Abstract: The present invention relates to a positive electrode active material and a lithium secondary battery using a positive electrode containing the positive electrode active material. More particularly, the present invention relates to a positive electrode active material that is able to solve a problem of increased resistance according to an increase in Ni content by forming a charge transport channel in a lithium composite oxide and a lithium secondary battery using a positive electrode containing the positive electrode active material.

Abstract: The present invention relates to a composition for anti-green algae containing water-soluble free amine chitosan having the anti-algae activity against water-bloom forming algae as an active ingredient and a method for preparing the same. Particularly, the water-soluble free amine chitosan of the present invention can kill directly water-bloom forming algae, suggesting that it has excellent anti-green algae activity to inhibit water-bloom, and is non-toxic to freshwater organism cells. Therefore, the composition for anti-green algae containing the said water-soluble free amine chitosan as an active ingredient can be efficiently used as a safe anti-green algae composition applicable in the freshwater ecosystem including solidified dam, reservoir, lake, golf course water hazard, pond, freshwater fish farm, and fishing spot.

Abstract: The present invention relates to a water soluble chitosan nanoparticle (WSC-NP) for delivering an anticancer agent and a preparing method thereof, more precisely, a water soluble chitosan nanoparticle for delivering an anticancer agent which has function of targeting on a wanted area by introducing a functional group in the location of highly reactive amine group and becomes an excellent gene carrier with the use of water soluble chitosan since the water soluble chitosan itself can combined with DNA having a negative electric charge(?) owing to the very strong positive electric charge(+) of its amine group, and a preparing method thereof. Therefore, a water-soluble chitosan nanoparticle for delivering an anticancer agent of the present invention can effectively envelope paclitaxel by introducing hydrophilic and hydrophobic groups in the position of highly reactive amine group of the water-soluble chitosan.

Abstract: Disclosed are low-molecular weight, water-soluble chitosan nanoparticles with folic acid conjugated thereto as a target ligand and a preparation method thereof. The nanoparticles can be simply prepared since the strong reactivity of the chitosan allows folic acid to be readily introduced thereinto. Also, the folic acid-conjugated, low-molecular weight, water-soluble chitosan nanoparticles can be useful as gene carriers because they are of low or zero-toxicity, have sizes suitable for use as gene carriers, can readily form complexes with DNA, allow high gene expression rates, and are excellent in targeting tumor cells which are rich in folic acid receptors.

Abstract: A method for the preparation of water-soluble chitosan with high purity and biological activity includes steps of: reacting chitosan oligo sugar acid salt, covalently bonded to an organic or inorganic acid, with trialkylamine in phosphate buffered saline followed by addition of an organic solvent to remove acid salt at C-2 position; adding the thus obtained reaction mixture to an inorganic acid to remove trialkylamine salt at C-6 position; and passing the thus obtained free amine chitosan through an activated carbon/ion exchange resin. The free amine chitosan is water-soluble and has a high bioavailability for application to the medicine and food industries.

Abstract: The present invention relates to a water soluble chitosan nanoparticle (WSC-NP) for delivering an anticancer agent and a preparing method thereof, more precisely, a water soluble chitosan nanoparticle for delivering an anticancer agent which has function of targeting on a wanted area by introducing a functional group in the location of highly reactive amine group and becomes an excellent gene carrier with the use of water soluble chitosan since the water soluble chitosan itself can combined with DNA having a negative electric charge(?) owing to the very strong positive electric charge(+) of its amine group, and a preparing method thereof. Therefore, a water-soluble chitosan nanoparticle for delivering an anticancer agent of the present invention can effectively envelope paclitaxel by introducing hydrophilic and hydrophobic groups in the position of highly reactive amine group of the water-soluble chitosan.

Abstract: A method for the preparation of water-soluble chitosan with high purity and biological activity includes steps of: reacting chitosan oligo sugar acid salt, covalently bonded to an organic or inorganic acid, with trialkylamine in phosphate buffered saline followed by addition of an organic solvent to remove acid salt at C-2 position; adding the thus obtained reaction mixture to an inorganic acid to remove trialkylamine salt at C-6 position; and passing the thus obtained free amine chitosan through an activated carbon/ion exchange resin. The free amine chitosan is water-soluble and has a high bioavailability for application to the medicine and food industries.