Bountiful biopolymers: Biodegradable solutions and trends in personal care formulations

17 Jul 2023 --- Eco-friendly, biodegradable and environmentally safe solutions go beyond consumer demand and are a global need in mitigating harms caused by petrochemical pollutants. Personal Care Insights speaks to International Flavors & Fragrances (IFF) about its biotechnology-driven sourcing of novel ingredients while outlining protein biopolymers and polysaccharides that have been in the industry’s spotlight.

“Biodegradable innovation is important and should be taken seriously by the beauty industry. With the European Green Deal, biobased and biodegradable materials are recognized as a key solution for enabling a sustainable future,” says Johan Jansen-Storbacka, director of personal care at IFF.

“Future opportunities lie with companies and innovators that use new platforms, natural or inspired by nature, to improve performance. Innovations in natural materials are emerging to address this challenge, with greater performance and design flexibility.”

Furthermore, “significant advances” in biopolymers have been noted by Brazil-based researchers, with new applications in the form of coatings, hydrogels, nanocarriers and dermal fillers – some with antioxidant properties – expected to rise.

“As biotechnology advances toward novel methods of obtaining biopolymers or modifying the performance of these materials, new possibilities will surely appear for building platforms that will deliver labile but active cosmetic molecules such as peptides, miRNAs and UV-filters,” write the authors.

“Biopolymers for cosmetics derived from relatively new natural sources may appear in future marketing trends that demand well-defined efficacy and safety aspects.”

Biopolymer functions and applications
According to the Brazil-based study, biopolymers are “obtained by chemically modifying natural biological substances or producing them through biotechnological processes. They are biodegradable, biocompatible and non-toxic.”

Biopolymers are used in various cosmetics functioning as rheological modifiers, emulsifiers, film-formers, moisturizers, hydrators, antimicrobials, and, more recently, materials with metabolic activity on the skin. (Image Credit: Study).

“Polysaccharide-based proteins have been included in conventional formulations as emulsifiers, viscosity modifiers, film-forming agents and foam stabilizers, among other functions,” find the researchers.

“In the nano era, the development of new carriers of, or modifications to, native biopolymers has produced materials with better performance in improving the stability of active molecules or formulations, enhancing sensory features, and providing technological and/or marketing advantages in cosmetics markets.” 

Readily vs. inherently biodegradable
Jansen-Storbacka emphasizes that it is vital for companies to know what biodegradability means, as “having clear definitions and standards will help spur innovation in this field.”

Readily biodegradable is calculated by totaling the percentage of the ingredients following OECD (301-series or 310) or equivalent guidelines for screening, achieving at least 60-70% biodegradation within 28 days. 

While inherently biodegradable must also pass the 60% or 70% biodegradation test, however, the 28 day length can extend up to 60 days.

“Based on the above definition, many products of natural origin are biodegradable. Some popular natural biodegradable solutions are starch, xanthan, guar and alginates, commonly used as thickening agents,” shares Jansen-Storbacka.

“However, when these are functionalized to provide specific or improved performance, their biodegradability is often impacted negatively. Cationic guar is a good example, depending on how much it has been functionalized.”

Biopolymer technology and efficacy
IFF’s Aurist AGC is spotlighted as a readily biodegradable hair conditioning biopolymer developed by the supplier’s proprietary Designed Enzymatic Biopolymer (DEB) technology.

“DEB technology is an enzymatic polymerization of glucose from sucrose with controlled morphology and structure, giving rise to novel ingredients specifically designed to deliver meaningful sustainability benefits with performance comparable or superior to fossil-based ingredients,” explains Jansen-Storbacka.

The technology brings three essential benefits to biopolymers: customizability, structural uniformity and can be designed to be biodegradable.

In a previous interview Jansén-Storbacka alongside Piera Mattia Pericu, market segment leaders of personal care, elucidated the importance of replacing petrochemicals with biodegradable alternatives that perform well and are efficacious.

“Market research has consistently shown that efficacy is non-negotiable. For customers and consumers alike, performance will be key to repeat purchases. Without achieving the performance expected by consumers, biodegradable and bio-based alternatives will not be able to fully replace incumbent materials nor satisfy the customer and consumers’ needs,” notes Jansén-Storbacka.IFF’s Aurist AGC is spotlighted as a readily biodegradable hair conditioning biopolymer.

Protein biopolymer: Silk for wound healing
The Brazil-based study spotlights Silk as a commonly used biopolymer. It is a natural protein fiber with 70-80% fibroin and 20-30% sericin.

Using silk in cosmetics depends on the molecular weight of its peptides, where low-weight peptides are used in hair care and high-weight peptides are used as biomedical materials, hydrogels and bio-membranes.

“It has been reported that silk fibroin stimulates collagen biosynthesis, re-epithelialization and wound healing processes, so it is a suitable candidate for atopic dermatitis or scar elimination treatments,” highlight the researchers. 

“Reports on silk sericin indicate that it is employed in the cosmetics industry as a moisturizer, component of hair products and anti-aging agent.”

Protein biopolymer: Keratin for repair
Keratin refers to a protein family that is the major component of hair, nails, feathers, wool, scales, beaks, claws and horns. 

This biopolymer is used to recover damaged hair in products such as shampoos, conditioners and lotions. “Nourishing, keratin and keratin hydrolysates are ingredients in skin care formulations due to their moisturizing effect,” share the researchers.

“Keratin hydrolysates have been reported to reduce surface tension and emulsifier concentrations, thus minimizing the irritation effects of some surfactants.”

Protein biopolymer: Elastin and collagen
Elastin is a protein component of the extracellular matrix in numerous tissues that require elasticity to perform their functions. “Elastin for cosmetic use may be Type 1 if it is derived from bovine neck ligaments, skin, aorta and related tissues, or Type 2 when derived from cartilage,” explain the authors.  

“Standard cosmetic formulations with elastin include products for skin (creams, serums, masks) and hair care (shampoos, treatments). New trends in elastin applications in cosmetic products involve elastin-derived peptides that improve the elasticity and firmness of the skin, prevent aging, and stimulate skin fibroblasts.”

Similarly, collagen is abundant in extracellular matrix proteins, and native collagen is extracted from animal sources. The authors observe that trends in cosmetics, including collagen, consist of “hydrolysates of the protein” for rejuvenating treatments such as serums, masks and fillers.

“Native collagen cannot penetrate the skin’s stratum corneum, so it remains on the epidermis, but low molecular weight hydrolysates in topical applications can penetrate the skin, accumulate or retain water and help form a new collagen biomatrix,” write the researchers.

“Hydrolyzed collagen can penetrate the epidermis to some extent and act as a water-binding agent, but it cannot replace collagen lost from the skin.”

Polysaccharides from waters
Polysaccharides are derived from biopolymers and are used for its biodegradability, biocompatibility, low  toxicity and relatively low cost, share the authors.

Carrageenan is spotlighted as a polysaccharide extracted from red seaweed, providing high hydrophilicity, mechanical strength, biocompatibility and biodegradability. Its main uses in cosmetics are thickening and stabilizing, as a gelling agent and as a binder.(Image Credit: Study).

Another polysaccharide is sodium alginate, a water-soluble polysaccharide derived from brown algae. “Chemical modifications of alginates can serve two purposes: enhance existing properties or produce novel ones,” note the authors.

“Traditional uses of alginate include gelling, binding, thickening agent, moisturizer, emulsion stabilizer and bioactive substance. It is well known for its moisturizing effect in hydrogels, face masks and other gums and extracts from natural products.”

Trends in sodium alginate applications include using it as a carrier of actives as micro- and nanoparticles. “It is a single-step approach with excellent control of the particle size and yield that needs a low amount of solvents. Long processing times could be the only disadvantage.”

Polysaccharides: Xanthan gum and starch
The researchers explain: “Xanthan gum is a microbial polysaccharide, often employed in the cosmetics industry due to its high electric potential. It has stabilizing properties and is used with various ingredients of cosmetic formulations due to its thickening capacity at low concentrations.”

“This gum has greater thermal stability than other polysaccharides, so heat applications do not affect viscosity.”

Furthermore, the second-most commonly produced natural biopolymer globally behind cellulose is starch, a storage polysaccharide in vegetables. Modified starch provides moisturizing, softening and hydrating skin benefits.

“Native starch is rarely used in the cosmetics industry because it is insoluble and not easily incorporated into formulations (e.g., emulsions). Modified starch, however, is used as an ingredient in cosmetic formulations,” flag the authors.

“Starch can be modified by physical, chemical or enzymatic processes. Numerous modified starches can be used in water-free cosmetics, tablets, emulsions, lotions, toothpaste and creams. The modified starch most often used in cosmetics is an esterified form, especially octenyl succinic anhydride, which many cosmetics formulators prefer.”

It is used in water-free cosmetics, such as solid shampoos and compact powders. Also, modified starch is used for waterless, micro- and nano-sized structures that protect and control the release of components added to emulsions, share the authors.

Polysaccharides: Chitosan and hyaluronic acid
Chitosan is found in fish scales, arthropod exoskeletons and as a structural element in fungi and yeast cell walls. Jansen-Storbacka emphasizes the difference between readily biodegradable and inherently biodegradable.

“It is often used as a powerful hydrating and humectant agent in skin care due to its cationic behavior. It can interact with negative charges on the skin surface, deposit moisture in the skin and even reduce transdermal water loss due to its ability to form films that act as barriers,” write the authors. 

“A novel class of chitosan derivatives that has gained interest contains chitosan oligosaccharides (COS). These consist of 2-10 β-1,4-linked D-glucosamine units with special biological activities.”

The researchers note that a separate study showed that topical application of COS prevented UV-induced skin aging, wrinkle formation and skin collagen degradation due to its antioxidative and anti-inflammatory properties.

“Chitosan is being used increasingly in nanosystems to form carriers (i.e., micro and nanoparticles) for active components in cosmetics applied to the skin, for example, UV filters, retinol, antioxidants and essential oils,” write the authors.

The ever-popular hyaluronic acid, another example of a growingly popular polysaccharide, retains water 1,000 times its weight in water. It is sourced by fermentation of bacteria (e.g., hemolytic group C Streptococcus, especially S. equi) or “from the vitreous and umbilical cord cockscomb of animals.”

The latter is preferred for process efficiency, high molecular weight and non-inflammatory properties. In contrast, microbial fermentation poses a lower risk of cross-infection, no raw material restrictions, potential for scaling-up, low cost, high quality and environmental friendliness, according to the researchers.

The anti-aging hyaluronic acid is used widely in gels, creams, emulates, films, scaffolds, serums, filler injections, dermal fillers, facial fillers, autologous fat gels, lotions, implants, tablets and capsules.

By Venya Patel