Biomechanical investigation on host response of acellular dermal matrix in lamellar corneal transplantation

The biocompatibility, biological changes and tissue structure of acellular dermal matrix (ADM) in lamellar corneal transplantation (LCT) as a substitute are experimentally investigated in order to evaluate its possibility as a supporting material in corneal tissue engineering. The microstructure of ADM was observed with light microscope (LM), fluorescence microscope, polarizing microscope, and transmission electron microscope (TEM). In the implantation experiment, the ADM was processed with 3 different methods and implanted into rabbit corneal stroma. The ocular surface condition was observed with slit lamp microscope (SLM) postoperatively. The rabbits were sacrificed and morphology structures of the corneal grafts were studied by LM and polarizing microscope at 1 week, 4 weeks, 12 weeks and 24 weeks after transplantation. It was found that the ADM were composed mainly of Type-I and III collagens organized loosely and disorderly. No cellular structure was observed. There were inflammatory responses after implantation. Some implants turned to be transparent. Histological study evidenced both the growth of cells into the implant and the reconstruction collagen fiber. The results showed that the ADM with compact structure and proper pretreatment could stably exist in corneal stroma after implantation and, therefore, could be used as a potential scaffold in corneal tissue engineering.