Biomaterials are natural or synthetic substances engineered to interact with biological systems, often in medical applications, to replace, augment, or repair damaged tissues or bodily functions. These materials, which can be metals, ceramics, polymers, or composites, are designed to be biocompatible, meaning they can interface with living tissue without causing adverse reactions. They are crucial for various applications, including prosthetics, drug delivery systems, and tissue engineering.

1. Biomaterials
Presentation by Sanju Sah
St. Xavier's College, Maitighar
Kathmandu, Nepal

2. Introduction to Biomaterials
• • Biomaterials are materials designed to
interface with biological systems for medical
purposes, such as therapeutic or diagnostic
applications.
• • Can be derived from natural sources or
synthesized through chemical processes.
• • Must exhibit biocompatibility, mechanical
integrity, and specific biological responses to
function effectively in vivo.
• • Research involves studying material-tissue

3. Types of Biomaterials
• • Metals: High mechanical strength; used in
load-bearing implants (e.g., Ti-6Al-4V, Co-Cr
alloys). Require surface treatments to improve
biocompatibility.
• • Ceramics: Inert or bioactive materials such
as hydroxyapatite, used in bone regeneration
and dental applications.
• • Polymers: Can be biodegradable (e.g., PLGA)
or non-biodegradable (e.g., silicone). Tailored
for drug delivery, scaffolds, or prosthetics.

4. Applications of Biomaterials
• • Orthopedic Implants: Joint replacements,
bone plates, screws. Require wear resistance
and osseointegration.
• • Dental Implants: Must integrate with
jawbone and resist oral bacterial colonization.
• • Cardiovascular Devices: Stents, vascular
grafts, heart valves; must endure
hemodynamic forces and prevent thrombosis.
• • Tissue Engineering: Scaffold materials
promoting cell adhesion, proliferation, and

5. Future of Biomaterials
• • Smart Biomaterials: Respond to
environmental stimuli (pH, temperature,
enzymes) for dynamic therapeutic functions.
• • Bioinspired and Biomimetic Materials: Mimic
natural ECM or biological systems to enhance
integration and function.
• • Bioprinting: 3D printing of scaffolds with
cells and bioactive factors for personalized
tissue fabrication.
• • Immunomodulatory Biomaterials: Designed

6. Ceramic Biomaterials
• Ceramics are inorganic, non-metallic materials
that are typically brittle but chemically stable.
Common ceramic biomaterials include
hydroxyapatite, alumina, and zirconia. These
materials are often used in bone and dental
applications due to their biocompatibility, high
compressive strength, and ability to bond
directly with bone (bioactivity).
Hydroxyapatite mimics the mineral

7. Composite Biomaterials
• Composites are combinations of two or more
constituent materials with differing properties
to produce a material with characteristics
superior to the individual components. In
biomaterials, common composites include
polymer-ceramic or polymer-metal matrices.
They are used in orthopedic and dental
applications for improved mechanical strength
and bioactivity. The interface between

8. Biomaterials by Biocompatibility
and Biodegradability
• Biomaterials can be classified based on
biocompatibility (how well a material
integrates with biological tissue without
causing an adverse reaction) and
biodegradability (ability to degrade in the
body over time).
• - Biocompatible: Titanium, polyethylene
• - Non-biocompatible: Certain heavy metals

9. Recent Developments and Legal
Issues
• Recent advancements include smart
biomaterials that respond to stimuli,
immunomodulatory materials, and AI-
integrated biosensing systems. Legal issues
concern regulatory approvals (FDA, EMA),
intellectual property rights, and liability for
adverse outcomes. Ethical concerns include
patient consent, transparency in clinical trials,
and equitable access to new technologies.

10. Nanomaterials for Drug Delivery
• Nanomaterials (e.g., liposomes, dendrimers,
polymeric nanoparticles) are designed to
deliver drugs with high precision. Benefits
include enhanced bioavailability, targeted
delivery, reduced side effects, and controlled
release. Surface functionalization allows
targeting specific cells or tissues. Challenges
include toxicity, immune responses, and
regulatory approval.

11. Corrosion of Biomaterials
• Corrosion refers to the degradation of metals
in physiological environments. Stainless steel,
cobalt-chromium, and titanium alloys can
corrode due to pH variations and body fluids,
leading to metal ion release, which may
trigger inflammatory responses or toxicity.
Surface coatings and alloying improve
corrosion resistance.

12. Fatigue, Fracture, Brittle to Ductile
Transition
• - Fatigue: Repeated stress cycles causing
microscopic cracks and eventual failure.
Important in load-bearing implants.
• - Fracture: Sudden material breakage;
influenced by defects, loading rate, and
temperature.
• - Brittle to Ductile Transition: A shift from
brittle to ductile behavior with increased
temperature; vital in assessing implant

13. Biopolymers or Biomedical
Polymers
• Biopolymers are naturally derived or synthetic
polymers used in medicine, such as PLA, PGA,
and PEG. Applications include sutures, drug
delivery carriers, and scaffolds. Properties like
degradability, elasticity, and hydrophilicity are
tailored for specific uses.

14. Collagen as Biomaterial
• Collagen is a natural protein forming part of
the extracellular matrix. It's biocompatible,
biodegradable, and promotes cell adhesion.
Widely used in wound healing, tissue
engineering, and cosmetic applications. Can
be modified chemically or physically for
enhanced mechanical properties.

15. Cellulose and Its Derivatives
• Cellulose is a plant-derived polysaccharide
used for wound dressings, drug delivery, and
scaffolding. Derivatives like carboxymethyl
cellulose (CMC) and hydroxypropyl cellulose
(HPC) enhance solubility and processability.
Biocompatible and biodegradable.

16. Tissue Engineering and Scaffolds
• Tissue engineering combines cells, scaffolds,
and bioactive molecules to regenerate
damaged tissues. Scaffolds provide a 3D
matrix for cell attachment and growth. Ideal
scaffolds are biocompatible, porous,
mechanically stable, and degrade at a
controlled rate.

17. Stainless Steel as Biomaterial
• Stainless steel (316L) is commonly used in
orthopedic and dental implants due to its
mechanical strength and corrosion resistance.
However, it may release nickel and chromium
ions, leading to allergic or toxic responses.
Surface coatings and passivation improve
performance.