Figure 1: Schematic drawing of the realized modification of titanium implant materials
Research interests of the Interface Chemistry and Biomaterials Group
Institute of Physical and Theoretical Chemistry, University of Regensburg
Collagen-coating of metallic implant
materials
Improving cell adhesion on titanium implants by covalent
immobilization of collagen
Rainer Müller and Jochen Abke, Institute of Physical and Theoretical
Chemistry, University of Regensburg
Richard Kujat and Peter Angele, Department of Trauma Surgery, University
Hospital Regensburg
The project was funded by the Deutsche Forschungsgemeinschaft (DFG) within the
program SPP 1100 "Grenzfläche zwischen Werkstoff und
Biosystem"
Published in: BIOmaterialien 2007, in press.
Abstract
Initial cell adhesion is a major requirement for the integration of any implant
material in the human body. Because it has been established that collagen
accelerates receptor-mediated cell adhesion, the aim of the present study was
to investigate the influence of titanium modification by covalent attachment of
fibrillar collagen on adhesion and proliferation of osteoblast-like cells.
Several silane coupling agents and cross-linking molecules have been tested to
connect metal and protein and to stabilize the bound collagen layer against
biodegradation. We found that immobilization of collagen was most effective
utilizing an amino group-containing silane and a water soluble carbodiimide,
the latter performing both covalent attachment and protein cross-linking. In
vitro-collagenase digestion revealed higher stability of the covalently bound
and cross-linked collagen layer compared to a physically adsorbed and
cross-linked collagen layer. Adhesion and proliferation of human
osteoblast-like cells (MG-63) was enhanced on titanium biomaterials that have
been modified with covalently immobilized and cross-linked fibrillar
collagen.
Influence of surface pretreatment of titanium- and
cobalt-based biomaterials on covalent immobilization of fibrillar
collagen
Rainer Müller, Jochen Abke and Edith Schnell, Institute of Physical and
Theoretical Chemistry, University of Regensburg
Richard Kujat, Carsten Englert, Darius Taheri, Michael Nerlich and Peter
Angele, Department of Trauma Surgery, University Hospital Regensburg
Dieter Scharnweber, Institute of Materials Science, Technical University of
Dresden
The project was funded by the Deutsche Forschungsgemeinschaft (DFG) within the
program SPP 1100 "Grenzfläche zwischen Werkstoff und
Biosystem"
Published in: Biomaterials 2006, 27, 4059-4068.
Abstract
Collagen type-I is a major component of the extracellular matrix of most
tissues and it is increasingly utilized for surface engineering of biomaterials
to accelerate receptor-mediated cell adhesion. In the present study, coatings
with layers of fibrillar type-I collagen were prepared on titanium, titanium
alloy, and cobalt alloy to improve initial osteoblast adhesion and
implant-tissue-integration. To suppress the quick in vivo degradation rate of
collagen the deposited layers were covalently immobilized at the metal surfaces
as well as chemically cross-linked. The application of different oxidation
techniques to the metallic substrates resulted in surfaces with varying
hydroxyl group contents, which directly influenced the amount of immobilized
silane coupling agents. It was found that a high density of surface-bound
coupling agents increased the stability of the covalently linked collagen
layers. After coating of metallic biomaterials with a cross-linked collagen
layer, an improved cellular response of human osteoblast-like cells (MG-63) in
vitro could be recognized.
Surface engineering of stainless steel materials by tantalum
coating and collagen immobilization to improve implant
biocompatibility
Rainer Müller, Jochen Abke and Edith Schnell, Institute of Physical and
Theoretical Chemistry, University of Regensburg
Richard Kujat, Carsten Englert, Michael Nerlich and Peter Angele, Department of
Trauma Surgery, University Hospital Regensburg
Frank Macionczyk and Uwe Gburek, Department of Functional Materials in Medicine
and Dentistry, University of Würzburg
Zbigniev Ruszczak and Robert Mehrl, Innocoll GmbH, Saal an der Donau
(Germany)
The project was supported by the Bavarian Research Foundation and the Bavarian
State Ministry of Sciences, Research and the Arts within the program FORBIOMAT
II
Published in: Biomaterials 2005, 26, 6962-6972.
Abstract
A multilevel platform coating of stainless steel implant materials is
introduced. The deposition of thin films of tantalum and tantalum oxide
enhanced the long-time biocompatibility of stainless steel biomaterials due to
an increase of their corrosion resistance. The additional coating with a layer
of collagen lead to an improved cell adhesion, which was the basis for
successful implant-tissue-integration. Because of the high degeneration rate of
natural collagen in vivo the deposited collagen layer was covalently
immobilized at the metal surface as well as chemically cross-linked. This was
achieved by using silane coupling agents and linker molecules for chemical
collagen binding and water-soluble carbodiimide for collagen cross-linking. The
biological response induced by the surface modifications was evaluated by in
vitro cell culture with human mesenchymal stem cells as well as by in vivo
subcutaneous implantation into nude mice. The presence of collagen clearly
improved the cytocompatibility of the stainless steel implants which,
nevertheless, significantly depended on the cross-linking degree of the
collagen layer.
Last update on 17.11.2009 - For more informations please contact Dr. Rainer Müller