This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Oxidative stress and abnormally high levels of reactive oxygen species (ROS) play an essential role in the pathogenesis and progression of inflammatory bowel disease (IBD). Oxidation‐responsive nanoparticles (NPs) are formulated from a phenylboronic esters‐modified dextran (OxiDEX) that degrades selectively in response to hydrogen peroxide (H2O2). OxiDEX NPs are coated with chitosan and encapsulated in a pH‐sensitive polymer to produce nano‐in‐micro composites. The microparticles are spherical with homogeneous particle size (53 ± 3 µm) and maintain integrity at acidic pH, preventing the premature release of the NPs in gastric conditions. The degradation of NPs is highly responsive to the level of H2O2, and the release of the drug is sustained in the presence of physiologically relevant H2O2 concentrations. The presence of chitosan on the particles surface significantly enhances NPs stability in intestinal pH and their adhesion on the intestinal mucosa. Compared to a traditional enteric formulation, this formulation shows tenfold decreased drug permeability across C2BBe1/HT29‐MTX cell monolayer, implying that lower amount of drug would be absorbed to the blood stream and, therefore, limiting the undesired systemic side effects. Based on these results, a successful nano‐in‐micro composite for targeted therapy of IBD is obtained by combination of the responsiveness to pH and ROS.
Mesoporous silica nanoparticles (MSNs) exhibit the typical characteristics of inorganic materials that make them promising drug delivery carriers for cancer therapy. Their structural properties allow the targeted delivery of chemotherapeutic drugs to enhance drug efficacy and reduce adverse effects. The functionalization of MSNs with targeting ligands to a specific tissue/cell and stimuli‐responsive capping materials to seal drugs inside the MSNs pores are widely studied for biomedical and pharmaceutical applications. Furthermore, multiple stimuli‐responsive MSN‐based drug delivery systems are developed to enhance the delivery of anticancer drugs to their specific target and thereby improve the release of the drugs at the intended site. In addition, several toxicity studies are conducted to evaluate the biosafety and biocompatibility of MSNs. Although MSNs present reduced toxicity compared to colloidal silica, they can induce cytotoxicity associated with oxidative stress by increased reactive oxygen species production and decreased glutathione levels that can ultimately lead to cell death. However, different modifications to control morphology and surface composition can be applied to overcome the biocompatibility concerns. In this review, a comprehensive overview of the controlled synthesis, functionalization, targeting and biocompatibility of MSNs, as well as their biomedical application as a chemotherapeutic delivery system is provided.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.