Macklis J D, Quattrochi J J
Department of Neurology, Harvard Medical School, Children's Hospital, Boston, MA 02115.
Neuroreport. 1991 May;2(5):247-50. doi: 10.1097/00001756-199105000-00008.
Mapping neuronal populations that induce behavioral state changes after pharmacological activation requires discrete localization of drug injection sites, and is limited by widespread diffusion of molecular drugs. Nanospheres with diameters of 50-100 nm can reduce diffusion significantly because of their relatively large sizes. The cholinergic agonist carbachol was radiolabeled with methyl14C and incorporated within a latex nanosphere delivery system (LNDS). We quantitatively compared diffusion of 14C-carbachol within these nanospheres with that of free 14C-carbachol, demonstrating approximately ten-fold reduced radial diffusion by nanospheres 10 min to 24 h post-injection; approximately 90% of injected radioactivity was restricted to regions within approximately 100-150 microns and 1400-1500 microns respectively. Thus, incorporation of active agents such as drugs within nanospheres dramatically increases the precision of their delivery in-vivo (here about 1,000-fold by volume).
绘制药理学激活后诱导行为状态变化的神经元群体，需要药物注射部位的离散定位，并且受到分子药物广泛扩散的限制。直径为50-100纳米的纳米球由于其相对较大的尺寸，可以显著减少扩散。胆碱能激动剂卡巴胆碱用甲基14C进行放射性标记，并掺入乳胶纳米球递送系统（LNDS）中。我们定量比较了14C-卡巴胆碱在这些纳米球内的扩散与游离14C-卡巴胆碱的扩散，结果表明，注射后10分钟至24小时，纳米球使径向扩散降低了约10倍；分别约90%的注射放射性活度限制在约100-150微米和1400-1500微米范围内的区域。因此，将药物等活性剂掺入纳米球中可显著提高其体内递送的精度（此处按体积计算约为1000倍）。
