Purpose: The aim of this study was to synthesize bevacizumab-loaded nanoparticles and evaluate their effects on the treatment of posterior segment diseases via subtenon injections. Methods: Bevacizumab-loaded chitosan nanoparticles (BLCNs) were synthesized by the ionic gelation method, and their physicochemical characteristics and in vitro release profile were studied. The BLCNs were characterized using atomic force microscopy (AFM), FTIR spectroscopy, dynamic light scattering, and scanning electron microscopy. The BLCNs were delivered into rabbits' eyes via posterior subtenon injections. An immunohistochemical evaluation of the ocular tissues was performed, and the vitreous humor and serum bevacizumab levels were measured by ELISA. Results: Bevacizumab-loaded chitosan nanoparticles with a diameter of 80 to 380 nm were prepared and characterized. In vitro studies showed that after the first 5 days of the experiment, a significant increase in the drug release maintained the desired drug dosage for 3 weeks. Immunohistochemical in vivo studies revealed that there were BLCNs penetrating through the sclera. Furthermore, the intravitreal bevacizumab concentration reached a maximum concentration of 18 μg/ml, and it decreased to 6 μg/ml after only a week. Conclusion: The results revealed that subtenon injection of BLCNs is a promising alternative to intravitreal injections. In addition to the ELISA studies, immunohistochemical experiments confirmed that BLCNs enable transscleral bevacizumab penetration, and BLCN usage may provide the required bevacizumab levels for the treatment of posterior segment diseases.

中文翻译：

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贝伐单抗负载的壳聚糖纳米颗粒的跨巩膜递送。

目的：本研究的目的是合成贝伐单抗纳米颗粒，并通过亚腱注射评估其对后段疾病治疗的效果。方法：采用离子凝胶法合成贝伐单抗壳聚糖纳米粒（BLCNs），研究其理化特性和体外释放特性。使用原子力显微镜（AFM），FTIR光谱，动态光散射和扫描电子显微镜对BLCN进行表征。BLCNs通过后亚腱注射被递送到兔子的眼睛中。进行了眼组织的免疫组织化学评估，并通过ELISA测量了玻璃体液和血清贝伐单抗水平。结果：制备并表征了负载贝伐单抗的直径为80至380 nm的壳聚糖纳米颗粒。体外研究表明，在实验的前5天后，药物释放的显着增加将所需的药物剂量维持了3周。体内免疫组织化学研究表明，有BLCN穿透巩膜。此外，玻璃体内贝伐单抗浓度达到18的最大浓度μ微克/毫升，并将其降低到6 μ微克/毫升之后仅一周。结论：结果表明，BLCNs的亚腱注射是玻璃体内注射的有希望的替代方法。除ELISA研究外，免疫组织化学实验还证实BLCN可以使巩膜贝伐单抗穿透，BLCN的使用可能为治疗后段疾病提供所需的贝伐单抗水平。