Healing of linear, non-perforating thermal burns was studied in 56 hum
an corneas in an air/liquid organ culture system in serum free medium
or in media supplemented with 10% fetal bovine serum, 10% human serum
or 10% human plasma. The extent of epithelial wound healing was determ
ined by measuring epithelial growth into the wound using digitized com
puter scanning of light micrographs of 1 mu m sections. The cross-sect
ional area of this epithelial growth entering the wound was significan
tly greater for corneas incubated with either human serum (16,350 +/-
12,088 mu m(2)/day; p < 0.0001) or human plasma (20,571 +/- 12,276 mu
m(2)/day; p = 0.0004) than for those incubated in serum free (1,784 +/
- 1,957 mu m(2)/ day) medium. There was no significant difference betw
een epithelial growth in the serum free and fetal bovine serum supplem
ented (3,779 +/- 2,580 mu m(2)/day) media or between that in human ser
um and human plasma supplemented media. The thickness of the epitheliu
m adjacent to the wound was greater in corneas cultured in fetal bovin
e serum supplemented media than in corneas cultured in the presence of
human serum. Similarly, the build-up of epithelium at the wound edge
for corneas in either serum free or fetal bovine serum supplemented me
dia was significantly greater than for either human serum or human pla
sma supplemented media. The percentage of basal epithelial nuclei whic
h incorporated bromodeoxyuridine (BrdU) increased during the first thr
ee days of culture when it reached a plateau. Comparison of paired wou
nded and unwounded corneas showed that wounding stimulated an increase
in DNA synthesis. The extent of labelling was similar after seven day
s for both serum free medium and human serum supplemented medium, indi
cating that a serum-factor was not necessary for this stimulation. Imm
unohistochemical (IHC) analysis showed that fibronectin was present ar
ound the wound edges, in the stroma and along the basement membrane of
the epithelium, after seven days of culture in either serum free or h
uman serum containing media. Type IV collagen was found in the basemen
t membrane of both groups but appeared along the wound edge and surrou
nding the epithelial cell influx into the wound in human serum culture
d corneas only. This cultured human cornea system offers a useful mode
l for examining factors which modulate the course of wound healing.