Electrospun poly(ε-caprolactone)/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) fibrous substrates for bone tissue engineering

Abstract

Fibrous substrates of the blend solutions of Poly(E-caprolactone) (PCL)/Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) in a mixture of chloroform and N,N-dimethylformamide (DMF) wer fabricated by electrospinning. The effect of the solution concntration on the morphology, mechanical integrity, and physicochemical properties of the obtained fibrous substrates was examined. The fibrous substrate prepared from 10 wt% PCL/PHBV solution exhibited the smoothest surface topography and the lowest static water contact angle, which have been reported to be suitable for cell growth. Taking into account the osteoconductivity of hydroxyapatite (HAp) and the osteoinductivity of bone proteins (i.e., type I collagen (COL), fibronectin (FN), and crude bone protein (CBP), HAp and bone proteins-loaded HAp nanoparticles were incorporated into the PCL/PHBV fibrous substrates. The potential use of these fibrous substrates as bone scaffolds was assessed in vitro with mouse-calvaria-derived preosteoblastic cells (MC3T3-E1) in terms of the attachment, proliferation, alkaline phosphatase (ALP) activity, and mineralization. Furthermore, the capability of the PCL/PHBV fibrous substrate as a drug carrier was also investigated by the incorporation of doxycycline hyclate (DOXY). The release characteristics of DOXY from DOXY-loaded PCL/PHBV fibrous substrates were carried out by the total immersion method in a phosphate buffer solution In vitro antibacterial activity of these fibrous substrates was also tested against Gramnegative Pseudomonas aeruginosa and Tram-positive Staphylococcus aureus.