Dear all, we are working on vaccine delivery with HA microneedle patch. During this, we found that it is difficult to make the microneedle patch compeltely insert into mice skin with a spring applicator with a long time such as 10 min or more. The spring applicator is helpful, but with the removal of applicator, the microneedle patch usually leaves out from the skin. It happened even using a tap to fix the microneedle patch onto mice skin after applicator punching.

Is there any better method to insert microneedle patch into skin? We are looking forward to your reply. Your suggestion and experience will be greatly appreciated.