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.

https://repositorium.sdum.uminho.pt/bitstream/1822/73912/1/document_54581_1.pdf

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

Surfactants are molecules that lower surface or interfacial tension, and thus they are broadly used as detergents, wetting agents, emulsifiers, foaming agents, or dispersants. However, for modern applications, substances that can perform more than one function are desired. In this study we evaluated antioxidant properties of two homological series of N-oxide surfactants: monocephalic 3-(alkanoylamino)propyldimethylamine-N-oxides and dicephalic N,N-bis[3,3′-(dimethylamino)propyl]alkylamide di-N-oxides. Their antiradical properties were tested against stable radicals using electron paramagnetic resonance (EPR) and UV-vis spectroscopy. The experimental investigation was supported by theoretical density functional theory (DFT) and ab initio modeling of the X–H bonds dissociation enthalpies, ionization potentials, and Gibbs free energies for radical scavenging reactions. The evaluation was supplemented with a study of biological activity. We found that the mono- and di-N-oxides are capable of scavenging reactive radicals; however, the dicephalic surfactants are more efficient than their linear analogues.

https://www.mdpi.com/1422-0067/22/15/8040/pdf

Antiradical Properties of N-Oxide Surfactants-Two in One.

The application of microbially derived biosurfactants can be of great benefit in the industrial production of personal care and detergent-based products. Both product categories have common features: dependence of their production on large amounts of synthetic surfactants, widespread daily life usage by the general population worldwide, and unwise disposal, posing significant health and environmental risks. There is a currently increasing demand for more ecocompatible products and safer ingredients, driven by industrial sustainability, environmental awareness, and new regulations. Microbially based biosurfactants offer great benefits in this respect. Additionally, biosurfactants possess a high surface activity and directly associated functional properties and antimicrobial activity of high relevance to the personal care and cleaning industries. This chapter briefly highlights the advantages and functional properties of biosurfactants critical to their application in these industries. It also provides an updated overview of the evolution of biosurfactants in the development of different personal care and detergent-based cleaning products.

Application of biosurfactants in the production of personal care products, and household detergents and industrial and institutional cleaners

Surfactants possess the ability to reduce surface tension at low concentrations, resulting in emulsification, foaming, wetting, and solubilizing. As a versatile industrial material, surfactants can be widely used as additives in the industrial field as different as textile, metal processing, mineral processing, new materials, industrial cleaning, construction, and pharmaceuticals. The most extensive application of surfactants perhaps is in the household and cosmetic industries, such as laundry detergents, dishwashing detergents, facial and body cleansers, and preparation of emulsions and creams. However, the extensive use of detergents, cleaners, and cleansers on skin may cause itching, redness, and dryness termed as surfactant-induced irritation, which is at least, partially due to surfactant penetration into skin. To understand how surfactants penetrate into skin, this review summarizes the penetration models proposed by researchers in the past two decades, including the surfactant monomer penetration model, the surfactant micelle and submicelle penetration model, and the recently proposed surfactant charge density and penetration correlation model that demonstrates the correlation between the surfactant charge density and skin penetration.

Limeng Liu

Papers

Penetration of Surfactants into Skin.