While biomaterials have made enormous progress in recent times, the concept of biomaterials has been around for centuries. In its most basic form it goes back to the Egyptians who used animal sinew to stitch open wounds on humans. It is the fact that the animal sinew used did not prompt a reaction from the human immune system which ensured that the wound was able to seal itself. That was the birth of the biomaterial….
Definition of a biomaterial
The official definition of a biomaterial, from the International Union of Pure and Applied Chemistry, is as follows:
Material exploited in contact with living tissues, organisms, or microorganisms
In layman’s terms a biomaterial describes any substance specifically engineered for one or more medical purposes which interacts with biological systems. In this instance the material is described as biocompatible. Such has been the development in biomaterials of late that they can be used for either therapeutic or diagnostic purposes.
Before we take a look at different areas of biomaterial science it is important to note that a biomaterial produced for medical use is often deemed to be “application-specific”. In effect this means that the biocompatible tag does not mean it is suitable for other medical issues. The human immune system is a very complex creature and while a biomaterial may be biocompatible with a specific medical function, this is unlikely to be across the board.
The use of biomaterials in medicine
Even though biomaterials are commonly used in medicine, biomaterials engineering and science also takes in biology, chemistry, tissue engineering as well as materials science. Some of the more common medical practices which make regular use of biomaterials include:
Stents have been very much headline news for many years now and they are a means of maintaining healthy blood flow in narrowing arteries. This is a perfect example of where biomaterials come into play. Without integrating biomaterials into the stent, the body would reject the stent which could itself cause more medical issues, infections, etc. The use of synthetic materials engineered in such a fashion as not to alarm the body’s immune system allow stents to perform their particular function. Biomaterials are also used with:
- Heart valves
- Skin grafts
- Dental and ear implants
- Artificial joints
- As well as methods of stimulation for damaged nerves
Promoting the healing of human tissue
The ability to actually promote and encourage the body’s natural healing process is a mind blowing concept. As we touched on above, the use of animal sinew as sutures was recorded centuries ago and is a basic form of biomaterial. Biomaterials can also be used in other processes such as:
- Wound clips
- Wound staples
- Dissolvable dressings
The area of dissolvable dressings is a very interesting one especially in relation to burn injuries. Not only is it possible to create biomaterials which encourage healing and tissue repair but these dressings dissolve naturally. This may seem like a relatively innocuous use of biomaterials but dressings used for burn injuries can very often “grow into the wounds” causing more damage when they are removed. The ability to use biomaterials which dissolve naturally over a predetermined time span is invaluable in terms of patient care and medical costs.
Biomaterials and tissue engineering
It is now possible to regenerate human tissue in the science lab using biomaterial supports, cells and active molecules. In traditional transplants, for example human hearts, the patient may need to take strong drugs for the rest of their life to ensure their immune system does not reject the transplant. If the immune system is triggered into thinking it is under attack by foreign bodies, in this instance a heart, the consequences can be literally fatal. The ability to use biomaterials to encourage the regeneration of tissues and acceptance of organs such as a human bladder grown in the lab is priceless.
There have been enormous strides in this area in recent times with one example that of a bone regenerating hydrogel which encourages bone repair. After the body is triggered into a process of natural regeneration the biomaterial substance degrades and is effectively flushed away. It is not difficult to see the enormous potential for the use of biomaterials in this particular area.
Molecular level therapy
Nanoscience has been around for some time, incorporating everything from clothing material to medicine. The integration of nanoparticles with biomaterials has created a significant breakthrough in the monitoring and treatment of conditions such as cancer at molecular level. There is no way that scientists would be able to probe into conditions such as cancer at molecular level without the cover of biomaterials. These materials ensure that the body does not switch into attack mode and create an impenetrable wall.
The ability to probe medical conditions such as cancer at molecular level is in itself a major breakthrough which will assist in the Holy Grail of cancer treatment, personalised treatment. This ensures that the correct type of medicine is targeted at the appropriate type of cancer thereby significantly increasing success rates. This method also ensures minimum wastage of medicine and thereby reduces long-term costs. Biosensors coated with various biomaterials can be injected into the body to monitor issues such as brain activity and blood glucose levels. It is not only their ability to monitor the level of these substances which is important but also the ability to transmit this data back to scientists.
Again, this is where personal medical treatment will eventually come into play because doctors and scientists will be able to monitor the reaction of cancer cells at molecular level to certain types and certain degrees of medication.
Biomaterial coated drug delivery systems
As we touched on above, the use of medical stents has increased over recent years although without the use of biomaterials (helping to prevent the body’s immune system from rejecting the stents) the results would be nowhere near as impressive. We’ve also seen the creation of “chemotherapy wafers” which are literally implanted into cancer sufferers allowing for targeted chemotherapy without the general side-effects.
In some cases, medical stents being a prime example, these can be made purely from biomaterials which are biocompatible for specific medical purposes. The materials can be created in such a way as to naturally degrade over time to be eventually flushed out of the body. Over the years we have seen issues when stents have been removed and damaged stents causing blood clots with potentially fatal consequences.
Biomaterials impact factor
The “impact factor” of an academic journal is a means by which the relative importance of a journal can be measured against peers within the same field. Originally devised by Eugene Garfield, founder of the Institute for Scientific Information, the figure reflects the number of times an average paper in a journal is cited over a period of time. The higher the “impact factor” the more important the journal is deemed to be.
In relation to biomaterials there has been a gradual increase in the impact factor:
- 6.646 in 2008
- 7.365 in 2009
- 7.882 in 2010
- 7.404 in 2011
- 7.604 in 2012
- 8.312 in 2013
- 8.557 in 2014
- 8.387 in 2015
- 8.402 in 2016
The cumulative impact factor for 2017/18 is calculated at 8.806 and this reflects the growing importance of biomaterials across scientific journals. As research and development budgets targeting biomaterials continue to rise so we can expect a gradual increase in the “impact factor” going forward.
The World Bio Congress, Biomaterials Conference 2018, was held between the 16th and 18th of August in London. The theme for this particular conference was “Innovative Biomaterial Technologies for Life and Society” with a keynote speech from Dr Devika Chithrani on the subject of “Smart Nano Materials for Cancer Therapy”. The conference continues to grow in popularity with eminent featured speakers giving their views on progress to date and hopes for the future. The pace of discovery in the field of biomaterials is certainly increasing and the Biomaterials Conference 2019 is eagerly awaited. A society for biomaterials is quite literally emerging before our eyes.
As reflected by the growing biomaterials impact factor there is significant competition in the area of bio materials journals. This is a very fluid area of research with the Scimago Journal & Country Rank system perfectly reflecting this. In 2017 the top 10 ranked biomaterials journals were as follows:
- Nature Reviews Materials (published by Nature Publishing Group)
- Advanced Functional Materials (published by John Wiley & Sons Ltd.)
- Small (published by Wiley – V C H Verlag GmbbH & Co.)
- Biomaterials (published by Elsevier Ltd.)
- Advanced Healthcare Materials (published by John Wiley and Sons Ltd)
- Acta Biomaterialia (published by Elsevier BV)
- Biomacromolecules (published by American Chemical Society)
- Journal of the Royal Society Interface (published by The Royal Society)
- Biofabrication (published by Institute of Physics Publishing)
- Tissue Engineering – Part B: Reviews (published by Mary Ann Liebert Inc.)
Scientific journals are the food which feeds the continuous development of biomaterials with particular focus on the world of medicine. The ability to compare and contrast, share and discuss, ideas and thoughts about the future direction of the biomaterials industry is priceless.
The future of biomaterials
Biomaterials are created using an array of natural or synthesised substances such as metallic components, ceramics, polymers and composite materials. It is from these relatively simple building blocks that new technologies are being created which will have a material impact upon the world of medicine for many years to come.
While there were concerns about the quality and longevity of 3D printed products, these concerns have faded into the background in recent years. A number of biomaterial companies are now actively looking to make 3D printed biomaterials or use 3D printing as a means by which to create scaffolding to seed living cells. The use of hybrid polymers is integral in this process allowing the 3D printed products to be used to repair tissue damage and bone defects. There are a number of benefits when using 3D printing technology such as the fact products are identical and costs are kept to a minimum.
Body charged batteries
While this is not necessarily a new concept, the idea of introducing long-term drug release/drug monitoring products into the body is now an integral part of the biomaterials sector. The ability to mask these “devices” with biomaterials ensures their acceptance by the body’s immune system. However, it is the ability to create biomaterials which will convert the body’s mechanical processes into energy, to recharge batteries, which is currently headline news.
Future growth of global biomaterials market
The global biomaterials market is expected to show a compound annual growth rate of 11.5% between 2018 and 2024. Many experts have pinpointed the use of biomaterials in hip/knee replacement procedures as one which has significant potential for growth. It is common knowledge that the worldwide population is living longer which is putting more pressure on institutions such as the NHS. The ability to streamline the replacement of various joints and ensure, by using biomaterials, that these are readily accepted by the body’s immune system will in itself attract a significant increase in future investment. There is also particular focus on neurology disorders as well as new trends in plastic surgery and biomaterials induced wound healing processes. However, there is every chance that in 12 months, new developments will completely overshadow what we see as ground breaking today.
Biomaterials science/biomaterials engineering is certainly growing in popularity and attracting significant investment from some of the world’s major pharmaceutical groups. The ability to effectively disguise certain materials and components from the body’s immune system, via the use of biomaterials, is priceless. This technology will play an integral part in so many different areas of medicine in the years to come, from drug delivery systems to dissolving bandages, from materials which stimulate bone generation to the regrowth of nerve cells, and much more.
The body’s immune system has over the years proven to be extremely challenging for the medical profession and scientists alike. Cracking the code to acceptance, switching off the immune system’s death wish in the form of diabetes as well as monitoring and transmitting invaluable data from within a patient’s body are all quite literally within reach.