Morphological features of biodegradation and biocompatibility of combined polymeric matrices based on chitosan and hyaluronic acid

BACKGROUND: In the development of bioengineered materials used in reconstructive surgery, the tissue response to an implanted device plays a key role. Recent advances in the control of synthesis conditions have made it possible to produce materials with varying biodegradation and biocompatibility characteristics from the same polymer.

AIM: This work aimed to examine the pathomorphological features of biodegradation of combined polymeric films based on chitosan and hyaluronic acid obtained under different technological conditions.

METHODS: Subcutaneous implantation of 4 samples of two-component polymeric films was performed in 30 Wistar rats weighing 200–220 g. The films were produced from chitosan solutions with molecular weights of 500 and 900 kDa and hyaluronic acid with a molecular weight of 1300 kDa, followed by heat treatment (100 °C for 5 min). The type of biodegradation and biocompatibility was assessed on day 60 by histological analysis.

RESULTS: During the postimplantation period, there were no signs of acute toxicity, septic or allergic inflammation, or severe tissue deformation during scarring. Biodegradation of the chitosan–hyaluronic acid polyelectrolyte complex was found to proceed through a stage of simultaneous swelling and self-disintegration of the matrix. In response, reactive aseptic inflammation developed without the formation of multinucleated giant foreign body cells. Biocompatibility was manifested in two types of connective tissue growth: replacement throughout the entire thickness of the degrading matrix or formation of a peri-implant capsule clearly delineating the implanted material. It was demonstrated that increasing the molecular weight of chitosan and applying heat treatment to the film prolonged the biodegradation time of the entire two-component polysaccharide matrix.

CONCLUSION: The study demonstrated that modifying technological parameters allows the production of polymer films with an altered biodegradation pattern. The molecular weight of the polymer and the selected technological conditions for producing films based on the chitosan–hyaluronic acid polyelectrolyte complex act as regulators of the biodegradation rate of the polymer matrix in recipient tissues. This enables adaptation to specific clinical applications in tissue and organ reconstruction, where acceleration or deceleration of connective tissue development is required to promote restoration of native structure.