The present invention discloses a biocarrier for delivery of a bioactive substance near/into a target cell, comprising a bioactive substance-loaded core with a first electricity, and one or more block copolymer, each block copolymer comprising a zwitterionic block and an anchoring block with an initial electricity opposite to the first electricity, wherein the anchoring block binds to the core by electrostatic attraction, and the zwitterionic block extends outwardly to increase the biocarrier stability in mammalian blood. Additionally, the present invention also discloses a method of using the biocarrier.
