Shirkhanzadeh M
Department of Mechanical and Materials Engineering, Queen's University, Nicol Hall, 60 Union Street, Kingston, Ontario, K7L 3N6, Canada.
J Mater Sci Mater Med. 2005 Jan;16(1):37-45. doi: 10.1007/s10856-005-6444-2.
Trehalose (alpha-D-glucopyranosyl-alpha-D-glucopyranoside) is recognized as a promising fast-dissolving solid reservoir capable of stabilizing the native structure of proteins and suitable for loading with a wide variety of bioactive substances. Currently, there is a growing interest in developing cost-effective methods for immobilizing solid trehalose on arrays of microneedles for delivering protein-based and DNA-based vaccine to the epidermis. In the present work, micro-porous calcium phosphate coatings were used to provide a biocompatible interface with a large surface area for the effective immobilization of trehalose on microneedles. Calcium phosphate coatings with varying degrees of porosity were electrochemically synthesized on the tips of stainless steel acupuncture needles and loaded with solid trehalose. Skin experiments were designed to determine the ability of micro-porous calcium phosphate coatings to deliver solid trehalose into epidermis without breaking during insertion. The mechanical performance of the coatings was assessed by inserting the tips of the coated needles into human skin to an average depth of 100-300 microm and then removing them for analysis by scanning electron microscopy. Microporous calcium phosphate coatings loaded with trehalose effectively breached the stratum corneum and allowed direct access to the epidermis without breaking and without stimulating nerves in deeper tissues.
海藻糖（α-D-吡喃葡萄糖基-α-D-吡喃葡萄糖苷）被认为是一种很有前景的速溶固体载体，能够稳定蛋白质的天然结构，适用于负载多种生物活性物质。目前，人们越来越关注开发经济有效的方法，将固体海藻糖固定在微针阵列上，以便将基于蛋白质和基于DNA的疫苗递送至表皮。在本研究中，微孔磷酸钙涂层被用于提供一个具有大表面积的生物相容性界面，以便将海藻糖有效地固定在微针上。在不锈钢针灸针的针尖上通过电化学合成制备了具有不同孔隙率的磷酸钙涂层，并负载了固体海藻糖。设计皮肤实验以确定微孔磷酸钙涂层在插入过程中不折断的情况下将固体海藻糖递送至表皮的能力。通过将涂覆针的针尖插入人体皮肤至平均深度100 - 300微米，然后取出进行扫描电子显微镜分析来评估涂层的机械性能。负载海藻糖的微孔磷酸钙涂层有效地穿透了角质层，能够直接进入表皮，且不会折断，也不会刺激更深层组织中的神经。
