Training School, Zagreb, 26-29 April 2014 1 Nata!a Drnov!ek, Sa!a Novak Jo"ef Stefan Institute Ljubljana, Slovenia From nano to macro biomaterials (design, processing, characterization, modeling) and applications to stem cells regenerative orthopedic and dental medicine (NAMABIO) Action MP1005
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Training School, Zagreb, 26-29 April 2014 1
Nata!a Drnov!ek, Sa!a Novak Jo"ef Stefan Institute Ljubljana, Slovenia
From nano to macro biomaterials (design, processing, characterization, modeling) and applications to stem cells regenerative orthopedic and dental medicine (NAMABIO) Action MP1005
Further interests
Regards from Ljubljana
1. Classification of biomaterials: !! General introduction !! Classification of biomaterials !! Relevant properties !! Types of biomaterials !! Tayloring the properties
2. Processing of bulk implants and coatings !! Introduction in colloidal and surface chemistry, electrophoretic deposition,
sol-gel, Hydrothermal treatment !! Deposition of coatings !! Case studies: TiO2, PEEK, bioactive glass coatings, antibacterial coatings; 3. Processing of scaffolds !! Basic requirements for the scaffolds; shaping techniques; issues; ..
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From nano to macro biomaterials (design, processing, characterization, modeling) and applications to stem cells regenerative orthopedic and dental medicine (NAMABIO) Action MP1005
Training School, Zagreb, 26-29 April 2014
What are "biomaterials?! Non-viable materials used in medical devices intended to interact with biological systems" (D. F. Wiliams, 1987)
"! 3rd Generation (>2000): Tissue regeneration (cell and gene activation)
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Bone is the second transplanted tissue after blood (UK) http://www.slideshare.net/Maxisurgeon/download-biomaterials-powerpoint
Vitalium:Co-Cr-Mo alloy
by source "! natural
!! Autograft - autologous (or autogenous): bone obtained from the same individual receiving the graft
!! Allograft: harvested from an individual other than the one receiving the graft
!! Xenografts: origin from a species other than human (e.g. bovine, wood)
"! synthetic
by biological role "! toxic "! bioinert: does not interact with the body "! bioactive: actively participate in tissue repair "! bioresorbable: resorb and provide elements for the tissue repair
by the function (duration of use) "! Temporary
!! Non-resorbable support to be removed !! biodegradable support - scaffold
"! Permanent
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by composition "! Metals & alloys "! Polymers "! Ceramic, glass, glass-ceramic "! Natural materials (from plants and animals)
Si/Ca - stimulative for osteoblasts, proliferation and differentiation Higher reactivity and faster osseointegration Biodegradable (can be taylored) Bioactive
Biodegradable Brittle!!!
Advantages
Issues
Consider a timescale of the implant being in the body
months, years, decades
!! The mechanical properties of the material may change (also those for the natural bone do!)
!! Ions are released from the materials (may cause inflammation and adverse health effects)
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Too high elastic modulus (Stress shielding) "! Porosity lowers the E-modulus (but pay attention to strenght) Brittleness: "! Reinforcement by particles
(e.g. ZrO2 in Al2O3 ceramics) or by fibers
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0
50
100
150
200
250
0 20 40 60 80 100
E (G
Pa)
Porosity (%)
Zirconia
A. Gantar, .....
50% gellan gum + 50% BAG
A. Gantar, IJS
Corrosion, metal ions release protective coating, avoiding toxic elements
Hydrophobicity etching, photocatalitic coating
Cell attachment roughnening
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HA formation Highly bioactive coating (BAG) Tailoring the roughness Tailoring the surface chemistry (surface charge, OH– or COOH-)
21 Enhanced HA formation on Ti by NaOH
Protein attachements Surface charge, hidrophilicity, irradiation Cell attachment Bioactive coatings Surface charge modification Hydrophilicity Inflammation Antibacterial or bactericidal coating Avoiding toxic and allergenic elements Hydrophobicity
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Day 3
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•! There is no ideal synthetic biomaterial
•! A good balance between the advantages and issues is needed (not on account of adverse biological response!)
•! A good design "MAKE YOUR OWN
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Designers sometimes feel this way#
An exercise in biomaterials design:
!! Select an implant
!! Define the relevant properties
!! Define the material
!! Propose the processing technique
!! For what application could it be used
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But you have to use the proper material and design it properly!
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Hey, let‘s have a break and think about it again!
Wear parts
Load-bearing parts Defect fillers Issues to be considered