Casadei Maria Antonietta, Matricardi Pietro, Fabrizi Giancarlo, Feeney Michelle, Paolicelli Patrizia
Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Sapienza Università di Roma, Rome, Italy.
Eur J Pharm Biopharm. 2007 Nov;67(3):682-9. doi: 10.1016/j.ejpb.2007.04.010. Epub 2007 Apr 22.
A carboxymethyl derivative of scleroglucan (Scl-CM) was synthesized and characterized through FT-IR, 1H NMR and potentiometer titration. Rheological studies allowed evidencing the effect produced by the introduction of the carboxymethyl moiety on the native polymer. The mechanical spectrum of the scleroglucan solution showed a weak gel behaviour, while the derivative one looked like a system near the gel point, that evolved to a gel state depending on the concentration. This difference could be related to conformational changes due to the introduction of the negative charges on the chains. Different concentrations of Ca2+, added to the aqueous solutions of Scl-CM, were able to deeply modify the resulting system, showing a sharp transition toward a gel like behaviour. Acyclovir was loaded into the hydrogels obtained with different amounts of polymer and salt. The release rate of the drug from these systems was strictly related to both concentrations of salt and polymer. The obtained results suggest a possible employment of these new hydrogels for topical formulations or in situ implantation.
合成了硬葡聚糖的羧甲基衍生物（Scl-CM），并通过傅里叶变换红外光谱（FT-IR）、核磁共振氢谱（1H NMR）和电位滴定法对其进行了表征。流变学研究揭示了羧甲基部分的引入对天然聚合物产生的影响。硬葡聚糖溶液的力学谱显示出较弱的凝胶行为，而衍生物的谱图则类似于接近凝胶点的体系，该体系会根据浓度演变成凝胶状态。这种差异可能与链上引入负电荷导致的构象变化有关。向Scl-CM水溶液中添加不同浓度的Ca2+能够深刻改变所得体系，呈现出向凝胶状行为的急剧转变。将阿昔洛韦负载到由不同量的聚合物和盐制备的水凝胶中。药物从这些体系中的释放速率与盐和聚合物的浓度都密切相关。所得结果表明这些新型水凝胶可能用于局部制剂或原位植入。
