Electrospun Nanofibrils Surface-Decorated with Photo-Cross-Linked Hyaluronic Acid for Cell-Directed Assembly

Hyaluronic acid (HA) was chemically immobilized on the surface of electrospun nanofibrils to form a cell/NF complex. Poly(caprolactone) (PCL) was electrospun into nanofibrous mats that were subsequently aminolyzed into nanofibrils. The aminolyzed nanofibrils were surface-decorated with methacrylated HA via Michael type addtion and by photo-cross-linking. Fourier transform infrared spectroscopy revealed the presence of HA on the surface of the nanofibrils. The thermogravimetric and colorimetric analyses indicate that the degree of HA immobilization could be varied by varying the photo-cross-linking duration. Thus, on increasing the photo-cross-linking duration, the swelling ratios increased gradually, and the surface charge of the decorated nanofibrils decreased. NIH3T3 cells and surface-decorated nanofibrils spontaneously assembled into the cell/NF complex. A higher degree of surface-immobilized HA enhanced cell viability and proliferation compared to nanofibrils without surface-immobilized HA. Thus, we envision that HA-immobilized nanofibrils can be employed as a tissue-engineering matrix to control cell proliferation and differentiation.