The use of nanometal oxides in nanoagronomy has garnered considerable attention due to their excellent antifungal and plant growth promotion properties. Hybrid nanometal oxides, which combine the strengths of individual nanomaterials, have emerged as a promising class of materials. In this study, nanomagnesium oxide (n-MgO) and hybrid magnetic nanomagnesium oxide (m/n-MgO) were successfully synthesized via the ultrasound-mediated sol-gel method. Characterization results, including TGA, XRD, VSM, and FTIR, confirmed the successful synthesis of m/n-MgO. Both n-MgO and m/n-MgO underwent antifungal assays and plant growth promotion ability studies, benchmarked against the conventional fungicide-copper oxychloride. This study bridges a significant gap by simultaneously reporting the antifungal properties of both n-MgO and m/n-MgO and their impact on plant growth. The disc diffusion assay suggested that the antifungal activity of n-MgO and m/n-MgO against F. oxysporum was inversely related to the particle size. Notably, n-MgO exhibited superior antifungal performance (lower minimum inhibitory concentration (MIC)) and sustained efficacy compared with m/n-MgO, owing to distinct antifungal mechanisms. Nanorod-shaped MgO, with a smaller size (8.24 ± 5.61 nm) and higher aspect ratio, allowed them to penetrate the fungal cell wall and cause intercellular damage. In contrast, cubical m/n-MgO, with a larger size (20.95 ± 9.99 nm) and lower aspect ratio, accumulate on the fungal cell wall surface, disrupting the wall integrity, albeit less effectively against F. oxysporum. Moreover, in plant growth promotion studies, m/n-MgO-treated samples exhibited a 15.7% stronger promotion effect compared to n-MgO at their respective MICs. In addition, both n-MgO and m/n-MgO outperformed copper oxychloride in terms of antifungal and plant growth promoting activities. Thus, m/n-MgO presents a promising alternative to conventional copper-based fungicides, offering dual functionality as a fungicide and plant growth promoter, while the study also delves into the antifungal mechanisms at the intracellular level, enhancing its novelty.
Developing biomaterial scaffolds using tissue engineering with physical and chemical surface modification processes can improve the bioactivity and biocompatibility of the materials. The appropriate substrate and site for cell attachment are crucial in cell behavior and biological activities. Therefore, the study aims to develop a conventional electrospun nanofibrous biomaterial using reproducible surface topography, which offers beneficial effects on the cell activities of bone cells. The bioactive MgO/gC3N4 was incorporated on PAN/PEG and fabricated into a nanofibrous membrane using electrospinning. The nanocomposite uniformly distributed on the PAN/PEG nanofiber helps to increase the number of induced pores and reduce the hydrophobicity of PAN. The physiochemical characterization of prepared nanoparticles and nanofibers was carried out using FTIR, X-ray diffraction (XRD), thermogravimetry analysis (TGA), X-ray photoelectron spectroscopy (XPS), and water contact angle measurements. SEM and TEM analyses examined the nanofibrous morphology and the structure of MgO/gC3N4. In vitro studies such as on ALP activity demonstrated the membrane's ability to regenerate new bone and healing capacity. Furthermore, alizarin red staining showed the increasing ability of the cell-cell interaction and calcium content for tissue regeneration. The cytotoxicity of the prepared membrane was about 97.09% of live THP-1 cells on the surface of the MgO/gC3N4@PAN/PEG membrane evaluated using MTT dye staining. The soil burial degradation analysis exhibited that the maximum degradation occurs on the 45th day because of microbial activity. In vitro PBS degradation was observed on the 15th day after the bulk hydrolysis mechanism. Hence, on the basis of the study outcomes, we affirm that the MgO/gC3N4@PAN/PEG nanofibrous membrane can act as a potential bone regenerative substrate.
In recent times, magnesium oxide (MgO) nanoparticles are proven to be an excellent antibacterial agent which inhibits the growth of bacteria by generating reactive oxygen species (ROS). Release of ROS by nanoparticles will damage the cell membrane of bacteria and leads to the leakage of bacterial internal components and cell death. However, chemically synthesized MgO nanoparticles may possess toxic functional groups which may inhibit healthy human cells along with bacterial cells. Thus, the aim of the present study is to synthesize MgO nanoparticles using leaf extracts of Amaranthus tricolor and photo-irradiation of visible light as a catalyst, without addition of any chemicals. Optimization was performed using Box-Behnken design (BBD) to obtain the optimum condition required to synthesize smallest nanoparticles. The parameters such as time of reaction, the concentration of precursor, and light intensity have been identified to affect the size of biosynthesized nanoparticles and was optimized. The experiment performed with optimized conditions such as 0.001 M concentration of magnesium acetate as precursor, 5 cm distance of light (intensity), and 15 min of reaction time (light exposure) has led to the formation of 74.6 nm sized MgO nanoparticles. The antibacterial activities of MgO nanoparticles formed via photo-irradiation and conventional biosynthesis approach were investigated and compared. The lethal dosage of E. coli for photo-irradiated and conventional biosynthesis MgO nanoparticles was 0.6 ml and 0.4 ml, respectively. Likewise, the lethal dosage of S. aureus for both biosynthesis approaches was found to be 0.4 ml. The results revealed that the antibacterial activity of MgO nanoparticles from both biosynthesis approaches was similar. Thus, photo-irradiated MgO nanoparticles were beneficial over heat-mediated conventional method due to the reduced synthesis duration.