We report the bactericidal effect of Ag and Cu NPs with different concentrations on methicillin-resistant S. aureus strain in comparison to the effect of AgNO₃ and CuCl₂ solutions, characterized by microbiological tests, TEM and Fourier-transform infrared spectroscopy. NPs were produced by nanosecond laser ablation in distilled water and characterized by scanning electron microscopy, UV-vis, energy dispersive X-ray, FT-IR spectroscopy, as well as X-ray diffraction, dynamic light scattering size and zeta-potential measurements. Microbiological tests showed antibacterial activity of NPs and metal ion-containing salts. Comparative FT-IR spectroscopy of bacteria, treated with metal NPs and salts, showed the broadening of amide I and II bands, a CH₂-related peak and its frequency decrease, indicating the increase of membrane fluidity. The main mechanisms of the antibacterial effect were proposed: Ag and Cu NPs release ions and ROS, which result in lipid peroxidation; AgNO₃ forms precipitates on the cell surface, which lead to the mechanical rupture of the membrane and subsequent possible penetration of the precipitates in the emerged damaged spots, complete destruction of the membrane and bacterial death; Cu ions from the CuCl₂ solution cause damage to phosphorus- and sulfur-containing biomolecules, which leads to disruption of intracellular biochemical processes. The theories were confirmed by FT-IR spectroscopy and TEM.

Boron Neutron Capture Therapy (BNCT) is one of the innovative methods for treating oncological diseases. Its selectivity is based on the targeted delivery of the boron-10 isotope to tumor cells, followed by neutron irradiation, the ¹⁰ B(n, α) ⁷ Li reaction occurs with a local release of 2.79 MeV of energy. Budding boron delivery agents are nanoscale systems. This study evaluated in vitro cytotoxicity, accumulation, and retention of elemental boron nanoparticles, synthesized by laser ablation and laser fragmentation, in U87 and BT474 tumor cells and BJ-5ta fibroblasts. It was shown that both types of nanoparticles exhibit low cytotoxicity at therapeutically relevant concentrations. Boron accumulation was maximal after 24 h of incubation and was significantly higher in tumor cells, especially in the BT474 cell line, compared to fibroblasts. The obtained data indicate the promise of these nanoparticles as boron delivery agents for BNCT.

Femtosecond laser-ablated gold nanoparticles (AuNPs) offer a unique platform for developing novel cost-effective contrast agents due to their ultraclean, surfactant-free synthesis and precisely tunable surface properties. This study developed three computed tomography (CT) contrast agents from a single stock solution of laser-ablated AuNPs, functionalized with polyethylene glycol (PEG-2kDa, PEG-4kDa), or lipoic acid with bovine serum albumin (BSA). The primary objective was to evaluate the safety and functional efficacy of these coated AuNPs in healthy and tumor-bearing mice. After a single intravenous injection (690 ± 30 mg Au/kg), all formulations were well tolerated with no acute toxicity observed. PEGylated AuNPs demonstrated long blood half-life (18 ± 2 h for PEG-2kDa; 37 ± 2 h for PEG-4kDa), making them suitable for cardiovascular imaging up to 24 h post-injection. BSA-AuNPs had a rapid blood clearance (T_1/2 = 2.8 ± 0.9 h), permitting cardiovascular assessment during the first 3 h, and provided intense, persistent contrast in abdominal organs, enabling liver imaging from 5 min and spleen imaging from 1 h post-injection. In a Ca755 mammary adenocarcinoma model, PEGylated AuNPs selectively accumulated in the tumor stroma and fibrous septa, allowing for precise tumor margin delineation and analysis of internal architecture. The findings establish that a single AuNP stock can be used to produce specialized contrast agents for specific imaging applications.

Femtosecond laser-ablated gold nanoparticles (AuNPs) offer a unique platform for developing novel cost-effective contrast agents due to their ultraclean, surfactant-free synthesis and precisely tunable surface properties. This study developed three computed tomography (CT) contrast agents from a single stock solution of laser-ablated AuNPs, functionalized with polyethylene glycol (PEG-2kDa, PEG-4kDa), or bovine serum albumin (BSA). The primary objective was to evaluate the safety and functional efficacy of these coated AuNPs in healthy and tumor-bearing mice. After a single intravenous injection (690±30 mg Au/kg), all formulations were well tolerated with no acute toxicity observed. PEGylated AuNPs demonstrated long blood half-life (18±2 h for PEG-2kDa; 37±2 h for PEG-4kDa), making them suitable for cardiovascular imaging up to 24 hours post-injection. BSA-AuNPs had a rapid blood clearance (T₁/₂=2.8±0.9 h), permitting cardiovascular assessment during the first 3 h, and provided intense, persistent contrast in abdominal organs, enabling liver imaging from 5 min and spleen imaging from 1 h post-injection. In a Ca755 mammary adenocarcinoma model, PEGylated AuNPs selectively accumulated in the tumor stroma and fibrous septa, allowing for precise tumor margin delineation and analysis of internal architecture. The findings establish that a single AuNP stock can be used to produce specialized contrast agents for specific imaging applications.

Antibacterial nanostructures were written on the surface of a silver (Ag) film and titanium (Ti) wafer using femtosecond laser ablation. The bactericidal properties were tested on S. aureus and P. aeruginosa bacterial strains. The resulting nanostructures were characterized by scanning electron microscopy (SEM). A flow-through filter, based on Ag plates with nanospikes, used as a sterilization of the liquid, led to the almost complete death of bacteria. It is assumed that the antibacterial properties are due to mechanical damage caused by the sharp nanoscale relief.