Norimah Yusof

Gelam (Melaleuca spp.) Honey-Based Hydrogel as Burn Wound Dressing.

A novel cross-linked honey hydrogel dressing was developed by incorporating Malaysian honey into hydrogel dressing formulation, cross-linked and sterilized using electron beam irradiation (25 kGy). In this study, the physical properties of the prepared honey hydrogel and its wound healing efficacy on deep partial thickness burn wounds in rats were assessed. Skin samples were taken at 7, 14, 21, and 28 days after burn for histopathological and molecular evaluations. Application of honey hydrogel dressings significantly enhanced (P < 0.05) wound closure and accelerated the rate of re-epithelialization as compared to control hydrogel and OpSite film dressing. A significant decrease in inflammatory response was observed in honey hydrogel treated wounds as early as 7 days after burn (P < 0.05). Semiquantitative analysis using RT-PCR revealed that treatment with honey hydrogel significantly (P < 0.05) suppressed the expression of proinflammatory cytokines (IL-1α, IL-1β, and IL-6). The present study substantiates the potential efficacy of honey hydrogel dressings in accelerating burn wound healing.

Effect of freeze-drying and gamma irradiation on biomechanical properties of bovine pericardium

Freeze-drying and gamma irradiation are the techniques widely use in tissue banking for preservation and sterilization of tissue grafts respectively. However, the effect of these techniques on biomechanical properties of bovine pericardium is poorly known. A total of 300 strips of bovine pericardium each measured 4 cm × 1 cm were used in this study to evaluate the effect of freeze-drying on biomechanical properties of fresh bovine pericardium and the effect of gamma irradiation on biomechanical properties of freeze-dried bovine pericardium. The strips were divided into three equal groups, which consist of 100 strips each group. The three groups were fresh bovine pericardium, freeze-dried bovine pericardium and irradiated freeze-dried bovine pericardium. The biomechanical properties of the pericardial strips were measured by a computer controlled instron tensiometer while the strips thickness was measured by Mitutoyo thickness gauge. The results of the study revealed that freeze-drying has no significant (p > 0.05) effect on the tensile strength, Young’s modulus (stiffness) and elongation rate of fresh bovine pericardium. Irradiation with 25 kGy gamma rays caused significant decreased in the tensile strength, Young’s modulus and elongation rate of the freeze-dried pericardium. However, gamma irradiation has no significant effect on the thickness of freeze-dried bovine pericardium, while freeze-drying caused significant decreased in the thickness of the fresh bovine pericardium. The outcome of this study demonstrated that freeze-drying has no significant effect on the biomechanical properties of fresh bovine pericardium, and gamma irradiation caused significant effect on the biomechanical properties of freeze-dried bovine pericardium.

Sea cucumber (Stichopus hermanii) based hydrogel to treat burn wounds in rats

Malaysian sea cucumber was incorporated into hydrogel formulation by using electron beam irradiation technique and was introduced as novel cross-linked Gamat Hydrogel dressing. This study investigated whether Gamat Hydrogel enhanced repair of deep partial skin thickness burn wound in rats and its possible mechanism. Wounds were treated with either Gamat Hydrogel, control hydrogel, OpSite® film dressing or left untreated. Skin samples were taken at 7, 14, 21, and 28 days post burn for histological and molecular evaluations. Gamat Hydrogel markedly enhanced wound contraction and improved histological reorganization of the regenerating tissue. Furthermore, the dressing modulated the inflammatory responses, stimulated the activation and proliferation of fibroblasts, and enhanced rapid production of collagen fiber network with a consequently shorter healing time. The level of proinflammatory cytokines; IL-1α, IL-1β, and IL-6, were significantly reduced in Gamat Hydrogel treated wounds compared with other groups as assessed by reverse transcription-polymerase chain reaction (RT-PCR). In summary, our results showed that Gamat Hydrogel promoted burn wound repair via a complex mechanism involving stimulation of tissue regeneration and regulation of pro-inflammatory cytokines. The resultant wound healing effects were attributed to the synergistic effect of the hydrogel matrix and incorporated sea cucumber.

Bioburden Estimation in Relation to Tissue Product Quality and Radiation dose Validation

ABSTRACT Estimation of low bioburden or population of less than 100 viable microorganisms on amnion and bone allograft product is best measured by using a filtration method. From our routine quality control checks over several years, we found that the bioburden was reduced further after the tissues were properly handled and processed by trained staff with many years of experience. Bioburden of air-dried amnion was reduced to less than 100 cfu per item while bone showed bioburden around 10 cfu per item. Sterilisation dose validation exercises, carried out according to the three methods described in IAEA Code of Practices, requires skilled personnel with experience in conducting sterility test and dose mapping.

A Review of the International Atomic Energy Agency (IAEA) Code of Practice for the Radiation Sterilisation of Tissue Allografts

The code of practice adopted by the IAEA sets out the main requirements to ensure that the radiation sterilisation of tissues produces sterilised tissue allografts suitable for safe clinical use. The IAEA main contribution to the process of tissue sterilisation is the development of the guideline in using radiation for tissue. Sterilising tissue grafts using ionising radiation which is being used in many countries, offers a clear advantage in terms of safety compared with other sterilisation techniques for health care products and medical devices.

The impact of the International Atomic Energy Agency (IAEA) program on radiation and tissue banking in Malaysia

The IAEA was instrumental in developing the first Malaysian tissue bank at University Hospital of Universiti Sains Malaysia (HUSM), Kubang Kerian, Kelantan in early 1990s and it was officiated as National Tissue Bank in 1994. Up to date, 38 government and private hospitals have received a supply from the bank. Bone allografts in term of bone chips, morsalised bone and long bones are procured from Malaysian donors. Almost thirty students from Malaysia graduated in the training courses carried out in Singapore since 1998 at regional and interregional levels. Organ donation is more readily accepted by the public at the moments, perhaps due to the vast promotion and advertisement given by the local newspapers and other media, but gradually tissue donation is catching up as well.

Report on the 5th World Congress on Tissue Banking (WCTB 08) in conjunction with the 12th International Conference of Asia Pacific Association of Surgical Tissue Banks

The 5th World Congress on Tissue Banking (WCTB 08) in conjunction with the 12th International Conference of Asia Pacific Association of Surgical Tissue Banks was held from 2nd to 6th June 2008 at Renaissance Kuala Lumpur, Malaysia with the theme What’s New in Tissue Banking. The congress was attended by 280 delegates from 27 countries around the globe including prominent surgeons, renowned scientists, tissue bankers, tissue and organ transplant coordinators, regulators, researchers and students. Two pre-congress workshops were successfully conducted by prominent facilitators on 2nd June 2008. The radiation sterilization of tissue grafts workshop highlighted the important role of radiation technology in sterilizing tissue allografts for safe clinical use. There is a general interest among tissue bankers to use low dose gamma irradiation in combination with effective cleaning technologies. The tissue donor co-ordination and procurement workshop emphasized and discussed the processes involved in tissue donation. The participants were able to share their experiences in Australia, Malaysia, Singapore and Thailand. The congress itself which was held for 3 days from 3rd to 5th June 2008 witnessed a convergence of great minds in tissue banking. Experts in various areas of tissue banking, from the American Association of Tissue Banks (AATB), the Australasian Tissue Banking Forum (ATBF), the European Association of Tissue Banks (EATB), the Latin American Association of Tissue Banks (ALABAT) and the Asia Pacific Association of Surgical Tissue Banks (APASTB) presented and shared their latest research and clinical findings in three special lectures, seven plenary lectures and 11 symposia. Seven papers and 44 posters were presented during the young investigator award symposium and poster session, respectively. Two young investigator awards (fundamental and clinical category) and three best poster awards were given during the closing ceremony. The President, Dr. Astrid Lobo Gajiwala, India, on behalf of APASTB, also conferred APASTB honorary membership to Dr. Rudiger von Versen, Germany, and Dr. Douglas Michael Strong, USA, for their contribution to the APASTB during the past two decades. The Congress provided a useful forum not only for discussion on various clinical and scientific updates but also offered an opportunity for all participants to explore deeper the ethics of tissue banking and transplantation, regulatory frameworks and policy development. During the congress 30 exhibitors from S. Sheikh Ab. Hamid (&) Tissue Bank, Universiti Sains Malaysia, Kubang Kerian, Kota Bharu 16150, Kelantan, Malaysia e-mail: suzina@kb.usm.my