Biocompatibility

Biocompatibility
 

It can be simply defined as the compliance of the medical device when interacting with the patient. Biocompatibility can also be defined as the patient´s non-reaction to the medical product other than expected. The body´s reactions to products vary from person to person. Therefore, it is necessary to ensure a harmony between the patient and the product. Otherwise, undesirable results may occur or it may not reach its intended use. The materials used in this field are referred to as biomaterials.

Biomaterials are materials that enter into or are associated with a living system. Materials that do not react pharmacologically during their relationship with this system are considered compatible.


The most general definition that can be made for biocompatibility; chemical interaction of materials and body fluids and whether or how much the physiological consequences of this interaction harm the body. In some cases, even if the use of biomaterial is harmful to the body, it may be preferable to use this material because the use of the material creates less damage than would occur if it was not used. Biomaterials do not interfere with the normal change of the surrounding tissue and do not cause undesirable reactions in the tissue. Compatibility with the body, that is, biocompatibility, is the most important property of a biomaterial.


Situations where biocompatibility varies are given below.

- Depends on the type of texture
- Depends on the age of the tissue
- Varies according to interface mobility
- Varies according to the circulation of body fluid
- It varies according to the physical and chemical properties of the material
- It varies according to surface morphology and similar features.


The term biocompatibility has been extended and split into two by a number of researchers. These distinctions and definitions are as follows:

1. Structural compatibility
2. Surface compatibility


Structural compatibility is optimum fit. It covers the adaptation of the material to the mechanical behavior of body tissues.

Surface compatibility covers the physical, chemical and biological compatibility between the material and the body.


Some of the hazards that may be experienced in non-biocompatibility situations are given below.

- Damage to the surrounding tissues of the material
- Chemical substances released during the interaction of the material with the surrounding tissue cause damage
- Inflammation
-    Infection
- Clot


The most important chain of conformity assessment processes for biocompatibility is biocompatibility tests. Biocompatibility is the ability of the material to respond appropriately to the body. Biomaterials are natural or artificial materials used to perform the functions of living tissues in the human body or to support these functions and help the cycle. In accordance with this purpose, intensive efforts are made to develop new materials, fields, individuals or institutions in this sector are constantly improving themselves.


Biomaterials are designed to be implanted in a living system and to take over the functions of organs and tissues partially or completely. Some of the properties required for these materials are listed below.

- Being biologically compatible
- Non-toxic
- Not carcinogenic
- Chemically inert
- Chemical stability
- Having sufficient mechanical strength
- Ability to adapt to a busy life
- Appropriate weight and density


Physical, chemical, mechanical and thermal properties of biomaterials should be well known. It is desired that it does not cause allergic reactions and other reactions with the tissue. Biocompatibility of medical devices developed in this context against human tissues

However, it becomes clear with the tests and the results obtained.


Manufacturers all over the world have to prove the compatibility of their products.


Listed below are some / most common tests required or performed for biocompatibility.


- Genotoxicity test
- Blood compatibility test
- Cytotoxicity test
- Implantation test
- Irritation and skin sensitization test
- Systemic toxicity test
- Material and chemical characterization test


Tests for biocompatibility with medical products take a long time. However, they are quite costly. That´s why they need a separate budget. For a medical product or medical device, if there is a date and equivalent product, the tests to be done can be minimized numerically and temporally, and this device can be put on the market immediately. It is acceptable to demonstrate and use biocompatibility in this way. In this evaluation, that is, in the biocompatibility test and publication phase, every step to be made for the medical device can be recorded and all processes can be minimized. In this way, its biocompatibility is accepted. As a result of all these processes, the most common situation is that the product. Attention is also paid to material and characterization tests. It is normal when such planning and evaluation is deemed necessary.