Hybrid porous silicon/green synthetized Ag microparticles as potential carries for Ag nanoparticles and drug delivery

High-load, sustained-release antibacterial composite particles based on modified vaterite coated with quaternary ammonium chitosan and aldehyde hyaluronic acid for controlled drug delivery systems

Porous vaterite particles exhibit good biocompatibility, degradability, and favorable physical and chemical properties, making them promising candidates for drug carriers. However, challenges such as low loading capacity, burst release effect and limited antibacterial properties hinder their practical applications. Herein, submicron vaterite particles were synthesized at low temperature and modified by stearic acid, and the resulting modified vaterite particles (Vc) possess exceptional loading capacity towards a typical anticancer drug - doxorubicin. Quaternary ammonium chitosan (QCS) with antibacterial properties was synthesized by chemically modifying chitosan and was coated onto the surface of Vc/Dox through electrostatic adsorption. Ag2CO3 nanoparticles were uniformly deposited on the surface of Vc/Dox/QCS through the reaction between Ag+ and CO32-, while a small amount of Ag nanoparticles was generated through the reduction of adsorbed Ag+, which was attributed to the reducing properties of -NH2 and aldehyde groups. Aldehyde functionalized hyaluronic acid was adsorbed on the outermost layer as a targeting polymer with the ability to induce cellular interaction. The composite (Vc/Dox/QCS/Ag/AHA) showed excellent sustained release and pH responsiveness, and the presence of QCS, Ag, and Ag2CO3 nanoparticles provided good antibacterial properties for the composite particles. In addition, cell experiments confirmed the almost no-cytotoxic properties and effective cellular interaction of the composite particles treated by low Ag+ concentration solutions. Compared with various micro-nanoparticles, this study ingeniously employed multifunctional polymers, Layer-by-Layer (LbL) technique, and modified inorganic nanoparticles to address the limitations of vaterite particles, paving the way for enhanced drug delivery applications and inspiring the development of multifunctional targeted drug capsules.

Plasmonic and Photothermal Effects of CuS Nanoparticles Biosynthesized from Acid Mine Drainage with Potential Drug Delivery Applications

In this work, the plasmonic and photothermal effects of CuS nanoparticles biosynthesized from acid mine drainage (AMD) were studied. CuS were formed by delivering the H2S generated by a sulfidogenic bioreactor to an off-line system containing the AMD. The precipitates collected after contact for an hour were washed and physico-chemically characterized, showing a nanoparticle with a mean diameter of 33 nm, crystalline nature and semiconductor behavior with a direct band gap of 2.2 eV. Moreover, the CuS nanoparticles exhibited localized surface plasmonic resonance in the near infrared range, with a high absorption band centered at 973 nm of wavelength, which allowed an increase in the temperature of the surrounding media under irradiation. Finally, the cytotoxicity of the CuS nanoparticles as well as their potential use as part of drug delivery platforms were investigated.

Change of Optical Properties of Carbon-Doped Silicon Nanostructures under the Influence of a Pulsed Electron Beam

In the work, porous silicon with observed photoluminescence was made from a p-type silicon substrate doped with boron and crystallographic orientation (100) using the method of electrochemical etching in a solution containing H2(SiF6) (silicon hydrofluoric acid) and ethyl alcohol. Thin carbon films were sprayed by high-frequency magnetron sputtering at room temperature onto the surface of porous silicon. The resulting carbon-doped thin films of porous silicon were irradiated on a pulsed electron booster and comparisons were made with nonirradiated films of porous silicon. To understand the effect of carbon on the properties of porous silicon films samples were analyzed by Raman spectroscopy, spectrophotometry, and scanning probe microscopy (SPM). The results of the SPM showed that the roughness of the samples increases after carbon doping on the surface of porous silicon. Thus, for the first time, experimental results were obtained on the effect of irradiation on carbon-doped porous silicon obtained in a solution containing hydrogen hexafluorosilicate H2(SiF6) and a significant change in its optical properties was shown. The results of the study showed that irradiated samples of carbon-doped porous silicon have better photoluminescence compared to nonirradiated samples.

Composite materials based on heteroaggregated particles: Fundamentals and applications

Homoaggregation of dispersed particles, i.e., aggregation of particles of the same shape, charge, size, and composition, is a well-studied field and various theoretical and experimental approaches exist to understand the major phenomena involved in such processes. Besides, heteroaggregation of particles, i.e., aggregation of particles of different shape, charge, size, or composition, has attracted widespread interest due to its relevance in various biomedical, industrial, and environmental systems. For instance, heteroaggregation of plastic contaminant particles with naturally occurring solid materials in waters (e.g., clays, silica and organic polymers) plays an important role in the decontamination technologies. Moreover, nanofabrication processes involving heteroaggregation of particles to prepare novel composite materials are widely implemented in fundamental science and in more applied disciplines. In such procedures, stable particle dispersions are mixed and the desired structure forms owing to the presence of interparticle forces of various origins, which can be tuned by performing appropriate surface functionalization as well as altering the experimental conditions. These composites are widely used in different fields from sensing through catalysis to biomedical delivery. The present review summarizes the recent progresses in the field including new findings regarding the basic principles in particle heteroaggregation, preparation strategies of heteroaggregated structures of different morphology, and the application of the obtained hybrid composites. Such information will be very helpful to those involved in the design of novel composites consisting of different nano or colloidal particles.

Inorganic-inorganic nanohybrids for drug delivery, imaging and photo-therapy: recent developments and future scope

Advanced nanotechnology has been emerging rapidly in terms of novel hybrid nanomaterials that have found various applications in day-to-day life for the betterment of the public. Specifically, gold, iron, silica, hydroxy apatite, and layered double hydroxide based nanohybrids have shown tremendous progress in biomedical applications, including bio-imaging, therapeutic delivery and photothermal/dynamic therapy. Moreover, recent progress in up-conversion nanohybrid materials is also notable because they have excellent NIR imaging capability along with therapeutic benefits which would be useful for treating deep-rooted tumor tissues. Our present review highlights recent developments in inorganic-inorganic nanohybrids, and their applications in bio-imaging, drug delivery, and photo-therapy. In addition, their future scope is also discussed in detail.