Yao Yili, Wang Lei, Ding Jiangtao, Pan Xinyang, Yang Linxing, Guo Changrong, Wang Yuanhao, Gruber Reinhard, Nan Kaihui, Li Lingli
National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.
National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang 325027, China; Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang 325000, China; The Affiliated Xiangshan Hospital of Wenzhou Medical University, Ningbo, Zhejiang 315700, China.
J Control Release. 2025 Apr 10;380:71-84. doi: 10.1016/j.jconrel.2025.01.080. Epub 2025 Feb 4.
Neurotrophic keratopathy is a degenerative disease caused by corneal nerve damage, leading to corneal ulceration. Recombinant human nerve growth factor (rhNGF) was approved for neurotrophic keratitis therapy; however, the excipients of the eye drops are not optimized for its controlled release. To this aim, we introduce the hypotonic hydrogel PF127 as an excipient for rhNGF in eye drops. We confirmed the formation of a hydrogel using a vial-inversion test and based on rheological properties. The hydrogel exerts shear-thinning behavior upon sweep test with a favorable transmittance and a natural refractive index. Moreover, the hydrogel exhibited fast and sustained rhNGF release kinetic, along with constant dissolution and the formation of a network-like structure. The release of rhNGF was confirmed by the proliferation of PC12 cells and its protective effect on damaged axons of dorsal root ganglia cells. The hydrogel performed accordingly in the in-situ ocular gelation and ocular surface retention test. We further confirmed that labeled proteins were released from the hydrogel to the cornea. Preclinical testing in mice showed that rhNGF hydrogels supported the recovery from corneal epithelial defects: they reduced the defect size and increased corneal nerve density. Schirmer's test revealed improved corneal nerve function based on tear secretion. The hydrogel resists clearance from blinking and enhances the intraocular absorption of rhNGF. The ocular surface, retinal thickness, and the ciliary body and retina remained unchanged. Together, these findings suggest that the hypotonic PF127 hydrogel is a suitable rhNGF delivery system to prepare eye drops for potential use in neurotrophic keratopathy.
神经营养性角膜病变是一种由角膜神经损伤引起的退行性疾病，可导致角膜溃疡。重组人神经生长因子（rhNGF）已被批准用于神经营养性角膜炎的治疗；然而，滴眼液的辅料并未针对其控释进行优化。为此，我们引入了低渗水凝胶PF127作为rhNGF滴眼液的辅料。我们通过小瓶倒置试验并基于流变学特性证实了水凝胶的形成。该水凝胶在扫描试验中表现出剪切变稀行为，具有良好的透光率和自然折射率。此外，该水凝胶呈现出快速且持续的rhNGF释放动力学，同时具有恒定的溶解和网络状结构的形成。通过PC12细胞的增殖及其对背根神经节细胞受损轴突的保护作用证实了rhNGF的释放。该水凝胶在原位眼凝胶化和眼表保留试验中表现良好。我们进一步证实标记蛋白从水凝胶释放到角膜。在小鼠中的临床前测试表明，rhNGF水凝胶有助于角膜上皮缺损的恢复：它们减小了缺损大小并增加了角膜神经密度。泪液分泌试验显示基于泪液分泌的角膜神经功能得到改善。该水凝胶可抵抗眨眼清除并增强rhNGF的眼内吸收。眼表、视网膜厚度以及睫状体和视网膜均保持不变。总之，这些发现表明低渗PF127水凝胶是一种合适的rhNGF递送系统，可用于制备滴眼液，有望用于神经营养性角膜病变。
