Preparation of functionalized protein materials assisted by mechanochemistry

Abstract

Herein, we investigate the suitability of hen egg-white lysozyme (HEWL) as a protein matrix for dispersal of various hydrophobic dyes. Moreover, we investigate the use of a mixer mill for grinding operation as an alternative to hand grinding by mortar and pestle. HEWL and various dyes are mixed by mechanochemistry, and the resulting composite material is dissolved in aqueous acid. The samples are then exposed to conditions promoting self-assembly of HEWL into protein nanofibrils (PNFs). The effect of PNF formation on dye photophysics is investigated by spectroscopic examination by absorption and luminescence spectroscopy, and product morphology is examined by scanning electron microscopy. The self-assembly process results in protein nanofibrils functionalized with luminescent dyes. Such structures may find future applications in various devices for light emission. In addition, we demonstrate that the anticancer drug camptothecin can be incorporated into protein nanofibrils giving materials that can find application as drug delivery agents.

Mechanochemical Preparation and Self-Assembly of Protein:Dye Hybrids for White Luminescence

“…These results clearly indicate that lysozyme proteins milled with various dyes are still capable of forming LPNFs in agreement with previous studies. 45 …”

Protein nanofibrils and their use as building blocks of sustainable materials

“…PNFs have been functionalized with phosphorescent metal complexes, 197 as well as a laser dyes such as Nile red and DCM. 195,198,199 It should be noted that the presence of the hydrophobic material may dramatically perturb the self-assembly process, resulting in novel structures. However, by employing means such as agitation or stirring the reaction can be directed towards bril formation.…”

Air–Water Interface Assembly of Protein Nanofibrils Promoted by Hydrophobic Additives

“…This creates a practical mixing problem, as proteins typically are soluble in polar solvents where the solubility of many luminescent dyes is extremely low. We recently reported a method − where the drawback of low solubility is turned into an advantage: by utilizing a mechanochemical approach, where dry powders of the protein and the hydrophobic compound are mixed in the solid state by grinding, hybrid materials are obtained that can be dissolved/dispersed in aqueous media. The hybrid materials undergo self-assembly into PNFs incorporating the hydrophobic molecules that may provide extra functionality to the resulting material, including luminescence ,,, or magnetic properties …”