# Biosurfactants' Potential Role in Combating COVID-19 and Similar Future Microbial Threats
## 2 Approaches That Can Use Biosurfactants in Outbreak Prevention and Management
### Therapeutics
#### 2.1.1 Delivery Systems  
Delivery systems are structures to improve the effectiveness of drugs, but challenges such as poor delivery due to dilution by biological fluids and drug precipitation are amongst the main reasons for various failures in drug delivery system designs. Challenges faced when surfactants are used as delivery systems include the stability, packaging and formulations providing proper solubility in lipids, low drug loading capacity and risks of gastrointestinal irritations due to high amounts used [27].  
Biosurfactants can form self-aggregating structures called micelles (Figure 3), which can act as good emulsifiers and have antimicrobial properties useful in the design of drug delivery systems. Biosurfactant-based microemulsion drug delivery systems can be used to make existing therapeutics more effective by either increasing the loading capacity, bioavailability, or provide more control in the release. They can encapsulate and solubilize hydrophobic and hydrophilic drugs in emulsions [25]. Microemulsion drug delivery systems are bio-compatible, thermodynamically stable, and usually highly surface active. Glycolipids and lipoproteins have been commonly used for this purpose and are a potential replacement for contemporary synthetic options [28]. These versatile microemulsion systems are emerging as novel drug delivery systems that can enable the modification of drug formulations for topical, oral, nasal, ocular, intravenous, or other routes of drug administration [25; 27].  
Glycolipid sugar chains can also be used to target specific cells because they can be recognizable by carbohydrate-binding proteins on cell surfaces [29]. Through precise  
Figure 3: **(A)** Biosurfactant molecule, **(B)** Reverse micelle structure, **(C)** Micelle structure.  
modifications, this can be applied in targeting specific cells with intracellular pathogens such as viruses, thereby reducing spread to other less-affected cells. Glycolipid micelles can form structures such as liposomes, gels, niosomes, cubosomes and hexosomes [29] which can serve as a vehicle for the delivery of a drug to a target site while maintaining its integrity and that of the molecule carried in the body fluid environment. In the case of COVID-19, an aerosol formulation containing biosurfactant drug delivery system has been suggested to be a likely mode to deliver drugs, because the virulence is mainly observed in the lungs. In addition to delivery, another advantage is their antiviral activity which can inhibit viruses at the locus of infection [30]. In nanobiotechnology, applications of rhamnoids as microemulsion stabilizers of different nanoparticles in drug delivery systems have also been reported. These include nickel oxide nanoparticles [31; 32] and silver nanoparticles [33; 34; 35; 36]. It is clear that biosurfactant-based drug delivery systems have the potential for better efficiency in drug delivery systems; research has increased around the exploration of the effects on virulent microorganism species that have outbreak potential.