Light-activated Polymerization Methods Unlock New Potential for Intracellular Applications

Synthetic polymers are integral components in cell biology, utilized as carriers for drugs and DNA, fluorescent probes for cellular sensing, bioinks for tissue engineering, and as mimics of biological structures, like artificial antigen-presenting cells. However, the synthesis of polymers within living cells poses significant challenges due to the intricate and often inhospitable intracellular conditions that can impede these reactions.

In a groundbreaking study earlier this year, a research team led by Prof. Geng Jin at the Shenzhen Institute of Advanced Technology (SIAT), part of the Chinese Academy of Sciences, introduced two novel methods for achieving intracellular polymerization through light stimuli. These innovative techniques, discussed in detail in the journal Nature Protocols, represent a significant advancement in the field of biomedical engineering.

The researchers successfully demonstrated the initiation of various polymerization reactions, including reversible addition–fragmentation chain transfer and free radical polymerization. This was accomplished by introducing highly biocompatible monomers into live cells and activating them using light. The advantage of light-mediated initiation lies in its ability to provide precise spatial and temporal control over the polymerization process, featuring rapid reaction kinetics while ensuring good biocompatibility.

Notably, this polymerization process can yield macromolecular structures within a brief timeframe of 5 to 10 minutes, depending on the specific wavelength employed. This efficiency minimizes cellular stress and helps prevent damage to intracellular components. The potential applications for this methodology are extensive; it could facilitate modulation of critical cellular functions such as motility, differentiation, proliferation, and intercellular interactions, positioning it as a promising strategy for therapeutic development.

The protocol elaborates on the technical intricacies of the two methods: traditional photo-polymerization via free radicals and photoinduced electron/energy transfer-reversible addition–fragmentation chain transfer polymerization. Furthermore, it outlines the procedures for the synthesis and isolation of His-tagged intracellular polymers, thereby providing a comprehensive resource for researchers in the field.

Prof. Geng remarked on the implications of this work, stating, “The ability to produce customized functional polymers within cells brings us closer to advanced therapeutic strategies and innovative bioimaging methods. Our study could represent a captivating frontier in the realm of biomedicine, holding great promise for future developments.”