The accelerating prevalence of antimicrobial resistance is challenge the global healthcare system (1). The overuse and misuse of antibiotics have resulted in multi-drug resistance pathogens leading the world to a pre-antibiotic era (2,3). To tackle severe infections, novel therapeutics as well as novel delivery systems are needed. Hence, the objective of this work is to develop an innovative drug delivery vehicle able to tackle multidrug-resistant bacterial infections. We have created novel cross-linked lysozyme composite crystals containing metal nanoparticles (MNPs), i.e. silver or gold. These protein crystals will behave as delivery vehicles able to tackle infections by their chemical composition (lysozyme and nanoparticles) and by the rate of release at which these two components are liberated in the affected area. The rate of release would be controlled by the crosslinking degree of the crystals. We anticipate that these synergistic antimicrobial particles can be an excellent strategy to combat biofilms formation. To obtain this material we followed a bottom-up protocol in which MNPs were firstly obtained in a gelled that was subsequently used as crystallization media to obtaining lysozyme (Lzm) crystals. crystals were later crosslinked at different degrees to control their dissolution rate. Herein, we present a proof of concept of a novel active compounds delivery vehicle in which the vehicle and their cargo has an active and remedial role. This strategy can be easily extended to other proteins and cargos to treat other diseases, to protect goods, etc.

8th International School of Biological Crystallization, ISBC2023. In Granada, 21-26 May 2023