Periodic Reporting for period 4 - CADENCE (Catalytic Dual-Function Devices Against Cancer)
Reporting period: 2022-03-01 to 2023-08-31
Despite intense research efforts, cancer continues to be one of the leading causes of death worldwide. By current estimates, in 2030 close to 22 million new cases will be diagnosed and cancer will cause 13 million deaths worldwide. This is so in spite of the wide toolbox of therapies against cancer assembled over the years. It is thus remarkable that little or no therapeutic use has been made of a whole discipline, heterogeneous catalysis, noted for its specificity and for enabling chemical reactions in otherwise passive environments. At least in part, this could be attributed to practical difficulties: the selective delivery of a catalyst to a tumor and the remote activation of its catalytic function after it has reached its target are highly challenging objectives. Only recently, the necessary tools to overcome these problems seem within reach. CADENCE aimed for a radical development in cancer therapy from a new therapeutic perspective. The central hypothesis is that a growing tumor can be treated as a special type of reactor in which environmental conditions (i.e. the tumor microenvironment, TME) can be catalytically tailored to prevent cancer growth. The catalysts would be used to achieve two objectives: a) depletion of molecules essential to tumor growth and b) generation of toxic products in situ.
To implement this novel approach, CADENCE makes use of core concepts of reactor engineering, as well as of ideas borrowed from bio-orthogonal chemistry and controlled drug delivery. CADENCE has developed a range of catalysts capable to perform one or both of the above described functions, a) and b). These catalysts (as well as other types of therapeutic particles) have been delivered in vitro and in vivo using novel Trojan Horse-based strategies (mainly extracellular vesicles, (EVs), with tumor tropism), achieving delivery efficiencies that were several times higher than those of conventional methods (EPR effect). In addition, some of the catalysts developed were endowed with selective activation capabilities, either remotely (using near-infrared (NIR) light) or through local activation, using molecules overexpressed in the TME, such as glutathione (GSH).
CADENCE ambitions are high, addressing all the key steps from catalyst design to in vivo studies. Its results have provided new perspectives in catalytic therapy for oncology, thanks to the advances obtained along two main avenues, namely: i) catalysts able to simultaneously combine therapies against cancer (e.g. starvation therapy through glucose oxidation along with oxygen generation to avoid hypoxia limitations, or production of reactive oxygen species (ROS), along with the simultaneous depletion of antioxidant molecules); ii) new catalytic vehicles with selective targeting capabilities (the catalytic EVs, developed for the first time in CADENCE are new exciting therapeutic vectors with a wealth of unexplored possibilities). In summary, CADENCE contributes novel elements to the therapeutic toolbox against cancer, opening up possibilities that will certainly continue to be developed in the near future.
To implement this novel approach, CADENCE makes use of core concepts of reactor engineering, as well as of ideas borrowed from bio-orthogonal chemistry and controlled drug delivery. CADENCE has developed a range of catalysts capable to perform one or both of the above described functions, a) and b). These catalysts (as well as other types of therapeutic particles) have been delivered in vitro and in vivo using novel Trojan Horse-based strategies (mainly extracellular vesicles, (EVs), with tumor tropism), achieving delivery efficiencies that were several times higher than those of conventional methods (EPR effect). In addition, some of the catalysts developed were endowed with selective activation capabilities, either remotely (using near-infrared (NIR) light) or through local activation, using molecules overexpressed in the TME, such as glutathione (GSH).
CADENCE ambitions are high, addressing all the key steps from catalyst design to in vivo studies. Its results have provided new perspectives in catalytic therapy for oncology, thanks to the advances obtained along two main avenues, namely: i) catalysts able to simultaneously combine therapies against cancer (e.g. starvation therapy through glucose oxidation along with oxygen generation to avoid hypoxia limitations, or production of reactive oxygen species (ROS), along with the simultaneous depletion of antioxidant molecules); ii) new catalytic vehicles with selective targeting capabilities (the catalytic EVs, developed for the first time in CADENCE are new exciting therapeutic vectors with a wealth of unexplored possibilities). In summary, CADENCE contributes novel elements to the therapeutic toolbox against cancer, opening up possibilities that will certainly continue to be developed in the near future.
The main results achieved during CADENCE have been:
• Very significant advances in different experimental techniques, including: protocols to analyze key molecules inside cancer cells or peptides in exosomal membranes; microfluidic bioreactors for 2-D and 3-D culture of cancer cells; new synthetic methods (e.g. by laser and flash pyrolysis) for novel catalytic structures; novel methods to obtain nanoparticle-loaded EVs.
• Synthesis of range of “active nanoparticles” able to work in the tumor microenvironment to achieve: i) prodrug activation in a variety of reactions, in collaboration with the group of Prof. Unciti-Broceta at U. Edinburgh; ii) combined catalytic therapies (starvation by glucose depletion plus oxygen generation; GSH depletion plus ROS generation; radiotherapy enhanced by Pt nanoparticles with simultaneous generation of O2); iii) nanoparticles with ion-sequestration capabilities to disrupt tumor homeostasis.
• Synthesis of the first catalytic EVs using a novel experimental technique (mild CO reduction of metal precursors) that preserves the key properties of their membranes and their use as Trojan Horse nanoparticle delivery vectors, combining catalytic action and selective delivery.
• EVs monitorization methods using either their own metal load or a novel labelling method using PerfectaTM, a high-F molecule that allows real time tracing by F-MRI (collaboration with the group of Prof. Metrangolo at U. Milano).
• Selective catalyst activation methods. Remotely, using NIR light with plasmonic catalysts, or locally, using the high concentrations of certain molecules in the TME.
• A method and prototype for microfluidic capture of exosomes based on affinity binding and their use in liquid biopsy applications.
• Methods to prolong active catalyst life in hostile biological environments, teeming with deactivating S-containing molecules, by enclosing them in a structure that hinders protein diffusion or by using their catalytic action to remove deactivating species.
The above results have been widely disseminated in more than 35 refereed publications, mostly in high impact journals, including Nature Catalysis, Nature Protocols, J. Extracell. Vesicles, Nano Lett., J. Nanobiotechnol.; 7 PhD Thesis have been/are being carried out with direct relationship to CADENCE. In addition, we participated in 38 conferences and workshops, often with invited talks, and organized 2 conferences. The results had considerable social impact, cumulatively reaching 73 media items, including press, radio and TV interviews.
• Very significant advances in different experimental techniques, including: protocols to analyze key molecules inside cancer cells or peptides in exosomal membranes; microfluidic bioreactors for 2-D and 3-D culture of cancer cells; new synthetic methods (e.g. by laser and flash pyrolysis) for novel catalytic structures; novel methods to obtain nanoparticle-loaded EVs.
• Synthesis of range of “active nanoparticles” able to work in the tumor microenvironment to achieve: i) prodrug activation in a variety of reactions, in collaboration with the group of Prof. Unciti-Broceta at U. Edinburgh; ii) combined catalytic therapies (starvation by glucose depletion plus oxygen generation; GSH depletion plus ROS generation; radiotherapy enhanced by Pt nanoparticles with simultaneous generation of O2); iii) nanoparticles with ion-sequestration capabilities to disrupt tumor homeostasis.
• Synthesis of the first catalytic EVs using a novel experimental technique (mild CO reduction of metal precursors) that preserves the key properties of their membranes and their use as Trojan Horse nanoparticle delivery vectors, combining catalytic action and selective delivery.
• EVs monitorization methods using either their own metal load or a novel labelling method using PerfectaTM, a high-F molecule that allows real time tracing by F-MRI (collaboration with the group of Prof. Metrangolo at U. Milano).
• Selective catalyst activation methods. Remotely, using NIR light with plasmonic catalysts, or locally, using the high concentrations of certain molecules in the TME.
• A method and prototype for microfluidic capture of exosomes based on affinity binding and their use in liquid biopsy applications.
• Methods to prolong active catalyst life in hostile biological environments, teeming with deactivating S-containing molecules, by enclosing them in a structure that hinders protein diffusion or by using their catalytic action to remove deactivating species.
The above results have been widely disseminated in more than 35 refereed publications, mostly in high impact journals, including Nature Catalysis, Nature Protocols, J. Extracell. Vesicles, Nano Lett., J. Nanobiotechnol.; 7 PhD Thesis have been/are being carried out with direct relationship to CADENCE. In addition, we participated in 38 conferences and workshops, often with invited talks, and organized 2 conferences. The results had considerable social impact, cumulatively reaching 73 media items, including press, radio and TV interviews.
CADENCE achieved very significant advances over the state of the art, as explained above. Below we highlight their significance:
- A number of novel catalytic structures designed for the TME, often with multifunctional properties (i.e. more than one anticancer action) and/or with selective activation capabilities. Several were encapsulated inside exosomes, giving birth to the first catalytic extracellular vesicles. In particular, a CO-based reduction process allowed in situ synthesis of any type of noble metal nanocatalysts. Related to this development, CADENCE also paved the way for the design of deactivation-resistant catalysts.
- Demonstration of selective delivery of nanoparticle-loaded exosomes to cells in vitro. Also in vivo delivery was achieved, with a lower selectivity that was nevertheless several times higher than reference methods (EPR effect). The therapeutic action was enough to achieve tumor regression in xenografts and even in disseminated (similar to metastatic) tumors.
- First example of heterogeneous-homogeneous catalysis in the TME. A bimetallic nanocatalysts was used to deplete GSH while generating reactive oxidative species to enhance the chemotherapeutic response. Beyond the catalytic results, the conceptual importance of this contribution lies in the fact that, although the catalyst consisted of solid nanoparticles, catalytic GSH oxidation took place homogeneously, through cations released from the nanoparticles.
- Catalytic transamination: a new addition to the limited (only 4) set of reactions employed so far for TME-based catalytic therapy. Transamination needs to be investigated as a powerful anticancer tool: it affects a wide variety of aminoacids and peptides and does not require oxygen, opening up a wealth of opportunities for catalytic therapy.
- A number of novel catalytic structures designed for the TME, often with multifunctional properties (i.e. more than one anticancer action) and/or with selective activation capabilities. Several were encapsulated inside exosomes, giving birth to the first catalytic extracellular vesicles. In particular, a CO-based reduction process allowed in situ synthesis of any type of noble metal nanocatalysts. Related to this development, CADENCE also paved the way for the design of deactivation-resistant catalysts.
- Demonstration of selective delivery of nanoparticle-loaded exosomes to cells in vitro. Also in vivo delivery was achieved, with a lower selectivity that was nevertheless several times higher than reference methods (EPR effect). The therapeutic action was enough to achieve tumor regression in xenografts and even in disseminated (similar to metastatic) tumors.
- First example of heterogeneous-homogeneous catalysis in the TME. A bimetallic nanocatalysts was used to deplete GSH while generating reactive oxidative species to enhance the chemotherapeutic response. Beyond the catalytic results, the conceptual importance of this contribution lies in the fact that, although the catalyst consisted of solid nanoparticles, catalytic GSH oxidation took place homogeneously, through cations released from the nanoparticles.
- Catalytic transamination: a new addition to the limited (only 4) set of reactions employed so far for TME-based catalytic therapy. Transamination needs to be investigated as a powerful anticancer tool: it affects a wide variety of aminoacids and peptides and does not require oxygen, opening up a wealth of opportunities for catalytic therapy.