Tracking the Biological Incorporation of Exogenous Molecules into Cellulose Fibers with Non-Radioactive Iodinated Glucose

Semi-synthetic biological fabrication explores biological systems and their biosynthetic pathways as inspiration for designing precursor analogs that can be metabolized in a similar manner as the natural substrates by organisms to yield new materials with tailored properties. Here we report the biological incorporation of a metabolizing iodinated glucose analog (2-Deoxy-2-iodo-D-glucose, DIG) into Gossypium hirsutum cotton fibers in an ovule in-vitro model. Structural modifications occur at the level of crystallite arrangement and compaction, with amorphization of the fibers and alteration of the H-bond network between the cellulose nanofibrils. We further show that DIG can serve as a non-radioactive micro computed tomography contrast agent (μCT). The fibers act as glucose sinks that accumulate DIG, enabling its detection by μCT. Quantitative analysis shows that the fibers are more oriented when incubated with DIG. This work demonstrates the advantages of using higher organisms for biological in-situ transformation of economically important raw materials over conventional chemical surface modification processes, thereby providing a scientific foundation for implementing future alternatives and sustainable manufacturing strategies towards a bio-based economy.