对成分相同的药物来说，线形纳米颗粒药物比球形状药物在血液里循环的时间更长，新研究成果发表在4月号的《自然—纳米技术》上，这表明在癌症治疗的药物传输器设计中，形状的考虑很重要。
Dennis Discher和同事发现，柔软的丝状聚合体在小鼠和老鼠体内循环的时间可长达一周，而球形的纳米颗粒或其他像碳纳米管结构的颗粒在体内循环的时间只有几个小时。循环时间的长短取决于丝状部分如何随液体流动，以及它们与细胞间的相互作用。
部分英文原文：
Nature Nanotechnology 2, 249 - 255 (2007)
Published online: 25 March 2007 | doi:10.1038/nnano.2007.70
Subject Categories: Nanobiotechnology | Nanomedicine | Nanoparticles
Shape effects of filaments versus spherical particles in flow and drug delivery
Yan Geng1,3, Paul Dalhaimer1,3, Shenshen Cai1, Richard Tsai1, Manorama Tewari1, Tamara Minko2 & Dennis E. Discher1
Abstract
Interaction of spherical particles with cells and within animals has been studied extensively, but the effects of shape have received little attention. Here we use highly stable, polymer micelle assemblies known as filomicelles to compare the transport and trafficking of flexible filaments with spheres of similar chemistry. In rodents, filomicelles persisted in the circulation up to one week after intravenous injection. This is about ten times longer than their spherical counterparts and is more persistent than any known synthetic nanoparticle. Under fluid flow conditions, spheres and short filomicelles are taken up by cells more readily than longer filaments because the latter are extended by the flow. Preliminary results further demonstrate that filomicelles can effectively deliver the anticancer drug paclitaxel and shrink human-derived tumours in mice. Although these findings show that long-circulating vehicles need not be nanospheres, they also lend insight into possible shape effects of natural filamentous viruses.
NanoBioPolymers and Molecular & Cell Biophysics Lab, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
Pharmaceutics, Rutgers University, Piscataway, New Jersey 08854, USA These authors contributed equally to this work.
