Smart polymeric carriers for drug delivery oxidation-responsive nanocarriers

4 Smart polymeric carriers for drug delivery oxidation-responsive nanocarriers 

For drug delivery applications, cross-linking through disulfides can be useful for increasing the stability of polymeric micelles or other types of nanoparticles in vivo. Wang et al. (2011) synthesized disulfide bridged block copolymer of PCL and poly(ethylethylene phosphate) (PCL-SS-PEEP), which self-assembled into 90 nm micellar structures. When these micelles were loaded with DOX, more drug accumulation and retention was observed in MDR cells compared to normal block copolymers, and rapid 

Redox- Hydrophiiic domain responsive with high cett aiiinity tinkage 

4 Schematic illustration of (a) the chemical structure of disulfide-bridged PCL-SS-PEEP block copolymer and (b) of the activity of redox-responsive nanocarriers upon cellular uptake and release in the reductive environment of the cytosol. 

Micelles based on thiolated pluronics have also been developed, with disulfide cross-linked cores,loaded with paclitaxel (Abdullah Al et a/.,2011). These demonstrate accumulation in the cytoplasm and increased cytotoxicity when incubated with A549 cells. 

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