Electrospinning biomedical nanocomposite fibers of hydroxyapatite/poly(lactic acid) for bone regeneration

Development of fibrous matrices of bioceramic-biopolymer nanocomposite offers great potential in the field of bone regeneration and tissue engineering. However, in order to produce electrospun fibers with homogeneous structure, it is essential for the ceramic powder to be fine and to remain stable in suspension. Herein, we developed a novel method whereby the bioceramic hydroxyapatite (HA) was kept in suspension in biopolymer poly(lactic acid) (PLA). The strategy was to introduce a surfactant hydroxysteric acid (HSA) between the hydrophilic HA powder and the hydrophobic chloroform-dissolved PLA. The HA nanopowder was dispersed effectively in HSA and mixed homogeneously with PLA. Continuous and uniform fibers were generated successfully with diameters of approximately 1-2 microm, and featured a well-developed nanocomposite structure of HA nanopowder-dispersed PLA. Initial cellular assays showed excellent cell attachment and proliferation and also enhanced expression of alkaline phosphatase at 7 days of culturing. The HA-PLA nanocomposite fibers may be potentially useful in tissue engineering applications, particularly as three-dimensional substrates for bone growth.