ВПЛИВ РОЗМІРУ ПОР ТА МОРФОЛОГІЇ МЕЗОПОРИСТОГО КРЕМНІЮ НА ВИВІЛЬНЕННЯ МЕТОПРОЛОЛУ ТАРТРАТУ

Purpose. Study pore size effect and morphology of mesoporous silica on metoprolol tartrate release.Methodology. A sample of hollow mesoporous silicon dioxide with amino-functional groups containing 12.7 wt. % metoprolol tartrate has been investigated as potential carriers for the controlled release of active substance. Studies of the release profiles of metoprolol tartrate were performed under the following conditions: dissolution medium was buffer solution with a pH of 7.4 (phosphate buffer); sampling time: from 0.5 h before 18 h. The metoprolol concentration in the liquid phase was evaluated by a UV-Vis spectrophotometer (Persee TU-190, Beijing, China) by use of quartz cuvettes with an optical path length of 1 cm at a maximum wavelength of 274 nm.Findings. In this work we have studied mesoporous silica as possible carrier to controlled release of metoprolol tartrate, a drug used in the treatment of some diseases of the cardiovascular system. The material for research was a sample of hollow mesoporous silicon dioxide with amino-functional groups 200–400 nm in size and 20–30 nm in shell thickness. A calibrated curve to determine the amount of metoprolol was constructed by determining the absorption dependence of the concentration of metoprolol in the range from 10 to 300 ppm. The same drug concentration was obtained as calculated from the drug release test formula, which concludes that the release of metoprolol is controlled.Originality. The controlled release of a sample of hollow spheres of mesoporous silicon dioxide filled with metoprolol tartrate was studied, which was synthesized by the School of Chemistry and Chemical Engineering, Qilu University of Technology, using a new technology, where hollow spheres of mesoporous silicon dioxide with amino groups were synthesized using CO2 gas bubbles as templates.Practical value. The metoprolol release amount could achieve a 50% release amounts within 1 hour and 90% within 5 hours, indicating that the synthesized mesoporous hollow sphere could achieve controlled drug release, and shows the potential of carriers with stimulus response and targeted therapy.

Passivated Porous Silicon Membranes and Their Application to Optical Biosensing

A robust fabrication method for stable mesoporous silicon membranes using standard microfabrication techniques is presented. The porous silicon membranes were passivated through the atomic layer deposition of different metal oxides, namely aluminium oxide Al2O3, hafnium oxide HfO2 and titanium oxide TiO2. The fabricated membranes were characterized in terms of morphology, optical properties and chemical properties. Stability tests and optical probing noise level determination were also performed. Preliminary results using an Al2O3 passivated membranes for a biosensing application are also presented for selective optical detection of Bacillus Cereus bacterial lysate. The biosensor was able to detect the bacterial lysate, with an initial bacteria concentration of 106 colony forming units per mL (CFU/mL), in less than 10 min.

Stabilization of porous silicon nanoparticles by PEGalization in water

Mesoporous silicon (mPSi) nanoparticles (NPs) are stabilized by polyethylene glycol (PEG) chains during mechanical grinding in a ball mill that is used to form mPSi-PEG-NPs. The structure, composition, and properties of the obtained samples are studied by means of the dynamic light scattering, scanning electron microscopy and Fourier-transform infrared spectroscopy. The proposed PEGalization procedure is an effective way of regulating the dissolution of mPSi-NPs in water and it is promising for potential application of mPSi-NPs in drug delivery.

Magnetically-Targeted Nanoparticle-Guided M2 Macrophage Polarization For Fracture Healing Promotion

Background: Macrophages are essential for fracture healing, acting mainly through remodeling of the extracellular matrix and promotion of angiogenesis. The role of macrophages in regulating osteogenic differentiation, particularly that of the M2 phenotype, is increasingly researched. Baicalein (BCL) had also been shown to have pro-fracture-healing effects.Results: In this study, we developed mesoporous silica and Fe3O4 composite-targeted nanoparticles loaded with BCL (BCL@MMSNPs-SS-CD-NW), that could be magnetically delivered to the fracture site. These induced macrophage recruitment in a targeted manner, polarizing them towards the M2 phenotype, and thereby inducing MSCs towards osteoblastic differentiation. The mesoporous silicon nanoparticles (MSNs) were prepared with surface sulfhydrylation and amination modification, and the mesoporous channels were blocked with β-cyclodextrin. The outer layer of the mesoporous silicon was added with an amantane-modified NW targeting peptide to obtain the targeted nano-system. After entering macrophages, BCL could be released from nanoparticles since the disulfide linker could be cleaved by intracellular glutathione (GSH) resulting in the removing of CD gatekeeper, which is a key element in the pro-bone-remodeling functions, such as anti-inflammation and induction of M2 macrophage polarization to facilitate osteogenic differentiation.Conclusions: This nano-system passively accumulated in the fracture site, promoting osteogenic differentiation activities, highlighting a potent therapeutic benefit with high biosafety.