Controlled biodegradation rate in the body
This technology is characterized in that a pH-sensitive poly (amino acid) compound, for example, a poly(β-amino ester), poly(amido amine) or a copolymer thereof is copolymerized with a hydrophilic polyethylene glycol compound to provide a block copolymer, which is sensitive to pH variations in the body, forms micelle structures at a specific pH range and has a controlled biodegradation rate in the body.
Stable micelle structure at a specific pH range
The pH-sensitive micelle maintains a stable micelle structure at a specific pH range, for example, pH 7.2~7.4 (i.e., pH range of normal cells in the body). However, the pH-sensitive micelle structure collapses in a pH of 7.2 or lower as can be found in abnormal cells such as cancer cells. Therefore, the pH-sensitive micelle can be used as carrier for target-directed drug delivery to cancer cells.
Use of delivery of genes and drugs
The block copolymer capable of forming the above-described pH-sensitive micelles can deliver a diagnostic substance to abnormal cells, and thus can also be applied to the filed of diagnosis including diagnostic imaging.