5. What is a Biomaterial?
A biomaterial is a nonviable material used in a medical
device, intended to interact with biological systems
(Williams, 1987)
[OR]
Any material of natural or of synthetic origin that
comes in contact with tissue, blood or biological fluids,
and intended for use in prosthetic, diagnostic,
therapeutic or storage application without adversely
affecting the living organism and its components.
6. This is how the Biomaterials reacts when placed in the
damaged parts of Human
9. BIOMATERIALS APPLICATION INCLUDES
- Physical scientists
- Engineers
- Dentists
- Biological scientists
- Surgeons
- Veterinary practitioner in Industries grove
- Clinical specialties and academic settings
10. Need for biomaterials
● Millions of patients suffer end stage organ and tissue
failure annually.
– $400 billion annually for treatment. – 8 million
surgical procedures.
● Treatment options include transplantation,
reconstruction, mechanical devices.
11. Background
● Historically, biomaterials consisted of materials
common in the laboratories of physicians, with little
consideration of materials properties.
● Early Biomaterials:
– Gold: Malleable, inert metal (does not oxidize), used in
dentistry.
– Iron, Brass: High Strength Metals, rejoin fractured
femur
– Glass: Hard ceramic, used to replace eye [cosmetic]
– Wood: Natural composite, high strength to weight,
used for limb prostheses.
– Bone: Natural composite.
13. First Generation Biomaterials
● Ad-hoc’ (unplanned) Implants
● Specified by physicians using common and borrowed
materials.
● Requirements were to find a suitable physical
properties to match those of the replaced tissue with a
minimal toxic response of the host, so biologically
inert or nearly inert materials were used in order to
reduce the corrosion and to minimise the immune
response and foreign body reaction.This is known as
“Bioinertness”
14. ● Examples
– Gold fillings, wooden teeth, PMMA dental prosthesis
– Steel, gold, ivory, bone plates etc.
– Glass eyes and other body parts
• Great success of the first generation of biomaterials in
orthopedic area is the total hip replacement.
• Inert polymeric materials developed in the first
generation of biomaterials, are polyethylene,
polyurethane, polypropylene, and silicone rubbers.
• Currently these materials are used in temporary
implants.
15. Second Generation of Biomaterials
● Engineered implants using common and borrowed
materials.
● Developed through collaborations of physicians and
engineers.
Bioactivity: A bioactive material is one that elicits a
specific biological response at the interface of the
material, which results in the formation of a bond
between tissues and the material.
Examples:
-Heart valves and Pacemakers.
16. Third Generation of Biomaterials
• Introduces the idea of Regenerative medicine.
• Biomaterials are capable of stimulating one or several
functions of the cells forming tissues (bone, muscle,
cartilage) rough proper signaling, to stimulate the
regeneration of this tissue.
• Examples:
-Cell matrices for 3-D growth and tissue reconstruction.
• Tissue engineering involves the use of molecular and cell
biology technology, combining the advantages of
materials science and processing in order to produce
tissue regeneration in situations where the patient׳s cells
lack the capacity to regenerate over time.
17. General criterion for biomaterial selection
● Mechanical and chemicals properties.
-strength, elastic modulus,fatigue strength, wear
resistance, corrosion resistance.
● No undesirable biological effects – carcinogenic,
toxic, allergenic or immunogenic.
● Possible to process, fabricate and sterilize with a
good reproducibility.
● Acceptable cost/benefit ratio.
18.
19. Metallic biomaterials
• Metallic biomaterials are used almost exclusively for
load bearing applications
-Knee or hip implants, dental implants, fracture
fixation.
• Due to their excellent high strength, fracture toughness,
relative ease of fabrication, good electrical conductivity
made them to use in various applications.
• Most commonly use metallic biomaterials are
1.Stainless steels(alloy of Ni, Fe, Cr, Mn) (316L grade –
better corrosion resistance)
2.Cobalt-chromiumMolybdenum(COCRMO or CMM).
3.Titanium (Ti) or Ti alloys (Ti6Al4V is a very common
variant)
20. Bio ceramics
• Bioceramics are “specially designed and fabricated
ceramics which can be used to repair and reconstruct
the diseased, damaged or “worn out” parts of the
body.
• The resistance to
-Micro organisms,
-Temperature,
-Solvents,
-pH changes,
-High pressures is the advantage in health and dental
applications.
21. Alumina -Al2O3
Alumina as biomaterial was introduced in 1970 successfully as
an alternative for metallic alloys.
Advantages:
• High hardness and wear resistive property,
• Low coeff of friction,
• Excellent corrosion resistance,
• High chemical stability
• Bioinert,
•Non toxic to human body
Limitations:
• Intrinsic brittleness • Higher fracture rate
• Minimal bone ingrowth • Non-adherent fibrous membrane
• Interfacial failure and loss of implant can occur
22. • Orthopaedics: • Dental:
- bone screws and plates -crowns
-porous coatings for femoral stems -bridges
-porous spacers
- knee prosthesis
Zirconia as Bioceramic
1. High Fracture Toughness,
2.Hardness and Wear resistance
3.Use temperatures up to 2400°C
4.Low thermal conductivity (20% that of alumina)
5.Less Toxic, Chemically inert
6. Allows larger Range of Design,
23. 7.Dimensionally stable
8.Lower modulus of elasticity and higher strength
9.Better bending strength
Applications:
• Orthopaedics:
Total & partial hip and knee replacement components,
artificial knee,bone screws and plates.
• Dental: crowns and bridges
• Coatings (of metal prostheses) for controlled
implant/tissue interfacial response
• Space filling of diseased bone
24. Calcium Phosphate
-Bio degradable
- Structure resembles bone mineral; thus used for
bone replacement
- Coating of metal implants to promote bone
ingrowth.
- Used in the form of:
• Powders
• Scaffolds
• Coatings for implants – metals, heart valves to
inhibit clotting
• Self-Setting bone cement
26. Polymeric Biomaterials
A polymer is large molecule(macromolecule) composed
of many repeated subunits called monomers.
-Natural polymers and their derivatives are commonly
used in medicines and pharmacy.
-Particular attention has recently been paid to natural
polymers, because they are biocompatible and
biodegradable, so they can be hydrolized into
removable and non toxic products.
- Examples:
- Polymethylmethacrylate(PMMA),Polyvinyl-
chloride(PVC),Polypropylene(PP),Polystyrene.
29. HOW THE HOST REACTS TO BIOMATERIALS
THROMBOSIS
HEMOLYSIS
INFLAMMATION
INFECTION AND STERILIZATION
CARCINOGENESIS
HYPERSENSITIVITY
SYSTEMIC EFFECTS
These are the various effect occurs when the host
reacts with a Biomaterial.
30. APPLICATIONS OF BIOMATERIALS
- Therapeutic devices
- Dentistry
- Cardiovascular system
- Ophthalmology
- Drugs delivery
- Cosmetic applications
- Medical devices
32. 3. bone cement -PMMA
4.Heart valve -carbon,reprocessed
tissue.
33.
34. Conclusions
• With time metallic biomaterials applications are
replacing with bioceramics.
• Development of material sciences helped in making
materials having comparable properties with human
body.
• Every day thousands of surgical procedures are
performed to replace or repair tissue and thus field of
tissue engineering (TE) aims to regenerate damaged
tissues is a great challenge and most advanced field.
35. References
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pp. 363–366.
3. J.B. Park, J.D. Bronzino,Biomaterials: Principles and Applications, CRC Press, Boca Raton (2003).
4. L.L. Hench Bioactive materials, Ceram. Int., 22 (6) (1996), pp. 493–507.
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7. D.H. Hutmacher, J.T. Schantz, K.C. Tan, T.C. Lim,State of the art and future directions of scaffolds-
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