(560g) Engineered Selective Biotoxin-Binding Hydrogels for Barrier Membranes

The design of materials that are able to mimic the behavior of nature without copying its mechanisms provides new avenues for materials development. Of need are membranes that can selectively transport specific components based on their interactions via characteristics other than overall size, charge, or polarity. Cholera, which is caused by infection in the gastrointestinal tract by the bacterium Vibrio cholerae, is a worldwide public health threat, and recent work has elucidated several peptides capable of binding to the cholera toxin subunit B.¹ Designing membranes that are able to selectively isolate cholera toxins will enable facile testing and remediation efforts.

In this work, a series of hydrogels formed from a maleimide-functionalized, four-armed poly(ethylene glycol) (PEG) and one of four di-cysteine terminated cholera toxin-binding peptides were synthesized and characterized. Hydrogels were synthesized at constant concentrations via a thiol-ene click chemistry reaction. The mechanical properties and correlation lengths of all gels were similar as determined by rheology and small-angle neutron scattering (SANS) respectively. All gels rejected non-cholera toxin proteins at high molecular weight (> 66 kDa). However, only gels with the high peptide binding capacity were able to selectively uptake the cholera toxin (85 kDa), demonstrating the selective transport ability of the peptide-containing gels. Together, this work demonstrates the potential for biologically-inspired selectively-diffusive membranes for the remediation of water-borne disease.

[1] Yu RK, et al., Glycobiology, 2016, 10.1093/glycob/cww015.