Development of a bacteriophage model system to investigate virus inactivation methods used in the treatment of bone allografts
- 77 Downloads
Bone allografts are commonly used in a variety of surgical procedures, to reconstruct lost bone stock and to provide mechanical support during the healing process. Due to concerns regarding the possibility of disease transmission from donor to recipient, and of contamination of grafts during retrieval and processing procedures, it is common practice to sterilise bone allografts prior to issue for clinical use. It is vital that the sterilisation processes applied to allografts are validated to demonstrate that they achieve the required level of bioburden reduction, and by extension that validated models are used for these studies. Two common sterilisation protocols applied to bone allografts are gamma irradiation and ethylene oxide gas sterilisation, and there are currently no validated models available for measuring the anti-viral efficacy of ethylene oxide treatment with regard to bone allografts or readily useable models for assessing the anti-viral efficiency of gamma irradiation treatment. We have developed and validated models for both these sterilisation processes, using the bacteriophage ϕ×174, and utilised the models to measure the antiviral activity of the standard ethylene oxide and gamma irradiation sterilisation processes applied to bone allografts by the National Blood Service. For the irradiation model, we also utilised bacterial spores (Bacillus pumilus). Our results show that ethylene oxide sterilisation (which can only be applied to lyophilised grafts) inactivated >6.1log10 of the model virus, and gamma irradiation (at 25–40 kGy and applied to frozen allografts) inactivated 3.6–4.0log10 of the model virus and >4log10 of the bacterial spores. Gamma irradiation at this dosage is therefore not in itself a sterilisation process with respect to viruses.
KeywordsBone allograft Sterilisation Ethylene oxide Irradiation Bacteriophage
Unable to display preview. Download preview PDF.
We would like to thank the National Blood Service, the Scottish National Blood Transfusion Service and the National Health Service for supporting this study.
- Adams MH (1959) Bacteriophage. Interscience Publishers Inc, New York, USAGoogle Scholar
- Anderson MJ, Keyak JH, Skinner HB (1992) Compressive mechanical properties of human cancellous bone after gamma irradiation. J Bone Joint Surg (Am.) 74(5):747–752Google Scholar
- Christensen EA, Kristensen H (1992). Gaseous sterilisation. In: Russell AD, Hugo WB, Ayliffe GAJ (eds) Principles and practice of disinfection, preservation and sterilisation. Blackwell Science, Oxford UKGoogle Scholar
- Dahlan KZHM (2001) Radiation sciences. In: Nather A (ed) Advances in tissue banking, vol 5, World Scientific, Singapore, pp 309-42Google Scholar
- European Medicines Evaluation Agency. (1996). CPMP/BWP/268/95- Notes for guidance on virus validation studies: the design, contribution and interpretation of studies validating the inactivation and removal of viruses. Available online at: http://www.emea.eu.int/pdfs/human/bwp/026895en.pdf (accessed 11-1-006)Google Scholar
- Guidelines for the Blood Transfusion Services in the United Kingdom (2002) 6th edn. The Stationary Office, London, UKGoogle Scholar
- Schales O, Scales SS (1941) A simple and accurate method for the determination of chloride in biological fluids. J. Biol. Chem. 140:879-84Google Scholar
- Yusof N (1999) Quality System for the radiation sterilisation of tissue allografts. In: Phillips G (ed), Advances in tissue banking, vol 3, World Scientific, Singapore, pp 257-82Google Scholar