Evaluation of polycaprolactone scaffold degradation for 6 months in vitro and in vivo.
The use of polycaprolactone (PCL) as a biomaterial, especially in the fields of drug delivery and tissue engineering, has enjoyed significant growth. Understanding how such a device or scaffold eventually degrades in vivo is paramount as the defect site regenerates and remodels. Degradation studies of three-dimensional PCL and PCL-based composite scaffolds were conducted in vitro (in phosphate buffered saline) and in vivo (rabbit model). Results up to 6 months are reported. All samples recorded virtually no molecular weight changes after 6 months, with a maximum mass loss of only about 7% from the PCL-composite scaffolds degraded in vivo, and a minimum of 1% from PCL scaffolds. Overall, crystallinity increased slightly because of the effects of polymer recrystallization. This was also a contributory factor for the observed stiffness increment in some of the samples, while only the PCL-composite scaffold registered a decrease. Histological examination of the in vivo samples revealed good biocompatibility, with no adverse host tissue reactions up to 6 months. Preliminary results of medical-grade PCL scaffolds, which were implanted for 2 years in a critical-sized rabbit calvarial defect site, are also reported here and support our scaffold design goal for gradual and late molecular weight decreases combined with excellent long-term biocompatibility and bone regeneration.
Lam
Christopher X F
CX
Division of Bioengineering, National University of Singapore, Blk E3A #04-15, 7 Engineering Dr 1, Singapore 117574.
Hutmacher
Dietmar W
DW
Schantz
Jan-Thorsten
JT
Woodruff
Maria Ann
MA
Teoh
Swee Hin
SH
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000592:standards; D001861:Bone Regeneration; D002021:Buffers; D003460:Crystallization; D020007:Implants, Experimental; D008422:Materials Testing; D011091:Polyesters / Q000494:pharmacology* / Q000627:therapeutic use; D011817:Rabbits; D054457:Tissue Scaffolds / Q000737:chemistry* / Q000592:standards
D001672:Biocompatible Materials; D002021:Buffers; D011091:Polyesters; C016240:polycaprolactone