Biomaterials 26 (2005) 5276–5284
Preparation and characterization of porous b-tricalcium phosphate/
collagen composites with an integrated structure
, Wenjian Weng
, Kui Cheng
, Xinggang Liu
, Ge Shen
Department of Materials Science and Engineering, Zhejiang University, Zheda Road No. 38, Hangzhou, Zhejiang 310027, China
School of Stomatology, Beijing University, Beijing 100081, China
Received 28 November 2004; accepted 26 January 2005
Available online 13 March 2005
Porous b-tricalcium phosphate (TCP)/collagen composites with different b-TCP/collagen weight ratio were prepared. The
inﬂuences of the preparation conditions on the microstructure of porous composite and the joint status of b-TCP particles with
collagen ﬁbrils were characterized by X-ray diffractometer, scanning electron microscopy and transmission electron microscopy.
The results showed: (1) an acid treatment could effectively disassemble collagen ﬁbrils; (2) in the resulting porous composites, b-TCP
particles homogenously existed on the skeleton of the collagen ﬁbril network and bonded tightly to both the ﬁbrils and themselves.
The tight bonding formation could be due to the reaction between Ca ions in the particles and carboxyl groups in collagen
polypeptide chains and due to the reprecipitation of partially dissolved b-TCP duringsynthesis. The tight bondingbetween b-TCP
particles and collagen ﬁbrils in the composites demonstrated an integrated structure, which was reproducible when b-TCP/collagen
ratio ranged from 2 to 4. Such integrated structure would make signiﬁcant contributions in reliably tailoring properties of the
porous composites by varying b-TCP content. In addition, the porous composites had large porosity ($95%) and appropriate pore
size ($100 mm), showed no negative impact in cytotoxicity assay and complete bone tissue regeneration after 12 weeks in animal test.
r 2005 Elsevier Ltd. All rights reserved.
Keywords: b-tricalcium phosphate; Collagen; Porous composite; Preparation; Microstructure; Scaffold
Bone tissue engineering provides a new way for
regenerating bone tissues to repair damaged or diseased
ones completely [1,2], the technique should have a highly
porous network as a scaffold to accommodate seeding
cells to culture in vitro and ﬁnally form bone tissues in
body [3–6]. The scaffolds are made of biodegradable
materials with biocompatibility for eliminatinghost
immune rejection response, biodegradability for ensur-
ingcomplete tissue regeneration in the repair area, and
osteoconduction for facilitatingbone formation.
Many biomaterials includingpolymers and inorganic/
organic composites have been prepared, aiming to act as
scaffolds for bone tissue engineering in recent years
[7–13]. It has been demonstrated that b-tricalcium
phosphate (b-TCP)/collagen composite is one of the
best approaches to meetingthe requirements of bone
tissue engineering scaffolds to the utmost extent. That is
because b-TCP has good biodegradability and osteo-
conductivity [14–17], while collagen is a major compo-
nent of bone and has good cell attachment ability
besides good biodegradability [18,19]. It is suggested for
the composites that b-TCP particles should be ﬁne, well
distributed in composite, and well bonded to collagen
ﬁbrils as an integration, only with which the uniform
microenvironment within the composite can be ob-
tained, the advantages of the composites can be
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