Alginate derivative-functionalized silica nanoparticles: surface modification and characterization

Innovative biopolyelectrolytes-based technologies for wastewater treatment

Developing eco-friendly, cost-effective, and efficient methods for treating water pollutants has become paramount in recent years. Biopolyelectrolytes (BPEs), comprising natural polymers like chitosan, alginate, and cellulose, have emerged as versatile tools in this pursuit. This review offers a comprehensive exploration of the diverse roles of BPEs in combating water contamination, spanning coagulation-flocculation, adsorption, and filtration membrane techniques. With ionizable functional groups, BPEs exhibit promise in removing heavy metals, dyes, and various pollutants. Studies showcase the efficacy of chitosan, alginate, and pectin in achieving notable removal rates. BPEs efficiently adsorb heavy metal ions, dyes, and pesticides, leveraging robust adsorption capacity and exceptional mechanical properties. Furthermore, BPEs play a pivotal role in filtration membrane techniques, offering efficient separation systems with high removal rates and low energy consumption. Despite challenges related to production costs and property variability, their environmentally friendly, biodegradable, renewable, and recyclable nature positions BPEs as compelling candidates for sustainable water treatment technologies. This review delves deeper into BPEs' modification and integration with other materials; these natural polymers hold substantial promise in revolutionizing the landscape of water treatment technologies, offering eco-conscious solutions to address the pressing global issue of water pollution.

Nano-SiO2 reinforced alginate-chitosan-gelatin nanocomposite hydrogels with improved physicochemical properties and biological activity

Alginate (Alg) hydrogels possess desirable advantages for application in tissue engineering; however, they are limited by their weak mechanical properties, poor chronical stability in phosphate buffered saline, and absence of mammalian cell recognition sites, severely restricting their biomedical applications. To overcome these limitations, we integrated Alg hydrogels with nano-silica (SiO2) to produce nano-SiO2 reinforced Alg-chitosan-gelatin nanocomposite hydrogels (Alg/SiO2-CHI-GA NCH) for biomedical purposes, utilizing Chitosan (CHI) and gelatin (GA) in an alternate electrostatic adsorption. Specifically, we investigated the regulatory and promotional effects of the nano-SiO2 on the morphological structure, mechanical properties, thermal stability, rheological properties, swelling, biodegradability, biomineralization and cytocompatibility of the resultant Alg/SiO2-CHI-GA NCH. The experimental findings demonstrate that the constructed Alg/SiO2-CHI-GA NCH exhibited uniform morphology and a regular structure. Upon freeze-drying, the internal cross-sections of the NCH exhibited a honeycomb porous structure. Furthermore, the physicochemical properties and biological activities of the prepared Alg/SiO2-CHI-GA NCH were regulated to some extent by nano-SiO2 content. Notably, nano-SiO2 inclusion enhanced the attachment and viability of MG63 and MC3T3-E1 cells and induced three-dimensional cell growth in ALG/SiO2-CHI-GA NCH. Among the fabricated NCH, Alg/SiO2-CHI-GA NCH with 0.5% and 1.0% (w/v) nano-SiO2 exhibited significant proliferative activity, which is attributable to their high porosity and uniform cell adhesion. Furthermore, the alkaline phosphatase activity in the cells gradually increased with increasing of nano-SiO2 amount, indicating the favorable effect of nano-SiO2 on the osteogenic differentiation of MG63 and MC3T3-E1 cells. Our study findings provide a comprehensive foundation for the structural- and property-related limitations of Alg hydrogels in biomedicine, thereby expanding their potential applications in tissue engineering.

Alginate-modified mesoporous bioactive glass and its drug delivery, bioactivity, and osteogenic properties

Mesoporous bioactive glass (MBG) is widely used in bone tissue repairing and drug loading. However, burst release of drug and poor compatibility with other materials limited its application. It is an effective way to modify MBG with a polymer brush to improve the properties. Herein, an alginate-modified MBG was prepared, and then, the effects of ALG on the properties of MBG were investigated. The results demonstrate that ALG could improve the drug loading efficiency, prolong drug release times, and make orderly deposition of apatite on the surface of MBG. Furthermore, MBG@ALG significantly promoted the osteogenic differentiation of MC3T3-E1 cells, demonstrating that surface modification of MBG by ALG can improve its properties, which will further broaden the application of MBG in tissue engineering.