The production of non-toxic and homogeneous colloidal solutions of nanoparticles (NPs) for biomedical applications is of extreme importance nowadays. Among the various methods for generation of NPs, pulsed laser ablation in liquids (PLAL) has proven itself as a powerful and efficient tool in biomedical fields, allowing chemically pure silicon nanoparticles to be obtained. For example, laser-synthesized silicon nanoparticles (Si NPs) are widely used as contrast agents for bio visualization, as effective sensitizers of radiofrequency hyperthermia for cancer theranostics, in photodynamic therapy, as carriers of therapeutic radionuclides in nuclear nanomedicine, etc. Due to a number of complex and interrelated processes involved in the laser ablation phenomenon, however, the final characteristics of the resulting particles are difficult to control, and the obtained colloidal solutions frequently have broad and multimodal size distribution. Therefore, the subsequent fragmentation of the obtained NPs in the colloidal solutions due to pulsed laser irradiation can be utilized. The resulting NPs’ characteristics, however, depend on the parameters of laser irradiation as well as on the irradiated material and surrounding media properties. Thus, reliable knowledge of the mechanism of NP fragmentation is necessary for generation of a colloidal solution with NPs of predesigned properties. To investigate the mechanism of a laser-assisted NP fragmentation process, in this work, we perform a large-scale molecular dynamics (MD) modeling of FS laser interaction with colloidal solution of Si NPs. The obtained NPs are then characterized by their shape and morphological properties. The corresponding conclusion about the relative input of the properties of different laser-induced processes and materials to the mechanism of NP generation is drawn.

Cyclodextrin-functionalized micelles were studied using TEM, SAXS, and molecular dynamics simulations. Topography analysis showed clustering and low mobility of CDs, highlighting structural features important for optimizing nanoparticle drug delivery.

Targeted delivery of hydrophobic drugs is an urgent problem in pharmaceutics. These drugs are poorly soluble in water, which makes it difficult to transport them in the body and requires an increase in dosage, which can lead to side effects. Cyclodextrins can help solve this problem owing to their unique hydrophobic cavity, into which the drug can be embedded, and the hydrophilic outer surface, which ensures the solubility of such a complex in water. Lipid derivatives of cyclodextrins in an aqueous medium, owing to the hydrophobic interactions of lipid fragments, form micelle-like nanoparticles that are also soluble in water and capable of embedding hydrophobic molecules. Thus, the use of lipid derivatives of cyclodextrins in the process of creation of nanoparticles can improve the bioavailability and pharmacokinetic properties of drugs. In this study, the self-assembly of phospholipid conjugates with α-, β- and γ-cyclodextrins into nanoparticles is simulated by using the method of molecular dynamics produced using the GROMACS software package. As a result of calculations, models of micelle nanoparticles in the coarse-grained representation were obtained, the conformation of molecules in their composition was established, and the size of micelles was determined.

Synthetic glycolipids and similar amphiphils with peptide and other head groups have been designed for labeling/modification of living cells under mild physiological conditions. Under-standing the mechanism of their penetration through the cellular glycocalyx and subsequent insertion into the plasma membrane opens up the prospect of improving the recently found anti-tumor properties of such constructs. In this work, we applied small-angle X-ray scattering (SAXS) technique to characterize structure of nanoparticles formed by self-assembly of synthetic glycolipid A (type 2)-Ad-DE and to estimate its dependence on the glycolipid concentration. The studies were performed at a range of SAXS-applicable concentrations. The obtained results indicate that self-assembly process leads to formation of monodisperse nanoparticles with micelle-like architecture, which is maintained regardless of concentration, indicating absence of the nanoparticle’s positive interaction with their glycopart. We applied ab initio modeling that showed a good agreement with experimental data, and found that the ellipsoid monodisperse nanoparticles have a size of about 14 nm. Quasi-atomic modeling visualised that glycan ligands are well accessed for biological recognition. This knowledge will facilitate further study of the formation of the supramolecular form(s) of A(type 2)-Ad-DE and other glycolipids within the glycocalyx and its further fate in new therapeutic strategies.

Advances in nanotechnology in recent decades have spread to medicine and led to the emergence of nanotherapeutics that significantly increase the efficiency and reduce the side effects of drugs. One of the challenges in this field is increasing the solubility and targeted delivery of hydrophobic drugs. One approach to design nanoparticles for hydrophobic drugs loading is the use of cyclodextrins, which are capable of binding hydrophobic regions of small molecules via host-guest interactions. However, rational design of drug carriers requires studying the interactions between nanoparticles and drugs and assessing the effect of the bound drug on the surface properties of nanoparticles at the molecular level. In this work, we applied molecular dynamics simulations to study the interaction of core–shell micelles functionalized with alpha and beta CDs and a common drug, paclitaxel. Nanoparticle surfaces before and after interaction were analyzed using topographic mapping. It was found, that although paclitaxel molecules are able to partially penetrate into the cavities of both alpha and beta CD and form inclusion complexes, the fraction of molecules bound in this way is small, the majority of drug molecules ends up in cavities and grooves on the surface of the nanoparticles, the walls of which are lined with hydrophobic fragments of the spacer. In addition, paclitaxel molecules often cluster and adsorb on the surface of the hydrophobic core, but do not penetrate into it. The results obtained may be useful for the structure optimization and rational design of drug delivery systems.

We studied the process of self-assembly of these molecules at the atomic level. The formation of nanoparticles of phospholipid conjugates with α-, β-, and γ-cyclodextrins was modeled using the molecular dynamics method (GROMACS). Models of micelle nanoparticles were obtained, their conformation and size were determined.