Methods of sterilization of medical polymer composites based on polyhydroxybutyrate with elastomeric additive

Introduction. Polyhydroxybutyrate is a biodegradable and completely biocompatible component, and in combination with various modifying additives can be suitable for the manufacture of medical products used in surgical practice as bone implants or their parts. There implants have a number of advantages over traditional metal products, but for their integration into the body they require thorough sterilization cleaning, which in the case of polymer compositions has a number of limitations associated with the possible destruction of the material structure during various cleaning stages.

Purpose of the study. Find optimal methods for sterilization and disinfection of materials based on polyhydroxybutyrate (PHB) and an elastomeric additive – butadiene-nitrile rubber (NBR-28).

Material and methods. Two-component PHB-NBR compositions with PHB content from 30 to 90% were studied. Four methods of sterilization and disinfection were used: autoclaving, air sterilization, disinfection with chlorine solution and ethanol solution. Determined mechanical characteristics are strength and elongation of the material at break. Sterility control – by the method of washings with subsequent observation of the growth of bacteria and fungi in Sabouraud's medium and thioglycollate medium.

Results. Sterilized and disinfected samples showed no microbial growth in both culture media. No change in mechanical characteristics was detected for samples subjected to solution cleaning methods. High temperature cleaning reduced the mechanical properties of samples by 20–80% depending on the sterilization mode.

Conclusions. The data obtained show that for sterilization and disinfection of PCM based on the biodegradable polymer PHB, solution methods are suitable without restrictions and the autoclave sterilization method is suitable with minor restrictions, while air sterilization leads to the destruction of PCM.