Enhanced bone implant with porous polypropylene matrix coated with chitosan and hydroxyapatite

Porous polymer matrix based on functionalized polypropylene coated with chitosan and hydroxyapatite was prepared to evaluate its body response and establish its ability to induce osteointegration and/or osteoconduction. 12 Sprague-Dawley rats were divided into 6 groups corresponding to 0, 1, 2, 4, 8 and 16 weeks of healing; a 5x1 mm bone defect was created in the proximal diaphysis of both tibiae. In the right member the composite to evaluate was introduced and the left member was used as control. Animals were sacrificed by CO2 chamber and a radiographic and histological study was done. The implanted composite showed no evidence of foreign body reaction from the first week and maintained close contact with newly formed bone tissue. During the first two weeks a periosteal reaction penetrating the implant pores was observed. Osteogenic buds observed as mesenchymal cells condensations highly vascularized and newly trabecular bone formations were found within the implant pores. New bone formation was observed until the eighth week after implantation when morpho-structural adaptation began. We concluded this matrix coated with chitosan and hydroxyapatite exhibited osteointegrated properties because it’s structurally binding to bone and osteoconductive properties due to adhesion, proliferation, and differentiation of the osteoblastic cells within their pores.