Enhancing Bioavailability of Fertilizer through an Amyloid-Like Protein Coating.

Foliar fertilization acts as a ubiquitous component of conventional crop production, which brings considerable economic and ecological costs. Due to droplets rebounding and splashing during spraying and rain erosion, low bioavailability of fertilizer results in severe environmental pollution. Contrary to conventional fertilizer formulations with polymers, surfactants, and organic reagents, a method of improving fertilizer bioavailability based on a biocompatible protein coating is presented herein. In this system, whey protein concentrate (WPC) can undergo amyloid-like aggregation after the reduction of its disulfide bond by the reducing agent tris(2-carboxyethyl) phosphine (TCEP). Such aggregation affords a fast formation of the optically transparent and colorless phase-transitioned WPC (PTW) coating at the solid/water interface, with robust interfacial adhesion stability. Upon packaging with fertilizers through electrostatic and hydrogen-bonding interactions, such reliable interfacial adhesion thereby facilitates the effective deposition of fertilizers on superhydrophobic and hydrophobic leaf surfaces, with excellent adhesion stability. Based on practical farmland test, this work demonstrates that the application of PTW can significantly boost the bioavailability of fertilizers and decrease at least 30% fertilizer use in large-scale crop planting. This innovative strategy has the great potential to offer a transformative step forward in managing fertilizer contamination and overuse in future agriculture.

Suppression of Sunscreen Leakage in Water by Amyloid-like Protein Aggregates.

A sunscreen offers indispensable skin protection against UV damage and related skin diseases. However, due to the poor interfacial stability of sunscreen coatings on the skin, the synthetic ingredients in sunscreen creams easily fall off and enter aquatic environments, causing large ecological hazards and skin protection failure. Herein, we tackle this issue by introducing amyloid-like protein aggregates into a sunscreen to noticeably enhance the interfacial robustness of sunscreen coatings on the skin. The synthesis of such an agent to suppress sunscreen leakage can be achieved by manipulating the phase transition of bovine serum albumin (BSA) in a mild aqueous solution at room temperature. The resulting phase-transitioned BSA (PTB) aggregates effectively entrap the sunscreen ingredients to generate a uniform cream coating on the skin with robust amyloid-mediated interfacial adhesion stability. With continuous flushing in aquatic environments, such as salt water and seawater, this PTB-modified sunscreen (PTB sunscreen) coated on the skin maintains a retention ratio as high as >92%, which is 2-10 times higher than those of commercially available sunscreen products. The high retention ratio of the PTB sunscreen in aquatic environments demonstrates the great potential of amyloid-like protein aggregates in the development of leakage-free sunscreens with low ecosystem hazards and long-lasting UV protection in aquatic environments.