Periodic Reporting for period 1 - PePiPOM (Peptide-functionalized POMs as biofilm disruption agents: searching for synergy in bactericidal materials)
Reporting period: 2019-06-01 to 2021-05-31
One strategy to overcome AMR is the design of new drugs to which the microorganisms would not be resistant anymore. Another strategy involves the production of new coating materials with antimicrobial properties. Bacteria, one of the types of microorganisms presenting drugs resistance, form matrix structures called biofilms as a mechanism of protection and growth strategy. Biofilms provide a highly protective environment to bacteria against exogenous compounds such as antibiotics thus making them highly resistant to conventional therapies; therefore, an approach to inhibit biofilm growth will be of interest in the development of new antibacterial drugs and materials.
PePiPOM presents a strategy combining polyoxometalates (POMs) and peptides, creating a synergy between the antimicrobial activity and amyloid-inhibiting activity of POMs and the biofilm targeting capability of peptides. The main goal of the PePiPOM proposal was the development of new POM-hybrids that prevent biofilm formation by combining both anti-amyloid aggregation and antibacterial activity. To reach this main goal, the project was presented with specific objectives:
I. Development of a new class of POM-peptide hybrids
II. Evaluation of the antibacterial and biofilm inhibition activities
III. In situ evaluation of PePiPOMs on real surfaces
Another goal of this MSCA Individual Fellowship is to foster the development of the individual researcher by a positive impact on her career.
The overall conclusions are:
1) How POMs and peptides interact matters: Different types of POM-peptide hybrids have been studied, differentiated by the mode of interaction between the components: ionic, covalent or metal-coordination. Their further self-assembly should also be taken into consideration. The results from their antibacterial evaluation serving as feedback for the improvement of their design. The combination of POMs and peptides into new materials shows synergistic activity.
2) How bacteria are being attacked is key: the antibacterial mechanism of action of these hybrids is being studied in detail. It is important to finely tune the ability of the new materials to induce reactive oxygen species as well as their biofilm inhibitory capacity, for effective antimicrobial treatment.
3) New targets for innovative treatments: the research of new targets within pathogenic bacteria could mean an impact on the development of new treatments to fight AMR.
(a) Synthesis & characterisation of a new class of POM-hybrids (WP1)
(b) Evaluation of the in vitro anti-aggregation and antibacterial activities of the PePiPOMs (WP2)
(c) Direct linking of peptides to POM anions (WP3)
(d) In situ evaluation of PePiPOMs on real surfaces (plastic and metal) (WP4)
Since the beginning of the action, work has been performed on both design and preparation of new POM-peptide hybrids (by different approaches) and the study of their antibacterial and antibiofilm activities and the research of their mechanism of action.
The hybrids have been characterized by common spectroscopic techniques (NMR, IR, UV-vis, EPR), by TGA, MS and electron microscopies. For the antibacterial assays, model non-pathogenic bacteria strains have been used: E. coli, B. subtilis, S. epidermidis, P. fluorescens. The researcher has been trained in microbiology culture and research. Detailed studies of the mechanism of action of the hybrids are being carried out with promising results which will set a milestone for this project and for the field of POM hybrids and other inorganic-hybrid materials with antimicrobial properties.
In addition, the researcher contributed to antimicrobial assays of other series of compounds, resulting in two publications: molecules and pharmaceuticals.
Exploitation and dissemination:
This project has not produced results suitable for commercial exploitation. The action and some of its results have been presented at the XVI Symposium of Young Researcher in Chemistry (JIQ 2019, Valencia, Spain), at the ACS Spring 2021 meeting (online) and at the Spanish Conference on Biomedical Applications (SBAN 2021, online). We are currently preparing manuscripts describing the antimicrobial activity and mechanism of action of POM-peptide hybrids and other inorganic molecules, as well as a critical review on the topic.
Besides the scientific achievements, an outreach Project has been developed: Bacterfield, a board game that aims at teaching basic concepts of microbiology and raising awareness on antimicrobial resistance to the public of all ages. Bacterfield has gained attention from media and it is being actively diffused in social media as well, and by different activities and events.