Rational design of shear-thinning supramolecular hydrogels with porphyrin for controlled chemotherapeutics release and photodynamic therapy

An amphiphilic porphyrin-cored, star-shaped poly (ε-caprolactone)-b-poly (ethylene glycol) (SPPCL-b-PEG) copolymer was synthesized and used as a building block for constructing supramolecular hydrogels. With the aid of α-cyclodextrin (α-CD), thixotropic and reversible supramolecular hydrogel could be formed by copolymers based on the host-guest inclusion complexation (IC). Due to the biodegradable and biocompatible properties, this IC-based supramolecular hydrogel was used as carrier for doxorubicin (DOX) delivery systems. The release results presented a triphasic drug-release profile and the release of this system lasted more than 3 weeks. Also, upon irradiation with light (650 nm), cytotoxic singlet oxygen (¹O₂) could be generated by porphyrin core and easily released from hydrogel matrix. Considering that both sustained-release drug delivery of hydrogels and porphyrin for photodynamic therapy (PDT) were achieved in a combined compound, this shear-thinning supramolecular hydrogel with porphyrin was elaborately designed as a promising replacement therapy to medium or advanced cancer for surgery.