The extracellular matrix (ECM) is a three-dimensional macromolecular network composed of structural proteins (collagens, elastin), adhesion/signalling proteins (fibronectin, laminins), different proteoglycans, glycoproteins and glycosaminoglycans (GAGs). GAGs are structurally complex, but their structure is simply made up of repeating disaccharide building blocks composed of alternating uronic acid and hexosamine units.

GAGs are usually classified into four classes : chondroitin sulfate/dermatan sulfate, heparin/heparan sulfate, keratan sulfate and Hyaluronan (HA). HA is the only non-sulfated GAG: it represents the least negatively-charged GAG, and has a unique capacity to bind and retain water molecules (Figure 1).

Figure 1: Hyaluronan in aqueous solution, with formation of water bridges.

In vivo, HA has many biological functions: the maintenance of the elastoviscosity of liquid connective tissues (joint synovial and eye vitreous fluid), the control of tissue hydration and mandywater transport, a role as a substrate for the assembly of proteoglycans , and numerous receptor-mediated roles in cellular functions and locomotion (Figure 2). With its broad array of biological activities, HA is also involved in pathological processes such as tumor progression, inflammation and wound healing.

Figure 2: Summary of HA cell surface receptors and of the actions that they control when linked
by HA
. Source: Fallacara et al., 2018 (Polymers)

Despite the important and various roles of GAGs – HA in particular – in health and disease, most 3D cell culture supports do not contain these crucial components of the ECM. As such, 3D hydrogel systems based on HA have a very poor physicochemical properties: it is impossible to maintain its properties in cell culture models with classical methods.

HCS Pharma owns a patent for a process allowing to keep all physiological properties of HA! The related product, BIOMIMESYS®, is what we called a hydroscaffold ; with our exclusive method, HA keeps its structure as a solid scaffold, while still behaving as a hydrogel by adsorbing water molecules… In summary, BIOMIMESYS® is based on a physiological HA that is biofunctionalized with other ECM components to mimic the in vivo ECM at best, as a basis for relevant 3D in vitro models.

Don’t wait to learn more about BIOMIMESYS® by checking our website, and about the role of HA in health and disease by reading our next related news … Stay connected!

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