Endogenous NO-release multi-responsive hollow mesoporous silica nanoparticles for drug encapsulation and delivery

Construction and performance evaluation of pH-responsive oxidized hyaluronic acid hollow mesoporous silica nanoparticles

In this study, hollow mesoporous silica (HMSN) was created to facilitate drug distribution using the hard template method. The oxidized hyaluronic acid (oxiHA) was coated on the carrier surface by the Schiff base reaction, producing the pH-responsive nanoparticles HMSNs-DOX-oxiHA targeted by CD44 and preventing drug leakage from mesopores. The prepared nanoparticles had a size of 151.79 ± 13.52 nm and a surface potential of -8.42 ± 0.48 mV. The rich mesoporous structure and internal cavity of HMSNs-NH2 achieved the effective encapsulation and loading rates of doxorubicin (DOX) at 76.84 ± 0.24 % and 18.73 ± 0.05 %, respectively. Owing to the pH sensitivity of imine bonds, HMSNs-DOX-oxiHA has a good pH response and release performance. The in vitro experiments showed that the nanoparticles were not cytotoxic and could enhance HCT-116 uptake efficiency by hyaluronic acid/CD44 receptor-mediated endocytosis, effectively inhibiting tumor cell proliferation and reducing toxic side effects on normal cells. In summary, the polysaccharide-based nano-drug delivery system constructed in this experiment not only has the basic response properties of a carrier but also introduces the bioactive advantages of natural polysaccharides.

Ratiometric electrogenerated chemiluminescence sensing microRNA based on electrochemically controlled release of lucigenin from silica/chitosan/lucigenin nanoparticles

The dye-doped silica nanoparticles-based electrogenerated chemiluminescence (ECL) has been widely explored for analytical purposes due to its high sensitivity, simplicity and wide dynamic concentration range. However, only a few of dye molecules located at the near surface of nanoparticles can participate in the ECL reaction due to the poor conductivity of silica nano-matrix. In addition, the ECL signal is easy to be affected by environmental interference, which results in poor accuracy. Herein, a ratiometric ECL sensing method is established based on the electrochemically controlled release of lucigenin molecules from silica/chitosan/lucigenin composite nanoparticles (Lu/CS NPs) with the aid of sulfide ions. Firstly, H+ produced from the electrochemical oxidation of HS- ions can combine with SiO- and displace lucigenin from Lu/CS NPs. The released lucigenin molecules react with the reactive oxygen species (ROS) generated from the electroreduction of dissolved oxygen to produce the cathodic ECL signal. In addition, the excited elemental sulfur from the electrooxidation of HS- ions transfers its energy to lucigenin molecules and makes them be excited to produce energy-transfer anodic ECL signal. Based on these findings, a ratiometric ECL sensor is developed taking the anodic ECL intensity of lucigenin as a reference signal for the cathodic ECL of lucigenin. The proposed ratiometric ECL sensor has been successfully applied to the detection of let-7a with a wide linear range of 0.1-9.0 pM, a low detection limit of 28 fM, high selectivity and good reproducibility. Moreover, the developed approach was used to detect let-7a in human serum composite samples with good recoveries.

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.