Modification and Characteristics of Biofunctional Properties of Collagen-Containing Xerogels for Medical Purposes: Results of the Experimental Study

INTRODUCTION. Development and improvement of methods and materials used in regenerative medicine for non-drug stimulation of tissue repair will solve a number of clinical problems associated with diseases that impede the normal process of reparative regeneration, such as diabetes, cardiovascular diseases and metabolic disorders. Collagen and its derivatives are already used as components of biomaterials for medical purposes. However, low mechanical strength, rapid biodegradation in physiological environments and weak resistance to enzymes limit the scope and effectiveness of their medical and biological applications. AIM. The aim of the study is to evaluate the effect of carboxylic acids on the strength, biodegradability and biocompatibility of collagen xerogel, in vitro. MATERIALS AND METHODS. The mechanical characteristics of the materials were assessed using a TA.XTplus texture analyzer. The biocompatibility of the materials was assessed by light and fluorescence microscopy using fluorescent dyes (DAPI, Rhodamine) and a Calcein AM (CCK-F) cell viability kit. RESULTS AND DISCUSSION. A xerogel based on denatured collagen with high strength characteristics was created. The parameters of heat treatment and concentrations of carboxylic acids were selected to stabilize the mechanical properties of the hydrogel. It was found that the introduction of citric acid into the hydrogel from denatured collagen and subsequent high-temperature treatment allows to increase the mechanical strength of the xerogel from 59 ± 3 to 82 ± 13 kPa. In addition, the introduction of citric acid into the composition of the xerogel increases its resistance to biodegradation by more than three times. The microenvironment created by the xerogel containing citric acid does not have a cytotoxic effect, but it does inhibit proliferation of fibroblasts. CONCLUSION. The results of the in vitro study showed that the obtained material can become a promising platform for use both as an extracellular scaffold and as an independent biomaterial for filling the volume of tissue lost as a result of surgery or injury.