Chitosan is an environmentally friendly agent that is used to achieve the antimicrobial properties of textiles. Nowadays, the binding of chitosan to the textiles has been thoroughly researched due to the increasing demands on the stability of achieved properties during the textile care processes. Most crosslinking agents for chitosan are not safe for humans or environment, such as glutaric aldehyde (GA) and formaldehyde derivatives. Eco-friendly polycarboxyilic acids (PCAs) are usually used in after-treatment. In this work, chitosan powder was dissolved in citric acid with sodium hydrophosphite (SHP) as a catalyst. Standard cotton (CO) and polyester/cotton (PES/CO) fabrics were pretreated in 20% NaOH, similar to mercerization, in order to open the structure of the cotton fibers and hydrolyze polyester fibers, continued by finishing in the gelatin chitosan bath. Afterwards, the hot rinsing process, followed by drying and curing, closed the achieved structure. The main objective was to achieve durable antimicrobial properties to multiple maintenance cycles CO and PES/CO fabric in order to apply it in a hospital environment. The characterization of fabrics was performed after treatment, first and fifth washing cycles according ISO 6330:2012 by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR-ATR), electrokinetic analysis (EKA), by the determination of tensile properties and mechanical damage (wear), and the antimicrobial activity. The application of 20% NaOH led to the swelling and mercerization of cotton cellulose, and hydrolysis of polyester, resulting in better mechanical properties. It has been confirmed that the chitosan particles were well implemented into the cotton fiber and onto to the polyester component of PES/CO blend. The presence of chitosan was confirmed after five washing cycles, but in lower quantity. However, achieved antimicrobial activity is persistent.
Modified alginates have a wide range of applications, including in the manufacture of dressings and scaffolds used for regenerative medicine, in systems for selective drug delivery, and as hydrogel materials. This literature review discusses the methods used to modify alginates and obtain materials with new or improved functional properties. It discusses the diverse biological and functional activity of alginates. It presents methods of modification that utilize both natural and synthetic peptides, and describes their influence on the biological properties of the alginates. The success of functionalization depends on the reaction conditions being sufficient to guarantee the desired transformations and provide modified alginates with new desirable properties, but mild enough to prevent degradation of the alginates. This review is a literature description of efficient methods of alginate functionalization using biologically active ligands. Particular attention was paid to methods of alginate functionalization with peptides, because the combination of the properties of alginates and peptides leads to the obtaining of conjugates with properties resulting from both components as well as a completely new, different functionality.
On the basis of models developed and experimental studies, the impact of a compression garment on average and local changes in unit pressure was analysed. The study was based on the analysis of the results of 3D scans of selected parts of female and male bodies. It was found out that surface pressure exerted by the compression garment leads to some changes in the geometry of body circumferences and in their lengths and, consequently, to a change in the average pressure value, as well as local changes along the circumference. The main purpose of this work was to estimate the size of these changes in the example of selected parts of female and male bodies.
Derived from chitin, chitosan is a natural polycationic linear polysaccharide being the second most abundant polymer next to cellulose. The main obstacle in the wide use of chitosan is its almost complete lack of solubility in water and alkaline solutions. To break this obstacle, the structure of chitosan is subjected to modification, improving its physic-chemical properties and facilitating application as components of composites or hydrogels. Derivatives of chitosan are biomaterials useful for different purposes because of their lack of toxicity, low allergenicity, biocompatibility and biodegradability. This review presents the methods of chemical modifications of chitosan which allow to obtain tailor- made properties required for a variety of biomedical applications. Selected pharmaceutical and biomedical applications of chitosan derivatives are also highlighted. Possibility to manage waste from arthropod and crab processing is also emphasized.
In spite of intensively conducted research allowing for the development of more and more advanced wound dressing materials, there is still a need for dressings that stimulate not only reparative and regenerative processes, but also have a positive effect on infected and/or difficult-to-heal wounds. Porous dressing materials based on butyric-acetic chitin co-polyester containing 90% of butyryl and 10% of acetyl groups (BAC 90/10) can also be included in the group mentioned above. Two types of dressings were obtained by the salt leaching method, i.e. a porous sponge Medisorb R and Medisorb Ag with an antibacterial additive. The aim of the study was to evaluate biological effects of porous Medisorb R and Medisorb Ag dressings under in vitro and in vivo conditions. In an in vitro biodegradation test, no mass loss of Medisorb R dressing was observed within 14 days of incubation in physiological fluids at 37 °C. However, on the basis of the FTIR (Fourier Transform Infrared Spectroscopy) tests, surface degradation of Medisorb R dressing was observed. Additionally, the antibacterial activity of the porous Medisorb Ag dressing containing microsilver as an antibacterial additive was confirmed. The in vivo studies included inflammatory activity, skin irritation and sensitisation tests, as well an assessment of local effect after contact with subcutaneous tissue up to 6 months and skin wounds up to 21 days. In the in vivo tests, the dressings exhibited neither effects of skin irritation nor sensitisation. Under macroscopic examination, in full thickness defects of subcutaneous tissue and skin, the dressings caused wound healing with no inflammation, undergoing the most gradual biodegradation between weeks 4 and 8, and the observed differences were statistically significant. In the histological assessment, a weakened, limited inflammatory process associated with degradation of the material has been observed. The process of skin wound healing under Medisorb R dressing in the early period was accelerated compared to that observed in the control group with a gauze dressing.
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