We describe a simple and versatile method to fabricate conducting polymer hydrogels via supramolecular self-assembly between polymers and multivalent cations; the as-prepared hydrogels are potentially applicable in the fields of electrosensors, chemical release and artificial muscles.

A series of amphiphilic poly(L-leucine)-block-poly(ethylene glycol)-block-poly(L-leucine) (PLL-PEG-PLL) hybrid triblock copolymers have been synthesized. All the blocks in this system have good biocompatibility and low toxicity. The PLL-PEG-PLL copolymers could self-assemble into micelles with PLL blocks as the hydrophobic core and PEG blocks as the hydrophilic shell, which were characterized by FT-IR, (1) H NMR, and transmission electron microscopy analysis. The critical micellar concentration of the copolymer was 95.0 mg · L(-1) . The circular dichroism spectrum shows that the PLL segments adopt a unique α-helical conformation, which is found to play an important role in controlling the drug release rate. The drug release could be effectively sustained by encapsulation in the micelles. The copolymers may have potential applications in drug delivery.

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Low molecular weight poly(3-caprolactone) (PCL) and a-cyclodextrin (a-CD) favor forming crystallized peseudopolyrotaxanes in most of solvents, which impedes their biomedical application. This work provides an example of site-specific polymer functionalization of PCL to control the hierachical assembly with CDs to form novel supramolecular polymer micelles (SMPMs). The unique design of functional PCL includes the introduction of anticancer drug doxorubicin (Dox) with a larger molecular volume as the steric group into the backbone of PCL to realize the partial inclusion complex of PCL with a-CD. This inclusion complex can then self assemble into SMPMs with an average size of around 20 nm in aqueous solution due to the hydrophobic-hydrophilic interaction. The structure and morphology of the SMPMs were investigated and revealed by comprehensive characterizations including 1 HNMR, XRD and TEM, TGA etc., their controlled drug release and cell internalization behavior were also explored. The above proof of concept paves the way for a new strategy for selfassembly and overcomes the dispersion of pseudopolyrotaxanes, also, the micelles formed show great promise in biomedical applications, especially in controlled drug release.