Nanovectorized Microalgal Extracts to Fight Candida albicans and Cutibacterium acnes Biofilms: Impact of Dual-Species Conditions

Abstract

Biofilm-related infections are a matter of concern especially because of the poor susceptibility of microorganisms to conventional antimicrobial agents. Innovative approaches are needed. The antibiofilm activity of extracts of cyanobacteria Arthrospira platensis, rich in free fatty acids, as well as of extract-loaded copper alginate-based nanocarriers, were studied on single- and dual-species biofilms of Candida albicans and Cutibacterium acnes. Their ability to inhibit the biofilm formation and to eradicate 24 h old biofilms was investigated. Concentrations of each species were evaluated using flow cytometry. Extracts prevented the growth of C. acnes single-species biofilms (inhibition > 75% at 0.2 mg/mL) but failed to inhibit preformed biofilms. Nanovectorised extracts reduced the growth of single-species C. albicans biofilms (inhibition > 43% at 0.2 mg/mL) while free extracts were weakly or not active. Nanovectorised extracts also inhibited preformed C. albicans biofilms by 55% to 77%, whereas the corresponding free extracts were not active. In conclusion, even if the studied nanocarrier systems displayed promising activity, especially against C. albicans, their efficacy against dual-species biofilms was limited. This study highlighted that working in such polymicrobial conditions can give a more objective view of the relevance of antibiofilm strategies by taking into account interspecies interactions that can offer additional protection to microbes.

Obtaining Bioproducts from the Studies of Signals and Interactions between Microalgae and Bacteria

“…The nanocarriers based on copper alginate loaded with extract, were able to inhibit the formation of biofilms from one and two species of Cutibacterium acnes , but did not inhibit preformed biofilms. Nanovectorized extracts reduced the growth of Candida albicans biofilms, as well as preformed biofilms [ 84 ].…”

Cyanobacteria as Natural Therapeutics and Pharmaceutical Potential: Role in Antitumor Activity and as Nanovectors

“…Once encapsulated in nanoparticles, the hydrophobic bioactive compound becomes completely dispersible in water and can therefore be injected intravenously; the drug-loaded nanoparticles will then be able to release the active ingredient. However, only a very few studies have used this strategy with cyanobacterial compounds, which include nanovectorized extracts from Arthrospira platensis with anti-fungal biofilm activity [ 125 ] and the anti-inflammatory protein phycocyanin from Aphanizomenon flosaquae (a freshwater cyanobacteria usually known as AFA Klamath), the delivery of which to the deep skin layers was improved when using propylene glycol-containing nanovesicles [ 126 ]. However, no attempt to nanovectorise a cyanobacterial compound with an anticancer effect has been reported to date and this would merit future research.…”

Microbial Interkingdom Biofilms and the Quest for Novel Therapeutic Strategies

“…The lipid-loaded alginate NPs were successful in inhibiting biofilm growth and disrupting preformed single-species C. albicans biofilms, which was not verified for the free lipid extracts. However, limited efficiency was observed when these NPs were tested in dual-species biofilms [ 140 ].…”