An analysis of polymer type and chain length for use as a biological composite graft extender in impaction bone grafting: a mechanical and biocompatibility study.
Impaction bone grafting (IBG) with human allograft remains the preferred approach for replacement of lost bone stock during revision hip surgery. Associated problems include cost, disease transmission, and stem subsidence. Synthetic grafts are therefore appealing, and ideally display similar mechanical characteristics as allograft, but with enhanced ability to form de novo bone. High and low molecular weight forms of three different polymers [poly(DL-lactide) (P(DL) LA), poly(DL-lactide-co-glycolide) (P(DL) LGA), and poly(ε-caprolactone) (PCL)] were milled, impacted into discs, and then examined in a shear testing rig, in comparison to allograft. In addition, skeletal stem cells (SSCs) were combined with each of the milled polymers, followed by impaction and examination for cell viability and number, via fluorostaining and biochemical assays. The shear strengths of high/low mwt P(DL) LA, and high/low mwt P(DL) LGA were significantly higher than allograft (p < 0.01). High/low mwt PCL had significantly lower shear strengths (p < 0.01). WST-1 assay and fluorstaining indicated significantly increased cell viability on high mwt P(DL) LA and high mwt P(DL) LGA over allograft (p < 0.05). Mechanical and biochemical analysis indicated improved properties of high mwt P(DL) LA and high mwt P(DL) LGA over allograft. This study indicates the potential of these polymers for use as substitute human allograft, creating a living composition with SSC for application in IBG.
Bone and Joint Research Group, University of Southampton, SO16 6YD, United Kingdom.
Edward
E
Tayton
Sherif
S
Fahmy
Matthew
M
Purcell
Alexander
A
Aarvold
James O
JO
Smith
Spandan
S
Kalra
Adam
A
Briscoe
Stuart
S
Lanham
Steven
S
Howdle
Kevin
K
Shakesheff
Douglas G
DG
Dunlop
Richard O C
RO
Oreffo
D000368:Aged; D001672:Biocompatible Materials / Q000494:pharmacology*; D016025:Bone Transplantation; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008422:Materials Testing / Q000379:methods*; D055595:Mechanical Phenomena / Q000187:drug effects*; D008855:Microscopy, Electron, Scanning; D011108:Polymers / Q000737:chemistry*; D033081:Shear Strength / Q000187:drug effects; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects; D014184:Transplantation, Homologous; D055114:X-Ray Microtomography
D001672:Biocompatible Materials; D011108:Polymers