Antifungal and antibiofilm efficacy of cinnamaldehyde-loaded poly(DL-lactide-co-glycolide) (PLGA) nanoparticles against Candida albicans / Eficacia antifúngica y antibiopelícula de nanopartículas de poli(DL-láctido-co-glicólido) (PLGA) cargadas con cinamaldehído contra Candida albicans

Biofilm-associated Candida infections threaten public health and show high mortality. The drugs used in treatment are very limited due to reasons such as toxicity, low efficacy, and drug resistance, and new alternatives are needed. The use of natural products of plant origin in the biofilm management draws attention. CA (cinnamaldehyde, cinnamic aldehyde, or 3-phenyl-2-propenal) is an essential oil component that can also inhibit mold growth and mycotoxin production. However, there are some limitations in its use due to its poor solubility and volatility in water. Recently, the combination of natural components and nanoparticle-based drug delivery systems shows positive results. In this study, the effects of PLGA (poly(DL-lactide-co-glycolide)) nanoparticles arrested with CA (CA-PLGA NPs) on C. albicans planktonic and biofilm forms (prebiofilm and postbiofilm) were investigated. According to the results, the amount of active ingredient loaded in CA-PLGA NPs is much lower than the free CA and a strong antifungal effect was obtained even at this rate. Also, the postbiofilm application is more effective than prebiofilm application. PLGA NPs can also be a useful carrier for other essential oils, and their potential in various antifungal, antibiofilm, and biomedical applications should be investigated.(AU)

Antifungal and antibiofilm efficacy of cinnamaldehyde-loaded poly(DL-lactide-co-glycolide) (PLGA) nanoparticles against Candida albicans.

Biofilm-associated Candida infections threaten public health and show high mortality. The drugs used in treatment are very limited due to reasons such as toxicity, low efficacy, and drug resistance, and new alternatives are needed. The use of natural products of plant origin in the biofilm management draws attention. CA (cinnamaldehyde, cinnamic aldehyde, or 3-phenyl-2-propenal) is an essential oil component that can also inhibit mold growth and mycotoxin production. However, there are some limitations in its use due to its poor solubility and volatility in water. Recently, the combination of natural components and nanoparticle-based drug delivery systems shows positive results. In this study, the effects of PLGA (poly(DL-lactide-co-glycolide)) nanoparticles arrested with CA (CA-PLGA NPs) on C. albicans planktonic and biofilm forms (prebiofilm and postbiofilm) were investigated. According to the results, the amount of active ingredient loaded in CA-PLGA NPs is much lower than the free CA and a strong antifungal effect was obtained even at this rate. Also, the postbiofilm application is more effective than prebiofilm application. PLGA NPs can also be a useful carrier for other essential oils, and their potential in various antifungal, antibiofilm, and biomedical applications should be investigated.

In vitro antibiofilm efficacy of farnesol against Candida species.

Candida species are opportunistic fungi that can cause mucosal or invasive infections. Especially in biofilm-related infections, resistance is very high to anifungals; therefore more effective treatment strategies are needed. Farnesol(3,7,11-trimethyl-2,6,10-dodecatriene-1-ol) is the quorum sensing (QS) signal molecule and can interact with Candida species both as a QS molecule and as an exogenous agent. The aim of this study was to investigate the effects of farnesol on both the planktonic and biofilm forms of Candida species by colorimetric, microbiological, and electron microscopic methods. Obtained results demonstrated the inhibitory effect of farnesol on the planktonic and biofilm forms of Candida. Farnesol showed a biofilm-enhancing effect at lower concentrations. TEM findings showed the membrane and wall damage, vacuolization, or granulation in cells. SEM images confirmed biofilm reduction in pre-/post-biofilm applications as a result of farnesol treatment. In conclusion, farnesol can be used as an alternative agent to reduce the Candida biofilms, with future studies.

Enhanced Bioactive Exopolysaccharide Production by Mossy Maze Polypore, Cerrena unicolor (Higher Basidiomycetes) in Submerged Culture Conditions.

In this study, the culture requirements of the Cerrena unicolor OBCC 5005 strain were determined to optimize bioactive exopolysaccharide production in submerged culture. The effects of initial medium pH, carbon and nitrogen sources, inoculum age and amount, and mineral source on exopolysaccharide and mycelial biomass production by the C. unicolor OBCC 5005 strain were studied using a one-factor-at-a-time method. The highest exopolysaccharide production was obtained when culture parameters were used as initial medium pH: 5.5, 5% sucrose, 5% mycological peptone, and 5% of 4-day inoculants in the presence of 5 mM Fe2+. Optimized culture conditions at a flask scale were applied to a 3-L stirred tank reactor. As a result, 7.92 g/L and 7.34 g/L maximum exopolysaccharide production in optimized conditions at flask and stirred-tank reactor scales were achieved, respectively. The present study is the first to prove that C. unicolor can yield high bioactive exopolysaccharide production at flask and stirred-tank reactor scales.

Microbial transformations of isophorone by Alternaria alternata and Neurospora crassa.

Isophorone (3,5,5-trimethyl-2-cyclohexen-1-one), a monoterpene, and the structurally related 1,8-cineole and camphor, have demonstrated a protective effect against cancer, biological activity against a variety of microorganisms, and anti-oxidant properties. The derivatization of isophorone is, therefore, an important field of xenobiochemistry, pharmacology and toxicology. The aim of this study was to obtain derivatives of isophorone through microbial biotransformation and evaluate the biotransformation metabolites as potential antimicrobial agents. Incubation of isophorone with the fungi Alternaria alternata and Neurospora crassa afforded 4a-hydroxy- and 7-hydroxy-isophorone as transformation metabolites. The antimicrobial activities of isophorone and the metabolites were evaluated in vitro both by using agar dilution and microdilution methods. However, no significant antibacterial activity was observed when compared with those of standard substances.