Hybrid Amyloid–Chitin Nanofibrils for Magnetic and Catalytic Aerogels

Abstract

In the quest for a sustainable and circular economy, it is essential to explore environmentally friendly alternatives to traditional petroleum-based materials. A promising pathway toward this goal lies in the leveraging of biopolymers derived from food waste, such as proteins and polysaccharides, to develop advanced sustainable materials. Here, we design versatile hybrid materials by hybridizing amyloid nanofibrils derived by selfassembly of whey, a dairy byproduct, with chitin nanofibrils exfoliated from the two distinct allomorphs of α-chitin and βchitin, extracted from seafood waste. Various hydrogels and aerogels were developed via the hybridization and reassembly of these biopolymeric nanobuilding blocks, and they were further magnetized upon biomineralization with iron nanoparticles. The pH-phase diagram highlights the significant role of electrostatic interactions in gel formation, between positively charged amyloid fibrils and negatively charged chitin nanofibrils. Hybrid magnetic aerogels exhibit a ferromagnetic response characterized by a low coercivity (<50 Oe) and a high specific magnetization (>40 emu/g) at all temperatures, making them particularly suitable for superparamagnetic applications. Additionally, these aerogels exhibit a distinct magnetic transition, featuring a higher blocking temperature (200 K) compared to previously reported similar nanoparticles (160 K), indicating enhanced magnetic stability at elevated temperatures. Finally, we demonstrate the practical application of these hybrid magnetic materials as catalysts for carbon monoxide oxidation, showcasing their potential in environmental pollution control and highlighting their versatility as catalyst supports.

Injectable Chitosan Hydrogels Doped with 2D Peptide Nanosheet‐Drug Conjugates for Glutathione‐Responsive Sustained Drug Delivery

“…Hydrogels, as an emerging drug carrier, have shown extensive applications in cancer drug delivery. [35,36] They possess the capability of sustained drug release, enabling the maintenance of elevated drug concentrations within tumor tissues for an extended period. This promotes effective drug accumulation at the tumor site, reduces systemic side effects, and mitigates inflammatory reactions caused by repeated injection.…”