Evaluation of Ruthenium-Based Assemblies as Carriers of Photosensitizers to Treat Rheumatoid Arthritis by Photodynamic Therapy

For the first time, ruthenium-based assemblies have been used as carriers for photosensitizers in the treatment of rheumatoid arthritis by photodynamic therapy (PDT). These metallacages are totally soluble in physiological media and can transport photosensitizers (PS) in their cavity. After an incubation period, the PS is released in the cytoplasm and irradiation can take place. This strategy allows photosensitizers with low or null solubility in biological media to be evaluated as PDT agents in rheumatoid arthritis. The systems in which 21H,23H-porphine and 29H,31H-phthalocyanine are encapsulated show excellent photocytotoxicity and no toxicity in the dark. On the other hand, systems in which metalated derivatives such as Mg(II)-porphine and Zn(II)-phthalocyanine are used show good photocytotoxicity, but to a lesser extent than the previous two. Furthermore, the presence of Zn(II)-phthalocyanine significantly increases the toxicity of the system. Overall, fifteen different host–guest systems have been evaluated, and based on the results obtained, they show high potential for treating rheumatoid arthritis by PDT.

Les vésicules extracellulaires

Extracellular vesicles (EVs) originate from eukaryotic and prokaryotic cells and play a crucial role in intercellular communications. They are found in the environment of cells and tissues, and contribute to the complexity of different biological media, in particular biofluids. Due to their high diversity of cell origin, size range, concentration and composition, EVs offer some of the most important challenges in (pre-)analytical fields. To tackle these challenges, many works deal with the development and implementation of a wide variety of approaches, technologies and methodologies to enrich, isolate, quantify and characterize EVs and their subsets. Nevertheless, other components such as lipoproteins or viruses in complex samples, can interfere with EVs qualification, and make difficult, even today, to standardize biochemical and physical approaches for this purpose. The present chapter presents EVs and the mostly used technics for their isolation and characterization. Performances of methods in terms of resolution, discrimination, throughput and also ability to be or not applied in clinics, are also discussed.

Protein corona formation around biocatalytic nanomotors unveiled by STORM

The interaction of nanoparticles with biological media is a topic of general interest for drug delivery systems and among those for active nanoparticles, also called nanomotors. Herein, we report the use of super resolu-tion microscopy, in particular stochastic optical reconstruction microscopy (STORM), to characterize the formation of protein corona around active enzyme-powered nanomotors. First, we characterize the distribu-tion and number of enzymes on nano-sized particles and characterized their motion capabilities. Then, we incubated the nanomotors with fluorescently labelled serum proteins. Interestingly, we observed a signifi-cant decrease of protein corona formation (20 %) and different composition, which was studied by a proteo-mic analysis. Moreover, motion was not hindered, as nanomotors displayed an enhanced diffusion regardless of protein corona. Elucidating how active particles interact with biological media and maintain their self-propulsion after protein corona formation will pave the way of the use these systems in complex biological fluids in biomedicine.

PSVII-22 Changes in biochemical composition of saliva and blood of cattle after sunflower husk included in the diet

The aim of this study was to assess the effect of the introduction of food waste sunflower husk (SH) into the diet on the change in the chemical composition of biological media (blood and saliva) against the background of control (C). The studies were carried out on young 8-month cattle; ration of C - 70% roughage, 25% - concentrated feed, 5% - premix; SH - ration C + 10% sunflower husk (shredded, 0.5–2 mm), instead of the coarse part of the ration. The selection of biosubstrates (saliva, blood) was carried out in the morning before feeding: saliva was obtained by the method of local pharmacological stimulation of salivation (2% sodium citrate solution), blood from the jugular vein into vacuum tubes with a coagulation activator. The chemical composition of biological media was carried out on an automatic biochemical analyzer CS-T240 (Dirui Industrial Co., Ltd., China) using commercial biochemical kits for veterinary medicine (DIAKON-DS, Russia; Randox Laboratories Ltd, Great Britain). The inclusion of SH in the diet contributed to an increase in serum urea by 82.4% (P ≤ 0.05), lipase enzyme by 81.5% (P ≤ 0.05), uric acid by 62.7% (P ≤ 0.05), Ca and P by 73% and 21.8% (P ≤ 0.05), while a decrease in p-Amylase by 63.6% (P ≤ 0.05) and Fe by 86.8% (P ≤ 0.05) relative to C. After SH administration an increase in urea by 73% (P ≤ 0.05), digestive enzymes - lipase by 76.4% (P ≤ 0.05), p-amylase by 61 % (P ≤ 0.05), calcium by 69.3% and iron by 45% (P ≤ 0.05) and superoxide dismutase enzyme in comparison with C was registered in saliva. The obtained data show an increase in the level of digestive enzymes and elements in blood and saliva of ruminants, which favorably contributes to the use of sunflower husk in feeding cattle. This research was performed with financial support from the RSF (# 20-16-00088).

Gold Nanostars with Reduced Fouling Facilitate Small Molecule Detection in the Presence of Protein

Gold nanoparticles have the potential to be used in biomedical applications from diagnostics to drug delivery. However, interactions of gold nanoparticles with different biomolecules in the cellular environment result in the formation of a “protein corona”—a layer of protein formed around a nanoparticle, which induces changes in the properties of nanoparticles. In this work we developed methods to reproducibly synthesize spheroidal and star-shaped gold nanoparticles, and carried out a physico-chemical characterization of synthesized anionic gold nanospheroids and gold nanostars through transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential (ZP), nanoparticles tracking analysis (NTA), ultraviolet-visible (UV–Vis) spectroscopy and estimates of surface-enhanced Raman spectroscopy (SERS) signal enhancement ability. We analyzed how they interact with proteins after pre-incubation with bovine serum albumin (BSA) via UV–Vis, DLS, ZP, NTA, SERS, cryogenic TEM (cryo-TEM) and circular dichroism (CD) spectroscopy. The tests demonstrated that the protein adsorption on the particles’ surfaces was different for spheroidal and star shaped particles. In our experiments, star shaped particles limited the protein corona formation at SERS “hot spots”. This benefits the small-molecule sensing of nanostars in biological media. This work adds more understanding about protein corona formation on gold nanoparticles of different shapes in biological media, and therefore guides design of particles for studies in vitro and in vivo.