2. Was invented specifically for this purpose?
3. Has it ever been used as such?
Short answer: No, Yes
Long answer:
In an article written by Una/Straight Dope the following is stated:
Super glue, Krazy glue, Eastman 910 and similar glues are all a
special type of glue called cyanoacrylates. Cyanoacrylates were
invented in 1942 by Dr. Harry Coover of Kodak Laboratories during
experiments to make a special extra-clear plastic suitable for gun
sights. [...] Seeing possibilities for a new adhesive, Kodak developed
"Eastman #910" (later "Eastman 910") a few years later as the first
true "super glue."
[...]
The use of cyanoacrylate glues in medicine was considered fairly early
on. Eastman Kodak and Ethicon began studying whether the glues could
be used to hold human tissue together for surgery. In 1964 Eastman
submitted an application to use cyanoacrylate glues to seal wounds to
the United States Food and Drug Administration (FDA). Soon afterward
Dr. Coover's glue did find use in Vietnam--reportedly in 1966
cyanoacrylates were tested on-site by a specially trained surgical
team, with impressive results.
1. Is superglue safe for sealing wounds?
As to current status of the component for surgical use (in USA):
[...] an improved cyanoacrylate glue was developed for medical
applications called "2-octyl-cyanoacrylate." This compound causes less
skin irritation and has improved flexibility and strength--at least
three times the strength of the butyl-based compound (reference 2). As
a result, in 1998 the FDA approved 2-octyl cyanoacrylate for use in
closing wounds and surgical incisions, and in 2001 approved it for use
as a "barrier against common bacterial microbes including certain
staphylococci, pseudomonads, and Escherichia coli" (reference 2). This
latest incarnation was marketed under the name Traumaseal as well as
the more popular Dermabond.
The whole article is an interesting read, just follow the link at the top.
For the sake of future availability I include the references used in the article here:
Hayes, Sharon Caskey. "Discovery of Super Glue helped land Coover in National Inventors Hall of Fame," Kingsport Times-News, July 11, 2004.
(2) Schwade, Nathan D. "Wound Adhesives, 2-Octyl Cyanoacrylate", eMedicine article, Apr. 10, 2002
Vinters HV, Galil KA, Lundie MJ, Kaufmann JC: The histotoxicity of cyanoacrylates. A selective review. Neuroradiology 1985; 27(4): 279-91
Fernandez, Tania (Dr) and Bliskovsky, Val (Dr). "Cyanoacrylate Technology: Stay Glued," Pharmbiz.com, Jan. 2, 2003
Perry LC: An evaluation of acute incisional strength with Traumaseal surgical tissue adhesive wound closure. Dimensional Analysis Systems Inc.
Jueneman, F, "Stick it to um," Industrial Research & Development, Aug. 1981, p. 19.
Quinn, J., & Kissack, J., "Tissue Adhesives for Laceration Repair During Sporting Events," Clinical Journal of Sports Medicine, Vol. 4 No. 4, 1994, p. 245