Haloarchaeal poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate)] composite films reinforced with graphene nanoplatelets as a biomaterial for skin tissue engineering

Abstract

Halophilic archaea are an untapped source for a wide range of applications. This study explores the potential of a copolymer poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate) (PHBV), naturally synthesized by the halophilic archaeon, Halogeometricum borinquense E3, as a potential candidate for a tissue engineering biomaterial. Composites and blends from natural PHBV were fabricated with poly(L-lactic acid) (PLLA), poly(ε-caprolactone) (PCL) and graphene nanoplatelets (GNP) to enhance the properties of the material. This significantly improved the tensile strength of the blend to 4.729 MPa (359%). The reinforcement with 0.3% w/v of GNP further increased the tensile strength to 13.268 MPa (981%). Characterization of the films was done using ATR-FTIR, XRD, TGA, and SEM. The haloarchaeal PHBV exhibited the highest porosity ergo the highest swelling percentage while the PHBV/GNP showed the least. All the films showed good biocompatibility compared to tissue culture plastic (TCP). The viability of HaCaT cells and L929 fibroblast cells was maximum on the PHBV/PLLA/PCL blend albeit no significant change in the cell viability was observed in the graphene-reinforced nanocomposite. The films were also highly hemocompatible (<5% hemolysis).