Enhanced cell affinity of PHBHHx composite scaffold with polylactide-graft-hydroxyapatite as compatibilizer

- Well-dispersed g-HA/PHB scaffolds were fabricated via the surface-grafting strategy.
- The superficial-modified HA nanoparticles acted as compatibilizer bridging the PHB matrix and inorganic particles.
- The physicochemical properties and cell response of g-HA/PHB scaffolds were better.
- Some of the osteogenic marker genes were up-regulated, thus making for the osteogenic differentiation.

Poor interfacial bonding and liability to aggregation were the major obstacles for designing of composite scaffolds. Herein, hydroxyapatite (HA) surface-grafted with poly (l-lactide) via ring-opening polymerization was prepared and introduced into PHBHHx-based complex scaffold serving as oligomer compatibilizer. The physicochemical properties, including superficial roughness and wettability, mechanical strength, as well as in vitro bioactivity were systematically investigated. Improved cellular response was acquired owing to the favourable uniformity and interfacial compatibility, as well as the decreased contact angle and elevated roughness, through surface-modification strategy. Moreover, some of the osteogenic marker genes (COL I, Runx2, OCN and OPN) were up-regulated, thus made for the osteogenic differentiation. Our study extrapolated that the PHBHHx-based composite scaffold combined with surface-graft HA compatibilizer might be a potential candidate for bone repairing.

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