Experimental design-based optimization of bioactive coatings for sustainable antimicrobial applications

The uncontrolled spread of infectious diseases has driven the development of innovative materials designed to control microbial transmission and combat harmful pathogens. In this context, inorganic materials have emerged as promising candidates for bioactive coatings, offering intrinsic antimicrobial properties, biocompatibility, and potential eco-friendly applications. However, in accordance with the atom economy and safety criteria outlined by the Green Chemistry Principles, it is essential to ensure the use of the minimal effective dose of antimicrobial agents. This approach minimizes potential toxic effects while optimizing antimicrobial action. Chemometric tools have proven invaluable in designing and refining experimental protocols to achieve these objectives.

This communication proposes innovative strategies for synthesizing and characterizing bioactive coatings based on nanostructured and hybrid inorganic materials. Specifically, two cases of study are presented, focusing on zinc oxide and silver phosphate nanostructures. These materials were synthesized using green electrochemical and precipitation methods and subsequently embedded in polymeric matrices, such as polyvinyl alcohol (PVA), to develop bioactive films via self-standing procedures. Special emphasis was placed on optimizing experimental parameters through chemometric tools.

The chemometric approach enabled the development of materials with reproducible and tuneable properties, ensuring a synthetic yield exceeding 85%. Comprehensive analytical characterization—including electron microscopy, spectroscopy techniques, and solubility studies—was performed to establish correlations between synthesis conditions, material properties, and their potential applications. The antimicrobial structures have nano- and microscale dimensions, and the composite films ensure a controlled release of the metal ions over time.

The findings highlight the potential of these bioactive coatings for industrial-scale production, addressing critical challenges in antimicrobial resistance and promoting sustainable material development.

M.I. acknowledges the financial support from the ERC SEEDS UNIBA programme, project H93C23000660001, “REAL - More for less: REthinking AntimicrobiaL materials”. A.V.M. acknowledges funding by the European Union –NEXTGENERATIONEU – NRRP MISSION 4, COMPONENT 1.