In vitro and in vivo biological characterization of poly(lactic acid) fiber scaffolds synthesized by air jet spinning.

Poly(lactic acid) (PLA) is one of the most promising renewable and biodegradable polymers for mimic extracellular matrix for tissue engineering applications. In this work, PLA spun membrane scaffold were successfully prepared by air jet spinning technology. Morphology, mechanical properties, in vitro biocompatibility, and in vitro and in vivo degradation of PLA fibrous scaffold were characterized by X-ray diffraction, Fourier Transform Infrared, and scanning electron microscope (SEM). Morphological results assessed by SEM analyses indicated that PLA scaffolds possessed an average fiber diameter of approximately 0.558 ± 0.141 µm for 7% w/v of PLA and approximately 0.647 ± 0.137 µm for 10% w/v. Interestingly, our results showed that the nanofiber size of PLA scaffold allow structural stability after 100 days of in vitro degradation in Ringer solution where the average fiber diameter were of approximately 0.633 ± 0.147 µm for 7% w/v and approximately 0.645 ± 0.140 µm for 10% w/v of PLA. Mechanical properties of PLA fibers scaffold after in vitro degradation showed decrease in terms of flexibility elongation, and less energy was needed to achieve maximal elastic deformation. The fiber size exerts an influence on the biological response of human Bone Marrow Mesenchymal Stromal Cells as confirmed by MTT assay after 9 days of cell culture and the in vivo degradation assay of 7% w/v and 10% w/v of PLA scaffold, did not demonstrate evidence of toxicity with a mild inflammatory respond. In conclusion, airbrushing technology promises to be a viable and attractive alternative technique for producing a biocompatible PLA nanofiber scaffold that could be considered for tissue engineering regeneration.