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Diabetes is a common global disease that causes immense suffering for individuals and huge costs for the health care system. To minimize complications such as organ degeneration, diabetic patients are required to undergo treatments to maintain the blood glucose level in the normal range, ideally mimicking normal insulin secretion. The normal physiological insulin secretion pattern in healthy individuals consists of a base (basal) level through the day and increased secretion after meals (bolus insulin). Thus effective treatments may combine long acting, low-level insulin therapy with boosts of short acting insulin and/or oral agents. To achieve long term management of basal insulin level, an injectable insulin-loaded gel composed of self-assembled nanoparticles from carboxymethyl-hexanoyl chitosan (CHC) and integrated lysozyme for controlled biodegradation and insulin release was developed. In vitro characterizations and evaluations confirmed that lysozyme was active on CHC and that the amount of lysozyme in a CHC hydrogel determined the degradation and insulin release rate. The degradation products were found to be highly cytocompatible using a cell assay. In vivo evaluation of the system in a diabetic mouse model revealed that the fasted blood glucose level could be maintained in the normal range for 10 days with a single injection of insulin-loaded CHC-lysozyme gel. The insulin-loaded CHC-lysozyme gels clearly show promise for use as a novel injectable long-acting insulin delivery system, with potential to manage the basal insulin level for many days with a single injection. [ABSTRACT FROM AUTHOR]

Abstract: Ultrathin mesoporous TiO2 coatings with a wormhole-like architecture were synthesized using evaporation-induced self-assembly method. The morphological and chemical structures of TiO2 films were characterized using small-angle and large-angle X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transformed infrared spectrometry (FTIR). The films demonstrated a thickness of ∼120nm and open-porous nanostructure. By taking advantage of the tortuosity of the worm-like mesoporous architecture associated with the chemistry of the TiO2 film, a sustained drug release using ibuprofen and vancomycin as model molecules from the film was determined. Besides, adhesion behavior of osteoblast cells, together with an in vitro apaptitic formation substantiated the cytocompatibility and bioactivity of the mesoporous TiO2 films. Such combined bioactive and drug-releasing functions of the TiO2 films with worm-like mesoporosity ensure an improved therapeutic performance for potential applications included orthopedics, dentistry, and drug delivery. [Copyright &y& Elsevier]

Abstract: A flexible drug delivery device was designed and fabricated using electrophoretic deposition of drug-carrying magnetic core-shell Fe3O4 at SiO2 nanoparticles onto an electrically conductive flexible PET substrate. The PET substrate was first patterned to a desired layout and subjected to deposition. In doing so, a uniform and nanoporous membrane could be produced. After lamination of the patterned membranes, a final chip-like device of thickness less than 0.5mm is formed that is used for controlled delivery of an anti-epileptic drug, i.e., ethosuximide (ESM). The release of useful drugs can be controlled by directly modulating the magnetic field, and the chip is capable of demonstrating a variety of release profiles (i.e., slow release, sustained release, step-wise release and burst release profiles). These profiles can follow a wide spectrum of patterns ranging from zero to pulsatile release kinetics depending on the mode of magnetic operation. When the magnetic field was removed, the release behavior was instantly ceased, and vice versa. A preliminary in-vivo study using Long–Evans rat model has demonstrated a significant reduction in spike-wave discharge after the ESM was burst released from the chip under the same magnetic induction as in-vitro, indicating the potential application of the drug delivery chip. The flexible and membrane-like drug delivery chip utilizes drug-carrying magnetic nanoparticles as the building blocks that ensure a rapid and precise response to magnetic stimulus. Moreover, the flexible chip may offer advantages over conventional drug delivery devices by improvement of dosing precision, ease of operation, wider versatility of elution pattern, and better compliance. [Copyright &y& Elsevier]