In Vivo feature of the regenerative potential of chitosan and alginate based osteoplastic composites doped with calcium phosphates, zinc ions, and vitamin D2

Purpose: In vivo comparison of the regenerative potential of two calcium phosphate-biopolymer osteoplastic composites: & acy;) based on alginate (Alg) and hydroxyapatite (HA) - Alg/HA/CS/Zn/D2, b) based on chitosan (CS) and brushite (DCPD) - CS/DCPD/D2. Materials and methods: 36 white male laboratory rats aged six months were used. A defect to the bone marrow canal in the middle of the femur diaphysis was made with a dental bur of 2 mm. The bone defect healed under the blood clot (control) in the different animal groups and was filled with Alg/HA/CS/Zn/D2 and CS/DCPD/D2. The regeneration of the bone defect was studied on the 30th, 90th, and 140th days by computer tomography (CT). Results: On the 30th day, all groups' implantation site optical density (OD) was significantly lower than that of the adjacent maternal bone (MB). Intensity of bone formation for Alg/HA/CS/Zn/D2 exceeds CS/DCPD/D2. On the 90th day, the bone trauma site OD with Alg/HA/CS/Zn/D2 (1725.4 +/- 86 HU) and CS/DCPD/D2 (1484.9 +/- 69 HU) exceeded the OD of the control (942.5 +/- 55 HU). On the 140th day, the OD of Alg/HA/CS/Zn/D2 and CS/DCPD/D2 implantation sites was higher than Control and MB OD. Visually, the area of the past injury with the Alg/HA/CS/Zn/D2 could be detected only by the presence of an endosteal bone callus and in the case of CS/ DCPD/D2 - by the shadow of the remaining biomaterial in the bone marrow canal. Conclusions: According to CT data, Alg/HA/CS/Zn/D2 and CS/DCPD/D2 contribute to the complete healing of the femoral diaphysis defect in 140 days, but the regenerative potential of Alg/HA/CS/Zn/D2 from 30 days to 140 days is higher than CS/DCPD/D2 biomaterial.