Preparation of functionalized protein materials assisted by mechanochemistry

Lei Wang,Niclas Solin

doi:10.1007/s10853-018-2461-7

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.

Highlights

Mechanochemistry has been used since prehistoric times, and it continues to be important in both everyday life and industrial settings [1, 2]
By addition of luminescent dyes protein nanofibrils (PNFs) can be prepared suitable for applications related to light emission [25,26,27,28]; in addition, interesting nonlinear optical effects have been observed in dye-doped PNF systems [29]
The effect of PNF formation on dye photophysics is investigated by spectroscopic examination by absorption and luminescence spectroscopy, and product morphology is examined by SEM

Summary

Introduction

Mechanochemistry has been used since prehistoric times, and it continues to be important in both everyday life (e.g., in cooking procedures) and industrial settings [1, 2]. We investigate the suitability of HEWL as a protein matrix for dispersal of hydrophobic dyes 1–5 (Fig. 2); in addition, we investigate the use of a shaker mill for grinding operation as an alternative to hand grinding by mortar and pestle. This effect is readily apparent, as can be seen, b, where photographs are shown in different samples, dispersed in 25 mM HCl and obtained under different milling conditions (number of grinding balls being 1, 10, 20 and 30).

Results

Conclusion