Rekha M R, Sharma Chandra P
Division of Biosurface Technology, Biomedical Technology Wing Sree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, Kerala, India.
J Control Release. 2009 Apr 17;135(2):144-51. doi: 10.1016/j.jconrel.2009.01.011.
In this work a novel chitosan derivative, lauryl succinyl chitosan (LSC) was developed for the purpose of evaluating its applications towards oral peptide delivery system. Nano/microparticles were developed from this derivative by sodium tripolyphosphate (TPP) cross linking. Human insulin was used as the model protein drug and the release kinetics was studied at gastrointestinal pH. The presence of succinyl carboxyl groups had inhibitory effect on the release kinetics of insulin at pH 1.2 minimizing up to about 8.5+/-0.45% in two hours. Results showed that the presence of hydrophobic moieties controlled the release of the loaded insulin from the particles at intestinal pH. The particles were negatively charged with size ranging from 315 nm to 1.090 microm. The mucoadhesive capacity was established ex vivo using the jejunum of rat intestine. Confocal microscopy studies proved the tight junction permeability in Caco 2 cells and in vivo uptake of the FITC-insulin from loaded nanoparticles by the rat intestinal epithelium. The results demonstrated that the modified chitosan with both hydrophilic (succinyl) and hydrophobic (lauryl) moieties had improved the release characteristics, mucoadhesivity as well as the permeability of the insulin compared to the native chitosan particles. The LSC2 particles were capable of reducing blood glucose levels in diabetic rats for the duration of about 6 h. This indicated that this novel derivative could be a promising candidate for oral peptide delivery.
在本研究中,为了评估其在口服肽递送系统中的应用,开发了一种新型壳聚糖衍生物——月桂基琥珀酰壳聚糖(LSC)。通过三聚磷酸钠(TPP)交联由该衍生物制备纳米/微粒。使用人胰岛素作为模型蛋白药物,并在胃肠道pH值下研究其释放动力学。琥珀酰羧基的存在对pH 1.2时胰岛素的释放动力学具有抑制作用,在两小时内释放量最小化至约8.5±0.45%。结果表明,疏水基团的存在控制了肠道pH值下负载胰岛素从颗粒中的释放。颗粒带负电荷,尺寸范围为315 nm至1.090μm。使用大鼠空肠进行体外实验确定其粘膜粘附能力。共聚焦显微镜研究证明了Caco 2细胞中的紧密连接通透性以及大鼠肠上皮对负载纳米颗粒中FITC - 胰岛素的体内摄取。结果表明,与天然壳聚糖颗粒相比,具有亲水性(琥珀酰)和疏水性(月桂基)基团的改性壳聚糖改善了胰岛素的释放特性、粘膜粘附性以及通透性。LSC2颗粒能够在约6小时内降低糖尿病大鼠的血糖水平。这表明这种新型衍生物可能是口服肽递送的有前途的候选物。