Many medical devices are sterilized in their packages to bet

Many medical devices are sterilized in their packages to better ensure device sterility. Using the table, what type of heat (steam or dry) sterilization would be best for the following conditions and why? Metal hip implant packaged in a cardboard box. Artificial lenses (for cataract surgery) made of polymethylmethacrylate packaged in a polyvinyl chloride box. Polymer Glass Transition and Melting Temperatures.

Solution

The metal hip is an implant and already packaged in the cardboard made of cellulose polymer and cardboard is sensitive to moisture & steam therefore; dry heat sterilization is the essential sterilization process for this “metal hip implant” packed in cardboard. The melting temperature of cardboard is low and higher steam sensitive. The hydrolytic stability and thermal resitance with steam for cardboard packing is lesser.

Intraocular lenses (eye lenses) made of polymethylmethacrylate packed in a polyvinyl chloride are associated with higher hydrolytic stability with more thermal resistance. The polyvinyl chloride packaging has melting temperature capacity Tm with 212Celcius degrees. Therefore, it has higher efficiency to withstand steam sterilization or autoclaving

Explanation:

Steam sterilization or moist heat sterilization- It is the process of subjecting biological samples, which are not heat sensitive to the high temperature and to high pressure. This method involves autoclaving to destroy microbial species and dormant spores that are existing within the sample. For example, steam sterilization in which high pressure is applied to kill the microbes at temperature 121centidegrees for about 15 to 30 minutes in an isolated enclosed metal chamber. Bacterial species are going to die due to call wall protein denaturation & precipitation and aggregation followed by death. Dormant bacterial spore cell wall for example, Bacillus species possess their asexual dormant spores and can survive for more than thousand years, at this particular temperature and pressure, this spore cell wall is going to be broken and inactivate DNA material inside the spore. In this type of sterilization, hot steam or moisture is going to play crucial role in destroying the bacterial spores. It require low amount of sample exposure to steam sterilization

In case of dry heat sterilization, biological samples are going to subject to hot air for about 170centidegrees about one hour and in which there is no moisture role. In dry heat sterilization, bacterial species and spores are going to die due to protein coagulation by free radical mechanism. It takes longer time for sterilization process compared to moist heat sterilization and dry heat sterilization is a bit less efficient than moist heat.