Core–shell structured electrospun biomimetic composite nanofibers of calcium lactate/nylon-6 for tissue engineering

[Display omitted] ► Core–shell nanofibers of nylon-6/lactic acid are fabricated by single-spinneret. ► Surface lactic acid is easily converted into calcium lactate by neutralization. ► Calcium lactate coated nylon-6 fiber offers nucleation site for HAp deposition. ► Calcium lactate coated nylon-6 composite fibers has good cell compatibility. In this work, core-shell structured nylon-6/lactic acid (LA) nanofibers have been produced via single-spinneret electrospinning from the simple blending of LA and nylon-6 solution. The low evaporation rate and plasticizer property of LA was found to be responsible for the formation of point-bonded morphology whereas solvent degradation of nylon-6 with complex phase separation mechanism could give spider-wave-like architecture of the mat and core–shell structure of the composite fibers. The core–shell nanostructure and existence of LA on the shell layer of the fiber were confirmed by TEM and XPS analysis. These fibers were further treated with calcium base to convert surface LA into calcium lactate (CL) which could increase the biocompatibility of composite mat. The SBF incubation test not only confirmed the nucleation capacity of CL to accelerate the deposition of calcium compound on the surface of nanofibers but also facileated the formation of hollow calcium phosphate particles at biomimetic conditions. The adhesion, viability and proliferation properties of osteoblast cells on the composite nanofibers were analyzed by in vitro cell compatibility test. This study demonstrated the non-cytotoxic behavior and good proliferation capacity of calcium lactate/nylon-6 (CL/nylon-6) composite mat. Therefore, the novel nanofibrous composite mat may become a potential candidate for bone tissue engineering.