Human placental extracts are known to help wound healing.
Rapid migration of neutrophils to the wound site is a prerequisite to the wound healing process.
Gel filtration analysis of heat-treated placental extract gave the initial cue to the small nature of the migration promoting factor of the extract.
HPLC analysis of the extract revealed glutamate to be the predominant free amino acid.
Our studies show that glutamate at an optimum concentration of 8 microM induced phenotypic neutrophil chemotaxis, as seen in the time lapse and transwell assays.
Glutamate was also found to induce chemokinesis of the neutrophil, though the stimulation of chemotaxis was more pronounced.
The glutamate induced chemotaxis was accompanied by polarization of the actin cytoskeleton, and by polymerization of F-actin.
These data indicate that glutamate has a strong chemotactic functionality in the neutrophil, which could be of interest both therapeutically and in further investigation of the molecular basis of chemotaxis. 
One more intriguing thing has been detected in placental extract ability to affect wound healing is fibronectin.
A peptide of around 7.4 kDa has been purified from the aqueous extract of human placenta used as wound healer.
Derived partial amino acid sequence from mass spectrometric analysis showed its homology with human fibronectin type III.
Under nondenaturing condition, it formed aggregate, the elution pattern of which from reverse-phase HPLC was identical with that of fibronectin type III.
Immuno-blot of the peptide with reference fibronectin type III-C showed strong cross reactivity.
Since fibronectin type III plays important roles in wound healing, similar peptide in the extract is likely to take part in curing process.