tailieunhanh - Study on Synthesis of chitosan nanoparticles and their application for drug carriers

In this communication, we report the synthesis of chitosan (CS, a biodegradable and biocom- patible natural polymer) [1] nanoparticles as drug carriers by ionic gelation. The method is based on ionic interactions between positively charged groups NH3 + of CS (in dilute CH3COOH solution) and negatively charged of sodium tripolyphos- phate, TPP). This mechanism was confirmed by IR analyses: the presence of the P=O and P-O groups at the frequency of 1180 cm-1 and 1250 cm-1 res- pectively for CS-TPP nanoparticles; and the shifts from 1650 cm-1 and 1595 cm-1 , corresponding to C-O and N-H stretching respec-tively in pure CS, to 1636 cm-1 and 1539 cm-1 for CS-TPP nano- particles, indicated the interaction between CS and TPP [2]. | SHORT COMMUNICATION STUDY ON SYNTHESIS OF CHITOSAN NANOPARTICLES AND THEIR APPLICATION FOR DRUG CARRIERS Received 2004 TRAN DAI LAM1 LE THI NGOC LIEN2 VU DINH HOANG1 NGUYEN NGOC THINH PHAM GIA DIEN2 1Faculty of Chemical Technology Hanoi University of Technology 2Institute of Chemistry Vietnamese Academy for Science and Technology In this communication we report the synthesis of chitosan CS a biodegradable and biocompatible natural polymer 1 nanoparticles as drug carriers by ionic gelation. The method is based on ionic interactions between positively charged groups NH3 of CS in dilute CH3COOH solution and negatively charged of sodium tripolyphosphate TPP . This mechanism was confirmed by IR analyses the presence of the P O and P-O groups at the frequency of 1180 cm-1 and 1250 cm-1 respectively for CS-TPP nanoparticles and the shifts from 1650 cm-1 and 1595 cm-1 corresponding to C-O and N-H stretching respec-tively in pure CS to 1636 cm-1 and 1539 cm-1 for CS-TPP nanoparticles indicated the interaction between CS and TpP 2 . To reach the desired particle size the dissociation degrees of CS and TPP must be controlled. These parameters in their turn depend on starting concentrations and especially on pH solutions. Hence combined pH and UV-vis measurements were carried out first for TPP and CS solutions separately and then for their mixture in order to study the nanoparticle formation at different pH. It was found that the absorbance variations of these solutions could be correlated to their different degrees of ionization depending on pH values. TEM images showed clearly that the particle size was in the range of 50 - 70 nm and its distribution was quite narrow. Afterwards the capacity of CS-TPP nanoparticles to associate with bioactive com-pounds has been demonstrated for BSA Bovine Serum Albumin as a model protein and for Artesunic acid as antimalarial artemisinin derivative. Being small in size CS microspheres have large surface to volume ratios and can be