Department of Polymer Engineering and Technology, Faculty of Chemistry, Wrocław University of Science and Technology (WUST), Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland.
Laser and Fiber Electronics Group, Faculty of Electrical Engineering, Wrocław University of Science and Technology, 50-370 Wrocław, Poland.
Int J Mol Sci. 2021 Aug 5;22(16):8436. doi: 10.3390/ijms22168436.
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.
在这项研究中，我们将聚（L-丙交酯）（PLLA）挤出膜样品置于低于消融阈值的紫外（193nm ArF 准分子激光）辐射下。将改性后的薄膜在 37°C 的模拟体液（SBF）中浸泡 1 天或 7 天，以在改性 PLLA 表面获得一层磷灰石陶瓷（CaP）涂层。通过光学轮廓仪对样品进行了表征，结果表明，与未经改性的 PLLA 的平均粗糙度（Ra）从 25nm 增加到在 SBF 中孵育 1 天的辐照 PLLA 的超过 580nm。同时，水接触角从纯 PLLA 的 78°降低到在 SBF 中孵育的辐照 PLLA 的 35°，表明其亲水性更高。通过纤维母细胞（3T3）和巨噬细胞样细胞（RAW 264.7）对获得的材料进行了研究。将获得的复合材料的性能与未改性的 PLLA 薄膜以及经紫外激光辐照的 PLLA 进行了比较。激光辐照对 PLLA 表面的活化导致细胞毒性明显增加，而 SBF 处理和磷灰石陶瓷的沉积对这种有害影响只有有限的预防作用，并且取决于细胞类型。发现纤维母细胞对辐照和陶瓷覆盖的 PLLA 具有良好的耐受性，但巨噬细胞似乎与底物相互作用，导致细胞毒性产物的释放。
