Nanoparticles exhibiting the localized surface plasmon resonance (LSPR) phenomenon are promising tools for diagnostics and cancer treatment. Among widely used metal nanoparticles, silver nanoparticles (Ag NPs) possess the strongest light scattering and surface plasmon strength. However, the therapeutic potential of Ag NPs has until now been underestimated. Here we show targeted photothermal therapy of solid tumors with 35 nm HER2-targeted Ag NPs, which were produced by the green synthesis using an aqueous extract of Lavandula angustifolia Mill. Light irradiation tests demonstrated effective hyperthermic properties of these NPs, namely heating by 10 °C in 10 min. To mediate targeted cancer therapy, Ag NPs were conjugated to the scaffold polypeptide, affibody Z_HER2:342, which recognizes a clinically relevant oncomarker HER2. The conjugation was mediated by the PEG linker to obtain Ag-PEG-HER2 nanoparticles. Flow cytometry tests showed that Ag-PEG-HER2 particles successfully bind to HER2-overexpressing cells with a specificity comparable to that of full-size anti-HER2 IgGs. A confocal microscopy study showed efficient internalization of Ag-PEG-HER2 into cells in less than 2 h of incubation. Cytotoxicity assays demonstrated effective cell death upon exposure to Ag-PEG-HER2 and irradiation, caused by the production of reactive oxygen species. Xenograft tumor therapy with Ag-PEG-HER2 particles in vivo resulted in full primary tumor regression and the prevention of metastatic spread. Thus, for the first time, we have shown that HER2-directed plasmonic Ag nanoparticles are effective sensitizers for targeted photothermal oncotherapy.

The extreme aggressiveness and lethality of many cancer types appeal to the problem of the development of new-generation treatment strategies based on smart materials with a mechanism of action that differs from standard treatment approaches. The targeted delivery of nanoparticles to specific cancer cell receptors is believed to be such a strategy; however, there are no targeted nano-drugs that have successfully completed clinical trials to date. To meet the challenge, we designed an alternative way to eliminate tumors in vivo. Here, we show for the first time that the targeting of lectin-equipped polymer nanoparticles to the glycosylation profile of cancer cells, followed by photodynamic therapy (PDT), is a promising strategy for the treatment of aggressive tumors. We synthesized polymer nanoparticles loaded with magnetite and a PDT agent, IR775 dye (mPLGA/IR775). The magnetite incorporation into the PLGA particle structure allows for the quantitative tracking of their accumulation in different organs and the performing of magnetic-assisted delivery, while IR775 makes fluorescent in vivo bioimaging as well as light-induced PDT possible, thus realizing the theranostics concept. To equip PLGA nanoparticles with targeting modality, the particles were conjugated with lectins of different origins, and the flow cytometry screening revealed that the most effective candidate for breast cancer cell labeling is ConA, a lectin from Canavalia ensiformis. In vivo experiments showed that after i.v. administration, mPLGA/IR775–ConA nanoparticles efficiently accumulated in the allograft tumors under the external magnetic field; produced a bright fluorescent signal for in vivo bioimaging; and led to 100% tumor growth inhibition after the single session of PDT, even for large solid tumors of more than 200 mm³ in BALB/c mice. The obtained results indicate that the mPLGA/IR775 nanostructure has great potential to become a highly effective oncotheranostic agent.

Respiratory pulmonary infections are a serious threat to human health. Their therapy is primarily based on the use of antibiotics. However, non-specific accumulation and low concentration in the target tissue reduce therapeutic effectiveness, cause side effects, and promote the development of antibiotic resistance. In this study, metal-organic frameworks (MOFs) with MIL-101 (Cr) structure were used for delivery of rifampicin to the lungs. The nanoparticles showed high antibiotic loading by mass, namely (127 ± 8) % for MIL-101 (Cr) and (82 ± 7) % for amino-modified NH2-MIL-101 (Cr). The kinetics of drug release had rapid and prolonged phases with up to 40 % of the loaded drug released in 7 h. It induces a significant inhibition of bacterial viability at a concentration of nanoparticles as low as 1 mg/L. After intravenous administration, the particles showed high tropism for lung accumulation reaching concentration of almost 300 %/g of tissue, more than 10 times higher than concentrations in other tissues. This study demonstrates the effectiveness of using MIL-101 (Cr) MOFs for pulmonary drug delivery and holds significant promise for developing antibacterial therapies.

Targeting HER2-positive cancer cells with precision therapies is a critical challenge in oncology. Here, we present a study on gold nanoparticles (AuNPs) conjugated with DARPin_9-29, a designed ankyrin repeat protein with high specificity and affinity for HER2 receptors. In this study, we investigate the therapeutic potential of AuNP-DARPin_9-29 conjugates, which was synthesized and characterized by us earlier, for photothermal therapy (PTT). By combining AuNP-DARPin treatment with visible light illumination, we show selective inhibition of HER2-positive cancer cell proliferation and tumor progression in a murine model. The results highlight the effectiveness of AuNP-DARPin in disrupting cancer cell viability and reducing tumor growth, providing a cost-effective and targeted approach for combating HER2-positive cancers.