Lactic acid assisted fabrication of bioactive three-dimensional PLLA/β-TCP fibrous scaffold for biomedical application

Abstract

Low-density, high porous bioactive fibrous scaffolds have attracted significant attention for tissue engineering. However, fabrication of biomimetic fibrous scaffolds having three-dimensional architecture along with bioactive materials still remains a challenging task for biomaterial scientists. Herein, for the first time, we developed a novel strategy to fabricate highly porous ß-tricalcium phosphate (ß-TCP) incorporated Poly (l-lactide) (PLLA) fibrous scaffold for bone tissue engineering. Blending of PLLA with its monomer, lactic acid (LA) produced the fluffy type highly porous nanofibrous mesh. The mass composition of the constituents of the blend solution was varied to control the morphology and packing of the nanofibers in the scaffold. The results showed that LA played the vital role in the generation of the 3D fluffy type fibrous mesh. ß-TCP particles were incorporated in the blend solution prior to the electrospinning solution, to fabricate ß-TCP incorporated PLLA fibrous scaffold. Later, LA was leached out by washing with distilled water, to avoid its adverse effect on biocompatibility. Digital and SEM images revealed the formation of spongy, low-density fibrous mesh. TEM images, IR, and TGA analysis confirmed the presence of ß-TCP nanoparticles in the nanofibers after leaching of LA. Incorporation of the ß-TCP enhanced the water uptake ability, in vitro bio-mineralization, and bioactivity of the fibrous scaffold. Confocal microscopy images showed that the pre-osteoblast cells seeded on the fluffy type fibrous mesh infiltrated throughout the depth of the scaffold, compared to no penetrating growth for the 2D scaffold. In vitro biocompatibility evaluated by CCK assay showed significantly higher growth for cells on the fluffy type scaffold, compared to the 2D scaffold. We demonstrated scaffolds suitability for biocompatibility and osteogenic differentiation of hMSCs as well. We believe that the fabrication of bioactive particle incorporated highly porous 3D fibrous scaffold will open a new avenue for tissue engineering applications.