George Pasparakis
Curriculum Details
- 2009 - PhD in Pharmaceutics, University of Nottingham, School of Pharmacy, Division of Drug Delivery and Tissue Engineering, United Kingdom
- 2005 - Ptychion in Materials Science, University of Patras, Faculty of Natural Sciences, Department of Materials Science, Greece
Gold nanoparticles for cancer therapy and diagnosis
Gold nanoparticles constitute an excellent platform for the nano-enabled targeted delivery of anticancer drugs and diagnostic biomarkers. We are currently developing gold nanoparticles of various sizes and shapes in an effort to exploit their unique optical properties in the development of novel laser guided cancer therapies. In the present project, we develop radically new therapeutic protocols that combine lasers and nanoparticles (these are small sized materials with diameters thousands of times smaller than the thickness of a human hair) to direct drugs at the diseased sites of the body in a specific manner without damaging healthy tissue. The nanoparticles freely circulate in the bloodstream and carry toxic drugs but will only release their lethal cargo when activated by laser light. By pointing the laser beam directly to the diseased tissue, it is possible to treat cancerous tumors by activating the nanoparticles to release the drugs only within tumor areas and not to surrounding healthy tissue. We envision that in the future oncologists will be able to treat cancers in a dynamic manner by continually adjusting drug dosage during treatment by gaining constant feedback information on the tumours' response to therapy by simultaneous imaging of the diseased area during treatment.
"Smart" polymers for targeted drug delivery
Although current cancer chemotherapies have significantly improved patients' prognosis and compliance, they often lack tumour targeting specificity which compromises the therapeutic outcome. In this project, we study the use of block copolymers as nanocarriers of anticancer drugs that gradually accumulate at the tumour sites through systemic circulation. By application of an external stimulus such as light, or ultrasound, these nanoparticles are activated and release their cytotoxic cargo only at the targeted sites in a highly specific manner. This approach maximizes the accumulation of the drug molecules at the site of interest and hence improve the therapeutic outcome while maintaining low drug exposure of the healthy tissue. We synthesize our nanomaterials by controlled polymerization routes which allow for unprecedented control of the molecular architecture and develop in vitro and in vivo models to screen the best synthetic candidates for further translational exploitation in nanomedicinal therapeutics.
Biomaterials for cardiac tissue regeneration
Myocardial infarction is the number one killer disease in the UK and the western world and is also the second most prevalent cause of disability. Despite the tremendous advances in the field of interventional cardiology, and the substantial improvement of patient prognosis, there is still no cure for MCI. Current therapies primarily focus on surgery procedures to (partially) restore cardiac rhythm, lowering of risk factors leading to recurrence (i.e. by chronic drug administration), and mechanical support to maintain blood circulation, however, all these approaches do not provide cure from disease.
In this project, we develop novel polymeric biomaterials in an effort to construct "cellular-glues" that can be directly applied to the damaged myocardium and promote the regeneration of new functional tissue in order to fully restore the cardiac function. More specifically, we synthesize biocompatible polymers by controlled polymerization routes that promote the formation of cell spheroid formation and augment their surface immobilization properties at the site of injury.
Microparticles for controlled delivery of multiple drug molecules
(in collaboration with Dr Gareth Williams, UCL School of Pharmacy)
In many therapeutic senarios, it is necessary to administer multiple drug molecules in order to elicit an effective therapeutic response. For example, certain types of cancer, require the administration of cytotoxic drug cocktails that result in severe side effects and compromise patient compliance significantly. In this project, we exploit electrohydrodynamic methods to synthesize polymeric microparticles of complex texture and architecture in order to use them as drug reservoirs that carry multiple drug molecules. These microparticles allow the simultaneous delivery of different drug molecules in a single platform and could potentially lead to more precise targeting of cancers without affecting healthy tissue regardless of their complex molecular cargo.
1. Emamzadeh, M., Desmaële, D., Couvreur, P., & Pasparakis, G. (2018) Dual Controlled Delivery of Squalenoyl-Gemcitabine and Paclitaxel using Thermo-Responsive Polymeric Micelles for Pancreatic Cancer Journal of Materials Chemistry B, 6, 2230-2239 DOI:10.1039/C7TB02899G
2. Joubert, F., Martin, L., Perrier, S., & Pasparakis, G. (2017). Development of a gemcitabine-polymer conjugate with prolonged cytotoxicity against a pancreatic cancer cell line. ACS Macro Letters , 6, 535–540. doi: 10.1021/acsmacrolett.7b00160
3. Amaral, A. J. R., & Pasparakis, G. (2016). Rapid Formation of Cell Aggregates and Spheroids Induced by a “Smart” Boronic Acid Copolymer. ACS Applied Materials & Interfaces, 8 (35), 22930–22941. doi: 10.1021/acsami.6b07911
4. Pasparakis, G., Manouras, T., Selimis, A., Vamvakaki, M., & Argitis, P. (2011). Laser-induced cell detachment and patterning with photodegradable polymer substrates. Angewandte Chemie International Edition, 50 (18), 4142-4145. doi:10.1002/anie.201007310
5. Amaral, A. J. R., & Pasparakis, G. (2015). Macromolecular cell surface engineering for accelerated and reversible cellular aggregation. Chemical Communications, 51 (99), 17556-17559. doi:10.1039/c5cc07001e
6. Pasparakis, G., Manouras, T., Vamvakaki, M., & Argitis, P. (2014). Harnessing photochemical internalization with dual degradable nanoparticles for combinatorial photo-chemotherapy. Nature Communications, 5, 3623. doi:10.1038/ncomms4623
7. Pasparakis, G. (2013). Light-induced generation of singlet oxygen by naked gold nanoparticles and its implications to cancer cell phototherapy. Small, 9 (24), 4130-4134. doi:10.1002/smll.201301365
8. Magnusson, J. P., Khan, A., Pasparakis, G., Saeed, A. O., Wang, W., & Alexander, C. (2008). Ion-sensitive "isothermal" responsive polymers prepared in water. Journal of the American Chemical Society, 130 (33), 10852-10853. doi:10.1021/ja802609r
9. Pasparakis, G., & Alexander, C. (2008). Sweet talking double hydrophilic block copolymer vesicles. Angewandte Chemie International Edition, 47 (26), 4847-4850. doi:10.1002/anie.200801098
10. Pasparakis, G., Cockayne, A., & Alexander, C. (2007). Control of bacterial aggregation by thermoresponsive glycopolymers. Journal of the American Chemical Society, 129 (36), 11014-11015. doi:10.1021/ja074349z