Mechanical reinforcement of Bioglass®-based scaffolds by novel polyvinyl-alcohol/microfibrillated cellulose composite coating

• Microfibrillated cellulose has been considered for the first time as coating material for Bioglass® scaffolds.
• PVA/MFC coatings exhibited homogeneous distribution and proper adhesion.
• PVA ensures the load transfer from the scaffold to the MFC fibers.
• PVA/MFC-coated samples exhibited a remarkable increase of tensile strength and toughness.
• Multiple fracture of fibrils induced arrest of the cracks in some cases.

The preparation and mechanical properties of Bioglass®-based porous scaffolds reinforced by a composite coating constituted by polyvinyl alcohol (PVA) and microfibrillated cellulose (MFC) are investigated. Samples produced by foam replication process and having nominally 90% of open porosity were coated by dipping into an aqueous solution of PVA and MFC. Tensile tests were conducted on samples according to a new testing methodology optimized for highly porous ceramics. The addition of PVA/MFC coating led to a 10 fold increase of the tensile strength of scaffolds. The reinforcing and toughening effect of the composite coating due to crack bridging and fracture of cellulose fibrils embedded in the PVA matrix was proved by SEM observations.