Comparative Properties of Ethyl, n -Butyl, and n -Octyl Cyanoacrylate Bioadhesives Intended for Wound Closure - Biologically Responsive Biomaterials for Tissue Engineering - page 89

et al. [ 13 ] used alkyl cyanoacrylates as skin sealants for plastic surgery. The study
compares the effectiveness of the suture versus bioadhesives in 100 patients with
225 skin wounds and 16 nasal implants. Similar performance was obtained by
using the suture and the bioadhesive. More recently poly (alkyl cyanoacrylates)
have been proposed as raw materials for the synthesis of nanoparticles intended as
drug delivery carriers [ 14 ] .
If medical use of cyanoacrylate glues goes back to the half of the last century,
especially for military applications, only in the last two decades the US Food and
Drug Administration (FDA) approved some classes of cyanoacrylates as biocom-
patible compounds, http://www.fda.gov/AboutFDA/CentersOf fi ces/CDRH/
CDRHReports/ucm127557.htm . With the recent decision of an FDA expert panel
of reclassifying the cyanoacrylate topical skin adhesives from class III device
(that requires performance of new clinical trial to receive approval) to class II
device (requiring only the demonstration of substantial equivalency to a currently
approved predicate device), it can be anticipated that many new cyanoacrylate
monomers will become available in the United States in the near future.
However, despite producing effective sealing, the use of cyanoacrylate mono-
mers showed exothermal cure and high stiff polymerized product of considerable
strength but fragile at the same time. In addition, erosion, ulceration, and areas of
necrosis in surrounding (or adjacent) tissues may occur. One easy route to reduce
the exothermic reaction and stiffness of the cured cyanoacrylates is to increase the
length of the alkyl hydrocarbon chain in the monomer.
To the best of our knowledge there are only scarce papers and literature com-
paring the performance of cyanoacrylate adhesives with different hydrocarbon
chain length and most of them are devoted to clinical studies. Recently, Dossi
et al. [ 3 ] studied the anionic polymerization of ethyl, n -butyl, and n -octyl cyano-
acrylate in water. They found that an aqueous dispersion medium at pH around 5
and 65 °C gave the best cure performance and polymer properties. Both low- and
high-molecular-weight polymeric chains were found but at room temperature the
amount of high-molecular-weight polymer became more noticeable. Charters
[ 15 ] compared three tissue commercial adhesives: Indermil ® (ECN), Liquiband ®
( n -butyl cyanoacrylate (BCN)), and Dermabond ® (octyl cyanoacrylate) in the
treatment of 39,000 children patients. None of the glues were reported to be
completely pain free. However, the Liquiband ® tissue adhesive produced an aver-
age pain score of only 0.1 as compared to the Dermabond ® tissue adhesive scored
as 0.97. Liquiband ® was the best tissue adhesive in terms of wound closure and
ease of use. However, the only tissue adhesive with complete success was
Indermil ® . All of the tissue adhesives examined produced satisfactory results in
terms of wound closure. N. G. Senchenya et al. [ 16 ] polymerized different cyano-
acrylate monomers by thermal treatment and established that their glass transi-
tion temperatures depended on both the chemical structure and the kinetics of
curing of the monomers. On the other hand, they showed that the elastic modulus
decreased by increasing the length of the alkyl hydrocarbon chain of the cyano-
acrylate monomer. D. H. Park et al . [ 17 ] studied the kinetics of degradation and