Biosurfactants: Properties and Applications in Drug Delivery, Biotechnology and Ecotoxicology

Abstract

Surfactants are amphiphilic compounds having hydrophilic and hydrophobic moieties in their structure. They can be of synthetic or of microbial origin, obtained respectively from chemical synthesis or from microorganisms’ activity. A new generation of ecofriendly surfactant molecules or biobased surfactants is increasingly growing, attributed to their versatility of applications. Surfactants can be used as drug delivery systems for a range of molecules given their capacity to create micelles which can promote the encapsulation of bioactives of pharmaceutical interest; besides, these assemblies can also show antimicrobial properties. The advantages of biosurfactants include their high biodegradability profile, low risk of toxicity, production from renewable sources, functionality under extreme pH and temperature conditions, and long-term physicochemical stability. The application potential of these types of polymers is related to their properties enabling them to be processed by emulsification, separation, solubilization, surface (interfacial) tension, and adsorption for the production of a range of drug delivery systems. Biosurfactants have been employed as a drug delivery system to improve the bioavailability of a good number of drugs that exhibit low aqueous solubility. The great potential of these molecules is related to their auto assembly and emulsification capacity. Biosurfactants produced from bacteria are of particular interest due to their antibacterial, antifungal, and antiviral properties with therapeutic and biomedical potential. In this review, we discuss recent advances and perspectives of biosurfactants with antimicrobial properties and how they can be used as structures to develop semisolid hydrogels for drug delivery, in environmental bioremediation, in biotechnology for the reduction of production costs and also their ecotoxicological impact as pesticide alternative.

Skin Cleansing without or with Compromise: Soaps and Syndets

“…The key points of difference between soaps and syndets ( Figure 1 ) include the following: their historical perspective of discovery and use [ 19 , 29 ] (see Section 2.1.1 ); chemistry [ 9 , 16 , 24 , 29 ] (see Section 2.1.2 ); ingredient composition and general formulation [ 3 , 17 , 25 ] (see Section 2.1.3 ); pH (see Section 2.1.4 ) [ 22 , 24 , 25 ]; surfactant characteristics [ 13 , 21 , 32 ], cleansing capacity [ 13 , 16 , 21 , 27 , 32 , 33 ] and antimicrobial activity [ 23 , 28 ] (see Section 2.1.5 ); mildness [ 13 , 16 , 21 , 27 ] (see Section 2.1.6 ); sustainable sourcing of surfactants and their environmental impact [ 26 , 30 , 34 , 35 , 36 ] (see Section 2.1.7 ); and interaction with the skin [ 3 ], associated benefits and negative effects [ 3 , 9 , 10 , 20 , 25 ] (see…”

“…Nowadays, a rise in product demand and environmental awareness is driving the development of a new generation of sustainable and environmentally friendly surfactants, including biosurfactants (green surfactants) of plant [ 36 ] (see Section Biosurfactants of Plant Origin) and microbial [ 35 , 36 , 61 ] (see Section Biosurfactants of Microbial Origin) origin and amino acid-based surfactants [ 34 , 62 ] (see Section Amino Acid-based Surfactants). When compared to conventional surfactants found in soaps and syndets, the main advantages of these novel surfactants include their high biodegradability profile, creating less hazardous waste, renewability, low risk of toxicity, functionality under extreme conditions (e.g., temperature and pH), and long-term physicochemical stability [ 35 ]. Such properties allow these surfactants to be used across various industries (e.g., food, cosmetic and pharmaceutical) in a range of processes (e.g., emulsification, separation) to reduce surface tension and to promote the penetration of bioactives through biological membranes [ 34 , 35 , 36 , 63 ].…”

“…When compared to conventional surfactants found in soaps and syndets, the main advantages of these novel surfactants include their high biodegradability profile, creating less hazardous waste, renewability, low risk of toxicity, functionality under extreme conditions (e.g., temperature and pH), and long-term physicochemical stability [ 35 ]. Such properties allow these surfactants to be used across various industries (e.g., food, cosmetic and pharmaceutical) in a range of processes (e.g., emulsification, separation) to reduce surface tension and to promote the penetration of bioactives through biological membranes [ 34 , 35 , 36 , 63 ].…”

“…The hydrophilic portion of a microbial biosurfactant can be composed of a carbohydrate, amino acid, cyclic peptide, phosphate, carboxylic acid, or alcohol, while the hydrophobic portion can be composed of long-chain fatty acids or hydroxylated fatty acids. A variety of microorganisms, including bacteria (e.g., Bacillus subtilis , Pseudomonas aeruginosa ), yeasts (e.g., Candida lipolytica , Candida bombicola ) and filamentous fungi (e.g., Phoma herbarum ), can effectively produce biosurfactants with different molecular structures and surface activities [ 35 , 36 , 67 ].…”

Phase Behaviour, Functionality, and Physicochemical Characteristics of Glycolipid Surfactants of Microbial Origin

“…About 30-50% of the total cost comes solely from the preparation of culture medium for biosurfactant production secreted by microorganisms (Ebadipour et al, 2016). Thus, current research challenges include a decrease in the cost of raw materials, consumables, utilities, labor, and waste treatment and disposal (Bjerk et al, 2021). In terms of price, synthetic surfactants (priced at approximately USD 2/kg) (Kosaric and Vardar-Sukan 2015), are much cheaper compared to the pure rhamnolipids (priced range between USD 1250/kg and USD 2500/kg) (www.agaetech.…”