty sand. The study focuses on the effects of the curing time and the content of XG on the unconfined and confined behaviour of soil treated with this biopolymer. The study was carried out with specimens cured under high-humidity conditions, through the comparison of the unconfined compressive strength (UCS), stiffness, compressibility and vertical yield stress of non-stabilised and biostabilised specimens, obtained from UCS and oedometer tests. Additionally, the pH value and results of scanning electron microscopy (SEM)/ energy-dispersive X-ray analysis (EDX) tests are presented and discussed. The biostabilisation of this soil with XG induces a more ductile stress–strain behaviour, a moderate increase in UCS and stiffness, and in the increase of the one-dimensional compressibility, with a greater effect for higher XG contents. The SEM/EDX tests show that the biopolymer induces a random biopolymer network in the biostabilised specimens that is related to the strengthening obtained.

Chitosan (CS) is a natural and biopolymer that are suitable biomedical properties such as; biocompatibility, non-toxicity, biodegradability and bioactive polymer that’s reason with a very large application (fabrication of biomedical scaffolds, implants). Some of the biocompatible thermoplastic polymers (PLA, PEEK, PLGA, PE, PP, PMMA, PET and etc.) are most widely used in biomedical field as per their properties from last two decades. Poly-vinyl chloride (PVC) thermoplastic polymer are most widely used in medical field but there are some limitations of their uses. For enhancement of PVC thermoplastic polymers properties sometimes add some bioactive and biocompatible fillers or other bioactive thermoplastic polymers. In this review paper try to link and discussed about the possible reinforcement CS in PVC thermoplastic polymer for biomedical applications.

Biopolymer electrolytes based on iota-carrageenan (I-carrageenan) with sodium trifluoromethanesulfonate (NaTf) were prepared by way of the conventional solution-casting technique. The biopolymer I-carrageenan was fixed as 1 g, and the concentration of NaTf was varied from 0.1 to 0.5 wt% in steps of 0.1 wt%. Distilled water was used as a solvent. Alternating current (AC) impedance measurements were carried out in the frequency window of 42 Hz–1 MHz. The same measurements were also carried out at different temperatures for all the prepared biopolymer samples. A maximum ionic conductivity of 2.6771 × 10−5 S/cm was obtained for the 0.3 wt% NaTf-added I-carrageenan system at room temperature. The temperature-dependent conductivity plot of the polymer electrolyte seemed to obey the Arrhenius relation. A low activation energy of 0.021 eV was observed for the sample with the highest ionic conductivity. From AC impedance data, dielectric parameters were obtained. The magnitude of the dielectric constant was found to increase with the increase in temperature. A low relaxation time was observed for the sample that possesses the maximum ionic conductivity.

The biopolymer hyaluronic acid (HA) is ubiquitous in extracellular spaces and forms complexes with proteins and proteoglycans that contribute to tissue mechanical properties, provide lubrication at biointerfaces, and affect cell adhesion and motility. It is not well-understood how structural features within single HA chains control its biological roles and its potential for use in biomaterials. HA's structural length scales (persistence length, charge spacing) are intermediate relative to other biopolymers; this makes it a useful model system for studying polyelectrolyte physics. We use magnetic tweezers to investigate how salt and HA-binding ligands can modify its random coil structure.We present data on HA's behavior in mixed valence salt solutions, and find a regime of conformational insensitivity to ionic strength. Experiments on another flexible charged biopolymer, single-stranded DNA, confirm the effect is a general electrostatic phenomenon. With simulations and theory, we build a picture of how ion exchange within a counterion-rich layer near the chain counteracts changes in the bulk ionic strength. We also use magnetic tweezers to measure changes in HA structure associated with the formation of HA-proteoglycan bottlebrush complexes. As the large proteoglycan aggrecan binds, it induces tension in the central HA chain. Using established bottlebrush theory, we connect this tension to structural features of aggrecan. Overall, we find magnetic tweezers are sensitive to HA's random coil structure and its modification by solute interactions.

An interest in searching for a light, compact, and longer life cycle of energy storage devices among researchers has been increasing over the years, leading to the development of polymer electrolytes (PEs), which is a powerful platform due to their unique properties. PEs have been successfully developed into various types, i.e., solid, gel, and composite. As the researchers have zeroed in on finding new trades to use conventional synthetic polymer electrolytes to address environmental contamination concerns, biodegradable polymers or bio-polymers can be assumed to be an essential part of various other options. It has been found that these bio-polymers can be viably utilized as a polymer host in the preparation of the electrolyte framework. Various possible applications have been made using bio-polymer electrolytes (BEs), especially in energy storage devices, such as supercapacitors, batteries, fuel cells, and solar cells, as described in this review. The present review article also consists of a glimpse of the challenges in developing bio-polymers in the application of electrolyte systems.

Hydrogels have a wide range of applications in tissue engineering, drug delivery, device fabrication for biological studies and stretchable electronics. For biomedical applications, natural polymeric hydrogels have general advantages such as biodegradability and non-toxic by products as well as biocompatibility. However, applications of nature derived hydrogels have been severely limited by their poor mechanical properties. For example, most of the protein derived hydrogels do not exhibit high stretchability like methacrylated gelatin hydrogel has ∼11% failure strain when stretched. Moreover, protein derived elastomeric hydrogels that are fabricated from low molecular weight synthetic peptides require a laborious process of synthesis and purification. Biopolymers like gelatin, produced in bulk for pharma and the food industry can provide an alternative for the development of elastomeric hydrogels. Here, we report the synthesis of ureidopyrimidinone (Upy) functionalized gelatin and its fabrication into soft elastomeric hydrogels through supramolecular interactions that could exhibit high failure strain (318.73 ± 44.35%). The hydrogels were fabricated through a novel method involving co-solvent optimization and structural transformation with 70% water content. It is anticipated that the hydrogel fabrication method involves the formation of hydrophobic cores of ureidopyrimidinone groups inside the hydrogel which introduced elastomeric properties to the resulting hydrogel. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) Nanyang Technological University Published version The authors acknowledge the financial support provided by Ministry of Education, Singapore, Singapore Centre for 3D Printing (SC3DP), A*STAR (Singapore Food Story R&D Programme), and School of Material Sciences and Engineering, Nanyang Technological University, Singapore.

Bioactive ions (Mg, Sr, Zn) doped carbonated hydroxyapatite powders (dHAp) and pure carbonated hydroxyapatite (HAp) powders were prepared by wet chemical precipitation method. The bioactive ions were incorporated into the HAp matrix by co-precipitation from solution containing the appropriate amount of chloride salt of different ions. The morphology of pure HAp was mainly needle-like in nanometre size and the particles were disordered showing quasi-amorphous structure. The ion doping changed the morphology of particles, the dHAp particles had distorted spheroid shapes. Owing to the ion addition, the crystallinity of particles decreased. Particle aggregations can also be observed in both types of samples. HAp and dHAp loaded biopolymer polyvinylpyrrolidone (PVP) composite materials have also been developed by novel electrospinning technique. It has been shown that both the HAp and dHAp particles can be successfully incorporated into the PVP fibre web matrix and simultaneously the bioceramic powders were attached to the surface of polymer fibres. The surface of fibres was not fully covered with the particles. The ceramic powder addition to the polymer solution caused the polymer fibres to become more entangled and the diameters of fibres varied over a wider range compared to the base polymer fibres without bioceramic powder addition.

Dry powder products are highly sensitive to oxygen and water vapour and must have a long shelf life. Currently, they are vacuum-packaged in sachets whose walls are made of a composite film that stops oxygen and water vapour from entering the package. Most of these composites are not biodegradable, a situation that the most agricultural company now wants to change to gain in sustainability. According to National Geography (2019), every year, about 8 million tons of plastic waste escapes into the oceans from coastal nations, with some estimates ranging to at least 400 years to break down. Over the years, there is huge interest in the development and use of biobased packaging materials, however, most of these materials are brittle and have low mechanical properties. Thus, in order to overcome these drawbacks, blended polymers with the reinforcement of nanocellulose are recommended. The aim of this paper is to review packaging films with oxygen barrier properties similar to those of the conventional films but also having biodegradable properties. From the literature, the oxygen permeability coefficient improved with the high strength, modulus, and ductility, as the nanocellulose was reinforcing with biopolymer. This might be due to nanocellulose that contributes to the higher stretchability of the composite biofilms. A fine dispersion of nanocellulose throughout the polymer host promoted several improved properties of the composite biofilms. In addition, nanocellulose had greatly enhanced oxygen and water vapour barrier properties. It would indeed push the usability of biopolymers forward, and certainly, prompt wider application of biodegradable polymers in the fields of environmental protection such as biodegradable food packaging.

In the present work, alginate (Alg) blend with polyvinyl alcohol (PVA) with various compositions was prepared by using solution casting method. The intermolecular interaction occurred in the polymer blends were investigated via Fourier Transform Infrared (FTIR) spectroscopy. Electrical impedance spectroscopy was used to determine the conductivity values of the blends. The conductivity value of Alg-PVA polymer blend was found to be optimum at (7.52 ± 0.04) × 10−8 S/cm for composition with 70:30 of Alg:PVA. Based on the findings, it is believed that the Alg-PVA blend is a promising candidate to be act as polymer host materials for application in polymer electrolyte system.

A lithium ion conducting solid biopolymer membrane (SBE) has been prepared by incorporating lithium chloride salt (LiCl) with the biopolymer K- Carrageenan (Kappa Carrageenan) using solution casting technique. One gram Kappa Carrageenan with 0.5 g LiCl yields ionic conductivity value of 1.15 × 10-2 Scm−1 which has been found by using Ac impedance analysis. The highest conducting biopolymer membrane possesses high amorphous nature among all the prepared biopolymer membranes, and XRD analysis confirms it. Highest conducting biopolymer possesses low crystallinity percentage of 8.18. Transference number analysis by Wagner’s polarization technique provides information that the major contribution for the conductivity is given by ions whereas minor contribution has been given by electrons. Transference number of ions is found to be 0.96 whereas transference number of electrons is 0.04. By using the using highest conducting composition (one gram Kappa Carrageenan: 0.5 g LiCl) as electrolyte, LiFePO4 as cathode and activated charcoal/graphite as anode, rechargeable lithium-ion conducting battery has been constructed and its voltage is found as 3.25 V. The performance of the battery has been studied by connecting a load (100 kΩ).

The huge packaging application of non-degradable plastics has created a severe threat to the present civilization. This work emphasizes on low density polyethylene/corn starch biopolymer sheets production. Biodegradability assessment was done under alkali, acid, compost pit soil, garden soil and vegetable waste environment for one year. Enhancement in starch content by 60% in the matrix improved the Young’s modulus and stiffness from 251.79−422.42 MPa and 17763.34–27481.87 N/m respectively. Highest increase in weight loss percent from 1.26% for virgin LDPE to 13.18% for the sample LC5 (LDPE-16 g, Starch-24 g) was observed in garden soil. The degradation was also reported by morphological non-uniformness (SEM images) and drop in mechanical properties like tensile strength from 7.9 to 2.12 MPa in vegetable waste environment. Increase in haze from 97.20 to 99.8% and decrease in transmittance from 68.40 to 28.20% in vegetable waste for sample LC5 confirmed the optical degradability of the sheets.

This paper reports the physical properties of magnesium ion (Mg2+) conducting biopolymer electrolyte films of cellulose acetate (CA) + xwt.% Mg(ClO4)2 containing different amounts of magnesium salt (x = 10, 20, 30, 40 and 50 wt%) which have been prepared by the solution cast technique. The prepared biopolymer films were characterised by XRD, FTIR, DSC and UV–vis spectroscopy. The structural analysis carried out by X-ray diffraction (XRD) study confirms the structural changes & decrease in the degree of crystallinity of the host biopolymer matrix CA upon incorporation of magnesium salts Mg(ClO4)2. And this effect is more pronounced at higher loading. The DSC thermograms of the electrolyte films showed that the glass transition temperature (Tg) increases with the increase of salt content in the biopolymer CA matrix which is attributed to the restriction in the mobility of the polymeric chains. This hindrance was caused by the high density constituent ions of dopant salt. Fourier transform infrared (FTIR) spectroscopic study confirms the complexation between the cations of the dopant salt (Mg2+) and ester group (i.e. C = O) of the biopolymer chain owing to Lewis acid-base interactions. The UV–visible spectroscopic analysis demonstreted that optical absorption edge as well as direct & indirect optical band gap decreases with the incease of the concentration of dopant magnesium salt.

Controlling oriented crystallization is key to producing bonelike composite materials with a well-organized structure. However, producing this type of composite material using synthetic biopolymers as scaffolds is challenging. Inspired by the molecular structure of collagen-I, a collagenlike peptide─(Pro-Hyp-Gly)10 (POG10)─was designed to produce self-assembled fibrils that resemble the structure of collagen-I fibrils. In addition, the oriented mineralization of HAP crystals is formed in the fibrils that reproduces a bonelike material similar to collagen-I fibril mineralization. Unlike collagen-I fibrils, POG10 fibrils do not contain gap spaces. The molecular simulation results indicate that in addition to space confinement, the molecular field generated by POG10 can also confine the orientation of HAP, enriching our understanding of physical confinement and shedding light on the design of synthetic biopolymer scaffolds for bonelike material fabrication.

Owed to current environmental concerns and crude oil price fluctuations, the design of feasible substitutes to petroleum-based polymeric materials is a major challenge. A lot of effort has been focused on transforming natural vegetable oils (VOs), which are inexpensive, abundant, and sustainable, into polymeric materials. Different nanofillers have been combined with these bio-based polymer matrices to improve their thermal, mechanical, and antibacterial properties. The development of multifunctional nanocomposites materials facilitates their application in novel areas such as sensors, medical devices, coatings, paints, adhesives, food packaging, and other industrial appliances. In this work, a brief description of current literature on polymeric nanocomposites from vegetable oils reinforced with carbon nanomaterials is provided, in terms of preparation, and properties. Different strategies to improve the nanomaterial state of dispersion within the biopolymer matrix are discussed, and a correlation between structure and properties is given. In particular, the mechanical, thermal, and electrical properties of these natural polymers can be considerably enhanced through the addition of small quantities of single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphene (G), or its derivatives such as graphene oxide (GO) or fullerenes (C60). Finally, some current and potential future applications of these materials in diverse fields are briefly discussed.

Hydrogels, including PVA hydrogels, have numerous applications in many fields; however, their poor mechanical strength limits their utilization potential. Lignin, the most abundant aromatic biopolymer in nature from lignocellulosic biomass, is presently under-utilized. Herein, we used lignin to improve strength and impart pH-responsive properties of PVA hydrogel. The lignin reinforced PVA (LRP) hydrogel has a maximum storage modulus of 83.1 kPa, which is much higher than the PVA hydrogel. The LRP hydrogel exhibits great ionic conductivity, mechanical properties, and strain-sensitivity even at −30 °C. The LRP hydrogel is subsequently applied for a moisture-induced electric generator, which delivers a voltage output of 226.6 mV from moisture flow. The eco-friendly, pH responsive, high antifreezing, ionic conductive, strain sensitive, and moist-electric generating hydrogels have potential applications in many fields, including biomedicine, flexible electrodes, pH-responsive switch, strain sensor, and next-generation self-powered device systems.

Supercapacitors have received a great attention owing to their exceptional characteristics like outstanding cycle life, high power and eco-friendly nature. In recent years, chitin/chitosan derived porous carbon electrode materials for energy storage applications have gained a substantial consideration due to their broad accessibility, high porosity, less weight, natural biodegradability, renewability, and eco-friendly. More importantly, chitin/chitosan biopolymers have a linear long chain-like moiety attached to functionalize the surface groups with -β-D glucosidic linkage which can be exploited as templates for constructing electrode materials with tunable and well-definite geometrics. The main focus was on porous carbon derived from heteroatoms doped chitin/chitosan biopolymers along with their composites in supercapacitor applications. In addition, the overall behaviors in supercapacitor application have been discussed in terms of specific capacitance, specific surface area, voltage window, energy density, and power density. Furthermore, the present review addresses the up-to-date development accomplished in chitin/chitosan materials for supercapacitor electrodes. Eventually, the recent challenges and forthcoming perspectives of the chitin/chitosan biopolymer derived porous carbon electrode materials with respect to the supercapacitor’s performance were thoroughly tinted along with future energy storage devices, such as fuel cell, solar cells and lithium ion battery.

Gelatin is a natural and environment-friendly polymer that can be cross-linked to various degrees with glutaraldehyde (GTA) and swollen with water to form a hydrogel. As the gelatin cross-link density increases, gel stiffness increases and swelling in water decreases with the cross-link density saturating at about 0.01 mol of GTA. Forming gelatin hydrogel bilayers with layers of differing cross-link densities results in a gelatin actuator that bends toward the layer of higher cross-link density when swollen in water. The extent of bilayer bending is dependent on the difference between the volume swelling ratio of the layers, which is directly determined by the cross-link density difference. When the gelatin bilayers are close in swell ratio or when the swell ratios are significantly different, no bending occurs. The highest bending is found when the higher cross-linked passive layer swells to about 60% of the swelling of the lower cross-linked active layer. Filling the active layer with pre-gelatinized starch increases the bilayer curvature, but it returns to its original shape after hydrolyzing the starch with α-amylase, demonstrating shape change in response to a biochemical reaction. The results show that simple gelatin bilayers can serve as actuators when stimulated with water or sugar and enzyme.

Background: Composite materials make it possible to modulate the properties of the source materials and expand their technological potential. In this sense, composite materials made from solid biopolymeric electrolytes and graphene oxide can be an attractive alternative for applications in organic electronics due to their electrochemical properties. Aim: The present work aims to evaluate the electrochemical behavior of a composite material made of solid biopolymeric electrolyte of cassava starch and graphene oxide at different concentrations to determine the effect of this concentration and the pH used in the production process. Methods: The composite material was made from the use of cassava starch plasticized with glycerol, glutaraldehyde, polyethylene glycol and with lithium perchlorate as electrolytes. During the synthesis process, graphene oxide was added in different concentrations (0, 0.25, 0.50, 1.00, 1.25, 1.50, and 1.75 %w/w) to evaluate the effect of the concentration of this component. The synthesis was carried out by thermochemical method with constant heating in an oven at 75 ° C for 48 hours. Films were prepared using synthesis solutions at different pH (5.0 and 9.0). The pH was regulated by adding HCl or NaOH to the synthesis solution as appropriate. Results and Discussion: The results showed that the cassava starch biopolymeric solid electrolyte films without plasticizers were stiff and brittle, so they broke easily. The films with plasticizers and the films of the composite material were stable to the manual traction, allowing their easy manipulation without breaking. The films presented a similar electrochemical behavior in terms of oxide reduction processes; however, the films with graphene oxide presented signals with higher peak currents. Films made at pH 9.0 showed 50 % more intensity in peak currents. The addition of graphene oxide affected the current parameters and peak potentials, being more marked in the films prepared at pH 9.0; at this pH the films with concentrations of graphene oxide lower than 1.00 %w/w presented variable Ep and Ip, while at concentrations of graphene oxide greater than 1%w/w, the behavior did not show significant variations. Conclusions: The addition of graphene oxide modulates or modifies the electrochemical behavior of cassava starch biopolymeric solid electrolyte films, and the processing pH can vary the effect of the graphene oxide addition.

The aim of this research was to identify a biopolymer producing potential actinobacteria candidate from polluted soil. The Streptomyces toxytricini D2 was enumerated as potential biopolymer producer, which was isolated and characterized using 16S rRNA sequencing. The S. toxytricini D2 produced polymeric granules were categorized through FTIR, 1H NMR, and 13C NMR analyses, which confirmed that the granules were Polyhydroxyalkanoates (PHAs). The S. toxytricini D2 has the competence to produce 86.56% of PHAs (23.64 g L−1 of PHAs from 27.31 g L−1 of biomass) under optimized growth conditions: 8% of tapioca molasses, 4% of (NH4)2SO4, 8% of inoculum, pH 6.5, 30 °C and 72 h of incubation. These findings concluded that S. toxytricini D2 could be used as an efficient candidate for the mass production of PHAs polymer under optimized conditions, with a low-cost carbon source and in a short time of production period.

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.

Conventional soil additives, as a sector of construction materials, can cause serious environmental problems due to their cement-dependent nature. To eliminate destroying effects of these kinds of additives, environmentally friendly ones have gained great consideration. Although polysaccharides are considered as powerful biocompatible soil additives in recent studies, the effect of their crosslinked hydrogel with elevated rheological and adhesive properties has been very rarely investigated in soil stabilization. In this paper, calcium chloride was used as ionic crosslinker to enhance recently proposed Persian gum biopolymer as a novel polysaccharide-based additive for clayey soil stabilization. A group of macro and micro scale tests including unconfined compressive strength (UCS), direct shear test (DS), freeze thaw durability, scanning electron microscopy (SEM), stereo zoom microscopy (SZM), Brunauer, Emmett and Teller (N2-BET) and X-ray diffraction (XRD) were conducted. The tests were also performed on soil treated with xanthan gum as a common hydrocolloid of soil stabilization. As the results show, the introduced ionic crosslinked hydrogel at its optimum content has superior performance than well-known xanthan gum in terms of soil strength and ductility. Crosslinking has also positive effects on durability results of pure Persian gum to make it comparable to xanthan gum. Consumption of lower amounts of Persian gum at presence of ionic crosslinker can make stabilization projects more economical efficient. Microscale tests also confirmed the powerful impact of optimum modified hydrogel on soil interstructure by filling the pores, agglomeration of soil particles and formation of new cementitious compounds in the mineralogical structure of the soil.

Lignin, the second most plentiful biopolymer, is produced on a large scale as the waste of the pulp and paper industries. Conventionally, lignin is incinerated for energy generation, while less tha...

The improved properties of Euchema cottoni biopolymer films are significant determinants as a functional material. In this study, cinnamon oil extract reinforced cellulose nanofibre biopolymer films were fabricated. The CNF isolated via supercritical CO2 was obtained from bamboo precursor to enhance the properties of the films at different concentrations of cinnamon essential oil obtained from cinnamon bark which were incorporated in the matrix networks. The physico-chemical, thermal and antimicrobial properties of the isolated CNF reinforced E. cottoni biopolymer films was obtained using scanning electron microscopy (SEM), Fourier transmission irradiation (FT-IR), Atomic forced microscopy (AFM), water contact angle measurement (WCA), thermogravimetric analysis (TGA) and antimicrobial properties. The characterization study was carried out for improved mechanical, thermal, morphological, wettability and antimicrobial properties. The result revealed that the morphology, mechanical, and wettability properties of the biopolymer films were significantly enhanced with the incorporation of 1, 2, 3 and 4% (w/w) of cinnamon essential oil in the matrix structure containing CNF. The hydrophobic property of the film was enhanced with the incorporation of cinnamon oil extract indicated decrease in surface roughness of the films which were exhibited by increased water contact angle compared to the neat film. The homogenous dispersion of CNF resulted to decreased surface roughness relative to the neat film by 314.96 to 48.30 Rq respectively. The hydrophobicity of the films increased as concentration of cinnamon oil in the matrix component was increased as the surface roughness decreased. Increased hydrophobic property of the film was noticed after the incorporation of 3% concentration of cinnamon oil with equivalent contact angle of 92.36○. The tensile properties of the biopolymer film was significantly improved as SW/CNF/C3 cinnamon oil was incorporated in the matrix. The optimum tensile strength was exhibited by the film by the addition of 3% concentration of essential oil, 75.2% cinnamaldehyde was contained in the oil extract. The E. cottoni derived biopolymer film demonstrated satisfactory mechanical and thermal stability including improved surface hydrophobicity. Furthermore, the biofilms exhibited good inhibition activity against Staphylococcus aureus and Escherichia coli bacteria with the incorporation of the cinnamon oil extract with inhibition zone diameter at 26.94 ± 9.4 and 30.28 ± 0.46 respectively indicating effective antimicrobial activities of the biofilm. The functional properties of the fabricated biopolymer film was enhanced with the addition of cinnamon oil.

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.

Recently, the demand for biodegradable, eco-friendly and sustainable alternatives has been on the increase. Although numerous biopolymers such as cellulose, starch, plants proteins and polylactic acid, etc., have been used to produce bioplastics, the outcomes need more improvement to suit different applications. This paper comprehensively maps the expanding academic territory using lignin as a reinforcement material to improve biopolymers-based materials' properties. A brief discussion on the chronological development of lignin, types, isolation, physical and chemical modifications was presented. Also, the role of lignin in biopolymeric blends such as starch, polylactic acids, plants proteins, polyhydroxy butyrate and polyamides was reviewed. Finally, the review extensively and critically discusses the current findings on lignin/biopolymers blends in various industrial applications, including wood adhesives, adsorbent for toxic heavy metal removal, production of carbon materials, dispersant medium, flame retardant and storage materials, etc., and highlighted the possible applications of lignin in biofuel, hydrocarbon, lubricant, renewable chemical, and smart materials.

In this study, a novel biopolymer based on poly(glycerol sebacic)-urethane (PGS-U) and its nanocomposites containing Cloisite@30B were synthesized by facile approach in which the crosslinking was created by aliphatic hexamethylene diisocyanate (HDI) at room temperature and 80 °C. Moreover, metronidazole and tetracycline drugs were selected as target drugs and loaded into PGSU based nanocomposites. A uniform and continuous microstructure with smooth surface is observed in the case of pristine PGS-U sample. The continuity of microstructure is observed in the case of all bionanocomposites. XRD result confirmed an intercalated morphology for PGSU containing 5 wt% of clay nanoparticles with a d-spacing 3.4 nm. The increment of nanoclay content up to 5%, the ultimate tensile stress and elastic modulus were obtained nearly 0.32 and 0.83 MPa, which the latter was more than eight-fold than that of pristine PGS-U. A sustained release for both dugs was observed by 200 h. The slowest and controlled drug release rate was determined in the case of PGSU containing 5 wt% clay and cured at 80 °C. A non-Fickian diffusion can be concluded in the case of tetracycline release via PGS-U/nanoclay bionanocomposites, while a Fickian process was detected in the case of metronidazole release by PGS-U/nanoclay bionanocomposites. As a result, the designed scaffold showed high flexibility, which makes it an appropriate option for utilization in the treatment of periodontal disease.

Hydroxypropylmethylcellulose (HPMC) is popularly known as a hydrocolloid for potential use as a biopolymer film. The films of HPMC exhibit brittleness, lacking flexibility, but they can provide a gas barrier. With the aim of improving the HPMC film properties, nanofibrillated cellulose (NFC) from the succulent plant Agave americana L was incorporated as reinforcement material using the solution casting method. The films were prepared with three different amounts of NFC with glycerol as a plasticizer. The incorporation of the NFC into the nanocomposite films showed a 1,000-fold reduction in the gas permeability. However, significant improvements in the tensile strength (TS), the elongation at break (EAB), and Young’s modulus (YM) were only observed with 1% NFC. A higher moisture content (24.5%) and a higher solubility (59.5%) were observed in the HPMC/NFC-1 film, which also exhibited the best biodegradability loss of the films that were observed with a 92.8% degradation rate in 15 d of soil burial studies. Therefore, the results evidence that the HPMC/NFC films might be potentially suitable as food wrap packaging on perishable produce of fruits and vegetables to maintain their quality attributes and prolong the storage life.

In this project, pseudo-poly(amino acid)s (PAAs) containing different amino acids in main chain were synthesized by direct polyesterification of N,N-(pyromellitoyl)-bis-D-4-hydroxyphenylglycine dimethyl ester as biologically active diol with diacid monomer derived from different amino acids was carried by tosyl chloride/pyridine/N,N′-dimethylformamide as a condensing agent. All biological properties of the polymers were determined by biological evaluation in bacterial media. PAAs containing silver nanoparticles were fabricated by in situ method using dimethylformaide (DMF) as a solvent which leads to a spontaneous reduce in room temperature. Furthermore, these biopolymer nanocomposite/Ag thin films were immobilized on glass microbeads. The chemical structures of synthesized PAAs and PAA/Ag nanocomposite (NC) were considered by FTIR, 1H-NMR spectroscopy, transmission electron microscopy (TEM), elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy, and energy dispersive X-ray (EDAX). The results of EDAX and TEM analysis of PAAs/Ag NC showed that silver particles have homogeneous dispersion and uniformity in nano-dimensions about 50 nm in PAAs matrix. The micro glass beads were coated with PAA/Ag nanocomposite thin film and placed in a column through for the disinfecting effect of Escherichia coli in water was evaluated very well.

Bentonite clay is most commonly used as a landfill liner but is resource-intensive and suffers drawbacks like large volume change and desiccation cracking. It also poses construction difficulties and the handling of a large volume of material. In situ soil can be successfully modified into base liners for landfills which offers an economical and sustainable alternative to bentonite liners. In this study, an exocellular biopolymer, xanthan gum, is used to improve the in situ soil and provides a novel alternative liner material. A comparative study is also made by modifying the in situ soil with various percentage of bentonite. The results show that the maximum dry density of the in situ soil increased marginally for both the additives. Hydraulic conductivity decreased from 2.87 × 10–3 to 4.46 × 10–8 cm/s at 1% xanthan gum addition while in case of bentonite it reduces to 4.81 × 10–8 cm/s at 30% addition. This significant reduction in hydraulic conductivity on stabilizing soil with xanthan gum is attributed to gel coating on the soil surface and gel plug formation in the soil matrix, confirmed by morphological studies. Choice of xanthan gum for stabilizing soil and modifying it into baseliners is economical than bentonite clay. The mechanism of bio-plugging in xanthan gum stabilized soil will also control leachate movement through the soil. Hence, xanthan gum, a renewable, sustainable and carbon negative biopolymer, can be successfully used to modify in situ soil into clay liner.

There is an increasing need for materials with tunable physical and chemical properties that are relatively non-toxic and efficacious for their intended application. Many wood stains and finishes emit toxic chemicals which may have serious implications to one’s health. A novel alternative material is realized between xanthan gum and Neodol, a non-ionic surfactant. The resulting three-dimensional film is evaluated as a free-radical scavenger for the protection of wood at different ratios. Atomic force microscopy visualizes the topography and quantifies the local nanomechanics, while rheological measurements showcase a shift from viscoelastic material to gel. Electron plasmon resonance confirms the free-radical reducing ability (3.5 times), while liquid chromatography mass spectroscopy quantifies the UV degradation of sinapyl alcohol. This material has potential, not only in coating industries as a safer option, but also in those industries requiring flexibility and tenability, namely for biosensors and anti-inflammatory therapeutics. Graphic abstract

Polysaccharide biopolymer Agar-Agar extracted from red algae is a natural and biodegradable polymer. It is a combination of agarose (a neutral and linear polymer, with repeated units of agarobiose) and a heterogeneous mixture of agaropectin (a charged sulfated polymer). In this study, a comparative study of structural vibrational and electrochemical properties of agar-agar biopolymer with two different methods HF (Hartree-Fock) and DFT (Density Functional Theory) using a basis set 631+G (d, p) is performed. The comparative structural study of agar-agar biopolymer by HF and DFT method has been carried out to calculate the stability of the molecule. The thermionic properties and Mulliken charge distribution are analysed to deliver a quantitative study of partial atomic charge distribution. The overall vibrational analysis of primal modes of the biopolymer has been studied using FTIR analysis. Based on highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) composition and energies, various chemical parameters of the biopolymer have been evaluated. The Physico-chemical properties of this polysaccharide show a strong correlation with its optimized structure. Agar-agar has its application in the electrochemical, biotechnological, and pharmaceutical fields, as a stabilizer and gelling material.

The goal of this article is to investigate the printability of ethyl cellulose, a biomass derived polymer, using a custom-modified direct ink writing (DIW) printer. Ethyl cellulose is widely used as a thin-film coating in controlled-release vitamins and medical pills as well as a thickener in the food, cosmetics, and other industries, making it an attractive candidate biopolymer for 3D printing. In this work, ethyl cellulose was dissolved in an alpha-terpineol solvent at different solid contents to prepare inks with different viscosities. A custom DIW printer, retrofitted with an in situ infrared curing system, was designed, calibrated, and analyzed for printing ethyl cellulose. The results demonstrate that the printer can maintain a steady flow for a range of ethyl cellulose inks having different viscosities. In summary, DIW can be successfully deployed toward fabricating biopolymer parts.

In this study, plant biopolymer gum Acacia is synthesised and chemically modified by fruit extract of black grapes (Vitis vinifera), eggplant (Solanum melongena). Fruits contain functional groups c...

Background Kefiran is an exopolysaccharide derived from microflora of kefir grains presented in a fermented milk beverage. It has gained researchers' attention due to its biological properties, biocompatibility, film-forming and electrospinning abilities, highlighting its tremendous potential in applications from food packaging to nanomedicine. Scope and approach Herein, we provided a comprehensive review with state-of-the-art composites, nanocomposites and nanofibers based on kefiran useful in food and medical applications. Once kefiran films are naturally brittle, this overview focuses on a structure-properties relationship to understand how other nanostructures and elements can overcome challenges and improve properties required for biodegradable food packaging materials (e.g., water resistance, barrier, and mechanical properties). Key findings and conclusions: Recent progress showed kefiran combined with other polymers as whey protein isolate and waterborne polyurethane, essential oils (EO) and nanofillers as nanocellulose, zinc oxide and alumina nanoparticles with barrier and mechanical properties equivalent or better to synthetic polymers used as standard packaging materials. Moreover, depending on the content added, EO can provide plasticizing effect or reinforcement of interphase in kefiran nanocomposite, adding new functionalities (e.g., UV-protection, antioxidant and antimicrobial features), highlighting its potential in active food packaging. Besides that, migration testing can fill critical gaps and provide progress in the field. Recent advances in kefiran also showed its electrospinning ability to be transformed in nanofiber, potentially useful to encapsulate bioactive ingredients to food, probiotic/drug delivery and scaffolds to tissue engineering. Besides, challenges, current trends and perspectives of these kefiran nanomaterials considering their safety and regulation concerns are also identified and discussed.

Bombyx mori silk fibroin (B. mori SF) is a prospective and promising biomaterial being investigated by the scientific research fraternity around the world for its biomedical applications such as tissue engineered grafts. This consideration of silk fibroin as biomaterial is possible given its suitable mechanical and biological properties. Mechanical properties and behavior of a biopolymer or biomaterial are greatly affected by the chemical environment surrounding it. To assess the suitability of B. mori SF for application as tissue scaffold and graft, it is vitally essential to understand the influence of saline environment (such as provided by extracellular fluids in the physiological conditions and during pre and post-treatments of the fiber or scaffold) on its mechanical behavior and molecular mechanics. Current study investigates the tensile mechanical behavior of B. mori SF under varying saline environments (0 to 4.5 M) using molecular dynamics (MD) simulations. Elastic modulus values of 7 to 20 GPa and peak stress values of 350 to 750 MPa are computed for the two models for 0 to 4.5 M saline environments. Examining the obtained results show that peptide salt interactions are primarily contributing to the enhanced mechanical response of B. mori SF nanostructure. In addition, formation of ionic bridges between the salt ions present in saline environment and peptide strands, facilitating the enhanced mechanical response, are also observed. Ultimately, it is envisioned that the molecular deformation mechanisms and mechanistic understanding extracted from current study can be informative towards future investigation of silk-based biomaterials.

Polymer cryogels are very promising for producing functional materials. Their porous structure makes them indispensable for some areas of medicine, catalysis, and biotechnology. In this review we focused on methods for producing cryogels based on biopolymers, interpolyelectrolyte complexes of biopolymers, and composite cryogels based on them. First, the properties of cryogels and brief theoretical information about the production of cryogels based on biopolymers were considered. The second section summarizes the latest advances in the production of cryogels based on complexes of biopolymers and composite cryogels. The features of the synthesis and the factors affecting the final properties of materials were considered. In the final part the fields of application of cryogels of the considered types in biotechnology, catalysis and medicine were studied in detail. In biotechnology cryogels are used to immobilize molecules and cells, as a basis for cell growth, and as chromatographic materials for cell separation. In catalysis cryogels are used as a matrix for the immobilization of metal nanoparticles, as well as for the immobilization of enzymes. Biocompatible cryogels and their composites are widely used in medicine for bone and cartilage tissue regeneration, drug delivery, providing a long-term profile of drug release in the body.

Bacterial cellulose (BC) is an extracellular homopolymer produced by certain species of bacteria. It has demonstrated the potential as an alternative to plant cellulose with more appealing features such as unique nanostructure, high porosity, high crystallization index, high tensile strength, high water holding capacity, and a high degree of polymerization. These attributes facilitate BC utilization in various applications, ranging from the food industry, cosmetics, pharmaceutical, medical field, waste treatment, textile, and paper industry. Considering the advantages and wide range of applications, it is necessary to explore and improve the current industrial production to achieve a higher yield at a lower cost. This review article summarizes the BC properties and characteristics as well as its application in different fields. Furthermore, the potential of agricultural waste molasses for low-cost BC production is also discussed.

In this report, nanocomposites are composed of surface-functionalized multi-walled carbon nanotubes (f-MWCNTs) and polymers (polyethylene glycol, chitosan) or silver nanoparticles (AgNPs) were successfully synthesized and used as nanocarriers for drug delivery. The drug (Ibrutinib, Ibr) encapsulated with different nanocomposites was used for effective prostate cancer treatment. The as-prepared bioconjugates were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, and Raman spectroscopy. The drug loading efficiency of 95.5% was achieved for f-MWCNTs/AgNPs composite. The drug release profile showed that the f-MWCNTs/AgNPs composite released 79% in 84 h at pH 5.5 indicating the sustainable drug release. Further, these Ibr-loaded nanocomposites were conjugated with T30 oligonucleotides (T30 ODN) for targeting over-expressed prostate-specific membrane antigen in the prostate gland. The prostate anti-cancer activity was evaluated using PC-3 and MDA-MB-231 cancer cells and the results indicated that the Ibr- loaded nanocomposites conjugated with T30 ODN exhibited higher cell killing efficiency compared to the free Ibr. Therefore, these conjugated nanocomposites are effective drug delivery systems for prostate cancer disease targeted therapy.

The packaging of meat and meat products requires specific materials with a focus on the moisture content of food matrix and color stability. The present usage of petroleum-derived packaging materials are becoming obsolete for their non-biodegradability, non-environmental sustainability, and harmful effect on the life of land and aquatic animals, besides humans. Various research attempts were made successfully to use biopolymers for manufacturing eco-friendly packaging materials. But the mechanical, barrier and thermal properties remain not on a par with the films made from polyolefins. Nanomaterials in the form of reinforcing agents or fillers can improve the structural morphology of the biopolymer films rendering them a high-quality barrier, mechanical, thermal, antimicrobial, and antioxidant properties. On the other hand, proper selection of nanomaterials considering the health and safety in the development of nanocomposites is a prerequisite in the formation of biodegradable films. This article reviews various types of biopolymers, nanofillers, biopolymer nanocomposites, antimicrobial nanocomposites, characterization of nanocomposites, health, and safety issues associated with the usage of nanocomposites. The review would impart comprehensive and advanced knowledge in the realm of biodegradable nanocomposite films with special reference to meat and meat products.

Abstract Phosphate-shelled brachiopods differ in filter-feeding lifestyle, with Lingula anatina an active infaunal burrower, and Discinisca tenuis a shallow marine epibenthic animal. The shells of these animals are built of organophosphatic constituents, the organic fibres/sheets reinforced with calcium phosphate to provide a sophisticated ultrastructural robustness. This investigation examined the nature of the organic fibres in order to improve understanding of how living organisms produce hierarchically structured biomaterials. Unlike powdered samples commonly used in previous studies, organic fibres were isolated for the first time and the shell fractions were purified, in order to study the content and nature of the biopolymer fibres. Biochemical methods including Calcofluor staining revealed a chitin matrix. Ultrastructural analysis, thermal gravimetric analysis, and spectroscopic analyses show that the core polysaccharide framework is composed of layers of β-chitin sheets and/or fibrils that are coated with a fibrous organic matrix. There is more chitin matrix in the L. anatina shells (26.6 wt.%) compared to the D. tenuis shells (12.9 wt.%). Taken together, the data show that the chitin matrix contributes to increased skeletal strength, making L. anatina highly adapted for life as an active burrower. In comparison, D. tenuis contains less chitin and lives as attached epibenthos in a shallow marine environment. Graphical abstract First spectroscopic evidence of β-chitin sheets in recent organophosphatic brachiopods