A biomaterial is any substance engineered to interact with biological systems for medical purposes like therapy or diagnosis. There are three main groups of biomaterials used for tissue engineering: bioceramics, biopolymers, and composites. Bioceramics include bioinert materials like zirconia and alumina, bioactive materials like bioglass and hydroxyapatite that bond with tissue, and biodegradable materials like calcium phosphates. Biopolymers can be natural materials like collagen and chitosan or synthetic polymers like polylactic acid and polypropylene. Composites combine synthetic and natural polymers or polymers with metals to achieve biocompatibility and mechanical properties for applications

1. Introduction to potential
Biomaterials

2. Biomaterial
A biomaterial is any substance that has been engineered to interact with
biological systems for a medical purpose - either a therapeutic (treat,
augment, repair or replace a tissue function of the body) or a diagnostic
one.
Material intended to interface with biological systems to evaluate, treat,
augment or replace any tissue, organ or function of the body

3. Material Selection Parameters
 Should be biologically active(hydrophilic in nature so that cell will be attached)
 Sterilizable- without property loss (to prevent contamination)
 Mechanical strength (withstand shear stress generated by biological fluid flow)
 Biocompatible (should not involve any underisable reaction)
 Biodegradable (should not give harmful effect)
Typically three individual groups of biomaterials are used in the fabrication of scaffolds
for tissue engineering

4. Bioceramics
The class of ceramics used for repair and replacement of diseased and damaged parts of
the musculoskletal system are referred to as bioceramics.
They are important subset of biomaterials.
Properties:
 Usually inorganic
 Highly inert
 Hard and brittle
 High compressive strength
 Generally good electric and thermal insulators
 Good aesthetic appearance

5. Bioinert
■ Bioinert materials are ones which do not initiate a response or interact when introduced to
biological tissue. In other words, introducing the material to the body will not cause a
reaction with the host. Maintain their physical and mechanical properties while in host.
■ Resist corrosion and wear.
■ Examples
■ Zirconia
■ Alumina

6. Bioactive
Direct and strong chemical bond with tissue.
■ Fixation of implants in the skeletal system.
■ Low mechanical strength and fracture toughness.
■ Examples: Bioglass , Hydroxyapatite

7. Biodegradable
■ Chemically broken down by the body and degrade.
■ The resorbed material is replaced by endogenous tissue.
■ Chemicals produced as the ceramic is resorbed must be able to be processed through the normal
metabolic pathways of the body without evoking any deleterious effect.
■ Synthesized from chemical (synthetic ceramic) or natural sources (natural ceramic).
Examples
calcium phosphates are the major representatives of Crystalline Ceramics that are among the most widely
used crystalline This is due to their exceptional properties that include
■ (i) similarity, in terms of structure and chemical composition, to the mineral phase of bone, and
■ (ii) osteoconductivity, i.e., the ability of providing a biocompatible interface along with bone migrates,
■ and thus bonds to the host tissue without the formation of scar tissue

8. Biopolymers
■ Biopolymers are polymers produced by living organisms; in other words, they are
polymeric biomolecules. Since they are polymers, biopolymers
contain monomeric units that are covalently bonded to form larger structures.
■ Two types:
1. Natural polymer
■ The natural polymer is produced by living organisms and result from only raw
materials that are found in nature
 Natural materials are readily recognized by cells.
 Interactions between cells and biological ECM are catalysts to many critical
functions in tissues

9. Examples
■ Collagen
 They are non toxic in nature
 They offer minimum immune response
■ Chitosan
 They have minimal foreign body rejection
 They have controllable mechanical/biodegradation properties
 Usuallu used in nerve, liver tissue
■ Alginate
■ It is non-toxic, biodegradable

10. Synthetic polymers
■ More controllable from a compositional and materials processing viewpoint.
■ Scaffold architecture are widely recognized as important parameters when
designing a scaffold
■ They may not be recognized by cells due to the absence of biological signals.
■ Examples
 Polylactic acid
it degrades within the human body to form lactic acid, a naturally occuring
chemical which is easily removed from the body

11.  Polypropylene (PP)
It has a high tensile strength and excellent stress-cracking resistance.
Used in artificial vascular grafts
 Polymethyl metacrylate
It is Resistant to inorganic solutions and has excellent optical properties.
It is used in Blood pump and reservoir, implantable ocular lenses, and bone cement.

12. Composites
■ A Composite material is a material made from two or more constituent materials
with significantly different physical or chemical properties
■ Usually mixture of synthetic and natural polymer
■ Generally biocompatible, show excellent mechanical properties and are useful for
orthopedic and dental prosthetics
Examples
Silk
Metals

13. ■ Stainless steel is used for internal fixation device because of mechanical properties,
corrosion resistance
■ Co-Cr alloys are most commonly used to make artificial joints including knee and hip joints
due to high wear-resistance and biocompatibility.