Glucose homeostasis changes and pancreatic β-cell proliferation after switching to cyclosporin in tacrolimus-induced diabetes mellitus

AbstractBackgroundSwitching to cyclosporin A may result in a reversion of tacrolimus-induced diabetes mellitus. However, mechanisms underlying such a reversion are still unknown.MethodsObese Zucker rats were used as a model for tacrolimus-induced diabetes mellitus. A cohort of 44 obese Zucker rats received tacrolimus for 11 days (0.3mg/kg/day) until diabetes development; then, (a) 22 rats were euthanized at day 12 and were used as a reference group (tacrolimus-day 12), and (b) 22 rats on tacrolimus were shifted to cyclosporin (2.5mg/kg/day) for 5 days (tacrolimus-cyclosporin). An additional cohort of 22 obese Zucker rats received the vehicle for 17 days and was used as a control group. All animals underwent an intraperitoneal glucose tolerance test at the end of the study.Resultsβ-Cell proliferation, apoptosis and Ins2 gene expression were evaluated. Compared to rats in tacrolimus-day 12 group, those in tacrolimus-cyclosporin group showed a significant improvement in blood glucose levels in all assessment points in intraperitoneal glucose tolerance test. Diabetes decreased from 100% in tacrolimus-day-12 group to 50% in tacrolimus-cyclosporin group. Compared to tacrolimus-day-12 group, rats in tacrolimus-cyclosporin group showed an increased β-cell proliferation, but such an increase was lower than in rats receiving the vehicle. Ins2 gene expressions in rats receiving tacrolimus-cyclosporin and rats receiving the vehicle were comparable.ConclusionAn early switch from tacrolimus to cyclosporin in tacrolimus-induced diabetes mellitus resulted in an increased β-cell proliferation and reversion of diabetes in 50% of cases

Application of stimuli-responsive materials for extraction purposes

Stimuli-responsive materials, frequently designated as “smart/intelligent materials”, can modify their structure or properties by either a biological, physical, or chemical stimulus which, if properly controlled, could be used for specific applications. Such materials have been studied and exploited in several fields, like electronics, photonics, controlled drugs administration, imaging and medical diagnosis, among others, as well as in Analytical Chemistry where they have been used as chromatographic stationary phases, as part of sensors and for extraction purposes. This review article pretends to provide an overview of the most recent applications of these materials (mostly polymeric materials) in sample preparation for extraction purposes, as well as to provide a general vision of the current state-of-the-art of this field, their potential use and future applications.J.G.S. would like to thank “Cabildo de Tenerife” for the Agustín de Betancourt contract at the Universidad de La Laguna. The support of the Spanish Ministry of Science and Innovation (project PGC2018-094503-B-C21) is granted. This article is also based upon work from the Sample Preparation Task Force and Network supported by the Division of Analytical Chemistry of the European Chemical Society.Peer reviewe

Chain-Shattering Polymers as Degradable Microdispersive Solid-Phase Extraction Sorbents

A chain-shattering polymer (CSP) has been proposed as a microdispersive solid-phase extraction (μdSPE) sorbent in a proof-of-concept study of degradable materials for analytical purposes. The responsive CSP was synthesized from 1,3,5-tris(bromomethyl)-2-nitrobenzene acting as the self-immolative trigger responsive unit and 2,6-naphthalenedicarboxylic acid as aromatic linker to enhance noncovalent aromatic interactions with the analytes. The CSP was characterized and applied as a μdSPE sorbent of a group of plasticizers, which were selected as model analytes, from different types of environmental water samples (tap, waste, and spring waters). Gas chromatography coupled to mass spectrometry detection was used for analyte determination. Mean recovery values were in the range of 80%–118% with RSD values below 22%. After the extraction, the polymer could be efficiently degraded by UV irradiation or by chemical reduction, recovering the aromatic linker. This work has proved the potential of CSPs as recyclable sorbents, paving the way to more environmentally benign analytical procedures.C.O.-Z. and D.S. would like to thank the Spanish Ministry of Universities for the FPU fellowship. M.D.P. would like to thank the ACIISI and the European Social Fund (ESF) Canary Islands Integrated Operational Program 2014-2020, Area 3 Priority Theme 74 (85%), for a predoctoral grant. J.G.-S. would like to thank the ACIISI for the Catalina Ruiz contract at the Universidad de La Laguna (85% cofinanced from European Social Fund). The authors would like to acknowledge the ACIISI (Project ProID2021010111) and Ministerio de Ciencia e Innovación (PGC2018-094503-B-C21) for financial support, as well as the General Research Services (SEGAI) of the Universidad de La Laguna for the surface characterization measurements.Peer reviewe