Commercial tissue adhesives such as fibrin, albumin-glutaraldehyde,
and cyanoacrylates often suffer from the limitations of adverse inflammatory
reactions, lack of bioactivity, and/or weak wet adhesion. There is
a need to develop advanced tissue adhesives which possess adequate
wet adhesion and appropriate biodegradability and biocompatibility.
The wet adhesion of the catechol group to a variety of substrates
is well-known. Further, it undergoes Michael addition with an amine
or thiol group, which makes catechol-containing polymers appealing
as tissue adhesives because there are abundant amine and thiol groups
in native tissue. We present here a composite tissue adhesive based
on a catechol-modified polymer that utilizes poly-l-lysine
(PLL) as a bridging molecule to promote the interfacing with cells
and tissues. Hyaluronic acid (HA) was chosen here as the polymer backbone
for functionalization with catechol moieties, which is attributable
to its multiple biological activities. The cross-linking conditions
of catechol-functionalized HA (HACA) were optimized, and the swelling
and degradation behavior of the cross-linked hydrogels were characterized.
The PLL/HACA-based adhesive demonstrated good adhesion to hydrogels
derived from collagen and gelatin that act as a simplified soft tissue
model, and to porcine skin tissue. Moreover, the adhesive supported
culture of a human umbilical vein endothelial cell line (HUV-EC-C)
with high cell viability and formation of capillary-like structure.
This may bring added benefit by means of promoting angiogenesis, therefore
promoting the integration between host tissue and implant. Our results
indicate that PLL/HACA could be a promising tissue adhesive for multiple
internal uses.