Ali Sarah M, Gomaa Elshimaa H, Badr Entsar E, Azooz M A, Farag Mohammad M
Department of Chemistry, Faculty of Science, Al-Azhar University (Girls' Branch), Nasr City, Egypt.
Glass Research Department, National Research Centre, 33 El-Behooth Str., Dokki, 12622 Giza, Egypt.
J Photochem Photobiol B. 2025 Jul;268:113179. doi: 10.1016/j.jphotobiol.2025.113179. Epub 2025 May 6.
Development of suitable tissue engineering scaffolds to be loaded with photosensitizer drugs applied in photodynamic therapy is considered a critical issue. This study we introduced new delivery system based on cerium- and silver-doped nanobioactive glass (nBG)/chitosan/collagen composite scaffolds as a carrier for a photosensitizer, methylene blue (MB), in photodynamic therapy, capitalizing on the unique photocatalytic and antibacterial properties of the doped nBG. Cerium and silver offer additional benefits in terms of antimicrobial, anticancer, and wound healing properties. MB is an effective and inexpensive therapeutic photosensitizer compound that exhibits antimicrobial activity through light activation and has shown great potential for selectively treating infected cells. The prepared scaffolds were characterized by FTIR, TGA, and SEM/EDX. The bioactivity and biodegradation were conducted in SBF. The cell viability was carried out against the WI-38 cell line. Finally, the antibacterial efficiency of scaffolds loaded with MB was evaluated before and after laser irradiation against Staphylococcus aureus, Bacillus subtilis (Gram-Positive), and Pseudomonas aerginousea, klebsiella pneumoniae (Gram-negative). Inhibition of bacteria by reactive oxygen species (ROS) was also measured. Furthermore the primarily MB release profile and kinetic were studied. The results showed that nBG particles increased the thermal stability of the scaffolds, and enhanced the formation of an apatite bone-like layer on the scaffold surfaces. Furthermore, scaffold degradation was tailored by changing the amount of nBG. Moreover, the water uptake of the scaffold containing undoped nBG particles (G010 and G020 samples) showed higher water uptake percentages (682 % and 762 %, respectively) than doped nBG (for 155 % and 322 % for GA10 and GA20, respectively). All scaffolds demonstrated good cell viability at concentrations up to 62.5 μg/ml. However, at higher concentrations, scaffolds incorporating high percentages of nBG were more viable than those containing low amounts of nBG, regardless of the glass composition. The antibacterial tests presented that the MB enhanced scaffold antibacterial efficiency by improving the oxidative stress on bacterial cells, which significantly increased after irradiation. Finally, the release mechanism of MB was diffusion mechanism for scaffolds contained nBG particles, while it did not follow this mechanism for blank polymer scaffolds. In conclusion, these results suggest that the developed multifunctional scaffolds hold significant promise for effective photodynamic antimicrobial chemotherapy in the treatment of microbial infections.
开发适用于光动力疗法中负载光敏剂药物的组织工程支架被认为是一个关键问题。在本研究中，我们引入了一种基于铈和银掺杂的纳米生物活性玻璃（nBG）/壳聚糖/胶原蛋白复合支架的新型递送系统，作为光动力疗法中光敏剂亚甲蓝（MB）的载体，利用掺杂nBG独特的光催化和抗菌性能。铈和银在抗菌、抗癌和伤口愈合性能方面具有额外的益处。MB是一种有效且廉价的治疗性光敏剂化合物，通过光激活表现出抗菌活性，并已显示出在选择性治疗感染细胞方面的巨大潜力。通过傅里叶变换红外光谱（FTIR）、热重分析（TGA）以及扫描电子显微镜/能谱仪（SEM/EDX）对制备的支架进行了表征。在模拟体液（SBF）中进行了生物活性和生物降解测试。针对WI-38细胞系进行了细胞活力测试。最后，评估了负载MB的支架在激光照射前后对金黄色葡萄球菌、枯草芽孢杆菌（革兰氏阳性菌）以及铜绿假单胞菌、肺炎克雷伯菌（革兰氏阴性菌）的抗菌效率。还测量了活性氧（ROS）对细菌的抑制作用。此外，对MB的初始释放曲线和动力学进行了研究。结果表明，nBG颗粒提高了支架的热稳定性，并增强了支架表面类骨磷灰石层的形成。此外，通过改变nBG的含量来调整支架的降解。而且，含有未掺杂nBG颗粒的支架（G010和G020样品）的吸水率分别为682%和762%，高于掺杂nBG的支架（GA10和GA20分别为155%和322%）。所有支架在浓度高达62.5μg/ml时均表现出良好的细胞活力。然而，在较高浓度下，无论玻璃成分如何，掺入高百分比nBG的支架比含有低量nBG的支架更具活力。抗菌测试表明，MB通过改善细菌细胞上的氧化应激来提高支架的抗菌效率，照射后这种效率显著提高。最后，对于含有nBG颗粒的支架，MB的释放机制为扩散机制，而空白聚合物支架则不遵循此机制。总之，这些结果表明，所开发的多功能支架在治疗微生物感染的有效光动力抗菌化疗方面具有巨大潜力。
