Hydrogel dressings loaded with anticancer/antimicrobial Ag(I) camphorimine complexes for treatment of malignant wounds.

The treatment of skin wounds caused by metastatic lesions is often difficult because not many medicines exist that simultaneously act on cancer cells and bacteria. Such difficulty delays and sometimes compromises the treatment of oncologic patients. To contribute to face that problem a set of silver camphorimine compounds with antibacterial properties were assessed for activity against cancer cells A375 and MeWo melanoma cells using the MTT assay. From them, the silver camphorimine complex 1 displayed the highest combined anticancer and antibacterial activities and therefore was incorporated in a HEMA-based hydrogel to be used in a wound dressing. The hydrogel disks loaded with complex 1 effectively reduced suspensions of E. coli, P. aeruginosa and B. contaminans from the initial 5 × 10 CFU/mL to 0 CFU/mL after 24 and 48 h of incubation. In the case of S. aureus, a reduction of more than 99 % was observed after 24 h. However, after 48 h of incubation, the hydrogel was ineffective towards S. aureus. Although presenting a non-porous structure, the hydrogel revealed to be hydrophilic and able to retain a significant water content, allowing to keep the wound moist. Additionally, it exhibited mechanical and mucoadhesive properties suitable for treatments involving repeated and frequent dressing changes. The hydrogels were loaded with complex 1 by soaking and then sterilized by high hydrostatic pressure (HHP). Biocompatibility studies demonstrated that the loaded dressings were non-irritant and hemocompatible. The sterilization procedure did not affect the integrity of the complex, nor the drug release, which occurred in a sustained way through a non-Fickian diffusion mechanism. The dressing released 618.5 mg/cm/24 h, with nearly 90 % of the release occurring within the first 8 h. Considering the exudate production rates of chronic wounds and the MIC and MBC values for complex 1 it is expected that the dressings will be effective as antibacterial and anticancer agents. In vivo studies will be needed to confirm the clinical potential of the dressings. However, the produced dressings offer a promising approach for both infection control and cancer therapy in chronic wounds.