title: Zonal release of proteins within tissue engineering scaffolds.
abstract: The manufacture of a scaffold for tissue engineering applications that can control the location and timing of growth factor release is described. The scaffold is formed by the sintering of poly(DL-lactic acid) (P(DL)LA) microparticles, plasticized with poly(ethylene glycol) (PEG), although the method can be used for many other polymer types. The microparticles were loaded with model proteins, trypsin and horseradish peroxidase (HRP), or recombinant human bone morphogenetic protein-2 (rhBMP-2). Entrapment efficiencies above 75% were achieved using a solid-in-oil-in-water system. Controlled release of active protein was achieved for at least 30 days. Microparticles were built into protein-loaded or protein-free layers and release of the protein was restricted to zones within the scaffold. Cell response to rhBMP-2 was tuneable by changing the dose of the rhBMP-2 released by varying the ratio of protein-loaded and protein-free microparticles within scaffolds. Zonal activity of rhBMP-2 on C2C12 cells was demonstrated. The scaffolds may find utility in applications where gradients of growth factors within 3D templates are required or where zonation of tissue growth is required.
authors.affiliation: Tissue Engineering Group, School of Pharmacy, The University of Nottingham, NG7 2RD, UK.
authors.forename: Tri
authors.initials: T
authors.lastname: Suciati
authors.forename: Daniel
authors.initials: D
authors.lastname: Howard
authors.forename: John
authors.initials: J
authors.lastname: Barry
authors.forename: Nicola M
authors.initials: NM
authors.lastname: Everitt
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Shakesheff
authors.forename: Felicity Raj
authors.initials: FR
authors.lastname: Rose
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000493:pharmacokinetics; D002460:Cell Line; D006133:Growth Substances / Q000493:pharmacokinetics*; D006735:Horseradish Peroxidase / Q000493:pharmacokinetics; D006801:Humans; D051379:Mice; D008863:Microspheres; D011506:Proteins / Q000493:pharmacokinetics*; D023822:Tissue Engineering; D016212:Transforming Growth Factor beta / Q000493:pharmacokinetics
chemical_list: C525718:BMP2 protein, human; D001672:Biocompatible Materials; C525719:Bmp2 protein, mouse; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D006133:Growth Substances; D011506:Proteins; D016212:Transforming Growth Factor beta; D006735:Horseradish Peroxidase