Jérôme Chevalier INSA de Lyon

Ceramics for biomedical applications
from materials to tissue engineering
Jérôme Chevalier, INSA de Lyon
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OUTLINE
- Introduction and context: an aging population, with hopes for
a better life.
- The place of biomaterials (and ceramics) in medical devices.
- Engineering with ceramics: orthopaedic devices.
- Towards bioactive medical systems and tissue engineering :
Calcium phosphate ceramics for bone regeneration.
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Introduction and context
An aging population in European countries (ex. Germany)
- Number of Hip Replacement Surgery : about 1 Million/year in Europe,
- Osteoporosis : 50% of women (15% of the population above 50 y),
- 30 Millions of persons are suffering back pain : 150.000 invasive
fusion surgeries per year.

Introduction and context
The place of biomaterials (ceramics) in medical devices

Introduction and context
A continuous demand for long-lasting implants
A trend towards tissue regeneration (tissue engineering)
Materials and Biological Engineering
Regenerate
Repair
Number of THRs per year in Sweden

Engineering with ceramics: orthopaedics
‘Bio-inert’ ceramics for hip (knee) joint prosthesis applications
specifications
Bio-mechanical loads (4-10 KN): need for crack resistance
Wear (2 Mc/y): need for wear resistance
Ceramic head
PE or ceramic cup
Body fluid : need for long term stability, 15
(today) or even 30 years (future generations,
young patients)
(pH 5.5 - 7.4, Proteins, Cells)
Current lifetime :
15 years, revision surgery : up to 100.000€, 1-3% death

Engineering with ceramics: orthopaedics
Main advantage of ceramics : low wear rate
Multifactorial issue : ex : wear debris inflammation osteolysis Asceptic looseing
1990
2002
Aseptic Loosening : by far
the main cause of revision
Problems with Polyethylene
Very strong issues with metals

Engineering with ceramics: orthopaedics
Main advantage of ceramics : low wear rate
‘’Hip Simulators’ :
Predict wear rates in vitro with relevant tests
‘’Cell-debris interactions’ :
Understand the role of debris on loosening

Engineering with ceramics: orthopaedics
- Fracture of ceramics has been widely discussed (over-emphasized)
- Other components may fracture (fatigue of metal)!
- Fracture rates are becoming very rare (

Engineering with ceramics: orthopaedics
A challenge : tougher, stronger ceramics for orthopaedic implants
Opening the door to new medical devices
Phase transformation toughening
Giving some ‘plasticity’ to ceramics !
Load (N)
500
450
400
350
300
250
200
150
100
50
Bi-axial bending
- Strengthening (1000 MPa) by :
Decrease of grain size
- Toughening (20 MPa.m 1/2 ) by :
Phase transformation toughening
Crack deflection and bridging
0
0 20 40 60 80 100 120
Displacement (microns)
! ! !

Engineering with ceramics: orthopaedics
A new inter-vertebral spine prosthesis
(mechanics, materials, physics, chemistry, tissue interactions)
!

Engineering with ceramics: orthopaedics
Surface functionalization as a trigger of bone integration
Mechanical anchoring Laser patterning
Self Assembly Monolayers
(SAMS) – (silanisation)
without
with

Biactive ceramics and tissue engineering
Towards bone regeneration ?
• Extracellular Matrix
10% water
25% organic material
o Collagen
o Growth factors
65% Mineral part
o Calcium Phosphate (ceramic!)
Ca 10 (PO 4 ) 6 (OH) 2
Ceramic engineers are able to synthesise
Hydroxyapatite powders
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Biactive ceramics and tissue engineering
60% of Hip prostheses are coated
with Hydroxyapatite

Biactive ceramics and tissue engineering
Mixing CaP granules with bone fragments
Bone marrow sampling
Mixing
Implantation : bone volume increase,
trigger bone growth

Biactive ceramics and tissue engineering
Current trends : CaP cements – Additive manufacturing
Additive manufacturing of composite scaffolds (ex. HAP + Collagen)
+ Cells
is a realistic challenge
60j

Biactive ceramics and tissue engineering
Bone tissue engineering : creating bone with biomaterials
BMP2
TGFβ
Growth factors
Adhesion proteins
RGD Sequence

Thank you !
Jerome.chevalier@insa-lyon.fr
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