Substantiation of 25 kGy radiation sterilization dose for banked air dried amniotic membrane and evaluation of personnel skill in influencing finished product bioburden

Nagi Marsit,Mohamed Mansur,Ibrahim Saad,Mohamed Abdul Sammad,Samira Dwejen,Arej Shaab,Sedigh Abdalla,Anas Hasan,Enas Khanfas,Salma Salem

doi:10.1007/s10561-014-9433-1

Nagi Marsit, Mohamed Mansur + Show 8 more

Open Access

https://doi.org/10.1007/s10561-014-9433-1

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Abstract

Preparation of amniotic membrane (AM) by air drying method followed by radiation sterilization is simple and valuable approach; sterility and quality of the final AM product are depending on the quality management system at the tissue bank. Validation and substantiation of radiation sterilization dose (RSD) for tissue allografts is an essential step for the development and validation of the standard operating procedures (SOP). Application of SOP is perfectly relying on trained staff. Skills differences among personnel involved in AM preparation could have an effect on microbiological quality of the finished product and subsequently on the RSD required. AM were processed by four different couples of the tissue bank technicians. The AM grafts were randomly selected and subjected to bioburden test to validate and substantiate the 25 kGy RSD. Bioburden test for AM grafts were also useful to evaluate the skill of the tissue bank technicians and thus, to validate the current SOP for air dried AM. Moreover, the effect of placental source on bioburden counts on AM grafts was assessed. Substantiation of the 25 kGy RSD at a sterility assurance level of 10−1, and sample item portion = 1, was carried out using Method VDmax25 of the International Organization for Standardization, document no. 11137-2 (ISO in Sterilization of healthcare products—radiation—part 2: establishing the sterilization dose, Method VDmax—substantiation of 25 kGy or 15 kGy as the sterilization dose, International Standard Organization, 2006). The results showed that there were no significant differences in the bioburdens of the four batches (α = 1 %), this means no significant differences in the skill of the four couples of the tissue bank technicians in terms of their ability to process AM according to the air dried AM SOP. The 25 kGy RSD was validated and substantiated as a valid sterilization dose for the AM prepared with the current established SOP at the Biotechnology Research Center experimental tissue bank. The donor’s type of delivery, normal or caesarean, showed no significant effect on the levels of microbial counts on the tested AMs (α = 1 %).

Highlights

Tissue banking activity and radiation sterilization of tissue allografts has been expanding to many developing countries in the new millennium
The results showed that there were no significant differences in the bioburdens of the four batches (a = 1 %), this means no significant differences in the skill of the four couples of the tissue bank technicians in terms of their ability to process amniotic membrane (AM) according to the air dried AM standard operating procedures (SOP)
The typical operation of a tissue bank to produce sterile tissue allografts necessitates the adoption of any of the tissue banking standards, i.e. American Association of Tissue Banks AATB (AATB 2002), European Association of Tissue Banks (EATB), (EATB 1995), International Atomic Energy Agency (IAEA) standards (IAEA 2003), as well as International Standard Organization ISO documents for radiation sterilization dose (RSD) selection (ISO 11137-1 2006).The confirmation of sterility, safety and efficiency of tissue allografts together with the dose setting and choice of the RSD are the responsibility of the tissue banker (Morales Pedraza et al 2012)

Summary

Introduction

Tissue banking activity and radiation sterilization of tissue allografts has been expanding to many developing countries in the new millennium. During the bank set up phase, AM was prepared by air drying method followed by radiation sterilization. This simple and valuable approach was adopted by the experimental tissue banks especially in developing countries; while sterility and quality of the final AM graft were ensured through the quality system established by the tissue bank. At international level, distinct developments have been taking place in recent years to standardize the processing procedures and facilitate the selection of the terminal RSD for tissue allografts (Morales Pedraza et al 2012).The use of 25 kGy as a terminal sterilization dose for tissue allografts has been practiced for

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