Going green: Microbial glycolipids to replace synthetic surfactants for skincare

01 Dec 2022 --- Researchers from Ulster University find that natural surfactants like microbial glycolipids could provide a safer and more suitable option to sodium lauryl ether sulfate (SLES) in skincare applications. They are highlighting a current market demand to replace synthetic ingredients in cosmetics and personal skincare formulations with naturally derived and biocompatible alternatives generated from sustainable resources.

To support the same, they compared the effects of highly purified SL (acidic and lactonic), RL (mono-RL and di-RL) congeners and SLES on a spontaneously transformed human keratinocyte cell line (HaCaT cells) to assess glycolipids’ safety for potential skincare applications.

“Although further studies would be required, [the study results] demonstrate that as potential innocuous and bioactive compounds, microbial glycolipids could provide a substitute to synthetic surfactants in skincare formulations and perform immunopharmacological roles in topical skin infections such as psoriasis,” the researchers note.

Surfactants such as SLES can form up to 50% of the skincare formulation and play a role in emulsification, gelling and micro-encapsulation. Synthetically derived surfactants are less biodegradable than biologically derived alternatives and possess the potential to cause allergic reactions, skin irritations and dysbiosis in the skin microbiome when they come into direct contact with the human skin.

Biosurfactants are naturally derived surfactants produced as secondary metabolites by bacteria, yeast and filamentous fungi.“This is the first time such a comprehensive study on glycolipid safety assessment and potential benefits to the human skin has been carried out,” the researchers state.

Cytotoxicity of microbial biosurfactants
Cytotoxicity is characterized by adverse effects on cells caused by treatment agents post-exposure at a known concentration within a specified time.

Biosurfactants are naturally derived surfactants produced as secondary metabolites by bacteria, yeast and filamentous fungi. Glycolipids constitute the most extensively studied and biotechnologically promising class of biosurfactants.

“The potential advantages of utilizing glycolipids over synthetic surfactants such as SLES in cosmetics and personal skincare formulation are low toxicity, biodegradability and increased compatibility with the human skin,” the study reports.

“Using a combination of in-vitro cell culture, molecular biology techniques and immune assays, we have demonstrated that the purified microbial glycolipid congeners have differing effects on human keratinocytes depending on their chemical structure.”

Compared with SLES, some glycolipid congeners demonstrated negligible effects on cell viability, cell morphology, the production of pro-inflammatory cytokines and the expression of their related genes.

Personal care developments
Recently, Locus Performance Ingredients, a green technology company, created two lines of innovative sophorolipid biosurfactants that have been REACH (registration, evaluation and authorization of chemicals) registered with the European Chemicals Agency.Synthetically derived surfactants are less biodegradable than biologically derived alternatives and possess the potential to cause allergic reactions.

The registrations give EU formulators access to multifunctional biosurfactant ingredients and improve products’ performance and environmental sustainability.

Meanwhile, a new range of renewable and biodegradable surfactants, known as NextLab linear alkylbenzene, was bought by Unilever to be used in the production of linear alkylbenzene sulfonate, used in many of the company’s brands, including Persil, Cif and Sunlight. The surfactant was developed by a Spanish chemicals company named Cepsa Química.

“Using a mass balance approach allows us to start transitioning from black carbon sources to renewable alternatives that offer the same quality cleaning that our consumers expect and love in our brands,” said Kirsten Tosin, Unilever’s head of procurement, home care.

Additionally, Solvay introduced two biosurfactants, Mirasoft SL L60 and Mirasoft SL A60, touted to be 100% biobased, biodegradable and manufactured through a cost-efficient fermentation process to be applied in cosmetics.

“This product launch underlines our commitment to surfactants technology and our long-term vision for the future,” Jean-Guy Le Helloco, global VP of home and personal care at Solvay, emphasized. “We focus on future technology shifts to enable our customers to reach their [environmental] sustainability goals.”

Edited by Radhika Sikaria