INITIATION OF BONE AND AMNION BANKING IN TURKEY
A.Yilmaz ERKOL, Hilal HAZNEDAROGLU, Turkan OZKARA, Halim TASKIN
Qekmece Nuclear Research and Training Center, Department o f Chemistry P.O. Box 1, Ataturk Airport, 34831 Istanhul/TURKEY
ABSTRACT
There is a growing demand in Turkey for human tissue to use in surgery and wound healing. However, our country does not have facilities for local production of tissue grafts and generally depends on imported products. Under a multi-year project initiated in 1997, the International Atomic Energy Agency (IAEA) has provided main equipment for tissue processing and experts on tissue banking as well as training on tissue processing methods.
In this presentation, information on various stages of the project implementation is given. Details of lay out for the process laboratories and list of equipment supplied by the Agency and purchased locally are also given. Donor selection and testing, processing procedures for bone and amnion, setting up product design, implementation of quality system and radiation sterilisation are described briefly. Quality procedures included preparation of quality manual, Standard Operating Procedures (SOP), record forms, document control, non-conformance and corrective actions, training records, equipment maintenance and calibration are all in line with Good Manufacturing Practice (GMP) standards. Clinical applications of tissue grafts and medico-legal position of organ and tissue donation in Turkey are also discussed briefly.
INTRODUCTION
Biological tissue grafting was begun as early as 5th century. However, modem practice of tissue grafting was invented 19th century (1). The first established tissue bank is the one set up at Czechoslovakia and began its activity in 1952. Since that time, biological tissue grafts are used widely in many countries.
As it is known, cancer, degenerative diseases and trauma cause tissue defects. However, tissue defects may destroy functional wholesomeness of the body. Therefore, tissue grafts are very important biological materials for enhancing the quality of human life.
There are 4 types of grafts. Autograft is tissue taken from one part of the body and transferred to another site in the same individual. Allograft is tissue obtained from one individual and transplanted
human. Syngraft is tissue transplanted from one individual to another of same species who is genetically identical, such as a monozygotic twin. The adjectives referring to these grafts are autogeneic, allogeneic, xenogeneic and syngeneic (2).
The applications of nuclear development have led the IAEA into health related areas, notably nuclear medicine and radiotherapy. One of the major industrial uses of ionising radiation, in the medical field, has been for the sterilisation of medical products. It was this area of successful expertise, which led the IAEA in the early 1970’s towards the sterilisation of biological tissues and pharmaceuticals.
At the beginning, ethylene oxide, heat and chemical agents were used to sterilise tissue grafts and disposable medical products; but their toxic effects and limited tolerance for specialised systems led radiation sterilisation to be superior over them. The advantages of radiation sterilisation may be summarised as (3):
■ No significant rise in temperature, physical and chemical changes are induced which influence the required function of the tissues,
■ The high penetration enables the bulk of the hard or soft tissues to be sterilised in their final packed form,
■ The effect is instantaneous and simultaneous for the whole target.
■ The process control is precise and can be applied accurately to achieve sterility. Irradiation time is the only variable.
These advantages make radiation sterilisation to be the most preferable method for the sterilisation of biological tissues.
There is a growing demand in Turkey for human tissue grafts to use in surgery and wound healing. Radiation sterilised bone allografts have started to be used in orthopeadical surgery, oral and maxillofacial and dental surgery in our hospitals.
Since Turkish Government is particularly keen to introduce new and modern technologies to improve general health conditions of the population, application of radiation technology to sterilise disposable medical products has already been introduced to Turkey with the technical assistance of the Agency. However, radiation sterilised tissue grafts are still being supplied by the other countries. Turkey spends hundreds of thousands of US dollar for this purpose. Thereupon, under a multi-year project initiated in 1997, the IAEA has provided main equipment of tissue processing and experts to establish the first tissue bank in Turkey.
The mission of the tissue bank is:
• To develop a national capability for radiation sterilisation of tissue grafts for safe and effective clinical application,
• To provide high quality grafts to tissue transplantation services, patients, physicians, and hospitals,
• To conduct research and development directed at improving the quality of tissue transplantation,
• To provide education and consultation in tissue transplantation medicine. The various stages of setting up of the tissue bank are given below:
BUILDING AND FACILITIES
As planned a new purpose-built Tissue Bank building has been completed. It has total floor area of 120 m2 comprising a bone processing laboratory, an amnion processing laboratory, a freeze drying and packaging room, a room for auxiliary equipment, a freezer room and an office for the personnel. All the processing laboratories are disinfected areas (class K ) which are in line with the British Standard. Clean air is supplied to the processing areas through HEPA filters.
EQUIPMENT
All the equipment for tissue processing requested from the Agency have arrived and been installed in the tissue bank. The total worth of equipment is ~US $ 70.000 and they are ultra-low temperature freezer (-80°C ), freeze dryer, band saw, biological safety cabinet, saggital saw, bone mill, sealing machine, shaking water bath, ultrasonic bath, PC and printer.
In addition to the above equipment supplied by the Agency, our authority (TAEA) has also purchased air conditioning system, shaking water bath, autoclave, overhead stirrers, deep freezers (-30°C ), ultra-centrifuge, saggital saw blades, hot plates, surgical gowns and slippers, and consumable items such as gloves, masks, wipes, surgical disinfectants, etc. The tissue bank has now all the basic equipment necessary to process tissue grafts.
STAFFING AND TRAINING
The sufficient staffing level has been put in place and their training programme has been completed. The duties of the project leader are to set up and develop the tissue bank. 3 Full-time staff transferred from the hospitals in Istanbul. In addition to them a nurse from the Center’s clinic,
medical team, led by the Center’s physician who acts as a Medical Director to the bank. The all above mentioned staff have medical knowledge and familiar to aseptic techniques. Apart from them, two research chemists from the Chemistry Department are also providing support to the tissue bank on a part-time basis.
6 personnel have been trained on various aspects of tissue banking in the tissue banks of U.K., Poland, Malaysia and Czech Republic.
SUPPLY OF TISSUES
At present, tissues are obtained from living donors (femoral heads collected during primary hip replacement surgeries and amniotic membranes from placentas after vaginal or caesarean delivery). The serological tests for HIV/AIDS, Hepatitis C (HCV), Hepatitis B (HbsAg) and Syphilis (RPR) are completed for the potential donors. After completion of the serological tests, the tissues are brought from the hospitals to the tissue bank. They are stored in an ultra low temperature freezer at -80 0C until processing. The records are designed and kept for the donors and the tissues received. PROCESSING
For the bone processing, the femoral head is removed from the deep freezer for pasteurisation at 58 0C. The aim of pasteurisation is to eliminate any risk of transmission of HIV to the recipient and tissue bank staff. After pasteurisation, the head is dissected to remove cartilage and soft tissues. Dissected femoral head is shaken with cleaning solution and sterile water in cocktail shaker for removing blood and fat inside. Shaking with the solution and water is repeated for several times together with centrifugation to remove blood and fat from the femoral head by gravimetrical force. The femoral head is then cut into certain shapes requested by clinics of the hospitals. The shaped bone grafts are then freeze dried in a programmable freeze drier for 24 hours. The last step before the radiation sterilisation is to pack the bone grafts. The three-fold packaging and labelling are carried out in a biological safety cabinet under laminar airflow.
For amniotic membranes, the process is different than bone process. After completing serological tests of potential donors, the placentas are brought to the tissue bank. Corio-amniotic membrane is separated from placenta and put into physiological saline solution for shaking in water bath at 370C. The aim of this action is to remove blood vessels and non-relevant tissues. The following step is to shake the membranes in %10 sodium hypochloride solution to eliminate any risk of HIV. The membranes are then rinsed with sterile water for several times and lay down on gauze with cutting into desired sizes. After freeze drying the membranes in freeze drier for 48 hours, packaging and labelling are carried out in a biological safety cabinet.
RADIATION STERILIZATION
Sterilisation by gamma radiation is carried out at the TAEA’s irradiation plant. The sterilising dose of 25 kGy has been chosen and the sterilised grafts will be checked routinely for post-irradiation sterility assurance. Radiation sterilised bone grafts can be stored for 2 years at room temperature. QUALITY SYSTEM
Considerable amount of work has been done to introduce and implement quality system within the tissue bank. Quality procedures include writing quality manual, standard operating procedures, record forms, document control, non-conformance and corrective actions, training records, equipment maintenance and calibration, etc., are all line with GMP standards.
CLINICAL APPLICATIONS
During this past decade, bone allografts have achieved widespread clinical application by orthopaedic surgeons, neurosurgeons and periodontists. Bone allografts are frequently used to provide acetabular and proximal femoral support for the revision of failed prosthetic hip joints, to fuse the cervical or scoliosis, to pack benign bone cyst, to restore alveolar bone in periodontal pockets, to reconstruct maxillofacial deficits, to replace bone tumours and to unite unhealed fractures (2).
According to the bony defect in mandible or maxilla, it is possible to choose powder, chips, or blocks of frozen of freeze-dried cancellous or demineralised bone.
Freeze-dried and radiation sterilised amniotic membranes are widely used for (4): • Superficial burns (Second degree burns)
• Chronicle leg ulcers • Post-traumatic wounds • Vaginoplasty
MEDICO-LEGAL POSITION OF ORGAN AND TISSUE DONATION IN TURKEY
The issue of organ/tissue donation is a sensitive matter. However, efforts have been made by the Turkish Government and hospitals within their limited capacity to initiate and promote organ donation. The Human Organ Act was passed in 1993 recognising brain stem death. According to this act, in order to remove organs from a person who has been declared death, permission must be obtained from the relatives. This act has now been amended recently (June, 2000) and all organs are included in the donor card. The Ministry of Health issues the donor cards and also started to print consent on the back of driving license.
FUTURE PLANS
The most important part of setting up of a tissue bank is a sustainable supply of donor materials. The long-term viability of a tissue bank depends upon whether or not it can obtain cadaveric donors. It is possible, however, that with efforts to promote sensible education programme and increase awareness, cadaveric tissue donation can be brought about to reality in Turkey. In the mean time, attention will be given to live donor materials.
CONCLUSION
During the project implementation, we think that we have achieved a significant progress in setting up a Tissue Bank. The building has been completed and arrangement with hospitals has been established to receive bone and amnion including blood test results. All equipment requested from the Agency have arrived and have been installed. The locally available equipment and consumable items have also been purchased and installed. The sufficient staffing level has been put in place and training programme has been completed. Processing procedures, setting up product design and implementation of quality system have been finalised. Now we come to the point of obtaining product license. We are also planning to supply limited number of grafts to the selected surgeons on trial basis. It can be concluded that the objectives of the project have been achieved successfully.
REFERENCES
1- MacEwan, W., “The osteogenic factors in the development and repair of bone”, Ann. Surg. 6, 289, (1887).
2- Eastlund, D. T., “The bank support for orthopedic surgery”, Orthopedic Transfusion Therapy, pp. 65-92, (1995).
3- Gopal, N. G. S., Nuclear India, Vol. 23, No. 6, p. 3 (1985).
4- Phillips, G.O., Multi-Media Distance Learning Package on Tissue Banking, Module 0: Historical Background, IAEA/NUS Regional Training Centre.
