Perfusion decellularization of human and porcine lungs: bringing the matrix to clinical scale

Abstract

Background: Organ engineering is a theoretical alternative to allotransplantation for end-stage organ failure. Whole-organ scaffolds can be created by detergent perfusion via the native vasculature, generating an acellular matrix suitable for recellularization with selected cell types. We aimed to up-scale this process, generating biocompatible scaffolds of a clinically relevant scale.

Methods: Rat, porcine, and human lungs were decellularized by detergent perfusion at constant pressures. Collagen, elastin, and glycosaminoglycan content of scaffolds were quantified by colorimetric assays. Proteomic analysis was performed by microcapillary liquid chromatography tandem mass spectrometry. Extracellular matrix (ECM) slices were cultured with human umbilical vein endothelial cells (HUVEC), small airway epithelial cells (SAEC), or pulmonary alveolar epithelial cells (PAECs) and evaluated by time-lapse live cell microscopy and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Whole-organ culture was maintained under constant-pressure media perfusion after seeding with PAECs.

Results: Rat lungs were decellularized using: (1) sodium dodecyl sulfate (SDS), (2) sodium deoxycholate (SDC), or (3) 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). Resulting scaffolds showed comparable loss of DNA but greatest preservation of ECM components in SDS-decellularized lungs. Porcine (n = 10) and human (n = 7) lungs required increased SDS concentration, perfusion pressures, and time to achieve decellularization as determined by loss of DNA, with preservation of intact matrix composition and lung architecture. Proteomic analysis of human decellularized lungs further confirmed ECM preservation. Recellularization experiments confirmed scaffold biocompatibility when cultured with mature cell phenotypes and scaffold integrity for the duration of biomimetic culture.

Conclusions: SDS-based perfusion decellularization can be applied to whole porcine and human lungs to generate biocompatible organ scaffolds with preserved ECM composition and architecture.

Keywords: acellular matrix; decellularization; organ engineering; organ scaffolds; recellularization.