To date, 28 different collagens have been described, each of which is named using Roman numerals (I–XXVIII). These are classified according to the combination of three (out of a possible 46) polypeptide chains - called α chains - that make up their structure. For example, collagen I is a heterotrimer comprised of two α1(I) chains and one α2(I) chain, while collagen II is a homotrimer made up of three α1(II) chains. The different collagen family members vary considerably in terms of tissue distribution, expression level, and the role they perform.
The five most common types are:
It’s important to choose the correct type of collagen for your research or application. All collagens share a common structural feature known as a triple helix, which forms as the α chains twist around one another. The triple helical sequence is made up of Gly-X-Y repeats, where X and Y are frequently proline and hydroxyproline respectively; mutations in the collagen triple-helix domain are associated with a growing number of human disorders. Collagens can be further categorised into subfamilies according to the supramolecular assemblies they form; these are referred to as fibrils, beaded filaments, anchoring fibrils, and networks, and they differ with regards to abundance and function.
Collagen is derived from many different sources and it is important to understand what the implications are for your research/application.
For decades, cows have been the prime industrial source of collagen. Plentiful, manageable and easy to breed, the animal’s collagen products have transformed reconstructive surgery and, as a culturing bio-material, advanced global medical research. Collagen types I, II and IV can be sourced from the animal’s Achilles tendon, nasal cartilage and placental villi, respectively. But bovine collagen’s successful status has not come without criticism. As a fellow mammal, cows can transfer multiple diseases to humans that non-mammalian sources cannot.
And as outbreaks of transmissible spongiform encephalopathies (TSEs) and foot and mouth disease (FMD) continue to be reported in bovine collagen producing countries. Consequently, many researchers are looking for safer alternatives. Aside from the disease risk, it has been estimated that approximately nearly 3% of the population experience allergic reactions to bovine collagen. When the environmental sustainability of the meat industry is also taken into consideration, it is easy to understand why many lab professionals are turning their backs on bovine sources.
Unlike cow-sourced collagen, porcine proteins do not cause a significant allergic response in humans, perhaps owing to a closer homology to human collagen. Thus, the dermis and small intestinal mucosa of pigs have been widely used for biomaterial, tissue repair and cosmetic purposes. But, just like bovine collagen, porcine sources also come with a risk of disease and contamination. As a mammalian relative, the bacterial and viral pathogens of pigs are often transferable to humans, as most infamously demonstrated during the Swine Flu pandemic of 2009-10.
As a pig product, porcine collagen is a prohibited substance for the nearly two billion people who follow certain religious orthodoxies. And, just like bovine products, pig derived collagen is sourced from a relatively complex organism that can have multiple variables and lead to the aforementioned batch-to-batch inconsistency
While bovine and porcine collagen serve the larger biomaterials industry, on the smaller, laboratory scale, rat tails are the preferred source for type I collagen. Due to its high accessibility and homogeneity, the animal’s protein is now the dominant source for laboratory slides, cover slips and gels.
But there is a good reason that rat tail collagen is not as popular with the larger industry: its low yield and poor immunogenic profile. With its commercial collagen content limited to just its tail, the animal can hardly match the yields of its mammalian contemporaries. And when its structural fragility is considered, it is no wonder that industry projects tend to avoid rat tail collagen completely.
As the dangers and limitations of animal-derived collagen become clearer, many alternative sources are rapidly gaining interest. And one such burgeoning source might be unexpected: plants. Collagen is, after all, only found naturally in animals, so any plant-derived collagen is the product of genetic engineering. Now used for the treatment of various chronic and infectious diseases, plant collagen is quickly gaining a reputation for being economical, scalable, and safer than its bovine contemporaries.
However, as an un-natural source, plant collagen has its limitations. Most plant scaffolds form weaker and smaller fibre diame-ters than bovine materials1 and due to its farmed nature, production is at the mercy of environmental conditions such as droughts and blights.
Due to their safety and high natural collagen levels, animals such as fish, starfish, sponges and squid have been welcomed as exciting new collagen candidates. But one marine animal has a collagen content potentially different to any other: Jellyfish. Thanks to collagen contents exceeding 40% in certain species, evolutionary ancient lineage, no risk of BSE and a compatibility with every common collagen type, jellyfish-derived collagens are set to reshape the biomaterials industry.
Supporting cell culture? research
We offer a wide range of products to support cellculture research. These include antibodies, proteins and assay kits, in addition to specialised collagen binding peptides and products for tissue dissociation and cell culture.
Collagen scaffolds, plates and hydrogels for cell culture
Jellagen Marine Biotechnologies offers a portfolio of high-quality collagen scaffolds, collagen-coated plates and collagen hydrogels for cell culture. Derived from jellyfish, these products benefit from distinct functional advantages over mammalian-sourced materials, such as lower immunogenicity and greatly reduced non-specific miRNA content compared to mammalian collagens.
Recombinant Collagenase enzymes for tissue dissociation and cell isolation
Cell isolation represents a critical step in order to obtain a high number of living and functional cells and is usually performed by enzymatic digestion through collagenase-based blends: unfortunately current commercially available blends (“extractive collagenases”) present many limitations in terms of batches consistency and enzymes stability. This poses obstacles in developing reproducible and standardized protocols with a subsequent waste of material, time and an overall increase of the procedures’ costs.
Abiel’s recombinant collagenases are the only tissue dissociation enzymes that can be customized to adapt to the specific research application and guarantee the standardization, the reliability and consistency of results. Suitable for all tissue types, both Class I (COL G) and Class II (COL H) formulations are available and can be mixed to suit the requirements of the downstream application. These enzymes benefit from exceptional lot-to-lot consistency, eliminating the need to perform preliminary testing.