Interindividual heterogeneity affects the outcome of human cardiac tissue decellularization

Miguel F Tenreiro,Tomás Calmeiro,Paula M Alves,Margarida Serra,Lino Ferreira,Elvira Fortunato,Henrique V Almeida

doi:10.1038/s41598-021-00226-5

Abstract

The extracellular matrix (ECM) of engineered human cardiac tissues corresponds to simplistic biomaterials that allow tissue assembly, or animal derived off-the-shelf non-cardiac specific matrices. Decellularized ECM from human cardiac tissue could provide a means to improve the mimicry of engineered human cardiac tissues. Decellularization of cardiac tissue samples using immersion-based methods can produce acceptable cardiac ECM scaffolds; however, these protocols are mostly described for animal tissue preparations. We have tested four methods to decellularize human cardiac tissue and evaluated their efficiency in terms of cell removal and preservation of key ECM components, such as collagens and sulfated glycosaminoglycans. Extended exposure to decellularization agents, namely sodium dodecyl sulfate and Triton-X-100, was needed to significantly remove DNA content by approximately 93% in all human donors. However, the biochemical composition of decellularized tissue is affected, and the preservation of ECM architecture is donor dependent. Our results indicate that standardization of decellularization protocols for human tissue is likely unfeasible, and a compromise between cell removal and ECM preservation must be established in accordance with the scaffold’s intended application. Notwithstanding, decellularized human cardiac ECM supported human induced pluripotent-derived cardiomyocyte (hiPSC-CM) attachment and retention for up to 2 weeks of culture, and promoted cell alignment and contraction, providing evidence it could be a valuable tool for cardiac tissue engineering.

Highlights

A was already reported for decellularization of micrometric sheets (~ 300 μm) of human myocardium biopsies and used a low percentage of sodium dodecyl sulfate (SDS) (0.5%) for 6 h followed by a washing step with FBS14 (Fig. 1a)
We aimed at evaluating several methods to efficiently decellularize human cardiac tissue, and test if the tissue scaffold could be used for tissue engineering
Among the factors that need to be considered when using this approach is tissue thickness. This provides reasoning why Method A, that was implemented on micrometer thick myocardium s lices[14], was ineffective to decellularize ~ 1 mm thick tissue pieces, that understandably have a higher cell density

Summary

Evaluation of decellularization protocols

Myocardium, LV; No pathology associated Decellularization Method D; Recellularization with hiPSC-CM. Perfusion-based decellularization protocols are suitable to decellularize postmortem hearts unfit for transplantation but difficult to use accurately to decellularize tissue samples from cardiac biopsies, that are more obtained from human donors undertaking interventional surgery. These tissue samples can be decellularized with the same decellularization agents using agitation instead, but established protocols in small or large animals may prove difficult to adapt to human tissue without additional m odifications[10,11]. Besides customization of decellularization protocols for human usage, the heterogeneity between donors might prevent their standardization. We evaluated how effective these previous protocols are to decellularize human cardiac tissue in three unrelated human donor samples and assessed the suitability of the decellularized scaffold to support the culture of cardiomyocytes derived from human induced pluripotent stem cells for application in cardiac tissue bioengineering

Materials and methods

Results

Discussion