Introduction:
Synechococcus elongatus
is a cyanobacterium that grows photoautotrophically. We hypothesized that a biologic gel containing
S. elongatus
could provide O
2
via photosynthesis to ischemic tissue due to peripheral arterial disease to accelerate wound healing.
Methods:
Sodium hyaluronate powder was mixed with cyanobacterial growth media BG11 at 2wt% to create the gel.
S. elongatus
was added at 100 million cells/mL to create the biologic gel. Wistar rats (control, n=12; gel, n=10; biologic gel in light, n=13; biologic gel in dark, n=10), after femoral artery ligation, received an ipsilateral wound of 1cm in diameter on the tarsal surface using electrocautery. Wound dressings were changed daily. Lesions were harvested on day 7 for histology evaluation, and blood samples were collected.
Results:
Rat tarsal tissue O
2
level had the largest fold change after applying biologic gel in light (7.0±1.5) compared to the control (1.7±0.3,
p
=.004), gel (2.6±0.4,
p
=.0007), and biologic gel in dark groups (1.8±0.3,
p
<.0001). Tarsal lesions after 7 days of treatment are shown in
Fig.1A
. Compared to controls, average wound areas were the smallest in rats receiving biologic gel in light on days 3, 5, and 7 (
Fig.1B
). Rats that received biologic gel in light took 12±1.1 days to heal, faster than the control, gel, and biologic gel in dark groups (
Fig.1C
). C-reactive protein level was zero for all rats, and none had positive blood culture. There was no difference in complete blood count on day 7 among the groups. Rats that received biologic gel in light compared to other groups demonstrated less tissue destruction and enhanced remodeling on day 7 (
Fig.1D-K
).
Conclusions:
The sodium hyaluronate-
S. elongatus
biologic gel was effective in accelerating wound healing in a peripheral arterial disease model by delivering oxygen to ischemic tissues. This photon-powered biologic gel shows potential for application as a novel wound dressing capable of promoting tissue formation and remodeling.
The comparison of complete blood count parameters between acute and chronic peripheral arterial disease
