Antimicrobial, anticancer, and biofilm inhibition studies of highly reduced graphene oxide (HRG): In vitro and in silico analysis

Background: Bacterial infections and cancers may cause various acute or chronic diseases, which have become serious global health issues. This requires suitable alternatives involving novel and efficient materials to replace ineffective existing therapies. In this regard, graphene composites are being continuously explored for a variety of purposes, including biomedical applications, due to their remarkable properties.Methods: Herein, we explore, in-vitro, the different biological properties of highly reduced graphene oxide (HRG), including anti-cancer, anti-bacterial, and anti-biofilm properties. Furthermore, to analyze the interactions of graphene with proteins of microbes, in silico docking analysis was also carried out. To do this, HRG was prepared using graphene oxide as a precursor, which was further chemically reduced to obtain the final product. The as-prepared HRG was characterized using different types of microscopic and spectroscopic techniques.Results: The HRG revealed significant cytotoxic ability, using a dose-dependent anti-cell proliferation approach, which substantially killed human breast cancer cells (MCF-7) with IC50 of 29.51 ± 2.68 μg/mL. The HRG demonstrated efficient biological properties, i.e., even at low concentrations, HRG exhibited efficient anti-microbial properties against a variety of microorganisms. Among the different strains, Gram-positive bacteria, such as B. subtilis, MRSA, and S. aureus are more sensitive to HRG compared to Gram-negative bacteria. The bactericidal properties of HRG are almost similar to a commercially available effective antibiotic (ampicillin). To evaluate the efficacy of HRG against bacterial biofilms, Pseudomonas aeruginosa and MRSA were applied, and the results were compared with gentamycin and ampicillin, which are commonly applied standard antibiotics. Notably, HRG demonstrated high inhibition (94.23%) against P.aeruginosa, with lower MIC (50 μg/mL) and IC50 (26.53 μg/mL) values, whereas ampicillin and gentamicin showed similar inhibition (90.45% and 91.31% respectively) but much higher MIC and IC50 values.Conclusion: Therefore, these results reveal the excellent biopotential of HRG in different biomedical applications, including cancer therapy; antimicrobial activity, especially anti-biofilm activity; and other biomedicine-based therapies. Based on the molecular docking results of Binding energy, it is predicted that pelB protein and HRG would form the best stable docking complex, and high hydrogen and hydrophobic interactions between the pelB protein and HRG have been revealed. Therefore, we conclude that HRG could be used as an antibiofilm agent against P. aeruginosa infections

Comparative Catalytic Evaluation of Nano-ZrO x

This work reports the zirconia (ZrOx) nanoparticles doped MnCO3 catalysts prepared by facile and simple coprecipitation technique and the synthesis of zirconia-manganese carbonate [X% ZrOx–MnCO3] (where X% = 0–7%) catalyst which upon calcination at 400°C is converted to zirconia-manganese dioxide [1% ZrOx–MnO2] and when calcined at 500°C is converted to zirconia-manganic trioxide [1% ZrOx–Mn2O3]. A comparative catalytic study was performed to investigate the catalytic efficiency between carbonate and oxides for the selective oxidation of 1-phenylethanol by using molecular O2 as a clean oxidant. The influence of several parameters such as w/w% of ZrOx, reaction time, calcination temperature, catalyst amount, and reaction temperature has been thoroughly examined using oxidation of 1-phenylethanol as a model substrate. The 1% ZrOx–MnCO3 precalcined at 300°C exhibited the best catalytic efficiency. It was found that ZrOx nanoparticles also play an essential role in enhancing the effectiveness of the catalytic system for the aerobic oxidation of alcohols. Furthermore, the physical and chemical properties of synthesized catalysts were evaluated by microscopic and spectroscopic techniques. An extremely high specific activity of 40 mmol·g−1·h−1 with a 100% conversion of oxidation product and selectivity of >99% was achieved within extremely short reaction time (6 min)

Evaluation of Biological Activities of Chemically Synthesized Silver Nanoparticles

Silver nanoparticles were synthesized by the earlier reported methods. The synthesized nanoparticles were characterized using ultraviolet-visible spectrophotometry (UV/Vis), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray powder diffraction (XRD). The synthesized materials were also evaluated for their antibacterial activity against Gram positive and Gram negative bacterial strains. TEM micrograph showed the spherical morphology of AgNPs with size range of 40–60 nm. The synthesized nanoparticles showed a strong antimicrobial activity and their effect depends upon bacterial strain as AgNPs exhibited greater inhibition zone for Pseudomonas aeruginosa (19.1 mm) followed by Staphylococcus aureus (14.8 mm) and S. pyogenes (13.6 mm) while the least activity was observed for Salmonella typhi (12.5 mm) at concentration of 5 µg/disc. The minimum inhibitory concentration (MIC) of AgNPs against S. aureus was 2.5 µg/disc and less than 2.5 µg/disc for P. aeruginosa. These results suggested that AgNPs can be used as an effective antiseptic agent for infectious control in medical field

A-π-D-π-A-Based Small Molecules for OTFTs Containing Diketopyrrolopyrrole as Acceptor Units

A-π-D-π-A-based small molecules 6,6′-((thiophene-2,5-diylbis(ethyne-2,1-diyl))bis(thiophene-5,2-diyl))bis(2,5-bis(2-ethylhexyl)-3-(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione) (TDPP-T) and 6,6′-(((2,3-dihydrothieno[3,4-b][1,4]dioxine-5,7-diyl)bis(ethyne-2,1-diyl))bis(thiophene-5,2-diyl))bis(2,5-bis(2-ethylhexyl)-3-(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione) (TDPP-EDOT) have been designed and synthesized. The diketopyrrolopyrrole acts as an electron acceptor, while the thiophene or 3,4-ethylenedioxythiophene acts as an electron donor. The donor–acceptor groups are connected by an ethynyl bridge to further enhance the conjugation. The optoelectronics, electrochemical, and thermal properties have been investigated. Organic thin film transistor (OTFT) devices prepared from TDPP-T and TDPP-EDOT have shown p-type mobility. In as cast films, TDPP-T and TDPP-EDOT have shown a hole mobility of 5.44 × 10−6 cm2 V−1 s−1 and 4.13 × 10−6 cm2 V−1 s−1, respectively. The increase in the mobility of TDPP-T and TDPP-EDOT OTFT devices was observed after annealing at 150 °C, after which the mobilities were 3.11 × 10−4 cm2 V−1 s−1 and 2.63 × 10−4 cm2 V−1 s−1, respectively

Applying Learning Analytics for Designing Effective Pedagogy for Online Courses: Analysis and Recommendations

The countrywide lockdown since March 2020 due to COVID 19 pandemic has brought drastic changes in the Indian education system. Today, many higher education institutions offer online delivery as an alternative and/or addition to provide more flexibility to learners, specifically in the current COVID 19 Pandemic. The conventional teaching method to the technology-driven virtual mode of teaching provided opportunities with challenges to academic stakeholders. Now with the new session, discussions on the reopening of educational institutions are going on. Hence, it is time to review the learning that took place during this pandemic situation. Learners being confronted with such services come with different expectations of what that means to their learning paths and behaviors. Learning Analytics is a relatively new and innovative way of making learner behavior and performances explicit by analyzing significant learners' feedback data. In this study, we take the case of online courses offered by various educational institutions all over India, and the analysis encompasses the population of learners of the online courses during the COVID 19 Pandemic period. Primary data has been collected using Google form when journals, reports, and websites are secondary data collection sources. We classified the data into distinctive parts: the overall learning experience of this course, the fulfillment of the learners' objectives, the difficulty of the assignments, the quality of the material supplied, the difficulty level of the course, the quality of the live session, opinion about the virtual approach of teaching, opinion about the contribution of virtual academic programs on knowledge building, opinion about the impact of virtual mode of teaching on performance, and opinion about the causes affecting students’ performance in the virtual mode of learning. The analysis outcomes will guide the host institutions and other similar institutions to design their pedagogy for future online courses more effectively, influencing learner engagement and retention

Development of Cerium Oxide/Chitosan/Graphene Oxide Nanocomposite: An Investigation toward Its Biological Applications under In Vitro Conditions

A ternary nanocomposite was prepared using cerium oxide, chitosan, and graphene oxide (CeO2/CS/GO) using a simple and cost-effective wet chemical method. The physicochemical properties of the developed ternary nanocomposite were examined using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and ultraviolet-visible spectroscopy. Furthermore, the therapeutic behavior of the developed CeO2/CS/GO composite was assessed using anti-bacterial, anti-fungal, and anti-cancer assays. For Escherichia coli, Staphylococcus aureus, and Salmonella species, 750 µg/mL of the CeO2/CS/GO composite showed effective anti-bacterial activity, with a zone of inhibition of 9 mm. Additionally, the CeO2/CS/GO composite’s anti-fungal activity against Aspergillus niger was studied. The anti-cancer properties of different concentrations of the CeO2/CS/GO composite were assessed on MCF-7 cells, and 18.8% of cells were found to be viable at the maximum concentration of 1000 µg/mL CeO2/CS/GO and 46.37% at 125 µg/mL. The results of the hemolysis assay performed using human red blood cells and various concentrations of the CeO2/CS/GO composite indicated that the nanocomposite possesses biological properties. Overall, it can act as a therapeutic platform for breast cancer, bacterial and fungal infections

Qualitative assessment on cisplatin loaded CeO2/Au/GO hybrid as theranostics platform in HeLa cell lines

Nanomaterials have been increasingly popular in bioimaging and cancer therapy due to their unique characteristics to reachtarget-specific tumours. Due to this uniqueness, a drug delivery platform made of nanomaterials has been developed to deliver theanti-cancer drug to target sites. As the number of incidences of cancer increases, it is critical to provide a medication delivery platform for treating cancer as soon as possible. Also, nanosystems based on carbon have been widely used as a possible biomarker for cancer imaging and therapeutics. This research work primarily focuses on the development of a spherical-shaped porous CeO2/Au/GO hybrid nanocomposite to serve as a nanoplatform to treatcervical cancer. The stacked layer of graphene oxide (GO) was loaded with porous aminated cerium oxide nanoparticles (CeO2 NPs) and gold nanoparticles (Au NPs). X-ray Diffraction (XRD),Field Emission Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were used to investigate their physio-chemical properties and morphology. Furthermore, HeLa cells were interacted with the suggested porous Au/GO hybrid, CeO2/Au/GO hybrid nanosystem and cisplatin-loaded CeO2/Au/GO hybrid system (CeO2/Cis-Au/GO hybrid), under in-vitro conditions to assess the anti-cancer efficacy of the proposed nanoplatforms. In this study, the minimum concentration of Au/GO at which nearly 50% of the cells remain dead (IC50 concentration)is considered to be 62.5 µg/mL and 31.2 µg/mL for CeO2/Au/GO. Further, the cisplatin anticancer drug was chemically bonded with CeO2/Au/GO hybrid nanosystem for testing the apoptotic efficacy of cancer cells under in-vitro conditions. The IC50 value was 62.5 µg/mL which affirmed the anticancer property of the CeO2/Cis-Au/GO system with HeLa cells. According to the findings from the antiproliferative assay, CeO2/Au/GO nanoplatforms resulted in superior cytotoxicity effects on cervical cancer in comparison with CeO2/Cis-Au/GO and Au/GO nanoplatform. Lastly, the proposed CeO2/Au/GO hybrid nanosystem was subject to dual staining investigation using Acridine Orange/Ethidium Bromide (AO/EB) dyes for recording the morphological changes incurred and also to visualize live and dead cells using fluorescence spectroscopy. Based on these findings, the developed CeO2/Au/GO hybrid nanosystem can be taken to in vivo studies for the validation to act as a theranostic platform for cervical cancer

Eco-Friendly Preparation of Silver Nanoparticles and Their Antiproliferative and Apoptosis-Inducing Ability against Lung Cancer

In the present study, the anti-proliferative and apoptotic potential of Tabebuia roseo-alba in lung cancer was assessed. Silver nanoparticles (AgNPs) of T. roseo-alba were synthesized using an ethanolic extract and characterized by adopting various parameters. Herein, the eco-friendly, cost-effective, and green synthesis of AgNPs was evaluated using an ethanolic extract of T. roseo-alba. The as-synthesized AgNPs were then characterized using various characterization techniques, such as UV-visible spectroscopy (UV-vis), X-ray powder diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The AgNPs are crystalline, spherical, and highly stable AgNPs of varying sizes in the range of 5–20 nm. The anticancer activity of the ethanolic extract of T. roseo-alba and its AgNPs was determined using an MTT assay. The results indicated that, although both samples showed prominent anti-proliferative activity on lung cancer cell lines, the AgNPs of T. roseo-alba were found to be more potent than the ethanolic extract. Further, apoptosis induction ability was evaluated by FITC Annexin V and PI staining, the results of which demonstrated the efficiency of the ethanolic extract of T. roseo-alba and its AgNPs in causing oxidative stress and subsequent cellular death. This was subsequently further confirmed by measuring the mitochondrial membrane potential after staining the cells with JC1. The apoptotic mode of cell death was further confirmed by DNA fragmentation and caspase assays using Western blot analysis

Cerium Oxide/Graphene Oxide Hybrid: Synthesis, Characterization, and Evaluation of Anticancer Activity in a Breast Cancer Cell Line (MCF-7)

In the present study, we used a simple ultrasonic approach to develop a Cerium oxide/Graphene oxide hybrid (CeO2/GO hybrid) nanocomposite system. Particle size analysis, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) have been used to analyze the physio-chemical characteristics of the developed nanocomposite. The synthesized hybrid system has also been examined to assess its anticancer capability against MCF-7 cell lines and normal cell lines at different sample concentrations, pH values, and incubation intervals using an antiproliferative assay test. The test results demonstrate that as sample concentration rises, the apoptotic behavior of the CeO2/GO hybrid in the MCF-7 cell line also rises. The IC50 was 62.5 µg/mL after 72 h of incubation. Cytotoxicity of cisplatin bound CeO2/GO hybrid was also tested in MCF-7 cell lines. To identify apoptosis-associated alterations of cell membranes during the process of apoptosis, a dual acridine orange/ethidium bromide (AO/EB) fluorescence staining was carried out at three specified doses (i.e., 1000 µg/mL, 250 µg/mL, and 62.5 µg/mL of CeO2/GO hybrid). The color variations from both live (green) and dead (red) cells were examined using fluorescence microscopy under in vitro conditions. The quantitative analysis was performed using flow cytometry to identify the cell cycle at which the maximum number of MCF-7 cells had been destroyed as a result of interaction with the developed CeO2/GO hybrid (FACS study). According to the results of the FACS investigation, the majority of cancer cells were inhibited at the R3 (G2/M) phase. Therefore, the CeO2/GO hybrid has successfully showed enhanced anticancer efficacy against the MCF-7 cell line at the IC50 concentration. According to the current study, the CeO2/GO platform can be used as a therapeutic platform for breast cancer. The synergetic effects of the developed CeO2/GO hybrid with the MCF-7 cell line are presented

Modified Polyacrylic Acid-Zinc Composites: Synthesis, Characterization and Biological Activity

Polyacrylic acid (PAA) is an important industrial chemical, which has been extensively applied in various fields, including for several biomedical purposes. In this study, we report the synthesis and modification of this polymer with various phenol imides, such as succinimide, phthalimide and 1,8-naphthalimide. The as-synthesized derivatives were used to prepare polymer metal composites by the reaction with Zn+2. These composites were characterized by using various techniques, including NMR, FT-IR, TGA, SEM and DSC. The as-prepared PAA-based composites were further evaluated for their anti-microbial properties against various pathogens, which include both Gram-positive and Gram-negative bacteria and different fungal strains. The synthesized composites have displayed considerable biocidal properties, ranging from mild to moderate activities against different strains tested