Cheung Karmen, Han Tao, Das Diganta Bhusan
Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, UK.
Department of Chemical Engineering, Loughborough University, Loughborough, Leicestershire, UK
J Diabetes Sci Technol. 2014 May;8(3):444-52. doi: 10.1177/1932296813519720. Epub 2014 Jan 21.
Many experiments conducted in the literature have investigated the effect of microneedles (MNs) on insulin permeation across skin. There are also a number of articles that deal with the effect of MN insertion force in skin. However, there is little known on quantifying the relationship between the effect of MN insertion force and the amount of insulin permeated for given MNs. This issue is addressed in this article. MNs of 1100 µm and 1400 µm are used to conduct in vitro permeability experiments on porcine skin, using insulin. Histological images of MN treated skin are obtained from a microtome and the viscoelastic properties of the skin sample are measured using a rheometer. An in-house insertion force device is utilized that can reproducibly apply a specified force on MNs for a set period of time using compressed air. It is deduced that when porcine skin was pretreated with an applied force of 60.5 N and 69.1 N, the resultant amount of insulin permeated was approximately 3 µg and 25 µg over a 4-hour period for the MNs used. The amount of MN force applied to porcine skin was shown to be related to the amount of insulin permeated. An increase in insertion force increase the amount of insulin permeated. It was also demonstrated that using insufficient force may have reduced or prevented the amount of insulin passing through the skin, regardless of the geometry of the MNs.
文献中进行的许多实验都研究了微针（MNs）对胰岛素透过皮肤的影响。也有一些文章探讨了MNs插入皮肤时的作用力的影响。然而，对于给定的MNs，量化MNs插入力的影响与胰岛素渗透量之间的关系却知之甚少。本文将解决这个问题。使用1100 µm和1400 µm的MNs对猪皮进行体外渗透性实验，使用胰岛素。从切片机获得MN处理过的皮肤的组织学图像，并使用流变仪测量皮肤样本的粘弹性特性。利用一种自制的插入力装置，该装置可以使用压缩空气在设定的时间段内对MNs可重复地施加指定的力。据推断，当猪皮在60.5 N和69.1 N的作用力下进行预处理时，对于所使用的MNs，在4小时内胰岛素的渗透量分别约为3 µg和25 µg。施加在猪皮上的MN力的大小与胰岛素的渗透量有关。插入力的增加会增加胰岛素的渗透量。还证明了，无论MNs的几何形状如何，使用的力不足可能会减少或阻止胰岛素透过皮肤。
