The rat pancreatic body tail as a source of a novel extracellular matrix scaffold for endocrine pancreas bioengineering

Abstract Background Regenerative medicine and tissue engineering are promising approaches for organ transplantation. Extracellular matrix (ECM) based scaffolds obtained through the decellularization of natural organs have become the preferred platform for organ bioengineering. In the field of pancreas bioengineering, acellular scaffolds from different animals approximate the biochemical, spatial and vascular relationships of the native extracellular matrix and have been proven to be a good platform for recellularization and in vitro culture. However, artificial endocrine pancreases based on these whole pancreatic scaffolds have a critical flaw, specifically their difficult in vivo transplantation, and connecting their vessels to the recipient is a major limitation in the development of pancreatic tissue engineering. In this study, we focus on preparing a novel acellular extracellular matrix scaffold derived from the rat pancreatic body tail (pan-body-tail ECM scaffold). Results Several analyses confirmed that our protocol effectively removes cellular material while preserving ECM proteins and the native vascular tree. DNA quantification demonstrated an obvious reduction of DNA compared with that of the natural organ (from 931.9 ± 267.8 to 11.7 ± 3.6 ng/mg, P  0.05). After transplanted with the recellularized pancreas, fasting glucose levels declined to 9.08 ± 2.4 mmol/l within 2 h of the operation, and 8 h later, they had decreased to 4.7 ± 1.8 mmol/l (P < 0.05). Conclusions The current study describes a novel pancreatic ECM scaffold prepared from the rat pancreatic body tail via perfusion through the left gastric artery. We further showed the pioneering possibility of in vivo circulation-connected transplantation of a recellularized pancreas based on this novel scaffold. By providing such a promising pancreatic ECM scaffold, the present study might represent a key improvement and have a positive impact on endocrine pancreas bioengineering

A distinct microbiota signature precedes the clinical diagnosis of hepatocellular carcinoma

ABSTRACTOral, gut, and tumor microbiota have been implicated as important regulators in the carcinogenesis and progression of gastrointestinal malignancies. However, few studies focused on the existence and association of resident microbes within different body regions. Herein, we aim to reveal the durability of the oral-gut-tumor microbiome and its diagnostic performance in hepatocellular carcinoma (HCC). Our study included two cohorts: a retrospective discovery cohort of 364 HBV-HCC patients and 160 controls with oral or fecal samples, a prospective validation cohort of 91 cases, and 124 controls for matching samples, as well as 48 HBV, and 39 HBV-cirrhosis patients for gut microbial patterns examined by 16S rRNA gene sequencing. With the random forest analysis, 10 oral and 9 gut genera that could distinguish HCC from controls in the retrospective cohort were validated among the prospective matching participants, with area under the curve (AUC) values of 0.7971 and 0.8084, respectively. When influential taxa were merged, the AUC of the consistent classifier increased to 0.9405. The performance continued to improve to 0.9811 when combined with serum levels of alpha-fetoprotein (AFP). Specifically, microbial biomarkers represented by Streptococcus displayed a constantly increasing trend during the disease transition. Furthermore, the presence of several dominant microbiota species was confirmed in hepatic tumor and non-tumor tissues with fluorescence in situ hybridization (FISH) and 5 R 16S rRNA gene sequencing. Overall, our findings based on the oral-gut-tumor microbiota provide a reliable approach for the early detection of HCC

Additional file 2: of The rat pancreatic body tail as a source of a novel extracellular matrix scaffold for endocrine pancreas bioengineering

Figure S2. In vivo transplantation steps: (A-C) Procedure of recellularized pancreas transplantation. Firstly heparinization was accomplished through the injection of heparin into the inferior vena cava. Nephrectomy on the left kidney was performed with an empty kidney region, and the left renal artery and vein were retained as the grafted vessels. The recellularized pancreas was placed within the kidney region, and the arterial inlet was connected to a peristaltic pump to perfuse heparin sodium solution for several minutes before in vivo transplantation. The outlet of the recellularized scaffold was then connected to the recipient’s renal vein to perfuse the heparin sodium solution for several minutes to avoid thrombosis. The recipient’s renal vein and the inlet of the recellularized scaffold were blocked with vascular clips. The inlet of the recellularized scaffold was subsequently connected to the recipient’s renal artery. Finally, the vascular clips were removed, and whether the blood flow in the recellularized scaffold was unobstructed was observed. The incision was closed after confirmation that there was no bleeding around the transplanted pancreas. (TIFF 8673 kb

Additional file 1: of The rat pancreatic body tail as a source of a novel extracellular matrix scaffold for endocrine pancreas bioengineering

Figure S1. (A) Anatomical structure of the rat pancreas. (B) Schematic diagram of surgical procedures for rat pancreatectomy. (TIFF 2979 kb