Abstract
In order to accelerate biofixation, tested implants were impregnated with a copolymer of collagen with proteoglycan. Additionally, we tested polyethylene (PE) and C-C-composite.
We evaluated their biocompatibility on cell cultures of fibroblasts and investigated the reactions of neighbouring tissues to the implantation of these materials into the subcutis of laboratory sewer rats and paraosseally on the femur of farmyard pigs (Sus domesticus). We prepared polyethelene with either a hydrophobic or hydrophilic surface and the composite C-C.
Before implantation in the experimental animal they were coated with a film of the copolymer collagen-proteoglycan. We tested in vitro, how these materials affected cellular proliferation and cytokine expression.
In vivo we investigated the biological fixation of these materials in sewer rats and pigs. In these tests a certain proportion of the implants made of these materials was coated with the copolymer collagen-proteoglycan.
The collagen was obtained from calf leather (fraction ISC 40), the proteoglycan was isolated from calf cartilage with 2M GuHCl. While in vitro hydrophilic PE most strongly induced IL8 formation, hydrophobic PE stimulated TNF - formation.
In the subcutis of laboratory sewer rats all the materials were biocompatible; on the 10th day after implantation into the subcutis differences between individual samples were minimal. The coating of the composite C-C with copolymer collagen-proteoglycan reduced the number of smear particles in the vicinity.
In cases of paraosseal implantations to pigs after two months we found centrally cellular connective tissue and on the outside of the implant woven bone. After six weeks the implants were very firmly fixed to the bone, from which they could be separated only with great difficulty.
Coating the samples with CCP stimulated the formation of dystrophic calcifications.