CAJ | 학술논문

合成了以壳聚糖( CS)为主链、聚( L-谷氨酸)( PLGA)为侧链的接枝型聚两性电解质 CS-g-PLGA (CGA)，表征了其结构与组成，探讨了 pH 值、离子强度和离子种类等对 CGA 水溶液性质的影响。研究发现，随着溶液离子强度的增大， CGA 的等电点(IEP)移向高 pH 值；离子水化半径越大，对 CGA 分子中相反电荷的屏蔽作用越弱，对 IEP 的影响越小； CGA 中氨基和羧基相对含量越接近，对溶液离子强度的变化越敏感。此外， CGA 具有显著的 pH 响应性，在酸性及碱性溶液中分别形成结构相反的聚集体。在 CS 主链氨基含量相近的条件下，聚集体的稳定性随 PLGA 链长的增加而提高。酸性溶液中聚集体粒径取决于 CS 主链的电荷数；碱性溶液中 PLGA 侧链越长则平均粒径越大。
합성료이각취당( CS)위주련、취( L-곡안산)( PLGA)위측련적접지형취량성전해질 CS-g-PLGA (CGA)，표정료기결구여조성，탐토료 pH 치、리자강도화리자충류등대 CGA 수용액성질적영향。연구발현，수착용액리자강도적증대， CGA 적등전점(IEP)이향고 pH 치；리자수화반경월대，대 CGA 분자중상반전하적병폐작용월약，대 IEP 적영향월소； CGA 중안기화최기상대함량월접근，대용액리자강도적변화월민감。차외， CGA 구유현저적 pH 향응성，재산성급감성용액중분별형성결구상반적취집체。재 CS 주련안기함량상근적조건하，취집체적은정성수 PLGA 련장적증가이제고。산성용액중취집체립경취결우 CS 주련적전하수；감성용액중 PLGA 측련월장칙평균립경월대。
The graft polyampholytes containing a chitosan backbone and poly( L-glutamic acid) branches, i. e. CS-g-PLGA(CGA), with different compositions were synthesized. The molecular architecture and the composition of CGA were characterized. The influences of environmental conditions, such as pH value, ionic strength and ionic types, on the aqueous solution properties of CGAs were investigated. The results show that the isoelectric point(IEP) of CGA shifts to higher pH values with increasing the ionic strength. The larger the ion hydration radius is, the less it influences the IEP. The CGA with approximative amino and carboxyl con-tents is more sensitive to the variation of ionic strength. Moreover, CGAs exhibit notable pH responsibility to form reversible aggregates in acidic and alkaline solutions, respectively. The stability of the aggregates is found to be improved by increasing the length of PLGA branches for CGAs with similar amino content. The hydrody-namic radii of the aggregates depend on the charge density on CS backbone in acidic solutions and increase with increasing PLGA length in alkaline solutions.