Immunomodulators that enhance macrophage function have been shown to be beneficial in a number of wound-healing models in humans and in experimental animals. The exact mechanism of this improved healing is unclear. To assess the role of
collagen biosynthesis, the
immunomodulator glucan phosphate was utilized in two murine models of wound healing, i.e., colon anastomosis and full-thickness skin incision. Tensile strength was evaluated using computer-assisted constant velocity tensiometry.
Collagen biosynthesis was determined by assaying
hydroxyproline content of
wound hydrolysates by N-(9-fluorenyl)methoxycarbonyl/
o-phthalaldehyde high-performance liquid chromatography. Experimental animals were treated with
(1-3)-beta-D-glucan phosphate (250 mg/kg) intravenously 24 hours prior to colon anastomosis or skin incision. A second dose of
glucan phosphate was given immediately postoperatively. Control animals received
dextrose and water (5% w/v) intravenously. Tensile strength and
hydroxyproline content were measured on postoperative Day 3. In the skin
wound model,
glucan phosphate treatment increased (P < 0.05) tensile strength by 42 per cent (342.5 +/- 12.2 vs 241.8 +/- 4.8 g), and
hydroxyproline content was increased by 23.5 per cent (242.0 +/- 14.4 vs 196.8 +/- 10.5 pmol/microg; P < 0.05). In the
glucan phosphate group, colon tensile strength was significantly (P < 0.05) increased by 34 per cent (34.2 +/- 2.3 g vs 45.8 +/- 2.1 g), and
hydroxyproline content was increased by 7 per cent (47.45 +/- 3.31 vs 44.34 +/- 3.74 pmol/microg). These data indicate that macrophage modulation with
glucan phosphate will increase tensile strength in experimental colon and skin
wounds. In addition, we observed a positive correlation between
glucan phosphate treatment,
wound tensile strength, and
collagen biosynthesis.