Doga Kavaz

Silver nanoparticles were green-synthesized using Arbutus andrachne and Pistacia lentiscus leaf extracts and evaluated for antimicrobial, antioxidant, and anticancer activities. The study explores underexamined Cypriot plants as sources of bioactive nanomaterials.

A sustainable method has been developed to produce multi-walled carbon nanotubes (MWCNTs) that are adorned with a unique silver nanoparticle, using a plant extract (Origanum dubium) as a mediator. Gas chromatography/mass spectrometry (GC/MS) technique was used to investigate the chemical components of the plant extract. Silver nanoparticles (AgNPs) have been deposited on the MWCNTs as well as acid-functionalized MWCNTs (f-MWCNTs) via an in situ solution method. The present study presents a sustainable and economical approach to the synthesis of AgNPs. The biosynthesis of Ag nanoparticles has been optimized by varying several parameters, including pH, temperature, reaction time, concentration of plant extract, and duration of UV exposure. The nanohybrids composed of AgNPs, MWCNTs, acid-treated MWCNTs, and AgNP-decorated MWCNT nanocomposites were successfully synthesized and evaluated for their antibacterial potential against the Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and the Gram-negative Escherichia coli (E. coli) strains. Their radical scavenging activities were also evaluated against DPPH and hydrogen peroxide. X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FTIR), and UV–vis spectroscopy were used to investigate the structure and nature of f-MWCNT and decorated nanocomposites. The scanning electron microscopy (SEM) technique was used to analyze the dispersion state of carbon nanotubes and the immobilization of AgNPs. The study reveals that the modified AgNPs possess viable antimicrobial and antioxidant activities.

Background: Nanoparticles have been used in nanomedicine for therapeutic purposes. Lipids have been a popular choice of material in the synthesis of biocompatible nanoparticles due to their ability to encapsulate diverse therapeutic agents. However, once introduced into biological environments, nanoparticles rapidly adsorb proteins on their surface, forming a protein corona that can alter drug release, targeting and cellular interactions. Understanding these effects is essential for optimizing solid lipid nanoparticles (SLNs) as drug delivery systems. Methods: SLNs were synthesized using stearic acid (SA) as the lipid core and stabilized with surfactants, Tween 80 and SDS (sodium dodecyl sulphate). To mimic in vitro conditions, SLNs were incubated with 5% FBS (foetal bovine serum) for varying durations to allow soft and hard protein corona formation. SLNs were characterized for size and surface charge via dynamic light scattering while UV visible spectroscopy, protein adsorption studies, FTIR and the Bradford Assay were employed to confirm and quantify protein corona formation. In parallel, molecular docking was conducted to analyse protein-nanoparticle interactions. To investigate the potential influence of protein corona formation on drug release, ceftriaxone (CTX) was encapsulated within SLNs followed by immediate incubation to allow corona formation. Subsequent evaluations included drug leakage, release profile and antibacterial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa . Results: Protein adsorption was confirmed on all SLN formulations and closely correlated with nanoparticle surface charge. Formulations with more negative zeta potentials adsorbed higher amounts of protein. SDS concentration influenced protein adsorption with higher SDS content reducing overall corona formation. Molecular docking revealed that protein-ligand interactions were maintained by hydrogen bonding and hydrophobic forces. Drug release studies confirmed that the protein corona reduced cumulative drug release by 6%. Antibacterial assays confirmed slightly reduced efficacy against both strains aligning with the reduced cumulative drug release. Conclusions: This study demonstrated that protein corona formation on dual-surfactant SLNs is strongly influenced by surface charge and surfactant composition and in turn modulates drug release dynamics. The protein corona was shown to modulate drug release with potential implications for antibacterial efficacy. These findings highlight the importance of tailoring surface properties to control protein-nanoparticle interactions thus providing insight into the design of lipid-based nanoparticles for therapeutic applications.

Combining synthetic and natural polymers to increase stability, biocompatibility, and targeted drug delivery, lipid–polymer hybrid nanocapsules (LPHNCs) mark a development in cancer treatment. Notably, LPHNCs reduce long‐term toxicity through biodegradable components. In this study, nanocapsules (NCs) with doxorubicin (DOX) and paclitaxel (PTX) were developed to specifically target breast cancer cells with folate receptors. For in vitro targeting studies, the NCs were functionalized with fluorescein isothiocyanate (FITC) and folic acid (FA). This study discusses the differential characteristics of PTX inside the lipophilic matrix and DOX within the hydrophobic polymeric core to maximize bioavailability and therapeutic precision via the single encapsulation of PTX and DOX. The structural and chemical characteristics of the NCs were investigated via DLS, FTIR spectroscopy, XRD, PL spectroscopy, FESEM, and TEM. Moreover, the characteristics of encapsulation, release, and cytotoxicity were examined. The biological functioning was evaluated via MTT assays, revealing a concentration‐ and time‐dependent cytotoxic reaction. From 24 to 48 h, the IC ₅₀ values showed a twofold drop, suggesting a stronger pharmacodynamic effect. Both preparations remained biocompatible at sub‐cytotoxin levels (<20 µg/mL). These findings highlight the opportunities of LPHNCs as a flexible nanoplatform to optimize solubility, bioavailability, and controlled release for improved oncological usage.

Thymus capitatus (Th. Ca) is known to treat mouth ulcers and respiratory infections in Cyprus. However, antioxidant, antibacterial and cytotoxic potential of Th. Ca. EO on MDA-MB-231 cells and its' encapsulation into nanoparticles has not been well studied. Therefore, we aimed to analyse the antioxidant, antibacterial, cytotoxic potential, loading efficiency and in vitro release profile of both Th. Ca. EO and Chitosan Nanoparticle (Ch. Np) - Th. Ca. EO. GC-MS analysis revealed 53.97% carvacrol, 14.53% borneol and 12.09% sabinene presence in EO. The loading efficiency of Th. Ca. EO into Ch. Np. was calculated as 35.27% and the in vitro release profile reached a maximum of 68% in pH 7 for two weeks. The Minimum Inhibitory Concentration (MIC) assay showed that E. coli had an MIC₅₀ of 0.3215 mg/ml while B. subtilis had an MIC₅₀ of 0.5304 mg/ml. The antioxidant activity of the EO was assessed by performing a DPPH assay with an IC₅₀ = 440 μg/ml. Trypan Blue Assay revealed that 60 µg/ml Th. Ca. EO significantly reduced the cell viability of MDA-MB-231 cells by 10.7% at 48h and 20.06% at 72h. Overall, Ch. Np. - Th. Ca. EO has shown a promising formulation for the pharmaceutical industry.