Improvement of bioactivity with dual bioceramic incorporation to nanofibrous PCL scaffolds

Abstract

Bone tissue injuries, diseases or related clinical interventions require bone tissue engineering (BTE) approaches for regeneration of large bone defects, especially for compromised situations. Most BTE applications in literature focused on composites of polymers with a single type of bioceramic. However, native bone matrix has various inorganic components. Accordingly, this study aimed to investigate the use of dual bioceramics in BTE scaffolds prepared by wet-electrospinning of Poly-caprolactone (PCL) and bioceramics; hydroxyapatite (HA), carbonated hydroxyapatite (CHA) and akermanite (AKR). After physicochemical characterizations of single and dual bioceramic-discs, it was found that AKR component should be at most 10% and thus, fibrous 3D composite scaffolds (PCL/HA; PCL/CHA; PCL/90HA/10AKR; PCL/90CHA/10AKR) were prepared. Scaffolds were then compared for degradation, swelling and microstructure properties. PCL/CHA, PCL/HA/AKR and PCL/CHA/AKR scaffolds improved apatite formation and presence of CHA, AKR or both in scaffolds increased Ca/P precipitation compared to HA involving scaffolds. Specifically, when two bioceramics were introduced, there was a noticeable increase in mineralization. No significant weight change was detected for scaffolds after two weeks of incubation. Presence of bioceramics in scaffolds significantly reduced swelling of PCL scaffolds with PCL/90HA10AKR and PCL/90CHA10AKR having higher swelling results than PCL/HA and PCL/CHA, respectively. Additionally, scaffolds with dual bioceramics (90HA10AKR, 90CHA10AKR) had higher cell proliferation for bone cells (Saos-2). In terms of osteogenic activity all groups showed increased ALP activity at 14 days compared to 7 days with PCL/CHA scaffolds having the highest value. Results suggests that newly developed PCL/90HA10AKR and PCL/90CHA10AKR composites hold potential for bone tissue engineering applications.