title: Elastic biodegradable poly(glycolide-co-caprolactone) scaffold for tissue engineering.
abstract: Cyclic mechanical strain has been demonstrated to enhance the development and function of engineered smooth muscle (SM) tissues, and it would be necessary for the development of the elastic scaffolds if one wishes to engineer SM tissues under cyclic mechanical loading. This study reports on the development of an elastic scaffold fabricated from a biodegradable polymer. Biodegradable poly(glycolide-co-caprolactone) (PGCL) copolymer was synthesized from glycolide and epsilon-caprolactone in the presence of stannous octoate as catalyst. The copolymer was characterized by (1)H-NMR, gel permeation chromatography and differential scanning calorimetry. Scaffolds for tissue engineering applications were fabricated from PGCL copolymer using the solvent-casting and particle-leaching technique. The PGCL scaffolds produced in this fashion had open pore structures (average pore size = 250 microm) without the usual nonporous skin layer on external surfaces. Mechanical testing revealed that PGCL scaffolds were far more elastic than poly(lactic-co-glycolic acid) (PLGA) scaffolds fabricated using the same method. Tensile mechanical tests indicated that PGCL scaffolds could withstand an extension of 250% without cracking, which was much higher than withstood by PLGA scaffolds (10-15%). In addition, PGCL scaffolds achieved recoveries exceeding 96% at applied extensions of up to 230%, whereas PLGA scaffolds failed (cracked) at an applied strain of 20%. Dynamic mechanical tests showed that the permanent deformation of the PGCL scaffolds in a dry condition produced was less than 4% of the applied strain, when an elongation of 20% at a frequency of 1 Hz (1 cycle per second) was applied for 6 days. Moreover, PGCL scaffolds in a buffer solution also had permanent deformations less than 5% of the applied strain when an elongation of 10% at a frequency of 1 Hz was applied for 2 days. The usefulness of the PGCL scaffolds was demonstrated by engineering SM tissues in vivo. This study shows that the elastic PGCL scaffolds produced in this study could be used to engineer SM-containing tissues (e.g. blood vessels and bladders) in mechanically dynamic environments.
authors.affiliation: Biomaterials Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 130-650, Korea.
authors.forename: Soo-Hong
authors.initials: SH
authors.lastname: Lee
authors.forename: Byung-Soo
authors.initials: BS
authors.lastname: Kim
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Choi
authors.forename: Sung In
authors.initials: SI
authors.lastname: Jeong
authors.forename: Il Keun
authors.initials: IK
authors.lastname: Kwon
authors.forename: Sun Woong
authors.initials: SW
authors.lastname: Kang
authors.forename: Janeta
authors.initials: J
authors.lastname: Nikolovski
authors.forename: David J
authors.initials: DJ
authors.lastname: Mooney
authors.forename: Yang-Kyoo
authors.initials: YK
authors.lastname: Han
authors.forename: Young Ha
authors.initials: YH
authors.lastname: Kim
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002478:Cells, Cultured / Q000637:transplantation; D004548:Elasticity; D006027:Glycosides / Q000138:chemical synthesis / Q000737:chemistry*; D019344:Lactic Acid / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry*; D008297:Male; D008422:Materials Testing; D051379:Mice; D008819:Mice, Nude; D008855:Microscopy, Electron, Scanning; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D019906:Nuclear Magnetic Resonance, Biomolecular; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D013314:Stress, Mechanical; D013718:Tensile Strength; D023822:Tissue Engineering / Q000295:instrumentation*; D014183:Transplantation, Heterologous
chemical_list: D001672:Biocompatible Materials; D006027:Glycosides; D007783:Lactones; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid