Fight Against Angiogenesis-Related Blindness Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul 110-744, Republic of Korea; Department of Biomedical Sciences, Seoul National University Graduate School, Seoul 110-744, Republic of Korea.
Department of Mechanical Engineering, Yonsei University, Seoul 120-749, Republic of Korea.
J Control Release. 2015 Jul 10;209:272-9. doi: 10.1016/j.jconrel.2015.04.041. Epub 2015 Apr 30.
It has been challenging for microneedles to deliver drugs effectively to thin tissues with little background support such as the cornea. Herein, we designed a microneedle pen system, a single microneedle with a spring-loaded microneedle applicator to provide impact insertion. To firmly attach solid microneedles with 140 μm in height at the end of macro-scale applicators, a transfer molding process was employed. The fabricated microneedle pens were then applied to mouse corneas. The microneedle pens successfully delivered rhodamine dye deep enough to reach the stromal layer of the cornea with small entry only about 1000 μm(2). When compared with syringes or 30 G needle tips, microneedle pens could achieve more localized and minimally invasive delivery without any chances of perforation. To investigate the efficacy of microneedle pens as a way of drug delivery, sunitinib malate proven to inhibit in vitro angiogenesis, was delivered to suture-induced angiogenesis model. When compared with delivery by a 30 G needle tip dipped with sunitinib malate, only delivery by microneedle pens could effectively inhibit corneal neovascularization in vivo. Microneedle pens could effectively deliver drugs to thin tissues without impairing merits of using microneedles: localized and minimally invasive delivery.
对于微针来说，向缺乏背景支撑的组织（如角膜）有效输送药物一直具有挑战性。在此，我们设计了一种微针笔系统，该系统由一个带有弹簧加载微针给药器的单个微针组成，可提供冲击插入。为了将 140μm 高的实心微针牢固地固定在宏观规模给药器的末端，采用了转移模塑工艺。然后将制造的微针笔应用于小鼠角膜。微针笔成功地将罗丹明染料输送到角膜的基质层，入口仅约 1000μm（2）。与注射器或 30G 针头相比，微针笔可以实现更局部和微创的输送，而不会有任何穿孔的风险。为了研究微针笔作为一种药物输送方式的效果，马来酸舒尼替尼已被证明可以抑制体外血管生成，将其输送到缝线诱导的血管生成模型中。与用蘸有马来酸舒尼替尼的 30G 针头输送相比，只有微针笔才能有效地抑制体内角膜新生血管形成。微针笔可以将药物有效递送到薄组织中，而不会损害使用微针的优点：局部和微创输送。
