Live Cells and Cytotoxicity Assessment
Problems with the use of conventional cytotoxicity tests to evaluate biological risk with biomaterials are leading to the development of alternative procedures based on cell function. These tests, recently discussed at a conference in China,1 provide an attractive option for the future.
Different Directions for the Biological Evaluation of Biomaterials
The standard tests for the biological evaluation of biomaterials, as promoted by the International Organisation for Standardisation, have evolved over the years to become an important part of the process for ensuring, as far as is possible, the biological safety of medical devices. There is, however...
The Technology of Bacterially Derived Polymers
Twenty years ago, evidence of the lack of biodegradability in a family of supposedly biodegradable polymers caused the curtailment of interest in the potential commercial applications of this family. Now that has all changed following some innovative polymer chemistry and recombinant DNA technology.
The Delicate Balancing Act of Metallic Biomaterials
Ever since metals have been used within the human body, there has been controversy over whether they do harm as well as good. There is now another dimension to this issue provided by experiences with recent metal-on-metal hip replacements.
Doses of Drugs in Devices
Recent experiences with active molecules in spinal fusion devices points to the need to be cautious with dosing regimes and the use of products in off-label situations.
The Role of Nitric Oxide in Biocompatibility
Inflammation is a major factor in the development of the foreign body response to biomaterials and medical devices, including compatibility with blood, and the mechanisms are obviously complex. It has been realised recently that nitric oxide (NO) gas is continuously generated by some cells in the bo...
Fibrous Proteins in Medical Technology
As many sectors of medical technology move away from traditional metals and plastics towards more sophisticated materials derived from supramolecular chemistry, some of the principles developed by nature’s best engineering materials are being borrowed. Discussed here are the structural charact...
Germany Makes New Alliances
Five important areas of change are being advocated to improve the health care market.
Caution and Causation:Lessons From the Delicate Story of Dental Amalgam
There is a long running debate about whether or not dental amalgams represent a serious health hazard because of the mercury they contain. A scientific opinion produced for the European Commission has recommended a solution to the conundrum and provides some lessons for other medical device related ...
A confusing array of terms has arisen with the rapid emergence of the subject of nanotechnology. In this article a recently derived framework for definitions of these terms is discussed.
In Vitro Biocompatibility Testing of Biomaterials and Medical Devices
Biomaterials used for medical devices must be thoroughly tested according to ISO 109931 before their introduction so that any negative effects on the body are known about and prevented. By using in vitro laboratory tests, dangers for patients and unnecessary animal experiments can be avoided. Here, ...
Technologies of Heart Transplantation
It is now 40 years since the world’s first heart transplant was performed at the Groote Schuur Hospital in Cape Town, South Africa. It is interesting to assess just how far heart transplantation has come since then.
Polyetheretherketone For Long-Term Implantable Devices
Extremely few new polymeric materials become adopted by the medical device industry. This is partly because of the quality of existing materials and partly a consequence of the high costs of introducing new ones. The polyaryletherketones, especially polyetheretherketone (PEEK) has broken this trend ...
Cages and Chondrocytes:Techniques to Replace and Regenerate the Troublesome Intervertebral Disc
Techniques for spinal surgery are developing apace, and there are divergent views on the merits of facilitating spinal fusion or attempting to replace or regenerate the degenerative intervertebral disc. The different strategies and preferred materials are described.
The Natural Pace of Healing
Injuries are often seen as unfortunate, inconvenient events, the recovery from which, for economic and social reasons, should be accelerated. However, nature is adept at repairing many injured tissues and we should refrain from unnecessary and illogical attempts to interfere with natural processes.
A European Regulatory Pathway For Tissue Engineering – At Last
After many years of scientific and political struggles, the European Union now appears to be heading for success in the development of a new regulatory pathway for innovative therapeutic products, including those of tissue engineering. This article summarises the main issues of those developments an...
Metastable Biocompatibility: A New Approach
The performance of biomaterials may be better understood by viewing biocompatibility not as a stable state, but as a metastable state. This concept is explored in the context of long-term implantable medical devices and biocompatibility failures.
Carbon Nanotubes in Medical Technology
One of the more important classes of material to emerge from the recent developments in nanotechnology has been the carbon nanotube. A variety of nanoscale carbon tube structures have been prepared and this article discusses their structure, properties and potential medical applications.
The Interface Between Biomaterials Science and Biotechnology
Biotechnology has evolved over the years, moving on from crop protection to drug discovery. Similarly, biomaterials science has moved forward from implantable medical device technology to drug and gene delivery and tissue engineering. It was perhaps inevitable that they should eventually meet.
Late Thrombosis and Drug-Eluting Stents
On 14 September 2006, the United States Food and Drug Administration indicated that it had some concern over “small but significant” increases in the rates of death in patients treated with drug-eluting stents. This article considers the background and consequences of this matter.
The Relevance of Haemolysis Testing
Testing for haemolysis is usually considered an essential part of the strategy for the assessment of biological safety of biomaterials, but the value and relevance of this test is questionable.
Material Surfaces and MRSA
It appears that our hospitals are facing serious threats from antibiotic-resistant bacteria, especially meticillin-resistant Staphylococcus aureus (MRSA). In this article, some of the new materials-related solutions to these threats are discussed.
A Registry for Tissue Engineering Clinical Trials
Because tissue engineering products and processes are now being transferred from laboratory research into clinical applications, questions are being raised about what is the scope of an optimal clinical trial in this sector. A registry for these clinical trials is currently being established.
Quantum Dots in Medical Technology
During the past few years, the rapidly emerging technology of quantum dots has started to have an impact on the techniques of molecular and cellular imaging in medicine. Their advantages are examined here.
New Interests in Magnesium
After decades of developing strategies to minimise the corrosion of metallic biomaterials, there is now increasing interest in using an intentionally corrodible alloy in a number of critical medical device applications. This article examines the rationale for using magnesium alloys in cardiovascular...