Biomaterials and Nanotechnology for Tissue Engineering
Sunday May 20, 2007, 8:00 am - 6:00 pm, Santa Clara, California
Technology Focus
Historically, synthetic materials have not served as sufficient
implants. For example, the current average lifetime of an orthopedic
implant is only 15 years. Similarly, for the vascular community, small
diameter vascular grafts are only functional 25% of time past 5 years of
use. Clearly, conventional materials have not invoked proper cellular
responses to regenerate tissue that allows for these devices to be
successful for long periods of times. In contrast, due to their ability
to mimic the dimensions of constituent components of natural tissues,
nanophase materials may be an exciting successful alternative. This is
not only due to their ability to simulate dimensions of proteins that
comprise tissues, but also because of their higher reactivity for
interactions of proteins that control cell adhesion and, thus, the
ability to regenerate tissues.
Who Should Attend
This is an introductory course suitable for anyone interested in the
design of the next-generation of better biomaterials and, in particular,
at the intersection of nanotechnology and tissue engineering.
Course Content
This course will focus on the creation of better tissue engineering
through concepts in nanotechnology, i.e. the use of materials with
constituent components less than 100 nm in at least one dimension.
Current Implant Failures
First, we will define current problems with various implants and learn
why current materials fail in the device systems.
Orthopedic: • Current Materials Used • Current Modes of Failure:
Poor bonding to surrounding bone; Generation of wear debris; Stress and
strain imbalances at the tissue implant interface • Current Statistics
on Orthopedic Implant Failure
Dental: • Current Materials Used • Current Modes of Failure: Poor
bonding to surrounding bone; Generation of wear debris; Stress and
strain imbalances at the tissue implant interface • Current Statistics
on Dental Implant Failure
Cartilage: • Current Treatment Methods and Materials Used •
Current Modes of Failure: Poor regeneration of cartilage tissue;
Generation of wear debris; Stress and strain imbalances at the tissue
implant interface • Current Statistics on Cartilage Implant Failure
Vascular: • Current Materials Used • Current Modes of Failure:
Poor bonding to surrounding vascular; Endothelium removal due to shear
stress; Generation of stenosis; Stress and strain imbalances at the
tissue implant interface; Current Statistics on Vascular Implant Failure
Bladder: • Current Materials Used • Current Modes of Failure:
Poor bonding to surrounding tissue; Stress and strain imbalances at the
tissue implant interface • Current Statistics on Bladder Implant Failure
Central and Peripheral Nervous System: • Current Materials Used •
Current Modes of Failure: Poor bonding to surrounding tissue; Build-up
of glial scar tissue; Poor maintenance of electrical properties; Stress
and strain imbalances at the tissue implant interface • Current
Statistics on Central and Peripheral Nervous System Implant Failure
Biological Response of Implanted Materials
Next, we will learn how cells interact with implanted materials to
generate a biological response. We will discuss both desirable and
undesirable reactions of the body with implanted materials.
Protein Interactions with Implanted Materials: • Properties of
Proteins • Adsorption • Conformation/Bioactivity
Cellular Recognition of Proteins Adsorbed on Materials Surfaces:
• Adhesion • Migration • Differentiation
Cellular Extracellular Matrix Deposition Leading to Tissue
Regeneration: • Bone • Dental Tissue • Cartilage • Vascular •
Bladder • Central and Peripheral Nervous System
Foreign-body Response
Inflammatory Response
Wear Debris Response
Advantages of Nanomaterial Use as Implants
How can nanophase materials be used as better implants? What are their
promising properties and what experimental evidence exists? We will sort
through the experimental data and separate promise from “hype”.
Mechanical Properties - Theoretical and Experimental Evidence: •
Ceramics: Increased grain boundary sliding • Metals: Dislocation source
• Polymer Composites
Electrical
Surface: • Biologically-inspired Surface Roughness • Increased
Surface Reactivity
Various Techniques to Synthesize Nanophase Materials
Experimental Evidence of Increased Tissue Regeneration: •
Orthopedic • Dental • Cartilage • Vascular • Bladder • Central and
Peripheral Nervous System
Future Research Directions for Nanophase Materials in Tissue Engineering Applications
Lastly, we will discuss the most promising future directions for the use
of nanophase materials in biological applications. We focus on key
unanswered questions such as the immunological response to
nanoparticles.
Immune System Response: • Basics of Immune System and Particle
Size • Limited Experimental Evidence
Nanophase Materials Coatings: • Various Conventional Coating
Methods • Limited Experimental Evidence
Wear Debris: • Size Relationships for Wear Debris • Limited
Experimental Evidence
Intelligent Nanoparticle Systems: • Basics of Drug Delivery •
Limited Experimental Evidence
Course Summary and Conclusion
Course Instructor
Thomas J. Webster, Ph.D., Associate Professor, Division of
Engineering, Brown University, Providence, RI, USA. Professor Webster’s
research designs, synthesizes, and studies nanophase materials for
various implant applications. Among many awards, Dr. Webster was the
2002 recipient of the Biomedical Engineering Society Rita Schaffer Young
Investigator Award, the 2004 recipient of the Outstand Young
Investigator Award for the Schools of Engineering at Purdue University,
the 2005 Coulter Early Career Award, and the 2005 Finalist for the
American Society for Nanomedicine Young Investigator Award. He also
serves on several grant review panels for the NIH and NSF in the area of
nanobiotechnology.
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