In vivo studies of novel scaffolds with tannic acid addition

Scaffolds based on chitosan, collagen, and hyaluronic acid supplemented with nano-hydroxyapatite and tannic acid were obtained by using the freeze-drying method. Biocompatibility was studied by the in vivo implantation into proximal tibial bones of rabbits. The bones were drilled and the biomaterial was introduced by filling the pre-drilled space. The histological studies were carried out three months after the implantation. The results showed low stability of the scaffolds based on chitosan, collagen, and hyaluronic acid supplemented with hydroxyapatite and tannic acid. The histological images showed the cetia and calcification centers. Moreover, the presence of thin-walled vessels filled with blood was noticed. Macrophages were observed in the area surrounding the implanted materials. The tissue response to the material implantation confirms that the tissue regeneration was initiated. The results showed satisfactory tissue response to the implanted scaffolds.