Periodic Reporting for period 2 - POLYTHEA (Design and photo-optimization of Photosensitizer for Human Health and Food security applications or “how light can save lives”) Reporting period: 2020-01-01 to 2022-06-30 Summary of the context and overall objectives of the project The development of active compounds to efficiently fight microbial infections and cancer are of utmost importance for public health. Tetrapyrrolic photosensitizers (PS) are good candidates, as these photo-excitable molecules induce cell death via the formation of reactive oxygen species (ROS) and present very low toxicity in the absence of light. They are already used in photodynamic therapy (PDT) for cancer or skin disease treatments or in photo-antimicrobial chemotherapy (PACT). Unfortunately, research and training in this field is still largely fragmented in Europe. Scientific barriers must be overcome to increase their efficacy by improving the excitation pathways, ROS production, specific cell targeting, Gram (-) bactericidal effect and prevention and/or eradication of biofilms. For this reason, through our 10 Ph.D. thesis we developed: new PS for various types of PDT (anti-cancer, anti-bacterial, anti-inflammatory and immune-activating), improving their photophysical and biological properties; innovative bio-inspired drug carriers or supports. Two of our ESRs obtained a joint diploma, and a multidisciplinary and inter-sectorial training program has been implemented through network events and secondments to non-academic partners. The ultimate objective of the project was to show "How light can save lives", and we believe we did. Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far Work Packages1. The management included a Supervisory Board (SB) and an International Advisory Board. This WP ensured a follow up on administrative, legal and financial aspects, and was in contact with the WP leaders to coordinate the redaction and submission of the deliverables. 2. Recruitment of the ESRs, follow up of the career development plans and co-supervision agreements. Organization of webinars and 4 training schools. The ESRs organized the “HighLIGHTing Science Meeting”. 3. Update of the project website (www.polythea.eu) social media (@POLYTHEA1), data management plan and newsletters. Participation to 94 scientific events. 40 publications in peer-reviewed journals. 4. The synthetic work delivered new PS, alternative functionalization for bioconjugation and carrier systems. Unexpected but highly promising PS systems were obtained, even on a multigram scale during their first training secondment in PorphyChem for 3 ESRs. The syntheses of polymer coatings and other bio sourced matrix have progressed beyond the initial plan.5. The photophysical studies are completed. A guideline on all optimal properties of PS for various applications was written.6. Different formulations were investigated in order to improve PS availability in aqueous media for PACT purpose, as acetylated lignin nanoparticles that work as a universal, cheap and green material for the delivery of porphyrins; 31 novel water-soluble BODIPY scaffolds that show an acceptable range of inhibition activity with production of ROS and microbial inactivation. Concerning anticancer applications, in vitro evaluations against different cell lines were conducted and a series of theragnostic agents, combining arene-ruthenium assemblies and radio-labelling moieties were prepared and evaluated.7. The in vivo visualization experiments with labelled nano systems and in vivo evaluation of some of the PS developed by the consortium have been successful but some were cancelled because of cancelation of the secondments mainly due to COVID-19 outbreak. Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far) Projects1. Design, synthesis, optimization and characterization for improving the two-photon absorption properties of PS for prospective use in PDT, such as encapsulation of a porphyrin PS in acetylated lignin nanoparticles; optimization of the PS Temoporfin® ; design and organic synthesis of new porphyrin-pyrimidine dyads or the expansion of the porphyrin macrocycle using naphthalene and substitution to include heavy elements (thiophene, selenophene, and tellurophene). The nonlinear optical properties of the compound have been evaluated.2. Optimized PSs require the ability to synthetically easily alter and modify the core macrocycle structure, which has been done through development of a modular synthesis of hydroporphyrins. In depth photophysical studies have shown singlet oxygen production and promise for subsequent cell biological studies. 3. New excitation modes of PS: cyanine have been combined with porphyrins to obtain well defined covalent molecular systems that can use NIR light to generate triplet states and RIS. Investigations have been also included into films.4. Development and evaluation of radiolabeled theragnostic agents that could be protected and transported to cancerous cells by functionalized cellulose nanocrystals. A series of in vivo tests have confirmed that such hybrid compounds have the potential of generating new drugs and a potential impact on health care. At least, analogous hybrid systems using similar approaches might be able to reach the market and open up new research perspectives. 5. Insertion/encapsulation of PS in hydrogel from biopolymers, such as hyaluronic acids. Different PS like porphyrins, chlorins and bodipy have been synthetized and antimicrobial evaluation have been done. 6. Ideal PSs must possess certain chemical and photophysical characteristics. In order to develop a core structure amenable to chemical functionalization and bioconjugation a [2+2] MacDonald type condensation strategy for oxidation-resistant gem-dimethyl chlorins has been developed and a small library of compounds was prepared and tested.7. Development of modified lignin nanoparticles and encapsulation of PS in order to investigate their photodynamic effect on planktonic bacteria. Those systems can be loaded with PS and are efficient against Gram-positive strains, very stable vs. time, light and pH. They demonstrated their capabilities to photocatalyze the degradation of highly prescribed antibiotics, allowing an important decrease of the total organic carbon.8. Study of Redaporfin, a synthetic sulphonamide fluorinated bacteriochlorin, has phenyl-macrocyclic single bonds with hindered rotations that generates a different spatial distribution of the sulphonamide groups in the meta positions. We showed that it is possible to separate the four atropisomers of redaporfin, which were tested regarding their uptake and PDT efficacy. In vitro and in vivo immunomodulatory studies showed that utilization of specific atropisomers constitutes a novel drug delivery principle.9. Targeted appropriate PS solubility and the ability to achieve modular formulations through appropriate design criteria. Hydrogels were developed as flexible PS delivery agents. The PS have either been bound covalently in the framework of the gel or as inclusion compounds. Synthetic studies with modified temoporfin as PS and cross-linker within the gel gave a highly promising immunostimulatory PDT formulation as shown in vivo.10. Synthesis and characterization of organometallic-based PS for new PDT applications. The new PS have been tested for the first time on fibroblast-like synoviocytes cells. The in vitro activity was excellent, with IC50 values in the nano-molar range, thus being so far the most active compounds ever tested in such cells. These cells are particularly relevant, as they are linked to rheumatoid arthritis, a disease affecting a large number of the population. The PS appeared to be very promising, a patent application was even envisaged. Related documents Avatar.jpg
