Collagen functionalisation by plasma coupled to chemical grafting

The promising trends in biotechnology and tissue engineering are based on the development of advanced materials with biomimetic features in order to recreate the native environment promoting the appropriate cell behavior for tissue regeneration. Cell therapy together with novel functionalized biomaterials represent a very promising approach in regenerative medicine for cartilage regeneration. Articular cartilage exhibits a well-ordered organization with an extracellular matrix arranged as a network of collagen fibers and proteoglycans that allow for cell adhesion, mechanical support, transduction of chemical and mechanical signals from the surrounding tissue to the cells. Electrospun materials are considered highly promising scaffolds for cartilage tissue engineering given their specific fibrous morphology that resembles the fibrous component of tissue extracellular matrix. Many synthetic and natural polymers have been successfully electrospun to obtain scaffolds. Among natural polymers, collagen is universally applied as biomaterial in regenerative medicine because of its unique biocompatibility, and structural property. Robust techniques for surface “biodecoration” are currently required and the appropriate surface functionalization still remains a critical variable for the optimal performance of a wide range of biomaterials. Covalent bonding of bioactive molecules to material surface is a valid strategy in order to allow a sufficiently strong and specific affinity of biomolecules with the surface itself; in addition covalent bonding may permit site-directed immobilization and preservation of specific conformation and exposition to control biological responses. Plasma processes allow to tune surface properties of materials with negligible effect on their bulk. The need of improving cell/surface interaction has decisively introduced plasma techniques in the field of biomaterials; In addition, a wide range of compounds can be chosen as a monomer for plasma polymerization, providing a great diversity of possible surface modifications with different functional groups, including amine, anhydride, epoxide, carboxylic acid, cyano, halide, hydroxyl, furfuryl, and perfluoroalkyl.