Confinement of carbon dots localizing to the ultrathin layered double hydroxides toward simultaneous triple-mode bioimaging and photothermal therapy.

It is a great challenge to develop multifunctional nanocarriers for cancer diagnosis and therapy. Herein, versatile CDs/ICG-uLDHs nanovehicles for triple-modal fluorescence/photoacoustic/two-photon bioimaging and effective photothermal therapy were prepared via a facile self-assembly of red emission carbon dots (CDs), indocyanine green (ICG) with the ultrathin layered double hydroxides (uLDHs). Due to the J-aggregates of ICG constructed in the self-assembly process, CDs/ICG-uLDHs was able to stabilize the photothermal agent ICG and enhanced its photothermal efficiency. Furthermore, the unique confinement effect of uLDHs has extended the fluorescence lifetime of CDs in favor of bioimaging. Considering the excellent in vitro and in vivo phototherapeutics and multimodal imaging effects, this work provides a promising platform for the construction of multifunctional theranostic nanocarrier system for the cancer treatment.

New biocompatible hydroxy double salts and their drug delivery properties.

Two biocompatible hydroxy double salts (HDSs) were synthesised for the first time and loaded with active pharmaceutical ingredients. Drug release was studied from these intercalates, and sustained release observed. The HDS-drug composites were further formulated into tablets which were found to comply with pharmacopeia requirements for delayed and extended release dosage forms.

Pulsatile drug release from electrospun poly(ethylene oxide)-sodium alginate blend nanofibres.

Novel and highly tuneable pulsatile drug delivery systems have been prepared through the electrospinning of a blend of poly(ethylene oxide) (PEO), sodium alginate (SA), and sodium ibuprofen (SI). The resultant fibres contain crystallites of SI embedded in a PEO-SA matrix, and rather than being obtained as flat mats on the collector plate form novel three dimensional structures extending upwards the needle. Fibres were prepared with a range of loadings of SI and SA. It was found that at pH 6.8 (reminiscent of the intestinal tract) the fibres dissolve very rapidly, freeing all the embedded drug within ca. 20 minutes. However, at pH 3 (representative of the stomach pH in the fed state or in older patients) an unusual two stage release mechanism is seen. This comprises a rapid burst release, followed by a period where no further drug is released for ca. 120-150 minutes, and then a final stage of release freeing the remainder of the drug into solution. The amount of release in the initial stage, and the length of time between the first and final drug release stages, can be controlled by adjusting the SI and SA contents of the fibres respectively. This results in highly tunable pulsatile release materials.