Science 357, 1118–1122 (2017)

Credit: AAAS

The fabrication of 'smart' textiles or wearable technologies, which respond to external stimuli, typically requires either the use of synthetic fibers or the coating or dyeing of natural fibers. These coatings or dyes are eventually worn or washed off, limiting the material's useful lifespan. Natalio et al. have now circumvented this problem by engineering cotton in which the added functionality is incorporated during fiber formation, thus preventing it from being worn away over time. After determining that the conjugation of a glucose moiety facilitated uptake of pigments into the outermost epidermal cell layer of cotton ovules cultured in vitro, the researchers synthesized two glucose-functionalized compounds for incorporation into the growing cotton fibers. Incubating fertilized ovules with one of these compounds, a glucose-conjugated 6-carboxyfluorescein (6CF-Glc), led to the production of fluorescent fibers. Substitution of 6CF-Glc with the other compound, a glucose-conjugated macrocycle caging a dysprosium(III) ion (Glc-DOTA-Dy(III)), yielded magnetic fibers instead. Various microscopic and spectroscopic methods verified that these exogenous moieties were successfully incorporated and that the morphologies of the functionalized fibers were largely consistent with that of raw fibers. In the future, similar approaches may be used for the addition of desired functionalities to other biological materials such as bamboo, silk, or flax, leading to new generations of engineered biomaterials.