Tetracycline hydrochloride-containing poly (ε-caprolactone)/poly lactic acid scaffold for bone tissue engineering application: in vitro and in vivo study

In the current study, tetracycline hydrochloride (TCH), an antibiotic against most of the medically relevant bacteria, was incorporated into poly (ε-caprolactone)/poly lactic acid solution in order to develop a composite scaffold with both antibacterial and osteoinductive properties for the repair of infected bone defects. The composite scaffolds were produced from poly (ε-caprolactone) (PCL) and poly lactic acid (PLA) solution (1:1 (w/w)) incorporated with 3, 5, and 10% (w/w) of TCH by thermally induced phase separation technique. The scaffolds were evaluated regarding their morphology, wettability, porosity, degradation, mechanical properties, and cellular response. The scaffold containing 10% of TCH (PCL/PLA/TCH10%) was chosen as the optimum scaffold for further investigation in a rat femoral defect model. The study showed that after eight weeks, the bone formation was relatively higher in PCL/PLA/TCH10%-treated group with completely filled defect when compared with control (PCL/PLA scaffold without TCH). Histopathological evaluation showed that the defect in PCL/PLA/TCH10%-treated group was fully replaced by new bone and connective tissue. Our results provide evidence supporting the possible applicability of TCH-containing scaffolds for successful bone regeneration.