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Name (Title):
Tetsushi Taguchi (Senior Researcher)
Affiliation:
Biomaterials Center & International Center for Materials Nanoarchitectonics
(MANA), NIMS
Address:
1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
Email: TAGUCHI.Tetsushi@nims.go.jp
Home Page: http://www.nims.go.jp/bmc/
Presentation Title:
Improved anti-thrombogenic and endothelial cell adhesive properties of citric acid-crosslinked
collagen
Abstract:
Drug-eluting stents (DES) prevent in-stent restenosis by eluting drugs from matrices on DES to
suppress smooth muscle cell growth. However, the residual matrices on DES lead to complications
such as exaggerated inflammatory response, thrombus formation, and prevention of
endothelialization at the implant site after the drug elutes from the matrices. Therefore, it is
necessary to develop a novel biodegradable matrix with both anti-thrombogenic and endothelial cell
adhesion after the drug elution. We previously developed a novel crosslinker citric acid derivative
(CAD) with three active ester groups in order to prepare biopolymer-based materials [1-3].
In the present study, we report on a novel biodegradable matrix which has anti-thrombogenic
and cell adhesion properties; the study was part of our ongoing research on the matrices for drugeluting
stents. Using alkali-treated collagen (AlCol) and CAD (AlCol-CAD), we evaluated the
physicochemical properties such as swelling ratio, residual amino groups, and carboxyl groups of
the resulting AlCol-CAD in order to clarify influence of thrombus formation and cell adhesion
[4]. In vitro and in vivo evaluation of drug-encapsulated AlCol-CAD was also performed.
Fig. 1(A) shows the effect of CAD
concentration on thrombus formation of 15
w/v% AlCol-CAD. Significant thrombus
formation was observed on AtCol gel, AlCol-
GA, and AlCol-CAD (5 mM) after immersion
in rat arterial blood. Fig. 1(B) shows the
adhesion number of HUVECs on 7.5, and 15
w/v% AlCol-CAD with different CAD
concentrations. Aterocollagen (AtCol) gel and
AlCol-glutaraldehyde (GA) were used as
control materials. The adhesion number of
HUVECs on 15 w/v% AlCol-CAD increased
with increase in CAD concentration up to 20
mM, and then decrease with further increase
in CAD concentration.
These results suggested that the 15w/v%AlCol-CADs with higher CAD concentration than
20mM have great potential as matrices for DES.
Acknolwedgement:
This work was financially supported in part by grant-in-aid from National Institute of
Biomedical Innovation, Japan.
References:
1) T. Taguchi, et al., J. Nanosci. Nanotechnol., 7, 742, 2007., 2) T. Taguchi, et al., Mater. Sci.
Eng. C, 24, 775, 2004. 3) H. Saito and T. Taguchi, et al., Acta. Biomater., 3, 89, 2007., 4) H.
Saito and T. Taguchi, et al., Biomacromolecules, 8, 1992, 2007.
96
(A) (B)
Poster Session PB-2
Fig. 1 (A) Photographs of AlCol-CADs at different CAD
concentrations after immersion of gels in rat arterial blood
(a) 5 mM; (b) 20 mM; (c) AtCol gel; (d) AlCol-GA. (B)
Number of HUVECs adhered on AtCol gel, AlCol-GA
and AlCol-CAD at different CAD concentrations.