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Chulalongkorn University

Chitosan

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Role Of Aluminum Monostearate On Heat Treated-Chitosan Sponges Properties, K. Yodkhum, T. Phaechamud Dec 2012

Role Of Aluminum Monostearate On Heat Treated-Chitosan Sponges Properties, K. Yodkhum, T. Phaechamud

Journal of Metals, Materials and Minerals

Heat treatment can be employed to modify properties such as biocompatibility and degradation rate of chitosan-based materials. However, heat treatment generally has effect on worsening of physical properties of the biomaterials. Our previous study indicated that fatty additive; aluminum monostearate (Alst), could improve thermal stability of chitosan sponges. Aim of this study is to investigate an effect of amount of Alst on physicochemical properties of chitosan sponges treated by different heat treatment methods. Two methods of heat treatment including moist heat (autoclave at 121°C, 15 psi for 5 minutes) and dry heat (vacuum heat at 110°C for 24 hours) were …


Preparation And Characterization Of Particles From Chitosan With Different Molecular Weights And Their Trimethyl Chitosan Derivatives For Nasal Immunization, W Boonyo, H E. Junginger, N Waranuch, A Polnok, T Pitaksuteepong Dec 2008

Preparation And Characterization Of Particles From Chitosan With Different Molecular Weights And Their Trimethyl Chitosan Derivatives For Nasal Immunization, W Boonyo, H E. Junginger, N Waranuch, A Polnok, T Pitaksuteepong

Journal of Metals, Materials and Minerals

According to previous studies, molecular weights (MW) of chitosan presented an influence on the level of immune response to model antigen when administering with chitosan through nasal route. Moreover, trimethyl chitosan (TMC) with a degree of quaternization (DQ) of 40%, chitosan derivatives, was also shown to be the most potent nasal OVA delivery platforms compared to TMC with DQ of 20% and 60% in mice model. The aims of this study were to prepare particles from chitosan with difference MW and their TMC derivatives (DQ = 40%) and to characterize size, zeta potential, loading efficiency and release profile in order …


Preparation Of N-Acetyl-D-Glucosamine Using Enzyme From Aspergillus Sp., P Setthakaset, R Pichyangkura, A Ajavakom, M Sukwattanasinitt Dec 2008

Preparation Of N-Acetyl-D-Glucosamine Using Enzyme From Aspergillus Sp., P Setthakaset, R Pichyangkura, A Ajavakom, M Sukwattanasinitt

Journal of Metals, Materials and Minerals

N-acetyl-D-glucosamine (GlcNAc) is one of the basic constituents of mammal cartilage, which is known to help repair deteriorating cartilage and relieve pain and inflammation in osteoarthritis patients. The preparation of GlcNAc from squid pen β-chitin by using Aspergillus sp. chitinase in enzymatic hydrolysis is studied. The cultivation of the fungus in colloidal chitin minimum media at pH 3.5 and 40°C for 5 days gives the highest chitinolytic activity of 3.1 U/mL. The crude enzyme obtained from the the cultivation is used in the hydrolysis of milled squid pen β-chitin (50μm) at pH 4 (acetic acid 2M) and 45°C using 22 …


Surface Modification Of Bricks By Chitosan Coatings, S Nilpairach, S T. Dubas Jul 2008

Surface Modification Of Bricks By Chitosan Coatings, S Nilpairach, S T. Dubas

Journal of Metals, Materials and Minerals

Bricks were successfully modified by application of a chitosan coating in order to provide their surface with a water repellant character. The chitosan coating was prepared by depositing solutions of variable chitosan concentration (1% or 2.5% w/w) onto the brick surface and let to dry under ambient condition. In order to improve the water repellant property, the films were cross-linked with a 1% solution of sodium citrate, sodium sulfate or sodium tri - polyphosphate. The effect of the chitosan concentration on the morphology of the coating at the brick surface was observed by scanning electron microscope (SEM). It was found …


Improved L-929 Cell Growth From Self Assembled Pdadmac/Gelatin Thin Films, P Kittitheeranun, P Potiyaraj, T Bunaprasert, N Sanchavanakit, S T. Dubas Jul 2008

Improved L-929 Cell Growth From Self Assembled Pdadmac/Gelatin Thin Films, P Kittitheeranun, P Potiyaraj, T Bunaprasert, N Sanchavanakit, S T. Dubas

Journal of Metals, Materials and Minerals

This article demonstrates the advantages of using PDADMAC/gelatin over chitosan/gelatin multilayer thin films to improve L-929 mouse fibroblast growth. Although chitosan-based materials are often preferred in cell culture, we put in evidence the problematic low stability and decomposition of chitosan based film under physiological pH. Two kinds of coating were assembled using either chitosan or Poly(diallyldimethylammonium chloride) (PDADMAC) as polycationic polyelectrolyte and gelatin as the anionic counterpart. The non-toxic nature of each coating was confirmed by MTT assay for cell viability and cell proliferation. Using optical microscopy, it was observed that the L-929 fibroblast spread preferentially on the PDADMAC/gelatin surface …


Development Of Flame Retardant Polyphosphoric Acid Coating Based On The Polyelectrolyte Multilayers Technique, K Srikulkit, C Iamsamai, S T. Dubas Dec 2006

Development Of Flame Retardant Polyphosphoric Acid Coating Based On The Polyelectrolyte Multilayers Technique, K Srikulkit, C Iamsamai, S T. Dubas

Journal of Metals, Materials and Minerals

Polyelectrolyte multilayer (PEM) thin films were deposited on silk by sequential deposition of Chitosan and polyphosphoric acid. This PEM composition takes advantage of synergetic effect of the phosphorus and the nitrogen to provide an efficient coating, which prevents fiber decomposition at high temperature. Prior to the PEM assembly on silk fibers, the growth of the film was initially monitored using an atomic force microscopy (AFM). Films formed on silicon wafer after 10, 20, 30, 40 and 60 layers showed somewhat linear increase, which is consistent with the PEM technique. A total thickness ranging from 10 to 107 nm for the …


Properties Of Collagen/Chitosan Scaffolds For Skin Tissue Engineering, C Tangsadthakun, S Kanokpanont, N Sanchavanakit, T Banaprasert, S Damrongsakkul Jul 2006

Properties Of Collagen/Chitosan Scaffolds For Skin Tissue Engineering, C Tangsadthakun, S Kanokpanont, N Sanchavanakit, T Banaprasert, S Damrongsakkul

Journal of Metals, Materials and Minerals

Biopolymer blends between collagen and chitosan have the potential to produce cell scaffolds with biocompatible properties. In this study, porous scaffolds were fabricated by freeze drying the solution of collagen and chitosan and crosslinked by dehydrothermal treatment (DHT). Various types of scaffolds were prepared by varying compositions of collagen and chitosan. The scaffolds were fully characterized by Fourier transform infrared (FT-IR) spectroscopy. The results proved that collagen and chitosan scaffolds in all blending compositions contained only physical but not chemical interaction in molecular level. The compressive modulus from a universal mechanical testing machine decreased with increasing the compositions of chitosan. …