"Smart" injectable hydrogel bioinks for 3D bioprinting applications
With the advent of additive manufacturing techniques, there is an ever-growing need for the development of new materials and fillers that can be integrated with these modern material deposition methods. Polymers constitute a major class of 3D-printable materials and have already found uses in multifarious fields spanning from structural materials, (bio-)electronics, soft robotic components, biomaterials and drug delivery microdevices, to daily use articles. Polymeric hydrogels belong to a class of soft materials comprising polymer networks crosslinked by hydrophilic or amphiphilic polymeric chains that can retain large volumes of water. Hydrogels, and especially those that can undergo shear-thinning, have already been adopted in 3D printing processes owing to their relative ease of preparation and chemical versatility. In the case of natural hydrogels, crosslinking takes place with the use of non-covalent dynamic bonds, such as hydrogen bonds, ionic bonds, and hydrophobic interactions which result in the reversible formation of a crosslinked polymer network. An interesting class of hydrogels are the so called “smart hydrogels” where the crosslinking mechanism comprises the use of responsive polymers, endowing the formation of the crosslink mechanism responsive to physiochemical cues such as changes in temperature, pH, or other stimuli such as application of light, ultrasound irradiation etc. In our laboratory we study the development of injectable polymer networks that can undergo reversible gelation under mild conditions. These soft materials can host living cell populations without affecting their viability and other key functions, and can also act as injectable cell delivery devices.
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.
Microparticles for controlled delivery of multiple drug molecules
(in collaboration with Dr Gareth Williams, UCL SoP)
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.
With the advent of additive manufacturing techniques, there is an ever-growing need for the development of new materials and fillers that can be integrated with these modern material deposition methods. Polymers constitute a major class of 3D-printable materials and have already found uses in multifarious fields spanning from structural materials, (bio-)electronics, soft robotic components, biomaterials and drug delivery microdevices, to daily use articles. Polymeric hydrogels belong to a class of soft materials comprising polymer networks crosslinked by hydrophilic or amphiphilic polymeric chains that can retain large volumes of water. Hydrogels, and especially those that can undergo shear-thinning, have already been adopted in 3D printing processes owing to their relative ease of preparation and chemical versatility. In the case of natural hydrogels, crosslinking takes place with the use of non-covalent dynamic bonds, such as hydrogen bonds, ionic bonds, and hydrophobic interactions which result in the reversible formation of a crosslinked polymer network. An interesting class of hydrogels are the so called “smart hydrogels” where the crosslinking mechanism comprises the use of responsive polymers, endowing the formation of the crosslink mechanism responsive to physiochemical cues such as changes in temperature, pH, or other stimuli such as application of light, ultrasound irradiation etc. In our laboratory we study the development of injectable polymer networks that can undergo reversible gelation under mild conditions. These soft materials can host living cell populations without affecting their viability and other key functions, and can also act as injectable cell delivery devices.
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.
Microparticles for controlled delivery of multiple drug molecules
(in collaboration with Dr Gareth Williams, UCL SoP)
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.