Characteristics Of Biopolymers Research Articles

Biodegradable active films based on Chlorella biomass and cellulose nanocrystals isolated from hemp stalk fibers

Cellulose nanocrystals (CNC)-reinforced biopolymers have emerged as a widely embraced approach for enhancing the characteristics of biopolymers due to their exceptional properties. Biocomposite (Chl-CNC) films were fabricated by blending Chlorella biomass and varying concentrations of CNCs via a solution casting technique. CNCs were effectively isolated from hemp stalk fibers, as confirmed by structural, surface, thermal, and morphological analysis. The crystallinity of films increased by CNC incorporation, which was confirmed by the XRD. The presence of molecular interactions between CNC and protein-rich Chlorella biomass was illustrated with the FTIR analysis. These interactions enhanced the physicochemical properties of the films. Further, films demonstrated a high level of soil biodegradation in the 42 days, while their total phenolic, chlorophyll, carotenoid contents, and antibacterial activity were unaffected by the incorporation of CNCs. The Chl-CNC films, regardless of CNC addition, indicated antimicrobial activity toward Escherichia coli but not Staphylococcus aureus. These results indicate that developed biobased and biodegradable Chl-CNC films could be highly beneficial in active food packaging applications.

Hydrothermal aging and soil biodegradation characteristics of biopolymer based sustainable composites

The current research endeavor examines the water absorption (in-service life) and soil biodegradation (end-of-the-service life) behavior of short sisal fiber (SF) reinforced poly (lactic acid) (PLA) and bio-based poly (butylene succinate) (bio PBS) composites. Samples were fabricated by extrusion-injection molding with varying sisal fiber loading of 10, 20, and 30 wt%. The water absorption test was conducted in distilled water at three distinct temperatures (5, 25, and 45 °C) for 336 h. The sorption behavior of composites was studied experimentally, and detailed diffusion kinetic behavior is discussed using Fickian diffusion models. The impact of fiber content and hydrothermal temperature on water diffusion and maximum water absorption was investigated in detail. A soil burial test was conducted in local farmland soil for 60 days to determine the influence of fiber content on the biodegradation characteristics of composites. After exposure to hydrothermal aging, it was concluded that fiber loading was most significant in affecting the maximum percentage of water absorption, whereas hydrothermal temperature was more relevant for higher water diffusion. Soil burial tests showed that SF/bioPBS composites degraded quickly as compared to PLA composites. Overall, composites made with bio PBS have shown an expected response than PLA composites in terms of water absorption and soil biodegradation.

Growth phase-dependent changes in conformational and physicochemical properties of bacterial surface biopolymers lead to changes in bacterial adhesion strength at nanoscale and macroscale

This study presents a detailed investigation into conformational, physicochemical and adhesive characteristics of biopolymers on the surfaces of Escherichia coli and potential probiotic Bacillus subtilis harvested from middle-exponential phase (mid-EP), late-exponential phase (late-EP) and early-stationary phase (early-SP) of growth. The lengths to which bacterial surface biopolymers extend (biopolymer brush lengths), densities of grafted bacterial surface biopolymers indicating the amounts of molecules covering the bacterial surfaces (biopolymer grafting densities), adhesion forces of bacterial surface biopolymers to the model inert surfaces of silicon nitride (Si3N4), and the pull-off distances of biopolymers from Si3N4 were measured in water by atomic force microscopy (AFM). The Weibull analysis of AFM adhesion data showed that as the culture aged, the adhesive bonds between Si3N4 AFM tips and surface molecules of E. coli harvested from the culture were broken with a higher applied force. However, the highest applied force to break the bonds was required for B. subtilis in late-EP, followed by those required for cells in early-SP and mid-EP, respectively. The results of a steric model fitting to AFM approach force-distance (FD) curves and analysis of the pull-off distances in the AFM retraction FD curves showed higher biopolymer grafting density for E. coli in early-SP and longer biopolymer brush layer for B. subtilis in late-EP, which were associated with stronger adhesion to Si3N4 in water. The results of thermodynamic adhesion energy calculations based on the Wu model showed that polar interaction energy dominated the bacterial adhesion at the macroscale, the strength of which varied as a function of the growth phase for both E. coli and B. subtilis. The growth phase-dependent variation in polar components of thermodynamic adhesion energies between the bacteria and Si3N4 in water was consistent with the growth phase-dependent variation in the bond strengths between the bacteria and Si3N4 in water as revealed by the Weibull analysis of AFM adhesion data. Therefore, information obtained by Weibull analysis of nanoscale AFM bacterial adhesion data can be used to predict macroscale bacterial adhesion to the model inert Si3N4 surface in water.

Ways of Import-Substituting Proteins of Collagen Group and Possibilities of Express-Methods of Research

The article provides new data concerning the structure and features of biopolymers that form the basis of by-product collagen-containing raw materials of meat processing industry and the sector of primary treatment of collagen-containing raw materials. In order to resolve the problem of import-substitution, analysis of the structure and features of complicated proteins the author analyzed briefly the economic situation, showed results of investigating certain properties of protein systems and put forward recommendations on the subject development. Theoretical findings can be used for the development of food additive technologies, lipid fraction substitutions, food toppings, food with non-conventional structure and properties, specialized nutrition, including additives of the sport group. According to the author, product groups in demand will include matters, ingredients, food with high biological activity, bio-compatible or modified gels, combined gels, cosmetic preparations, remedy for stimulating growth and development in plants, animals, nano- and bio-structures, polymers with shape memory meant for robotized constructions, etc. Unfortunately, there is no systemized principle for developing the necessary knowledge base for home or overseas products in this segment, however, the author can recommend theoretical and methodological approaches to protein system production, control over their quality, database and academic site development.

Electrostatic spray drying: A new alternative for drying of complex coacervates

Complex coacervation can be used for controlled delivery of bioactive compounds (i.e., flaxseed oil and quercetin). This study investigated the co-encapsulation of flaxseed oil and quercetin by complex coacervation using soluble pea protein (SPP) and gum arabic (GA) as shell materials, followed by innovative electrostatic spray drying (ES). The dried system was analyzed through encapsulation efficiency (EE) and yield (EY), morphological and physicochemical properties, and stability for 60 days. Small droplet size emulsions were produced by GA (in the first step of complex coacervation) due to its greater emulsifying activity than SPP. Oil EY and EE, moisture, and water activity in dried compositions ranged from 75.7 to 75.6, 76.0–73.4 %, 3.4–4.1 %, and 0.1–0.2, respectively. Spherical microcapsules were created with small and aggregated particle size but stable for 60 days. An amount of 8 % of quercetin remained in the dried coacervates after 60 days, with low hydroperoxide production. In summary, when GA is used as the emulsifier and SPP as the second biopolymer in the coacervation process, suitable coacervates for food applications are obtained, with ES being a novel alternative to obtain coacervates in powder, with improved stability for encapsulated compounds. As a result, this study helps provide a new delivery system option and sheds light on how the characteristics of biopolymers and the drying process affect coacervate formation.

Physical characteristics of biopolymers obtained from cereal starch biomolecules

Natural biopolymers have been of great help, due to the versatility of their mechanical, biodegradable and biocompatible properties. They have been adapted for different uses. In the present work the elaboration on a laboratory scale of biopolymers of cereals Zea mays, Sorghum and Triticum is shown, the obtaining of the starch biomolecules by means of alkaline extraction [1], edible chemical modifiers such as citric, tartaric and ascorbic acid were used, glycerin as plasticizer and distilled water for hydration. Eleven experiments E1, E2, E3, E4, E5, E6, E7, E8, E9, E10, E11 were carried out under two drying conditions: room temperature and a Felisa oven at 30±1°C for 24 hours. Experiments E1, E2, E3, E4, E7 were made with biomolecules extracted from the starch of the three cereals mentioned, using citric acid as a chemical modifier and experiments E5, E6, E8, E9, E10 and E11 were carried out with standardized starch. tartaric acid and ascorbic acid in order to compare the stability in its macromolecular matrix of the biopolymers. Concluding that the chemical modifier that provides better physical characteristics such as miscibility in biopolymers was citric acid compared to the use of tartaric acid and ascorbic acid. In addition, it was observed that the less molecular weight of starch biomolecules are used and stability at a temperature of 30 ± 1°C for 24 hours, a stable, cohesive and flexible biopolymer macromolecular matrix is obtained as shown in experiments E3, E4, E7 and E11.

Rheological behavior of zein biopolymer and stiffness characteristic of biopolymer treated soil

The modification of polymeric biomolecules to achieve improved cementation is important for their potential applications. This study presents the rheological behaviors of eco-friendly zein biopolymer and stiffness characteristics of biopolymer-treated soil under various solvent and curing conditions. The rheological and stiffness characteristics of zein biopolymer are evaluated in terms of shear stress, viscosity, and shear wave velocity. The time sensitivity, flow index, and microstructure of biopolymer gel are analyzed. The biopolymer gel generally exhibits a weakly non-Newtonian shear-thickening behavior, except for the specimen cured for 24 h under chamber condition. At a constant shear rate, the biopolymer gel shows a rheopexy behavior, which is characterized by an increase in viscosity over time. The shear wave velocity of biopolymer-treated soil increases with the curing period, up to 50 and 96 % under atmospheric and chamber conditions, respectively. The peak absorption values for the hydroxyl functional group decrease significantly as the curing period and ethanol content increase. Furthermore, the microparticle sizes of the zein biopolymer gel decrease with increasing ethanol content. Therefore, understanding the stiffness characteristics of biopolymer-treated soil specimens for potential soil stabilization can be improved based on the rheological properties of zein biopolymer.

Development of Digital Models of Physical and Mechanical Characteristics of Biodegradable Polymers Using the Example of Compositions Based on Low Density Polyethylene with Natural Rubber

The article discusses the development of digital models of the physical and mechanical characteristics of biodegradable polymers. Based on previous studies of biopolymers, it was determined that the key physicochemical properties of biopolymers for consumers are elongation, tensile strength and weight loss in soil. Since the main characteristic that determines the biodegradation of a polymer is its weight loss in the soil, the authors proposed an approach to the development of a mathematical model of this process. To develop a mathematical model of weight loss in soil for different compositions of biopolymers, it is proposed to use the approximation of the corresponding functional dependencies. As a result of the calculations, it was revealed that the most accurate results of constructing a mathematical model of weight loss in soil for PE/NR compositions are provided by polynomials of 3-4 degrees (the obtained mathematical models are highly accurate, the determination coefficient is at least 0.95). For the practical application of the developed models of the characteristics of biopolymers, an algorithm was proposed for selecting a biopolymer with the properties required for the consumer. The use of this algorithm will allow potential consumers of biopolymers to select the most suitable composition for the production of final products from it, taking into account the required values of physical and mechanical characteristics, as well as the characteristics of biodegradation.

Sustainable biopolymer soil stabilisation: the effect of microscale chemical characteristics on macroscale mechanical properties

Sustainable biopolymer additives offer a promising soil stabilisation methodology, with a strong potential to be tuned to soil’s specific nature, allowing the tailoring of mechanical properties for a range of geotechnical applications. However, the biopolymer chemical characteristics driving soil mechanical property modifications have yet to be fully established. Within this study we employ a cross-scale approach, utilising the differing galactose:mannose (G:M) ratios of various Galactomannan biopolymers (Guar Gum G:M 1:2, Locust Bean Gum G:M 1:4, Cassia Gum G:M 1:5) to investigate the effect of microscale chemical functionality upon macroscale soil mechanical properties. Molecular weight effects are also investigated, utilising Carboxy Methyl Cellulose (CMC). Soil systems comprising of SiO2 (100%) (SiO2) and a Mine Tailing (MT) exemplar composed of SiO2 (90%) + Fe2O3 (10%) (SiO2 + Fe) are investigated. The critical importance of biopolymer additive chemical functionality for the resultant soil mechanical properties, is demonstrated..For Galactomannan G:M 1:5 stabilised soils the ‘high-affinity, high-strength’, mannose-Fe interactions at the microscale (confirmed by mineral binding characterisation) are attributed to the 297% increase in the SiO2 + Fe systems Unconfined Compressive Strength (UCS), relative to SiO2 only. Conversely for SiO2 Galactomannan-stabilised soils, when increasing the G:M ratio from 1:2 to 1:5, a 85% reduction in UCS is observed, attributed to mannose’s inability to interact with SiO2. UCS variations of up to a factor of 12 were observed across the biopolymer–soil mixes studied, in line with theoretically and experimentally expected values, due to the differences in the G:M ratios. The limited impact of molecular weight upon soil strength properties is also shown in CMC-stabilised soils. When considering a soil’s stiffness and energy absorbance, the importance of biopolymer–biopolymer interaction strength and quantity is discussed, further deciphering biopolymer characteristics driving soil property modifications. This study highlights the importance of biopolymer chemistry for biopolymer stabilisation studies, illustrating the use of simple low-cost, accessible chemistry-based instrumental tools and outlining key design principles for the tailoring of biopolymer–soil composites for specific geotechnical applications.Graphical abstract

Complex coacervation of pea protein and pectin: Effect of degree and pattern of free carboxyl groups on biopolymer interaction

In the field of microencapsulation, recently there has been an increasing interest in using plant-based biopolymers for complex coacervation. Since complex formation is based on electrostatic interactions, pectin and pea protein are generally considered as promising materials. However, electrostatic interactions are influenced by several biopolymer characteristics such as net charge and local charge density. Therefore, the aim of the study was to investigate the impact of degree of methoxylation (DM) and pattern of free carboxyl groups of pectin on complex coacervation with soluble pea protein fractions. Six pectin samples varying in DM 62%, 50%, 34% and local charge density (random or blockwise pattern) as well as soluble pea protein fractions were prepared under defined conditions. Interactions were qualitatively tested by turbidity measurement, by visual observation and microscopy. Isothermal titration calorimetry (ITC) allowed a quantitative evaluation of the interactions. A high protein share enhanced protein-pectin interactions, the optimum depended on pectin DM and was found for a mass ratio of 8:1 to 12:1. With respect to pectin, highest level of interaction was observed for pectin with a DM of 50%. The interaction was more pronounced for pectin with random than with blockwise pattern of free carboxyl groups. ITC measurements revealed a higher number of binding sites and a higher binding affinity with protein for pectin with random pattern of free carboxyl groups.

Electrospun hybrid nanofibers: Fabrication, characterization, and biomedical applications.

Nanotechnology is one of the most promising technologies available today, holding tremendous potential for biomedical and healthcare applications. In this field, there is an increasing interest in the use of polymeric micro/nanofibers for the construction of biomedical structures. Due to its potential applications in various fields like pharmaceutics and biomedicine, the electrospinning process has gained considerable attention for producing nano-sized fibers. Electrospun nanofiber membranes have been used in drug delivery, controlled drug release, regenerative medicine, tissue engineering, biosensing, stent coating, implants, cosmetics, facial masks, and theranostics. Various natural and synthetic polymers have been successfully electrospun into ultrafine fibers. Although biopolymers demonstrate exciting properties such as good biocompatibility, non-toxicity, and biodegradability, they possess poor mechanical properties. Hybrid nanofibers from bio and synthetic nanofibers combine the characteristics of biopolymers with those of synthetic polymers, such as high mechanical strength and stability. In addition, a variety of functional agents, such as nanoparticles and biomolecules, can be incorporated into nanofibers to create multifunctional hybrid nanofibers. Due to the remarkable properties of hybrid nanofibers, the latest research on the unique properties of hybrid nanofibers is highlighted in this study. Moreover, various established hybrid nanofiber fabrication techniques, especially the electrospinning-based methods, as well as emerging strategies for the characterization of hybrid nanofibers, are summarized. Finally, the development and application of electrospun hybrid nanofibers in biomedical applications are discussed.

Performance of soil stabilized with biopolymer materials – xanthan gum and guar gum

Biogeotechnology is a subfield of geotechnical engineering that utilizes microbial approaches to improve the engineering parameters of soil. The use of biological processes in the soil reclamation process shows great potential in terms of sustainability and environmental friendly compared to treatment using chemicals such as cement and lime. These additives are recognized to have less ideal environmental impacts due to, in particular, the high quantities of greenhouses that are typically created during production. In this case, one of the potential environmentally friendly and sustainable material options is to use biopolymers obtained from living organisms for soil stabilization, especially in tropical residual soils. However, the physical characteristics of biopolymers fluctuate significantly depending on their types and compositions. The primary purpose of this research is to examine the effects of small quantities of biopolymers on the physical parameters of residual soil (1%, 2%, 4%, and 5%), namely xanthan gum and guar gum. Atterberg limits, optimum water content, maximum dry density, pH, and specific gravity are among the parameters discussed in this research. The shear strengths of both treated and untreated soil at various curing times were experimentally investigated by performing an unconfined compressive strength test. A small amount of biopolymers increased the pH values, reduced the maximum dry density, improved the optimum moisture content, decreased the specific gravity, and also increased the plasticity index. Furthermore, the unconfined compressive strength results highlight that the strength of the soil tends to improve with the addition of biopolymers, highlighting its promising potential for sustainable engineering.

A comprehensive review on recent advances in preparation, physicochemical characterization, and bioengineering applications of biopolymers.

Biopolymers are mainly the polymers which are created or obtained from living creatures such as plants and bacteria rather than petroleum, which has traditionally been the source of polymers. Biopolymers are chain-like molecules composed of repeated chemical blocks derived from renewable resources that may decay in the environment. The usage of biomaterials is becoming more popular as a means of reducing the use of non-renewable resources and reducing environmental pollution produced by synthetic materials. Biopolymers' biodegradability and non-toxic nature help to maintain our environment clean and safe. This study discusses how to improve the mechanical and physical characteristics of biopolymers, particularly in the realm of bioengineering. The paper begins with a fundamental introduction and progresses to a detailed examination of synthesis and a unique investigation of several recent focused biopolymers with mechanical, physical, and biological characterization. Biopolymers' unique non-toxicity, biodegradability, biocompatibility, and eco-friendly features are boosting their applications, especially in bioengineering fields, including agriculture, pharmaceuticals, biomedical, ecological, industrial, aqua treatment, and food packaging, among others, at the end of this paper. The purpose of this paper is to provide an overview of the relevance of biopolymers in smart and novel bioengineering applications.Graphical abstract The Graphical abstract represents the biological sources and applications of biopolymers. Plants, bacteria, animals, agriculture wastes, and fossils are all biological sources for biopolymers, which are chemically manufactured from biological monomer units, including sugars, amino acids, natural fats and oils, and nucleotides. Biopolymer modification (chemical or physical) is recognized as a crucial technique for modifying physical and chemical characteristics, resulting in novel materials with improved capabilities and allowing them to be explored to their full potential in many fields of application such as tissue engineering, drug delivery, agriculture, biomedical, food industries, and industrial applications.

Effect of Cold Plasma Treatment on the Packaging Properties of Biopolymer-Based Films: A Review

Biopolymers, like polysaccharides and proteins, are sustainable and green materials with excellent film-forming potential. Bio-based films have gained a lot of attention and are believed to be an alternative to plastics in next-generation food packaging. Compared to conventional plastics, biopolymers inherently have certain limitations like hydrophilicity, poor thermo-mechanical, and barrier properties. Therefore, the modification of biopolymers or their films provide an opportunity to develop packaging materials with desired characteristics. Among different modification approaches, the application of cold plasma has been a very efficient technology to enhance the functionality and interfacial characteristics of biopolymers. Cold plasma is biocompatible, shows uniformity in treatment, and is suitable for heat-sensitive components. This review provides information on different plasma generating equipment used for the modification of films and critically analyses the impact of cold plasma on packaging properties of films prepared from protein, polysaccharides, and their combinations. Most studies to date have shown that plasma treatment effectively enhances surface characteristics, mechanical, and thermal properties, while its impact on the improvement of barrier properties is limited. Plasma treatment increases surface roughness that enables surface adhesion, ink printability, and reduces the contact angle. Plasma-treated films loaded with antimicrobial compounds demonstrate strong antimicrobial efficacy, mainly due to the increase in their diffusion rate and the non-thermal nature of cold plasma that protects the functionality of bioactive compounds. This review also elaborates on the existing challenges and future needs. Overall, it can be concluded that the application of cold plasma is an effective strategy to modify the inherent limitations of biopolymer-based packaging materials for food packaging applications.

An experimental study on use of biopolymer for sustainable stabilization of slopes

Strength degradation of weathered soil is a major cause of slope failures worldwide. Hence, a proper remediation technique is still a scope of research. Out of two categories of remediation technique, one category relies on external structures supporting the slope which is expensive and the other one relies on stabilizing agents which is economical. In the present study, an attempt has been made to find a solution for sustainable stabilization of soil on slopes using biopolymer. Biopolymers are edible, biocompatible and have no injectability issues. Hence, soil treated with biopolymer does not inhibit plant growth and thus, they are environment friendly, economical and socially inclusive. Two promising biopolymers, namely, Xanthan Gum which is amorphous and Gelatin which is crystalline, have been chosen for experimentation. The soil considered for this has been characterized to be silty sand. Effect of curing period as well as biopolymer concentration on improvement in strength and durability characteristics of biopolymer treated soil have been experimentally investigated. Unconfined Compressive Strength (UCS) has been chosen as a measure of strength characteristics. Weight loss, length change and volume change have been chosen as measures of durability characteristics. Results confirm the feasible application of biopolymers in sustainable slope stabilization. Test results indicate that optimum concentration of Xanthan Gum is a value between 1.5% and 2% and that of Gelatin is 1.25%. Optimum curing period has been observed to lie between 7 and 14 days. A sustainability analysis has also been performed on five combinations of biopolymer treated soil and also on base soil for a comparison.

Advances in biopolymer composites and biomaterials for the removal of emerging contaminants

Abstract Domestic, agriculture, and industrial activities contaminate the waterbodies by releasing toxic substances and pathogens. Removal of pollutants from wastewater is critical to ensuring the quality of accessible water resources. Several wastewater treatments are often used. Researchers are increasingly focusing on adsorption, ion exchange, electrostatic interactions, biodegradation, flocculation, and membrane filtration for the efficient reduction of pollutants. Biopolymers are a combination of two or more products produced by the living organisms used to give the desired finished product with a unique attribute. Biomaterials are also similar to traditional polymers by having higher flexibility, biodegradability, low toxicity, and nontoxic secondary byproducts producing ability. Grafting, functionalization, and crosslinking will be used to enhance the characteristics of biopolymers. The present chapter will illustrate some of the important biopolymers and its compos that will impact wastewater treatment in the future. Most commonly used biopolymers including chitosan (CS), activated carbon (AC), carbon-nanotubes (CNTs), and graphene oxide (GO) are discussed. Finally, the opportunities and difficulties for applying adsorbents to water pollution treatment are discussed.

Fabrication and Comparative Quantitative Analysis of Plasmonic-Polymer Nanocomposites as Optical Platforms.

Plasmonic-polymer nanocomposites can serve as a multifunctional platform for a wide range of applications such as biochemical sensing and photothermal treatments, where they synergistically benefit from the extraordinary optical properties of plasmonic nanoparticles (NPs) and biocompatible characteristics of biopolymers. The field translation of plasmonic-polymer nanocomposites requires design rules for scalable and reproducible fabrication with tunable and predictable optical properties and achieving the best performance. The optical properties of NPs and the optimal analytical performance of nanocomposites could be affected by many fabrication parameters, but a fundamental understanding of such parameters is still minimal. Herein, we systematically investigated the NP distribution and their optical properties in gold nanostar (GNS)-polymer nanocomposites as a function of GNS concentration, polymer identity, and the method of GNS incorporation into a polymer matrix. We performed a comprehensive analysis of the single-particle scattering spectra of GNS incorporated into agarose gel and chitosan hydrogels via embedding and surface deposition, using dark-field spectroscopy. While relative GNS concentration affects the GNS scattering property distribution in both polymer matrices, chemical interactions between a polymer matrix and GNS is the key determinant of the GNS stability and homogenous distribution in nanocomposites. When GNS are embedded in a polymer matrix and there are stronger chemical interactions between GNS and a polymer, significantly less aggregation and a more homogenous distribution of GNS, which leads to a larger percentage of GNS optical property preservation, were observed at all the concentrations. In a proof-of-concept surface-enhanced Raman spectroscopy (SERS) study, we observed that the SERS detection efficiency is dictated by the analyte accessibility of GNS, which is governed by the polymer matrix porosity, polymer-GNS interactions, and other polymer physical characteristics. This work presents the interplay between key fabrication parameters and foundational design parameters for more predictable and reliable fabrication of plasmonic-polymer nanocomposites as an optical platform.

Development and Characterization of Ulvan Polysaccharides-Based Hydrogel Films for Potential Wound Dressing Applications.

BackgroundUlvan is a natural polymer and type of sulfated polysaccharides from green seaweed that could have potential as a candidate for wound dressing material based on the support of its biopolymer characteristics such as antioxidant and antimicrobial activities.ObjectiveIn this study, we developed and prepared three different hydrogel films to explore the potency of ulvan for wound dressing application.MethodsUlvan hydrogel films were prepared by the facile method through ionic crosslinking with boric acid and added glycerol as a plasticizer. The films were evaluated in regard to swelling degree, water vapor transmission (WVTR), Fourier transform infrared (FTIR), powder x-ray diffractometry (P-XRD), scanning electron microscopy (SEM), mechanical properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), antimicrobial, and antioxidant activity.ResultsThe hydrogel films showed that the different concentration of ulvan in the formula affects the characteristics of the hydrogel film. The higher the concentration of ulvan in UHF, the higher the value of viscosity (201±13.45 to 689±62.23 cps for UHF5 to UHF10), swelling degree (82% to 130% for UHF5 to UHF10 at 1 h), moisture content (24%±1.94% to 18.4%±0.51 for UHF5 to UHF10), and the WVTR were obtained in the range 1856–2590g/m2/24h. Meanwhile, the SEM showed porous hydrogel film. Besides, all hydrogel films can reduce hydroxyl radicals and inhibit gram-positive and negative bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Streptococcus epidermidis).ConclusionThe swelling behavior and WVTR of these films are great and could have potential as a wound dressing biomaterial, supported by their antimicrobial and antioxidant properties.

Adsorbent biopolymers based on Couroupita guianensis

Introduction: A biopolymer oil sorbent was produced, aiming to remove oil spills from the sea. More than 80% of the world's energy matrix is still fossil fuels, which meet the energy demands but can potentially harm the environment during its production and processing or through its use (1-6). For this reason, a biopolymer obtained from renewable raw material, the pulp of Couroupita guianensis, a plant native to the Brazilian Amazon region and Atlantic Forest, as well as in other regions of the planet. The motivation of the present work is to synthesize high-density composite packing and absorption composites using the formed biopolymer. The effect of packing density, type, and amount of binder on porous properties as well as thermal conductivity were studied. The biopolymer showed various magnetics nanoparticles contents incorporated into synthesized materials. Methods: In this work, fractions of Couroupita guianensis pulp were prepared and mixed with toluene diisocyanate and tin octanoate. The biopolymer characteristics were prepared with the insertion of maghemite nanoparticles into a polymer matrix, aiming to make the removal of the polymer material containing petroleum from the water surface easier. This study used FTIR spectroscopy (Fourier Transform Infrared Spectroscopy) to assess the biochemical changes. The prepared materials were tested to absorb crude oil. In addition, swelling and mesh parameters including maximum oil absorption (Qmax), swelling kinetics rates, solvent-polymer interaction (χ), effective cross-linking density (ν℮), equilibrium modulus of elasticity (GT) and average molecular weight between cross-links (Mc) were verified and correlated with the absorption efficiency of the synthesized material. Results & Discussions: The FTIR spectrum of the pulp peaks at 3155.54, 2985.81, 1743.65, 1442.75, 1242.16, 1049.28, 933.55, 848.68, 786.96 and 702.09 cm -1 correspond to the functional groups such as carboxylic acids (O–H stretch), alkenes (C–H stretch), carboxylic acids (C=O stretch), aromatics (C–C stretch (in–ring)), alcohols, carboxylic acids, and esters, respectively. The stigmatic tissue; x400 of the sample showing canals equal in number to the carpels; x40.-10. The efficiency of the extract was also confirmed by microscopic visualization. The kinetic curves of ions sorption on modified cellulose phytochemicals of Couroupita guianensis at pH 7 shows that sorption equilibrium in heterogenic system ion–metal–sorbent was attained in 40–60 min. The oil and composite were magnetically removed, and the mass of the oil residue could be determined by gravimetry. In addition, tested materials presented an average cure degree equal to (99.1 ± 0.2)%, which means that, after an oil extraction by solvents, the sorbers can be reused, as proved by three additional tests, which showed that oil removal capability remained the same. Conclusions: Couroupita guianensis fruit extract was presented as a novel bio reductor agent, useful for instant green synthesis of oil-sorbent composite. The addition of magnetic nanoparticles into the polymer matrix allowed the production of a magnetic composite, which possesses a good magnetic force. One single gram of the best material was able to remove 15 g of oil from the water. This result can be improved by changing the amount of magnetic nanoparticles in the material. Key words: Couroupita guianensis, Biopolymer, Sorbent, Magnetic composites, Synthesis References S. Gnanasekar et al., J. Appl. Biomed., 2017, 146, 7 V. Marinho et al, Macromolecular Symp., 2018, 380, 1800116 E. G. Grance et al., J. Appl. Biomed., 2012, xxx H. Bigdoli et al., J. Env. Che. Eng., 2019, 7, 103340 A. Varela et al., Pol. Eng. Sci, 2012, xxx S. Songsaeng et al., J. Adv. Res., 2019, 70, 79-89

Insights into the Role of Biopolymer Aerogel Scaffolds in Tissue Engineering and Regenerative Medicine.

The global transplantation market size was valued at USD 8.4 billion in 2020 and is expected to grow at a compound annual growth rate of 11.5% over the forecast period. The increasing demand for tissue transplantation has inspired researchers to find alternative approaches for making artificial tissues and organs function. The unique physicochemical and biological properties of biopolymers and the attractive structural characteristics of aerogels such as extremely high porosity, ultra low-density, and high surface area make combining these materials of great interest in tissue scaffolding and regenerative medicine applications. Numerous biopolymer aerogel scaffolds have been used to regenerate skin, cartilage, bone, and even heart valves and blood vessels by growing desired cells together with the growth factor in tissue engineering scaffolds. This review focuses on the principle of tissue engineering and regenerative medicine and the role of biopolymer aerogel scaffolds in this field, going through the properties and the desirable characteristics of biopolymers and biopolymer tissue scaffolds in tissue engineering applications. The recent advances of using biopolymer aerogel scaffolds in the regeneration of skin, cartilage, bone, and heart valves are also discussed in the present review. Finally, we highlight the main challenges of biopolymer-based scaffolds and the prospects of using these materials in regenerative medicine.