Fabrication of microneedles for skin interstitial fluid extraction for allergy testing

对于经皮给药、皮肤液体和血液提取，传统的不锈钢针给患者带来疼痛，并且难以在现场护理测试领域与其他医疗设备集成。针对这些限制的一种解决方案是微针阵列，因为其最小的侵入面积/深度引起较少的疼痛，并且能够与其他微型设备集成。此外，迄今为止，还没有关于微型针头感染病例的报告。这种微针可以是实心或空心的，长度约为500-1200微米，外径不超过300微米。支持公司ExVivo Labs正在开创用于筛查过敏症的新型护理点医疗技术。过敏是一个普遍的问题，影响着加拿大和美国约6000万人。据估计，在美国治疗过敏性鼻炎的医疗支出几乎从2000年的61亿美元（以2005年美元计）翻了一番，达到2005年的112亿美元，这对社会来说是一个显著且不断增加的经济负担。ExVivo实验室的目标是减少急诊就诊次数、数百万人的缺勤率和过敏症的总成本。它的过敏测试贴片是基于 ** 提取使用微针阵列的疾病指示生物标志物，如免疫球蛋白-E（IgE），介导I型超敏反应，称为过敏。在这个CRD项目中，我们的目标是制造中空硅和聚合物，面外和面内，微针阵列使用MEMS微加工技术，特别是光刻和深硅蚀刻。随后将通过各向同性干法和/或湿法蚀刻将制造的针锐化至10微米以下，用于无痛插入皮肤。

For transdermal drug delivery, skin fluid and blood extraction, the conventional stainless steel needle causes pain to the patients and is hard to be integrated with other medical devices at point-of-care-test fields. One solution to those limitations is micro-needle array because of its minimal invasive area/depth causing less pain, and ability to be integrated with other micro-devices. Moreover, no cases of infection by micro-needles have been reported so far. Such micro-needles can be solid or hollow with an approximate length of 500-1200 um and an external diameter of not more than 300 µm.**The supporting company ExVivo Labs is pioneering novel point-of-care medical technologies for screening allergies. Allergies are a pervasive problem affecting approximately 60 million people in Canada and the United States. It is estimated that medical expenditures to treat allergic rhinitis in the U.S. almost doubled from $6.1 billion in 2000 (in 2005 dollars) to $11.2 billion in 2005, representing a significant and increasing economic burden to society. ExVivo Labs targets to reduce the number of emergency visits to the hospital, workplace absenteeism for millions of people, and overall cost of allergies. Its allergy test patches are based on**extraction using micro-needle array of disease-indicating biomarkers, such as immunoglobulin-E (IgE), which mediates type I hypersensitivity reactions, known as allergies. In this CRD project, we aim to fabricate hollow silicon and polymer, out-of-plane and in-plane, micro-needle array using MEMS microfabrication techniques, notably photolithography and deep silicon etching. The fabricated needles will be subsequently sharpened to under 10 micrometers by isotropic dry and/or wet etching, for painless insertion into skin.