Multi-Responsive Polypeptidosome: Characterization, Morphology Transformation, and Triggered Drug Delivery

A sweet polydopamine nanoplatform for synergistic combination of targeted chemo-photothermal therapy

Inspired by sweet or sugar-coated bullets that are used for medications in clinics and the structure and function of biological melanin, a novel kind of sweet polydopamine nanoparticles and their anticancer drug doxorubicin loaded counterparts are prepared, which integrate an active targeting function, photothermal therapy, and chemotherapy into one polymeric nanocarrier. The oxidative polymerization of lactosylated dopamine and/or with dopamine are performed under mild conditions and the resulting sweet nanoparticles are thoroughly characterized. When exposed to an 808 nm continuous-wave diode laser, the magnitude of temperature elevation not only increases with the concentration of nanoparticles, but can also be tuned by the laser power density. The nanoparticles possess strong near infrared light absorption, high photothermal conversion efficiency, and good photostability. The nanoparticles present tunable binding with RCA120 lectin and a targeting effect to HepG2 cells, confirmed by dynamic light scattering, turbidity analysis, MTT assay, and flow cytometry. Importantly, the sweet nanoparticles give the lowest IC50 value of 11.67 μg mL(-1) for chemo-photothermal therapy compared with 43.19 μg mL(-1) for single chemotherapy and 67.38 μg mL(-1) for photothermal therapy alone, demonstrating a good synergistic effect for the combination therapy.

Bioactive polymersomes self-assembled from amphiphilic PPO-glycopolypeptides: synthesis, characterization, and dual-dye encapsulation

Glycopolypeptide-based polymersomes have promising applications as vehicles for targeted drug delivery because they are capable of encapsulating different pharmaceuticals of diverse polarity as well as interacting with specific cell surfaces due to their hollow structural morphology and bioactive surfaces. We have synthesized glycopolypeptide-b-poly(propylene oxide) by ROP of glyco-N-carboxyanhydride (NCA) using the hydrophobic amine-terminated poly(propylene oxide) (PPO) as the initiator. This block copolymer is composed of an FDA-approved PPO hydrophobic block in conjugation with hydrophilic glycopolypeptides which are expected to be biocompatible. We demonstrate the formation of glycopolypeptide-based polymersomes from the self-assembly of glycopolypeptide-b-poly(propylene oxide) in which the presence of an ordered helical glycopolypeptide segment is required for their self-assembly into spherical nanoscale (∼50 nm) polymersomes. The polymersomes were characterized in detail using a variety of techniques such as TEM, AFM, cryo-SEM, and light-scattering measurements. As a model for drugs, both hydrophobic (RBOE) and hydrophilic (calcein) dyes have been incorporated within the polymersomes from solution. To substantiate the simultaneous entrapment of the two dyes, spectrally resolved fluorescence microscopy was performed on the glycopeptide polymersomes cast on a glass substrate. We show that it is possible to visualize individual nanoscale polymersomes and effectively probe the dyes' colocalization and energy-transfer behaviors therein as well as investigate the variation in dual-dye encapsulation over a large number of single polymersomes. Finally, we show that the galactose moieties present on the surface can specifically recognize lectin RCA120, which reveals that the polymersomes' surface is indeed biologically active.

NIR-responsive polypeptide copolymer upconversion composite nanoparticles for triggered drug release and enhanced cytotoxicity

Near infrared light-responsive polypeptide copolymer upconversion composite nanoparticles exhibited controllable drug release and triggered cytotoxicity useful for on-demand drug delivery and cancer therapy.

Facile synthesis of photolabile dendritic-unit-bridged hyperbranched graft copolymers for stimuli-triggered topological transition and controlled release of Nile red

Successive RAFT SCVP and ROP were used to generate novel hyperbranched graft copolymers with the ability for the photo-triggered degradation and accelerative release of hydrophobic dye.

Comb-like poly(l-cysteine) derivatives with different side groups: synthesis via photochemistry and click chemistry, multi-responsive nanostructures, triggered drug release and cytotoxicity

A series of comb-like graft polypeptides having different side groups and tunable grafting ratios were prepared by sequential photocleavage reactions and Michael-type thiol–ene addition, which provides a promising platform for on-demand nanomedicine and cancer therapy.

Micellar assembly of a photo- and temperature-responsive amphiphilic block copolymer for controlled release

Block copolymeric micellar nanoparticles in response to light and temperature change have been constructed for the controlled release of encapsulated molecules under stimulation with light and temperature change.