Eradication of Wound Biofilms by Electrical Stimulation - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 423

current was delivered to the pins via a platinum anode. The pin site wounds were
scored for infection at day 21, with infection rates of 89 % in the control group, and
only 11 % in the LIDC group. Del Pozo et al. ( 2009b ) later tested LIDC therapy
versus antibiotic therapy in a chronic foreign body osteomyelitis rabbit model.
Osteomyelitis is very serious complication of chronic wounds and lengthens the
chronicity and difficulty in treating these infections. In this study, the tibias of
rabbits were infected with S. epidermidis and these biofilm-associated infections
went 4 weeks before therapy was applied. After 4 weeks of infection, the rabbits
were divided into three groups: a control group receiving no treatment, an antibiotic
group receiving daily intravenous doxycline, and an electrical current group receiv-
ing 200 A of continuous LIDC. Following 4 weeks of treatment the bacterial load

was reduced by 38 % in the doxycline- and 73 % in the electrical current-treated
groups as compared to the control. These in vivo studies with LIDC appear
promising with clinically relevant electrical intensities, although the extensive
duration of electrical treatment (21 continuous days) would be clinically difficult.

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6.3 Human Studies with Low-Intensity Direct Current
and Biofilms

In the first extensive clinical trial treating ischemic ulcers with LIDC (as discussed
above), Wolcott et al. ( 1969 ) reported that most initial wound swab cultures
detected the presence of the Pseudomonas and Proteus genera. However, after
several days of ES the majority of secondary wound cultures were free of patho-
gens. Bolton et al. ( 1980 ) conducted a human study investigating what effect LIDC
had on 24 h S. epidermidis biofilms inoculated on the epidermis. A 24 h treatment
with 100 A cathodic LIDC resulted in complete eradication of S. epidermidis on

the human volunteer's skin. An additional human study by Fakhri and Amin
examined LIDC treatment on 20 non-healing burn wound infections (Fakhri and
Amin 1987 ). For the study, antibiotic treatment was stopped during the electrical
stimulation therapy. At the beginning of the study, patient wound swabs cultured
positive for P. aeruginosa , S. aureus , and Escherichia coli . However, 10 min,
biweekly applications of 25 mA LIDC resulted in wound swabs that came back
as sterile or with a lowered bacterial burden. In summary these findings support the
idea that LIDC treatment alone stimulates wound healing via the eradication of the
bacterial biofilm burden in wounds.

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