4. 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.
8. Nucleic Acids
• Large and complex organic molecules that
store and transfer genetic information in the
cell
• Types of nucleic acids
i. DNA =deoxyribonucleic acid
ii. RNA = Ribonucleic acid
9. Building blocks of Nucleic Acids
• Monomers of nucleic acids are nucleotides
• Components of a nucleotide
- nitrogen base
- sugar
- phosphate
11. Ribonucleic acid (RNA)
• Is a single helix
• Can be found in the
nucleus and the
cytoplasm of the cell
• Helps build proteins
• Can act as an
enzyme
12.
13.
14. Polypeptide
• A long chain of amino
acids…POLYPEPTIDE
• Proteins are composed
of one or more
polypeptides
15. Amino Acid Structure
R Groups of amino acids
• Difference in amino acids…….. R groups
• R group……simple or complex
• R groups…different shapes & characteristics
16. Peptide bond
-COOH group of one amino acid joined with the -NH2
group of the next amino acid through condensation
polymerization
18. Proteins
• Polymers of amino acids covalently linked
through peptide bonds
• Natural organic molecules….C, H, O, N
• Monomers…….amino acids
19. Building blocks of proteins
• There are 20 different amino acids
• All 20 amino acids share the same basic structure
• Every amino acid contains
- an amino group
- a carboxyl group
- a hydrogen atom
- a central carbon atom
- R (alkyl/aryl) group
20. Role of Proteins
• Structural roles…….cytoskeleton
• Catalysts……enzymes
• Transporter………ions and molecules
• Hormones
• Many enzymes are proteins
• Biological catalysts
• Lower the activation energy of chemical
reactions
• Increase the rate of chemical reactions
24. Lipids
• Large, nonpolar organic molecules
• LIPIDS do NOT Dissolve in Water!
• Have a higher ratio of carbon and hydrogen
atoms to oxygen atoms than carbohydrates
• Lipids store more energy per gram than other
organic compounds
25. Categories of Lipids
• Fatty Acids
• Triglycerides
• Phospholipids
• Waxes and Oils
• Steroids
26. Fatty Acids
• Linear carbon chains
• On one end of the carbon chain is a carboxyl
group
• On the other end of the carbon chain is a methyl
group
27. Fatty acid chain
• The carboxyl end is polar and is hydrophilic
• The carboxyl end will dissolve in water
• The methyl end is nonpolar and is hydrophobic
• The methyl end will not dissolve in water
29. Triglycerides
One molecule of glycerol and three fatty acid chains
Saturated triglycerides…butter, fats and red meat
Unsaturated triglycerides….plant seeds
34. Carbohydrates are organic compounds
1C:2H:1O
Source of energy……..sugars
Store of energy………..starch
Structural materials….polysaccharides
Components of other molecules e.g. DNA, RNA,
glycolipids, glycoproteins
36. Monosaccharide
Single monomer of carbohydrate….glucose
Simple sugar
1C:2H:1O
A source of quick energy
Glucose – main source of energy
Fructose – fruits sugar/sweetest
sugar
Galactose – milk sugar
Common MonosacchArides
39. Disaccharides
• “Di” means two
• Two monosaccharides combine
• Common Disaccharides are
- Lactose (found in milk)
- Maltose
- Sucrose (table sugar)
Maltose
Sucrose Lactose
42. is a long-chain polymer of an
N-acetyl glucosamine.
a derivative of glucose, and is found
in many places throughout the
natural world.
It is a characteristic component of
the cell walls of fungi,
the exoskeletons of arthropods such
as crustaceans and insects, and
other living cell organisms
Chitin
A close-up of the wing of a sap
beetle; the wing is composed
of chitin
43. Chitin is a modified polysaccharide that contains nitrogen
it is synthesized from units of N-acetylglucosamine
(to be precise, 2-(acetylamino)-2-deoxy-D-glucose).
These units form covalent β-1,4 linkages, (similar to the linkages
between glucose units forming cellulose).
Therefore, chitin may be described as cellulose with
one hydroxyl group on each monomer replaced with
an acetyl amine group.
This allows for increased hydrogen bonding between
adjacent polymers, giving the chitin-polymer matrix increased
strength.
In its pure, unmodified form, chitin is translucent, pliable, resilient,
and quite tough.
In most arthropods, however, it is often modified, occurring largely
as a component of composite materials, such as in sclerotin, a
tanned proteinaceous matrix, which forms much of the
exoskeleton of insects.
44. Combined with calcium carbonate, as in the shells
of crustaceans and molluscs, chitin produces a much stronger
composite. This composite material is much harder and stiffer than
pure chitin, and is tougher and less brittle than pure calcium
carbonate.
Another difference between pure and composite forms can be seen by
comparing the flexible body wall of a caterpillar to the stiff,
light elytron of a beetle (containing a large proportion of sclerotin ).
•USES
Chitin can be used in many different branches of:
•Agriculture
•Medicine
•Industry
•Biomedical researchs
45. Keratin filaments are abundant in keratinocytes in
the cornified layer of the epidermis; these are proteins which
have undergone keratinization.
In addition, keratin filaments are present in epithelial cells in
general. For example, mouse thymic epithelial cells (TECs)
are known to react with antibodies for keratin 5, keratin 8,
and keratin 14. These antibodies are used as fluorescent
markers to distinguish subsets of TECs in genetic studies of
the thymus.
Silk fibroin, considered a β-keratin( glycine and alanine 75–
80% of the total, with 10–15% serine, with the rest having
bulky side groups) The chains are antiparallel , with an
alternating C → N orientation
Keratın
46. the α-keratins in
the hair (including wool), horns, nails, claws and
hooves of mammals.
the harder β-keratins found in nails and in
the scales and claws of reptiles,
their shells (Testudines, such
as tortoise, turtle, terrapin), and in
the feathers, beaks, claws of birds and quills of
porcupines. Horns such as those
of the impala are
made up of keratin
covering a core of
live bone.
47. a translucent, colorless, brittle flavorless food derived
from collagen obtained from various animal by-products.
Gelatin is an irreversibly hydrolyzed form of collagen.
Substances containing gelatin or functioning in a similar way
are called "gelatinous".
Gelatin is a mixture of peptides and proteins produced by
partial hydrolysis of collagen extracted from the skin, bones,
and connective tissues of animals such as domesticated
cattle, chicken, pigs, horses, and fish.
Gelatin readily dissolves in hot water, and sets to a gel on
cooling and in most polar solvent.
The mechanical properties of gelatin gels are very sensitive to
temperature variations.
The upper melting point is below human body temperature.
gelatıne
48. The worldwide production amount of
gelatin is about 375,000 metric tons per
year.
On a commercial scale, gelatin is made
from by-products of the meat and leather
industries.
The procedure of produce gelatin have
many steps which are : pretreatment,
extraction, recovery.
49. Culinary uses : different types and
grades of gelatin are used in a wide
range of food and nonfood products
( gelatin desserts).
Technical uses :
•Hide silver halides.
•Gelatin is closely related to bone glue and is used as a
binder in match heads and sandpaper.
•Cosmetics may contain a nongelling variant of gelatin
under the name hydrolyzed collagen.
•Drugs capsules.
And other uses
52. Biomaterials
Any material used to make devices to replace a part or a
function of the living body in a safe, reliable, economic
& physiologically acceptable manner
OR
Any material used to replace part of a living system or to
function in intimate contact with living tissue
OR
A pharmacologically inert substance designed for
implantation within or incorporation with living system
Natural/synthetic/blend
e.g. sutures, tooth fillings, bone replacements, artificial
eyes etc.
58. Natural Polymers as Biomaterials
Polymers derived from living creatures
“Scaffolds” grow cells to replace damaged
tissue
• Biodegradable
• Non-toxic
• Mechanically similar to the replaced tissue
• Capable of attachment with other molecules
Natural polymers used as biomaterials
– Collagen, Chitosan and Alginate
59. Collagen
• Consist of three intertwined
protein chains, helical structure
• Collagen…..non-toxic , minimal
immune response
• Can be processed into a variety
formats
– Porous sponges, Gels, and Sheets
• Applications
– Surgery, Drug delivery, Prosthetic
implants and tissue-engineering of
multiple organs
60. Chitosan
• Derived from chitin, present in hard exoskeletons
of shellfish like shrimp and crab
• Chitosan desirable properties
– Minimal foreign body reaction
– Mild processing conditions
– Controllable mechanical
– biodegradation properties
• Applications
– In the engineering of cartilage, nerve, and liver tissue,
– wound dressing and drug delivery devices
61. Alginate (ALGINIC ACID)
• A polysaccharide derived
from brown seaweed
-Can be processed easily in
water
-non-toxic
-Biodegradable
-controllable porosity
• Forms a solid gel under mild
processing conditions
• Applications in
Liver, nerve, heart, cartilage
& tissue-engineering
62. Synthetic Polymers as Biomaterials
• Advantages of Synthetic Polymers
– Ease of manufacturability
– process ability
– reasonable cost
• The Required Properties
– Biocompatibility
– Sterilizability
– Physical Property
– Manufacturability
• Applications
– Medical disposable supplies, Prosthetic materials, Dental
materials, implants, dressings, polymeric drug delivery,
tissue engineering products
63. Biodegradable Polymers as Biomaterials
• Advantages on biodegradable polymer
– Didn’t leave traces of residual in the implantation
– Regenerate tissue
• Desirable properties are
- greater hydrophilicity
- greater reactivity
- greater porosity
Most widely used
Polylactide (PLA), Polyglycolide (PGA), Poly(glycolide-co-
lactide) (PGLA)
Applications
Tissue screws, suture anchores, cartilage repair
Drug-delivery system
65. Biocompatibility of biomaterials
• The ability of a material to elicit an
appropriate biological response in a specific
application without producing a toxic,
injurious, or immunological response in living
tissue
– Strongly determined by primary chemical structure
• When an object is incorporated into the body
without any immune responses it is said to be
BIOCOMPATIBLE
66. Standardization of Biomaterials
FDA (united states food and drug administration)
Biocompatibility tests
• acute systemic toxicity………denoting the part of circulatory
system
• Cytotoxicity…….toxic in living cell
• Haemolysis….dissolution of erythrocytes in blood
• Intravenous toxicity
• Mutagenesis….permanent genetic alteration
• Oral toxicity
• Pyrogenicity….products produced by heat
• Sensitization…making abnormally sensitive
67. Guidance on biocompatibility assessment
Material characterization
• Chemical structure of material
• Degradation products
• Residue level
Toxicological data
• Biological tests based on clinical trial
68. Guidance on biocompatibility assessment
Supporting documents
• Details of application…shape, size, form, contact time
etc.
• Chemical breakdown of all materials involved in the
product
• A review of all toxicity data
• Prior use and details of effects
• Toxicity standard tests
• Final assessment including toxicological significance
69. Types of biomaterials based on surgical
uses
Muscular skeletal system…joints in
upper & lower extremities & artificial
limbs
Permanent implants
Cardiovascular system …valve,
pacemaker, arteries, veins
Digestive system…tooth filling,
oesophagus, bile duct
Nervous system…. Dura, hydrocephalus
shunt
Cosmetic implants…..nose, ear, teeth, eye
70. Types of biomaterials based on surgical
uses
Transient implants
Extracorporeal assumption of organ
function….heart, lung , kidney
Orthopaedic fixation devices….screw,
hip pins, bone plates, suture, surgical
adhesives
External dressings & partial
implants….artificial skin, immersion
fluids
Aids to diagnosis….catheters, probes
71. Performance of Biomaterials
• Fracture
• Loosening
• Infection
• Wear
r = 1-f
r is reliability of implant
f is failure
72. Future challenges
• To more closely replicate complex tissue
architecture and arrangement in vitro.
• To better understand extracellular and
intracellular modulators of cell function.
• To develop novel materials and processing
techniques that are compatible with biological
interfaces
• To find better strategies for immune
acceptance
