sepharose and Insulinoma

A chitosan/gelatin solution with glycerol 2-phosphate disodium salt hydrate in liquid phase at room temperature becomes a hydrogel at 37 degrees C. The material can be used as an injectable cell carrier into the human body for gelation in situ. We hoped that the chitosan/gelatin hydrogel provided extra protection for insulinoma/agarose microspheres during xenogenic transplantation.. Mouse insulinoma was microencapsulated in agarose as microspheres, which were macroencapsulated in chitosan/gelatin hydrogel. Insulin secreting profiles were first demonstrated in vitro. Diabetic rats were injected subcutaneously with insulinoma/agarose microspheres or insulinoma/agarose microspheres suspended in chitosan/gelatin solution. The nonfasting blood glucose concentrations (NFBG) of diabetic rats were measured perioperatively. Rats were humanely killed 1 month postoperatively and the hydrogel was retrieved for histological examination.. The insulinoma/agarose microspheres continually secreted insulin for 1 month when macroencapsulated in chitosan/gelatin hydrogel in vitro. The NFBG of diabetic rats injected with insulinoma/agarose microspheres decreased to euglycemic status albeit hyperglycemia was restored within 10 days. The NFBG of diabetic rats injected with chitosan/gelatin hydrogel, which contained insulinoma/agarose microspheres, was maintained at less than 200 mg/dL for 25 days. The histological section revealed immune cell infiltration and accumulation within the hydrogel and around the iusulinoma/agarose microspheres that may have contributed to the slowly increasing NFBG after day 25.. This study showed that chitosan/gelatin hydrogel can be used as a cell carrier for an injectable bioartificial pancreas; the hydrogel prolonged the function of cells encapsulated in agarose microspheres during xenogenic transplantation.

Topics: Animals; Chitosan; Gelatin; Hydrogels; Insulin; Insulin Secretion; Insulinoma; Mice; Neoplasm Transplantation; Rats; Sepharose; Transplantation, Heterologous

In this study, the feasibility of using calcium phosphate cement (CPC) as immunoisolative device to enclose insulinoma/agarose microspheres as bioartificial pancreas was evaluated. We fabricated a chamber by CPC and utilized X-ray diffraction, Scanning electron microscope and Mercury intrusion porosimetry to identify the characters of the CPC chamber. The nominal molecular weight cut-off and cytotoxicity of CPC chamber were also evaluated. An insulinoma cell line (RIN-m5F) was chosen as insulin source and encapsulated in agarose microspheres and then enclosed in preformed CPC chamber. Insulin secretion was analyzed by Enzyme-linked immunosorbant assay to evaluate the function of insulinoma enclosed in CPC chamber. Results showed that the CPC chamber was non-cytotoxicity to insulinoma and can block the penetration of molecules which molecular weight larger than 12.4 kDa. Insulinoma inside the CPC chamber can secrete insulin in stable level for 30 days. This study indicated that we may use CPC as immunoisolative material to enclose insulinoma/agarose microspheres as bioartificial pancreas.

Topics: Animals; Biomechanical Phenomena; Calcium Phosphates; Cell Line; Equipment Design; Feasibility Studies; Insulin; Insulin Secretion; Insulinoma; Materials Testing; Microscopy, Electron, Scanning; Microspheres; Pancreas, Artificial; Rats; Sepharose

Here, we describe the preparation, structure, and properties of cryogel sponges, which represent a new type of macroporous biomaterial for tissue engineering. Cryogels were produced through freeze-thawing techniques, either from agarose alone or from agarose with grafted gelatin. The aim of this study was to evaluate agarose cryogel sponges as scaffolds for culturing both isolated pancreatic islets and insulinoma cells (INS-1E). In order to evaluate the effect of cell entrapment in artificial scaffolds, cell function reflected by insulin secretion and content was studied in cells cultivated for a 2-week period either in culture plastic plates or in cryogel sponge disks. Our results show that tumor-derived INS-1E cells grown either on plastic or on cryogels do not differ in their proliferation, morphology, insulin release, and intracellular insulin content. However, isolated pancreatic islets cultivated on cryogels sponge show 15-fold higher basal insulin secretion at 3.0 mM glucose than islets cultivated on plastic plates and fail to respond to stimulation with 16.7 mM glucose. In addition, these islets have about 2-fold lower insulin content compared to those grown in plastic plates. It is possible that the cell dysfunction noted in these in vitro experiments is due to the effect of the limited oxygen supply to the islets cultivated in cryogel sponge. Further in vivo studies are needed to clarify the nature of such an observation since according to previous reports, agarose and gelatin induce new vessel formation supporting enhanced oxygen supply.

Topics: Animals; Blood Proteins; Cell Line, Tumor; Cells, Cultured; Cryogels; Fibronectins; Hydrogels; Insulinoma; Islets of Langerhans; Male; Mice; Mice, Inbred ICR; Oxygen Consumption; Sepharose

Topics: Animals; Biocompatible Materials; Blood Glucose; Capsules; Cell Line; Diabetes Mellitus, Experimental; Humans; Insulin Infusion Systems; Insulinoma; Islets of Langerhans Transplantation; Pancreatic Neoplasms; Rats; Rats, Inbred Lew; Sepharose; Transplantation, Heterologous; Tumor Cells, Cultured