The following is the medical device absorbable materials related information:
The human body has an extremely complex physiological environment, there are a variety of factors affecting the performance of the material. Coupled with the different types of materials, their degradation behavior in vivo, including the degradation mechanism in vivo is not the same. Therefore, the elaboration of the concept of degradation is inconsistent when the degradation problem is discussed from different perspectives. There are two main ways of expression.
1. Definition of biodegradation in biomaterials science
In 1987
In the book "Definition of Biomaterials", "biodegradation" was defined as the process of gradual destruction of materials caused by specific biological activities. The process of degradation of materials in the body. In fact, the degradation of materials in vivo is often the result of a combination of factors*** or interactions
. With the exception of articles devoted to the study of degradation mechanisms, degradable and resorbable materials are usually broadly defined as materials that can be progressively destroyed and eventually disappear completely in living organisms. In biomaterials-related books
and literature, there are many terms for degradable materials, usually "Degradable", "Biodegradable", "Bioabsorbable
(Bioabsorbable, Bioresorbable) materials", "Bioerodible (Bioerodible) materials" and so on, they all have different meanings.
2. Definition of biodegradation in international standard ISO10993
International
International standard ISO10993 is a standard for biological evaluation of medical devices. The General Principles for the characterization and quantification of potential degradation products (ISO10993-9, referred to as the General Principles) are based on
ISO/TR10993-9 (Technical reports:
Degradation tests related to biological tests). Together with ISO 10993-13, ISO 10993-14, and ISO 10993-15
(Characterization and quantification of degradation products of polymers, ceramics, metals, and alloys), it constitutes a relatively complete test standard for identifying, analyzing, and measuring the degradation of materials in living organisms. The general principles provide general guidelines for the systematic
evaluation of the degradation properties of specific materials and the design of research programs. The standard defines degradation, biodegradation, bioabsorbable medical materials, and degradation products:
(1) Degradation: the cleavage of a material.
(2)Biodegradation: Degradation caused by the biological environment. Biodegradation can be simulated by in vitro tests.
(3)Bioabsorbable medical materials: Materials that can be degraded and absorbed in the biological environment of the body.
(4) Degradation products: All chemical components produced by the cleavage of raw materials.
By
The above definition can be seen in the human body such a complex environment, the implanted materials in the body for a long time in the physical, chemical, biological, electrical, mechanical and other factors under the complex influence, the material is not only subject to a variety of organs and tissues constantly
movement of the dynamic role, but also in the metabolism, absorption, enzyme-catalyzed reaction. At the same time, different parts of the implant are often in relative motion. Under such multi-factors, long-term, comprehensive effect, for some materials is very
hard to maintain the original chemical, physical and mechanical properties, resulting in degradation. In biomaterials science, degradation of materials refers to the complete degradation of materials in the body, and the degradation products can be absorbed and metabolized by the body. The degradation referred to here
reflects a general characteristic of the material or device in the human body, and is not specific to a particular type of material. The concept of degradation involved here encompasses both structural cracking or corrosion of materials due to mechanical wear and tear between the various components of a device, as well as due to interactions between living organisms and the materials
. The latter is also known as biodegradation. It can be seen that the degradation products may be either the particulate body material debris and its cleavage products resulting from mechanical wear and tear, or
the free ions or organic or inorganic compounds with a different chemical structure from that of the body material released from the surface of the material as a result of biodegradation.
Taken together, degradation, biodegradation, and bioabsorbability are concepts that speak to different scopes. A material may or may not have all three properties at the same time. The term "degradable materials" in this chapter refers to all materials that can be completely degraded in living organisms and completely absorbed and metabolized.