Post-operative pancreatic fistula (POPF) following pancreatic resection is a life-threatening surgical complication. Cell sheets were prepared and harvested using temperature-responsive culture dishes and transplanted as patches to seal POPF. Two different mesenchymal stem cell (MSC) sheets were compared in terms of the preventative ability for pancreatic leakage in a rat model. Both rat adipose-derived stem cell (rADSC) and bone marrow-derived stem cell (rBMSC) sheets were transplanted. Those rADSC and rBMSC sheets are created without enzymes and thus maintained their cell-cell junctions and adhesion proteins with intact fibronectin on the basal side, as well as characteristics of MSCs. The rats with post-pancreatectomy rADSC- or rBMSC-sheet patches had significantly decreased abdominal fluid leakage compared with the control group, demonstrated by MR image analysis and measurement of the volume of abdominal fluid. Amylase level was significantly lower in the rats with rADSC-sheet and rBMSC-sheet patches compared with the control groups. The rADSC sheet patches had increased adhesive and immune-cytokine profiles (ICAM-1, L-selectin, TIMP-1), and the rBMSC sheets had reduced immune reactions compared to the control. This is first project looking at the feasibility of tissue engineering therapy using MSC-sheets as tissue patches preventing leakage of abdominal fluid caused by POPF.
The combination of GSK2126458 and AZD6244 blocks both the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR pathways simultaneously and is an effective strategy for the treatment of CRPCs.
In combination with 5-fluorouracil the targeted inhibitor of histone deacetylase synergistically inhibited renal cancer cell growth by the blockade of thymidylate synthase induction and the induction of reactive oxygen species mediated DNA damage in vitro and in vivo. Our results suggest that combined treatment with belinostat and 5-fluorouracil may represent a promising new approach to renal cancer.
Islet cell transplantation is considered an ideal treatment for insulin-deficient diabetes, but implantation sites are limited and show low graft survival. Cell sheet technology and adipose-derived stem cells (ADSCs) can be useful tools for improving islet cell transplantation outcomes since both can increase implantation efficacy and graft survival. Herein, the optimal transplantation site in diabetic mice was investigated using islets and stem cell sheets. We constructed multi-layered cell sheets using rat/human islets and human ADSCs. Cell sheets were fabricated using temperature-responsive culture dishes. Islet/ADSC sheet (AI sheet) group showed higher viability and glucose-stimulated insulin secretion than islet-only group. Compared to islet transplantation alone, subcutaneous AI sheet transplantation showed better blood glucose control and CD31+ vascular traits. Because of the adhesive properties of cell sheets, AI sheets were easily applied on liver and peritoneal surfaces. Liver or peritoneal surface grafts showed better glucose control, weight gain, and intraperitoneal glucose tolerance test (IPGTT) profiles than subcutaneous site grafts using both rat and human islets. Stem cell sheets increased the therapeutic efficacy of islets in vivo because mesenchymal stem cells enhance islet function and induce neovascularization around transplanted islets. The liver and peritoneal surface can be used more effectively than the subcutaneous site in future clinical applications.
To obtain improved efficacy against pancreatic cancer, we investigated the efficacy and safety of a locally-applied 5-fluorouracil (5-FU)-loaded polymeric patch on pancreatic tumors in an orthotopic nude-mouse model. The 5-FU-releasing polymeric patch was produced by 3D printing. After application of the patch, it released the drug slowly for 4 weeks, and suppressed BxPC-3 pancreas cancer growth. Luciferase imaging of BxPC3-Luc cells implanted in the pancreas was performed longitudinally. The drug patch delivered a 30.2 times higher level of 5-FU than an intra-peritoneal (i.p.) bolus injection on day-1. High 5-FU levels were accumulated within one week by the patch. Four groups were compared for efficacy of 5-FU. Drug-free patch as a negative control (Group I); 30% 5-FU-loaded patch (4.8 mg) (Group II); 5-FU i.p. once (4.8 mg) (Group III); 5-FU i.p. once a week (1.2 mg), three times (Group IV). The tumor growth rate was significantly faster in Group I than Group II, III, IV (p=0.047 at day-8, p=0.022 at day-12, p=0.002 at day-18 and p=0.034 at day-21). All mice in Group III died of drug toxicity within two weeks after injection. Group II showed more effective suppression of tumor growth than Group IV (p=0.018 at day-12 and p=0.017 at day-21). Histological analysis showed extensive apoptosis in the TUNEL assay and by Ki -67 staining. Western blotting confirmed strong expression of cleaved caspase-3 in Group II. No significant changes were found hematologically and histologically in the liver, kidney and spleen in Groups I, II, IV but were found in Group III.
Background Although pancreatic islet transplantation therapy is ideal for diabetes patients, several hurdles have prevented it from becoming a standard treatment, including donor shortage and low engraftment efficacy. In this study, we prepared insulin-producing cells trans-differentiated from adult human liver cells as a new islet source. Also, cell sheet formation could improve differentiation efficiency and graft survival. Methods Liver cells were expanded in vitro and trans-differentiated to IPCs using adenovirus vectors carrying human genes for PDX1, NEUROD1, and MAFA. IPCs were seeded on temperature-responsive culture dishes to form cell sheets. Differentiation efficiency was confirmed by ß cell-specific gene expression, insulin production, and immunohistochemistry. IPC suspension was injected by portal vein (PV), and IPC sheet was transplanted on the liver surface of the diabetic nude mouse. The therapeutic effect of IPC sheet was evaluated by comparing blood glucose control, weight gain, histological evaluation, and hepatotoxicity with IPC injection group. Also, cell biodistribution was assessed by in vivo/ex vivo fluorescence image tagging. Results Insulin gene expression and protein production were significantly increased on IPC sheets compared with those in IPCs cultured on conventional culture dishes. Transplanted IPC sheets displayed significantly higher engraftment efficiency and fewer transplanted cells in other organs than injected IPCs, and also lower liver toxicity, improved blood glucose levels, and weight gain. Immunohistochemical analyses of liver tissue revealed positive staining for PDX1 and insulin at 1, 2, and 4 weeks after IPC transplantation. Conclusions In conclusion, cell sheet formation enhanced the differentiation function and maturation of IPCs in vitro. Additionally, parameters for clinical application such as distribution, therapeutic efficacy, and toxicity were favorable. The cell sheet technique may be used with IPCs derived from various cell sources in clinical applications.
Background: Although pancreatic islet transplantation therapy is ideal for diabetes patients, several hurdles have prevented it from becoming a standard treatment, including donor shortage and low engraftment efficacy. In this study, we prepared insulin-producing cells trans-differentiated from adult human liver cells as a new islet source. Also, cell sheets formation could improve differentiation efficiency and graft survival.Methods: Liver cells were expanded in vitro and trans-differentiated to IPCs using adenovirus vectors carrying human genes for PDX1, NEUROD1 and MAFA. IPCs were seeded on temperature-responsive culture dishes to form cell sheets. Differentiation efficiency were confirmed by ß cell-specific gene expression, insulin production, and immunohistochemistry. IPCs suspension was injected by portal vein (PV), and IPCs sheet was transplanted on the liver surface of the diabetic nude mouse. The therapeutic effect of IPC sheet was evaluated by comparing blood glucose control, weight gain, histological evaluation and hepatotoxicity with IPCs injection group. Also, cell biodistribution was assessed by in vivo/ex vivo fluorescence image tagging.Results: Insulin gene expression and protein production were significantly increased on IPC sheets compared with those in IPCs cultured on conventional culture dishes. Transplanted IPC sheets displayed significantly higher engraftment efficiency and fewer transplanted cells in other organs than injected IPCs, and also lower liver toxicity, improved blood glucose levels, and weight gain. Immunohistochemical analyses of liver tissue revealed positive staining for PDX1 and insulin at 1, 2 and 4 weeks after IPCs transplantation.Conclusions: In conclusion, cell sheet formation enhanced the differentiation function and maturation of IPCs in vitro. Additionally, parameters for clinical application such as distribution, therapeutic efficacy, and toxicity were favorable. The cell sheet technique may be used with IPCs derived from various cell sources in clinical applications.
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