A drug delivery method for effective drug application is disclosed in this invention. In this method, a micro-carrier delivers an encapsulated, desired drug directly to targeted sites without significant interactions with other components in the biological system in the pathway. In one embodiment, a micro-carrier containing encapsulated drug is first delivered to the general area for treatment. It then scans the area and selectively attaches itself the cell site or organ location to be treated. Finally, the desired drug contained in the micro-carrier is released to the attached cell or organ. In another embodiment, a micro-device is first used to process the general area to be treated to enhance differentiation in properties (such as surface charge) between healthy cells and unhealthy cells (such as cancer cells). Drug encapsulated in the micro-carrier is next applied to preferentially attach onto the targeted sites (such as cancer cell sites) to be treated. Finally, drug is released from the micro-carrier onto the sites to be treated. Such micro-carrier preferably contains multiple functions comprised of at least two functions from the group of sensing, analyzing, logic processing, surface treatment, position detection, motion, injecting, delivering, cutting functions, removing functions, biodegradation and disintegration.
