Biomedical Engineering Reference
In-Depth Information
1
Biomaterials and Sol-Gel Process:
A Methodology for the Preparation of
Functional Materials
Eduardo J. Nassar et al
*
Universidade de Franca, Franca, Sao Paulo,
Brazil
1. Introduction
There are many kinds of materials with different applications. In this context, biomaterials
stand out because of their ability to remain in contact with tissues of the human body.
Biomaterials comprise an exciting field that has been significantly and steadily developed
over the last fifty years and encompasses aspects of medicine, biology, chemistry, and
materials science. Biomaterials have been used for several applications, such as joint
replacements, bone plates, bone cement, artificial ligaments and tendons, dental implants
for tooth fixation, blood vessel prostheses, heart valves, artificial tissue, contact lenses, and
breast implants [1]. In the future, biomaterials are expected to enhance the regeneration of
natural tissues, thereby promoting the restoration of structural, functional, metabolic and
biochemical behaviour as well as biomechanical performance [2]. The design of novel,
inexpensive, biocompatible materials is crucial to the improvement of the living conditions
and welfare of the population in view of the increasing number of people who need
implants [3]. In this sense, it is necessary that the processes employed for biomaterials
production are affordable, fast, and simple to carry out. Several methodologies have been
utilized for the preparation of new bioactive, biocompatible materials with
osteoconductivity, and osteoinductivity [4 - 13]. New biomaterials have been introduced
since 1971. One example is Bioglass 45S5, which is able to bind to the bone through
formation of a hydroxyapatite surface layer [14]. The sol-gel processes are now used to
produce bioactive coatings, powders, and substrates that offer molecular control over the
incorporation and biological behavior of proteins and cells and can be applied as implants
and sensors [15 - 17]. In the literature there are several works on the use of the sol-gel
process for production of biomaterials such as nanobioactive glass [18], porous bioactive
glass 19, and bioactive glass [20 - 22], among others.
Hybrid inorganic-organic nanocomposites first appeared about 20 years ago. The sol-gel
process was the technique whose conditions proved suitable for preparation of these
materials and which provided nanoscale combinations of inorganic and organic composites
