Collagen and Mpcl-Tcp Scaffolds Induced Differential Bone Regeneration in Ovary-Intact and Ovariectomized Rats.

BACKGROUND:The data on biomaterial-mediated bone regeneration directly comparing commercially available scaffolds in aging and osteoporotic conditions remain sparse.OBJECTIVE:To investigate the effects of an absorbable collagen sponge (ACS) and a medical grade polycaprolactone-tricalcium phosphate (mPCL-TCP) scaffold on calvarial defect healing in ovary-intact and ovariectomized rats.METHODS:Forty-two, 5-month old female Sprague-Dawley rats were divided into sham (OVI) or ovariectomy (OVX) groups (n=21). When rats reached 6 months old, 7 mm diameter calvarial defects were created and treated, further dividing each group into blood clot control, mPCL-TCP, or ACS subgroups (n=7). After four weeks, the calvarial specimens were evaluated using micro-computed tomography for bone volume fraction (BVF), and histopathology.RESULTS:The effects of ovariectomy were confirmed by changes in body, uterine, and vaginal weight, and osteopenia in the femur. A significant increase in BVF was observed in ACS-subgroups compared with their respective control groups (p<0.05). Histopathological analysis revealed no cellular inflammatory infiltrate in any group. Fibrous tissue encapsulated the mPCL-TCP, while the ACS was well-integrated with the bone matrix. The OVX groups presented more osteoid and enlarged marrow cavities compared with the OVI groups.CONCLUSION:ACS scaffold enhanced calvarial bone regeneration in OVI and OVX rats after four weeks.