FUNDAMENTALS OF BIOMATERIALS AND BIOCOMPATIBILITY - Advanced Biomaterials: Fundamentals, Processing, and Applications - page 15

the number of animals and the type of animals for particular in vivo
experiments. Some guidelines need to be followed.
f) When the material is successfully selected for a particular application, it
goes to implant biology section to shape the material into fi nal use. Rapid
prototyping using CAD-CAM technology is the new technique for devel-
oping these materials.
g) The other important aspects of biocompatibility testing are clean room
practice and microbiological evaluation of materials. The laboratory en-
vironment should be free from dust and microbes and totally sterilized.
Distilled water maintenance plays an important role, because in every
step the quality the distilled water, dictates the perfection in experiments.
1.7 BROAD OVERVIEW OF FUNDAMENTALS SECTION
In the Fundamentals section of this topic (section I) , the topics will cover the
structure and properties of calcium phosphates, mechanical properties of bones,
interaction of cells with nanobiomaterials, interface tissue engineering, blood
compatibility, and polymer-ceramic biocomposites. In particular, the fundamental
aspect of structure, processing and properties of the natural bone as well as those
related to various approaches to develop or design new biomaterials is presented
in the chapters under this section. For example, the chapter by Bikramjit Basu
and co-workers broadly discusses the various approaches to optimize the process-
ing conditions or material composition to design biomaterials in metals, ceramics
and polymeric materials for hard tissue replacement. Limited discussion is also
made on biocompatible coatings. It is well known that the inorganic component
of the natural cortical bone is calcium phosphate (CaP) compounds, rich with
hydroxyapatite (HA) phase. In view of this, concerted research efforts were
invested in understanding the structure and properties of HA and subsequently
to modify or refi ning the structure and properties of HA to improve the physical/
biological properties. In this context, the chapter contributed by Racquel Z.
Legeros describes, among many aspects, the fundamental crystal structure of HA
and calcium - defi cient apatite (CDA). The results obtained with various charac-
terization tools in precisely describing the structure of such complex inorganic
compounds are provided. Following the substitution of anion (OH − ) by F − or Cl − ,
(CO3) − 2 and similarly, incorporation of Sr, Ba, Pb to substitute (Ca +2 ) cation are
discussed along with their implication on structure and properties in reference of
stoichiometic HA.
The aspect of synthesis of various types of biologic apatites, including ACP,
DCPDTCP, OCP, TTCP is mentioned briefl y along with the existing/potential bio-
medical applications of CaP-compounds. The chapter by Guy Daculsi describes
the processing strategies to develop micro- and macro-porous biphasic calcium
phosphate (BCP) bioceramics (an optimum balance between the more stable HA
phase and more soluble TCP) for better osteogenicity and osteoinductive pro-
perties. The clinical applications requiring better control of biomaterial resorption