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EN
Chitosan is widely used to prepare films, hydro-gels, cryogels, sponges, fibers and other various biomaterials used in the tissue engineering field. It is one of the best processable polysaccharides used in biomedicine. However, its stability is generally lower as compared with others, due to its pH sensitivity and hydrophilic character. Using chitosan in combination with agarose may not only improve chemical and mechanical properties of the resultant material (by the formation of a biocomposite), but also lead to the formation of a gel imitating physical attributes of the extracellular matrix. Moreover, the combination of these two polysaccharides has a promising ability to improve the stability of chitosan and to increase fibroblasts’ affinity to agarose. Characteristic advan-tageous features of these natural polymers raise a wide interest in tissue engineering. The aim of this study was to develop and optimize a new method to produce a highly biocompatible foam-like chitosan/agarose wound dressing for skin healing applications. The production process optimization helped to obtain the absorbent foam-like biomaterial which is non-toxic to skin fibroblasts and does not conduce their adhesion. Employing sodium bicarbonate as the main agent in the foaming reaction not only led to obtaining the foam-like structure but also neutralized the acidic pH, making the material non-toxic and non-irritating to the skin. In conclusion, the new foam-like biomaterial has great potential for biomedical applications as the wound dressing accelerating the healing process of the damaged tissues.
EN
The use of liquid rubber as a component of light-cured dental composites is one of the methods of increasing their fracture toughness. It also reduces polymerization shrinkage and offers the potential to lower water sorption. The aim of the study was to evaluate the miscibility of liquid rubber in composite matrix resins as well as changes in the wettability and surface free energy (SFE) values of commercial lightcuring composites after their modification with liquid rubber. The research materials were Flow Art and Boston (Arkona) light-cured composites and resin mixtures used in their production. Liquid rubber Hypro 2000X168LC VTB (Huntsman Int.) was used as a modifier. The solubility of liquid rubber was assessed under light microscopy. The contact angle and SFE measurements were made on a DSA30 goniometer (Kruss) using water and diiodomethane. It was found that the liquid rubber solubility depended mainly on the viscosity of the resin, which was related to the amount of BisGMA. The resulting mixture showed good temporal stability without larger domains. The curing process released the liquid rubber as a separate phase formed as spherical domains. The morphology of these domains was homogeneous and their size did not exceed 50 µm in diameter. The presence of liquid rubber in modified composites increased their hydrophobicity and reduced the surface free energy value. The obtained properties might help to reduce the formation of bacterial biofilm on dental fillings.
EN
Since it is known that various cell lines may ex-press different behaviours on the scaffolds surface, a comprehensive analysis using various cellular mo-dels is needed to evaluate the biomedical potential of developed biomaterials under in vitro conditions. Thus, the aim of this work was to fabricate bone scaffolds composed of a chitosan-agarose matrix reinforced with nanohydroxyapatite and compare the biological response of two cell lines, i.e. mouse calvarial preosteoblasts (MC3T3-E1 Subclone 4) and human foetal osteoblasts (hFOB 1.19). Within this study, the osteoblasts number on the scaffold surface and the osteogenic markers level produced by MC3T3-E1 and hFOB 1.19 cells were determined. Furthermore, changes in calcium and phosphorous ions concentrations in the culture media dedicated for MC3T3-E1 and hFOB 1.19 were estimated after the biomaterial incubation. The obtained results proved that the fabricated biomaterial is characterized by biocompatibility and osteoconductivity since it favours osteoblasts attachment and growth. It also supports the production of osteogenic markers (collagen, bALP, osteocalcin) by MC3T3-E1 and hFOB 1.19 cells. Interestingly, the developed biomaterial exhibits different ion reactivity values in the two culture media dedicated for the mentioned cell lines. It was also revealed that mouse and human osteoblasts differ in the cellular response to the fabricated scaffold. Thus, the use of at least two various cellular models is recommended to carry out a reliable biological characterization of the novel biomaterial. These results demonstrate that the tested bone scaffold is a promising biomaterial for bone regeneration applications, however further biological and physicochemical experiments are essential to fully assess its biomedical potential.
EN
The problem of treating chronic wounds is widespread throughout the world and carries a huge cost. Biomaterials engineering tries to solve this problem by creating innovative bioactive dressings dedicated to specific types of wounds. Both synthetic and natural polymers are the main base to produce wound dressings. Biopolymers have the advantage over synthetic polymers by being more biocompatible, non-toxic, biodegradable, and eco-friendly. The aim of this work was to produce a bioactive biomaterial based on natural polymers with potential applications to manage chronic highly exuding and infected wounds. A newly developed method for chemical synthesis of the curdlan/agarose biomaterial at high temperature combined with freeze-drying process resulted in a superabsorbent dressing material with antibiotic immobilized. The obtained biomaterial was subjected to basic microbiological in vitro tests and a cytotoxicity assay according to ISO 10993-5. Moreover, the experimental treatment of the infected wound in a veterinary patient was performed using the developed material. Based on the conducted research, it was proved that the produced dressing is not toxic to normal human skin fibroblasts. An additional advantage of the biomaterial is its ability to inhibit the growth of harmful microorganisms, such as Staphylococcus aureus and Pseudomonas aeruginosa. Furthermore, the experimental treatment confirmed the validity of using the produced biomaterial as a dressing dedicated to the treatment of difficult-to-heal infected wounds. To summarize, the produced biomaterial possesses great potential to be used as a wound dressing for infected wounds.
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