Synthesis, characterization and surface modification of low moduli poly(ether carbonate urethane)ureas for soft tissue engineering.
Flexible scaffolds are of great interest in engineering functional and mechano-active soft tissues as such scaffolds might allow mechanical stimuli to transfer effectively from the scaffolds to cells during tissue development. Towards this end, we have developed a family of flexible poly(ether carbonate urethane)ureas (PECUUs) with a triblock copolymer poly(trimethylene carbonate)-poly(ethylene oxide)-poly(trimethylene carbonate) (PTMC-PEO-PTMC) or pentablock copolymers PTMC-PEO-PPO-PEO-PTMC (PPO, polypropylene oxide) as soft segments, linked by 1,4-diisocyanatobutane and putrescine. All of the PECUUs had low glass transition temperatures (<-46 degrees C). The PTMC-PEO-PTMC-containing PECUUs had low tensile strength and breaking strain. Replacing PEO with the similar length PEO-PPO-PEO resulted in highly flexible and soft PECUUs possessing breaking strains of 362-711%, tensile strengths of 8-18MPa and moduli of 5.5-7.4MPa at room temperature in air. Under aqueous conditions at 37 degrees C, these polymers remained flexible while their moduli were decreased to 3.4-4.0MPa. PECUUs based on PTMC-PEO-PPO-PEO-PTMC were thermosensitive as the water content at 37 degrees C was lower than that at 4 degrees C. PECUU using PTMC-PEO-PTMC as a soft segment showed 30% weight loss over 6weeks in PBS at 37 degrees C, while that using PTMC-PEO-PPO-PEO-PTMC as a soft segment had weight loss <6%. Degradation products were found to lack cytotoxicity. The mechanical stresses and moduli of PECUUs based on PTMC-PEO-PPO-PEO-PTMC were unchanged during the degradation. To enhance cell adhesion, PECUUs were surface modified with Arg-Gly-Asp-Ser (RGDS). Smooth muscle cell adhesion was 114% of tissue culture polystyrene for unmodified PECUU and >180% for RGDS-modified PECUUs, with cell viability on both surfaces increasing during culture. These low moduli polyurethanes may find applications in engineering cardiovascular or other soft tissues.
Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA.
Feng
F
Wang
Zhenqing
Z
Li
John L
JL
Lannutti
William R
WR
Wagner
Jianjun
J
Guan
D000042:Absorption; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D040761:Biomimetic Materials / Q000737:chemistry; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D003460:Crystallization / Q000379:methods; D055119:Elastic Modulus; D005109:Extracellular Matrix / Q000737:chemistry; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D032389:Myocytes, Smooth Muscle / Q000166:cytology* / Q000502:physiology*; D010316:Particle Size; D011076:Polycarboxylate Cement / Q000737:chemistry*; D011140:Polyurethanes / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties; D013718:Tensile Strength; D023822:Tissue Engineering / Q000379:methods*
D001672:Biocompatible Materials; D011076:Polycarboxylate Cement; D011140:Polyurethanes; C005506:polycarbonate