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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.

The aim of this study was to isolate biofilm-forming bacteria that are capable of degrading polyhydroxybutyrate (PHB) with polyhexamethylene guanidine (PHMG) derivatives. The three types of derivatives incorporated in PHB and their concentration affected the biodegradability of the tested films in both water and compost. The PHMG derivative granular polyethylene wax at the highest concentration significantly inhibited BOD in both environments. At the same time, in water, PHB with PHMG stearate at 1% concentration was also found to inhibit biodegradation but to a lesser extent than PHMG polyethylene wax granulate. Analyzing the values of biofilm abundance and their hydrolytic activity in water, low concentrations of PHMG derivatives (0.2 and 0.6%) slightly inhibited biofilm abundance on the surface of the tested composites. Only granular polyethylene wax PHMG (at 1% concentration) significantly reduced biofilm formation and hydrolase activity in the compost to the greatest extent. Bacteria from biofilm were isolated and identified. Based on the 16S rRNA gene sequence, the strains belong to Bacillus toyonensis HW1 and Variovorax boronicumulans HK3. Introduction of the tested isolates to the environment can enhance composites degradation. However, this requires further research.

High utilization of thermoplastic polymers with low degradation rates as packaging materials generates a large amount of waste. Therefore, it should be replaced by natural polymers that can be degraded by microorganisms. In this paper, chitosan (CTS)/tannic acid (TA) materials in the weight ratios of 80CTS/20TA and 50CTS/50TA were prepared as potential packaging materials. The results showed that these materials were similarly degraded in soil and compost. However, in comparison to 50CTS/50TA, 80CTS/20TA was slightly better degraded in soil. After 14 days of biodegradation, the chemical structure of materials was changed resulting from adhesion of the microorganisms. The smallest changes were observed on 80CTS/20TA film. Bacterial species were collected and identified from materials after the degradation process. Microorganisms with the highest hydrolytic activity were chosen for the degradation study. Biodegradation and hydrolytic activity were observed only in a few strains, which indicate difficulties in material degradation. Soil bacteria degraded the films better than bacteria isolated from the compost. This study showed also that consortia of bacteria added to soil and compost had a positive effect on the biodegradation of the tested materials and increased the biodegradation of these materials in the studied environments.

Collagen possesses unique properties, e.g., biocompatibility, biodegradability, and non-toxicity. However, collagen material degrades too quickly and has low mechanical properties. One of the methods of polymers' modification is mixing them to obtain blends. In this study, the influence of $\beta$-glucan for collagen material was analyzed. The interaction between the functional groups of the polymer was analyzed by ATR-FTIR (attenuated total reflection-fourier transform infrared) spectroscopy. The influence of $\beta$-glucan on mechanical properties was evaluated. The surface properties of materials were assessed using contact angle measurements and the topography of materials was evaluated by AFM (atomic force microscope). The structure of materials was analyzed according to SEM (scanning electron microscopy) pictures. Moreover, the DPPH-free radicals' scavenging ability and biocompatibility against erythrocytes and HaCaT cells were evaluated. Collagen and $\beta$-glucan were bound together by a hydrogen bond $\beta$-glucan addition increased the roughness of the surface of the film and resulted in a more rigid character of the materials. A small addition of $\beta$-glucan to collagen provided a more hydrophilic character. All the materials could swell in in vitro conditions and showed antioxidant activity. Materials do not cause erythrocyte hemolysis. Finely, our cytotoxicity studies indicated that $\beta$-glucan can be safely added at small (10\% or less) quantity to collagen matrix, they sufficiently support cell growth, and the degradation products of such matrices may actually provide some beneficial effects to thesurrounding cells/tissues.

The interests in the biomedical impact of tannic acid (TA) targeting production of various types of biomaterials, such as digital microfluids, chemical sensors, wound dressings, or bioimplants constantly increase. Despite the significant disadvantage of materials obtained from natural-based compounds and their low stability and fragility, therefore, there is an imperative need to improve materials properties by addition of stabilizing formulas. In this study, we performed assessments of thin films over TA proposed as a cross-linker to be used in combination with polymeric matrix based on chitosan (CTS), i.e. CTS/TA at 80:20 or CTS/TA at 50:50 and poly(ethylene glycol) (PEG) at the concentration of 10% or 20%. We evaluated their mechanical parameters as well as the cytotoxicity assay for human bone marrow mesenchymal stem cells, human melanotic melanoma (MNT-1), and human osteosarcoma (Saos-2). The results revealed significant differences in dose-dependent of PEG regarding the maximum tensile strength (σmax) or impact on the metabolic activity of tissue culture plastic. We observed that PEG improved mechanical parameters prominently, decreased the hemolysis rate, and did not affect cell viability negatively. Enclosed data, confirmed also by our previous reports, will undoubtedly pave the path for the future application of tannic acid-based biomaterials to treat wound healing.

Acrylic bone cements (BC) are wildly used in medicine. Despite favorable mechanical properties, processability and inject capability, BC lack bioactivity. To overcome this, we investigated the effects of selected biodegradable additives to create a partially-degradable BC and also we evaluated its combination with nanosilver (AgNp). We hypothesized that using above strategies it would be possible to obtain bioactive BC. The Cemex was used as the base material, modified at 2.5, 5 or 10 wt% with either cellulose, chitosan, magnesium, polydioxanone or tricalcium-phosphate. The resulted modified BC was examined for surface morphology, wettability, porosity, mechanical and nanomechanical properties and cytocompatibility. The composite BC doped with AgNp was also examined for its release and antibacterial properties. The results showed that it is possible to create modified cement and all studied modifiers increased its porosity. Applying the additives slightly decreased BC wettability and mechanical properties, but the positive effect of the additives was observed in nanomechanical research. The relatively poor cytocompatibility of modified BC was attributed to the unreacted monomer release, except for polydioxanone modification which increased cells viability. Furthermore, all additives facilitated AgNp release and increased BC antibacterial effectiveness. Our present studies suggest the optimal content of biodegradable component for BC is 5 wt%. At this content, an improvement in BC porosity is achieved without significant deterioration of BC physical and mechanical properties. Polydioxanone and cellulose seem to be the most promising additives that improve porosity and antibacterial properties of antibiotic or nanosilver-loaded BC. Partially-degradable BC may be a good strategy to improve their antibacterial effectiveness, but some caution is still required regarding their cytocompatibility. Statement of significance The lack of bone cement bioactivity is the main limitation of its effectiveness in medicine. To overcome this, we have created composite cements with partially-degradable properties. We also modified these cements with nanosilver to provide antibacterial properties. We examined five various additives at three different contents to modify a selected bone cement. Our results broaden the knowledge about potential modifiers and properties of composite cements. We selected the optimal content and the most promising additives, and showed that the combination of these additives with nanosilver would increase cements` antibacterial effectiveness. Such modified cements may be a new solution for medical applications.

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.

Background: Essential oils (EOs) from Artemisia dracunculus L. and Origanum vulgare L. ssp. hirtum were obtained and the qualitative and quantitative chemical composition of the extracts was investigated. The insecticidal activity of EOs against the larval stages of Alphitobius diaperinus (Panzer) was studied. Moreover, the antimicrobial activity of these oils against pathogens transmitted by this pest was also investigated.; Results: The obtained results indicate the possibility of using Greek oregano EO with a high content of carvacrol as a feed additive in poultry nutrition. The use of the Greek oregano oil at 1% (w/w) dose showed stronger reduction of body weight gain of stage IV larvae. Their body mass was only 10.92% of the control. Moreover, EOs from O. vulgare strongly inhibited the growth of tested bacterial strains as well as Candida albicans.; Conclusion: Greek oregano EO may be a good alternative to antibiotic growth promoters and coccidiostats whose use in feeding farm animals has been prohibited since January 2006 under European Union directives. The introduction of O. vulgare L. ssp. hirtum EO into the premises of farm and poultry houses may help to improve sanitary conditions and control of the lesser mealworm inhabiting these buildings. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

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.

Nanostructured coatings on cardiovascular stent surfaces can significantly alter the blood cell response and can effectively tailor the anti-thrombotic potential of the surfaces. The present work investigates the specific impact of physico-chemical characteristics of a hydrothermally treated beta-type Ti 29Nb (at.%) alloy. Surface tailored nanostructured titania surfaces on TiNb alloy and the ensuing blood compatibility have been analyzed. Nanograss-like structures were successfully fabricated on TiNb alloy surfaces via a facile hydrothermal technique. The developed structures exhibited nanotopographies and composed predominantly of anatase titania. Wettability studies revealed the superhydrophilic property of the developed nanograss structures and these structures exhibited reduced hemolysis rates and meagre platelet adhesion and activation. The underlying mechanism of these characteristics is explained in terms of morphology, roughness and chemical composition. In conclusion it is demonstrated that the developed superhydrophilic surface coating can provide new opportunity for blood contacting implant applications.

In this study, surface and biological properties of collagen/thymol materials were evaluated. Antimicrobial properties of materials were evaluated by measuring ATP level and enzymatic activity of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa after the contact with materials. Surface properties were analyzed by AFM spectroscopy and contact angle measurements. Materials were characterized by rough surface and hydrophobicity of materials increase with increasing thymol amount. Prepared materials were permeable for gaseous exchange, but sufficiently prevented from the secondary infection. Collagen/thymol caused haemolysis of blood cells, but changing the non-ionic surfactant may improve the blood biocompatibility parameter.

Essential oils (EOs) from Artemisia dracunculus L. and Origanum vulgare L. ssp. hirtum were obtained and the qualitative and quantitative chemical composition of the extracts was investigated. The insecticidal activity of EOs against the larval stages of Alphitobius diaperinus (Panzer) was studied. Moreover, the antimicrobial activity of these oils against pathogens transmitted by this pest was also investigated.The obtained results indicate the possibility of using Greek oregano EO with a high content of carvacrol as a feed additive in poultry nutrition. The use of the Greek oregano oil at 1% (w/w) dose showed stronger reduction of body weight gain of stage IV larvae. Their body mass was only 10.92% of the control. Moreover, EOs from O. vulgare strongly inhibited the growth of tested bacterial strains as well as Candida albicans.Greek oregano EO may be a good alternative to antibiotic growth promoters and coccidiostats whose use in feeding farm animals has been prohibited since January 2006 under European Union directives. The introduction of O. vulgare L. ssp. hirtum EO into the premises of farm and poultry houses may help to improve sanitary conditions and control of the lesser mealworm inhabiting these buildings. © 2017 Society of Chemical Industry.

Natural polymers can be used to produce materials for biomedical application. In this study, polymeric blends based on chitosan and tannic acid in the form of thin films were obtained. They were characterized for the potential application as wound dressings. Thereby, the thermal stability, maximum tensile strength and water vapor permeability were measured. Moreover, the blood compatibility was determined as the erythrocytes hemolysis rate. The results showed that the addition of tannic acid to chitosan improves the physicochemical properties of the film. The maximum tensile strength and water vapor permeation rate were improved. The hemolysis rate was higher for films with a higher amount of tannic acid than for those containing pure chitosan, however, the value was below 5%, which allows for the medical application of the proposed materials as wound dressings.