Pancreatic bioengineering is a potential therapeutic alternative for type 1 diabetes (T1D) in which the pancreas is decellularized, generating an acellular extracellular matrix (ECM) scaffold, which may be reconstituted by recellularization with several cell types to generate a bioartificial pancreas. No consensus for an ideal pancreatic decellularization protocol exists. Therefore, we aimed to determine the best-suited detergent by comparing sodium dodecyl sulfate (SDS), sodium deoxycholate (SDC), and Triton X-100 at different concentrations. Murine (n=12) and human pancreatic tissue from adult brain-dead donors (n=06) was harvested in accordance with Institutional Ethical Committee of the University of São Paulo Medical School (CEP-FMUSP) and decellularized under different detergent conditions. DNA content, histological analysis, and transmission and scanning electron microscopy were assessed. The most adequate condition for pancreatic decellularization was found to be 4% SDC, displaying: a) effective cell removal; b) maintenance of extracellular matrix architecture; c) proteoglycans, glycosaminoglycans (GAGs), and collagen fibers preservation. This protocol was extrapolated and successfully applied to human pancreas decellularization. The acellular ECM scaffold generated was recelullarized using human pancreatic islets primary clusters. 3D clusters were generated using 0.5×104 cells and then placed on top of acellular pancreatic slices (25 and 50 μm thickness). These clusters tended to connect to the acellular matrix, with visible cells located in the periphery of the clusters interacting with the ECM network of the bioscaffold slices and continued to produce insulin. This study provided evidence on how to improve and accelerate the pancreas decellularization process, while maintaining its architecture and extracellular structure, aiming at pancreatic bioengineering.
23 October 2023 in International Archives of Otorhinolaryngology
Introduction The nonspecific hyperreactivity of rhinitis has been attributed to neurotrophins activating sensory nerves and inflammatory cells. The relationship between these markers and the intensity of the symptoms is not well established and few studies have evaluated individuals with idiopathic rhinitis. Objective The present study aims to evaluate whether perivascular innervation and nerve growth factor (NGF) are related to the intensity of the clinical conditions in allergic rhinitis (AR) and idiopathic rhinitis (IR). Methods A total of 15 patients with AR and 15 patients with IR with the indication for inferior turbinectomy (associated or not with septoplasty) were selected. The patients received a score according to their signs and symptoms. After the surgery, we quantified eosinophils, mast cells, NGF, and nerve fibers in the nasal turbinate. Results The score of the signs and symptoms was higher in the AR group. Nerve growth factor was found in the cytoplasm of inflammatory cells in the submucosa in greater quantity in the AR group. The nerve fibers were distributed throughout the tissue, mainly in the subepithelial, glandular, and vascular regions, and there was no difference between the groups. Greater perivascular innervation was associated with a higher signs and symptoms score. Conclusions We concluded that these findings suggest that the NGF produced by submucosal inflammatory cells stimulates increased perivascular innervation in rhinitis, thus directly reflecting in more intense clinical conditions, especially in AR.