In Vitro and In Vivo Evaluation of Customized Polycaprolactone Tricalcium Phosphate Scaffolds for Bone Tissue Engineering

Abstract

Degradation studies of scaffolds play an important role in bone tissue engineering. After initially being subjected to hydrolytic and enzymatic treatment, the degradation kinetics of untreated, sodium hydroxide-treated, and lipase-treated polycaprolactone-20% tricalcium phosphate (PCL-TCP) scaffolds at similar porosity (85%) were conducted in vitro when immersed in culture medium, and in vivo when implanted in the subcutaneous back of rats for up to 24 weeks. At selected time points, samples were retrieved and characterized. Histology was also performed for the in vivo group. Overall the results demonstrated that the NaOH-treated scaffolds achieved the most favorable mechanical properties when higher porosity values were targeted. PCL-TCP scaffolds and sheets were then further studied in a micropig mandibular defect model and analyzed for up to 6 months. Greater bone formation was detected in defect sites augmented with autografts and collagen membranes as compared to PCL-TCP scaffolds which were about 64% efficient.