Islet microencapsulation is an attractive strategy for the minimization or avoidance of life-long immunosuppression after transplantation. However, the clinical implementation of this technique is currently limited by incomplete biocompatibility. Thus, the aim of the present study was to demonstrate the improved biocompatibility of rapamycin-containing polyethylene glycol (Rapa-PEG)-coating on alginate microcapsules containing xenogeneic islets. The Rapa-PEG-coating on the alginate layer was observed using scanning electron microscopy (SEM) and the molecular cut-off weight of the microcapsules was approximately 70 kDa. The viabilities of the alginate-encapsulated and Rapa-PEG-coated alginate-encapsulated islets were lower than the viability of the naked islets just after encapsulation, but these the differences diminished over time in culture dishes. Rapa-PEG-coating on the alginate capsules effectively decreased the proliferation of macrophage cells compared to the non-coating and alginate coating of xenogeneic pancreas tissues. Glucose-stimulated insulin secretion did not significantly differ among the groups prior to transplantation. The random blood glucose levels of diabetic mice significantly improved following the transplantation of alginate-encapsulated and Rapa-PEG-coated alginate-encapsulated islets, but there were no significant differences between these two groups. However, there was a significant decrease in the number of microcapsules with fibrotic cell infiltration in the Rapa-PEG-coated alginate microcapsule group compared to the alginate microcapsule group. In conclusion, Rapa-PEG-coating might be an effective technique with which to improve the biocompatibility of microcapsules containing xenogeneic islets. Copyright © 2015 John Wiley & Sons, Ltd.
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http://dx.doi.org/10.1002/term.2029 | DOI Listing |
Toxicol Mech Methods
January 2025
Department of Life Sciences, of the University of Coimbra, Coimbra, Portugal.
Mitochondria are affected by chemical substances and play a critical role in drug-induced liver injury (DILI). Chemical substances can have a significant impact on various cellular processes, such as the disruption of oxidative phosphorylation, oxidative stress, and alteration of glucose metabolism. Given the consequences of these effects, it is crucial to understand the molecular pathways of chemical substances in the context of hepatotoxicity to prevent and treat DILI.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Federal University of Pernambuco (UFPE), Av. Profª Morais Rego, 1235, University City, 50670-901 Recife, Brazil; Keizo Asami Institute (iLIKA), Av. Prof. Morais Rego, 1235, University City, 50670-901 Recife, Brazil. Electronic address:
The microencapsulation of Lactocaseibacillus rhamnosus GG in a matrix of sodium alginate, xanthan gum, gum arabic and chitosan hydrochloride is a promising strategy for protecting this probiotic during passage through the gastrointestinal tract. This study evaluated the influence on the viability of Lactocaseibacillus rhamnosus GG encapsulated with these polymers by external ionic gelation with vibratory extrusion and the microcapsules that showed the best results of capsulation efficiency, viability, size and morphology were analyzed by Fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA) and exposure to environmental stress conditions and gastrointestinal simulation. The result revealed encapsulation efficiency values above 95 % for all formulations and survival rate higher than 6 log CFU/mL for most analyzed groups.
View Article and Find Full Text PDFSci Rep
December 2024
Laboratório de Entomologia e Fitopatologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Rio de Janeiro, 28013-602, Brazil.
The virulence of encapsulated fungal conidia against Aedes aegypti larvae was investigated. Molecular studies confirmed that the fungal isolate used here was Beauveria bassiana. Different conidial concentrations were tested.
View Article and Find Full Text PDFJ Colloid Interface Sci
December 2024
Department of Chemical and Biomolecular Engineering, Case School of Engineering, Case Western Reserve University, Cleveland, OH 44106, United States.
We present a study combining experimental measurements, theoretical analysis, and simulations to investigate core-shell microcapsules interacting with a solid boundary, with a particular focus on understanding the short-range potential energy well arising from the tethered force. The microcapsules, fabricated using a Pickering emulsion template with a cinnamon oil core and calcium alginate shell, were characterized for size (∼5-6μm in diameter) and surface charge (∼-20mV). We employed total internal reflection microscopy and particle tracking to measure the microcapsule-boundary interactions and diffusion, from which potential energy and diffusivity profiles were derived.
View Article and Find Full Text PDFAdv Sci (Weinh)
December 2024
Division of Hepatobiliary and Transplantation Surgery, Department of General Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, 210008, China.
Human induced pluripotent stem cell derived hepatocytes (hiPSC-heps) hold promising value for acute liver failure (ALF) treatment, while their therapeutic efficacy is usually limited by low cell bioactivity and untargeted in vivo accumulation. Here, inspired by vascularity supporting cellular architectures in the tissues and organs, a novel vascularized hiPSC-heps spheroid based on microfluidic microcapsules is presented for liver repair via orthotopic transplantation. The microcapsules are comprised of aqueous cores that facilitate hiPSC-hep aggregating into spheroids, and hybrid hydrogel shells of sodium alginate and hyaluronic acid methacryloyl (HAMA).
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