Modulating nanostructures with polyvinylpyrrolidone: Design and development of a porous, biocompatible, and pH-Stable core-shell magnetic microrobot for demonstrating drug absorption from wastewater.

Increased antineoplastic drug concentrations in wastewater stem from ineffective treatment plants and increased usage. Although microrobots are promising for pollutant removal, they face hurdles in developing a superstructure with superior adsorption capabilities, biocompatibility, porosity, and pH stability. This study focused on adjusting the PVP concentration from 0.05 to 0.375 mM during synthesis to create a favorable CMOC structure for drug absorption. Lower PVP concentrations (0.05 mM) yielded a three-dimensional nanoflower structure of CaMoO4 and CuS nanostructures, whereas five-fold concentrations (0.25 mM) produced a porous structure with a dense CuS core encased in a transparent CaMoO4 shell. The magnetically movable and pH-stable COF@CMOC microrobot, achieved by attaching CMOC to cobalt ferrite (CoF) NPs, captured doxorubicin efficiently, with up to 57 % efficiency at 200 ng/mL concentration for 30 min, facilitated by electrostatic interaction, hydrogen bonding, and pore filling of DOX. The results demonstrated that DOX removal through magnetic motion showed superior performance, with an estimated improvement of 57% compared to stirring conditions (17 %). A prototype PDMS microchannel system was developed to study drug absorption and microrobot recovery. The CaMoO4 shell of the microrobots exhibited remarkable robustness, ensuring long-lasting functionality in harsh wastewater environments and improving biocompatibility while safeguarding the CuS core from degradation. Therefore, microrobots are a promising eco-friendly solution for drug extraction. These microrobots show promise for the selective removal of doxorubicin from contaminated wastewater.

A self-assembled three-dimensional hierarchical nanoflower: an efficient enzyme-mimetic material for cancer cell detection that improves ROS generation for therapy.

Three-dimensional (3D) nanomaterials with high functional properties are emerging as the most promising artificial enzymes for overcoming the significant disadvantages of natural enzymes. Anticancer therapy using 3D-enzyme mimetic materials has emerged as an essential development for catalyzing cancer cell destruction. We report for the first time a novel 3D-based enzyme mimetic material, CaMoO4/MoS2/CuS nanoflower (CMC NF), that exhibits a large specific surface area, uniform flower-like structure, excellent biocompatibility, and high porosity, making it a suitable candidate for cancer detection and therapy. Additionally, CMC NFs were conjugated with folic acid (FA) to selectively target cancer cells, resulting in FA-CMC NFs explicitly binding to overexpressed folate receptor alpha (FRα) in MDA-MB-231 cells. Based on the peroxidase activity, the FA-CMC NFs are an effective nanoprobe for the selective detection of MDA-MB-231 cells over a wide detection range (50 to 5.5 × 104 cells per mL) with a low limit of detection (LOD) value of 10 cells per mL. In addition to their cancer detection capability, the FA-CMC NFs also effectively generated ˙OH radicals in a concentration-dependent manner to treat cancer cells. Under light conditions, the FA-CMC NFs with H2O2 solution showed efficient degradation of methylene blue (MB) dye, and the solution color appeared to fade within 15 min, indicating that they generated ˙OH radicals, which can efficiently kill cancer cells. Thus, the superior functionality of FA-CMC NFs offers cost-effective, facile, and reliable cancer cell detection, providing a new treatment option for cancer treatment and diagnosis.