Use of Biodegradable Plastics in Medical Technology

An essential requirement for medical products is that the materials and components used must be sterilizable. Once the sterilization method has been established, the list of materials that are suitable for a medical product is already limited. For certain sterilization processes, plastics cannot be used because of their low heat distortion temperature, low hydrolysis resistance, or low resistance to color change and degradation of the molecular chains. 

Generally, sterility is synonym with the absence of any viable microorganisms including their spores. Currently, the available sterilization methods include heat sterilization (steam and hot-air sterilization), cold sterilization (gas sterilization, sterilization by ionizing radiation), sterilization by aqueous solution (aldehydes, peracetic acid, hypochlorite, hydrogen peroxide), and sterilization by filtration methods. The choice of method is based on recommendations in medicinal literature, legal requirements, and the compatibility of a medical product with the method used. The decision for a particular method has to take the following factors into consideration [954]  

Plastics behavior under common sterilization methods is compiled in Table 5.125. 

Hot air High energy radiation /-rays Electron radiation Source 

How many sterilization cycles a medical product can withstand depends on various factors, such as the material, service temperature, chemical environment, sterilization technique, and/or processing parameters. Therefore, the assembled parts should be checked under specific service conditions [517]. 

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