In Situ Biological Transmutation of Catalytic Lactic Acid Waste into Calcium Lactate in a Readily Processable Three-Dimensional Fibrillar Structure for Bone Tissue Engineering

A bioinspired three-dimensional (3D) fibrous structure possesses biomimicry, valuable functionality, and performance to scaffolding in tissue engineering. In particular, an electrospun fibrous mesh has been studied as a scaffold material in various tissue regeneration applications. We produced a low-density 3D polycaprolactone/lactic acid (LA) fibrous mesh (3D-PCLS) via the novel lactic-assisted 3D electrospinning technique exploiting the catalytic properties of LA as we reported previously. In the study, we demonstrated a strategy of recycling the LA component to synthesize the osteoinductive biomolecules in situ, calcium lactate (CaL), thereby forming a 3D bioactive PCL/CaL fibrous scaffold (3D-SCaL) for bone tissue engineering. The fiber morphology of 3D-PCLS and its packing degree could have been tailored by modifying the spinning solution and the collector design. 3D-SCaL demonstrated successful conversion of CaL from LA and exhibited the significantly enhanced biomineralization capacity, cell infiltration and proliferation rate, and osteoblastic differentiation in vitro with two different cell lines, MC3T3-e1 and bone marrow stem cells. In conclusion, 3D-SCaL proves to be a highly practical and accessible strategy using a variety of polymers to produce 3D fibers as a potential candidate for future regenerative medicine and tissue engineering applications.