title: Co-extrusion of biocompatible polymers for scaffolds with co-continuous morphology.
abstract: A methodology for the preparation of porous scaffolds for tissue engineering using co-extrusion is presented. Poly(epsilon-caprolactone) is blended with poly(ethylene oxide) in a twinscrew extruder to form a two-phase material with micron-sized domains. Selective dissolution of the poly(ethylene oxide) with water results in a porous material. A range of blend volume fractions results in co-continuous networks of polymer and void spaces. Annealing studies demonstrate that the characteristic pore size may be increased to larger than 100 microm. The mechanical properties of the scaffolds are characterized by a compressive modulus on the order of 1 MPa at low strains but displaying a marked strain-dependence. The results of osteoblast seeding suggest it is possible to use co-extrusion to prepare polymer scaffolds without the introduction of toxic contaminants. Polymer co-extrusion is amenable to both laboratory- and industrial-scale production of scaffolds for tissue engineering and only requires rheological characterization of the blend components. This method leads to scaffolds that have continuous void space and controlled characteristic length scales without the use of potentially toxic organic solvents.
authors.affiliation: Polymers Division, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8542, Gaithersburg, Maryland 20899, USA. newell.washburn@nist.gov
authors.forename: Newell R
authors.initials: NR
authors.lastname: Washburn
authors.forename: Carl G
authors.initials: CG
authors.lastname: Simon
authors.forename: Alessandro
authors.initials: A
authors.lastname: Tona
authors.forename: Hoda M
authors.initials: HM
authors.lastname: Elgendy
authors.forename: Alamgir
authors.initials: A
authors.lastname: Karim
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Amis
mesh_terms: D000465:Algorithms; D001672:Biocompatible Materials; D001863:Bone Screws; D002478:Cells, Cultured; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D010006:Osteoblasts; D011091:Polyesters; D011092:Polyethylene Glycols; D011108:Polymers; D012212:Rheology; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014783:Viscosity
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011108:Polymers; C016240:polycaprolactone; D011092:Polyethylene Glycols