Importance of in situ thermal stability after surgical implantation of acellular scaffold.

Acellular scaffold is mainly composed of collagen, which is sensitive to temperature. The denaturation of collagen, whether immediately or lately after implantation will lead to profound influence on the micro-structure, biological activities of acellular scaffold, and tissue repairing process. However, the in situ thermal stability of acellular scaffold had rarely been investigated previously. In this study, the thermal stability of two acellular scaffolds, acellular bovine pericardium (S1) and acellular bovine dermis (S2), were investigated by in situ dura repairing experiments. The in situ dura repairing results showed that both samples could successfully integrate with Beagles' dura tissue after 1 month of implantation. S1 remained stable during the 6-month implantation period and no obvious denaturation or degradation was found. However, S2 remained stable only in the first month and denatured at the 2-month dissection timepoint. S2 was completely degraded at 6-month dissection timepoint and no new dura tissue was regenerated. The study showed that maintain thermal stability was important for acellular scaffold after surgical implantation. Denaturation of the acellular scaffold led to dramatic changes in the microenvironment of the host tissue. The long-term thermal stability should also not be ignored even though successful integration between the acellular scaffold and the defect tissue was established. Maintaining thermal stability of the acellular scaffold was conducive to tissue repairing or regeneration process.