Cytotoxicity Study of UV-Laser-Irradiated PLLA Surfaces Subjected to Bio-Ceramisation: A New Way towards Implant Surface Modification

Abstract

In this research we subjected samples of poly(L-lactide) (PLLA) extruded film to ultraviolet (193 nm ArF excimer laser) radiation below the ablation threshold. The modified film was immersed in Simulated Body Fluid (SBF) at 37 °C for 1 day or 7 days to obtain a layer of apatite ceramic (CaP) coating on the modified PLLA surface. The samples were characterized by means of optical profilometry, which indicated an increase in average roughness (Ra) from 25 nm for the unmodified PLLA to over 580 nm for irradiated PLLA incubated in SBF for 1 day. At the same time, the water contact angle decreased from 78° for neat PLLA to 35° for irradiated PLLA incubated in SBF, which suggests its higher hydrophilicity. The obtained materials were investigated by means of cell response fibroblasts (3T3) and macrophage-like cells (RAW 264.7). Properties of the obtained composites were compared to the unmodified PLLA film as well as to the UV-laser irradiated PLLA. The activation of the PLLA surface by laser irradiation led to a distinct increase in cytotoxicity, while the treatment with SBF and the deposition of apatite ceramic had only a limited preventive effect on this harmful impact and depended on the cell type. Fibroblasts were found to have good tolerance for the irradiated and ceramic-covered PLLA, but macrophages seem to interact with the substrate leading to the release of cytotoxic products.

Integrating Fly Ash-Controlled Surface Morphology and Candle Grease Coating: Access to Highly Hydrophobic Poly (L-lactic Acid) Composite for Anti-Icing Application

“…In this study, the rough surface of PLLA composites with crystalline microspheres and FA@KH570 particles was successfully assembled via a straightforward solvent-volatilization-induced phase separation method. Afterward, the PLLA/FA@KH570 composites were coated with candle grease by a simple melt-coating method to reduce the surface energy, finally exhibiting surface super-hydrophobicity [ 56 ].…”

Recent Advances in Functional Polymer Materials for Energy, Water, and Biomedical Applications: A Review

“…This surface activation could be performed chemically by grafting different active functions and branches, or physically, via different techniques, such as plasma treatment, laser treatment, UV irradiation, ozonolysis, electron beams, etc. [18][19][20][21][22][23][24]. Functionalization of polymeric surfaces is generally provided chemically either via covalent bonds and low energy interactions [25][26][27], or by non-covalent physical attraction, such as the adsorption of pollutants [28,29], antibacterial biomaterials [30][31][32], and drug delivery systems [33][34][35].…”