Pharmaceutical applications of microbial biosurfactants

Biosurfactants are becoming more and more popular in biomedical and pharmaceutical applications due to their intriguing biological and physicochemical characteristics. The amphiphilic nature of molecules imparts antimicrobial and antiviral properties, which are largely exploited for their application as therapeutic agents in wound healing, dental health, and infection control, especially against antimicrobial-resistant, multidrug-resistant microbes and viruses such as HIV and herpes simplex virus. The ring-shaped peptide and hydrophobic chain interact with bacterial membranes, inserting into lipid bilayers and destabilising them, leading to pore formation and membrane leakage. Further, BSs disrupt microbial biofilm formation, making them more permeable and susceptible to antibiotics. The anti-adhesive property is exploited to prevent bacterial colonisation on medical implants. The extensive use of biosurfactants as immunomodulators and anti-allergen, anti-tumour action via regulating cell proliferation, differentiation, and apoptosis is extensively discussed, including their use in regulating metabolic disorders. Biosurfactants can self-assemble to form micelles that can encapsulate drugs, improving their solubilisation and stability, and targeted delivery and bioavailability to specific sites of the body. Biosurfactants, when used as adjuvants or in combination with antibiotics or nanoparticles, can have a synergistic effect, enhancing their responses and reducing their toxicity and microbial resistance. In this review, we primarily summarise the pharmaceutical application of biosurfactants using two major classes of biosurfactants: lipopeptides (example: surfactin and iturin A) and glycolipids (example: sophorolipid, rhamnolipid, and mannosylerythritol lipid).