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BIOMATERIALSENT 311/4
Course overview
Prepared by: Nur Farahiyah Binti Mohammad
Date: 7th July 2008
Email : [email protected]
2
Course structure
Course code: ENT 311/4 Lecturer: Miss Nur Farahiyah Mohammad Mr Nashrul Fazli Mohd Nasir Teaching Engineer: Miss Adilah Hashim Course synopsis Course outcome 12 topics Lesson plan
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Course assessment
Final Exam : 50% Test/Quiz : 10% Lab assessment : 30% Assignment : 10% 100%
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List of text book and references
Text book:1. Buddy D. Ratner, Allan S. Hoffman, Frederick J. Schoen & Jack E.
Lemons. Biomaterials Science: An Introduction to Materials in Medicine. 2nd Ed., Elsevier Academic Press, 2004.
2. Johnna S. Temenoff and Antonios G. Mikos. Biomaterials: The Intersection of Biology and Materials Science. Prentice Hall, 2008.
Reference book:1. Joon B. Park & Joseph D. Bronzino. Biomaterials: Principles and
Applications, CRC Press, 2002. 2. Joyce Y. Wong & Joseph D. Bronzino. Biomaterials, CRC Press, 2007.3. Joon B. Park & Roderic S. Lakes. Biomaterials: An Introduction, 2nd
Ed., Plenum Press, 1992.4. Sujata V. Bhat. Biomaterials, 2nd Ed., Alpha Science International
Ltd, 2005.5. Donglu Shi. Biomaterials and tissue engineering, Springer, 2004.
Lecture 1: Introduction to Biomaterials
BIOMATERIALSENT 311/4
Prepared by: Nur Farahiyah Binti Mohammad
Date: 7th July 2008
Email : [email protected]
6
Objective
Define biomaterials Describe biomaterial applications Define and describe biocompatibility
principle Explain factors contribute to the
performance of biomaterials in the body.
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What is it biomaterial?
A material intended to interface with biological systems to evaluate, treat, augment, or replace any tissue, organ or function of the body (Williams, 1999).
Any substance (other than drugs) or combination of substance , synthetic or natural origin, which can be used for any period of time, as a whole or as a part of a system which treats, augments, or replace any tissue, organ or function of the body (Williams, 1987).
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A biomaterial is any material, natural or man-made, that comprises whole or part of a living structure or biomedical device which performs, augments, or replaces a natural function" (Wikipedia).
“A systemically and pharmacologically inert substance designed for implantation within or incorporation with living system” (The
Clemson University advisory Board for Biomaterials).
What is it biomaterial?
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Biomaterial Application in Human Body
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Biomaterials history
Year Development
Late 18th–19th century
1860-1870
Early 1900
Various metal device to fix bone fracture: wire and pins from Fe(Iron), Au (gold), Ag(silver), Pt (platinum)
Aseptic surgical units(The use of biomaterials did not become practical until the advent of an aseptic surgical technique develop by Dr J. Lister.)
Bone plates were introduced to aid in fixation of long bone fracture. However, many of these early plates broke due unsophisticated mechanical design; -too thin -Had stress concentrating corners. -Corrode rapidly in the bodyIntroduction of stainless steel and cobalt chromium alloys
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Biomaterials history
Year Development
1930s
1938
1940s
1946
1950s
1960s
Introduction of stainless steel and cobalt chromium alloys
First total hip replacement prosthesis.
First used polymethyl methacrylate (PMMA) for corneal implant and replacement of section of damaged skull bone. (During World War II shattered perspex in pilots didn’t cause problem.)
First biomechanically designed femoral head replacement prosthesis: first plastic (PMMA) used in joint replacement.
First successful blood vessel replacement
First commercial heart valve replacementCemented joint replacement
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Current status of the field
Today, biomaterials represent a significant portion of the healthcare industry, with an estimated market size of over $9 billion per year in the United States.
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Cardiovascular area: approximately 100,00
replacement heart valves and 300,000 vascular graft implanted per year in US.
Artificial joints replacements: Over 500,000 artificial joint
replacements, such as knee or hip, are implanted yearly in United States.
Current status of the field
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Future Directions
Starting 1960s-1970s The first generation of biomaterials was
designed to be inert, or not reactive with the body
Decreasing the potential for negative immune response to the implant.
In 1990’s until now Materials designed to be bioactive,
interacting in positive manner with the body to promote localized healing.
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Development of “smart” material which can help guide the biological response in the implant area.
Design of injectable materials that can applied locally and with minimal pain to the patient.
New set of nano-structured biomaterials for nano-scale objects as reinforcing agents.
Future Directions
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Application of Biomaterials
Biomaterials that will be used may be considered from the point of view of the problem area that is to be solved:
Problem Area Examples
Replacement of diseased or damaged part
Assist in healing
Improve function
Correct functional abnormality
Correct cosmetic problem
Aids to diagnosis
Aid to treatment
Artificial hip joint, kidney dialysis machine
Sutures, bone plates, and screws
Cardiac pacemaker, intraocular lens, cochlear implant
Cardiac pacemaker
Breast implant, soft tissue augmentation, chin augmentation
Probes, catheter
Catheters, drains
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Application of Biomaterials
Biomaterials that will be used may be considered from the point of view of the organ that will need to be replaced or improve:
Organ Heart
Heart
LungEyeEarBoneKidneyBladder
Cardiac pacemaker, artificial heart valve, total artificial heartOxygenator machineContact lens, intraocular lensCochlear implantBone plate, screwKidney dialysis machineCatheter and stent
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Biomaterials are classified as: Organic if contain carbon Inorganic if they do not.
More specifically biomaterials fall into one of three of materials: Metals (inorganic material) Ceramics(inorganic material) Polymers (organic material)
Type of Biomaterials
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Type of Biomaterials
Biomaterials
Inorganic Organic
Metals Ceramics Polymers
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Type of Biomaterials
Materials Advantages Disadvantages Examples
PolymersNylon,Polyethylene,Silicone, Teflon,Dacron,Acrylates,PGA, PLA
Resilient,Easy to fabricate
Not Strong, Deforms with time, may degrade
Sutures, vascular graft, hip socket, intraocular lenses
Metals(Titanium and its alloys, Co-Cr alloys, stainless steel,Gold)
Strong, Tough,Ductile
May corrode,Dense,Difficult to make
Joint replacement,Bone plates and screws, Dental root implant
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Type of Biomaterials
Materials Advantages Disadvantages Examples
CeramicsAluminum oxide, Calcium phosphates,Carbon
Very biocompatible,Inert,Strong in compression
Brittle,Not resilient, Difficult to make
Dental implant, Femoral head of hip replacement,Coating of dental and orthopedic implants
CompositesCarbon-carbonCeramic-polymer
Strong, less stiff than metals,Strong in compression
Difficult to make,Weak in tension
Joint implantsDental fillings
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Performance of biomaterials
The success of biomaterials in the body depends on factors such as: Material properties Design of the implants Biocompatibility of the materials Technique used by the surgeon Health and condition of the patient Patient activities
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The Concept of Biocompatibility
Definition of biocompatibility:
“Biocompatibility is the ability of a material to perform with an appropriate host response in a specific application” (William, 1987).
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The Concept of Biocompatibility
Biocompatibility characteristic: Biocompatibility involves the acceptance
of an artificial implant by the surrounding tissues and by the body as a whole.
Biocompatible materials Do not irritate the surrounding structures Do not provoke an abnormal inflammatory
response Do not incite allergic or immunologic reactions Do not cause cancer
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The Concept of Biocompatibility
Biocompatible materials have adequate mechanical properties.
Biocompatible materials have appropriate optical properties (eye).
Biocompatible materials have appropriate density.
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The End
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Supplementary slide
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Course synopsis
This course is designed to provide a basic knowledge of biomaterials and to provide understanding of interactions between physiological components and biomaterials.
Ranges of materials currently being utilized for various biomedical applications and their biocompatibility with references to the biological responses and environments available will be discussed.
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Course Outcomes
CO1:Ability to describe the concept of biocompatibility and basic concepts of materials used in medical application.
CO2: Ability to explain and evaluate the biocompatibility of biomaterials utilized as implants or contact devices with human tissues.
CO3:Ability to explain and illustrate tissue reactions to biomaterials.
CO4:Ability to select biomaterials that can be used for different medical applications and explain the criteria that will lead to a successful implants.
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Examples of Biomaterials application
Artificial hip joint Needed because natural joint
wear out. Replacement hip joint are
implanted in more than 90 000 humans each year in US.
Fabricated from titanium, ceramics, composite, UHMWPE.
After 10-15 years, the implant may loose, require another operation.
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Examples of Biomaterials application
Prosthetic Heart valve
Fabricated from carbon, metal, elastomers, fabrics, natural valves and tissue chemically pre-treated.
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Show good performance as soon as the valve is implanted but have some problems: Degeneration of tissue Mechanical failure Postoperative infection Induction of blood cloth
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Examples of Biomaterials application
Intraocular lenses (IOL) Used to replace a natural lense
when it become cloudy due to cataract formation.
Fabricated of poly (methyl methacrylate), silicone elastomer, soft acrylic polymers or hydrogels.
Complication: IOL stimulate outgrowth cells from the posterior lens capsule → cloud the vision.
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Week Content / Lecture Topic
Week 1 Introduction to Biomaterials
Week 2 Properties of biomaterials
Week 3 Polymeric Biomaterials
Week 4 Metallic Biomaterials
Week 5 Ceramic Biomaterials
Week 6 Tissue Reaction to Biomaterials
Week 7 Semester Break
Week 8 Tissue Reaction to BiomaterialsMid Semester Test
Week 9 Biological Testing of Biomaterials
Week 10 Blood Contacting Implant
Week 11 Non-blood Interfacing Implant
Week 12 Hard Tissue Replacement: Internal Fixation and Joint Replacement
Week 13 Special Break
Week 14 Hard Tissue Replacement: Internal Fixation and Joint Replacement
Week 15 Tissue Engineering
Week 16 Scaffolds for Tissue EngineeringAssignment Presentation
Week 17 Revision week
Week 18-20 Final Examination