Toughening of electrospun poly(L-lactic acid) nanofiber scaffolds with unidirectionally aligned halloysite nanotubes

The mechanical properties of the tissue engineering scaffold are important as they are tightly related the regeneration of structural tissue. The application of poly(l-lactic acid) (PLLA) nanofiber scaffolds in tissue engineering has been hindered by their insufficient mechanical properties. In the study, halloysite nanotubes (HNTs) were used to reinforce the mechanical properties of PLLA-based nanofibers. 4 wt% HNT/PLLA nanofiber membranes possess the best mechanical performance, which represents 61 % increase in tensile strength, 100 % improvement of Young's modulus, 49 % augment of elongation to break, as well as 181 % elevation in energy to break compared with neat PLLA samples. The satisfactory enhancement effect of HNTs can be attributed to the effective dispersion and incorporation of HNTs in PLLA matrix, which have been confirmed by the analysis of SEM, TEM, and FTIR. The addition of HNTs also improves the degree of crystallization and thermal stability of PLLA-based nanofibers. HNT-incorporated PLLA nanofiber membranes possess higher protein adsorption from fetal bovine serum than the neat PLLA specimen. Therefore, the introduction of HNTs can effectively enhance the mechanical properties of PLLA nanofiber scaffolds. HNT/PLLA nanofiber scaffolds possess potential application in skin tissue engineering.