Surface-modified gelatin hydrogel scaffolds with imprinted microgrooves: physical characterization and study on endothelial cell interaction.

Abstract

Endothelialization of biomaterials enhances biocompatibility, hemocompatibility, and reduces inflammatory responses in blood-contacting materials. Surface topographies, particularly groove-like structures, influence endothelial cell morphology and function. This study investigates the impact of microgroove dimensions on endothelialization in gelatin hydrogel scaffolds, alongside assessing their physical and mechanical properties. Using sequential replications, six microgroove geometries with widths ranging from 2.86 µm to 84.20 µm and depths from 284 nm to 919 nm were fabricated on gelatin hydrogel. Surface characterization of the scaffolds over 5 days using confocal microscopy revealed a shrinkage followed by dimensional stability after 24 h. Tensile testing after conditioning in cell culture environments showed Young's modulus of 327.2-529.5 kPa comparable to natural blood vessels. Cultivation of human endothelial cells demonstrated improved cell orientation and elongation on microstructured surfaces. Notably, two specific microgrooved scaffolds (9.33 µm width, 599 nm depth and 22.27 µm width, 919 nm depth) enhanced cell proliferation, adhesion and accelerated confluent monolayer formation as confirmed through fluorescent staining for cell nuclei, Vinculin, and VE-cadherin expression, respectively. This study identifies optimal microgroove dimensions for surface modification of gelatin hydrogel scaffolds demonstrating how geometric cues can positively impact cell morphology and function. This surface engineering approach has a potential application in in vitro endothelialized models for cardiovascular research as well as in vascular implants for tissue remodeling.