Adhesion characteristics of porcine pancreatic islets and exocrine tissue to coating materials

Abstract

Since the report of the Edmonton protocol in 2000, islet transplantation has been implemented worldwide, and xenotransplantation using porcine islets has also been reported. In addition, many basic experiments using pancreatic islets and exocrine tissue after isolation have been reported. Recently, exocrine cells have been found to be essential for inducing the differentiation of pancreatic islets. Therefore, the importance of the culture conditions for pancreatic tissue when conducting experiments using pancreatic tissue is also increasing. In this study, we focused on the coat material and examined the adhesive properties of porcine pancreatic islets and exocrine tissue after isolation. Porcine islet isolation was performed, and isolated islets (purity ≥95%) and exocrine tissue (purity ≥99%) were used to achieve adhesion to several extracellular matrixes, fibronectin, collagen type I, collagen type IV, laminin I, fibrinogen, and bovine serum albumin (BSA). DMEM with 0.5% FBS was used as the assay medium. For exocrine tissue, the adhesion was promoted in fibronectin, collagen type I, laminin I, and fibrinogen. The adhesive ability to fibronectin was more than twice that to BSA, while the adhesive ability to collagen type I, laminin I, and fibrinogen was less than twice that to BSA. For islets, the adhesive ability to fibronectin was weaker than that of exocrine tissue. Furthermore, the adhesion effect in fibronectin was obtained within 30 minutes and in medium containing little serum for both islets and exocrine tissues. These data suggest that fibronectin may be useful for the adhesion of pancreatic tissue.

Culture on a native bone marrow‐derived extracellular matrix restores the pancreatic islet basement membrane, preserves islet function, and attenuates islet immunogenicity

“…We included fibronectin for comparison purposes because it has been implicated in promoting the retention of islet function. 30,31 Our results suggest that the 3D-ECM enhances islet attachment and promotes cell survival (eg, fewer dead cells) (Figure 1). In contrast, in TCP cultures <20% of the islets attached and many islets (>60%) contained a considerable number of dead cells.…”

“…We compared the adhesion of freshly isolated islets to TCP or TCP coated with fibronectin or 3D‐ECM. We included fibronectin for comparison purposes because it has been implicated in promoting the retention of islet function 30,31 . Our results suggest that the 3D‐ECM enhances islet attachment and promotes cell survival (eg, fewer dead cells) (Figure 1).…”

“…Moreover, both adherent and nonadherent islets maintained on 3D-ECM contained fewer dead cells than those maintained on TCP (Figure 1C,D). Since fibronectin has been reported to improve islet attachment and viability, 30,31 we coated this matrix molecule onto TCP for comparison purposes and found that it improved islet attachment and viability better than TCP, but not as well as 3D-ECM. To compare the effect of culture substrate on islet ultrastructure, morphometric analysis of TEM photomicrographs was performed.…”

The Roles of Collagen in Islet Transplantation

“…Furthermore, Beenken-Rothkopf et al conducted a similar study using MIN6 β cells embedded in polymer and showed that collagen IV improved the insulinreleasing function of the cells, the same as other ECMs such as laminin and fibronectin [47]. Other previous studies also revealed the contribution of collagen IV in greater insulin release of islets [44,48,54,56,60], and the therapeutic effects were better than those of other ECMs [44]. Collagen IV also contributed to islet cell survival, prevention of apoptosis, and oxygen consumption rate of immunoisolating encapsulated islets [41,42].…”

Adhesion Characteristics of Human Pancreatic Islets, Duct Epithelial Cells, and Acinar Cells to a Polymer Scaffold

“…We previously performed an assay using porcine islets and reported that fibronectin promotes cell adhesion and the survival of islets 49 . In the present study, we investigated the effect of fibronectin on cell adhesion and the survival of three types of cells derived from the pancreas using a polymer scaffold (fibronectin motif) containing the RGD sequence motif, which consists of three consecutive motifs of R (arginine), G (glycine), and D (aspartate) in the amino acid sequences of fibronectin and vitronectin.…”