Synthesis of Strong Adhesive Hydrogel, Gelatin O-Nitrosobenzaldehyde

Summary

The protocol presented here shows the synthesis of a strong adhesive hydrogel gelatin o-nitrosobenzaldehyde (gelatin-NB). Gelatin-NB has rapid and efficient tissue adhesion ability, which can form a strong physical barrier to protect wound surfaces, so it is expected to be applied to the field of injury repair biotechnology.

Abstract

Adhesive materials have become popular biomaterials in the field of biomedical and tissue engineering. In our previous work, we presented a new material - gelatin o-nitrosobenzaldehyde (gelatin-NB) - which is mainly used for tissue regeneration and has been validated in animal models of corneal injury and inflammatory bowel disease. This is a novel hydrogel formed by modifying biological gelatin with o-nitrosobenzaldehyde (NB). Gelatin-NB was synthesized by activating the carboxyl group of NB-COOH and reacting with gelatin through 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). The obtained compound was purified to generate the final product, which can be stably stored for at least 18 months. NB has a strong adhesion to -NH₂ on the tissue, which can form many C = N bonds, thus increasing the adhesion of gelatin-NB to the tissue interface. The preparation process comprises steps for the synthesis of the NB-COOH group, modification of the group, synthesis of gelatin-NB, and purification of the compound. The goal is to describe the specific synthesis process of gelatin-NB in detail and to demonstrate the application of gelatin-NB to damage repair. Moreover, the protocol is presented to further strengthen and expand the nature of the material produced by the scientific community for more applicable scenarios.

Introduction

Hydrogel is a type of three-dimensional polymer formed by water swelling. In particular, hydrogel derived from an extracellular matrix is widely used in the field of biosynthesis and regenerative medicine because of its excellent biocompatibility and therapeutic effectiveness¹. Hydrogels have been reported for the treatment of gastric ulcers, neuritis, myocardial infarction^2,3,4, and other diseases. Further, it has been proved that gelatin-NB can promote the outcome of inflammation ininflammatory bowel disease (IBD)⁵. Traditiona....

Protocol

The C57BL/6 mice were purchased from Zhejiang University School of Medicine Sir Run Run Shaw Hospital. The New Zealand rabbits were purchased from Zhejiang University. The animals were maintained in natural light-dark cycle conditions and given food and drinking water freely. All experimental procedures were approved ethically by the institutional guidelines of the Zhejiang University Ethics Committee standard guidelines (ZJU20200156) and Zhejiang University School of Medicine Sir Run Run Shaw Hospital Animal Care and Us.......

Discussion

Adhesive materials are a new class of material. More and more researchers are committed to the synthesis of various types of adhesive materials, and are trying to find their applications in biotechnology, tissue engineering, regenerative medicine, and other fields, which has led to vigorous development in recent years. In addition to focusing on the strong adhesion of adhesive materials, researchers are also paying more attention to other properties, such as injectability, self-healing, hemostatic, antibacterial, control.......

Materials

Name	Company	Catalog Number	Comments
1-(3Dimethylaminopropyl)-3-ethylcarbodimide hydrochloride (EDC)	Aladdin	L287553
4-Hydroxy-3-(methoxy-D3) benzaldehyde	Shanghai Acmec Biochemical Co., Ltd	H946072
DCM	Aladdin	D154840
Dichloromethane	Sigma-Aldrich	270997
Dimethyl sulfoxide (DMSO)	Sigma-Aldrich	20-139
dimethylformamide (DMF)	Sigma-Aldrich	PHR1553
gelatin	Sigma-Aldrich	1288485
magnesium sulfate	Sigma-Aldrich	M7506
MeOH	Sigma-Aldrich	1424109
methyl 4-(4-formyl-2-methoxyphenoxy methoxyphenyl) butanoic acid methyl ester	chemsrc	141333-27-9
methyl 4-bromobutyrate	Aladdin	M158832
NaBH4	Sigma-Aldrich	215511
N-hydroxysuccinimide (NHS)	Aladdin	D342712
nitric acid	Sigma-Aldrich	225711
potassium carbonate	Sigma-Aldrich	209619
SEM (Nova Nano 450)	Thermo FEI	17024560
THF/EtOH	Aladdin	D380010
trifluoroacetic acid (TFA)	Sigma-Aldrich	8.0826