Effect of Polydopamine and Curcumin on Physicochemical and Mechanical Properties of Polymeric Blends

In this study, we prepared composites made from polyvinyl alcohol (PVA), sodium alginate (SA), curcumin (Cur), and polydopamine (PD). The film-forming properties of the composites were researched for potential wound-healing applications. The structures of the polymer blends and composites were studied by FTIR spectroscopy and microscopic observations (AFM and SEM). The mechanical properties were measured using a Zwick Roell testing machine. It was observed that the formation of a polymeric film based on the blend of polyvinyl alcohol and sodium alginate led to the generation of pores. The presence of curcumin in the composite resulted in the alteration of the blend properties. After solvent evaporation, the polymeric blend of PVA, SA, and curcumin formed a stable polymeric film, but the film showed poor mechanical properties. The addition of polydopamine led to an improvement in the mechanical strength of the film and an increase in its surface roughness. A polymeric film of sodium alginate presented the highest surface roughness value among all the studied specimens (66.6 nm), whereas polyvinyl alcohol showed the lowest value (1.60 nm). The roughness of the composites made of PVA/SA/Cur and PVA/SA/Cur/PD showed a value of about 25 nm. Sodium alginate showed the highest values of Young's modulus (4.10 GPa), stress (32.73 N), and tensile strength (98.48 MPa). The addition of PD to PVA/SA/Cur led to an improvement in the mechanical properties. Improved mechanical properties and appropriate surface roughness may suggest that prepared blends can be used for the preparation of wound-healing materials.

Chitosan/snail slime films as multifunctional platforms for potential biomedical and cosmetic applications: physical and chemical characterization

Due to the pollution problem, the use of more sustainable materials with a reduced environmental impact, spanning across biocompatible and biodegradable polymers, is growing worldwide in many different fields, particularly when referring to applications in Life Sciences. Accordingly, with the aim of developing multifunctional materials for potential cosmetic/biomedical purposes, this work reports the physical and chemical characterization of chitosan-based films blended with snail slime, exhibiting antioxidant and sunscreen features. A suitable formulation for preparing free-standing chitosan platforms, mixing low molecular weight chitosan, lactic acid, glycerol, and snail slime into an appropriate ratio, is thus described. The results obtained by morphological analysis and ATR-FTIR spectroscopy, XRD, swelling analysis (also when varying pH, ionic strength, and temperature), and WVTR measurements evidence a uniform distribution of snail slime inside the chitosan network, forming more compacted structures. At first, the UV-Vis analysis is used to investigate the theoretical Sun Protection Factor, finding that these innovative platforms can be used for preventing sunburn. Then, the antioxidant features are investigated using the ABTS assay, displaying a snail slime-mediated and dose-dependent boosted activity.

Collagen and Keratin Hydrolysates to Delay the Setting of Gypsum Plaster

Leather and wool waste represent a high concern due to the low level of valorization and circular economy demands for upcycling of biomass resources. Both biomasses can be easily processed as protein hydrolysates and used as functional additives due to the amphiphilic and tunable properties of collagen and keratin proteins. The chemical, physical, and structural investigations of collagen and keratin hydrolysate properties showed that the chelating abilities due to carboxylic groups can be exploited for gypsum retardant additives. The molecular weights and amino acid compositions of three different hydrolysates showed only slight influences on the setting time of gypsum; all three proteins delayed the setting time of gypsum between 60 and 120 min, as compared to the commercial plaster with a 30 min setting time. Higher molecular weight and more carboxylic active groups showed slight improvements in the setting time of mortars. The improved properties of keratin hydrolysate as compared to low molecular collagen hydrolysate were attributed to foaming and conductive properties. The mechanism of mortar setting delaying through calcium ions complexation by protein hydrolysates was shown by electric conductivity evolution of plasters with and without protein additives over time, supported by foaming properties, amino acid, and functional groups' composition. Lower bending strength values for the higher concentration of proteins do not reduce the potential to use the protein hydrolysates as retardant additives in mortar fabrication.

New Materials Based on Molecular Interaction between Hyaluronic Acid and Bovine Albumin

In this work, the interactions between hyaluronic acid and bovine serum albumin were investigated. The film-forming properties of the mixture were proven, and the mechanical and surface properties of the films were measured. The results showed the interactions between hyaluronic acid and albumin, mainly by hydrogen bonds. Molecular docking was used for the visualization of the interactions. The films obtained from the mixture of hyaluronic acid possessed different properties to films obtained from the single component. The addition of bovine serum albumin to hyaluronic acid led to a decrease in the mechanical properties, and to an increase in the surface roughness of the film. The new materials that have been obtained by blending can form a new group of materials for biomedicine and cosmetology.

Chitosan/Silk Fibroin Materials for Biomedical Applications-A Review

This review provides a report on recent advances in the field of chitosan (CTS) and silk fibroin (SF) biopolymer blends as new biomaterials. Chitosan and silk fibroin are widely used to obtain biomaterials. However, the materials based on the blends of these two biopolymers have not been summarized in a review paper yet. As these materials can attract both academic and industrial attention, we propose this review paper to showcase the latest achievements in this area. In this review, the latest literature regarding the preparation and properties of chitosan and silk fibroin and their blends has been reviewed.

Bioconversion of Keratin Wastes Using Keratinolytic Microorganisms to Generate Value-Added Products

The management of keratinous wastes generated from different industries is becoming a major concern across the world. In each year, more than a billion tons of keratin waste is released into the environment. Despite some trials that have been performed and utilize this waste into valuable products, still a huge amount of keratin waste from different sources is a less explored biomaterial for making valuable products. This indicates that the huge amount of keratin waste is neither disposed properly nor converted into usable products rather thrown away to the environment that causes environmental pollution. Due to the introduction of this waste associated with different pathogenic organisms into soil and water bodies, human beings and other small and large animals are affected by different diseases. Therefore, there is a need for modern and ecofriendly approaches to dispose and convert this waste into usable products. Hence, the objective of this review is to give a concise overview regarding the degradation of keratin waste by biological approaches using keratinase producing microorganisms. The review also focuses on the practical use of keratinases and the economical importance of bioconverted products of keratinous wastes for different applications. Various researches have been studied about the source, disposal mechanisms, techniques of hydrolysis, potential use, and physical and chemical properties of keratin wastes. However, there is negligible information with regard to the use of keratin wastes as media supplements for the growth of keratinolytic microorganisms and silver retrieval from photographic and used X-ray films. Hence, this review differs from other similar reviews in the literature in that it discusses these neglected concerns.

Hyaluronic Acid as a Component of Natural Polymer Blends for Biomedical Applications: A Review

In this review, we provide a report on recent studies in the field of research on the blends of hyaluronic acid with other natural polymers, namely collagen and chitosan. Hyaluronic acid has attracted significant interest in biomedical and cosmetic applications due to its interesting properties. In recent years, blends of hyaluronic acid with other polymers have been studied for new materials development. New materials may show improved properties that are important in the biomedical applications and in cosmetic preparations. In this review paper, the structure, preparation, and properties of hyaluronic acid blends with collagen and chitosan have been discussed and examples of new materials based on such blends have been presented. A comparison of the currently available information in the field has been shown. Future aspects in the field of hyaluronic acid blends and their applications in the biomedical and cosmetic industry have also been mentioned.