Polymerization reactions conducted inside cells must be compatible with the complex intracellular environment, which contains numerous molecules and functional groups that could potentially prevent or quench polymerization reactions. Here we report a strategy for directly synthesizing unnatural polymers in cells through free radical photopolymerization using a number of biocompatible acrylic and methacrylic monomers. This offers a platform to manipulate, track and control cellular behaviour by the in cellulo generation of macromolecules that have the ability to alter cellular motility, label cells by the generation of fluorescent polymers for long-term tracking studies, as well as generate a variety of nanostructures within cells. It is remarkable that free radical polymerization chemistry can take place within such complex cellular environments. This demonstration opens up a multitude of new possibilities for how chemists can modulate cellular function and behaviour and for understanding cellular behaviour in response to the generation of free radicals.
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Nicolas, J., Mura, S., Brambilla, D., Mackiewicz, N. & Couvreur, P. Design, functionalization strategies and biomedical applications of targeted biodegradable/biocompatible polymer-based nanocarriers for drug delivery. Chem. Soc. Rev. 42, 1147–1235 (2013).
Green, J. J. & Elisseeff, J. H. Mimicking biological functionality with polymers for biomedical applications. Nature 540, 386–394 (2016).
Howes, P. D., Chandrawati, R. & Stevens, M. M. Colloidal nanoparticles as advanced biological sensors. Science 346, 1247390 (2014).
Tang, F., He, F., Cheng, H. & Li, L. Self-assembly of conjugated polymer-Ag@SiO2 hybrid fluorescent nanoparticles for application to cellular imaging. Langmuir 26, 11774–11778 (2010).
Tonga, G. Y. et al. Supramolecular regulation of bioorthogonal catalysis in cells using nanoparticle-embedded transition metal catalysts. Nat. Chem. 7, 597–603 (2015).
Yusop, R. M., Unciti-Broceta, A., Johansson, E. M. V., Sanchez-Martin, R. M. & Bradley, M. Palladium-mediated intracellular chemistry. Nat. Chem. 3, 239–243 (2011).
Collins, M. N. & Birkinshaw, C. Hyaluronic acid based scaffolds for tissue engineering—a review. Carbohydr. Polym. 92, 1262–1279 (2013).
Tasoglu, S. & Demirci, U. Bioprinting for stem cell research. Trends Biotechnol. 31, 10–19 (2013).
Hutmacher, D. W. Scaffolds in tissue engineering bone and cartilage. Biomaterials 21, 2529–2543 (2000).
Meyer, R. A. et al. Biodegradable nanoellipsoidal artificial antigen presenting cells for antigen specific T-cell activation. Small 11, 1519–1525 (2015).
Hu, C.-M. J. et al. Erythrocyte membrane-camouflaged polymeric nanoparticles as a biomimetic delivery platform. Proc. Natl Acad. Sci. USA 108, 10980–10985 (2011).
Lodish, H. et al. Molecular Cell Biology (W. H. Freeman, 2007).
Zhu, Y., Huang, W., Lee, S. S. K. & Xu, W. Crystal structure of a polyphosphate kinase and its implications for polyphosphate synthesis. EMBO Rep. 6, 681–687 (2005).
Anderson, A. J., Haywood, G. W. & Dawes, E. A. Biosynthesis and composition of bacterial poly(hydroxyalkanoates). Int. J. Biol. Macromol. 12, 102–105 (1990).
Kessler, B. & Witholt, B. Factors involved in the regulatory network of polyhydroxyalkanoate metabolism. J. Biotechnol. 86, 97–104 (2001).
Adams, D. J. Fungal cell wall chitinases and glucanases. Microbiology 150, 2029–2035 (2004).
Arakawa, Y. et al. Genomic organization of the Klebsiella pneumoniae cps region responsible for serotype K2 capsular polysaccharide synthesis in the virulent strain Chedid. J. Bacteriol. 177, 1788–1796 (1995).
Chien, L. J. & Lee, C. K. Enhanced hyaluronic acid production in Bacillus subtilis by coexpressing bacterial hemoglobin. Biotechnol. Prog. 23, 1017–1022 (2007).
Brangwynne, C. P., Tompa, P. & von Pappu, R. Polymer physics of intracellular phase transitions. Nat. Phys. 11, 899–904 (2015).
Rehm, B. H. A. Bacterial polymers: biosynthesis, modifications and applications. Nat. Rev. Microbiol. 8, 578–592 (2010).
Yang, S. H. et al. Mussel-inspired encapsulation and functionalization of individual yeast cells. J. Am. Chem. Soc. 133, 2795–2797 (2011).
Tytgat, L. et al. in 3D Printing and Biofabrication (eds Ovsianikov, A., Yoo, J. & Mironov, V.) Vol. 96, 1–43 (Springer International, 2017).
Williams, C. G., Malik, A. N., Kim, T. K., Manson, P. N. & Elisseeff, J. H. Variable cytocompatibility of six cell lines with photoinitiators used for polymerizing hydrogels and cell encapsulation. Biomaterials 26, 1211–1218 (2005).
Yang, J. et al. Nanoencapsulation of individual mammalian cells with cytoprotective polymer shell. Biomaterials 133, 253–262 (2017).
Xia, Y. et al. Photopolymerized injectable water-soluble maleilated chitosan/poly(ethylene glycol) diacrylate hydrogels as potential tissue engineering scaffolds. J. Photopolym. Sci. Technol. 30, 33–40 (2017).
Pathak, C. P., Sawhney, A. S. & Hubbell, J. A. Rapid photopolymerization of immunoprotective gels in contact with cells and tissue. J. Am. Chem. Soc. 114, 8311–8312 (1992).
Magennis, E. P. et al. Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling. Nat. Mater. 13, 748–755 (2014).
Kim, J. Y. et al. Cytocompatible polymer grafting from individual living cells by atom‐transfer radical polymerization. Angew. Chem. Int. Ed. 55, 15306–15309 (2016).
Niu, J. et al. Engineering live cell surfaces with functional polymers via cytocompatible controlled radical polymerization. Nat. Chem. 9, 537–545 (2017).
Ma, X. et al. Construction and potential applications of a functionalized cell with an intracellular mineral scaffold. Angew. Chem. Int. Ed. 50, 7414–7417 (2011).
Sweeney, R. Y. et al. Bacterial biosynthesis of cadmium sulfide nanocrystals. Chem. Biol. 11, 1553–1559 (2004).
Klaus, T., Joerger, R., Olsson, E. & Granqvist, C.-G. Silver-based crystalline nanoparticles, microbially fabricated. Proc. Natl Acad. Sci. USA 96, 13611–13614 (1999).
Said, El,W. A., Cho, H. Y., Yea, C. H. & Choi, J. W. Synthesis of metal nanoparticles inside living human cells based on the intracellular formation process. Adv. Mater. 26, 910–918 (2014).
Li, Y. et al. Mechanism-oriented controllability of intracellular quantum dots formation: the role of glutathione metabolic pathway. ACS Nano 7, 2240–2248 (2013).
Cui, R. et al. Living yeast cells as a controllable biosynthesizer for fluorescent quantum dots. Adv. Funct. Mater. 19, 2359–2364 (2009).
Bryant, S. J., Nuttelman, C. R. & Anseth, K. S. Cytocompatibility of UV and visible light photoinitiating systems on cultured NIH/3T3 fibroblasts in vitro. J. Biomater. Sci. Polym. Ed. 11, 439–457 (2000).
Fedorovich, N. E. et al. The effect of photopolymerization on stem cells embedded in hydrogels. Biomaterials 30, 344–353 (2009).
Schweikl, H., Spagnuolo, G. & Schmalz, G. Genetic and cellular toxicology of dental resin monomers. J. Dent. Res. 85, 870–877 (2006).
Issa, Y., Watts, D. C., Brunton, P. A., Waters, C. M. & Duxbury, A. J. Resin composite monomers alter MTT and LDH activity of human gingival fibroblasts in vitro. Dent. Mater. 20, 12–20 (2004).
Vasey, P. A. et al. Phase I clinical and pharmacokinetic study of PK1 [N-(2-hydroxypropyl)methacrylamide copolymer doxorubicin]: first member of a new class of chemotherapeutic agents—drug–polymer conjugates. Clin. Cancer Res. 5, 83–94 (1999).
Callahan, J. & Kopeček, J. Semitelechelic HPMA copolymers functionalized with triphenylphosphonium as drug carriers for membrane transduction and mitochondrial localization. Biomacromolecules 7, 2347–2356 (2006).
Kopecek, J. & Kopečková, P. HPMA copolymers: origins, early developments, present and future. Adv. Drug Deliv. Rev. 62, 122–149 (2010).
Lilly, J. L., Romero, G., Xu, W., Shin, H. Y. & Berron, B. J. Characterization of molecular transport in ultrathin hydrogel coatings for cellular immunoprotection. Biomacromolecules 16, 541–549 (2015).
Dröge, W. Free radicals in the physiological control of cell function. Physiol. Rev. 82, 47–95 (2002).
Armstrong, D. Advanced Protocols in Oxidative Stress II (Humana, 2010).
Ridley, A. J. et al. Cell migration: integrating signals from front to back. Science 302, 1704–1709 (2003).
Hood, J. D. & Cheresh, D. A. Role of integrins in cell invasion and migration. Nat. Rev. Cancer 2, 91–100 (2002).
Scharffetter-Kochanek, K. et al. UV-induced reactive oxygen species in photocarcinogenesis and photoaging. J. Biol. Chem. 378, 1247–1257 (1997).
Roca-Cusachs, P., Conte, V. & Trepat, X. Quantifying forces in cell biology. Nat. Cell Biol. 19, 742–751 (2017).
Poirier, M. G. & Marko, J. F. Effect of internal friction on biofilament dynamics. Phys. Rev. Lett. 88, 228103 (2002).
Mizuno, D., Tardin, C., Schmidt, C. F. & MacKintosh, F. C. Nonequilibrium mechanics of active cytoskeletal networks. Science 315, 370–373 (2007).
Vasconcellos, C. A. et al. Reduction in viscosity of cystic-fibrosis sputum in-vitro by gelsolin. Science 263, 969–971 (1994).
Nakamura, F., Osborn, E., Janmey, P. A. & Stossel, T. P. Comparison of filamin A-induced cross-linking and Arp2/3 complex-mediated branching on the mechanics of actin filaments. J. Biochem. 277, 9148–9154 (2002).
Blanchoin, L. & Pollard, T. D. Interaction of actin monomers with acanthamoeba actophorin (ADF/cofilin) and profilin. J. Biochem. 273, 25106–25111 (1998).
Püspöki, Z., Storath, M., Sage, D. & Unser, M. Focus on bio-image informatics, in Proc. AAECB Vol. 219, 69–93 (Springer, 2016).
Boudaoud, A. et al. FibrilTool, an ImageJ plug-in to quantify fibrillar structures in raw microscopy images. Nat. Protoc. 9, 457–463 (2014).
Wang, Z. et al. Long-term fluorescent cellular tracing by the aggregates of AIE bioconjugates. J. Am. Chem. Soc. 135, 8238–8245 (2013).
Major, M. D. & Torkelson, J. M. Fluorescence of vinyl aromatic polyelectrolytes: effects of conformation, concentration, and molecular weight of sodium poly (styrene sulfonate). Macromolecules 1986, 2806–2810 (1986).
Ander, P. & Mahmoudhagh, M. K. Excimer formation of poly (styrenesulfonic acid) and its salts in solution. Macromolecules 15, 214–216 (1982).
Yan, J. J. et al. Polymerizing nonfluorescent monomers without incorporating any fluorescent agent produces strong fluorescent polymers. Adv. Mater. 24, 5617–5624 (2012).
Gerweck, L. E. & Seetharaman, K. Cellular pH gradient in tumor versus normal tissue: potential exploitation for the treatment of cancer. Cancer Res. 56, 1194–1198 (1996).
Johnson, D. E., Ostrowski, P., Jaumouillé, V. & Grinstein, S. The position of lysosomes within the cell determines their luminal pH. J. Cell Biol. 212, 677–692 (2016).
Bridges, J. W. & Williams, R. T. The fluorescence of indoles and aniline derivatives. Biochem. J. 107, 225–237 (1968).
Goswami, T. K. et al. Ferrocene-conjugated copper(ii) complexes of l-methionine and phenanthroline bases: synthesis, structure and photocytotoxic activity. Organometallics 31, 3010–3021 (2012).
Chen, S., Lu, J., Sun, C. & Ma, H. A highly specific ferrocene-based fluorescent probe for hypochlorous acid and its application to cell imaging. Analyst 135, 577–582 (2010).
Kumar, K., Vulugundam, G., Kondaiah, P. & Bhattacharya, S. Co-liposomes of redox-active alkyl-ferrocene modified low MW branched PEI and DOPE for efficacious gene delivery in serum. J. Mater. Chem. B 3, 2318–2330 (2015).
Vankayala, R., Kalluru, P., Tsai, H.-H., Chiang, C.-S. & Hwang, K. C. Effects of surface functionality of carbon nanomaterials on short-term cytotoxicity and embryonic development in zebrafish. J. Mater. Chem. B 2, 1038–1047 (2014).
Blanazs, A., Ryan, A. J. & Armes, S. P. Predictive phase diagrams for RAFT aqueous dispersion polymerization: effect of block copolymer composition, molecular weight and copolymer concentration. Macromolecules 45, 5099–5107 (2012).
Refojo, M. F. Hydrophobic interaction in poly(2-hydroxyethyl methacrylate) homogeneous hydrogel. J. Polym. Sci. A 5, 3103–3113 (1967).
This work was supported by the European Research Council (advanced grant ADREEM ERC-2013-340469) and the Rosetrees Trust (A865). N.T. acknowledges support from the Commonwealth Scholarship Commission and W.L. from the Chinese Scholarship Council. The authors thank the Wellcome Trust for Multi-user Equipment Grant WT104915MA.
The authors declare no competing interests.
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Geng, J., Li, W., Zhang, Y. et al. Radical polymerization inside living cells. Nat. Chem. 11, 578–586 (2019). https://doi.org/10.1038/s41557-019-0240-y
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