Synthesis of GO-Fe3O4-PANI nanocomposite with excellent NIR absorption property

Immobilization of L-Asparaginase on biofunctionalized magnetic graphene oxide nanocomposite: A promising approach for Enhanced Stability and reusability

The application of the amidohydrolase enzyme, L-asparaginase (ASNase), as a biocatalyst in the food and pharmaceutical industries has garnered significant interest. However, challenges such as hypersensitivity reactions, limited stability, and reusability under various operational conditions have hindered its cost-effective utilization. This paper introduces a novel nano-support for ASNase immobilization, namely the nanocomposite of iron oxide magnetic nanoparticles and amino acid-decorated graphene oxide (GO-Asp-Fe3O4). Characterization using FTIR spectroscopy, FE-SEM, and TEM microscopy revealed the homogeneous distribution of iron oxide nanoparticles on the surface of GO sheets. The effects of carrier functionalization and carrier-to-protein ratio on the immobilization of ASNase were studied to optimize the immobilization conditions. The magnetized nanocomposite of ASNase exhibited a 4.4-fold lower Michaelis-Menten constant (Km), suggesting an enhanced affinity for the substrate. The immobilized ASNase demonstrated two to eight times higher thermostability compared to the free enzyme and showed an extremely extended pH stability range. Furthermore, the immobilized enzyme retained over 80 % of its initial bioactivity after eight repeated reaction cycles. These findings suggest that the immobilization of ASNase on GO-Asp- Fe3O4 nanocomposite could be a viable option for industrial applications.

Loading polyaniline (PANI) nanoparticles to mesoporous hydroxyapatite (HAp) spheres for near infrared (NIR) induced doxorubicin (DOX) drug delivery and colon cancer treatment

In response to the pressing need for more efficient and targeted cancer therapies, this study presents the development of biodegradable hydroxyapatite/polyaniline (HAp/PANI) nanocomposite drug carriers for near-infrared (NIR)-induced drug delivery. The synthesis involved loading polyaniline onto mesoporous hydroxyapatite spheres, resulting in high drug loading capacity and tunable NIR responsiveness. The HAp/PANI spheres exhibited superior photothermal properties compared to pristine HAp under NIR irradiation, along with excellent biocompatibility. Importantly, the drug release behavior could be precisely controlled by adjusting NIR power and irradiation time, leading to enhanced anticancer efficacy against HCT-116 colorectal cancer cells. These findings highlight the potential of HAp/PANI mesoporous spheres as promising drug carriers for NIR-responsive cancer therapy.

IR780-doped cobalt ferrite nanoparticles@poly(ethylene glycol) microgels as dual-enzyme immobilized micro-systems: Preparations, photothermal-responsive dual-enzyme release, and highly efficient recycling

To solve the problems of separating dual enzymes from the carriers of dual-enzyme immobilized micro-systems and greatly increase the carriers' recycling times, photothermal-responsive micro-systems of IR780-doped cobalt ferrite nanoparticles@poly(ethylene glycol) microgels (CFNPs-IR780@MGs) are prepared. A novel two-step recycling strategy is proposed based on the CFNPs-IR780@MGs. First, the dual enzymes and the carriers are separated from the reaction system as a whole via magnetic separation. Second, the dual enzymes and the carriers are separated through photothermal-responsive dual-enzyme release so that the carriers can be reused. Results show that CFNPs-IR780@MGs is 281.4 ± 9.6 nm with a shell of 58.2 nm, and the low critical solution temperature is 42 °C, and the photothermal conversion efficiency increases from 14.04% to 58.41% by doping 1.6% of IR780 into the CFNPs-IR780 clusters. The dual-enzyme immobilized micro-systems and the carriers are recycled 12 and 72 times, respectively, and the enzyme activity remains above 70%. The micro-systems can realize whole recycling of the dual enzymes and carriers and further recycling of the carriers, thus providing a simple and convenient recycling method for dual-enzyme immobilized micro-systems. The findings reveal the micro-systems' important application potential in biological detection and industrial production.

Development of a novel three-dimensional magnetic polymer aerogel as an efficient adsorbent for malachite green removal

A novel three-dimensional (3D) magnetic bacterial cellulose nanofiber/graphene oxide polymer aerogel (MBCNF/GOPA) composed of bacterial cellulose nanofibers (BCNFs), Fe₃O₄ nanoparticles, graphene oxide (GO) nano-sheets, and polyvinyl alcohol (PVA) was developed by combining a facile filler-loaded networks method with a vacuum freeze-drying process for the removal of malachite green (MG) dye from aqueous solution. The influence of various factors on adsorption, including initial dye concentration, adsorbent dosage, contact time, temperature, and pH of dye solution, was then investigated. The adsorbent preserved a high adsorption capacity over a wide range of pH conditions. Moreover, the adsorption isotherms data fitted well with the Langmuir isotherm model with a maximum adsorption capacity of 270.27 mg g^-1. Adsorption kinetics followed the pseudo-second-order model, and the thermodynamic parameters showed that the adsorption of MG dye was feasible and endothermic in nature and occurred spontaneously. Therefore, owing to its demonstrated properties such as 3D interconnected porous structure, lightweight, large specific surface area, superparamagnetic behavior at room temperature, excellent adsorbent efficiency (93% removal) and also its simple and eco-friendly synthesis process, MBCNF/GOPA could be considered a promising candidate for removing cationic dye pollutants from aqueous solution, which can easily be collected from aqueous solution by a small magnet. MBCNF/GOPA also showed favorable reusability for MG removal in wastewater treatment, and its application in different water samples for the removal of MG dye molecules from "real" samples was successfully performed.