Heterotopic vascularization and functionalization of implantable bio engineered hepatic tissue alleviates liver injury in rats

Abstract

Background The challenge of using bioengineered liver lies in sustaining the quantity of high‐quality hepatocytes and the vasculature for blood perfusion. We characterized the heparinization of a porcine decellularized liver scaffold (DLS) as a carrier to support hepatocyte angiogenesis, thereby developing functional and vascularized hepatic tissue useful to treat liver injury. Method The porcine DLS was obtained by the removal of cellular components and then subjected to heparinization by the end‐point attachment technique. The heparinized DLSs were recellularized with rat hepatocyte spheroids to construct engineered hepatic tissue. The hepatic tissue was heterotopically implanted in the omentum majus of a rat model with liver injury induced by carbon tetrachloride (CCl4). Results Hepatocyte spheroids in the heparinized DLS remained viable for at least 10 weeks in vivo. The entire scaffold was populated with hepatocytes and arranged well. The volume of the heparinized DLS group was expanded over 400‐fold. Liver‐specific functions such as albumin synthesis, glycogen storage and cytochrome P 3A4 activity were highly expressed in the hepatic tissue. In addition, endothelial cells were recruited, as shown by CD31 staining, and new blood vessels formed, as visualized by fluorescein isothiocyanate‐labelled dextran intravital confocal microscopy. The heparinized bioengineered hepatic tissue alleviated CCl4‐induced liver injury by regulating the deposition and degradation of the extracellular matrix. Conclusion Primary hepatocyte spheroids survived for an extended time on the heparinized DLS and expanded to generate vascularized and functional bioengineered hepatic tissue that can alleviate liver injury in rats.

Liver scaffolds obtained by decellularization: A transplant perspective in liver bioengineering

“…The scaffold functionality was observed 48 and 72 h post-transplantation decreasing aspartate transaminase (AST) levels and increasing albumin (ALB) levels in recipient animals’ serum. Li et al 131 transplanted bioengineered hepatic tissues in the omentum majus of recipient mice treated with CCl 4 7 days before transplantation. The authors observed that recellularized liver graft was able to improve the recipient’s serological parameters (decreasing AST, total bilirubin levels, and increasing albumin ALB levels) and also ameliorated native liver fibrogenesis.…”

“…As far as we know, a few descriptions of ex vivo bioengineered liver transplantation in the recipient liver disease model were published. 129 – 131 Probably, it can be explained by the difficulty of reaching long-term survival taxes after transplantation. A substantial number of animal models with liver disease already have a high mortality rate during the time of induction, which hinders their surgical performance resulting in short-term survival taxes.…”

Functionalized Vascular Structure in Bioengineered Liver Identified with Proteomics

“…The recellularization of DLS has led to the construction of functional bioengineered livers in vitro. 3,4 However, the vascularization of DLS remains a major challenge in engineering a transplantable liver. Constructing a functional vasculature in DLS is crucial for nutrient and oxygen delivery.…”

“…Decellularized liver scaffold (DLS) with intact vascular networks and extracellular matrices (ECMs) is a promising material for engineering functional organs. The recellularization of DLS has led to the construction of functional bioengineered livers in vitro. , However, the vascularization of DLS remains a major challenge in engineering a transplantable liver. Constructing a functional vasculature in DLS is crucial for nutrient and oxygen delivery.…”

Cell Therapy and Bioengineering in Experimental Liver Regenerative Medicine: In Vivo Injury Models and Grafting Strategies

“…These forms are fabricated using digested ECM, homogenized ECM, or ECM ink, respectively. These ECM forms could be used for cell delivery, but they have relevant limitations, mainly due to the additional loss of biochemical components during the digestion and fabrication processes [97,[109][110][111][112][113][114][115][116].…”