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