Preparation and Characterization of 6-Carboxychitosan

Zhou, Yongguo; Yang, Yuedong; Wang, Dongjun; Liu, Xiaomin

doi:10.1246/cl.2003.682

Cited by 9 publications

(3 citation statements)

References 5 publications

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“…The readers interested in various nanodimensional and nanocrystalline ion-substituted calcium orthophosphates are referred to the original publications. Furthermore, details on calcium orthophosphate-based nanodimensional biocomposites or nanodimensional calcium orthophosphate-based biocomposites [86][87][88][89][90][91][92][93][94][95][96][97][98][99][100][101][102][103][104] are available in Refs. [105,106].…”

Section: Introductionmentioning

confidence: 99%

Nanodimensional and Nanocrystalline Calcium Orthophosphates

Dorozhkin¹

2012

AJBE

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Nano-sized particles and crystals play an important role in the formation of calcified tissues of various animals. For example, nano-sized and nanocrystalline calcium orthophosphates in the form of apatites of biological origin represent the basic inorganic building blocks of bones and teeth of mammals. Namely, according the recent developments in biomineralization, tens to hundreds nanodimensional crystals of a biological apatite are self-assembled into these complex structures. This process occurs under a strict control by bioorganic matrixes. Furthermore, both a greater viability and a better proliferation of various types of cells have been detected on smaller crystals of calcium orthophosphates. Thus, the nano-sized and nanocrystalline forms of calcium orthophosphates have a great potential to revolutionize the hard tissue-engineering field, starting from bone repair and augmentation to controlled drug delivery systems. This review reports on current state of the art and recent developments on the subject, starting from synthesis and characterization to biomedical and clinical applications. Furthermore, the review also discusses possible directions for future research and development.

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Section: Introductionmentioning

confidence: 99%

Nanodimensional and Nanocrystalline Calcium Orthophosphates

Dorozhkin¹

2012

AJBE

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“…The hydromethyl group of the 2-amino-2-deoxy-Dglucose unit in chitosan could be selectively oxidized to the carboxyl group with NO 2 gas to form 6-carboxy-chitosan 8 and water. When the film was exposed to NO 2 gas some time later, the water produced during the oxidation process on the film surface could condense to tiny water drops to react with NO 2 gas to form nitric acid, and the nitric acid could induce a chitosan degradation reaction.…”

Section: Ftir Spectramentioning

confidence: 99%

“…Chandy and Rao 7 found that the chitosan, crosslinked with heparin using glutaraldehyde as a crosslinking agent, has good blood compatibility. Our previous paper 8 reported that the hydromethyl group of 2-amino-2-deoxy-D-glucose unit in chitosan could be oxidized selectively to the carboxyl group with NO 2 gas to form 6-carboxy-chitosan, and that 6-carboxychitosan was expected to have a improvement in blood compatibility. However, our preliminary studies indicated that both polysulfate chitosan derivatives and 6-carboxy-chitosan have lower intrinsic viscosity and poor ability to form fibers or membranes.…”

Section: Introductionmentioning

confidence: 99%

Blood compatibility and mechanical properties of oxidized‐chitosan films

Yang

Zhou

Chuo

et al. 2007

J of Applied Polymer Sci

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By dipping chitosan films into saturated NO 2 -glacial acetic acid solution, the hydromethyl groups on the film surface could be oxidized to carboxyl groups and the blood compatibility of the films improved. Fourier transform infrared (FTIR) spectra indicated the presence of many À ÀCOOH and À ÀCOO À groups on the modified membrane surface. Scanning electron microscopy (SEM) showed that the surface of the modified membrane was rough, as compared with the chitosan film, which possessed a smooth surface. In the oxidation process, with increased dipping time of the films in saturated NO 2 -glacial acetic acid solution, the tensile strength of the films decreased slowly initially, and rapidly 10 h later. The swelling ratio of the modified chitosan film increased obvious noticeably as the degree of oxidation of the film increased. All antithrombosis and hemolysis tests and blood cell morphology observation with SEM revealed that the blood compatibility of modified chitosan membranes is superior to that of chitosan films.

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