Acidity near eroding polylactide-polyglycolide in vitro and in vivo in rabbit tibial bone chambers.
Eroding poly(DL-lactide-co-glycolide)(PDLLG) washers were observed chronically in vitro and in vivo following loading in a bone chamber tibial implant (BCI). Images were recorded using intravital microscopy of the implanted rabbit and direct pH measurements were obtained of the tissue in the bone chamber using a combination probe-reference microelectrode. While statistically significant pH differences were found between the control (unloaded) and experimental (PDLLG-bearing) BCIs, they were only of the order of 0.2 pH units. This value proved to be physiologically insignificant as no statistically significant difference in bone defect healing, as indicated by angiogenesis, was detected. It was shown that the measured small pH changes during PDLLG washers erosion would result whether the buffer was phosphate-buffered saline replaced weekly or interstitial fluid subject to vascular exchanges.
Martin
C
C
Department of Biomedical Engineering, University of Southern California, Los Angeles 90007, USA.
Winet
H
H
Bao
J Y
JY
D000818:Animals; D001672:Biocompatible Materials / Q000378:metabolism*; D001842:Bone and Bones / Q000098:blood supply / Q000378:metabolism*; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000378:metabolism*; D019736:Prostheses and Implants; D011475:Prosthesis Failure; D011817:Rabbits; D013977:Tibia
D001672:Biocompatible Materials; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid