Sulfonic Layer-by-Layer Nanocoatings Made Of Marine-Origin Polysaccharides As Models For Cell-GAGs-like Interactions

Most of the human body polysaccharides (Ps) are sulfated (sGAG) and non-sulfated glycosaminoglycans (GAGs), linked to core proteins in its majority, forming proteoglycans. GAGs vary on the sulfation degree, sulfonic group (Sg) position and base units. sGAGs have very high growth factors (GFs) affinity through the Sg, participating, e.g., in cell proliferation and differentiation. Non-sulfated ones are also crucial and may have similar functions by cell marker binding. In fact, several studies report that GAGs influence cell behaviour, which however is not fully understood. Actual models make difficult the transposition to 3D systems, where both GAGs and mechanical stability are needed. Layer-by-Layer (LbL) is a very versatile technique to produce nanostructured coatings over any 2D/3D structure and was herein applied to develop 2D models to study cell-GAGs-like interactions, using marine-origin Ps, chitosan (CHI) and carrageenans (CAR), which have equivalent functional groups to the ones found in GAGs: -COOH, -NH₂ and -SO₃H. CHI and κ, ι and λ CAR (1, 2 and 3 Sg, respectively) LbL assembling was characterized by QCM-D, modelled by Voigt model, AFM, SEM, XPS and the effect over SaOs-2 cell line biomineralization investigated. ALP activity and biomineralization of SaOs-2 was improved in the presence of the coatings, being significantly higher on ι Car coatings - Fig.1, indicating CAR have functions much more than attracting medium ions. CAR may be very reactive to SaOs-2 secretome and capture GFs, improving biomineralization. These models may be very interesting to study cell-materials interactions and easily brought over 3D scaffolds for tissue engineering applications.