Journal of Chemical Engineering & Process Technology
Open Access
ISSN: 2157-7048
ISSN: 2157-7048
Maiko K. Okajima*, Saranyoo Sornkamnerd, Kittima Amornwachirabodee and Tatsuo Kaneko*
Japan Advanced Institute of Science and Technology, Japan
Scientific Tracks Abstracts: J Chem Eng Process Technol
Hydrogels are composed of three-dimensional network structures of synthetic and/or natural polymers which are able to absorb and to retain significant amount of water. The hydrogels have been extensively used in various biomedical applications such as drug delivery, cell carriers and/or entrapment, wound management, and tissue engineering. Sacran which is extracted from Aphanothece sacrum biomaterials is a cyanobacterial polysaccharide with a very high molecular weight of 29 Mg/mol, containing 11 % of sulfate group, 22 % of carboxyl group. Sacran has a function of liquid crystals in thin aqueous solution and a super-absorbent property to induce an anti-inflammatory activity2. Here we found that the physical hydrogel of sacran can be prepared from the film made by water-casting. Practically sacran solution with a concentration of 0.5 % was dried at 60 degC for 12 h to create the thin film with in-plane orientation, and the film was immersed into pure water to form anisotropic hydrogels having a layer structure. This phenomenon was observed only in high-molecular weight sacran but not in other polysaccharides. Furthermore, it was found that the swollen degree of the gels was controlled by the preheating temperature ranging 70-140 degC, to adjust the swollen degree of the hydrogels from 10 to 400 times. The following properties of the hydrogels were further evaluated, water content, swelling ratio in water, gel strength, and stimuli responsiveness, in terms of anisotropy. The mechanical properties and network structures of hydrogels were also studied, clarifying that porous hydrogels, even those with a high quantity of pores were tough owing to the pores orienting along the layer direction like tunnels. The authors gratefully acknowledges Grant-in-Aid supports from A-step, (AS2915173U) of JST, Japan and from collaborative research fund of GSM, Japan. grant-in-aid for Challenging Exploratory Research of MEXT (16K14077). Figure. Hydrogels prepared by in-situ gelation of films thermally-cross-linked through annealing at various temperatures (left). SEM of side view of freeze-dried gel films (right) Recent Publications 1. Amornwachirabodee K, Okajima KM, Kaneko T (2015) Uniaxial Swelling in LC Hydrogels Formed by Two-step Crosslinking, Macromolecules, 48: 8615��?8621. 2. Okajima KM, Mishima R, Amornwachirabodee K, Okeyoshi K, Kaneko T (2015) Anisotropic Swelling in Hydrogels Formed by Cooperatively Aligned Megamolecules, RSC Adv. 5: 86723-86729. 3. Ngatu NR, Tanaka M, Okajima KM, Yokogawa M, Ikeda M, Inoue M, Watanabe H, Kanbara S, Nojima S, Kaneko T, Suganuma N (2016) Anti-allergic effects and immunomodulatory activity of sacran, a bioactive compound from river alga aphanothece sacrum, Evidence-based Med.Public Health, 2: e1438. 4. Zhao Y, Hien KTT, Mizutani G, Rutt HN, Amornwachirabodee K, Okajima KM, Kaneko T (2017) Optical Second- Harmonic Images of Sacran Megamolecules Aggregates, J. Opt. Soc. Amer. A, 34: 146-152. 5. Sornkamnerd S, Okajima KM, Matsumura K, Kaneko T (2018) Surface-selective control of cell-orientation on cyanobacterial liquid crystalline gels, ACS Omega, in press.
Maiko Kaneko Okajima is the Postdoctoral research fellow of the School of Materials Science at JAIST, Nomi, Japan, and R&D manager of Green Science Materials Inc. Japan. She has approximately 65 publications. She has been involved in scientific and industry-academic collaborative projects in the fields of Cyanobacterial biology, Polysaccharides, Biomedical design etc. Additionally she has engaged in establishment of Start-up Company on cyanobacterial polysaccharides and their applications as biomedical and cosmetic ingredients.