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PurposeMesoporous silica (MS) have been considered as a biocompatible compound and found to have various pharmaceutical applications. Recently, novel approaches in applications of MS as antidote agents were introduced. In this study, the capacity of ethylenediaminetetraacetic acid modified mesoporous silica (MS-EDTA) was evaluated in in vitro and in vivo adsorption of copper (Cu).MethodsThe MS-EDTA was characterized by fourier transform infrared (FT-IR) and X-ray diffraction, while surface area was determined by N2 adsorption–desorption technique. Morphological studies were observed by high resolution-transmission electron microscopy and field emission-scanning electron microscopy and the sizes were determined by dynamic light scattering. The capacity of these particles for copper adsorption was investigated in vitro in both 1.2 and 7.2 pH. In in vivo animal study, the Cu adsorption efficiency of MS-EDTA in Cu-overdosed mice was evaluated. In this case, an animal model of acute copper poisoning was prepared.ResultsThe MS-EDTA with surface area of 352.35 was synthesized. Scanning electron microscope showed spherical particle formation with less than 500 nm in size. Transmission electron microscope images showed porous and honeycomb structure. FT-IR spectroscopy showed an appropriate formation of functional groups. Particle efficiency was investigated for Cu adsorption. MS-EDTA in both media showed a high adsorption capability for Cu (II) adsorption in pH=1.2 and pH=7.2. In addition, the study of Langmuir, Freundlich, and Redlich–Peterson adsorption models showed that copper adsorption by MS-EDTA followed the Freundlich model with multi-layer adsorption. In vivo evaluation showed that MS-EDTA could alleviate the symptoms of acute copper poisoning by lowering Cu plasma levels.ConclusionStructural evaluation showed successful formation of MS-EDTA. In vitro analysis demonstrated that supreme Cu adsorption occurs in both pH conditions (7.2 and 1.2), and was especially more favorable in simulated intestinal pH (7.2). The in vivo studies in animal models with acute Cu poisoning showed that MS-EDTA could be a potent antidote agent.

In this study, amino-functionalized mesoporous silica (MS) particles were synthesized and loaded with the anticancer drug, 5-Fu. In a post-modification reaction, the pores were gated by an azobenzene derivative to act as an enzyme-responsive drug delivery system. The synthesis and characterization of the MS structure were validated using various instrumental techniques such as XRD, N 2 adsorption/desorption, and FE-SEM and TEM. The loading efficiency and capacity of 5-Fu adsorption onto MS were evaluated; the adsorption isotherm graphs were plotted. The enzyme responsiveness feature of this nanocarrier was tested in the 5-Fu release study. The 5-Fu release from MS and the azo-capped compound was measured, and when sodium dithionite was used as a reducing agent and an azoreductase enzyme mimicker, the controlled release was observed. Finally, the cytotoxicity of 5-Fu loaded and azocapped MS in normal medium and sodium dithionate-containing medium was evaluated and compared with the cytotoxicity of the free drug.

The main barriers to cells or organ transplantation such as pancreatic β-cells are the need for lifelong immune suppression and the shortage of donors. It may be overcome via cell encapsulation and transplantation techniques. Hydrogels provide a suitable ECM-like microenvironment for cells to adhere, survive, and function, while weakly performing as an immune barrier. In this study, we aimed to macro-encapsulate islet cells in a dual encapsulation device with collagen hydrogel and PCL nanofiber to provide an immune-isolated environment for cells to function more efficiently, where immune cells are not allowed to enter but oxygen, insulin, and nutrients can pass through. PCL thin mats with the pores diameter of 500 nm were synthesized by electrospinning and characterized by scanning electron microscope, porosity measurement, tensile strength test, and contact angle measurement. Collagen hydrogel was fabricated by extracting collagen fibers from rat tail tendons and solving them in acetic acid. β-cells (CRI-D2 cell line) encapsulated after neutralizing collagen solution (pH ≈ 7.4). Cell-collagen gel complex was poured into the nanofibrous mat packets to fabricate the whole device. Histology evaluation, cell viability, and cell function tests were done in 10 days. Live/dead assay of Cri-D2 cells encapsulated within the device showed that cells have diffuse distribution at the core of the hydrogel and the device. Also, cluster formation was seen and shows these cells can live in groups. To identify cells’ function within the device in these 10 days samples’ supernatant insulin level was measured by chemiluminescent immunoassay. It just showed a positive result for existing insulin within the medium. Based on our results, this device presents adequate features to be a good immune-isolation device for cell transplanting.