Takashima Yuuki, Tsuchiya Tomohiro, Igarashi Yuko, Kanazawa Takanori, Okada Hiroaki, Urtti Arto
Pharmaceutical Technology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, Japan.
Yakugaku Zasshi. 2012;132(12):1365-70. doi: 10.1248/yakushi.12-00234-3.
Nucleic acids like siRNA and pDNA are remarkable for treatment of ophthalmic diseases in posterior segment of eye such as age-related macular degeneration (AMD). However, hydrophilic and high molecule compounds are restricted in intraocular distribution through anterior segment of the eye. In addition, the ocular tissue has a blood-retinal barrier which restricts drug delivery thorough systemic administration. Therefore the invasive intravitreal injection has been generally applied for treatment of retinal diseases. The objective in this study is to prepare nucleic acid-loaded liposomes for effective gene delivery to posterior segment of eye by non-invasive ophthalmic administration such as eye-drops. The pDNA/PEI-complex loaded liposomes were prepared using detergent removal method. The obtained liposomes were lyophilized with optimal amount of a cryoprotectant to avoid changes in physical properties and, followed by adjustment of an appropriate volume and osmotic pressure as ophthalmic solution. The liposomes show high pDNA encapsulation efficiency and good cellular uptake ability in human retinal pigment epithelial cells (ARPE-19 cells). We further demonstrate that the modification of ligand which binds to specific receptor on the RPE cells to the liposomes may improve gene delivery efficacy to the posterior segment of eye by non-invasive ocular instillation.
像小干扰RNA(siRNA)和质粒DNA(pDNA)这样的核酸在治疗眼部后段的眼科疾病如年龄相关性黄斑变性(AMD)方面表现出色。然而,亲水性高分子化合物在通过眼前段进行眼内分布时受到限制。此外,眼部组织存在血视网膜屏障,这限制了通过全身给药进行药物递送。因此,侵入性玻璃体内注射已普遍应用于视网膜疾病的治疗。本研究的目的是制备负载核酸的脂质体,通过非侵入性眼科给药(如滴眼剂)将基因有效递送至眼后段。采用去垢剂去除法制备负载pDNA/聚乙烯亚胺(PEI)复合物的脂质体。将获得的脂质体用最佳量的冷冻保护剂冻干,以避免物理性质发生变化,然后调整为合适的体积和渗透压作为眼用溶液。这些脂质体在人视网膜色素上皮细胞(ARPE - 19细胞)中显示出高pDNA包封效率和良好的细胞摄取能力。我们进一步证明,将与视网膜色素上皮(RPE)细胞上特定受体结合的配体修饰到脂质体上,可能通过非侵入性眼内滴注提高基因递送至眼后段的效率。