Skin donors and human skin allografts: evaluation of an 11-year practice and discard in a referral tissue bank

The Saint Louis hospital tissue bank provides skin allografts to pediatric and adult burn units in the Paris area. The aim of this study was to analyze our activity during the last 11 years focusing on the reasons for skin discard. Skin is procured solely from the back of the body, which is divided into 10 zones that are harvested and processed separately. This retrospective study included all skin donors harvested between June 2002 and June 2013, representing a total of 336 donors and 2770 zones. The donors were multiorgan heart-beating donors in 91 % of cases (n = 307). The main reason for discarding harvested skin was microbial contamination, detected in 99 donors (29 %). Most contaminants were of low pathogenicity. Other reasons for discard included positive serologic tests for 2 donors [17 zones (0.61 %)], unsuitable physical skin characteristics for 3 zones (0.11 %), the donor’s medical history for 53 zones (1.91 %), and technical issues with processing or distribution for 61 zones (2.2 %). In our experience, microbial contamination continues to be the main reason for discarding potential skin allografts. However, discards are limited by separate harvesting and processing of multiple zones in each donor.     

Bacterial infection transmitted by human tissue allograft transplantation

Bacterial contamination of tissue allografts obtained from cadaveric donors has been a serious cause of morbidity and mortality in recipients. Recent cases of fatal and nonfatal bacterial infections in recipients of contaminated articular cartilage (distal femur) and tendon allografts have called attention to the importance of avoiding tissue donors suspected of carrying infectious disease, of not processing donated tissue carrying virulent bacteria, the occurrence of falsely negative final sterility tests, and the need to sterilize tissues. These cases demonstrated that contamination can arise from an infected donor, during tissue removal from cadaveric donors, from the processing environment, and from contaminated supplies and reagents used during processing. Final sterility testing can be unreliable, especially when antibiotics remain on tissues. There is an increasing need for control of microbial contamination in tissue banks, and sterilization of tissue allografts should be recommended whenever possible.     

Analysis of potential factors affecting allografts contamination at retrieval

The microbiological contamination of retrieved tissues has become a very important topic and it is a critical aspect in the safety of allografts, especially from multi-tissue donors whose tissues are frequently contaminated as a consequence of retrieval. We analysed a total of 10,107 tissues, 8178 musculoskeletal and 1929 cardiovascular tissues, retrieved from 978 multi-tissue donors. Of these, 159 heart-beating donors (HBD) were also organ donors, while the remaining 819 non-heart-beating donors (NHBD) were tissue donors only. A multivariate logistic model was used to determine the factors affecting contamination risk during retrieval. In the model, the dependent variable was the presence/absence of contamination while the covariates included were: gender, type of donor, age of donor, cause of death, previous skin donation, cadaver time, number of people attending the retrieval, number of tissues retrieved. Moreover, a second log-linear model was used to determine the number of strains isolated per tissue. Tissue contamination was statistically correlated with gender, type of donor, cadaver time, number of people attending the retrieval and season. In conclusion, to minimize the risk of bacterial contamination, aseptic techniques should be used at retrieval, with the number of retrieval team members kept to a minimum. In addition, cadaver time should be as short as possible and the donor should be refrigerated within a few hours after death.     

Skin allograft procurement and transplantation in Mashhad,Iran: Are burn patients’ needs being met?

Only a single donor’s tissue may save or improve lives of one hundred patients. Unfortunately, low governmental and media support of tissue procurement and transplantation programs is a worldwide problem. Loss of an effective tissue procurement program in many countries like Iran, may lead to loss of many thousands valuable tissues each year. To evaluate the rate of skin donation in Mashhad in comparison to other organs and tissues, we extracted the data related to tissue and organ procurement in Mashhad from 2001. Then we evaluated the annual skin allograft needs in the Burn Department of Imam Reza Hospital as the only referral burn center in the northeast of Iran. Brain dead potential donation rate per million populations of Mashhad in the years 2007–2014 was about 33. The mean refusal rate was 51%. Of patients who have consent for donation, more than 86% have consent for skin donation. Skin allograft procured from 119 (35.5%) candidates. Average of skin retrieval per cadaveric was 1525 cm² with a gradual increase from 1400 cm² in the first year to 1800 cm² in the last year. The recipient to donor ratio was 1.14. It is estimated that about 1 cm² of skin allograft is needed for any cm² burnt body surface area. Considering more than 700 acute burn hospitalization in our burn unit, the patients need for skin allograft would be more than 3.5 million cm², annually. The annual amount of skin procurement in Mashhad has been currently about 20,000 cm². It shows that our patients demand is higher than supply. Skin procurement and transplantation is a simple procedure which can be as lifesaving as organ procurement and transplantation. But there isn’t any national organization to regulate tissue procurement, banking and transplantation. Governmental support of skin procurement and transplantation programs especially nonprofit programs may improve skin procurement rate and save more lives of severely burnt patients.     

Implementation of Organ Culture storage of donor corneas: a 3 year study of its impact on the corneal transplant wait list at the Lions New South Wales Eye Bank

Organ Culture corneal storage offers an extended storage time and increased donor pool and tissue assessment opportunities. In September 2011, the Lions New South Wales Eye Bank (LNSWEB) moved from hypothermic storage to Organ Culture corneal storage. This study evaluates the impact of implementation of Organ Culture on donor eye retrieval and the corneal transplant waiting list over a 3 year period in NSW, Australia. Retrospective review of the LNSWEB data from September 2011 to August 2014. Tissue collection, waiting list and tissue utilization data were recorded. The data from September 2008 to August 2011 for Optisol-GS storage was used for comparison. The annual donor and cornea collection rate increased 35 % and 44 % respectively with Organ Culture compared to Optisol-GS storage. The utilization rate of corneal tissue increased from 73.4 % with hypothermic storage to 77.2 % with Organ Culture storage. The transplant wait list decreased by 77.3 % from September 2011 to August 2014 and correlated with the increased rate of corneal transplantation (r = ?0.9381, p < 0.0001). No other factors impacting the wait list changed over this period. Corneas not used from either storage method were due to unacceptable endothelial cell density/viability. The contamination rate of corneas stored in Organ Culture medium was low at 1.74 %. The Organ Culture storage method increases the corneal donor pool available to Eye banks. The practical benefits of the extended storage time and increased donor assessment opportunities have directly led to an increase in corneal utilization rate and a significant decrease in recipient wait list time.     

Analysis of the effectiveness of Sodium Hypochlorite decontamination of cadaveric human tissues at retrieval

Bacterial contamination of tissues retrieved from cadaveric donors is a common feature worldwide, and every tissue bank, albeit using different methods, conducts decontamination to guarantee safe tissues suitable for clinical use. The effectiveness of the methods used to eradicate pathogens differs. In order to reduce the tissue bioburden at retrieval, we have introduced a new method involving rinsing tissues in a sodium hypochlorite solution. To test its effectiveness we analyzed two comparable groups of tissues: Group A: 1881 tissues, all rinsed with isotonic saline solution after retrieval, and Group B: 1968 tissues immersed in an isotonic saline solution containing sodium hypochlorite (final concentration 0.1 %) for different lengths of time and subsequently rinsed with isotonic saline. The rinsing solution of each tissue was then sampled for microbiological cultures in both groups. The resultant overall contamination rate was 40.5 % for Group A and 6.7 % for Group B, with an 82.8 % difference in the reduction of contamination between the two groups. This was especially the case for commensal skin bacteria in musculoskeletal tissue, which accounted for over half the overall contamination. Our data highlighted that decontamination with sodium hypochlorite was helpful in reducing the bacterial bioburden in tissues retrieved from cadaveric donors.     

Bacteriology testing of cardiovascular tissues: comparison of transport solution versus tissue testing

Bacteriology testing is mandatory for quality control of recovered cardiovascular allografts (CVA). In this paper, two different bacteriology examinations (A tests) performed before tissue antibiotic decontamination were compared: transport solution filtration analysis (A1) and tissue fragment direct incubation (A2). For this purpose, 521 CVA (326 heart and 195 artery tissues) from 280 donors were collected and analyzed by the European Homograft Bank (EHB). Transport solution (A1) tested positive in 43.25 % of hearts and in 48.21 % of arteries, whereas the tissue samples (A2) tested positive in 38.34 % of hearts and 33.85 % of arteries. The main species identified in both A1 and A2 were Staphylococcus spp. in 55 and 26 % of cases, and Propionibacterium spp. in 8 and 19 %, respectively. Mismatches in bacteriology results between both initial tests A1 and A2 were found. 18.40 % of the heart valves were identified as positive by A1 whilst 13.50 % were considered positive by A2. For arteries, 20.51 % of cases were positive in A1 and negative in A2, and just 6.15 % of artery allografts presented contamination in the A2 test but were considered negative for the A1 test. Comparison between each A test with the B and C tests after antibiotic treatment of the allograft was also performed. A total decontamination rate of 70.8 % of initial positive A tests was obtained. Due to the described mismatches and different bacteria identification percentage, utilization of both A tests should be implemented in tissue banks in order to avoid false negatives.     

Are all tissue donors recognised? A cohort study in three Dutch hospitals

Nowadays, the demand for tissue transplantation has significantly increased. To optimize donor recruitment, the potential availability of tissue donors has to be evaluated. In 2011 we conducted a cohort study in three Dutch hospitals in the Netherlands. The potential amount of eligible tissue donors found, based on medical records in these hospitals is compared to the physician’s donation form report. In total 1,342 patient records were analysed. From these records, the donation officers considered 484 patients as a potential tissue donor (36.1 %). Despite the absence of contra-indication, the physician did not recognise 25 % (n = 123/484) of potential tissue donors. Physicians’ lack of sufficient knowledge of tissue donation was the main cause of adequately identifying tissue donors. A higher percentage of tissue donors in these Dutch hospitals should be feasible through creating awareness and education regarding tissue donation.     

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

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 VD _max ²⁵ 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 %).     

Swab or biopsy samples for bioburden testing of allograft musculoskeletal tissue?

Swab and biopsy samples of allograft musculoskeletal tissue are most commonly collected by tissue banks for bacterial and fungal bioburden testing. An in vitro study was performed using the National Committee for Clinical Laboratory Standards standard ‘Quality control of microbiological transport systems’ (2003) to validate and evaluate the recovery of six challenge organisms from swab and biopsy samples of allograft musculoskeletal tissue. On average, 8.4 to >100 and 7.2 to >100 % of the inoculum was recovered from swab and biopsy samples respectively. A retrospective review of donor episodes was also performed, consisting of paired swab and biopsy samples received in this laboratory during the period 2001–2012. Samples of allograft femoral heads were collected from living donors during hip operations. From the 3,859 donor episodes received, 21 paired swab and biopsy samples each recovered an isolate, 247 swab samples only and 79 biopsy samples only were culture positive. Low numbers of challenge organisms were recovered from inoculated swab and biopsy samples in the in vitro study and validated their use for bioburden testing of allograft musculoskeletal tissue. Skin commensals were the most common group of organisms isolated during a 12-year retrospective review of paired swab and biopsy samples from living donor allograft femoral heads. Paired swab and biopsy samples are a suitable representative sample of allograft musculoskeletal tissue for bioburden testing.     

Residual Antibiotics in Decontaminated Human Cardiovascular Tissues Intended for Transplantation and Risk of Falsely Negative Microbiological Analyses

We investigated the presence of antibiotics in cryopreserved cardiovascular tissues and cryopreservation media, after tissue decontamination with antibiotic cocktails, and the impact of antibiotic residues on standard tissue bank microbiological analyses. Sixteen cardiovascular tissues were decontaminated with bank-prepared cocktails and cryopreserved by two different tissue banks according to their standard operating procedures. Before and after decontamination, samples underwent microbiological analysis by standard tissue bank methods. Cryopreserved samples were tested again with and without the removal of antibiotic residues using a RESEP tube, after thawing. Presence of antibiotics in tissue homogenates and processing liquids was determined by a modified agar diffusion test. All cryopreserved tissue homogenates and cryopreservation media induced important inhibition zones on both Staphylococcus aureus- and Pseudomonas aeruginosa-seeded plates, immediately after thawing and at the end of the sterility test. The RESEP tube treatment markedly reduced or totally eliminated the antimicrobial activity of tested tissues and media. Based on standard tissue bank analysis, 50% of tissues were found positive for bacteria and/or fungi, before decontamination and 2 out of 16 tested samples (13%) still contained microorganisms after decontamination. After thawing, none of the 16 cryopreserved samples resulted positive with direct inoculum method. When the same samples were tested after removal of antibiotic residues, 8 out of 16 (50%) were contaminated. Antibiotic residues present in tissue allografts and processing liquids after decontamination may mask microbial contamination during microbiological analysis performed with standard tissue bank methods, thus resulting in false negatives.     

Distribution of potential eye and tissue donors within an Australian teaching hospital

Eye and Tissue donation has the capacity to transform lives, yet the vast majority of potential in-hospital donors are not recognised. Studies which describe the relative importance of specific units or wards in determining the size of the donor pool are limited. The aim of this study was to map the distribution of potential Eye and Tissue donors within the study hospital. A 12-month retrospective analysis of all patient deaths at the study hospital was undertaken. The ability to donate corneal, heart valve, bone and skin tissue was investigated. Patients were classified as potential donors if they met specific age criteria and had an absence of contraindications based on electronic database search. There were 985 deaths during the study period. Deaths occurred under the care of 26 separate clinical units, and within 28 unique wards and treatment spaces. Four hundred and forty nine (45.6%) patients were identified as potential eye or tissue donors. The majority of potential donors occurred in ICU, Emergency and palliative care units. Of the subset of 328 deaths ≤ 70 years, the frequency of potential tissue donors was 55% (n = 181). ED and ICU had significantly higher frequencies of potential donor than other wards (86 and 77%, p < 0.01). The current study has identified the ED, ICU and PCUs are being important sites for potential Eye and Tissue Donors within our hospital. These will provide an important focus for future interventions to improve the rate of eye and tissue donation.     

Prevalence and level of Listeria monocytogenes and other Listeria sp. in ready-to-eat minimally processed and refrigerated vegetables

Minimally processed and refrigerated vegetables can be contaminated with Listeria species bacteria including Listeria monocytogenes due to extensive handling during processing or by cross contamination from the processing environment. The objective of this study was to examine the microbiological quality of ready-to-eat minimally processed and refrigerated vegetables from supermarkets in Osijek, Croatia. 100 samples of ready-to-eat vegetables collected from different supermarkets in Osijek, Croatia, were analyzed for presence of Listeria species and Listeria monocytogenes. The collected samples were cut iceberg lettuces (24 samples), other leafy vegetables (11 samples), delicatessen salads (23 samples), cabbage salads (19 samples), salads from mixed (17 samples) and root vegetables (6 samples). Listeria species was found in 20 samples (20 %) and Listeria monocytogenes was detected in only 1 sample (1 %) of cut red cabbage (less than 100 CFU/g). According to Croatian and EU microbiological criteria these results are satisfactory. However, the presence of Listeria species and Listeria monocytogenes indicates poor hygiene quality. The study showed that these products are often improperly labeled, since 24 % of analyzed samples lacked information about shelf life, and 60 % of samples lacked information about storage conditions. With regard to these facts, cold chain abruption with extended use after expiration date is a probable scenario. Therefore, the microbiological risk for consumers of ready-to-eat minimally processed and refrigerated vegetables is not completely eliminated.     

Analysis of predisposing factors for contamination of bone and tendon allografts

Bone and tissue allografts are widely used in transplantation. The increasing demand for safe allografts must be met, while minimizing disease transmission. We analysed the incidence and potential risk factors of allograft contamination and the effectiveness of disinfection, by reviewing 22 years of tissue bank activity and 474 donor procurements. We also compared different disinfection procedures used over the 22 years. The overall contamination rate was 10.1%. Risk factors were related to the donor or procurement method. Immediate culture at the tissue recovery site diminished the rate of false positives by reducing later sample manipulation. High-virulence allograft contamination was mainly related to donor factors, while low-virulence contamination was related to procurement methods. Analysis of donor-related risk factors showed no statistical differences for age, sex, or cause of death. An intensive care unit stay was associated with less contamination with high-virulence microbes. Procurement in a setting other than an operating theatre was associated with higher contamination rate. Team experience reduced contamination. Pelvic and tendon allografts were most frequently contaminated. Proper disinfection considerably reduced the contamination rate to 3.6%. We conclude that procurement must be performed under aseptic conditions, with short delays, and by trained personnel. Grafts should be disinfected and packed as soon as possible.     

Combined chlorhexidine and PVP-I decontamination of human donor eyes prior to corneal preservation

The aim of this study was to report the efficacy of adding chlorhexidine to the protocol for decontamination of human donor globes prior to excision of corneo-scleral rims for future keratoplasty procedures. In 2005, chlorhexidine was introduced by our eye bank as an additional step in the protocol for decontaminating human donor globes. After 5?years, we prospectively evaluated the number of contaminations. Out of 2,891 globes included in our study, 2,663 globes were processed, of which 36 (1.4%) were considered contaminated. Seventeen contaminations (0.6%) were detected by culturing limbal swabs, directly after decontamination, eight (0.3%) by visible discoloration of the culture medium carrying a corneo-scleral rim, and eleven (0.4%) after inoculation of the culture medium on blood agar plates. Importantly, after 4?weeks of incubation, none of the aerobic and anaerobic cultures taken from the secondary ??transport medium?? (dextran containing medium used to transport corneal tissue to the transplantation centre) showed microbiological growth. In conclusion, the combined use of 0.02% chlorhexidine and 0.5% povidone-iodine may allow decontamination of donor globes to a level at which the risk of tissue contamination at the time of transplantation is minimized, while corneal viability is preserved.     

Correlates of professional burnout in a sample of employees of cell and tissue banks in Poland

Job Demands-Resources model proposes that the development of burnout follows excessive job demands and lack of job resources. Job demands are predictive of feeling of exhaustion, and lack of job resources—disengagement from work. This pilot study investigated professional burnout and its correlates in employees of Polish cell and tissue banks, many of whom were involved in procurement and processing of tissues from deceased donors, as it was hypothesized that job burnout in this population might influence the effectiveness of cell and tissue transplantation network in our country. This study utilized the Polish version of the Oldenburg Burnout Inventory (OLBI), which measures the two dimensions of burnout (exhaustion and disengagement), and the Psychosocial Working Conditions Questionnaire (PWC), a Polish instrument used for monitoring psychosocial stress at work. The study sample consisted of 31 participants. Their average time of working in a cell and tissue bank was 13.20 years. Majority of the PWC scales and subscales scores fell in the Average range, and the OLBI results for the Disengagement and the Exhaustion scales were in the Average range. A number of correlations between the Exhaustion or Disengagement and the PWC scales and subscales were detected, majority of which fell in the Moderate range. In spite of the limited number of participants, the results of this pilot study are consistent with the burnout literature reports. Among the detected correlates of professional burnout, it is job-related support which seems to be the most important factor which may influence the efficacy of transplantation network in Poland.     

The Tissue Bank at the National Nuclear Research Institute in Mexico

The Instituto Nacional de Investigaciones Nucleares (ININ, The National Nuclear Research Institute) received during 1997-1998 strong support of the International Atomic Energy Agency (IAEA), to establish the first and only one tissue bank (BTR ININ tissue bank) in Mexico that uses ionising radiation as sterilising agent. In that time, the BTR staff was trained in different tissue banks in several countries. Basic equipment for tissue processing donated by the IAEA was received in 1998. In July, 1999 the Mexican Health Secretariat gave the Sanitary License No. 1062000001 to the BTR to operate as an official organ and tissue bank. In August, 2001 the ININ and the Hospital Materno Infantil (HMI-ISSEMYM) signed an agreement to collaborate in amnion processing. The hospital is responsible for donor selection, serology tests, tissue procurement and washing, since this hospital is the BTR amnion supplier. The tissues are collected by ININ weekly with complete documentation. The BTR is responsible for processing: cleaning, air drying, packaging, labelling, microbiological control and sterilisation by gamma irradiation. The sterilised tissue is kept under quarantine for 6 months to obtain the results of the donor second serology test. From March to June, 2002 the BTR has processed 347.86 units (50 cm(2) each), is say, 17,393 cm(2). In addition, the pig skin xenograft process has been implemented and a protocol for clinical applications of it is running at the Hospital Central Sur de Alta Especialidad (PEMEX). Also the ININ tissue bank present status and perspectives are described.     

Desulfovibrio vulgaris Hildenborough prefers lactate over hydrogen as electron donor

Desulfovibrio vulgaris can use lactate as an electron donor and accumulate hydrogen. Hydrogen can also be consumed as an electron donor when lactate is depleted or absent. The aim of this study was to determine whether D. vulgaris has an electron donor preference system between lactate and hydrogen and how this system is regulated. In order to be sure that D. vulgaris was grown under the same conditions except for electron donors, continuous growth mode was conducted and the optical density (600 nm) was kept constant. When 20 mmol/l lactate was the sole electron donor, it was depleted after 9 h of incubation while hydrogen was accumulated to 1,500 ppm. After that, the hydrogen level was decreased to and maintained at 400 ppm. When 1,200 ppm hydrogen was provided as the electron donor, the culture reached an OD of 0.2 after 24 h incubation and hydrogen was consumed to 600 ppm. When 1,200 ppm hydrogen and 20 mmol/l lactate were both present, the lactate was consumed during the first 9 h incubation and hydrogen was accumulated to 1,800 ppm. D. vulgaris used hydrogen as an electron donor after the lactate was depleted and the hydrogen level was decreased to 600 ppm. D. vulgaris has both pathways to utilize lactate and hydrogen as electron donors. It prefers lactate over hydrogen and the system is regulated by lactate starvation.     

Broth versus solid agar culture of swab samples of cadaveric allograft musculoskeletal tissue

As part of the donor assessment protocol, bioburden assessment must be performed on allograft musculoskeletal tissue samples collected at the time of tissue retrieval. Swab samples of musculoskeletal tissue allografts from cadaveric donors are received at the microbiology department of the South Eastern Area Laboratory Services (Australia) to determine the presence of bacteria and fungi. This study will review the isolation rate of organisms from solid agar and broth culture of swab samples of cadaveric allograft musculoskeletal tissue over a 6-year period, 2006–2011. Swabs were inoculated onto horse blood agar (anaerobic, 35 °C) and chocolate agar (CO₂, 35 °C) and then placed into a cooked meat broth (aerobic, 35 °C). A total of 1,912 swabs from 389 donors were received during the study period. 557 (29.1 %) swabs were culture positive with the isolation of 713 organisms, 249 (34.9 %) from solid agar culture and an additional 464 (65.1 %) from broth culture only. This study has shown that the broth culture of cadaveric allograft musculoskeletal swab samples recovered a greater amount of organisms than solid agar culture. Isolates such as Clostridium species and Staphylococcus aureus would not have been isolated from solid agar culture alone. Broth culture is an essential part of the bioburden assessment protocol of swab samples of cadaveric allograft musculoskeletal tissue in this laboratory.     

The importance of establishing an international network of tissue banks and regional tissue processing centers

During the past four decades, many tissue banks have been established across the world with the aim of supplying sterilized tissues for clinical use and research purposes. Between 1972 and 2005, the International Atomic Energy Agency supported the establishment of more than sixty of these tissue banks in Latin America and the Caribbean, Asia and the Pacific, Africa and Eastern Europe; promoted the use of the ionizing radiation technique for the sterilization of the processed tissues; and encouraged cooperation between the established tissue banks during the implementation of its program on radiation and tissue banking at national, regional and international levels. Taking into account that several of the established tissue banks have gained a rich experience in the procurement, processing, sterilization, storage, and medical use of sterilized tissues, it is time now to strengthen further international and regional cooperation among interested tissue banks located in different countries. The purpose of this cooperation is to share the experience gained by these banks in the procurement, processing, sterilization, storage, and used of different types of tissues in certain medical treatments and research activities. This could be done through the establishment of a network of tissue banks and a limited number of regional tissue processing centers in different regions of the world.