Present article provides a method of Bi@SiO2 core@shell nanocomposites obtaining via surface modification of laser-synthesized bismuth nanoparticles with t

Nanoparticles combining gold and iron oxide are promising for a wide range of biomedical applications, including photothermal therapy, radiotherapy enhancement, drug delivery, and diagnostic imaging. However, their long-term biodistribution and safety profile remain largely unexplored. Here, we synthesized Fe₃O₄@AuNP core–satellite nanoparticles (Fe₃O₄@AuNPs) using femtosecond laser ablation, functionalized them with 15 kDa polyethylene glycol (PEG), and characterized them using a panel of physicochemical techniques. Healthy C57BL/6 mice received an intravenous injection of Fe₃O₄@AuNPs at 730 mg Au/kg and 82 mg Fe/kg, respectively. Biodistribution was monitored by computed tomography (CT) and magnetic resonance imaging (MRI) over 12 months, after which gold and iron concentrations were measured ex vivo, and long-term toxicity was assessed via histology and blood biochemistry. Nanoparticles accumulated predominantly in the liver and spleen. Quantitative analysis of CT images revealed a gradual decrease in gold content, while MRI showed a progressive reduction in negative contrast in the liver between 6 and 12 months, suggesting possible changes in the Fe₃O₄ core structure. Over the one-year observation period, no differences in behavior or body weight gain were detected between the treated and control groups. Histological examination revealed no pathological changes other than mild age-related alterations. These findings provide a baseline for the long-term behavior of laser-ablated core–satellite Fe₃O₄@AuNPs, which is essential for their further development in diagnostic and theranostic 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 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.