A bioactive film based on cashew gum polysaccharide for wound dressing applications

Natural gums and their derivatives based hydrogels: in biomedical, environment, agriculture, and food industry

The hydrogels based on natural gums and chemically derivatized natural gums have great interest in pharmaceutical, food, cosmetics, and environmental remediation, due to their: economic viability, sustainability, nontoxicity, biodegradability, and biocompatibility. Since these natural gems are from plants, microorganisms, and seaweeds, they offer a great opportunity to chemically derivatize and modify into novel, innovative biomaterials as scaffolds for tissue engineering and drug delivery. Derivatization improves swelling properties, thereby developing interest in agriculture and separating technologies. This review highlights the work done over the past three and a half decades and the possibility of developing novel materials and technologies in a cost-effective and sustainable manner. This review has compiled various natural gums, their source, chemical composition, and chemically derivatized gums, various methods to synthesize hydrogel, and their applications in biomedical, food and agriculture, textile, cosmetics, water purification, remediation, and separation fields.

Production of anti-inflammatory films based on cashew gum polysaccharide and polyvinyl alcohol for wound dressing applications

In the present study, we aimed to produce CGP/PVA films containing entrapped anti-inflammatory drugs for wound dressing applications. Using a 33-1 fractional factorial design, the effect of each component was evaluated on the physicochemical and morphological properties of the produced materials. The best formulation for entrapment of diclofenac sodium and ketoprofen was also determined. The produced films presented high swelling capacity, with some formulations showing o porous structure. CGP/PVA films showed a maximum retention of 75.6% for diclofenac sodium and 32.2% for ketoprofen, and both drugs were released in a controlled manner for up to 7 h. The drug release kinetic was studied, and the data were fitted using a Korsmeyer-Peppas model, which suggested that the release mechanism is controlled by diffusion. These results indicate that CGP/PVA-based matrices have great potential to be used as drug-delivery systems for wound dressing applications, contributing to prolonging the drug's action time and then improving their anti-inflammatory efficacy.

Evaluation of cashew gum-polyvinyl alcohol (CG-PVA) electrospun nanofiber mat for scarless wound healing in a murine model

Modern-day treatment for burns and wounds demands scarless healing which is becoming a challenging clinical problem. Thus, to alleviate such issues, it becomes essential to develop biocompatible and biodegradable wound dressing material for skin tissue regeneration, which could heal the wound in a very short span leaving no scars. The present study focuses on the development of nanofiber of Cashew gum polysaccharide-Polyvinyl alcohol using electrospinning. The prepared nanofiber was optimized based on uniformity of fiber diameter (FESEM), mechanical property (Tensile Strength), and optical contact angle (OCA) and was subjected to evaluation of: antimicrobial activity against Streptococcus aureus and Escherichia coli, hemocompatibility, and in-vitro biodegradability. The nanofiber was also characterized using different analytical techniques including thermogravimetric analysis, Fourier-transform infrared spectroscopy, and X-ray diffraction. The cytotoxicity was also investigated on L929 fibroblast cells using an SRB assay. The in-vivo wound healing assay showed accelerated healing in comparison to untreated wounds. The in-vivo wound healing assay and histopathological slides of regenerated tissue confirmed that the nanofiber has the potential to accelerate healing properties.

Bio-based and bio-inspired adhesives from animals and plants for biomedical applications

With the "many-headed" slime mold Physarum polycelphalum having been voted the unicellular organism of the year 2021 by the German Society of Protozoology, we are reminded that a large part of nature's huge variety of life forms is easily overlooked - both by the general public and researchers alike. Indeed, whereas several animals such as mussels or spiders have already inspired many scientists to create novel materials with glue-like properties, there is much more to discover in the flora and fauna. Here, we provide an overview of naturally occurring slimy substances with adhesive properties and categorize them in terms of the main chemical motifs that convey their stickiness, i.e., carbohydrate-, protein-, and glycoprotein-based biological glues. Furthermore, we highlight selected recent developments in the area of material design and functionalization that aim at making use of such biological compounds for novel applications in medicine - either by conjugating adhesive motifs found in nature to biological or synthetic macromolecules or by synthetically creating (multi-)functional materials, which combine adhesive properties with additional, problem-specific (and sometimes tunable) features.

Recent Advances in Natural Gum-Based Biomaterials for Tissue Engineering and Regenerative Medicine: A Review

The engineering of tissues under a three-dimensional (3D) microenvironment is a great challenge and needs a suitable supporting biomaterial-based scaffold that may facilitate cell attachment, spreading, proliferation, migration, and differentiation for proper tissue regeneration or organ reconstruction. Polysaccharides as natural polymers promise great potential in the preparation of a three-dimensional artificial extracellular matrix (ECM) (i.e., hydrogel) via various processing methods and conditions. Natural polymers, especially gums, based upon hydrogel systems, provide similarities largely with the native ECM and excellent biological response. Here, we review the origin and physico-chemical characteristics of potentially used natural gums. In addition, various forms of scaffolds (e.g., nanofibrous, 3D printed-constructs) based on gums and their efficacy in 3D cell culture and various tissue regenerations such as bone, osteoarthritis and cartilage, skin/wound, retinal, neural, and other tissues are discussed. Finally, the advantages and limitations of natural gums are precisely described for future perspectives in tissue engineering and regenerative medicine in the concluding remarks.

Use of Statistical Design Strategies to Produce Biodegradable and Eco-Friendly Films from Cashew Gum Polysaccharide and Polyvinyl Alcohol

This work reports the production and characterization of biodegradable and eco-friendly films based on cashew gum polysaccharide (CGP) and polyvinyl alcohol (PVA), using the statistical design strategy. Results show that CGP/PVA films are pH stimuli-responsive, allowing their use in a magnitude of biotechnological applications. The morphological and dimensional characterization evidences a positive influence of polymers in the dimensional properties. In addition, the microstructural analysis shows that films have different morphologies depending on the content of polymers and oxidant agent. On the other hand, the thickness and light transmission values are positively influenced by CGP and PVA and negatively influenced by NaIO₄. Results from mechanical properties show that the traction force is positively influenced by NaIO₄, while the elongation is only affected by the PVA concentration. In summary, considering the morphological, optical and mechanical properties of the CGP/PVA films it is possible to suggest their utilization in different fields as promising packaging materials or matrices for immobilization and/or encapsulation of biomolecules.

Electro-responsive graphene oxide hydrogels for skin bandages: The outcome of gelatin and trypsin immobilization

A free radical polymerization method was adopted for the fabrication of hybrid hydrogel films based on acrylamide and polyethylene glycol dimethacrylate as plasticizing and crosslinking agents, respectively, to be employed as smart skin bandages. Electro-sensitivity, biocompatibility and proteolytic properties were conferred to the final polymer networks by introducing graphene oxide (0.5% w/w), gelatin or trypsin (10% w/w) in the polymerization feed. The physical chemical and mechanical characterization of hybrid materials was performed by means of determination of protein content, Raman spectroscopy, thermogravimetric analysis and measurement of tensile strength. The evaluation of both water affinity and curcumin release profiles (analyzed by suitable mathematical modelling) upon application of an external electric stimulation in the 0-48 voltage range, confirmed the possibility to modulate the release kinetics. Proper proteolytic tests showed that the trypsin enzymatic activity was retained by 80% upon immobilization. Moreover, for all samples, we observed a viability higher than 94% in normal human fibroblast cells (MRC-5), while a reduction of methicillin-resistant Staphylococcus aureus CFU mL^-1 (90%) was obtained with curcumin loaded samples.

Fabrication, characterization, and in vitro evaluation of silver-containing arabinoxylan foams as antimicrobial wound dressing

Arabinoxylan ferulate (AXF) foams were fabricated via enzymatic peroxidase/hydrogen peroxide crosslinking reaction followed by freeze-drying and studied as a potential wound dressing material. The AXF foam's rheological, morphological, porous, and swelling properties were examined. AXF foams were found to be a viscoelastic material that proved to be highly porous and water absorbent. AXF foams possessed low endotoxin levels and were cytocompatible with fibroblasts. Silver was successfully integrated into AXF foams and slowly released over 48 h. AXF foams impregnated with silver demonstrated efficacy inhibiting bacterial growth according to a modified Kirby-Bauer disk diffusion susceptibility test. Overall, AXF foams possess appropriate material properties and the silver-loaded AXF foams showed antimicrobial activity necessary to be a candidate material in wound dressing development. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2456-2465, 2016.

Gums' based delivery systems: Review on cashew gum and its derivatives

The development of delivery systems using natural polymers such as gums offers distinct advantages, such as, biocompatibility, biodegradability, and cost effectiveness. Cashew gum (CG) has rheological and mucoadhesive properties that can find many applications, among which the design of delivery systems for drugs and other actives such as larvicide compounds. In this review CG is characterized from its source through to the process of purification and chemical modification highlighting its physicochemical properties and discussing its potential either for micro and nanoparticulate delivery systems. Chemical modifications of CG increase its reactivity towards the design of delivery systems, which provide a sustained release effect for larvicide compounds. The purification and, the consequent characterization of CG either original or modified are of utmost importance and is still a continuing challenge when selecting the suitable CG derivative for the delivery of larvicide compounds.