Recent advances in the field of biomaterials and an ever-growing need to curb the alarming rate of pollution levels have led to the utilization of biodegradable waste to fabricate sustainable materials with tunable properties. The current study investigated the growth kinetics and morphology of Pleurotus ostreatus (P. ostreatus) mycelium grown on different agricultural wastes such as wheat bran, sugarcane, sawdust, and the mixture of these substrates. Further, it delineated the fabrication process of biodegradable “bioblocks” from such agricultural waste using a green synthesis approach and mycelium P. ostreatus as a natural adhesive material. The fabricated bioblocks showed excellent thermal stability, hydrophobic properties, and mechanical strength. The compressive strength of these bioblocks was approximately 6.0–7.5 N/mm2, which is 5–6 times higher than that of the routinely used polystyrene packaging material. These properties of the bioblocks render them fit to replace the non-biodegradable materials that are commonly used in packaging applications, wall paneling, and filtration of toxic wastes.

We present the impact of surface modifications on the magnetic resonance imaging (MRI) contrast enhancement abilities of gadolinium oxide nanoparticles. A series of gadolinium oxide nanoparticles surface-coated with polyols of different reductive abilities such as diethylene glycol (DEG), triethylene glycol (TEG), tetraethylene glycol (TeEG), and polyethylene glycol (PEG 200) were synthesized. Particle sizes of synthesized Gd2O3 nanoparticles were found to be in correlation with the chain length of glycol. An enhancement in the in vitro and ex vivo relaxivity of Gd2O3 nanoparticles was revealed with the increase in glycol chain length. Among the various nanosystems, PEG-Gd2O3 has the highest in vitro and ex vivo relaxivities and excellent biocompatibility as revealed from cellular cytotoxicity experiments. The enhancement in MR contrast with glycol chain length can be attributed to the increase in surface hydrophilicity, and its modulation can be exploited as a novel strategy for enhancing the MRI contrast of gadolinium-based contrast agents.

Owing to the peculiar broad-spectrum antimicrobial activities of zinc oxide nanoparticles (ZnO NPs), we envisaged their use to treat bacterial/mycobacterial/fungal infections during peritoneal dialysis (PD) of end-stage renal failure patients. However, a recent study from our lab showed that ZnO-NPs cannot be employed for the same in their naked form owing to their rapid agglomeration. Also, the naked ZnO-NPs showed strong interaction with organic acids present in the PD fluid (i.e., lactate and citrate present abundantly in almost all biological fluids) resulting in the formation of bioconjugates. Here, we propose that the surface coating of ZnO NPs may inhibit the binding interactions of NPs with the constituents of PD fluid. Therefore, in this study, we have carried out the surface coating of ZnO NPs with polyethylene glycol (PEG) of different molecular weights, followed by the investigations of physicochemical properties of PEGylated ZnO NPs dispersed in PD fluid using nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) spectroscopy. The interaction of PEGylated ZnO NPs has also been studied separately in glucose and lactic acid which are the main constituents of PD fluid and in citric acid. Although the X-ray diffraction and TEM results infer the colloidal stability of PEGylated ZnO NPs in PD fluid, FT-IR, UV–vis, and nuclear magnetic resonance results revealed the binding interactions of PEGylated ZnO NPs with the PD constituents. PEGylated ZnO NPs also interact strongly with the lactic acid and citric acid, leading to agglomeration, as observed previously for uncoated ZnO NPs. Further, the antibacterial activities of bare and PEG-coated ZnO NPs dispersion in PD fluid have been studied. A reduction in the bacterial inhibition effect against Staphylococcus aureus and Escherichia coli was observed for both the bare and PEG-coated ZnO NPs dispersed in PD fluid, indicating that the complex nature of PD fluid counteract on the efficiency of these nanobiotics.

No abstract

Absence of effective antibiotics for the treatment of infectious peritonitis along with the appearance of multidrug-resistance has prompted the use of antimicrobial nanoparticles to impart infection resistant properties to the existing peritoneal dialysis (PD) fluid. To explore this research perspective, we investigated the solubility and physicochemical transformations of zinc oxide (ZnO) nanoparticles (NPs) dispersed in PD fluid using nuclear magnetic resonance spectroscopy in conjunction with dynamic light scattering, transmission electron microscopy, Fourier transform infrared and UV−visible spectroscopy. Our results emphasize that ZnO NPs strongly interact with organic acids found abundantly in biological fluids (demonstrated here with lactic and citric acid) and further lead to the formation of bioconjugates. On the basis of the current detailed investigations, we propose that the surface coating of ZnO NPs would be required to impart agglomeration resistant properties and to inhibit the binding interactions of NPs, thus rendering their safe and efficient intraperitoneal use as antimicrobials.