Innovative biodegradable dibutyrylchitin dressing for the treatment of ulcers occurring during chronic venous insufficiency in patients with type 2 diabetes.

The aim of this study was to assess the course of the healing process following the use of dibutyrylchitin (DBC) dressing, a fully degradable material used in the treatment of ulcers which occur during chronic venous insufficiency common in patients suffering from type 2 diabetes. These diseases have a significant impact on the patients' standard of living, including the potential employment, and on the declining attendance at the current workplace. The implementation of this innovative therapeutic solution may positively affect the above-mentioned difficulties. An analysis of the healing process, following the application of the DBC dressing, was performed. Once the dressing was positioned on the wound, the analysis indicated that it underwent a process of degradation facilitated by the enzymes occurring naturally in the wound. When fully degraded, a further layer was applied. This process was repeated until the wound was fully healed. The study group consisted of 4 patients previously diagnosed with type 2 diabetes. During the observation period, the ulcers in all 4 cases had healed. The examined wound dressings adhered well to the wound surface and degraded within it. No side effects or adverse effects of the applied innovative therapy were observed. An addition of the biodegradable DBC dressing to the standard therapy procedure of ulcers occurring during chronic venous insufficiency among patients with type 2 diabetes indicate safe and effective treatment, which may have a direct reflection in the patient's professional capacity enhancement. It resulted in the complete healing of all ulcers in each of the observed cases. Int J Occup Med Environ Health. 2021;34(4):565-73.

Synthesis and physicochemical characterization of chitin dihexanoate--A new biocompatible chitin derivative--In comparison to chitin dibutyrate.

Chitin dihexanoate (DHCH) is the novel biocompatible and technologically friendly highly substituted chitin diester. Here we described optimization of DHCH and chitin dibutyrate (dibutyryl chitin, DBC) synthesis conditions (temperature and reaction time) to obtain desired polymers with high reaction yield, high substitution degree (close to 2) and appropriately high molecular weights. A two-step procedure, employing acidic anhydrides (hexanoic or butyric anhydride) as the acylation agent and methanesulfonic acid both as the catalyst and the reaction medium, was applied. Chemical structures of DBC and DHCH were confirmed by NMR ((1)H and (13)C) and IR investigations. Mechanical properties, thermogravimetric analysis, differential scanning calorimetry and biocompatibility (Neutral red uptake assay, Skin Sensitization and Irritation Tests) were assessed. Both polymers proved highly biocompatible (non-cytotoxic in vitro, non-irritating and non-allergic to skin) and soluble in several organic solvents (dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, acetone, ethanol and others). It is worth emphasizing that DHCH and DBC can be easily processed by solvent casting method and the salt-leaching method, what gives the opportunity to prepare highly porous structures, which can be further successfully applied as the material for wound dressings and scaffolds for tissue engineering.

Chitin dipentanoate as the new technologically usable biomaterial.

In this article, the synthesis of novel biopolymer, chitin dipentanoate (Di-O-Valeryl Chitin, DVCH) has been described. DVCH is a chitin derivative esterified with two valeryl groups at positions 3 and 6 of the N-acetylglucosamine units and it is soluble in common organic solvents like ethanol, methanol, acetone, dichloromethane, 1,2-dichloroethane, N,N-dimethylmethanamide, N,N-dimethylacetamide and ethyl acetate. Highly efficient synthesis (degree of esterification close to 2) of DVCH was achieved by employing a huge excess of valeric anhydride used as both the acylation agent and the reaction medium in the presence of perchloric acid as catalyst. Studies on the DVCH synthesis were aimed at finding optimal conditions (temperature, reaction time) to obtain DVCH with high reaction yield and desirable physicochemical properties. Biological data demonstrate that DVCH is non-cytotoxic in vitro and doesn't exert irritating or allergic effects to animal skin. Thanks to its filmogenic properties, it can be used to manufacture threads, foils, foams and non-woven materials. Moreover, DVCH can be easily processed by salt-leaching method to prepare highly porous structures exhibiting open-cell architecture, that can be further employed in wound dressing therapies and scaffolds for tissue engineering.