TY - JOUR
T1 - Magnesium alloy AZ91 exhibits antimicrobial properties in vitro but not in vivo
AU - Brooks, Emily K.
AU - Ahn, Richard
AU - Tobias, Menachem E.
AU - Hansen, Lisa A.
AU - Luke-Marshall, Nicole R.
AU - Wild, Linda
AU - Campagnari, Anthony A.
AU - Ehrensberger, Mark T.
N1 - Publisher Copyright:
© 2017 Wiley Periodicals, Inc.
PY - 2018/1
Y1 - 2018/1
N2 - Magnesium alloys hold great promise for developing orthopedic implants that are biocompatible, biodegradable, and mechanically similar to bone tissue. This study evaluated the in vitro and in vivo antimicrobial properties of magnesium–9%aluminum–1%zinc (AZ91) and commercially pure titanium (cpTi) against Acinetobacter baumannii (Ab307). The in vitro results showed that as compared to cpTi, incubation with AZ91 significantly reduced both the planktonic (cpTi = 3.45e8, AZ91 = 8.97e7, p < 0.001) colony forming units (CFU) and biofilm-associated (cpTi = 3.89e8, AZ91 = 1.78e7, p = 0.01) CFU of Ab307. However, in vivo results showed no significant differences in the CFU enumerated from the cpTi and AZ91 implants following a 1-week implantation in an established rodent model of Ab307 implant associated infection (cpTi = 5.23e3, AZ91 = 2.46e3, p = 0.29). It is proposed that the in vitro results were associated with an increased pH in the bacterial culture as a result of the AZ91 corrosion process. The robust in vivo buffering capacity likely diminished this corrosion associated pH antimicrobial effect.
AB - Magnesium alloys hold great promise for developing orthopedic implants that are biocompatible, biodegradable, and mechanically similar to bone tissue. This study evaluated the in vitro and in vivo antimicrobial properties of magnesium–9%aluminum–1%zinc (AZ91) and commercially pure titanium (cpTi) against Acinetobacter baumannii (Ab307). The in vitro results showed that as compared to cpTi, incubation with AZ91 significantly reduced both the planktonic (cpTi = 3.45e8, AZ91 = 8.97e7, p < 0.001) colony forming units (CFU) and biofilm-associated (cpTi = 3.89e8, AZ91 = 1.78e7, p = 0.01) CFU of Ab307. However, in vivo results showed no significant differences in the CFU enumerated from the cpTi and AZ91 implants following a 1-week implantation in an established rodent model of Ab307 implant associated infection (cpTi = 5.23e3, AZ91 = 2.46e3, p = 0.29). It is proposed that the in vitro results were associated with an increased pH in the bacterial culture as a result of the AZ91 corrosion process. The robust in vivo buffering capacity likely diminished this corrosion associated pH antimicrobial effect.
KW - antimicrobial
KW - biodegradable
KW - in vivo
KW - infection
KW - magnesium
UR - http://www.scopus.com/inward/record.url?scp=85010953188&partnerID=8YFLogxK
U2 - 10.1002/jbm.b.33839
DO - 10.1002/jbm.b.33839
M3 - Article
C2 - 28130825
AN - SCOPUS:85010953188
SN - 1552-4973
VL - 106
SP - 221
EP - 227
JO - Journal of Biomedical Materials Research - Part B Applied Biomaterials
JF - Journal of Biomedical Materials Research - Part B Applied Biomaterials
IS - 1
ER -