Current Situations and Applications of Medical Polymeric Materials
1. Summary:
Medical polymeric material is a kind of synthesized polymeric material which having a special function to restore, replace and regenerate the organisms. This material can be prepared by polymerization which is one of the important components of biomedical material. For polymeric materials have different physical and chemical features by the control of its components and structures to meet all the needs. With the feature of anti biological aging, it has a excellent biological stability and physical performance, mechanical performance as a long-term implant material. Along with advantages of easy processed and shaped, easy obtain of raw materials, easy sterilization, polymeric materials drew people’s high concern. Now it is becoming the mostly widely used medical materials whose demand keeps increasing dramatically in recent years. Now, there are more than 90 kinds of polymeric materials being used world widely, such as orthopedic fiberglass casting tapes. The medical polymeric material used in western countries is increasing at a extent of 10%~20% each year. Take America for example, millions of people suffer from different losses of organisms, organs, disabilities and functional disorders each year, as a result, there are nearly 8 million surgeries with yearly expenditure of 40 billion us dollars, while treatment fees spent on organ failure and organism losses take up half of the total. With the raise of people’s living standard and pursue of life quality in our country, the demand of medial polymeric material will also increase constantly.
2. Classicification and Characristics of Medial Polymeric Material
Nowadays there are two major kinds of medial polymeric materials: Nondegradable material and biological degradable material.
2.1 Non-degradable medial polymeric material includes polyurethane, silastic, polyethylene, etc. It is widely applied in the restore and production of soft, hard organisms and organs of human bodies such as ligament, hamstring, skin, artery, artificial organs, bone and teeth, etc. Its characteristics are as follow: most of them are biological activeness, so they cannot be fixed with organs firmly; what is more, they often lead to reactions such as toxicity and allergy.
2.2 Biological degradable material: the main components of it are polylactic acid, fiberglass, polyvinyl alcohol and modified natural chitosan and protein, etc. In clinical application, it is mainly used in replacing organisms and organs temporarily, or used as drug release system and delivering carriers, absorbing surgical sutures, etc. Its main characteristics: it is easy to degrade; and the degradation products could be flushed out of the body by metabolism; it has no effects on the growth of organisms. Recently, these characteristics have become the development orientation of medial polymeric materials.
3. Special Requirements for Medial Polymeric Material
3.1 Biological Functions: due to different usages of various medial polymeric materials, such as release drug, the releasing feature of drugs is the biological function.
3.2 Biological compatibility: the biological compatibility of medial polymeric materials includes: first: material reactions, mainly including the material is erosive, absorbed, degradable and abrasive, disabled in biological environments. Second, host responses, it includes reactions on parts or the whole body, such as inflammation, cytotoxicity, cruor, allergy, teratogenesis and immunoreactions, etc. For the non-degradable medial polymeric materials, the stability and compatibility are much more important. These problems includes: compatible with cell tissues (blood is included), stability of hydrolyzing, reactions with drugs and medication, calcification, long time function, mutagenic and carcinogenic action, and sterility. For Biological degradable materials, the crucial problems are its absorbability, measurement, concept scope , effects on cell tissues. What is more, these problems also include functions of enzyme and other active substances towards absorbility of medial polymeric materials, absorbility of degradation products, sterilizing impact on degradation function permeating into the polymeric materials and effects of materials towards recovery of wounds. For example, the orthopedic fiberglass casting tapes also have the special sterilizing function towards the wounded parts.
3.3 Process ability: can be shaped, sterilized (ultraviolet rays sterilization, pressure boil, epoxy ethane sterilization, alcohol sterilization, etc.)
For the strict requirements of medial polymeric materials, the research cycle is usually much longer.
