Dynamic light scattering biosensing based on analyte-induced inhibition of nanoparticle aggregation.

A new approach to direct quantitative detection of small molecules (haptens) by dynamic light scattering biosensing is presented. The proposed technique implements a homogeneous competitive immunoassay and is based on optical detection of specific inhibition of nanoparticle aggregation induced by the analyte in a sample. The technique performance was tested both in buffer and milk for detection of chloramphenicol - antibiotic relevant to food safety diagnostics. Good specificity, sensitivity (LOD in milk is 2.4 ng/ml), precision (4.0 ± 1.2%), ruggedness (8.3%), and 96% recovery in conjunction with a record wide dynamic range (3 orders of magnitude) of the nanosensing technique were demonstrated. Such characteristics complemented by the assay simplicity (no washing step) and a short assay time make the approach attractive for application as an analytical platform for point-of-care and field-oriented diagnostics. Graphical abstract.

Magnetometry based method for investigation of nanoparticle clearance from circulation in a liver perfusion model.

Nanoparticles (NPs) are among the most promising agents for advanced theranostics. However, their functioning in vivo is severely inhibited by the mononuclear phagocyte system (MPS), which rapidly removes all foreign entities from blood circulation. Little is known about the sequestration mechanisms and the ways to counteract them. New methods are highly demanded for investigation with high scrutiny of each aspect of NP clearance from blood. For example, while liver macrophages capture the majority of the administered particles, reliable investigation of this process in absence of other MPS components is hard to implement in vivo. Here, we demonstrate a novel method for real-time investigation hepatic uptake of NPs in an isolated perfused liver based on an extremely accurate magnetometric registration technique. The signal is obtained solely from the magnetic NPs without any 'background' from blood or tissues, which is a significant advantage over other techniques, e.g. optical ones. We illustrate the method capacity by investigation of behavior of different particles and show good correlation with in vivo studies. We also demonstrate notable suitability of the method for studying the NP clearance from the flow in the user-defined mediums, e.g. those containing specific serum components. Finally, the method was applied to reveal an interesting effect of short-term decrease of liver macrophage activity after the first interaction with small amounts of NPs. The developed perfusion model based on the high-performance magnetometry can be used for finding new mechanisms of NP sequestration and for development of novel 'stealth' nanoagents.

Synthesis of magnetic silica nanomarkers with controlled physicochemical properties.

Magnetic markers which can be detected with an extremely high sensitivity with the method of magnetic particle quantification (MPQ) were synthesized. Using a controlled Stober reaction, a set of magnetic silica markers of different sizes and zeta potentials was obtained. The use of a carboxymethyl dextran polymer to stabilize the magnetite particles during the synthesis made it possible to substantially reduce the detection limit of the obtained construct, which opens up new opportunities for creating effective diagnostic nanoagents.

[Use of autogenous fibroblasts of human oral mucosa for gum recession treatment].

Minimally invasive soft tissue augmentation is a challenging problem for dentists. Use of autogenous fibroblast of oral mucosa is a promising method. The paper represents the results of preclinical, clinical and laboratory studies on the use of autogenous oral mucosa fibroblasts (AOMF) for gum recession correction. The results confirm statistically significant gum thickness augmentation and gum recession decrease after three weekly AOMF injections. The effect lasted for at least 9 months.

[Stem cells technologies in the treatment of burns].

Effective treatment of bums is one of effective in present medicine. Using cellular technology is one of the perspective directions for restoration of the integrity of the skin after burn injury an overview of the commercial preparations, presented at the European and American markets, and technologies developed by leading institutions in Russia.