Background: Nanoparticles (NPs) have been emerging as potential players in modern medicine with clinical applications ranging from therapeutic purposes to antimicrobial agents. However, before applications in medical agents, some in vitro studies should be done to explore their biological responses. Aim: In this study, protein binding, anticancer and antibacterial activates of zero valent iron (ZVFe) were explored. Materials and methods: ZVFe nanoparticles were synthesized and fully characterized by X-ray diffraction, field-emission scanning electron microscope, and dynamic light scattering analyses. Afterward, the interaction of ZVFe NPs with human serum albumin (HSA) was examined using a range of techniques including intrinsic fluorescence, circular dichroism, and UV–visible spectroscopic methods. Molecular docking study was run to determine the kind of interaction between ZVFe NPs and HSA. The anticancer influence of ZVFe NPs on SH-SY5Y was examined by MTT and flow cytometry analysis, whereas human white blood cells were used as the control cell. Also, the antibacterial effect of ZVFe NPs was examined on Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), and Staphylococcus aureus (ATCC 25923).
Results: X-ray diffraction, transmission electron microscope, and dynamic light scattering analyses verified the synthesis of ZVFe NPs in a nano-sized diameter. Fluorescence spectroscopy analysis showed that ZVFe NPs spontaneously formed a complex with HSA through hydrogen bonds and van der Waals interactions. Also, circular dichroism spectroscopy study revealed that ZVFe NPs did not change the secondary structure of HSA. Moreover, UV–visible data presented that melting temperature (Tm) of HSA in the absence and presence of ZVFe NPs was almost identical. Molecular dynamic study also showed that ZVFe NP came into contact with polar residues on the surface of HSA molecule. Cellular assays showed that ZVFe NPs can induce cell mortality in a dose-dependent manner against SH-SY5Y cells, whereas these NPs did not trigger significant cell mortality against normal white bloods in the concentration range studied (1–100 µg/mL). Antibacterial assays showed a noteworthy inhibition on both bacterial strains. Conclusion: In conclusion, it was revealed that ZVFe NPs did not induce a substantial influence on the structure of protein and cytotoxicity against normal cell, whereas they derived significant anticancer and antibacterial effects.

Background: Berberine (BBR) is a plant alkaloid that possesses anti-inflammatory and anti-oxidant effects with low oral bioavailability. In this study, micelle formulation of BBR was investigated to improve therapeutic efficacy and examined its effect on the secretion of inflammatory cytokines in cerebral ischemia in the animal model.Material and methods: Nano formulation was prepared by thin-film hydration method, and characterized by particle size, zeta potential, morphology, encapsulation efficacy, and drug release in Simulated Gastric Fluid (SGF) and Simulated Intestine Fluid (SIF). Then, Wistar rats were pretreated with the drug (100 mg/kg) and nano-drug (25, 50, 75, 100 mg/kg) for 14 days. Then, on the fourteenth day, stroke induction was accomplished by Bilateral Common Carotid Artery Occlusion (BCCAO); after that, Tumor Necrosis Factor - Alpha (TNF-α), Interleukin – 1 Beta (IL-1ß), and Malondialdehyde (MDA) levels were measured in the supernatant of the whole brain, then the anti-inflammatory effect of BBR formulations was examined.Result and discussion: Micelles were successfully formed with appropriate characteristics and smaller sizes than 20 nm. The Poly Dispersity Index (PDI), zeta potential, encapsulation efficacy of micelles was 0.227, − 22 mV, 81%, respectively. Also, the stability of nano micelles was higher in SGF as compared to SIF. Our outcomes of TNF-a, IL-1B, and MDA evaluation show a significant ameliorating effect of the Berberine (BBR) and BBR-loaded micelles in pretreated groups.Conclusion: Our experimental data show that pretreated groups in different doses (nano BBR 100, 75, 50 mg/kg, and BBR 100 mg/kg) successfully showed decreased levels of the inflammatory factors in cerebral ischemia compared with the stroke group and pretreated group with nano BBR in the dose of 25 mg/kg. Nano BBR formulation with a lower dose can be a better candidate than conventional BBR formulation to reduce oxidative and inflammatory factors in cerebral ischemia. Therefore, BBR-loaded micelle formulation could be a promising protective agent on cerebral ischemia.

Interestingly pharmaceutical sciences are using nanoparticles (NPs) to design and develop nanomaterials-based drugs. However, up to recently, it has not been well realized that NPs themselves may impose risks to the biological systems. In this study, the interaction of silver nanoparticles (AgNPs) with tau protein and SH-SY5Y neuroblastoma cell line, as potential nervous system models, was examined with a range of techniques including intrinsic fluorescence spectroscopy, circular dichroism (CD) spectroscopy, 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and acridine orange/ethidium bromide (AO/EB) dual staining method. Fluorescence study showed that AgNPs with a diameter of around 10–20 nm spontaneously form a static complex with tau protein via hydrogen bonds and van der Waals interactions. CD experiment revealed that AgNPs did not change the random coil structure of tau protein. Moreover, AgNPs showed to induce SH-SY5Y neuroblastoma cell mortality through fragmentation of DNA which is a key feature of apoptosis. In conclusion, AgNPs may induce slight changes on the tau protein structure. Also, the concentration of AgNPs is the main factor which influences their cytotoxicity. Since, all adverse effects of NPs are not well detected, so probably additional more specific testing would be needed.

Introduction: The application of nanoparticles (NPs) in medicine and biology has received great interest due to their novel features. However, their adverse effects on the biological system are not well understood. Materials and methods: This study aims to evaluate the effect of cerium oxide nanoparticles (CNPs) on conformational changes of human hemoglobin (HHb) and lymphocytes by different spectroscopic (intrinsic and synchronous fluorescence spectroscopy and far and near circular dichroism [CD] spectroscopy), docking and cellular (MTT and flow cytometry) investigations. Results and discussion: Transmission electron microscopy (TEM) showed that CNP diameter is ~30 nm. The infrared spectrum demonstrated a strong band around 783 cm⁻¹ corresponding to the CNP stretching bond. Fluorescence data revealed that the CNP is able to quench the intrinsic fluorescence of HHb through both dynamic and static quenching mechanisms. The binding constant (K_b), number of binding sites (n), and thermodynamic parameters over three different temperatures indicated that hydrophobic interactions might play a considerable role in the interaction of CNPs with HHb. Synchronous fluorescence spectroscopy indicated that microenvironmental changes around Trp and Tyr residues remain almost unchanged. CD studies displayed that the regular secondary structure of HHb had no significant changes; however, the quaternary structure of protein is subjected to marginal structural changes. Docking studies showed the larger CNP cluster is more oriented toward experimental data, compared with smaller counterparts. Cellular assays revealed that CNP, at high concentrations (>50 µg/mL), initiated an antiproliferative response through apoptosis induction on lymphocytes. Conclusion: The findings may exhibit that, although CNPs did not significantly perturb the native conformation of HHb, they can stimulate some cellular adverse effects at high concentrations that may limit the medicinal and biological application of CNPs. In other words, CNP application in biological systems should be done at low concentrations.