Healing and Angiogenic Properties of Collagen/Chitosan Scaffolds Enriched with Hyperstable FGF2-STAB® Protein: In Vitro, Ex Ovo and In Vivo Comprehensive Evaluation.

Lucy Vojtová,Martin Faldyna,Eva Filová,Veronika Hefka Blahnová,Břetislav Lipový,Katarína Kacvinská,Martin Knoz,Jana Brtníková,Jakub Holoubek,Eduard Göpfert,Veronika Pavliňáková,Monika Vícenová,Johana Muchová,Zdeněk Pavlovský,Vanessa Hearnden

doi:10.3390/biomedicines9060590

Abstract

Wound healing is a process regulated by a complex interaction of multiple growth factors including fibroblast growth factor 2 (FGF2). Although FGF2 appears in several tissue engineered studies, its applications are limited due to its low stability both in vitro and in vivo. Here, this shortcoming is overcome by a unique nine-point mutant of the low molecular weight isoform FGF2 retaining full biological activity even after twenty days at 37 °C. Crosslinked freeze-dried 3D porous collagen/chitosan scaffolds enriched with this hyper stable recombinant human protein named FGF2-STAB® were tested for in vitro biocompatibility and cytotoxicity using murine 3T3-A31 fibroblasts, for angiogenic potential using an ex ovo chick chorioallantoic membrane assay and for wound healing in vivo with 3-month old white New Zealand rabbits. Metabolic activity assays indicated the positive effect of FGF2-STAB® already at very low concentrations (0.01 µg/mL). The angiogenic properties examined ex ovo showed enhanced vascularization of the tested scaffolds. Histological evaluation and gene expression analysis by RT-qPCR proved newly formed granulation tissue at the place of a previous skin defect without significant inflammation infiltration in vivo. This work highlights the safety and biocompatibility of newly developed crosslinked collagen/chitosan scaffolds involving FGF2-STAB® protein. Moreover, these sponges could be used as scaffolds for growing cells for dermis replacement, where neovascularization is a crucial parameter for successful skin regeneration.

Highlights

IntroductionThe skin is the largest organ of the body and represents the outer covering of the human body
Introduction conditions of the Creative CommonsThe skin is the largest organ of the body and represents the outer covering of the human body
The ability of a scaffold to preserve water is an important aspect to evaluate its potential for skin tissue engineering

Summary

Introduction

The skin is the largest organ of the body and represents the outer covering of the human body. Its main function is to provide a barrier between the internal environment of the body and the external agents. The skin is exposed to various injuries. Biomedicines 2021, 9, 590 including mechanical damage, microbiological attacks, and physical and chemical effects, e.g., burns [1]. For the survival of the organism, it is necessary to ensure a suitable regeneration of the skin, whether by natural healing processes or by means of artificial medical interventions. The keratinocytes are the major cell component of the external layer, the epidermis, forming a keratinized stratified squamous epithelium [3]

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Conclusion