Patent ID: 8795721

Claim:
A device for delivering a substance in situ in a body, comprising: (a) at least one permeable expandable sac having a first dimension that is expandable into a larger second dimension and having contained therein the substance to be delivered; (b) at least one expandable particle comprising a swellable material contained within the sac and capable of expanding when contacted with a fluid; (c) a carrier; (d) at least one coupling member that ties the at least one sac closed and also couples the at least one sac to the carrier; and (e) a decoupling mechanism configured and operable to disrupt the at least one coupling member in a manner that both decouples the at least one sac from the carrier, and also opens up the at least one sac in order to release the at least one expandable particle therefrom whereby when the device is positioned in situ, bodily fluid permeates the at least one sac, thereby causing the at least one expandable particle contained therein to swell and the at least one sac to expand from the first dimension to the second dimension so that the device remains in situ for a period of time sufficient to achieve the desired delivery of the substance, after which time the decoupling mechanism disrupts the at least one coupling member and thereby separates the at least one sac from the carrier and also opens up the at least one sac and releases the at least one swelled particle therefrom.