Chitosan functionalized poly(vinyl alcohol) for prospects biomedical and industrial applications: A review

High-compatibility properties of Aronia melanocarpa extracts cross-linked chitosan/polyvinyl alcohol composite film for intelligent food packaging

Although the active and intelligent properties of rich in anthocyanin extracts added to films have been extensively studied, there remains a sparsity of research pertaining to the miscibility of blended films. This work focused on the miscibility of the chitosan/polyvinyl alcohol (CP) film caused by the addition of Aronia melanocarpa extracts (AME), which are rich anthocyanins and phenolic acids, and its effect on physicochemical and functional properties. AME facilitated the amidation reaction and ionic interaction of chitosan in CP films, leading to loss of the crystallinity degree of chitosan. Furthermore, the crystal disruption promoted the formation of hydrogen bonds with polyvinyl alcohol (PVA) with the promoted miscibility. CP film incorporated with 8 % AME possessed the highest tensile strength (26.79 MPa), and elongation at break (66.38 %) as well as excellent ultraviolet-visible (UV-vis) light barrier property, water vapor barrier properties, due to its high miscibility degree. Moreover, this film also showed excellent antioxidant, antibacterial activity, and pH response function, which could be used to monitor the storage of highly perishable shrimp. Hence, the AME provided extra functionality and improved miscibility between chitosan and PVA, which showed great potential for the preparation of high-performance bioactive-fortified and intelligent food packaging films.

An Anthocyanin-Based Eco-Friendly Triboelectric Nanogenerator for pH Monitoring and Energy Harvesting

In recent years, renewable and sustainable triboelectric nanogenerators have attracted attention due to their high energy conversion rate, and enhancing their functionality further contributes to their applicability across various fields. A pH-sensitive triboelectric nanogenerator (pH-TENG) has been prepared by electrostatic spinning technology, with anthocyanin as the pH indicator and environmentally friendly polyvinyl alcohol (PVA) as the substrate. Among many friction-negative materials, the pH-TENG exhibits the best combination with fluorinated ethylene propylene (FEP) and yields an open-circuit voltage of 62 V, a short-circuit current of 370 nA, and a transferred charge of 21.8 nC. At a frequency of 3 Hz, it can charge a 4.7 μF capacitor to 2 V within 45 s, effectively powering a thermometer. Furthermore, the presence of anthocyanin does not affect the pH-TENG's power generation performance and enables the monitoring of a wide range of environmental pH changes, with an ΔE change of 28.8 ± 7.6. Therefore, pH-TENG prepared with environmentally friendly materials can bring new available materials to the biological and medical fields.

Chitosan nanocomposite for tissue engineering and regenerative medicine: A review

Regenerative medicine and tissue engineering have emerged as a multidisciplinary promising field in the quest to address the limitations of traditional medical approaches. One of the key aspects of these fields is the development of such types of biomaterials that can mimic the extracellular matrix and provide a conducive environment for tissue regeneration. In this regard, chitosan has played a vital role which is a naturally derived linear bi-poly-aminosaccharide, and has gained significant attention due to its biocompatibility and unique properties. Chitosan possesses many unique physicochemical properties, making it a significant polysaccharide for different applications such as agriculture, nutraceutical, biomedical, food, nutraceutical, packaging, etc. as well as significant material for developing next-generation hydrogel and bio-scaffolds for regenerative medicinal applications. Moreover, chitosan can be easily modified to incorporate desirable properties, such as improved mechanical strength, enhanced biodegradability, and controlled release of bioactive molecules. Blending chitosan with other polymers or incorporating nanoparticles into its matrix further expands its potential in tissue engineering applications. This review summarizes the most recent studies of the last 10 years based on chitosan, blends, and nanocomposites and their application in bone tissue engineering, hard tissue engineering, dental implants, dental tissue engineering, dental fillers, and cartilage tissue engineering.

Characterisation and functionalisation of chitosan nanoparticles as carriers for double-stranded RNA (dsRNA) molecules towards sustainable crop protection

The need to minimise the impact of phytosanitary treatments for disease control boosted researchers to implement techniques with less environmental impact. The development of technologies using molecular mechanisms based on the modulation of metabolism by short dsRNA sequences appears promising. The intrinsic fragility of polynucleotides and the high cost of these techniques can be circumvented by nanocarriers that protect the bioactive molecule enabling high efficiency delivery to the leaf surface and extending its half-life. In this work, a specific protocol was developed aiming to assess the best methodological conditions for the synthesis of low-size chitosan nanoparticles (NPs) to be loaded with nucleotides. In particular, NPs have been functionalised with partially purified Green Fluorescent Protein dsRNAs (GFP dsRNA) and their size, surface charge and nucleotide retention capacity were analysed. Final NPs were also stained with FITC and sprayed on Nicotiana benthamiana leaves to assess, by confocal microscopy, both a distribution protocol and the fate of NPs up to 6 days after application. Finally, to confirm the ability of NPs to increase the efficacy of dsRNA interference, specific tests were performed: by means of GFP dsRNA-functionalised NPs, the nucleotide permanence during time was assessed both in vitro on detached wild-type N. benthamiana leaves and in planta; lastly, the inhibition of Botrytis cinerea on single leaves was also evaluated, using a specific fungal sequence (Bc dsRNA) as the NPs' functionalising agent. The encouraging results obtained are promising in the perspective of long-lasting application of innovative treatments based on gene silencing.

Chitosan-Coated MIL-100(Fe) as an Anticancer Drug Carrier: Theoretical and Experimental Investigation

MIL-100(Fe) was synthesized under biofriendly conditions at room temperature and pressure using iron(II) chloride as the source of iron, and it was coated with chitosan (CS), a natural polysaccharide. In this study, we used a computational technique to predict the amount of drug loading in MIL-100(Fe) and MIL-100(Fe)/CS with molecular dynamics software LAMMPS. Powder X-ray diffraction analysis was conducted to characterize the chitosan-coated MIL-100(Fe) loaded with cyclophosphamide (MIL-100(Fe)/CS/CP). The drug loading and release processes were quantified using UV spectroscopy at 193 nm. The toxic effect of MIL-100(Fe)/CS/CP was determined on human breast cancer (MCF-7) cells. In vivo images and H&E analysis show inhibition properties of MIL-100(Fe)/CS/CP on tumor cells. The conducted research indicates that computational calculation provides a unique insight into the drug adsorption since a proper understanding of the atomic interaction of MIL-100(Fe)/CS with anticancer drugs is important for developing experimental investigations. The biocompatibility and anticancer properties of chitosan molecules enhanced the tumor inhibitory effect of the particles compared with the MIL-100(Fe)/CP and free cyclophosphamide treatments.

Self-healing hydrogels for bone defect repair

Severe bone defects can be caused by various factors, such as tumor resection, severe trauma, and infection. However, bone regeneration capacity is limited up to a critical-size defect, and further intervention is required. Currently, the most common clinical method to repair bone defects is bone grafting, where autografts are the "gold standard." However, the disadvantages of autografts, including inflammation, secondary trauma and chronic disease, limit their application. Bone tissue engineering (BTE) is an attractive strategy for repairing bone defects and has been widely researched. In particular, hydrogels with a three-dimensional network can be used as scaffolds for BTE owing to their hydrophilicity, biocompatibility, and large porosity. Self-healing hydrogels respond rapidly, autonomously, and repeatedly to induced damage and can maintain their original properties (i.e., mechanical properties, fluidity, and biocompatibility) following self-healing. This review focuses on self-healing hydrogels and their applications in bone defect repair. Moreover, we discussed the recent progress in this research field. Despite the significant existing research achievements, there are still challenges that need to be addressed to promote clinical research of self-healing hydrogels in bone defect repair and increase the market penetration.

Application of polyvinyl alcohol/chitosan copolymer hydrogels in biomedicine: A review

Hydrogels is a hydrophilic, cross-linked polymer of three-dimensional network structures. The application of hydrogels prepared from a single polymer in the biomedical field has many drawbacks. The functional blend of polyvinyl alcohol and chitosan allows hydrogels to have better and more desirable properties than those produced from a single polymer, which is a good biomaterial for development and design. In this paper, we have reviewed the progress in the application of polyvinyl alcohol/chitosan composite hydrogels in various medical fields, the different cross-linking agents and cross-linking methods, and the research progress in the optimization of composite hydrogels for their subsequent wide range of biomedical applications.

Zirconium/lanthanum-modified chitosan/polyvinyl alcohol composite adsorbent for rapid removal of fluoride

A novel and easily separable adsorbent in the shape of a membrane for the rapid removal of fluoride from water was prepared after testing Zr, La and LaZr to modify a chitosan/polyvinyl alcohol composite adsorbent (CS/PVA-Zr, CS/PVA-La, CS/PVA-LA-Zr). The CS/PVA-La-Zr composite adsorbent can remove a large amount of fluoride within 1 min of contact time, and the adsorption equilibrium can be reached within 15 min. The fluoride adsorption behavior of the CS/PVA-La-Zr composite can be described by pseudo-second-order kinetics and Langmuir isotherms models. The morphology and structure of the adsorbents were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The adsorption mechanism was studied using Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), and which showed that ion exchange occurred mainly with hydroxide and fluoride ions. This study showed that an easily operable, low-cost and environmentally friendly CS/PVA-La-Zr has the potential to remove fluoride effectively from drinking water in a short time.

Polyvinyl Alcohol-Chitosan Scaffold for Tissue Engineering and Regenerative Medicine Application: A Review

Tissue engineering and regenerative medicine (TERM) holds great promise for addressing the growing need for innovative therapies to treat disease conditions. To achieve this, TERM relies on various strategies and techniques. The most prominent strategy is the development of a scaffold. Polyvinyl alcohol-chitosan (PVA-CS) scaffold emerged as a promising material in this field due to its biocompatibility, versatility, and ability to support cell growth and tissue regeneration. Preclinical studies showed that the PVA-CS scaffold can be fabricated and tailored to fit the specific needs of different tissues and organs. Additionally, PVA-CS can be combined with other materials and technologies to enhance its regenerative capabilities. Furthermore, PVA-CS represents a promising therapeutic solution for developing new and innovative TERM therapies. Therefore, in this review, we summarized the potential role and functions of PVA-CS in TERM applications.

Application of Data Modeling, Instrument Engineering and Nanomaterials in Selected Medid the Scientific Recinal Plant Tissue Culture

At present, most precious compounds are still obtained by plant cultivation such as ginsenosides, glycyrrhizic acid, and paclitaxel, which cannot be easily obtained by artificial synthesis. Plant tissue culture technology is the most commonly used biotechnology tool, which can be used for a variety of studies such as the production of natural compounds, functional gene research, plant micropropagation, plant breeding, and crop improvement. Tissue culture material is a basic and important part of this issue. The formation of different plant tissues and natural products is affected by growth conditions and endogenous substances. The accumulation of secondary metabolites are affected by plant tissue type, culture method, and environmental stress. Multi-domain technologies are developing rapidly, and they have made outstanding contributions to the application of plant tissue culture. The modes of action have their own characteristics, covering the whole process of plant tissue from the induction, culture, and production of natural secondary metabolites. This paper reviews the induction mechanism of different plant tissues and the application of multi-domain technologies such as artificial intelligence, biosensors, bioreactors, multi-omics monitoring, and nanomaterials in plant tissue culture and the production of secondary metabolites. This will help to improve the tissue culture technology of medicinal plants and increase the availability and the yield of natural metabolites.

Visible-UVC upconversion polymer films for prevention of microbial infection

Bacterial infections caused by the growth and reproduction of pathogenic bacteria on wounds are one of the main reasons that hinder wound healing. Antibacterial wound dressings protect wounds from bacterial infections. Herein, we developed a polymeric antibacterial composite film using polyvinyl alcohol (PVA) and sodium alginate (SA) as the substrate. The film used praseodymium-doped yttrium orthosilicate (Y₂SiO₅: Pr³⁺, YSO-Pr) to convert visible light into short-wavelength ultraviolet light (UVC) to kill bacteria. The YSO-Pr/PVA/SA showed upconversion luminescence in photoluminescence spectrometry tests, and the emitted UVC inhibited Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria in antibacterial tests. In vivo animal tests showed that YSO-Pr/PVA/SA is effective and safe for inhibiting bacteria in real wounds. The in vitro cytotoxicity test further confirmed the good biocompatibility of the antibacterial film. In addition, YSO-Pr/PVA/SA exhibited sufficient tensile strength. Overall, this study demonstrates the potential of upconversion materials for use in medical dressings.

Collagen-PVA Films Plasticized with Choline Acetate Ionic Liquid for Sustained Drug Release: UV Shielding, Mechanical, Antioxidant, and Antibacterial Properties

Collagen and poly(vinyl alcohol) films as topical drug delivery systems were developed by plasticization with glycerol and different concentrations of choline acetate ([Cho]Ac) ionic liquid (IL). The results showed that [Cho]Ac improved the performance of the materials and can serve as an alternative to synthetic plasticizers such as glycerol. Ciprofloxacin (CIP) was used as a model drug to study its release behavior. Ready-to-use films were characterized for their optical opacity, solubility, swelling, mechanical properties, water contact angle, surface morphology, surface roughness, antioxidant, and antimicrobial activities. Moreover, X-ray diffraction and Fourier Transform Infrared (FTIR) studies were carried out for molecular characterization of the films. [Cho]Ac used as a plasticizing agent showed excellent antioxidant properties, mechanical strength, and UV shielding properties. Further, [Cho]Ac improves the roughness and decreases the solubility of films. The in vitro release behavior of CIP was investigated at physiological pH (7.4), and the results showed that CIP was released in a more controlled manner due to the incorporation of [Cho]Ac into the films' matrix, while the films constructed with glycerol exhibited burst release of CIP. Moreover, the films loaded with CIP showed excellent antibacterial activity against Gram-negative (Escherichia coli) as well as Gram-positive (Staphylococcus aureus) bacteria. This study provides insight into the use of choline-based ILs as plasticizing agents for the fabrication of protein-polymer composite films for wound dressing and many other applications.

Basella alba stem extract integrated poly (vinyl alcohol)/chitosan composite films: A promising bio-material for wound healing

Natural extract-based bio-composite material for wound healing is gaining much attention due to risk of infection and high cost of commercial wound dressing film causes serious problem on the human well-being. Herein, the study outlines the preparation of Poly (vinyl alcohol)/Chitosan/Basella alba stem extract (BAE) based bio-composite film through solvent casting technique and well characterized for wound healing application. Incorporation of BAE into Poly (vinyl alcohol)/Chitosan matrix has shown existence of secondary interactions confirmed by FT-IR analysis. Good morphology, thermal stability and significant improvement in flexibility (∼63.38 %) of the films were confirmed by SEM, TGA and Mechanical test results, respectively. Hydrophilic property (∼9.04 %), water vapor transmission rate (∼70.07 %), swelling ability (∼14.7 %) and degradation rate (∼14.04 %) were enhanced with increase in BAE content. In-vitro studies have shown good antibacterial activity against foremost infectious bacterial strains S. aureus and E. coli. Additionally, BAE integrated Poly (vinyl alcohol)/Chitosan film has amplified anti-inflammatory (∼79.38 %) property, hemocompatibility and excellent biocompatibility (94.9 %) was displayed by cytotoxicity results. Moreover, in-vitro scratch assay and cell adhesion test results illustrated prominent wound healing (96.5 %) and adhesion. Overall results of the present work proclaim that developed bio-composite film could be utilized as a biomaterial in wound care applications.

Polysaccharides for Biodegradable Packaging Materials: Past, Present, and Future (Brief Review)

The ecological problems emerging due to accumulation of non-biodegradable plastics are becoming more and more urgent. This problem can be solved by the development of biodegradable materials which will replace the non-biodegradable ones. Among numerous approaches in this field, there is one proposing the use of polysaccharide-based materials. These polymers are biodegradable, non-toxic, and obtained from renewable resources. This review opens discussion about the application of polysaccharides for the creation of biodegradable packaging materials. There are numerous investigations developing new formulations using cross-linking of polymers, mixing with inorganic (metals, metal oxides, clays) and organic (dyes, essential oils, extracts) compounds. The main emphasis in the present work is made on development of the polymer blends consisting of cellulose, starch, chitin, chitosan, pectin, alginate, carrageenan with some synthetic polymers, polymers of natural origin, and essential oils.

Nanomaterials-Functionalized Hydrogels for the Treatment of Cutaneous Wounds

Hydrogels have been utilized extensively in the field of cutaneous wound treatment. The introduction of nanomaterials (NMs), which are a big category of materials with diverse functionalities, can endow the hydrogels with additional and multiple functions to meet the demand for a comprehensive performance in wound dressings. Therefore, NMs-functionalized hydrogels (NMFHs) as wound dressings have drawn intensive attention recently. Herein, an overview of reports about NMFHs for the treatment of cutaneous wounds in the past five years is provided. Firstly, fabrication strategies, which are mainly divided into physical embedding and chemical synthesis of the NMFHs, are summarized and illustrated. Then, functions of the NMFHs brought by the NMs are reviewed, including hemostasis, antimicrobial activity, conductivity, regulation of reactive oxygen species (ROS) level, and stimulus responsiveness (pH responsiveness, photo-responsiveness, and magnetic responsiveness). Finally, current challenges and future perspectives in this field are discussed with the hope of inspiring additional ideas.

Hydrophobisation of Silica Nanoparticles Using Lauroyl Ethyl Arginate and Chitosan Mixtures to Induce the Foaming Process

We studied silica suspensions with chitosan and biodegradable synthetic surfactant lauroyl ethyl arginate (LAE). Hydrophilic and negatively charged silica nanoparticles were neutralised due to the coating with chitosan. That presence of LAE led to the partial hydrophobisation of their surface, which favoured their attachment to the surface of a thin foam film. It was found that the presence of small and medium-sized (6–9 nm) hydrophobic particles in the interfacial layer of lamella foam film inhibited the coalescence and coarsening processes, which prolonged the life of the foam. Furthermore, hydrophobising of 30 nm particles allowed the formation of large aggregates precipitating from the mixture under steady-state conditions. These aggregates, however, under the conditions of the dynamic froth flotation process in the foam column, were floated into the foam layer. As a result, they were trapped in the foam film and Plateau borders, effectively preventing liquid leakage out of the foam. These results demonstrate the efficiency of using chitosan-LAE mixtures to remove silica nanoparticles from aqueous phase by foaming and flotation.

Antibacterial and antioxidant properties of Cichorium intybus extract embedded in chitosan nanocomposite nanofibers

Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria acquired serious bacterial resistance against antibiotics. Untreated dangerous infections can cause death. We proposed nanofibers (NFs) of Polyvinyl alcohol (PVA)/Chitosan (CS) nanocomposite embedded with Chicory root extract (CRE) as a safe solution. We determined the best extraction solvent and drying method, 70 % ethanol and freeze-drying, respectively. We investigated the optimal electrospinner parameters for a smooth PVA/CS NFs. Finally, we discovered PVA/CS/CRE-50 mg (F4) to be the most effective antibacterial and antioxidant CRE concentration. Interestingly, it was found that ethanolic extract had the highest yield % at 24.7 % with Total Phenolic Contents (TPC) of 4 mg Gallic Acid Equivalent (GAE)/1 g, 80 % antioxidant activity at 25 mg with an IC50 of 4.15 mg/mL and a Minimum Bactericidal Concentration (MBC) of 100 mg against S. aureus and 25 mg against E. coli. Remarkably, F4 NFs had an IC50 33.32 mg/mL, Entrapment Efficiency 64.89 %, Loading Capacity 4.41 %, obeying Noyes-Whitney release model. F4 had an MBC of 2 mg with both bacterial strains, which proved to be potent antibacterial material that surpasses the pure extract 50 times. F4 has also shown an extraordinary antioxidant activity that exceeds PVA/CS NF activity 23 times.

Bacterial chemotaxis in static gradients quantified in a biopolymer membrane-integrated microfluidic platform

Chemotaxis is a fundamental bacterial response mechanism to changes in chemical gradients of specific molecules known as chemoattractant or chemorepellent. The advancement of biological platforms for bacterial chemotaxis research is of significant interest for a wide range of biological and environmental studies. Many microfluidic devices have been developed for its study, but challenges still remain that can obscure analysis. For example, cell migration can be compromised by flow-induced shear stress, and bacterial motility can be impaired by nonspecific cell adhesion to microchannels. Also, devices can be complicated, expensive, and hard to assemble. We address these issues with a three-channel microfluidic platform integrated with natural biopolymer membranes that are assembled in situ. This provides several unique attributes. First, a static, steady and robust chemoattractant gradient was generated and maintained. Second, because the assembly incorporates assembly pillars, the assembled membrane arrays connecting nearby pillars can be created longer than the viewing window, enabling a wide 2D area for study. Third, the in situ assembled biopolymer membranes minimize pressure and/or chemiosmotic gradients that could induce flow and obscure chemotaxis study. Finally, nonspecific cell adhesion is avoided by priming the polydimethylsiloxane (PDMS) microchannel surfaces with Pluronic F-127. We demonstrated chemotactic migration of Escherichia coli as well as Pseudomonas aeruginosa under well-controlled easy-to-assemble glucose gradients. We characterized motility using the chemotaxis partition coefficient (CPC) and chemotaxis migration coefficient (CMC) and found our results consistent with other reports. Further, random walk trajectories of individual cells in simple bright field images were conveniently tracked and presented in rose plots. Velocities were calculated, again in agreement with previous literature. We believe the biopolymer membrane-integrated platform represents a facile and convenient system for robust quantitative assessment of cellular motility in response to various chemical cues.

Modified PVA membrane for separation of micro-emulsion

Release of liquefied hydrocarbons in domestic and industrial effluents, along with oil spills cause significant adverse effects on the soil, water, aquatic ecosystem, and humans. Thus, selective and cost-effective technology to address this challenge is highly desirable. Here, we report the fabrication of electrospun polyvinyl alcohol (PVA) membrane, modified with glutaraldehyde (GA) and a device thereof, for treatment of oil emulsions and recovery of precious fossil fuel. The modified PVA membranes are super-oleophobic with a high static underwater oil contact angle of 163 ± 3° for motor oil. Investigation of wetting properties suggests that the membrane can efficiently separate different oils such as sesame oil, motor oil, mustard oil, and sunflower oil from their emulsions. The motor oil emulsion with separation efficiency of >99% at an excellent permeate flux of 5128 L/m²·h·bar has been achieved. Thus, the prepared modified PVA membrane construes an easy solution for not only effective treatment of oily wastewater but also for oil recovery with high flux.

Exploring the Impact of Chitosan Composites as Artificial Organs

Chitosan and its allies have in multiple ways expanded into the medical, food, chemical, and biological industries and is still expanding. With its humble beginnings from marine shell wastes, the deacetylated form of chitin has come a long way in clinical practices. The biomedical applications of chitosan are truly a feather on its cap, with rarer aspects being chitosan’s role in tissue regeneration and artificial organs. Tissue regeneration is a highly advanced and sensitive biomedical application, and the very fact that chitosan is premiering here is an authentication of its ability to deliver. In this review, the various biomedical applications of chitosan are touched on briefly. The synthesis methodologies that are specific for tissue engineering and biomedical applications have been listed. What has been achieved using chitosan and chitosan composites in artificial organ research as well as tissue regeneration has been surveyed and presented. The lack of enthusiasm, as demonstrated by the very few reports online with respect to chitosan composites and artificial organs, is highlighted, and the reasons for this lapse speculated. What more needs be done to expand chitosan and its allies for a better utilization and exploitation to best benefit the construction of artificial organs and building of tissue analogs has been discussed.

Effectiveness of bio-dispersant in homogenizing hydroxyapatite for proliferation and differentiation of osteoblast

Hydroxyapatite (HA), an inorganic compound, plays an essential role in the proliferation and differentiation of bone cells. Using cellulose nanocrystals (CNCs) as green dispersants to improve homogenization of HA is promising in the fabrication of nanocomposite scaffolds with biocompatibility for bone tissue engineering. The HA/CNC (HC) nanoparticle suspension was incorporated in polyvinyl alcohol (PVA)-based scaffold to investigate the physical and chemical properties. The PVA/HC composites demonstrated high porous structure and swelling ability for cell attachment and a 3-fold improvement in compressive modulus compared with free HC scaffold. Moreover, the presence of HC nanoparticles has promoted the proliferation and mineralization of pre-osteoblast. Our findings could provide an effective strategy by using bio-dispersants to incorporate mineral elements into synthetic polymers for the fabrication of functional tissue engineering scaffolds.

Preparation of Needleless Electrospinning Polyvinyl Alcohol/Water-Soluble Chitosan Nanofibrous Membranes: Antibacterial Property and Filter Efficiency

Electrospinning is an efficient method of producing nanofibers out of polymers that shows a great potential for the filtration territory. Featuring water-soluble chitosan (WS-CS), a low-pollution process and a self-made needleless machine, PVA/WS-CS nanofibrous membranes were prepared and evaluated for nanofiber diameter, bacteriostatic property, filtration efficiency, pressure drop, and quality factor. Test results indicate that the minimal fiber diameter was 216.58 ± 58.15 nm. Regardless of the WS-CS concentration, all of the PVA/WS-CS nanofibrous membranes attained a high porosity and a high water vapor transmission rate (WVTR), with a pore size of 12.06–22.48 nm. Moreover, the membranes also exhibit bacteriostatic efficacy against Staphylococcus aureus, an optimal quality factor of 0.0825 Pa⁻¹, and a filtration efficiency as high as 97.0%, that is 72.5% higher than that of common masks.

Exploring new marine bacterial species, Alcaligenes faecalis Alca F2018 valued for bioconversion of shrimp chitin to chitosan for concomitant biotechnological applications

The exploitation of chitinous materials seems to be an infinite treasure. To this end, using shellfish waste as the sole carbon/nitrogen source solves environmental challenges while lowering microbial chitinase production costs. Bioconversion of shellfish chitin wastes such as shrimp shells has recently been investigated for the production of enzymes and bioactive materials in order to maximize the utilization of chitin-containing seafood processing wastes. In this study, the bioconversion of chitin to chitosan by Alcaligenes faecalis Alca F2018 revealed the highest chitin deacetylase (CDA) activity of 40.6 U/μg. The resulted low K_m and high V_max values explain the high affinity of the purified CDA to the p-nitroacetanilide substrate. CDA with a molecular weight of 66 KDa was purified from F2018 strain, with a 14.5% yield. FT-IR revealed distinct chitosan peaks and XRD revealed that chitosan samples had lower crystallinity than chitin. TGA analysis revealed that the recovered chitosan samples were more thermally stable. The deacetylation degree percentages of the produced chitosan are in the same range as that of the commercial chitosan, suggesting the promising potential of A. faecalis Alca F2018 to utilize shrimp shells in their raw form in the fermentation media based on its CDA enzyme activity.

Effect of Molecular Weight and Nanoarchitecture of Chitosan and Polycaprolactone Electrospun Membranes on Physicochemical and Hemocompatible Properties for Possible Wound Dressing

Tissue engineering has focused on the development of biomaterials that emulate the native extracellular matrix. Therefore, the purpose of this research was oriented to the development of nanofibrillar bilayer membranes composed of polycaprolactone with low and medium molecular weight chitosan, evaluating their physicochemical and biological properties. Two-bilayer membranes were developed by an electrospinning technique considering the effect of chitosan molecular weight and parameter changes in the technique. Subsequently, the membranes were evaluated by scanning electron microscopy, Fourier transform spectroscopy, stress tests, permeability, contact angle, hemolysis evaluation, and an MTT test. From the results, it was found that changes in the electrospinning parameters and the molecular weight of chitosan influence the formation, fiber orientation, and nanoarchitecture of the membranes. Likewise, it was evidenced that a higher molecular weight of chitosan in the bilayer membranes increases the stiffness and favors polar anchor points. This increased Young's modulus, wettability, and permeability, which, in turn, influenced the reduction in the percentage of cell viability and hemolysis. It is concluded that the development of biomimetic bilayer nanofibrillar membranes modulate the physicochemical properties and improve the hemolytic behavior so they can be used as a hemocompatible biomaterial.

Preparation and characterization of antibacterial bacterial cellulose/chitosan hydrogels impregnated with silver sulfadiazine

Hydrogels with pH sensitivity and stable mechanical and antibacterial properties have many desirable qualities and broad applications. A hydrogel based on bacterial cellulose and chitosan, impregnated with silver sulfadiazine (<1% w/w), was prepared using glutaraldehyde as the crosslinking agent. The presence of SSd was confirmed by Fourier transform infrared spectroscopy. Micropore size, swelling ratio, pH- sensitivity, and gram positive and negative antibacterial properties were studied by disk diffusion and colony forming unit. X-ray diffraction confirmed the presence of amorphous and crystalline regions in the hydrogel matrix following addition of SSd. The elemental composition, morphology, and mechanical properties of the hydrogels were characterized. Incorporation of SSd into bacterial cellulose-chitosan hydrogels significantly improved their mechanical and antibacterial properties. The antibacterial activity against E. coli and S. aureus was evaluated and SSd-BC/Ch hydrogels are more toxic to S. aureus than to E. coli. We use FESEM to observe bacterial morphology before and after exposure to SSd-BC/Ch hydrogels. The BacLight LIVE/DEAD membrane permeability kit is used to evaluate the membrane permeability of bacteria. These antibacterial hydrogels have many promising applications in food packaging, tissue engineering, drug delivery, clinical, biotechnological, and biomedical fields.

Preparation and characterization of a novel hamada scoparia polysaccharide composite films and evaluation of their effect on cutaneous wound healing in rat

This work was intended to prepare biodegradable and edible films from polysaccharide extracted from Hammada scoparia leaves (named PSP) and reinforced by poly (vinyl alcohol) (PVA). Four films with different ratios of PSP/PVA: P1 (70:30), P2 (50:50), FP3 (30:70) and pure PVA (100 % PVA) were prepared and characterized in terms of structural (FT-IR), physical (Thickness, solubility and swelling index), optical and thermal properties (TGA). The antioxidant activities of different films were determined in vitro and evaluated in vivo through the examination of wound healing capability. Data revealed that the film P1 displayed the highest antioxidant activity in vitro and accelerated significantly the wound healing, after sixteen days of treatment, attested by higher wound appearance scores and a higher content of collagen (765.924 ± 4.44 mg/g of tissue) confirmed by histological examination, when compared with control, CYTOL CENTELLA® and pure PVA-treated groups. Overall, these results demonstrated that PSP/PVA based films exhibited a higher wound healing potential confirmed with the high antioxidant activities in vitro.

A State-of-the-Art Review on Biowaste Derived Chitosan Biomaterials for Biosorption of Organic Dyes: Parameter Studies, Kinetics, Isotherms and Thermodynamics

Chitosan is a second-most abundant biopolymer on earth after cellulose. Its unique properties have recently received particular attention from researchers to be used as a potential biosorbent for the removal of organic dyes. However, pure chitosan has some limitations that exhibit lower biosorption capacity, surface area and thermal stability than chitosan composites. The reinforcement materials used for the synthesis of chitosan composites were carbon-based materials, metal oxides and other biopolymers. This paper reviews the effects of several factors such as pH, biosorbent dosage, initial dye concentration, contact time and temperature when utilizing chitosan-based materials as biosorbent for removing of organic dyes from contaminated water. The behaviour of the biosorption process for various chitosan composites was compared and analysed through the kinetic models, isotherm models and thermodynamic parameters. The findings revealed that pseudo-second-order (PSO) and Langmuir isotherm models were best suited for describing most of the biosorption processes or organic dyes. This indicated that monolayer chemisorption of organic dyes occurred on the surface of chitosan composites. Most of the biosorption processes were endothermic, feasible and spontaneous at the low temperature range between 288 K and 320 K. Therefore, chitosan composites were proven to be a promising biosorbent for the removal of organic dyes.

A review on chitosan-based membranes for sustainable CO2 separation applications: Mechanism, issues, and the way forward

Effective carbon dioxide (CO₂) separation by nominal energy utilization is the factual attempt in the present era of energy scarcity and environmental calamity. In this perspective, the membrane- based gas separation technology is a budding endeavour owing to its cost -effectiveness, ease of operational maintenance and compact modular design. Among various membrane materials, bio-based polymers are of interest as they are abundant and can be obtained from renewable resources, and can also reduce our dependency on exhaustible fossil fuel-based sources. In this review, the structure-property relationship of chitosan and some of its film-forming derivatives has been critically studied for the first time in view of the fundamental properties required for gas separation applications. Various factors affecting the gas permeation performance of chitosan-based membranes have been highlighted along with prospects and propositions for the design of a few novel bio-based membranes based on the exhaustive analyses.

Biocompatibility Study of Electrospun Nanocomposite Membranes Based on Chitosan/Polyvinyl Alcohol/Oxidized Carbon Nano-Onions

In recent decades, the number of patients requiring biocompatible and resistant implants that differ from conventional alternatives dramatically increased. Among the most promising are the nanocomposites of biopolymers and nanomaterials, which pretend to combine the biocompatibility of biopolymers with the resistance of nanomaterials. However, few studies have focused on the in vivo study of the biocompatibility of these materials. The electrospinning process is a technique that produces continuous fibers through the action of an electric field imposed on a polymer solution. However, to date, there are no reports of chitosan (CS) and polyvinyl alcohol (PVA) electrospinning with carbon nano-onions (CNO) for in vivo implantations, which could generate a resistant and biocompatible material. In this work, we describe the synthesis by the electrospinning method of four different nanofibrous membranes of chitosan (CS)/(PVA)/oxidized carbon nano-onions (ox-CNO) and the subdermal implantations after 90 days in Wistar rats. The results of the morphology studies demonstrated that the electrospun nanofibers were continuous with narrow diameters (between 102.1 nm ± 12.9 nm and 147.8 nm ± 29.4 nm). The CS amount added was critical for the diameters used and the successful electrospinning procedure, while the ox-CNO amount did not affect the process. The crystallinity index was increased with the ox-CNO introduction (from 0.85% to 12.5%), demonstrating the reinforcing effect of the nanomaterial. Thermal degradation analysis also exhibited reinforcement effects according to the DSC and TGA analysis, with the higher ox-CNO content. The biocompatibility of the nanofibers was comparable with the porcine collagen, as evidenced by the subdermal implantations in biological models. In summary, all the nanofibers were reabsorbed without a severe immune response, indicating the usefulness of the electrospun nanocomposites in biomedical applications.

Adsorption study of lac dyes with chitosan coated on silk fibroin using molecular dynamics simulations

Silk is a protein polymer composed of the polypeptide chains including the repeating units of glycine and alanine. Lac dye is composed mainly of two major anthraquinone based components: laccaic acids A and B. Previously, chitosan was reported and used to coat silk in the lac dyeing process for enhancing the uptake of lac dye on silk. Therefore, this work aims to explain why chitosan can help in lac dyeing process on silk by using molecular docking and molecular dynamics (MD) simulations. The molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) analysis was also applied to calculate the binding free energy. The results revealed the attractive interaction between silk and chitosan. Moreover, an increasing unit of acetylglucosamine in the chitosan structure increases the binding interaction between silk and chitosan. After that, the binding between silk complexed with chitosan and laccaic acids A and B were reported. It was clearly found that the average of binding free energies between lac dyes and silk complexed with chitosan (-257.7 and -230.9 kJ/mol) was lower than those between lac dyes and silk without chitosan (-13.4 and -108.5 kJ/mol) indicating the better binding of lac dyes when chitosan is added on the silk surface. The obtained results can be explained why the existence of chitosan on silk surface could increase the binding of lac dyes. Therefore, this study can be used as a guideline in order to understand and improve the fastness properties of textiles.

Antimicrobial and Wound Healing Properties of FeO Fabricated Chitosan/PVA Nanocomposite Sponge

Diabetic and anemia-associated diabetic wounds increase the considerable morbidity and mortality in people, as reported by clinical studies. However, no anemia-associated diabetic wound dressing materials have been developed until now. Hence, this study aimed to develop a nanocomposite scaffold composed of chitosan (CS), poly (vinyl alcohol) (PVA), and phytogenic iron oxide nanoparticles (FeO NPs), for accelerated anemia-associated diabetic wound healing. The aqueous leaves extract of Pinus densiflora (PD) was utilized for the synthesis of iron oxide nanoparticles (FeO NPs). TEM and elemental analysis confirmed smaller size PD-FeO NPs (<50 nm) synthesis with the combination of iron and oxide. In addition, in vitro biological studies displayed the moderate antioxidant, antidiabetic activities, and considerable antibacterial activity of PD-FeO NPs. Further, the different concentrations of PD-FeO NPs (0.01, 0.03, and 0.05%) incorporated CS/PVA nanocomposites sponges were developed by the freeze-drying method. The porous structured morphology and the presence of PD-FeO NPs were observed under FE-SEM. Among nanocomposite sponges, PD-FeO NPs (0.01%) incorporated CS/PVA sponges were further chosen for the in vitro wound-healing assay, based on the porous and water sorption nature. Furthermore, the in vitro wound-healing assay revealed that PD-FeO NPs (0.01%) incorporated CS/PVA has significantly increased the cell proliferation in HEK293 cells. In conclusion, the CS/PVA-PD-FeO NPs (0.01%) sponge would be recommended for diabetic wound dressing after a detailed in vivo evaluation.

Miscibility Studies of Hyaluronic Acid and Poly(Vinyl Alcohol) Blends in Various Solvents

In this study, blends based on hyaluronic acid (HA) and poly(vinyl alcohol) (PVA) were characterized by the viscometric method, steady shear rheological tests and FTIR spectroscopy (Fourier Transform Infrared Spectroscopy). Viscometric studies showed the miscibility of HA and PVA in distilled water: 0.1 mol dm-3 NaCl and 0.1 mol dm-3 HCl. The method proposed by Garcia et al. was applied to assess the miscibility of polymers, while Δ[η] and Δb were introduced to determine of miscibility from the Huggins plots. The viscometric data showed that the attractive forces of HA and PVA were dominant when dissolved in 0.1 mol dm-3 NaCl and 0.1 mol dm-3 HCl, while, in distilled water, repulsive forces played the leading role. All polymer solutions were well characterized using a power law model, and exhibited non-Newtonian behavior with pseudoplasticity increasing with the increasing weight fraction of HA in 0.1 mol dm-3 NaCl and 0.1 mol dm-3 HCl. FTIR studies exhibited the formation of new intermolecular interactions between HA and PVA via hydrogen bonding.

Interfacial Electrofabrication of Freestanding Biopolymer Membranes with Distal Electrodes

Using electrical signals to guide materials' deposition has a long-standing history in metal coating, microchip fabrication, and the integration of organics with devices. In electrodeposition, however, the conductive materials can be deposited only onto the electrode surfaces. Here, an innovative process is presented to electrofabricate freestanding biopolymer membranes at the interface of electrolytes without any supporting electrodes at the fabrication site. Chitosan, a derivative from the naturally abundant biopolymer chitin, has been broadly explored in electrodeposition for integrating biological entities onto microfabricated devices. It is widely believed that the pH gradients generated at the cathode deprotonate the positively charged chitosan chains into a film on the cathode surface. The interfacial electrofabrication with pH indicators, however, demonstrated that the membrane growth was driven by the instantaneous flow of hydroxyl ions from the ambient alginate solution, rather than the slow propagation of pH gradients from the cathode surface. This interfacial electrofabrication produces freestanding membrane structures and can be expanded to other materials, which presents a new direction in using electrical signals for manufacturing.

Chitosan: A Natural Biopolymer with a Wide and Varied Range of Applications

Although chitin is of the most available biopolymers on Earth its uses and applications are limited due to its low solubility. The deacetylation of chitin leads to chitosan. This biopolymer, composed of randomly distributed β-(1-4)-linked D-units, has better physicochemical properties due to the facts that it is possible to dissolve this biopolymer under acidic conditions, it can adopt several conformations or structures and it can be functionalized with a wide range of functional groups to modulate its superficial composition to a specific application. Chitosan is considered a highly biocompatible biopolymer due to its biodegradability, bioadhesivity and bioactivity in such a way this biopolymer displays a wide range of applications. Thus, chitosan is a promising biopolymer for numerous applications in the biomedical field (skin, bone, tissue engineering, artificial kidneys, nerves, livers, wound healing). This biopolymer is also employed to trap both organic compounds and dyes or for the selective separation of binary mixtures. In addition, chitosan can also be used as catalyst or can be used as starting molecule to obtain high added value products. Considering these premises, this review is focused on the structure and modification of chitosan as well as its uses and applications.

Functional Chitosan-based Materials for Biological Applications

Background:

Bio-based materials, as the plentiful and renewable resources for natural constituents which are essential for biomedical and pharmaceutical applications, have not been exploited adequately yet. Chitosan is a naturally occurring polysaccharide obtained from chitin, which has recently attracted widespread attention owing to its excellent activity. This review shows the methods of extraction and modification of chitosan and provides recent progress of synthesis and use of chitosan-based materials in biological applications.

Methods:

By consulting the research literature of the last decade, the recent progresses of functional chitosan-based materials for biological applications were summarized and divided into the methods of extraction chitosan, the chemical modification of chitosan, chitosan-based materials for biological applications were described and discussed.

Results:

Chemical modification of chitosan broadens its applications, leading to developing numerous forms of chitosan-based materials with excellent properties. The excellent bioactivity of chitosan-based material enables it serves potential applications in biomedical fields.

Conclusion:

Chitosan-based materials not only exhibit the excellent activities of chitosan but also show other appealing performance of combined materials, even give the good synergistic properties of chitosan and its composite materials. Further studies are needed to define the ideal physicochemical properties of chitosan for each type of biomedical applications. The development of various functional chitosan-based materials for biological applications will be an important field of research, and this kind of material has important commercial value.

Chitosan Anchored Nanoparticles in Current Drug Development Utilizing Computer-Aided Pharmacokinetic Modeling: Case Studies for Target Specific Cancer Treatment and Future Prospective

Background:

Recently, in the medical and pharmaceutical fields, biopolymers are extensively used for chemical and mechanical modifications of pharmaceutical dosage forms, which add novel properties, functions, and applications. Structural modification of dosage form by polymers along with redesigning in pharmaceutical and tissue engineering fields, presently being the center of analysis for the modern research world, which utilizes the subtle instruments, precise research strategies and most significantly the excipients.

Method:

Recently, in the medical and pharmaceutical fields, biopolymers are extensively used for chemical and mechanical modifications of pharmaceutical dosage forms, which add novel properties, functions, and applications. Structural modification of dosage form by polymers along with redesigning in pharmaceutical and tissue engineering fields, presently being the center of analysis for the modern research world, which utilizes the subtle instruments, precise research strategies and most significantly the excipients.

Results:

The most remarkable point is that chitosan-drug conjugated nanoparticles (CDNP) can target cancer affected cells with the least attempt to killing the neighbor host cell. It is already proved that the CDNP facilitate the more drugs uptaking or cytotoxicity to a cancerous cell. This overcomes the dosage form designing problems of complexity in the biological mechanism and cell specificity. A computer-aided pharmacokinetic study as well as in-silico design with model fitting can provide the possible finding related to target selectivity and interaction. The computer aided study also reduces time and could make the entire process much cheaper till today, very few research has been reported, such as PyRx with AutoDock, response surface methodology and molecular dynamic simulation in drug delivery for chitosan-drug conjugated nanoparticles.

Conclusion:

Therefore, cancer cell target-specific drug delivery using a natural biopolymer conjugate with a computer-aided pharmacokinetic model will be the thirst area of future research. To get successful anticancer drug formulation, in-silico pharmacokinetic modeling would minimize labor, and expenses, during and prior to the experiment has been extensively discussed in the present review.

Novel mineralized electrospun chitosan/PVA/TiO2 nanofibrous composites for potential biomedical applications: computational and experimental insights

Electrospun nanofibrous materials serve as potential solutions for several biomedical applications as they possess the ability of mimicking the extracellular matrix (ECM) of tissues. Herein, we report on the fabrication of novel nanostructured composite materials for potential use in biomedical applications that require a suitable environment for cellular viability. Anodized TiO2 nanotubes (TiO2 NTs) in powder form, with different concentrations, were incorporated as a filler material into a blend of chitosan (Cs) and polyvinyl alcohol (PVA) to synthesize composite polymeric electrospun nanofibrous materials. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nanoindentation, Brunauer-Emmett-Teller (BET) analysis, and MTT assay for cell viability techniques were used to characterize the architectural, structural, mechanical, physical, and biological properties of the fabricated materials. Additionally, molecular dynamics (MD) modelling was performed to evaluate the mechanical properties of the polymeric PVA/chitosan matrix upon reinforcing the structure with TiO2 anatase nanotubes. The Young's modulus, shear and bulk moduli, Poisson's ratio, Lame's constants, and compressibility of these composites have been computed using the COMPASS molecular mechanics force fields. The MD simulations demonstrated that the inclusion of anatase TiO2 improves the mechanical properties of the composite, which is consistent with our experimental findings. The results revealed that the mineralized material improved the mechanical strength and the physical properties of the composite. Hence, the composite material has potential for use in biomedical applications.