Biomedical Engineering Reference
In-Depth Information
Morphological Approach ................................................................................................. 419
Biological Approach .......................................................................................................... 424
Summary ...................................................................................................................................... 425
References..................................................................................................................................... 426
Introduction
We are now living in an aging population. It is predicted that in the Western world there
will be more people over 65 than under 25 years old by 2015. With the increase in age
come the increases in the number of damaged tissues (e.g., fractured bones) that need to
be treated. The increased inability of the body to repair tissues and organs is a problem
that modern medicine is trying to address. In addition, changes in lifestyle and increased
adoption of high-risk sports among people under 30 coupled with increasing life expec-
tancy mean that design lifetime of implanted devices need to be significantly longer. The
best treatments currently available are to replace damaged tissues and organs with either
transplants or manmade implantable devices, both of which are in limited supply.
In 40 years of research and clinical assessment, many types of biomedical, implant-
able materials (metals, polymers, ceramics, and glasses) have been developed, tested, and
successfully used clinically. As an introduction, these materials will be briefly reviewed.
Attention will be given to bioactive glass (calcium phosphate-based) materials. A review
of the strategies for their manufacture, testing (in vitro and in vivo), and their possible
clinical applications will be presented. In addition, I will introduce the three generational
classifications of these glasses based on their intrinsic surface properties.
Tissues are “living” things and as such they respond and adapt to their local biochemi-
cal and biomechanical environment. Bioactive coating technologies that facilitate altera-
tions in textural properties of the implant/tissue interface to encourage tissue ingrowth
and attachment, limit infection, and host tissue immunological response will be reviewed.
Regenerative medicine is an exciting new strategy and emerging commercial market
where engineered tissues and organs could potentially address the supply of functional
replacement tissues and organs (e.g., bone, cartilage, heart, lung, and kidney).
Finally, a review of nanotechnology-based applications of these bioactive coatings and
surface technologies will be briefly introduced, providing food for thought to existing
developers of these technologies.
Biomaterials
Since the invention of the first generation of biomedical materials there has been an ever-
growing research interest in the development of synthetic biomaterials for use inside
the body [1, 2]. The field couples advances in materials with biological sciences to design
materials with surface properties that deliberately consider the interactions between liv-
ing and nonliving materials. As a result, biomaterials ultimately lead to improvements in
the quality of human health and quality of life [1]. Materials used as biomaterials include
metals, polymers, pyrolitic carbon, polycrystalline materials, glasses, glass-ceramics, and
Search WWH ::
Custom Search