Effect of Nintedanib Nanothermoreversible Hydrogel on Neovascularization in an Ocular Alkali Burn Rat Model

Abstract

Purpose

To compare the therapeutic effects of different forms of nintedanib ophthalmic preparations on neovascularization corneal alkali burns in rats.

Methods

Forty rat models of left eye corneal alkali burns were constructed, and the five groups (N = 8) were treated with normal saline, dexamethasone ointment (dexamethasone), 0.2% nintedanib aqueous solution and nintedanib nano thermoreversible hydrogel (NNTH). A slit lamp microscope was used to observe the area of neovascularization. The levels of the inflammatory factors were detected by ELISA. HE staining was performed on the rat corneas. Vascular endothelial growth factor (VEGFA) was detected by immunohistochemistry, and the expression of corneal VEGFA and CD31 was detected by western blotting. An MTT assay was performed to detect the cytotoxicity of nintedanib on human corneal epithelial cells (HCECs) and human umbilical vein vascular endothelial cells (HUVECs). Cell migration was detected by a cell scratch assay, and the proportion of apoptotic cells was detected by Annexin/PI double staining. Immunofluorescence and western blotting were performed to detect the protein expression of VEGFA and CD31.

Results

NNTH had a stronger inhibitory effect on corneal neovascularization (CNV) in alkali-burned rats while reducing the level of inflammatory factors. NNTH had a longer drug duration of release than nanoformulations in vitro. Nintedanib at low concentrations (<8 μM) had no significant cytotoxicity to HCECs but significantly induced apoptosis and inhibited the expression of VEGFA and CD31 and the migration of HUVECs.

Conclusions

Nanomorphic thermoreversible hydrogel is superior among the nintedanib ophthalmic preparations, showing better inhibition of CNV in alkali-burned eyeballs and it blocked the migration and proangiogenic ability of HUVECs.

Keywords:

• Nintedanib
• thermoreversible hydrogel
• alkali burn
• corneal neovascularization (CNV)
• ophthalmic preparations

Ethics approval

Ethical approval was obtained from Ningbo University Animal Testing Center (number. SYXK 2013—0191).

Author contributions

X.L. and S.W. designed the study and developed the methodology. X.L., Y.G. and S.W. analysed and interpreted the data and wrote the original draft. Y.G., L.Y. and S.W. performed the experiments and collected the data.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets used in the current study are available from the corresponding author upon reasonable request.

Additional information

Funding

Funding was supported by General class A of the Zhejiang Medical and Health Science and Technology Plan Project in 2020 [2020ky288]; Yinzhou District Agriculture and Social Development Field Science and Technology Project [2021AS0058 and 2020AS0080]; Zhejiang Provincial Science and Technology Program of Traditional Chinese Medicine [2021ZB268]; and Health Science and Technology Program of Zhejiang Province [2021PY073].