Institute of Organic Synthesis and Photoreactivity - Italian National Research Council, Via P. Gobetti 101, 40129 Bologna, Italy.
MIST E-R Laboratory, via P. Gobetti 101, 40129 Bologna, Italy.
Biomacromolecules. 2016 Sep 12;17(9):2882-90. doi: 10.1021/acs.biomac.6b00697. Epub 2016 Aug 9.
Photoactivatable keratin sponges were prepared from protein aqueous solutions by the freeze-drying method, followed by photofunctionalization with two different photosensitizers (PS): Azure A (AzA) and 5,10,15,20-tetrakis [4-(2-N,N,N-trimethylethylthio)-2,3,5,6-tetrafluorophenyl]porphyrin tetraiodide salt (TTFAP). The prepared sponges have a porosity between 49% and 80% and a mean pore size in the 37-80 μm range. As compared to AzA, TTFAP interacts more strongly with the sponges as demonstrated by a lower PS release (6% vs 20%), a decreased swelling ratio (1.6 vs 7.4), and a slower biodegradation rate. Nevertheless, AzA-loaded sponges showed the highest photoactivity, as also demonstrated by their higher antibactericidal activity toward both Gram-positive and Gram-negative bacteria. The obtained results suggest that the antimicrobial photodynamic effect can be finely triggered through a proper selection of the amount and type of photosensitizer, as well as through the irradiation time. Finally, all the prepared sponges support human fibroblast cells growth, while no significant cell viability impairment is observed upon light irradiation.
光活化角蛋白海绵由蛋白质水溶液通过冷冻干燥法制备，然后用光功能化两种不同的光敏剂（PS）：Azure A（AzA）和 5,10,15,20-四[4-（2-N,N,N-三甲基乙基硫代）-2,3,5,6-四氟苯基]卟啉四碘化物盐（TTFAP）。所制备的海绵具有 49％至 80％的孔隙率和 37-80μm 范围内的平均孔径。与 AzA 相比，TTFAP 与海绵的相互作用更强，这表现为 PS 释放率更低（6％对 20％）、溶胀比降低（1.6 对 7.4）和生物降解速率更慢。然而，载有 AzA 的海绵表现出最高的光活性，这也证明了它们对革兰氏阳性和革兰氏阴性细菌都具有更高的抗菌光动力活性。所得结果表明，通过适当选择光敏剂的量和类型以及辐照时间，可以精细触发抗菌光动力效应。最后，所有制备的海绵都支持人成纤维细胞的生长，而在光照下没有观察到明显的细胞活力损伤。
