Fennel-like nanoaggregates based on polysaccharide derivatives and their application in drug delivery

Self-complementary hydrogen-bond interactions of guanosine: a hub for constructing supra-amphiphilic polymers with controlled molecular structure and aggregate morphology

A supra-amphiphilic polymer (SAP) with controlled molecular structures is constructed, in this work, via self-complementary hydrogen bonding of guanosine groups between a hydrophilic block, poly(N-isopropylacrylamide), and a hydrophobic block, poly(ε-caprolactone). By simply changing the mixing ratio of the guanosine-capped hydrophilic and hydrophobic blocks, a series of SAPs with tailored nanostructures are constructed, which can further self-assemble into different nano-aggregates in solution, including spheres, vesicles and large vesicle micelles. The thermo-induced phase transition of the hydrophilic block induces the fusion and aggregation of the nanoparticles into irregular particles upon heating, which further transform to large compound vesicles after cooling.

Hyaluronic acid-containing ethosomes as a potential carrier for transdermal drug delivery

A hyaluronic acid-containing ethosomes (HA-ES) as the transdermal drug delivery system was prepared in this work, and rhodamine B (RB) was used as a model drug to be encapsulated. The obtained HA-ES-RB was then characterized by the surface morphology, entrapment efficiency, drug loading and the stability. Results showed that the prepared HA-ES-RB was spherical and showed good dispersion as well as the stability, with a particle size of below 100 nm. The skin permeation experiments were carried out in vitro with the Franz diffusion cells and the rat dorsal skins were used. It was found that the penetration effect of HA-ES-RB was much better than that of ES-RB. The fluorescence microscopy image showed that HA-ES-RB penetrated into the deepest dermis. The excellent transdermic drug delivery effect of HA-ES-RB maybe attributed from its smaller size, hydration of hyaluronic acid as well as greater potential targeting to skin and skin appendages of liposomal carriers. Moreover, the HA-ES delivery system showed non-cytotoxicity to normal cells, indicating a good biocompatibility. This work provded a hyaluronic acid-containing ethosomes which can offer a quick, high efficient, safe and self-administered transdermal drug delivery system.

The Fabrication of rGO/(PLL/PASP)3 @DOX Nanorods with pH-Switch for Photothermal Therapy and Chemotherapy

The development of well-controlled drug carriers that are stable and highly effective for the delivery of anticancer agents is challenging. Herein, we report a novel pH-controlled drug delivery system, utilizing reducing graphene oxide (rGO)-polymer self-assembly films as carriers, for the preparation of effective drug nanorods and nanoparticles. In this system, the rGO-polymer carriers were constructed by the alternating assembly of poly-l-lysine (PLL) and polyaspartic acid (PASP) around the rGO sheets. Furthermore, the rGO-polymer cores, which possess a positively charged surface as the desired template, could assemble with negatively charged doxorubicin (DOX) via electrostatic interactions. The DOX embedding efficiency and the morphology of the drug nanocomposites could be controlled by the number of rGO-polymer bilayers and concentration of the rGO-polymer bilayers and the initial DOX concentration. Importantly, the release of DOX could be regulated by controlling the pH and by using a NIR laser. Under acidic conditions, the interactions between the PASP layer and DOX molecules can be broken, resulting in gradual release of the DOX molecules. Upon NIR irradiation, the release of DOX could be further accelerated and a photothermal effect from rGO induced. Cellular uptake and cytotoxicity experiments indicate that the drug nanocomposites possess effective anticancer activity. Thus, in this work, we present a useful strategy for the fabrication of pH-responsive drug nanocomposites for combined photothermal and chemical therapy. The nanocomposite can be used as a potential drug delivery system for practical cancer treatment.