Fabrication of fluorescent pH-responsive protein\u2013textile composites

Dalia Jane Saldanha,Noémie-Manuelle Dorval Courchesne,Zahra Abdali,Daniel Modafferi,Bita Janfeshan

doi:10.1038/s41598-020-70079-x

Dalia Jane Saldanha, Noémie-Manuelle Dorval Courchesne + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-70079-x

Copy DOI

Journal: Scientific Reports	Publication Date: Aug 3, 2020
Citations: 14	License type: open-access

Affiliation: McGill University

Abstract

Wearable pH sensors are useful tools in the healthcare and fitness industries, allowing consumers to access information related to their health in a convenient manner via the monitoring of body fluids. In this work, we tailored novel protein–textile composites to fluorescently respond to changing pH. To do so, we used amyloid curli fibers, a key component in the extracellular matrix of Escherichia coli, as genetic scaffold to fuse a pH-responsive fluorescent protein, pHuji. Engineered amyloids form macroscopic and environmentally resistant aggregates that we isolated to use as stand-alone hydrogel-based sensors, and that we trapped within textile matrices to create responsive bio-composites. We showed that these composites were mechanically robust and vapor-permeable, thus exhibiting favorable characteristics for wearable platforms. CsgA–pHuji fibers integrated in the textile allowed the final device to respond to pH changes and distinguish between alkaline and acidic solutions. We demonstrated that the resulting composites could sustain their fluorescence response over days, and that their sensing ability was reversible for at least 10 high/low pH cycles, highlighting their potential for continuous monitoring. Overall, we introduced a biosynthesized amyloid-based textile composite that could be used as biosensing patch for a variety of applications in the smart textile industry.

Highlights

Epidermal pH is an effective biomarker for preliminary detection of skin-related ailments such as dermatitis, acne and other bacterial and fungal infections[1]
To develop wearable diagnostic platforms from curli fibers, we first designed a protocol to fill the pores of textiles with protein materials, using wild type (WT) curli fibers as model proteins
Vacuum filtration had previously been used to isolate curli fiber hydrogels from bacterial cultures, with a protocol consisting of an incubation with a denaturing agent, guanidinium hydrochloride (GdmCl) to lyse bacterial cells; an incubation with benzonase nuclease to remove nucleic acids; and a final incubation in a surfactant, sodium dodecyl sulfate (SDS), to facilitate delamination and enhance gelation of the protein product; all of which were followed with water rinses[12,13]

Summary

Introduction

Epidermal pH is an effective biomarker for preliminary detection of skin-related ailments such as dermatitis, acne and other bacterial and fungal infections[1]. CsgA can be engineered to incorporate large and complex insertions at its C-terminal These insertions can be diverse in origin and application, including but not limited to, trefoil factors for gut healing, metal binding domains for surface adherence and fimbrial adhesins for vaccines against urinary tract infections[13,18,19,20]. These fusion proteins can self-assemble in bacterial growth media to form amyloid curli fibers that are innately resistant to harsh chemicals and proteases naturally present in sweat[21]. Rather than employing vacuum filtration to purify and isolate curli fibers from E. coli cells as previously described[12], we have utilized vacuum to force curli fibers into porous textiles and uniformly trap the fibers to form functional composites

Objectives

Methods

Results

Conclusion