Curcumin (CUR) is a natural substance extracted from turmeric that has antimicrobial properties. Due to its ability to absorb light in the blue spectrum, CUR is also used as a photosensitizer (PS) in antimicrobial Photodynamic Therapy (aPDT). However, CUR is hydrophobic, unstable in solutions, and has low bioavailability, which hinders its clinical use. To circumvent these drawbacks, drug delivery systems (DDSs) have been used. In this review, we summarize the DDSs used to carry CUR and their antimicrobial effect against viruses, bacteria, and fungi, including drug-resistant strains and emergent pathogens such as SARS-CoV-2. The reviewed DDSs include colloidal (micelles, liposomes, nanoemulsions, cyclodextrins, chitosan, and other polymeric nanoparticles), metallic, and mesoporous particles, as well as graphene, quantum dots, and hybrid nanosystems such as films and hydrogels. Free (non-encapsulated) CUR and CUR loaded in DDSs have a broad-spectrum antimicrobial action when used alone or as a PS in aPDT. They also show low cytotoxicity, in vivo biocompatibility, and improved wound healing. Although there are several in vitro and some in vivo investigations describing the nanotechnological aspects and the potential antimicrobial application of CUR-loaded DDSs, clinical trials are not reported and further studies should translate this evidence to the clinical scenarios of infections.

Denture stomatitis is a common infection in denture wearers. This study evaluated the recovery of Candida spp. from the palate of Wistar rats after using an acrylic device with single and mixed-species of Candida spp. After approval of the Ethics Committee, 84 male and female Wistar rats were used. Custom-made acrylic devices were fabricated for each animal and sterilized by microwave irradiation. Single and mixed species biofilms of C. albicans (Ca), C. glabrata (Cg), and C. tropicalis (Ct) were grown on the devices for 48 h at 37°C. Rats were anesthetized and the devices were cemented on the molar teeth (n=5 for each sex and Candida spp.). Rats received a carbohydrate-rich diet. Single and mixed species were inoculated in the oral cavity thrice after three-day intervals. Controls received only dentures without Candida spp. After 4 weeks, the devices were removed, the palates were swabbed, and diluted samples were plated on Agar Sabouraud Dextrose and CHROMAgar Candida for colony counting and presumptive identification, respectively, after 48 h. Data were analyzed by 3way ANOVA (α=5%). There was a significant interaction (p=0.003) between sex and species. For females, all groups recovered significant values (p≤0.027) compared with controls. For males, groups with Ct as single and dual-species showed the lowest values without difference (p≥0.183) with the control. The groups with triple-species showed the highest values but without difference (p≥0.071) with the groups with single and dual-species, except males with Ct. Ct alone showed reduced recovery from palate of male rats.