In Vitro Evaluation of Type I Collagen-Based Scaffolds After Applying Different Sterilization Techniques

Purpose

Tissue engineering provides alternative solutions e.g. developing bioactive and biodegradable constructs (scaffolds) which allow tissue regeneration. To find the ultimate sterilization method for these protein-based materials is rather challenging. The aim of this study was to sterilize type I collagen-based scaffolds using different sterilization techniques and evaluated with urothelial cell culture to assess the bioactivity and biocompatibility.

Material And Methods

Scaffolds were prepared from type I collagen and crosslinked with and without heparin. The scaffolds were disinfected with ethanol or sterilized by means of β-radiation or ethylene oxide gas. The constructs were characterized with Scanning Electron Microscopy (SEM), immunofluorescence staining (IFA) and biochemical assays. An urothelial cell line was seeded on the scaffolds and cultured for 3, 7 and 14 days. Cultured scaffolds were evaluated with cell proliferation test (WST-1), SEM and Hematoxylin & Eosin staining (H&E).

Results

Different crosslinking methods resulted in differences in the degree of crosslinking and localization of heparin. Although scaffolds were sterilized, the heparin binding growth factor VEGF could be bound to the incorporated heparin. The cell cultured scaffolds revealed a trend in compatibility. β-radiated scaffolds showed higher cell proliferation then ethylene oxide sterilized scaffolds. The heparin scaffolds showed a decrease in cell proliferation.

Conclusions

β-radiation sterilized scaffolds showed the best cell morphology and proliferation. β-radiation or ethylene oxide gas sterilization did not affect heparin binding. Considering upscale manufacturing of off-the-shelve products and the empirical data from this investigation, we conclude that β-radiation is the most suitable technique.

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