Synthesis, characterization, and cytocompatibility of elastomeric, biodegradable poly(ester-urethane)ureas based on poly(caprolactone) and putrescine.
The engineering of tissue for mechanically demanding applications in the cardiovascular system is likely to require mechanical conditioning of cell-scaffold constructs prior to their implantation. Scaffold properties amenable to such an application include high elasticity and strength coupled with controllable biodegradative and cell-adhesive properties. To fulfill such design criteria, we have synthesized a family of poly(ester-urethane)ureas (PEUUs) from polycaprolactone and 1,4-diisocyanatobutane. Lysine ethyl ester (Lys) or putrescine was used as chain extenders. To encourage cell adhesion, PEUUs were surface modified with radio-frequency glow discharge followed by coupling of Arg-Gly-Asp-Ser (RGDS). The synthesized PEUUs were highly flexible, with breaking strains of 660-895% and tensile strengths from 9.2-29 MPa. Incubation in aqueous buffer for 8 weeks resulted in mass loss, from >50% (Lys chain extender) to 10% (putrescine chain extender). Human endothelial cells cultured for 4 days with medium containing the degradation products from PEUUs with either the Lys or putrescine chain extender showed no toxic effects. Cell adhesion was 85% of that measured on tissue-culture polystyrene for unmodified PEUU surfaces (p < 0.01) and >160% (p < 0.001) of polystyrene on RGDS-modified PEUUs. These biodegradable PEUUs demonstrate potential for future application as cell scaffolds in cardiovascular tissue-engineering or other soft-tissue applications.
McGowan Institute for Regenerative Medicine, University of Pittsburgh, 300 Technology Drive, Pennsylvania 15219, USA.
Jianjun
J
Guan
Michael S
MS
Sacks
Eric J
EJ
Beckman
William R
WR
Wagner
D020341:Absorbable Implants; D001672:Biocompatible Materials; D001673:Biodegradation, Environmental; D002448:Cell Adhesion; D002455:Cell Division; D020724:Elastomers / Q000138:chemical synthesis / Q000627:therapeutic use*; D004727:Endothelium / Q000166:cytology; D006801:Humans; D008422:Materials Testing; D019563:Mechanics; D019637:Orthopedic Procedures; D011091:Polyesters; D011140:Polyurethanes; D011700:Putrescine; D023822:Tissue Engineering / Q000379:methods*
D001672:Biocompatible Materials; D020724:Elastomers; D011091:Polyesters; D011140:Polyurethanes; C016240:polycaprolactone; C044690:polyetherurethane urea; D011700:Putrescine