Biology subjects

Ocwieja, M.

Publications and source records attributed to Ocwieja, M..

3 recordsLinked to original sources

bioRxiv2026

An Effective Metal Nanoparticle-Based Drug Delivery System for an In Vitro Model of Non Small Cell Lung Cancer

This study presents the development and spectroscopic characterization of an erlotinib-functionalized gold nanoparticle (erlotinib:AuNP) nanosystem designed for targeted delivery to metastatic non-small cell lung cancer H1299 cells. Initial MTS assays demonstrated that free erlotinib induced a concentration-dependent reduction in cell viability, while 0.1 {micro}M erlotinib exhibited negligible cytotoxicity and was therefore selected for nanosystem fabrication. AuNPs alone showed minimal toxicity toward H1299 cells over the investigated concentration range. Following conjugation of erlotinib with AuNPs, the resulting nanosystems reduced cell viability to approximately 60%, indicating enhanced biological activity of the drug after nanoparticle-assisted delivery. Fluorescence microscopy confirmed the intracellular internalization of the nanosystems in H1299 cells, with nanoparticle aggregates predominantly localized in the perinuclear and perimitochondrial regions. Three-dimensional Raman spectroscopy (3D RS) mapping further verified the intracellular localization of the conjugates through characteristic Raman signatures of erlotinib:AuNPs. Importantly, 3D RS enabled detection of nanosystems at concentrations below the sensitivity limit of fluorescence imaging, demonstrating superior analytical performance for intracellular nanosystem tracking. Atomic force microscopy-infrared (AFM-IR) spectroscopy coupled with principal component analysis (PCA) demonstrated substantial biochemical modifications induced by the erlotinib:AuNP nanosystems, including enhanced lipid-related spectral features and significant alterations in protein secondary structure, particularly the increased contribution of unordered and antiparallel {beta}-turn conformations. The obtained results demonstrate that combining plasmonic nanocarriers with advanced vibrational spectroscopy enables highly sensitive monitoring of intracellular drug delivery and nanosystem-induced biochemical responses in cancer cells.

biophysics↗

bioRxiv2026

Drug Affinity and Functionalization of Gold Nanoparticles: AFMSEIRA and SERS Study

This study presents the first investigation of the adsorption behaviour of Afatinib on gold nanoparticle (AuNP) monolayers, employing a combination of AFM-SEIRA and SERS techniques. Two types of AuNPs with distinct sizes, synthesized using different reagents, were employed to elucidate the influence of surface type on drug adsorption. The first type of AuNPs was synthesized using sodium borohydride (SB), whereas the second type was obtained using hydroxylamine hydrochloride (HH) as the reducing agent. AFM-SEIRA revealed that Afatinib interacts to the AuNPs primarily through the quinazoline ring, amide group, and amino moiety, with adsorption geometry strongly dependent on nanoparticle type. Contributions from CH3 and CH2 moieties were also identified, indicating their role in stabilizing the molecule/metal interface. Time-resolved SERS studies demonstrated that the adsorption process is dynamic and involves molecular reorientation, followed by gradual desorption, which is accelerated at physiological temperature (37 {degrees}C). Competitive adsorption experiments with phenylboronic acid (PBA) showed that Afatinib exhibits higher affinity toward AuNPs, however, co-adsorption leads to reduced stability of both species on the surface. The results reveal molecular insights into drug/nanoparticle interactions and emphasize the role of surface functionalization in efficient nanocarrier design. This work deepens understanding of adsorption at plasmonic interfaces for biomedical use.

biophysics↗

bioRxiv2022

Pathogens in exacerbations of chronic rhinosinusitis differ in sensitivity to silver nanoparticles

PurposeThe significance of the microbiome in chronic rhinosinusitis (CRS) is not clear. Antimicrobials are recommended in acute exacerbations of the disease (AECRS). Increasing rates of antibiotic resistance stimulate research on alternative therapeutic options including silver nanoparticles (AgNPs), sometimes referred to as "colloidal silver". However, there are concerns regarding the safety of silver administration and the emergence of silver resistance. The aim of this cross-sectional observational study was to assess the sensitivity of sinonasal pathogens to AgNPs and compare it with the toxicity of AgNPs for nasal epithelial cells. MethodsNegatively charged AgNPs (12{+/-}5 nm) were synthetized using tannic acid. The minimal inhibitory concentration (MIC) for pathogens isolated from patients with AECRS was approximated. Cytotoxicity of AgNPs was tested in vitro on human nasal epithelial cells line. Results48 clinical isolates and 4 reference strains were included in the study (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Acinetobacter baumanii, Serratia marcescens, Enterobacter cloacae). The MIC values differed between isolates, even within the same species. All the isolates (including antibiotic resistant) were sensitive to AgNPs in concentrations nontoxic to human cells during 24 h exposition. However, 48 h exposition to AgNPs increased toxicity to human cells, narrowing their therapeutic window and enabling 19% of pathogens to resist the AgNPs biocidal action. ConclusionsAgNPs are effective against most pathogens isolated from patients with AECRS, but sensitivity testing may be necessary before application. Results of sensitivity testing for reference strains cannot be extrapolated to other strains of the same species.

microbiology↗