Design of femtosecond microstructured poly lactic acid temporal scaffolds coated with hydroxyapatite by pulse laser deposition method for bone tissue regeneration.

The aim of the present study is to create porous poly lactic acid (PLA)-based temporal cellular scaffolds with specifically designed topographical orientation by means of femtosecond laser (fs)-induced microstructuring, additionally functionalized by a nanometric layer of hydroxyapatite (HA) by the pulse laser deposition (PLD) method. For this purpose, surface micromodification of PLA samples by means of a CPA Ti:sapphire fs laser system (τ = 150 fs, λ = 800 nm, ѵ = 0.5 kHz), operating at fluence F = 0.8 J/cm2 and scanning velocity V = 3.8 mm/s, was combined with PLD of thin layer of HA on the patterned PLA matrices for cellular scaffold surface additional nanofunctionalization. Each laser structured PLA scaffold was analyzed with respect to its control and laser processed surface, covered with HA. The multilevel structured scaffolds were investigated by SEM, EDX, 3D profilometer, AFM, micro-Raman and WCA analyses. Cytocompatibility studies with MG63 osteoblastic cells were also performed. Moreover, the cellular behavior was compared with the one observed on HA spin-coated fs microstructured PLA temporary scaffolds, in order to compare the two methods of functionalization. A disordered spreading on smooth surfaces to a tendency of cell orientation and elongation along the laser created grooves was monitored, along with increased alkaline phosphatase activity, which could essentially improve their subsequent practical application in engineering of personalized bone tissue. [ABSTRACT FROM AUTHOR]