Microspheres based on galactomannan and Spondias purpurea L. extract to increase antifungal and antibiofilm efficacy against Candida spp.

The ongoing problem of an increasing resistance of Candida spp. to available antifungals, has made it necessary the search for new therapeutic alternatives. The aim of this work was to develop a microsphere based on Caesalpinia ferrea galactomannan and Spondias purpurea L. stem bark extract using the spray drying technique and evaluate its antimicrobial effect on biofilm formation and planktonic cells of Candida spp. Differential scanning calorimetry (DSC), infrared analysis (IR) and scanning electron microscopy (SEM) were used to characterize the microsphere, in addition to the encapsulation efficiency by HPLC to quantify the extract in the microsphere. In microbiological analyses, broth microdilution and antibiofilm tests were carried out. The results of the minimum inhibitory concentration (MIC) for the stem bark extract (SBE) were within 0.5-2 μg mL-1 and the galactomannan microsphere (GMB) 1-8 μg mL-1. As for the biofilm, the microsphere compared to the extract showed a statistically significant improvement at 8xMIC for C. albicans 1, while for C. auris, it was at 4xMIC and 8xMIC. Furthermore, SBE and GMB did not present toxicity. The study revealed that the synthesized microspheres have the potential to be used as an antifungal agent.