The effect of cefazolin and vancomycin on osteoblast-like cells was st
udied, Cells from the MG-63 human osteosarcoma cell line were grown in
antibiotic free media and exposed to concentrations of cefazolin and
vancomycin at order of magnitude intervals between 0 and 10,000 mu g/m
l, For cefazolin, a second interval was performed between 100 and 1000
mu g/ml to define toxic levels more accurately, Cell number and H-3-t
hymidine incorporation at 0, 24, and 72 hours were determined, The res
ults of this study show that local levels of vancomycin of 1000 mu g/m
l and less have little or no effect on osteoblast replication, and con
centrations of 10,000 mu g/ml cause cell death, Concentrations of cefa
zolin of 100 mu g/ml and less have little or no effect on osteoblast r
eplication, 200 mu g/ml significantly decrease cell replication, and 1
0,000 mu g/ml cause cell death, The authors conclude that vancomycin i
s less toxic than is cefazolin to osteoblasts at higher concentrations
and may be a better antibiotic for local administration in the treatm
ent of similarly sensitive bacterial infections.