How is elastin obtained?

Before the advent of biotechnology, the only way to obtain elastin for scientific or cosmetic use was to extract it directly from animal tissues rich in elastic fibers. These tissues, such as the aorta or the skin of cattle and pigs, are major natural sources of tropoelastin – the soluble, immature form of elastin secreted prior to its cross-linking in the extracellular matrix – and elastin. The most commonly used tissues come from fetuses or newborn animals, when elastin synthesis is at its highest. In adult animals, production is low.

Mature elastin being a highly cross-linked and virtually insoluble protein, direct extraction is challenging but remains possible. Once the tissues are obtained—often sourced from slaughterhouses—they are finely minced and incubated in a culture medium containing enzyme inhibitors and antibiotics. After washing and homogenizing the material in an acidic solution, the soluble fractions are isolated by acid extraction followed by a separation step using organic solvents (propanol and butanol). The phase containing elastin is then concentrated, precipitated with acetone, centrifuged, dried, and lyophilized to yield a pure powder. Elastin purity is typically verified by SDS-PAGE electrophoresis and by amino acid analysis.

In addition to traditional mammalian sources, some studies have shown that elastin can also be extracted from fish. In this case, tissues are first analyzed to confirm the presence of elastin and to determine the specific amino acid composition (desmosine and isodesmosine). For commercial production, tissues are thawed, defatted, boiled to remove collagen, then hydrolyzed by proteolytic enzymes. The mixture is filtered and spray-dried to obtain des soluble elastin peptides. The elastin marine is particularly used to formulate dietary supplements.

These techniques currently pose ethical and environmental limitations. That is why the cosmetic and biomedical industries are now turning to more sustainable biotechnological approaches, enabling the production of recombinant elastin without the use of animal tissues.

In light of the ethical and technical limitations of extracting elastin from animal tissues, research has shifted toward more sustainable alternatives: recombinant elastin in the form of peptides. These biopolymers are produced through genetic engineering, most often in bacteria such as Escherichia coli. The objective is to replicate the repetitive sequence of human elastin while avoiding the use of animal tissues. Synthesis begins with designing a gene that encodes elastin to reproduce its sequence. Once the gene is synthesized and inserted into a plasmid—a circular DNA vector—it is introduced into bacteriaE. coli to produce the protein by recombinant overexpression.

After induction with IPTG (isopropyl-β-D-thiogalactopyranoside), a lactose metabolite used in molecular biology, the bacteria begin producing elastin peptides, which are then extracted from the cells. The purification step relies on the thermosensitive properties of these peptides: above a threshold temperature, they become insoluble and precipitate. Purification proceeds as follows:

• Cell lysis and removal of insoluble debrisat a temperature below the threshold temperature.

• Heating the supernatant above the threshold temperature, causing the selective precipitation of elastin peptides.

• Cooling and redissolution of the precipitate in a cold buffer, followed by a further centrifugation to remove impurities.

This method, requiring neither organic solvents nor animal tissues, yields proteins that reproduce the mechanical and hydrating properties of elastin in its natural form, while minimizing environmental impact.

Note : This section, which describes the natural synthesis of elastin in the skin, is intended solely for informational purposes. It does not outline a method used by the cosmetics industry to produce elastin.

Elastin fibers form a complex network in the dermis, the intermediate layer of the skin. The synthesis of elastic fibers, or elastogenesis, is a highly organized process that depends on the availability of the assembly and cross-linking of tropoelastin, the precursor of elastin. Fibroblasts, which also produce collagen and of hyaluronic acid, are the cells that secrete tropoelastin. This molecule is then oxidized by enzymes from the lysyl oxidase family and subsequently cross-linked to form stable bundles. With the help of the glycoprotein fibulin-5, these tropoelastin bundles are deposited onto microfibrils that act as a scaffold, eventually forming a functional elastin fiber.

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• CHILKOTI A. & al. Elastin-like polypeptides for biomedical applications. Annual Review of Biomedical Engineering (2020).

• CHOLI-PAPADOPOULOU T. & al. De novo synthesis of elastin-like polypeptides (ELPs): An applied overview on the current experimental techniques. ACS Biomaterials Science & Engineering (2021).

• DANIELS R. & al. Clinical relevance of elastin in the structure and function of skin. Aesthetic Surgery Journal Open Forum (2021).