1. INTRODUCTION

   This workshop was co-sponsored by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan and the Ministry of Science and Technology (MOST), Vietnam. The Vietnam Atomic Energy Commission and Japan Atomic Energy Agency (JAEA) jointly executed the workshop in cooperation with the International Atomic Energy Agency (IAEA). The main objectives of the workshop were the following:

• to discuss for the promotion of the commercial applications of radiation processing of natural polymer
• to prepare the work plan for the FNCA activities for 2007-2008.

The FNCA project on the Application of Electron Accelerator was organized with the participation of nine FNCA countries. This is the seventh workshop of the project and the first one organized in collaboration with the IAEA/RCA Project. The workshop was attended by experts on application of electron accelerator, radiation processing of natural polymer from the FNCA participating countries: Bangladesh (1), China (1), Indonesia (1), Japan (11), Korea (1), Malaysia (2), the Philippines (1), Thailand (1) and Vietnam (7). In addition, IAEA/RCA Project Lead Country Coordinator (PLCC), Philippines and three experts representing non FNCA, RCA member countries namely India (1), Pakistan (1) and Sri Lanka (1) also participated in the workshop. Prof. El-Sayed Hegazy of Egypt attended the workshop under the invitation of IAEA to deliver a special paper on super water absorbent hydrogel. Annex 1 shows the list of participants.

On the first day, an open seminar on “Progress in Radiation Processing” was held and attended by 115 participants from industries, universities, research institutes and members of FNCA Workshop. An exhibition that consisted of posters and product display was held and participated by China, Japan, Indonesia, Korea, Malaysia and Vietnam.

At the opening session of the Open Seminar, Mr. Hiroki Matsuo, Director of MEXT, delivered the welcoming address. He thanked the Vietnam government for hosting the seminar and workshop. The opening address was delivered by Dr. Bui Van Quyen, General Director, Southern Office, Ministry of Science and Technology (MOST). He expressed his warm welcome to all participants and wished the successful deliberation and outcome of the seminar and workshop.

2. INVITED PAPERS

   Dr. Sueo Machi, FNCA Coordinator of Japan, presented a paper entitled “Role of Nuclear Technology for Sustainable Development in Asia”. In his paper, he presented the Nuclear for Mankind in terms of “Stable and Safe Energy Supply”, “Improvement of Health Care”, “Better Food Supply” and Efficient Industry”. He pointed out the importance of nuclear power for the non-emission of Green House Gases, no dependence on volatile oil/gas, fuel recycling, and energy mix with other energy. From the point of view of human health, he introduced the importance of accelerators (cyclotron) for the diagnosis of cancer. He emphasized the importance of radiation technology for the improvement of agricultural application. The importance of “Mutation Breeding”, “Sterile Insect Technique (SIT)”, “Animal Production”, “Soil Science-biofertilizer” and “Food Irradiation” was also discussed. Finally, he highlighted the radiation processing on polymer products and environmental protection for flue gas and waste water treatments.

3. LECTURES AT THE OPEN SEMINAR

   Dr. Tamikazu Kume, FNCA project leader of Japan, presented a paper on Introduction of Radiation processing. He introduced the importance of radiation processing on polymers, environmental conservation, sterilization of medical devices, radiation pasteurization and fermentation, sterile insect technology, mutation breeding, food irradiation and application for natural polymers.

   Dr. Quoc Hien Nguyen of VAEC presented a paper on “Radiation Processing in Vietnam” with special emphasis on natural polymers. An overview of the research and development works on radiation technology in Vietnam during the period of 2005-2007 was discussed. He described the irradiation facilities, staffs, R&D projects and international co-operations of VAEC. The recent results on application of natural polymers for super water absorbents and hydrogel wound dressings and future R & D plan were also presented.

   Dr. GuoZhong Wu of Chinese Academy of Science, China, presented a paper on “Radiation processing of Polymer in China”. He described the commercialized products in China such as heat-shrinkable materials and status of irradiation facilities. Their challenge of looking for new applications and future plans were discussed.

   Dr. Khairul Zaman of Nuclear Malaysia presented a paper on “Radiation Processing in Malaysia”. He focused on the radiation processing developed by Nuclear Malaysia. The irradiation facilities and the R & D program at Nuclear Malaysia were also presented. Nuclear Malaysia has established polymer processing laboratory and pilot plants. It has also succeeded in the technology transfer and commercialization of Sago starch hydrogel.

   Seven experts on each field presented other papers on specific applications. The papers presented are as follows;

   • Printing and Coating with Electron Accelerator” by Dr. Masakazu Washio,
   • Automobile Parts by Radiation Crosslinking” by Dr. Fumio Yoshii,
   • Production of Hydrogel Wound Dressing by Radiation” by Mr. Kazuki Isobe,
   • Industrial Application of Radiation Graft Polymerization” by Dr. Masao Tamada,
   • Radiation Processing of Starch” by Dr. Kamaruddin Hashim,
   • Chitin, Chitosan and Radiation by Dr. Seiichi Tokura, and
   • Radiation Processed Polysaccharides for Agricultural Application in Vietnam” by Dr. Hai Le.
4. Workshop

   The FNCA 2007 workshop was officiated by Mr. Tran Khac An, Director of Research and Development Center for Radiation Technology (VAEC). The workshop program was presented and adopted with the change of date for the technical visit from October 24th to 26th. The program of the workshop is given in Annex 2.

   4-1. Special Lecture of Dr. Sueo Machi
   Dr. S. Machi delivered a talk on “Perspective of FNCA and Project of Radiation Processing of Natural Polymers”. Firstly, he introduced the FNCA as the effective mechanism for enhancing socio-economic development through “Active regional partnership” in the peaceful and safe utilization of nuclear technology. In relation to the purpose of the project on “Radiation processing of natural polymers”, he stressed the importance of a single R&D team to achieve the goal in each country. Nevertheless, the importance of collaborations in Information Exchange, Sharing R&D work and Exchange of Scientist under the support of IAEA and MEXT is also pointed out. He emphasized the importance of strategy for commercialization in the viewpoint of “product properties”, “competitive cost” and “close collaboration with industries” for the market study, process and plant optimizations.

   4-2. Status Report by Dr. Tamikazu Kume
   Dr. T. Kume, FNCA project leader of Japan, presented an outline of the Application of Electron Accelerator for the FNCA EB projects Phase 1 and Phase 2. Phase 2 focuses on radiation processing of natural polymers which is three year project (2006-2008). It also includes the subject on economic evaluation. To synergize efforts, he further commented that the FNCA project on radiation processing of natural polymer has to cooperate with RCA of the same project.

   4-3. Session for Each Theme

   4-3-1. Summary Report on Session 1: Hydrogel Wound Dressing (HWD)

   Dr. Young-Chang Nho reported on “Radiation processing of hydrogel for wound dressing in Korea”. Two different formulations were used to prepare hydrogels. The first one uses PVP, PEG, carageenan and water as the starting materials, while the other one uses PVA and water. Through the cooperation with a company and a hospital, healing test of Cligel has been completed and the result was very good. The company has already received the production license from Korea Food and Drug Association and is now commercially available in the market. However, compared to polyurethane foam which is widely applied in hospitals of Korea, the capability of absorption of body fluid for Cligel is much lower and has to be improved. Some efforts were attempted to improve such absorption capability but failed. Hydrogels prepared by radiation crosslinking of PVA and herb extract was found to be useful for atopic dermatitis treatment. Dr. Nho also noted that impurity (sodium acetate) in PVA hydrogel has to be removed to obtain high quality product. He found that 95% of sodium acetate can be removed by washing with water.

   Dr. Khairul gave a presentation on “Pilot scale test and commercialization of sago hydrogel for face mask and wound dressing”. Malaysian Nuclear Agency has spent almost 10 years to develop sago starch based hydrogel for the fabrication of facial mask and wound dressing. Collaboration with private company for trial production of facial mask was initiated in 2003. The Good Manufacturing Practice (GMP) plant was built in November 2004 and which started operation in May 2005. The company may start full commercial production in 2008-2009. In the process of commercialization, they overcame a lot of difficulties in the construction of the production line. Compared to face mask, commercialization of wound dressing takes longer time.

   Ms. Lorna Relleve gave a presentation on ”Semi-commercialization of PVP-carrageenan hygrogel.” Philippines has developed PVP-carrageenan hydogel for burns and bedsore treatment by radiation crosslinking. In order to get better property, PEG was added into PVP/kappa carrageenan solution. Clinical test for burns and bedsore/ulcer has been completed. Results indicated that the effect of hydrogel is much better than saline gauze. Economic feasibility study and business plan were completed. Production of hydrogel for the use of wound dressing in semi-commercial scale may start in 2007-2008. It is expected to be fully commercialized in 2009.

   Dr. Suwanmala Phiriyatorn reported on “Radiation processing of cassava starch hydrogel wound dressing” in Thailand. PVP-grafted starch hydrogel was prepared in laboratory scale by irradiation of VP and starch. The grafting reaction was confirmed by FTIR, TGA, gel fraction analysis and swelling test. They also achieved crosslinked CMS by irradiation in the paste-like condition.

   Dr. Emdadul Haque of Bangladesh presented on: R&D utilization of indigenous materials for hydrogel wound dressing. They prepared hydrogel by two different formulations using PVP and PVA separately. Considering the price of the raw materials PVA was chosen and to reduce the cost of raw materials further flour was added to the PVA formulation. Ingredient concentrations for preparing good quality hydrogel were optimized. PVA containing 0.75% both of carragenaan and flour produces hydrogel with good quality. Demonstration of such hydrogel for wound dressing has been carried out in hospital. They also developed a method of coating chitosan onto surgical gauze for better application in medicine.

   4-3-2. Summary Report on Session 2: Super Water Absorbent (SWA)

   Prof. El-Sayed Ahmed Hegazy presented an invited lecture on “Super water absorbent hydrogel”. He mentioned that the research has been carried out for many years. The SWA is being used in personnel care, agriculture, medical and water purification. Polyacrylamide and polyacrylic acids are the synthetic polymers that are commonly used for production of super water absorbent hydrogel. Radiation crosslinked polyacrylamide can be used as soil conditioner since it has a very good property for water retention. This hydrogel has good advantage to be used as soil conditioner for sandy soil and which can retain water for three days. The addition of radiation degraded Na-alginate or Na-CMC to the crosslinked polyacrylamide hydrogel will give an “add on” application as plant growth promoter. Degradation dose for natural polymers (alginate and chitosan) was significantly reduced by the addition of ammonium persulphate during irradiation. Polyacrylic acid is currently being used in diapers and sanitary napkins. However, radiation crosslinked polyacrylamide containing CMC-Na with a foaming agent such as ammonium carbonate has been demonstrated to have good swelling ratio and water retention time. This material may be useful as commercial diapers.

   Dr. Binh Doan presented a paper on “Super Water Absorbent by Radiation Graft Polymerization of Acrylic Monomers onto Cassava Starch” in Vietnam. Starch grafted with acrylic acids at weight ratios of 1:1, 1:2 and 1:3 has also been shown to absorb a large amount of water of 200-500 times of its weight at an irradiation dose of 4.5 kGy and dose rate of 1.6 kGy/hr. This super water absorbent hydrogel is biodegradable and can be used as plant growth promoter and soil conditioner. This hydrogel can enhance the yield of crops such as maize, peanuts, coffee, cotton, etc., in between 10% to 30%.

   Dr. Yoshii presented a paper on “Effective Utilization of Agro-Waste by Application of CMC Dry-Gel”. Radiation crosslinked Na-CMC hydrogel is also used as super water absorbent. At 5.0 KGy, the Na-CMC hydrogel can swell 150 times of its original dry hydrogel weight in water. This can be used for excrement treatment of livestock, treatment of Shochu residue, improvement of strength and shrinkage of traditional Japan paper (Washi). Aside from the synthetic polymers e.g. polyacrylamide and polyacrylic acid utilized as superabsorbents, natural polymer such as radiation crosslinked Na-CMC and starch grafted with acrylic acids can also be used. These may find applications in agriculture as soil conditioner, healthcare product and for environmental conservation. Radiation degraded natural polymer can be added into super water absorbent hydrogel in order to make the hydrogel useful as plant growth promoter and as soil conditioner.

   4-3-3. Summary of Session 4: Plant Growth Promoter (PGP)

   Degradation of polysaccharides by radiation has been shown to induce biological activities for plant through enhancement of enzyme activity, antimicrobial activity, phytoalexin induction, promotion of growth and as heavy metal suppressor.

   Dr. Quang Luan reported on “Commercial Application of Radiation Degraded Alginate” in Vietnam. He presented his studies on the plant growth promoting effect of radiation degraded alginate and chitosan. Laboratory tests were carried out using tissue culture system on chrysanthemum, limonium and lisianthus. The dose for growth promoting effect of oligoalginate and oligochitosan varies with the plant ranging from 75-100 kGy Effect of survival ratio of transferred plantlets in a greenhouse was determined to be greater when plants were treated with oligochitosan. Commercialization and registration of the product involves the following steps in Vietnam: a) toxicity test b) trial certificate c) field testing and d) certificate for commercial application. The irradiated alginate T&D has been accepted for commercial application. Due to high dose of the degradation, synergistic effect may be introduced by the addition of some chemical reagent such as ammonium persulfate during irradiation of alginate. This results in reducing the dose significantly.

   Dr. Gatot Trimulyadi made a presentation on “Development and Field Test of Radiation Degraded Chitosan as Plant Growth Promoter” in Indonesia. He presented his studies on the plant growth promoting effect of irradiated chitosan. Hormonal analysis of the oligo-chitosan indicated the presence of hormones; auxin, cytokinin and gibberelic acid. These compounds are known to increase the root plant and decrease in the drop off of flowers. Field testing of oligo-chitosan was done on chilli, potato and carrot plants. Total harvest of these crops was compared to plant added with conventional chemical fertilizers. Results indicated a higher increase in yield of crops 31-34% in potato and 53-55% in carrot plant. The age for the plant for harvest also decreased: 3 months against 4 months in potato and 3.5 months against 5 months in carrot plants. Harvest time in chilli decreased from 6 to 5 months. Economic feasibility studies of the application of oligo-chitosan in chilli plant indicated a positive ROI of 249.11 vs 146.32 for the conventional fertilizer.

   Dr. Phiriyatorn gave a presentation on “Progress on Agricultural Application of Degraded Chitosan in Thailand” She presented her laboratory scale studies on the plant growth promoting effect of irradiated chitosan. Oligo-chitosan was applied to lettuce, Amaranthus (Chinese spinach) and Kale. Optimum biological effects were determined as follows: oligo-chitosan with molecular weights (Mv) of 20 kDa for lettuce, 8-12 kDa for Chinese spinach and 8 kDa for kale.

   Discussion

   The following issues and concerns were raised during the discussion:

   • The need to have a detailed protocol for the production of oligo-chitosan.
   • The need to have a detailed protocol for applying oligo-chitosan in the field.
   • The synergistic effect of PGP and chemical fertilizers has to be evaluated.
   • Radiation could compete with the conventional chemical fertilizers as plant growth promoter by using additives to reduce degradation dose.
   • The economic feasibility studies of PGP in Indonesia and Vietnam have to be compared.
   • Oligo-chitosan when labelled as elicitor would have a higher economic value than when labelled as PGP.
   • Field testing of oligo-chitosan elicitor among member states (samples and protocol for application to be provided by Vietnam) would facilitate the transfer of technology.
   • Radiation technology is considered the most effective method for producing oligo-saccharide (chitosan, alginate etc.) for sustainable development in agriculture.

   4-3-4. Summary Report of Session 5: Other Application of Radiation Processed Natural Polymer

   Dr. Wu presented a paper on “Application of Radiation Degraded Chitosan in Aquaculture”. China has utilized radiation degraded chitosan in aquaculture and animal feed. Chitosan aqueous solution and chitosan/I2 complex solution have been successfully applied in aquaculture. The main functions of chitosan solution are to clean water and prevent fish/shrimp from infection of disease. In 2007, about 100 tons of chitosan solution has been sold by the contracted companies. Radiation-degraded chitosan has been applied in animal feed as an additive to enhance immunity of animals. The tested animals include fish, pig, cow, and chicken. In all cases the addition of chitosan showed very positive results. It was found that the addition of 50 ppm radiation-degraded chitosan is enough to feed chicken and fish. For weaned pig and cow, a dose of 200-300 ppm chitosan is required. Direct injection of water soluble chitosan into udder of cow has also been tested to cure marstitis. In China, chitosan micropowder is prepared by a combination of irradiation and milling. The micropowder has been applied for the fabrication of antibacterial viscose fiber.

   Ms. Relleve presented a paper on “PVP-chitosan Hydrogel for Implant”. Vesicoureteral reflux (VUR) refers to the retrograde flow of urine from the bladder into the upper urinary tract. It predisposes an individual to renal infection by facilitating the transport of bacteria from the bladder to the upper urinary tract. Endoscopic treatment of VUR has gained favor in recent years as a therapeutic alternative to long-term antibiotic prophylaxis and open surgery in 90% of cases. To date, endoscopic treatment has mainly been performed with the use of implants like polytetrafluoroethylene, silicone, cross-linked bovine collagen, polydimethysiloxane, and autologous chondrocytes but safety and efficacy concerns have precluded their widespread use. A new implant was developed from PVP-Chitosan implant prepared and sterilized by gamma-irradiation for endoscopic treatment of VUR. The implant has been tested in animal at the University of Santo Tomas Hospital (UST), Philippines and was compared to control, Deflux. Deflux is the only substance cleared by FDA for treatment of VUR. PVP-Chitosan hydrogel showed promising result as a possible ideal tissue augmenting implant. It maintained its viscosity enough to allow easy injection to as small as G26 needle. Animal testing shows that the implant is stable over time, biocompatible and non-migratory. Clinical trials of this implant have to comply with the strict policy of the UST Hospital ethics committee.

   Dr. Nho presented a paper on “Metal Adsorbent by Carboxymethyl Chitosan Hydrogel. Metal ion adsorbent has practically been used for exchange and the removal of toxic ions such as lead and cadmium. Such commercialized adsorbent resins are generally synthesized by copolymerizing the precursor monomer, chloromethystyrene, and crosslinker, divinylbenzene. For the shortage of petroleum resources and to decrease environmental burden, the natural occurring polymers should be used as raw materials for metal ion adsorbents. Carboxymethylated chitin and chitosan (CMCht and CMChts) are naturally occurring-based materials. It is found that these materials could be crosslinked with high energy irradiation at their past-like state. The enzyme degradabilities of CMCht and CMChts are maintained even after their crosslinking. In the soil burial test, the degradation of both hydrogels were confirmed. Microbial oxidative degradation has revealed that radiation crosslinked hydrogels of CMCht and CMChts degrade slightly faster than unirradiated CMCht and CMChts. This may be due to the decrease in molecular weight of chitin and chitosan. CMCht hydrogel adsorbed Pd, Sc, Au, Cd, V, and Pt while CMChts adsorbed Au and Pt. The maximum capacities for Au were 53.3 and 39 μ mol/g for CMCht and CMChts hydrogels, respectively. The adsorbed gold ions on hydrogel were quantitatively eluted by HCl solution. Hence, these hydrogels of CMCht and CMChts have the possibility for recovery of noble metals in treatment of industrial waste water.

   During the discussion, the following points were raised:

   • hydrogels of CMCht and CMChts can be applied in the recovery of noble metals from industrial waste water.
   • radiation degraded chitosan can be effectively used in aquaculture and animal feed.
   • PVP-Chitosan hydrogel shows promising result as a possible ideal tissue augmenting implant

   4-3-5 Summary Report of Session 3. Activities and Achievement of RCA

   Ms. Lucille Abad reported the activities and achievement of IAEA RCA project under RAS/8/098 for 2005-2006 and RAS/8/106 for 2007-2008. Most of the research activities that are being carried out under the FNCA Program are also being carried out under the IAEA RCA program. However, the IAEA RCA program includes regional and national training course, fellowship attachment, scientific visit and expert mission aside from the research activities. India, Pakistan and Sri Lanka as representative of the RCA countries have also reported their activities and achievements on the application of radiation processing of natural polymer for wound dressing, fruit preservation, plant growth promoter, metal adsorbent and treatment of animal excretion using hydrogel and super water absorbent hydrogel made of chitosan, carrageenan and CMC.

5. Technical Visit

   Workshop participants visited Research and Development Center for Radiation Technology (VINAGAMMA), Vietnam Atomic Energy Commission (VAEC). They were received Mr. Tran Khac AN Director, of the center. The participants were briefed on the center profile, their products and processes. The participants were later taken for tour of the Cobalt 60 irradiation facility and a pilot plant for manufacturing Super Water Absorbent.

6. Discussion on Future Plan

   6-1. Preparation of Guideline
   The FNCA Guidelines on Development of Hydrogel and Oligosaccharides by Radiation Processing have been presented by Dr. Hisaaki Kudo.

   The outline of the document was presented. Submission for some technical details, cost analyses and revision of current progresses for each country has been requested. A request was also made to fill in the “Format Sheets” which will be submitted to Dr. Keizo Makuuchi or Dr. Kudo before the end of December 2007.

   6-2. proposal for workshop in 2008
   Dr. Wu proposed the coming workshop to be held in Shanghai, China, in 2008. All FNCA member countries agreed with the proposal. The workshop will be held in autumn 2008 and the details of the workshop will be decided later. The main theme for the next workshop will be on technology transfer. The future plan of the FNCA project and special topic on aquaculture will be discussed. As the next workshop will be the final year of the current FNCA project (2006 -2008), evaluation of the project needs to be discussed.

   6-3 Future plan

   1. The meeting agreed that there is a need to synergize the activities of radiation processing of natural polymer under the FNCA and RCA to avoid duplication. In this connection, it was further emphasized that in every FNCA and RCA member countries, there should be only one research team on this field.
   2. It was suggested for the FNCA member countries to identify their specific project and prepare the work plan for 2008.
   3. Hydrogel for wound dressing has reached commercial stage in many FNCA member countries. However the problem is in the design and development of processing line at pilot scale stage. It is suggested that exchange of information regarding raw material sources and equipment manufacturer/supplier be made available to all member countries to overcome technical problem in the upgrading to semi-commercial development stage
   4. It was also proposed that radiation degraded natural polymer (alginate, chitosan, carrageenan) known already as plant growth promoter be re-branded as plant elicitor. The word ‘elicitor’ covers not only the function of oligo-saccharide as growth promoter but also the function as plant protection from fungus and insects. The re-branding would give an added value and high premium to the radiation degraded natural polymeric material.
   5. Several FNCA member countries (Bangladesh, Indonesia, Malaysia, Philippines, Thailand and Vietnam) including Pakistan and Sri Lanka agreed to further collaborate in the demonstration of the application of radiation degraded natural polymer as plant elicitor. It is suggested that Indonesia’s gamma irradiator that was established under the previous RCA/UNDP Industrial program be used for the irradiation of liquid natural polymer. The oligo-saccharides will then be distributed to other member countries for field trial. Dr. Machi will take charge of communicating this matter with the Indonesian authority. For the above purpose, it is suggested that Japan will arrange expert mission to Indonesia to assist in the irradiation of natural polymer.
   6. Malaysia will also irradiate chitosan in liquid state using the available gamma irradiator and electron beam facility at Nuclear Malaysia. The irradiated natural polymer will be used for field testing of plant elicitor. Possible collaboration with private sector and Vietnam is currently being discussed.
   7. Natural polymer based super water absorbent hydrogels have shown to have good potentials in the agricultural field. It is suggested that further work be carried out collectively within FNCA and RCA member countries for its development. Vietnam offered to provide samples of super water absorbent to other member countries for field trial upon request.
   8. Issue regarding intellectual property right such as patent should be discussed at high level committee of FNCA.
   9. IAEA / RCA workshop in relation to radiation processing of natural polymer is expected to be held in April 2008.

The participants expressed their sincere gratitude to the organizers and the host institute for a well-organized workshop and for their hospitality.