Large Mesoporous Silica Nanoparticles Research Articles

A novel oral biomimetic delivery system enhancing both the mucosal and systemic immunity of influenza virus vaccine

Oral vaccines hold great promise for preventing major infectious diseases, but their development is limited by various gastrointestinal tract (GIT) barriers and the low proportion of intestinal microfold (M) cells. Here, inspired by the specific absorption pathway of dietary fat, a novel bionic intestinal lymphatic delivery system based on large mesoporous silica nanoparticles (LMSN) was developed for oral delivery of H1N1 influenza split vaccine (SV). Encouragingly, LMSN with triglyceride biomimetic structure and encapsulated by double-end palmitic acid esterified PEG (PEG-DP), namely TGLMSN@PEG-DP, exhibited high intestinal epithelium permeability and excellent lymphatic targeting ability. Additionally, TGLMSN, which acting as both antigen carrier and adjuvant, significantly enhanced the ability of SV to stimulate dendritic cells maturation. The results demonstrated that TGLMSN@PEG-DP vigorously augmented SV-induced antigen-specific systemic and mucosal immunity, compared to oral SV alone. To our knowledge, this is the first study to customize mesoporous silica nanocarriers to load SV and deliver vaccines to mesenteric lymph nodes (MLNs) mainly through the intestinal epithelium cells (IECs) pathway rather than M cells route alone. This work will not only improve the existing influenza vaccination methods, but also open up a new avenue for the design of vaccines against pathogens infected via mucosal route.

Solid SiO2-Sealed Mesoporous Silica for Synergistically Combined Use of Inorganic and Organic Filters to Achieve Safe and Effective Skin Protection from All-Band UV Radiation.

To effectively shield the full band of ultraviolet (UV) radiation and provide desirable protection, the combination of inorganic and organic filters was often used to protect human skin from the serious harm of UV exposure. However, the incompatibility of different filters and their mutual negative effect limit the production of multifilter sunscreen. In addition, the hazard of reactive oxygen species (ROS) produced by inorganic filters after UV exposure and the skin permeability of organic filters remain unresolved problems. In this study, titanium dioxide (TiO2) and diethylamino hydroxybenzoyl hexyl benzoate (DHHB), two kinds of common filters with complementary UV shielding range, were first encapsulated into large mesoporous silica nanoparticles (MSN, ∼300 nm) to obtain MSN-TiO2 and MSN-DHHB. Also, a SiO2 coating was then made to seal and stabilize the MSN-TiO2 and MSN-DHHB. The structure, UV screen function, and safety of the SiO2-coated filters, MSN-TiO2@SiO2 and MSN-DHHB@SiO2, were evaluated. The good mechanical stability exhibited by the solid SiO2 layer prevented the release and skin penetration of the sealed DHHB and the photocatalysis of TiO2. Furthermore, the combination of MSN-TiO2@SiO2 and MSN-DHHB@SiO2 in sunscreen cream showed excellent UV shielding performance on covering the whole UV radiation range without mutual interference. Therefore, coating SiO2 over MSN is a feasible strategy for entrapping various filters to improve their photostability, preventing skin penetration and ROS generation, and enhancing their compatibility with different sunscreen formulations.

Design and implementation of fluorescence sensor based on all-inorganic perovskite quantum dots for rapid detection of tetracycline in water

All-inorganic perovskite quantum dots (IPQDs) have become the most popular materials in the field of fluorescence detection due to their excellent optical properties. However, it is still a challenge to implement IPQDs detection in the water environment. In this work, IPQDs stably existing in aqueous solution were successfully prepared and used as fluorophores, and large mesoporous silica nanoparticles (LMSNs) were used as support. A novel LMSNs@IPQDs fluorescence sensor was developed for the specific fluorescence detection of tetracycline (TC) in aqueous solution. The results showed that there was a good linear relationship between the fluorescence quenching degree of LMSNs@IPQDs and TC concentration in the range of 0.7–15 μM, and the detection limit was 93 nM. The fluorescence quenching mechanism was mainly the electron transfer between TC and IPQDs. At the same time, the LMSNs@IPQDs fluorescence sensor had better specific selectivity and anti-interference ability to TC. The method was applied to the determination of TC concentration in water environment and the recoveries were 94.7%–106.3%. This work has achieved a breakthrough of IPQDs in water detection and opened up a way for the application of IPQDs in fluorescence detection.