Impregnation of β‐tricalcium phosphate robocast scaffolds by in situ polymerization

Abstract

[EN]Ring-opening polymerization ofe-caprolactone (e-CL) andL-lactide (LLA) was performed to impregnateb-trical-cium phosphate (b-TCP) scaffolds fabricated by robocasting.Concentrated colloidal inks prepared fromb-TCP commercialpowders were used to fabricate porous structures consistingof a 3D mesh of interpenetrating rods.e-CL and LLA wereinsitupolymerized within the ceramic structure by using alipase and stannous octanoate, respectively, as catalysts. Theresults show that both the macropores inside the ceramicmesh and the micropores within the ceramic rods are full ofpolymer in either case. The mechanical properties of scaf-folds impregnated byin situpolymerization (ISP) are signifi-cantly increased over those of the bare structures, exhibiting similar values than those obtained by other, more aggres-sive, impregnation methods such as melt-immersion (MI).ISP using enzymatic catalysts requires a reduced processingtemperature which could facilitate the incorporation ofgrowth factors and other drugs into the polymer composi-tion, thus enhancing the bioactivity of the composite scaffold.The implications of these results for the optimization of themechanical and biological performance of scaffolds for bonetissue engineering applications are discussed.