Biomedical polymers are a special class of materials that are designed to work in harmony with the body, and for the basis of a growing number of artificial organs and replacement parts intended for fitting into the human body.
Biomedical Polymer Features
Next to deep space, the human body is the most aggressive environment that materials can be subject to, with changes in PH value, the need for complex movements, and inbuilt aggressive defense mechanisms. Developing new polymers that are able to exist safely within living organisms is a huge business.
Biomedical polymers can actually be divided into two distinct sub-sections; those that remain inert to the complex chemistry and operations of the body, and those that gradually break down in place by intention.
Types of BioMedical Polymers
The first group of materials is the basis of many long-term fitments already in use, such as artificial hearts and replacement trachea. The lack of suitable donor replacements has led to research and development into artificial replacements that can be produced as required, meaning that recipients no longer need to wait months or years to receive a real organ. Materials such as these must be designed to work in combination with the body’s complex systems, otherwise they are liable to fail. In the case of hip replacement components, the medical device is working under stress, which, when combined with chemical attack from the body, can lead to the production of metal ions with metal replacement parts. This can then lead to a condition called metallosis, whereas polymeric materials – typically polyethylene — can lead to small polymer fragments being present and a condition called osteolysis. Both of these can create discomfort and joint pain, joint looseness, and bone deterioration, and can lead to complications if the foreign material is not successfully flushed from the body.
The second group of materials is composed of sutures and other temporary fixings that are used to support the body’s infrastructure as full healing occurs in structure and tissue. The basic reason behind wanting a biodegradable polymer is that there is no requirement for a second surgical event to remove whatever structure has been put in place. Biodegradation offers other advantages too; if a polymer support can be made to degrade and weaken at the same rate as the bone it is supporting strengthens, then the patient does not suffer from a condition known as “stress shielding,” and experiences no difference in the applied stress that the structure feels. While structural materials are generally metallic, there are a number of developments in using initially stiff polymers that dissipate over time, again removing the need for a second operation.
This second class of polymers is also becoming increasingly important in the field of drug delivery and for the measured release of medications according to how fast they decompose under the actions of the body. By encasing a medication in a material that can be made to decompose at a regular and reliable rate means that a drug — such as a painkiller — can be administered to a patient in an orderly way and away from a hospital environment.
Importance of Biomedical Polymers
Biomedical polymers are an increasingly important subfield of polymer chemistry, and significant research is being carried out on how these and other materials interact with living tissue. As our bodies wear out, there is a good case to replacing parts with other materials that can extend life or movement by many years, and possibly even decades. While there is still much more research to do and many biological mechanisms that need to be fully understood to be translated into devices for production, the groundbreaking work in this important field has shown the extent to which these materials can be used to aid health care.
Pivot International is a product design, development, and manufacturing firm with extensive experience in the medtech industry. If you are interested in engineering a new product or updating an existing product, contact us at 1-877-206-5001 or request your free consultation today.