Human Hair Keratin Artificial Tendon Materials Biocompatibility

During the last years, the requirement for biocompatibility of biomaterial becomes higer and the evaluation of biocompatibility of biomaterials become more and more important as the progress in biomaterials and tissue engineering is made. Human Hair Keratin Artificial Tendon (HHKAT) is a new kind of biodegradable material, invented by The First Military Medical University. The priiminary basic and clinic study has found that HHXAT can be sequencely absorbed and induce neotendonization, without the disadvantage of strength attenuation and inflammatory reaction of nonbiodegradable materials. It has great prospect in clinic appliance as a substitute of tendon and ligament. So we evaluate the biocompatibility of FIFIKAT material, expect to provide some biological basement for its further use. The present study delineate the two relative issues. The results are as follows: Part I In vitro experimental study on biocompatibility of HHKAT material The biocompatibility of HHKAT material in vitro was evaluated by extract liquid and direct contact assay. Different concentrations of (1 0O%,50%, 10%) extract liquid of 1-IHKAT material were added to human embryonic tendon cell (HETC), evaluated for biocompatibility at 1,3,5,7 day. The influence of extract liquid of HHLKAT material on morphologic, metabolic, cell membrane, proliferation, and express of collagen I of HETC.was investigated by convert microscope, MTT colorimetric assay, LDH filter assay, examination of cell protein, and Immunocytochemistry of collagen I. By observation of the co-culture of HETC and HHXAT, the adhesion, proliferation and ultrastructure of HETC surrounding HHKAT material were studied. Results showed that: various concentration extract liquid of HHKAT has no influence on morphologic, metabolic, cell membrane, proliferation, and express of collagen I of HETC. According to ISO criterion, the cytotoxicity is under I stage. Results demonstrate that HHKAT material is a biomaterial with good biocompatibility in vitro. Part II The investigation of degradation and histologic biocompatibility of various group of HIHKAT in rabbit body The period and process of degradation of various group of HHKAT were studied by transplanting them into spine muscle of rabbit. Measuring the size of envelop, the inflammation cell and ultrastructure, to investigate the influence of HHKAT on surrounding tissue during transplantation and degradation, to provide experimental basement for appliance of HHKAT in clinic and scaffold in the tissue engineering tendon. Results showed: various group of HHKAT has different period and process of degradation in body. The F group has shortest degradable time, which showed evidence of degradation at 6 week, degradation accelerate at 12 week, has been absorbed completely at 24 week, while Z group has long degradable time, which has evidence of degradation at 24 week. Normal hair has not been found degradation in 24 week. At early stage of HI-IKAT transplantatation, the thickness of envelop, the inflammation cell and ultrastructure around it is similar. At midium stage, F group begin to show evidence of degradation, its envelop is thiner than that at the early time, most of the inflammation cell are macrophage and degradable particle can be seen in plasma of macrophage, proving that macrophage play a role in absorption of HHKAT. The change of Z, 0 group is similar, where most inflammation cell is fibroblast, the envelop become thicker than that at the earl...