Table 2.

Different chemical methods used for cardiac tissue decellularization.

Chemical Decellularization Techniques	Mechanism	General Disadvantages	Study Findings
Ionic detergents (SDS)	breaks non-covalent bonds	aggressive treatment cytotoxic; it requires vigorous rinsing	no intact cells or nuclei were detected in 1% SDS-treated rat hearts for 12 h, with preserved fiber composition and orientation [11] perfusion of porcine hearts with 4% SDS for 12 h lacked intracellular components but retained specific collagen fibers, proteoglycan, elastin, and mechanical integrity [16] decellularization of porcine hearts by repeated washing with 0.5% SDS resulted in 98% DNA removal with only 6 h of detergent exposure [18] 9 h treatment with 0.5% SDS of human left ventricular myocardium showed a pronounced reduction of major matrix components compared to the 3-step protocol (2 h lysis, 6 h 0.5% SDS, and 3 h FBS) [21] 24 h of 0.1% SDS treatment of porcine valve conduits was reported to be effective in cell removal but susceptible to recellularization with human cells [83] low SDS concentration for a limited time (0.5% SDS, 5.5 h) delivered acellular heart constructs (13.1 ± 5.8 ng/mg residual DNA) with maintained cytocompatibility (reseeded with human bone marrow-MSCs) [84] porcine aortic and pulmonary roots treated with different concentrations of SDS removed cells completely but caused strong structural alterations [93] an optimized 1% SDS-based decellularization protocol obtained acellular cardiac scaffolds with applicability to generate vascularized cardiac patches [94]
Non-ionic detergents (Triton X-100)	solubilizes cell membranes, disrupting lipid-lipid and lipid-protein connections	less effective in removing cellular debris	rat hearts treated with Triton X-100 for 12 h showed incomplete decellularization [11] decellularization of porcine hearts with 3% Triton X-100 resulted in incomplete decellularization with only 40% DNA removal [79] 48 h treatment with 5% Triton X-100 damaged the tissue architecture of the human myocardium but was not sufficient to remove cellular material [21]
Acids and bases	solubilize cytoplasmic elements, disrupting nucleic acids	frequently aggressive toward the proteins of the ECM mainly used in combination with other decellularization agents PAA increases ECM stiffness	submillimeter diameter vascular scaffolds decellularized with 0.3% PAA proved patent in rat allogeneic transplantation model for 2 weeks, followed by graft rupture [86] bovine pericardium pretreatment by reversible alkaline swelling (RAS) produced a severe reduction in GAGs and stress relaxation ratios [87]
Hypertonic and hypotonic treatments	induce cell lysis by osmotic shock	inadequate cellular removal ineffective for whole organ decellularization	hyper/hypotonic treatment alone for 72 h of human myocardium damaged the ECM and showed incomplete decellularization [21]
Organic solvents (ethanol)	dehydrates and lyses cells	potential damage to the ECM microstructure	ethanol pretreatment of bioprosthetic heart valves led to unexpectedly cuspal calcification [92]