Albumin binding, antioxidant and antibacterial effects of cerium oxide nanoparticles

Herein, the interaction of CeO2 NPs with HSA was explored by fluorescence, CD, UVevis and molecular docking studies. Afterwards, the antioxidant activity of CeO2 NPs against H2O2-induced oxidative stress in BM-MSCs were explored by MTT, ROS and apoptosis assays. Antibacterial assay was also done on two Gram-positive and Gram-negative bacterial strains. Fluorescence study showed that the interaction of CeO2 NPs with HSA occurs through static quenching and hydrophilic interactions are involved in the spontaneous complex formation. The theoretical study also revealed that the distribution of hydrophilic residues of HSA is dominant in the binding site. CD and UVevis techniques also revealed that the ellipticity changes and Tm of HSA, respectively did not alter significantly in the presence of CeO2 NPs. Cellular assays depicted that CeO2 NPs did not induce cytotoxicity against BM-MSC up to 50 mg/ml for 24 h and pretreatment of cells with CeO2 NPs can reduce the cell mortality, ROS production and apoptosis in BM-MSC exposed to oxidative stress. The antibacterial assay revealed that CeO2 NPs have a significant antibacterial effect against all studied bacterial strains. This study may provide useful details about the biomedical applications of CeO2 NPs

Silymarin-albumin nanoplex: preparation and its potential application as an antioxidant in nervous system in vitro and in vivo

In this study, we formulated silymarin-HSA nanoplex and assayed its ability to reduce LPSinduced toxicity in vitro and in vivo. Silymarin molecules were encapsulated into HSA nanoplex and the loading efficiency and characterization of fabricated nanoplex were performed by using HPLC, TEM, SEM, DLS, FTIR analysis, and theoretical studies. Afterwards, their protective effect against LPS (20 µg/ml) -induced toxicity in SH-SY5Y cells was investigated by MTT, ROS, and apoptosis assays. For in vivo experiments, rats were pre-treated with either silymarin or silymarin -HSA nanoplex (200 mg/kg) orally for 3 days and at third day received LPS by IP at a dose of 0.5 mg/kg, 150 min before scarification followed by SOD and CAT activity assay. The formulation of silymarin-HSA nanoplex showed a spherical shape with an average diameter between 50 nm to 150 nm, hydrodynamic radius of 188.3 nm, zeta potential of -26.6 mV, and a drug loading of 97.3%. In LPS-treated cells, pretreatments with silymarin-HSA noncomplex recovered the cell viability and decreased the ROS level and corresponding apoptosis more significantly than free silymarin. In rats, it was also depicted that, silymarin-HSA noncomplex can increase the SOD and CAT activity in brain tissue at LPS-triggered oxidative stress model more significantly than free counterpart. Nanoformulation of silymarin improved its capability to reduce LPS-induced oxidative stress by restoring cell viability and elevation of SOD and CAT activity in vitro and in vivo, respectively. Therefore, formulation of silymarin may hold a great promise in the field of antioxidant agent development

Gold nanozyme: Biosensing and therapeutic activities

The utilization of AuNPs in therapeutic applications has been accelerated by discovering their catalytic activity consistent with the activity of natural enzymes. However, to reduce unwanted activities, it is imperative to fully understand their catalytic mechanisms to increase efficiency and safety. Therefore, along with other reports, we aimed to classify the enzymatic activity of Au nanozymes based on recent advance in their applications in biosensing and therapeutic activities. The results of the reported experiments indicate that the Au nanozymes can be used in biosensing of a wide range of agents such as molecule (H2O2 and glucose), ions, nucleic acids, proteins, cells, and pathogens. Furthermore, they can be used as potential candidates in inhibition of neurodegenerative diseases, cancer therapy, and antibacterial activities. Biosensing and therapeutic activities are generally based on colorimetric assays and the controlling the ROS level in the targeted cells, respectively. Finally, a brief explanation of the current challenges of the Au nanozymes in biomedical approaches was discussed. Indeed, this review holds a great promise in understanding the Au nanozymes properties and their development in biotechnology, medicine, and related industries.Scopu

Antioxidant properties of gold nanozyme: A review

AuNPs with enzyme-like features have received strong attention in different areas, although limited data is available in literature on their biological/industrial functions. NPs especially Au counterparts have been shown to functionally mimic the activity of antioxidant enzyme. Indeed, due to low cytotoxicity and SPR characteristics of AuNPs, there are a great number of reports in which Au nanozymes yield promising responses in biomedical applications. In this review, we aim to overview the enzymatic activity of Au nanozymes along with their regulatory and controlling mechanisms. We have reviewed the effect of various factors such as dimension, morphology, functionalization and presence of hybrid materials on the catalytic activity of Au nanozymes as well as a detail survey on the oxidase, peroxidase, SOD, and CAT-like activities of Au nanozyme. Finally, the significance of Au nanozymes in mitigating oxidative stress followed by conclusion and challenges were reported. Based on this paper, we envision that Au nanozymes can be used as a promising material to prevent oxidative stress-stimulated disorders.Scopu

The effects of nickel oxide nanoparticles on structural changes, heme degradation, aggregation of hemoglobin and expression of apoptotic genes in lymphocytes

Nickel oxide nanoparticles (NiO NPs) have received great interests in medical and biotechnological applications. However, their adverse impacts against biological systems have not been well-explored. Herein, the influence of NiO NPs on structural changes, heme degradation and aggregation of hemoglobin (Hb) was evaluated by UV-visible (Vis) spectroscopy, circular dichroism (CD) spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM), and molecular modeling investigations. Also, the morphological changes and expression of Bax/Bcl-2 mRNA in human lymphocyte cell exposed to NiO NPs were assayed by DAPI staining and quantitative real-time PCR (qPCR), respectively. The UV-Vis study depicted that NiO NPs resulted in the displacement of aromatic residues and heme groups and production of the pro-aggregatory species. Intrinsic and Thioflavin T (ThT) fluorescence studies revealed that NiO NPs resulted in heme degradation and amorphous aggregation of Hb, respectively, which the latter result was also confirmed by TEM study. Moreover, far UV-CD study depicted that NiO NPs lead to substantial secondary structural changes of Hb. Furthermore, near UV-CD displayed that NiO NPs cause quaternary conformational changes of Hb as well as heme displacement. Molecular modelling study also approved that NiO NPs resulted in structural alterations of Hb and heme deformation. Moreover, morphological and genotoxicity assays revealed that the DNA fragmentation and expression ratio of Bax/Bcl-2 mRNA increased in lymphocyte cells treated with NiO NPs for 24hr. In conclusion, this study indicates that NiO NPs may affect the biological media and their applications should be limited. Communicated by Ramaswamy H. Sarma.Scopu

Plasmonic and chiroplasmonic nanobiosensors based on gold nanoparticles

Development of optical nanobiosensors has emerged as one of the most important bioresearch areas of interest over the past decades especially in the modern innovations in the design and utilization of sensing platforms. The application of nanobiosensors has been accelerated with the introduction of plasmonic NPs, which overcome the most of the limitations in the case of conventional optical nanobiosensors. Since the plasmonic AuNPs-based nanobiosensors provide high potential achievements to develop promising platforms in fully integrated multiplex assays, some well-developed investigations are clearly required to improve the current technologies and integration of multiple signal inputs. Therefore, in this literature, we summarized the performance and achievements of optical nanobiosensors according to plasmonic rules of AuNPs, including SPR, LSPR, SERS and chiroptical phenomena. Also, we investigated the effects of the physicochemical properties of AuNPs such as size, shape, composition, and assembly on the plasmonic signal propagation in AuNPs-based nanobiosensors. Moreover, we presented an overview on the current state of plasmonic AuNPs-based nanobiosensors in the biomedical activities. Besides, this paper looks at the current and future challenges and opportunities of ongoing efforts to achieve the potential applications of AuNPs-based optical plasmonic nanobiosensors in integration with other nanomaterials. Taken together, the main focus of this paper is to provide some applicable information to develop current methodologies in fabrication of potential AuNPs-based nanobiosensors for detection of a wide range of analytes.Scopu