title: Porous hybrid structures based on P(DLLA-co-TMC) and collagen for tissue engineering of small-diameter blood vessels.
abstract: Poly (D,L-lactide)-7co-(1,3-trimethylene carbonate) [P(DLLA-co-TMC)] (83 mol % DLLA) was used to produce matrices suitable for tissue engineering of small-diameter blood vessels. The copolymer was processed into tubular structures with a porosity of approximately 98% by melt spinning and fiber winding, thus obviating the need of organic solvents that may compromise subsequent cell culture. Unexpectedly, incubation in culture medium at 37 degrees C resulted in disconnection of the contact points between the polymer fibers. To improve the structural stability of these P(DLLA-co-TMC) scaffolds, a collagen microsponge was formed inside the pores of the synthetic matrix by dip coating and freeze drying. Hybrid structures with a porosity of 97% and an average pore size of 102 mum were obtained. Structural stability was preserved during incubation in culture medium at 37 degrees C. Smooth-muscle cells (SMCs) were seeded in these hybrid scaffolds and cultured under pulsatile flow conditions in a bioreactor (120 beats/min, 80-120 mmHg). After 7 days of culture in a dynamic environment viable SMCs were homogeneously distributed throughout the constructs, which were five times stronger and stiffer than noncultured scaffolds. Values for yield stress (2.8 +/- 0.6 MPa), stiffness (1.6 +/- 0.4 MPa), and yield strain (120% +/- 20%) were comparable to those of the human artery mesenterica.
authors.affiliation: Department of Polymer Chemistry and Biomaterials, Faculty of Science and Technology and Institute for Biomedical Technology (BMTI), University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Laura
authors.initials: L
authors.lastname: Buttafoco
authors.forename: Niels P
authors.initials: NP
authors.lastname: Boks
authors.forename: Paula
authors.initials: P
authors.lastname: Engbers-Buijtenhuijs
authors.forename: Dirk W
authors.initials: DW
authors.lastname: Grijpma
authors.forename: Andre A
authors.initials: AA
authors.lastname: Poot
authors.forename: Piet J
authors.initials: PJ
authors.lastname: Dijkstra
authors.forename: Istvan
authors.initials: I
authors.lastname: Vermes
authors.forename: Jan
authors.initials: J
authors.lastname: Feijen
mesh_terms: D001807:Blood Vessel Prosthesis; D002478:Cells, Cultured; D003094:Collagen; D004146:Dioxanes; D006801:Humans; D032389:Myocytes, Smooth Muscle; D011091:Polyesters; D016062:Porosity; D023822:Tissue Engineering
chemical_list: D004146:Dioxanes; D011091:Polyesters; C443643:trimethylene carbonate; C033616:poly(lactide); D003094:Collagen