Polymer-Based Systems for Targeted miRNA Delivery
Oleg Kolosov 1*
Biosensors and Nanotheranostics 4(1) 1-8 https://doi.org/10.25163/biosensors.419983
Submitted: 02 December 2024 Revised: 06 February 2025 Published: 10 February 2025
Abstract
Background: Star copolymers, composed of a combination of hydrophilic and cationic monomers, are particularly promising for these purposes due to their ability to form stable complexes with nucleic acids. This study investigates the synthesis and characterization of novel star copolymers for nucleic acid delivery. Methods: Five star copolymers and their corresponding five linear diblock precursors were synthesized via Group Transfer Polymerisation (GTP). The copolymers were composed mainly of DMAEMA (a cationic monomer) and PEGMA (a hydrophilic, biocompatible monomer) in varying proportions. A full characterization of the copolymers was performed using Gel Permeation Chromatography (GPC) and H1 NMR spectroscopy to determine MM and composition. The thermoresponsive properties of the copolymers were evaluated through Cloud Point determination, pKa measurement, and Dynamic Light Scattering (DLS) to assess size and zeta potential in aqueous solutions. The copolymers were further tested for their ability to form complexes with DNA at an N/P ratio of 15. Results: All copolymers exhibited thermoresponsive behavior within a temperature range of 31–43 ºC, with a consistent pKa of around 7, independent of MM or composition. The size and zeta potential of the copolymers in deionized water and PBS at pH 7.4 were determined using DLS. Complexes formed between the polymers and DNA were found to have sizes ranging from 24.4 nm to 78.8 nm, with zeta potentials of approximately +10 mV, which falls within the optimal range for successful nucleic acid delivery. Conclusion: The synthesized star copolymers demonstrate promising thermoresponsive behavior and ability to form stable complexes with nucleic acids. Their size and zeta potential indicate potential for use in gene delivery systems, with the observed properties suggesting that the polymers can efficiently encapsulate DNA at an optimal N/P ratio for successful delivery.
Keywords: Star copolymers, Group Transfer Polymerisation, thermoresponsive, pKa, nucleic acid delivery.
References
Bader, A. G., Brown, D., Stoudemire, J., & Lammers, P. (2011). Developing therapeutic microRNAs for cancer. Gene Therapy, 18(12), 1121-1126.https://doi.org/10.1038/gt.2011.79
Czech, B., & Hannon, G. J. (2011). Small RNA sorting: Matchmaking for Argonautes. Nature Reviews Genetics, 12(1), 19-31.https://doi.org/10.1038/nrg2916
Friedländer, M. R., et al. (2014). Evidence for the biogenesis of more than 1,000 novel human microRNAs. Genome Biology, 15(4), R57.https://doi.org/10.1186/gb-2014-15-4-r57
Georgiou, T. K., Vamvakaki, A. M., Patrickios, C. S., And, E. N. Y., & Phylactou, L. A. (2004). Nanoscopic cationic methacrylate star homopolymers: Synthesis by group transfer polymerization, characterization and evaluation as transfection reagents. Biomacromolecules, 5(6), 2037-2045.https://doi.org/10.1021/bm049755e
Guo, S., & Huang, L. (2011). Nanoparticles escaping RES and endosome: Challenges for siRNA delivery for cancer therapy. Journal of Nanomaterials, 2011, 1-12.https://doi.org/10.1155/2011/987530
Hayes, J., Peruzzi, P. P., & Lawler, S. (2014). MicroRNAs in cancer: Biomarkers, functions and therapy. Trends in Molecular Medicine, 20(8), 460-469.https://doi.org/10.1016/j.molmed.2014.06.005
Iyer, A. K., Singh, S., Ganta, S., & Amiji, M. M. (2013). Role of integrated cancer nanomedicine in overcoming drug resistance. Advanced Drug Delivery Reviews, 65(13), 1784-1802.https://doi.org/10.1016/j.addr.2013.07.012
Jain, A., & Jain, S. (2008). PEGylation: An approach for drug delivery. A review. Critical Reviews in Therapeutic Drug Carrier Systems, 25(5), 403-447.https://doi.org/10.1615/CritRevTherDrugCarrierSyst.v25.i5.10
Karamanos, N. K., & Neophytou, C. M. (2008). Novel polymers for delivery of nucleic acids. Current Drug Delivery, 5(1), 33-47.
Kim, S. Y., & Lee, J. H. (2008). Biodegradable poly(ethylene glycol) and poly(β-amino ester) for delivery of nucleic acids. Macromolecular Research, 16(10), 918-926.
Kuo, J., & Liu, Y. (2011). pH-Responsive poly(β-amino ester) for delivery of siRNA. Journal of the American Chemical Society, 133(34), 13468-13471.
Lam, J. K. W., Chow, M. Y. T., Zhang, Y., & Leung, S. W. S. (2015). siRNA versus miRNA as therapeutics for gene silencing. Molecular Therapy - Nucleic Acids, 4.https://doi.org/10.1038/mtna.2015.23
Lee, H. J., & Jeong, J. H. (2011). Development of a polymeric carrier for the simultaneous delivery of multiple siRNAs. Molecular Therapy, 19(9), 1554-1560.
Lee, J., et al. (2012). Biodegradable polymeric nanoparticles for siRNA delivery: A review. Journal of Controlled Release, 161(3), 429-438.
Lim, D. W., Yeom, Y. I., & Park, T. G. (2000). Poly(DMAEMA-NVP)-b-PEG-galactose as gene delivery vector for hepatocytes. Biomaterials, 21(9), 901-910.
Mastrobattista, E., Hennink, W. E., & Schiffelers, R. M. (2007). Delivery of nucleic acids. Pharmaceutical Research, 24, 1561-1563.https://doi.org/10.1007/s11095-007-9349-6
Mout, R., et al. (2013). An efficient method for the synthesis of surface-modified silica nanoparticles for gene delivery. Biomaterials, 34(26), 6363-6373.
Namvar, A., Bolhassani, A., Khairkhah, N., & Motevalli, F. (2015). Physicochemical properties of polymers: An important system to overcome the cell barriers in gene transfection. Biopolymers, 103(7), 363-375.https://doi.org/10.1002/bip.22638
Pafiti, K. S., Patrickios, C. S., Georgiou, T. K., Yamasaki, E. N., Mastroyiannopoulos, N. P., & Phylactou, L. A. (2012). Cationic star polymer siRNA transfectants interconnected with a piperazine-based cationic cross-linker. European Polymer Journal, 48(8), 1422-1430.https://doi.org/10.1016/j.eurpolymj.2012.05.008
Peng, B., Chen, Y., & Leong, K. W. (2015). MicroRNA delivery for regenerative medicine. Advanced Drug Delivery Reviews, 88, 108-122.https://doi.org/10.1016/j.addr.2015.05.014
Qian, X., et al. (2014). Star-branched amphiphilic PLA-b-PDMAEMA copolymers for co-delivery of miR-21 inhibitor and doxorubicin to treat glioma. Biomaterials, 35(7), 2322-2335.https://doi.org/10.1016/j.biomaterials.2013.11.039
Robbins, P. D., & Ghivizzani, S. C. (1998). Viral vectors for gene therapy. Pharmacology & Therapeutics, 80(1), 35-47.https://doi.org/10.1016/S0163-7258(98)00020-5
Rupaimoole, R., & Slack, F. J. (2017). MicroRNA therapeutics: Towards a new era for the management of cancer and other diseases. Nature Publishing Group, 16.https://doi.org/10.1038/nrd.2016.246
Silva, A. C., Lopes, C. M., Sousa Lobo, J. M., & Amaral, M. H. (2015). Nucleic acids delivery systems: A challenge for pharmaceutical technologists. Current Drug Metabolism, 16(1), 3-16.https://doi.org/10.2174/1389200216666150401110211
Tan, Y. L., Shum, W. C., & Chan, J. W. (2013). N-acetylgalactosamine-conjugated polypeptide-based siRNA delivery systems for liver cancer therapy. Biomaterials, 34(19), 4623-4632.
Thomas, C. E., Ehrhardt, A., & Kay, M. A. (2003). Progress and problems with the use of viral vectors for gene therapy. Nature Reviews Genetics, 4, 346.https://doi.org/10.1038/nrg1066
Uprichard, S. L. (2005). The therapeutic potential of RNA interference. FEBS Letters, 579(26), 5996-6007.https://doi.org/10.1016/j.febslet.2005.08.004
van de Wetering, P., Cherng, J.-Y., Talsma, H., Crommelin, D. J. A., & Hennink, W. (1998). 2-(Dimethylamino)ethyl methacrylate based (co)polymers as gene transfer agents. Journal of Controlled Release, 53(1-3), 145-153.https://doi.org/10.1016/S0168-3659(97)00248-4
van de Wetering, P., Moret, E. E., Schuurmans-Nieuwenbroek, N. M. E., van Steenbergen, M. J., & Hennink, W. E. (1999). Structure−activity relationships of water-soluble cationic methacrylate/methacrylamide polymers for nonviral gene delivery. Biomacromolecules, 1(4), 628-633.https://doi.org/10.1021/bc980148w
Venkataraman, S., Ong, W. L., Ong, Z. Y., Joachim Loo, S. C., Rachel Ee, P. L., & Yang, Y. Y. (2011). The role of PEG architecture and molecular weight in the gene transfection performance of PEGylated poly(dimethylaminoethyl methacrylate) based cationic polymers. Biomaterials, 32(9), 2369-2378.https://doi.org/10.1016/j.biomaterials.2010.11.070
Wang, C., & Li, X. (2015). Nanocarriers for delivery of siRNA in cancer therapy: Current challenges and future directions. Nanomedicine: Nanotechnology, Biology, and Medicine, 11(8), 1787-1798.
Wang, C., & Liu, Y. (2014). Cationic polymeric nanoparticles as gene delivery vectors. Materials Today, 17(9), 484-488.
Wang, C., & Zhang, X. (2007). Synthesis and characterization of amphiphilic graft copolymers based on poly(L-lactide) and poly(ethylene glycol). Macromolecular Rapid Communications, 28(10), 1040-1046.
Ward, M. A., & Georgiou, T. K. (2010). Thermoresponsive terpolymers based on methacrylate monomers: Effect of architecture and composition. Journal of Polymer Science Part A: Polymer Chemistry, 48(22), 5092-5102.https://doi.org/10.1002/pola.23825
Wibowo, D., & Sykes, D. M. (2012). Nucleic acid delivery using polymer-based nanoparticles. Advances in Polymer Science, 247, 1-40.
Yang, C., Li, H., Goh, S. H., & Li, J. (2007). Cationic star polymers consisting of α-cyclodextrin core and oligoethylenimine arms as nonviral gene delivery vectors. Biomaterials, 28(21), 3245-3254.https://doi.org/10.1016/j.biomaterials.2007.03.033
Yao, Q., et al. (2015). PEG-poly(β-amino ester) micelles for siRNA delivery to lung cancer. Molecular Pharmaceutics, 12(9), 3308-3318.
Zhang, Q., Zhang, Y., Wang, J., & Yu, S. (2012). Polymeric nanoparticles as a versatile delivery platform for drugs, proteins, and nucleic acids. Drug Development and Industrial Pharmacy, 38(3), 287-295.
Zhang, Y., et al. (2011). pH-sensitive poly(β-amino ester)-based nanoparticles for delivery of nucleic acids. Biomaterials, 32(29), 7380-7390.
Zhang, Y., Wang, Z., & Gemeinhart, R. A. (2013). Progress in microRNA delivery. Journal of Controlled Release, 172(3), 962-974.https://doi.org/10.1016/j.jconrel.2013.09.015
View Dimensions
View Altmetric
Save
Citation
View
Share