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Book Review The Chemistry of Medical and Dental Materials By John W. Nicholson

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Books
and a good picture of the different
modes of operation of these complex
and powerful systems is given. This
introduction gives the reader a summary
of all practical aspects that have to be
taken into consideration for LC-NMR
operation.
The main part of the book deals with
applications of LC-NMR and LC-NMRMS. A chapter by J. C. Lindon and coauthors is devoted to biomedical and
pharmaceutical applications. In particular they describe some interesting
results on the characterization of a
mixture of 27 tripeptides arising from
combinatorial chemistry. Strategies used
for identifying impurities or for studying
the reactivity of drug glucuronides are
also mentioned. Applications of superheated water LC-NMR-MS of pharmaceuticals described in this chapter are
significant, since they provide an interesting way to avoid problems of solvent
signal suppression.
In another section various aspects of
LC-NMR in drug metabolism studies
are described by J. P. Shockcor. The use
of 19F LC-NMR-MS for the localization
of the metabolites of a fluorinated
parent drug and subsequent stop-flow
2D analysis for identification demonstrate the power of such an approach in
this field.
M. Sandvoss summarizes the applications to natural products and demonstrates the advantages of the on-line
approach for the screening of biologically active fractions and for de-replication purposes. The importance of the
complementarity of LC-NMR and LCMS for on-line structure determination
is emphasized with examples. A very
nice study combining sample enrichment by matrix solid phase dispersion
(MSPD) and a subsequent on-flow LCNMR-MS study of various asterosaponins is given as an example, and practical
solutions for H-D back-exchange in MS
detection are discussed. In the same
section, applications of LC-NMR in
combination with modern extraction
techniques for the analysis of geometric
carotenoid isomers are interestingly
described by T. Laser and K. Albert.
A. Preiss and M. Godejohann give a
comprehensive review of the applications of LC-NMR in environmental
problems, and demonstrate the interest
of the approach for nontarget analysis of
2818
organic compounds in the samples. On
the basis of the LC-NMR and LC-MS
investigations, target analysis of identified pollutants can be developed efficiently in a second step using more
sensitive methods.
The last part of the book deals with
related NMR-coupled techniques such
as those with gel permeation chromatography (GPC-NMR), supercritical
fluid chromatography (SFC-NMR),
and the newly emerging capillary
HPLC and electrodriven separation
techniques such as capillary electrophoresis (CE-NMR). The on-line GPCNMR coupling method opens new
opportunities for the characterization
of polymers in general, and several
examples selected by H. Handle and
K. Albert are discussed. SFC is very
often considered as a niche separation
technique. However, the coupled SFCNMR method has the inherent advantage that no solvent signal suppression is
needed, and the whole proton chemical
shift range can be used without distortion by solvent signals or impurities.
These aspects are discussed in various
applications related to nonpolar analytes.
In a section devoted to NMR spectroscopy in the microdomains, all
aspects of small volume RF probes are
well summarized and strategies for
increasing signal-to-noise ratio are
nicely explained by M. Lacey and coauthors. Although the development of
nanoliter volume probes is still in the
research phase, the enhancement in
sensitivity already achieved is exciting,
and this type of technology will make
mass-limited analytes accessible to
NMR analysis. An extension of these
developments is the coupling of capillary electrophoresis to NMR spectroscopy. In an impressive application of this
technique to a real-life problem, the
analysis of a black beetle extract, it was
shown that good quality 1H NMR spectra of the two main quinonic constituents could be obtained with only a 5 ml
injection of the extract.
In summary, this fascinating book is
an invaluable reference source for
researchers currently working with LCNMR, but it also represents a valuable
source of information for scientists dealing with structure elucidation problems
in relation to separation sciences. Con-
2 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
sidering the very recent developments in
miniaturization, and the prototype LCNMR probes with remarkably high
sensitivity values that became available
in 2002, one can safely bet that new
impressive applications of LC-NMR in
real world applications will find a good
place in a second edition of this book.
Jean-Luc Wolfender
Institut de Pharmacognosie et
Phytochimie
University of Lausanne (Switzerland)
The Chemistry of Medical and
Dental Materials
By John W. Nicholson. (Series: Materials Monographs.)
Royal Society of
Chemistry, Cambridge 2002. xii þ
242 pp., hardcover
£ 69.50.—ISBN
0-85404-572-4
Materials research and medicine: these
two disciplines meet in the area of
biomaterials, which has become very
important from both the clinical and the
economic standpoints. The only aspects
of this that normally healthy people are
likely to come into contact with before
their old age are contact lenses and
materials to repair or replace teeth, and
consequently many of us are not aware
of the extent to which modern clinical
medicine relies on man-made materials.
Some of the more familiar examples are
artificial hip joints and tooth implants,
but how many people know that every
day thousands of pins, nails, plates,
screws, artificial heart valves, and bone
prostheses are implanted? Here chemistry plays a vital role in identifying
suitable materials and assessing how
well they interact with human tissues.
This book by John W. Nicholson discusses these many different types of
materials from a chemical standpoint.
Therefore, the contents are organized
Angew. Chem. Int. Ed. 2003, 42, 2817 – 2819
Angewandte
Chemie
according to types of materials rather
than clinical applications, an arrangement that is probably suitable for a
reader with a chemical background.
Accordingly, the preliminary survey
in Chapter 1 (“Synthetic Materials in
Medicine”) is followed by three chapters dealing in turn with the main classes
of medical materials: polymers, ceramics, and metals. Each chapter deals first
with general aspects, then discusses
some examples in detail. In these chapters the author emphasizes certain
topics. Thus, the chapter on polymers
contains detailed sections on polyethylene (used for joint capsules) and on
polymethylmethacrylate-based
bone
cements, both of which are applications
in endoprostheses, whereas biodegradable polymers, polyurethanes, hydrogels, and silicones are treated more
briefly. The author is himself a polymer
chemist, as the reader would certainly
guess from this chapter.
The chapter on ceramics discusses
calcium phosphates in considerable
detail, with special attention to calcium
phosphate cements for bone substitutes
and hydroxyapatite coatings on endoprostheses. However, only a little information is given about the widely used
hydroxyapatite-based bone substitute
materials, and the equally important btricalciumphosphate-based
materials
are not mentioned at all. But then
bioglasses and glass ceramics are discussed in detail, which is perhaps due to
the fact that Nicholson and Hench, the
inventor of bioglasses, have both
worked in London for a long time. The
chapter ends with short sections on
aluminum oxide and zirconium dioxide
(both of which are used in hip-joint
replacements) and on pyrolytic carbon.
There are a few factual errors in this
Angew. Chem. Int. Ed. 2003, 42, 2817 – 2819
chapter, which I will not list; they can be
excused by the fact that this is not the
author?s main field.
The chapter on metals discusses the
most important materials, with emphasis
on those that are used in endoprosthetics, in particular cobalt-chromium alloys,
stainless steels, and titanium and its
alloys. The noble metals and amalgams
used in dental replacement work are
also described. I was surprised to find no
description of the shape memory alloy
Nitinol, which is widely used in coronary
surgery (for stents to open blocked
arteries) and in orthodontics (teeth
brace wires).
After that chapter devoted to particular materials comes one that is
application-oriented: “Dental Materials”. This describes various adhesives,
cements, and filling materials, mostly
polymer-based. Calcined ceramics (used
for crowns) are not included. The next
chapter, on biological interactions, contains an expert and very detailed discussion of the fundamentals of biocompatibility and bioactivity, including such
aspects as sensitization, inflammation,
and carcinogenicity. The final chapter,
“Tissue Engineering”, seems to sit
rather awkwardly in the book as an
afterthought, describing in five pages
recent developments in artificial growth
of tissues (skin, cartilage, bone). This
relates only indirectly to the subject of
materials, but nevertheless the author
and publishers evidently thought it
important to include this highly topical
area of work.
The book contains about a thousand
literature references. Consequently,
because of the frequency of citations, it
reads more like a long review article
than a textbook. That is certainly a
valuable aid to finding one?s way into
www.angewandte.org
the specialist literature, but it leads to a
style resembling a list of facts (each one
with a reference), and that sometimes
interrupts the ease and rhythm of reading.
The text is illustrated by some blackand-white photographs, but I feel it
would have benefited from a few more
of these. Some of the illustrations are of
rather poor quality (e.g., those on pp. 74
and 77). A comprehensive index is
provided. At the beginning of Chapter
1 there is a glossary explaining just nine
(!) terms, as follows: arthroplasty,
embolism, fracture mechanics, toughness, Hank?s balanced salt solution,
Ringer?s solution, stem cells, tensile
strength, and abrasion. I feel that this
small selection is insufficient to enable
readers with different levels of previous
knowledge to cope with specialist terminology, and the choice of these nine is
not very helpful. The book requires
readers to have reached at least intermediate degree level, and even then
they will occasionally need to look up
specialist terms.
To summarize, the book is wellworth reading and provides a good
description of the present state of the
art in the field of biomaterials. The
author concentrates on some selected
aspects, but nevertheless all the important points are covered. It can be
recommended for chemists and materials scientists who wish to learn about
this field, and it serves as an introduction and also to some extent as a
reference source.
Matthias Epple
Anorganische Chemie
Ruhr-Universit=t Bochum (Germany)
2 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2819
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