In vitro biocompatibility of polycaprolactone/hydroxyapatite nanocomposite membranes modified by oleic acid for bone regeneration

The bone defect is common in the orthopedic clinic, possibly due to trauma, tumor, or congenital diseases. Also, some patients with alveolar bone defects in the dental clinic result from the different proliferation speeds between soft and hard tissue. Biomaterials made of polymers and bioceramics have been developed to deal with these problems but mixing them directly can result in a low-mechanical strength complex. To solve this, we used oleic acid (C18) as a surfactant to improve the dispersity of hydroxyapatite (HA) in the polycaprolactone (PCL) matrix, and then immerse the material in a simulated biomineralization process. The results showed that the low crystallinity PCL formed an evenly distributed mineralized layer that had phosphate ions signal and a hydroxyapatite peak. The biocompatibility of the material was assessed using MC3T3 cells, and found that the PCL-HA membrane and PCL-C18-HA membranes had significant cell filopodia and lamellipodia. Additionally, the polycaprolactone/oleic acid/hydroxyapatite (PCL-C18-HA) membrane had the highest cell viability among all groups. The addition of C18 also decreased the platelets activation degree but had a significant difference in the reactive oxygen species (ROS) amount compared to the control, which requires further investigation. Overall, this study successfully fabricated a safe and promising polycaprolactone/hydroxyapatite/oleic acid nanocomposite membrane as a potential solution for bone biomaterials.