Study on β-cyclodextrin grafting with chitosan and slow release of its inclusion complex with radioactive iodine

beta -CD-2-CTS was synthesized by beta -cyclodextrin reacting with p-toluenesulfonyl chloride, then grafting with chitosan. The infrared spectra analysis and C-13 NMR confirmed that beta -cyclodextrin reacted with p-toluenesulfonyl chloride at the 2-position carbon atom in the substituted glucose unit of beta -cyclodextrin and formed beta -CD-2-OTs. In the C-13 NMR of beta -CD-2-OTs, the characteristic peak of the 2-postion carbon atom in the substituted glucose unit of beta -cyclodextrin appeared at 78.43 ppm. beta -CD-2-CTS was characterized with infrared spectra analysis and X-ray diffraction. In the infrared spectra of beta -CD-2-CTS, the characteristic peak of alpha -pyanyl vibration of beta -CD was at 848.6 cm(-1). The characteristic peak of beta -pyanyl vibration of CTS was at 894.9 cm(-1). The X-ray diffraction analysis showed that the peak at 2 theta = 20 degrees decreased greatly in beta -CD-2-CTS. The polymer inclusion complex of beta -CD-2-CTS with iodine was prepared and its inclusion ability was studied. The experimental results showed that a nice bit of iodine was included with beta -CD-2-CTS and formed a stable inclusion complex. After the subcutaneous implantation of the polymer inclusion complex of beta -CD-2-CTS with I-131(2), in rats, I-131(2) exhibited the property of slow release. I-131(2) in the blood of rats decreased slowly. I-131(2) in the blood of rats maintained approximately half of maximum for 70 days later, and maintained much higher radioactivity in the organs of rats compared to the inclusion complex of beta -CD with I-131(2) too. (C) 2001 John Wiley & Sons, Inc.