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In this work, chitosan/caffeic acid mixtures in the weight ratios of 80/20 and 50/50 were used to obtain thin films enriched with poly(ethylene glycol). It was hypothesized that the presence of caffeic acid indicates the antibacterial properties of the materials (i) and that poly(ethylene glycol) acts as a films modifier (ii). The results showed that by poly(ethylene glycol) addition, the surface free energy as well as mechanical and thermal properties were improved. Moreover, water vapor permeability was observed. All the tested materials showed antioxidant properties in the range of approximately 90%. They also showed antibacterial effectiveness against both Gram-positive and Gram-negative bacteria. The most appropriate material for the application as packaging was composed of chitosan and caffeic acid mixed in a 50/50 weight ratio with 20% PEG addition.

Materials based on carbohydrate polymers may be used for biomedical application. However, materials based on natural polymers have weak physicochemical properties. Thereby, there is a challenge to improve their properties without initiation of toxicity. The alternative method compared to toxic chemical agents’ addition is the use of metal complexation method. In this study, chitosan/tannic acid mixtures modified by Fe(III) complexation are proposed and tested for potential applications as wound dressings. Thereby, surface properties, blood compatibility as well as platelet adhesion was tested. In addition, the periodontal ligament stromal cells compatibility studies were carried out. The results showed that the iron(III) addition to chitosan/tannic acid mixture improves properties due to a decrease in the surface free energy and exhibited a reduction in the hemolysis rate (below 5%). Moreover, cells cultured on the surface of films with Fe(III) showed higher metabolic activity. The current findings allow for the medical application of the proposed materials as wound dressings.

In this work thin film made from the mixture of collagen, hyaluronic acid and chitosan were obtained during solvent evaporation method. The mixtures of biopolymers were modified by dialdehyde starch, which was used as a crosslinking agent. The influence of crosslinking agent on the physico-chemical properties of polymeric matrices was evaluated. The interactions between functional groups of polymers were evaluated by Fourier transform infrared spectroscopy for both unmodified and modified samples. Mechanical properties of film were tested in dry condition using a mechanical testing machine. Morphology of the surface was studied by Atomic Force Microscopy and the roughness parameters were analyzed. Moreover, surface free energy and its polar and dispersive components were evaluated by contact angle measurements. It was found that the addition of dialdehyde starch modified all tested parameters of the studied films. Samples became less elastic and more resist for rupture. Moreover, samples became less rough after crosslinking process and surface free energy increased. Thin film made from the mixture of collagen, hyaluronic acid and chitosan crosslinked with dialdehyde starch can be applied in medicine and in cosmetics.

Hydrogels based on collagen/β-glucan crosslinked with tannic acid were obtained by neutralization using dialysis. The presence of tannic acid allowed obtaining stable hydrogel materials with better mechanical properties. Tannic acid was released from matrices gradually and not rapidly. The antioxidant properties of the obtained hydrogels increased over the course of their incubation in culture media and were dependent on the concentration of tannic acid in the matrices. The obtained materials influenced dehydrogenase activity and the ATP level of pathogens. Additionally, the materials’ extracts improved the HaCaT cells’ viability. Therefore, the obtained hydrogels seem to be promising biocompatible materials which display antimicrobial properties.

In this study, sodium alginate-based thin films were modified by the addition of tannic acid. Materials were obtained by solvent evaporation. They were characterized by the observation of its morphology and its surface by scanning electron microscope and atomic force microscope. The thermal properties were studied by differential scanning calorimetry. The concentration of tannic acid released from the material was determined by the Folin–Ciocalteu method. The material safety for biomedical application was determined by the hemolysis rate study in contact with sheep blood as well as platelet adhesion to the material surface. Based on the obtained results, we assume that proposed films based on sodium alginate/tannic acid are safe and may potentially find application in medicine.

Recently, special attention has been paid to the development of active wound dressing materials based on biopolymers. Collagen is a natural polymer, which meets the requirements of modern materials for medical applications. However, despite its unique properties, collagen has no antimicrobial activity. In this work thymol was incorporated into collagen films to meet antimicrobial properties of the material. Thymol is a naturally occurring phenolic compound recognized as an antimicrobial agent. Collagen/thymol thin films were obtained through solvent evaporation using collagen solutions containing different amounts of thymol. The structure of the obtained materials was studied using FTIR-ATR spectroscopy. The inhibition ability on the growth of several strains of microorganisms was tested. The standard ISO 22196:2007 was used to define the bactericidal properties of the material. The growth of the following bacteria on the collagen/thymol films was studied: Escherichia coli , Pseudomonas aeruginosa , Staphylococcus aureus , Bacillus subtilis , Enterobacter aerogenes, Candida albicans . The results showed that the growth of Staphylococcus aureus was the most inhibited compared to the other tested strains. Collagen/thymol material is more efficient against pathogens through direct contact compared to the diffusion of thymol from the material. In general, the thymol addition inhibits biofilm formation on the collagen surface.

Scaffolds based on chitosan/tannic acid cross-linked by glyoxal were obtained by the freeze-frying method. Bio-studies were carried out to consider the safety of material used in medical applications. Thereby, the blood and PDLSC cell compatibility studies were carried out. The results showed that glyoxal is safe cross-linker for chitosan/tannic acid mixtures. Cross-linked scaffolds were nonhemolytic. Moreover, cells cultured on the scaffolds with glyoxal showed higher metabolic activity for 80CTS/20TA composition than others. The current findings allow for the medical application of the proposed materials as wound dressings.

Sodium alginate and tannic acid are natural compounds that can be mixed with each other. In this study, we propose novel eco-friendly hydrogels for biomedical applications. Thus, we conducted the following assessments including (i) observation of the structure of hydrogels by scanning electron microscope, (ii) bioerosion and the concentration of released tannic acid from subjected material, (iii) dehydrogenase activity assay to determine antibacterial activity of prepared hydrogels, and (iv) blood and cell compatibility. The results showed that hydrogels based on sodium alginate/tannic acid exert a porous structure. The immersion in simulated body fluid (SBF) results in the biomineralization process occurring on their surface while the bioerosion studies revealed that the addition of tannic acid improves hydrogels&rsquo, stability proportional to its concentration. Besides, tannic acid release concentration depends on the type of hydrogels and the highest amount was noticed for those based on sodium alginate with the content of 30% tannic acid. Antibacterial activity of hydrogels was proven for both Gram-negative and Gram-positive bacteria, the hemolysis rate was below 5% and the viability of the cells was elevated with an increasing amount of tannic acid in hydrogels. Collectively, we assume that obtained materials make the imperative to consider them for biomedical applications.