Preparation of MSNs@Keratin as pH/GSH dual responsive drug delivery system

Environmental stimulus-responsive mesoporous silica nanoparticles as anticancer drug delivery platforms

Currently, cancer poses a significant health challenge in the medical community. Traditional chemotherapeutic agents are often accompanied by toxic side effects and limited therapeutic efficacy, restricting their application and advancement in cancer treatment. Therefore, there is an urgent need for developing intelligent drug release systems. Mesoporous silica nanoparticles (MSNs) have many advantages, such as a large specific surface area, substantial pore volume and size, adjustable mesoporous material pore size, excellent biocompatibility, and thermodynamic stability, making them ideal carriers for drug delivery and release. Additionally, they have been widely used to develop novel anticancer drug carriers. Recently, MSNs have been employed to design responsive systems that react to the tumor microenvironment and external stimuli for controlled release of anticancer drugs. This includes factors within the intratumor environment, such as pH, temperature, enzymes, and glutathione as well as external tumor stimuli, such as light, magnetic field, and ultrasound, among others. In this review, we discuss the research progress on environmental stimulus-responsive MSNs in anticancer drug delivery systems, including internal and external environment single stimulus-responsive release and combined stimulus-responsive release. We also summarize the current challenges associated with environmental stimulus-responsive MSNs and elucidate future directions, providing a reference for the functionalization modification and practical application of these MSNs.

Synthesis and characterization of magnetic polymeric nanocomposites for pH-sensitive controlled release of methotrexate

As one of the well-known anticancer drugs, methotrexate (MTX) has been limited in clinical application due to its side effects on normal tissues. This study focused on the one-step hydrothermal synthesis and in vitro evaluation of Fe₃O₄/RGO-PEI as MTX carriers for targeted anticancer therapy. In which, the Fe₃O₄ provided magnetic response properties; RGO acted as a stage for Fe₃O₄ loading and improved the dispersion of Fe₃O₄; polyethylenimine (PEI) was used as a surface modifier and a storehouse for MTX. The prepared Fe₃O₄/RGO-PEI nanocomposites exhibited a suitable size, good stability and magnetic responsibility. And the MTX loading content and loading efficiency were calculated to be 26.6% and 90.5%, respectively. What's more, due to the diffusion and dissolution of PEI, the Fe₃O₄/RGO-PEI-MTX exhibited excellent pH-sensitivity, the values of MTX release rate (%) within 48 h at pH 5.8 and 4.0 were 64.3% and 87.4%, respectively. Furthermore, MTT assays in cancer cells (HepG2) and normal cells (HUVEC) demonstrated that Fe₃O₄/RGO-PEI-MTX exhibited high anticancer activity while low toxicity to normal cells, and also the Fe₃O₄/RGO-PEI composites were practically non-toxic. Thus, our results revealed that Fe₃O₄/RGO-PEI-MTX would be a competitive candidate for targeted delivery and controlled release of MTX.