A long-term retaining molecular coating for corneal regeneration

Abstract

Corneal injuries will cause corneal surface diseases that may lead to blindness in millions of people worldwide. There is a tremendous need for biomaterials that can promote corneal regeneration with practical feasibility. Here we demonstrate a strategy of a protein coating for corneal injury regeneration. We synthesize an o-nitrosobenzaldehyde group (NB)-modified gelatin (GelNB), which could adhere directly to the corneal surface with covalent bonding to form a thin molecular coating. The molecular coating could avoid rapid clearance and provide a favorable environment for cell migration, thereby effectively accelerating corneal repair and regeneration. The histological structure of the regenerated cornea is more similar to the native cornea. This molecular coating can be used conveniently as an eye drop solution, which makes it a promising strategy for corneal regeneration.

GelNB molecular coating as a biophysical barrier to isolate intestinal irritating metabolites and regulate intestinal microbial homeostasis in the treatment of inflammatory bowel disease

“…However, they also have many limitations when applied to IBD, such as low bioavailability, non-specific tissue distribution, rapid elimination, and poor colon retention [ [24] , [25] , [26] ]. Our “GelNB molecular coating” was confirmed to have outstanding adhesion performance, long-term retention performance, and convenient usage [ 21 ]. GelNB was dissolved in water and directly injected into the intestine after being activated by UV light.…”

“…In addition, the healing of defective epithelium can only be repaired more rapidly when a given biomaterial recruits surrounding epithelial cells [ 21 ]. Therefore, we tested whether GelNB could promote this migration using a cell scratch experiment.…”

“…GelNB was dialyzed and lyophilized according to previously described methods [ 21 ]. GelNB was synthesized by adding Gelatin and carboxyl groups of NBCOOH into the reaction under the catalysis of 1-(3-Dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride (EDC) (Aladdin, China) and N -hydroxy succinimide (NHS) (Aladdin) in dimethyl sulfoxide (DMSO, Sigma-Aldrich, USA).…”

“…GelNB was synthesized by adding Gelatin and carboxyl groups of NBCOOH into the reaction under the catalysis of 1-(3-Dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride (EDC) (Aladdin, China) and N -hydroxy succinimide (NHS) (Aladdin) in dimethyl sulfoxide (DMSO, Sigma-Aldrich, USA). The mixture was carefully dripped into Gelatin solution (Sigma-Aldrich) and stirred at 45 °C for 4 h. Subsequently, the mixture was slowly dripped into a 10% w/v homogeneous Gelatin solution (Sigma-Aldrich) maintained at 37 °C and stirred at 45 °C for 4 h. After dialyzing the GelNB solution in distilled water for 72 h, the GelNB fraction was collected, lyophilized, and stored at 4 °C for further use [ 21 ].…”

“…Here, we propose a strategy for isolating external stimuli and regulating intestinal microecology through “molecular coating.” In a previous study, we prepared a molecular coating that could recruit cells and promote corneal repair [ 21 ]. This molecular coating is composed of o-nitrobenzaldehyde (NB)-modified Gelatin (GelNB), which can strongly bond with –NH 2 on the tissue surface via photogenerated aldehyde groups after ultraviolet light (UV) activation [ 22 ].…”