Bacterial infections are one of the major threats to public health, food safety and development which makes it is necessary develop materials and strategies that limit or prevent these bacterial proliferations and biofilm infections.[1] Although, medical implants have led to dramatic improvement in patient's health and well-being, they are accompanied by drawbacks that include surgical risks during placement or removal, implant failure and more specifically microbial infections. These implant-associated infections are mainly caused by the bacterial bio-films in which bacteria are more recalcitrant towards treatments. Indeed, implant surfaces are non-vascularized abiotic materials rendering the common strategies inappropriate and ineffective.[2] In this context we have designed and developed innovative and smart interfaces based on phosphonium self-assembled monolayers (SAMs)  that can be electrically activated on-demand for eradicating bacterial infections on solid surfaces. Hence, upon electroactivation, a successful eradication of gram-positive and gram-negative bacterial strains has been clearly highlighted on SAM-modified titanium surfaces. Subsequently, we observed 95% and 90% antibacterial efficiencies against Staphylococcus aureus and Klebsiella pneumoniae. More importantly, no cytotoxicity has been observed towards eukaryotic cells which clearly demonstrates the biocompatible character of these novel surfaces for further implementation.

Additionally, in our ongoing work, we have explored the synergistic relationship between electrical stimulus for drug delivery and wound healing. Our bodies naturally generate endogenous electrical fields in order to facilitate the migration of fibroblasts, keratinocytes, macrophages, epithelial cells and ions to the wound site to speed up the healing process.[3] In this regard, we have designed and developed electrochemically polymerized polypyrrole films deposited on ITO substrates encapsulated with antimicrobial peptides, which can be released in a controlled manner upon electrical application. Apart from exploring the phenomenon of electrotaxis in wound healing as a consequence of applying an exogenous electrical field, the bioelectric effect is also being studied in depth to understand the mechanisms by which applied electrical fields render the surface antimicrobial. We highlight the advantages of using electrochemical deposition as a technique for film formation as it allows for precise control over film thickness, surface roughness and homogeneity, and can expand the application for these films to not only as electrically responsive wound healing patches, but also as coatings for food packaging and other wearable electronics. These films have been characterized and their properties have been thoroughly studied using various techniques which further support the successful antimicrobial encapsulation throughout its internal framework. Finally, the biocompatible nature of these films supports their potential in various applications.

1.Tacconelli, E.; Carrara, E.; Savoldi, A.; Harbarth, S.; Mendelson, M.; Monnet, D. L.; Pulcini, C.; Kahlmeter, G.; Kluyt-mans, J.; Carmeli, Y.; Ouellette, M.; Out-terson, K.; Patel, J.; Cavaleri, M.; Cox, E. M.; Houchens, C. R.; Grayson, M. L.; Hansen, P.; Singh, N.; Theuretzbacher, U.; Magrini, N. (2018) Lancet Infect. Dis.18, 318-327.

2. Carrara, S.; Rouvier, F.; Auditto, S.; Brunel, F.; Jeanneau, C.; Camplo, M.; Sergent, M.; About, I.; Bolla, J.-M.; Raimundo, J.-M. Int. J. Mol. Sci. 2022, 23, 2183. https://doi.org/10.3390/ijms23042183

3. Farber, P. L., Isoldi, F. C., & Ferreira, L. M. (2021). Electric Factors in Wound Healing. Advances in wound care, 10(8), 461–476. https://doi.org/10.1089/wound.2019.1114