|
Octyl Cryanoacrylate
The
main ingredient of Super Glue is cyanoacrylate. When
exposed to moisture or alkaline sites on the surface, it
polymerizes to form a bond. Super Glue has been on the
market since 1958. Most industrial or household grade\
cyanoacrylate is shorter alkyl chain derivatives such as
methyl or ethyl cyanoacrylate (WPI’s #7341 and #7342).
They offer both strong bonding and economical price. They
are very useful for temporarily holding tissues such as
mounting specimens for microtome sectioning. However, they
are not suitable for bonding wounds on live animals. The
difficulties of using cyanoacrylate for bonding live
animals are: (1) a strong irritating odour; (2) quick loss
of bonding strength due to breakdown of the bonding by
hydration; (3) the breakdown products, cyanoacetate and
formaldehyde, are toxic and can cause inflammatory
reactions; and (4) they have low flexibility and tend to
be brittle. To overcome these problems, several longer
alkyl chain cyanoacrylates have been developed specially
for veterinary and human use. The first longer alkyl chain
product is butyl cyanoacrylate. This product has been used
for animal and human applications outside the USA since
1970. It is much less toxic and has a lower odour than the
methyl or ethyl cyanoacrylate. The butyl cyanoacrylate
that WPI offers is called Vetbond™.
A
family of super glues containing octyl cyanoacrylate, a
plasticizer and stabilizer, was developed In the 1990’s
(one of them approved by FDA for human use). When bonding
to tissue, these new adhesives are four times stronger and
less toxic than butyl cyanoacrylate. Compared with the
traditional suture, the new super glue has several
advantages.
On
average, it takes only one-tenth of the time to close an
incision. The bonding strength is equal to 5-0
monofilament suture. It also has a mysterious
antimicrobial effect that can decrease infection rates in
contaminated wounds. Bonding will slough off naturally in
5 to 7 days. Cosmetic appearance of the healed incision is
also better. Octal cyanoacrylate adhesive #500280 forms a
strong and flexible film and is thus more suitable for
surface wound bonding, protection, and holding a sensor or
other device on the tissue. Setting time is about 10
seconds, which gives ample time for application. It can
also be used for temporarily holding a live tissue. For
example, there is a report of using it to hold nematodes
on a glass slide for patch-clamp neurons recording. All of
the products offered by WPI are veterinary grade (not
suitable for human application). Though very similar to
the grade for human use, they are not sterile and do not
have FDA approval.
KWIK-CAST & KWIK-SIL
- Specially formulated for WPI
- Extremely low toxicity
- Excellent moisture resistance
- Cures at room temperature
The properties of
this adhesive make it exceptionally useful for
neuroscience applications, peripheral nerve studies and
similar biomedical applications. These new silicone
elastomers also eliminate the mess and time involved in
pre-mixing other commonly used formulations (such as
Wacker SilGel‘ and Sylgard‘). Each silicone elastomer
is packaged in a double barrel syringe and is
automatically mixed when pressed out of the mixer tip
provided. It can then be applied directly to the tissue
without further mixing. The curing time of these silicones
is short, reliable and reproducible thus eliminating
potential costly guesswork when using other tissue
adhesives. Furthermore, the curing process does not
produce heat, which can otherwise cause tissue damage.
WPI’s silicone elastomers are much less toxic than
dental silicone because they contain no surfactant
additives.
WPI’s silicone elastomers are based on recently
developed vinyl terminated siloxane and platinum complex
catalysts. They exhibit exceptional low toxicity before,
during and after curing. The traditional RTV silicone
systems produce either acetic acid or alcohol during
condensation; these compounds are toxic to living cells.
In contrast, the only by-product of condensation from
WPI’s elastomers is a small amount of hydrogen gas,
which was shown not to cause any effect on nerve activity
in highly sensitive peripheral nerves. Both elastomers
cure on contact with the tissue. Currently, WPI provides
rapid-curing silicone elastomers in two different
formulas:
Kwik-Sil™ is a translucent silicone elastomer adhesive
with medium viscosity. It has good adhesion and mechanical
property (tear strength and elongation). The very short
curing time (approx. 1 minute) make it especially useful
for moving preparations.
Kwik-Cast™ is a very low viscosity silicone elastomer
sealant. It is able to fill small spaces around nerves and
creates a continuous mass ensuring long-term recording
stability. Kwik-Cast is colour-coded so mixing is
foolproof. It can be applied and cured underneath mineral
oil. The slight longer curing time (approx. 3 minutes)
makes it more suitable for stationary preparations and in
vitro tissue studies.
|
français
+49
(0)30 6188845
+45 (0)36 988 355
Octyl
Cryanoacrylate, KWIK-CAST & KWIK-SIL
