Nanoparticles built of cross-linked heterotelechelic, amphiphilic poly(dimethylsiloxane)-b-poly(ethylene oxide) diblock copolymers

Novel short chain alpha,omega-heterotelechelic amphiphilic poly(dimethylsiloxane)-b-poly(ethylene oxide) diblock copolymers (PDMS-PEO) with total molecular weights below 10 000 g/mol are synthesized, characterized, and used as basic constituent parts for functionalized nanoparticles. The self-assembly of the amphiphilic diblock copolymer in water as a solvent selective for the PEO block leads to the formation of spherical and cylindrical micellar structures with diameters between 10 and 25 nm. The core of the micelles is built of the hydrophobic PDMS chains, whereas the corona is set up by the hydrophilic PEO blocks. By using a,w-heterotelechelic diblock copolymers, it is possible to fix the core of the micelles by cross-linking of the PDMS-sided (cl) methacrylic end groups. The resulting nanoparticles possess the PEG-sided (omega) functional end groups introduced during the synthesis of the amphiphilic diblock copolymer. In the present study, these functionalities are hydrophilic, uncharged hydroxy end groups (-OH), hydrophilic, charged carboxylate (-COOH) end groups, or hydrophobic benzylic end groups (-CH2C6H5).