Assessment of various crosslinking agents on collagen/chitosan scaffolds for myocardial tissue engineering.

Abstract

Suitable material for scaffolds that support cell attachment, proliferation, vascularization and contraction has always been a challenge in myocardial tissue engineering. Much research effort has been focused on natural polymers including collagen, gelatin, chitosan, fibrin, alginate, etc. Among them, collagen/chitosan composite scaffold was widely used for myocardial tissue engineering. Due to the non-proliferative and contractile characteristics of cardiomyocytes, the biocompatibility and mechanical property of the scaffolds are extremely important for supporting intercellular connection and tissue function for myocardial tissue engineering. To our best knowledge, the three crosslinking agents (glutaraldehyde, genipin, tripolyphosphate) have not yet been comparatively studied in myocardial tissue engineering. Thus, the aim of this study is to compare and identify the crosslinking effect of glutaraldehyde, genipin and tripolyphosphate (TPP) for myocardial tissue engineering. The collagen/chitosan scaffolds prepared with various crosslinking agents were fabricated and evaluated with physical characteristics, biocompatibility and contractile performance. All the groups of scaffolds exhibited high porosity (> 65%) and good swelling ratio suitable for myocardial tissue engineering. TPP crosslinked scaffolds showed the excellent mechanical property with its elastic modulus (81.0 ± 8.1 kPa) in the physiological range of native myocardium (20~100 kPa). Moreover, genipin and TPP crosslinked scaffolds exhibited the better biocompatibility than GTA crosslinked scaffolds as demonstrated by the live/dead staining and proliferation assay. Additionally, cardiomyocytes within TPP crosslinked scaffolds showed the highest expression of cardiac specific marker protein and the best contractile performance. To conclude, of the three crosslinking agents, tripolyphosphate (TPP) was recommended as the most suitable crosslinking agent for collagen/chitosan scaffold in myocardial tissue engineering.