Strategy for hypertrophic scar therapy: Improved delivery of triamcinolone acetonide using mechanically robust tip-concentrated dissolving microneedle array.

A hypertrophic scar (HS) is a cutaneous condition characterized by deposits of excessive amounts of collagen that produces a raised scar, causing physical, psychological, and cosmetic problems for the patient. The therapeutic efficacy of conventional transdermal drug delivery systems is often limited because the HS tissue is more compact than normal skin. At present, intralesional multi-injection of triamcinolone acetonide (TA) using a syringe is one of the most commonly used treatments for HS. However, the efficacy of this treatment is highly dependent on the skill of the medical professionals administering the injection. Even with co-administration of local anesthetics, traditional injection still causes pain to the patients, resulting in poor compliance. The purpose of this study was to provide an alternative treatment for HS by establishing a novel intradermal delivery system with a dissolving microneedle array (DMNA). To produce needles of higher mechanical strength for successful insertion into the compact and hard HS tissue, hydroxypropyl-ß-cyclodextrin (HP-ß-CD) was added into sodium hyaluronic acid (HA), the needle material. The hydrogen interaction between HP-ß-CD and HA restricted the mobility of the molecular chains, and subsequently increased the elastic modulus of the complex materials. The HP-ß-CD also contributed to improved loading of the hydrophobic drug molecules into the DMNA needle tips. To assess the delivery of TA to the HS site via DMNA, an HS model was established in the ventral skin of New Zealand rabbits' ears. It was found that the value of the scar elevation index was decreased to normal, together with the down regulation of mRNA expressions of Collagen I and transforming growth factor-ß1 (TGF-ß1) following the administration of DMNA containing TA (TA-DMNA). Western blotting results also revealed decreased protein expressions of both Collagen I and TGF-ß1. Hence, TA-DMNA appears to be a promising alternative to multi-injection of TA injection, providing a convenient and low-pain therapeutic strategy for HS treatment.

Design of SnO2 Aggregate/Nanosheet Composite Structures Based on Function-Matching Strategy for Enhanced Dye-Sensitized Solar Cell Performance.

Hierarchical SnO2 nanocrystallites aggregates (NAs) were prepared with a simple room temperature⁻based aqueous solution method followed by simple freeze-drying treatment. The as-prepared SnO2 NAs were subsequently combined with SnO2 nanosheet⁻based structures from the viewpoint of a function-matching strategy, and under an optimized condition, a power conversion efficiency (PCE) of 5.59% was obtained for the resultant hybrid photoanode, a remarkable 60% enhancement compared to that of dye-sensitized solar cells (DSCs) fabricated with bare SnO2 NAs architecture. The significantly enhanced efficiency can be attributed to the combination of the desirable electron transport property obtained by the intentionally introduced SnO2 nanosheets (NSs) and the effectively retained inherent characteristics of SnO2 NAs, i.e., large surface area and strong light-scattering effect. This work provides a promising approach for the rapid development of highly efficient SnO2 photoanode film-based DSCs with the properties of simplicity of operation and control over the photoanode composition.

Comparative studies on glycerol monooleate- and phytantriol-based cubosomes containing oridonin in vitro and in vivo.

To improve the solubility and bioavailability of oridonin (ORI), glycerol monooleate lipid (GMO)- or phytantriol (PYT)-Poloxamer 407-propylene glycol-water systems were firstly used to develop cubosomes containing ORI for oral delivery. These cubosomes prepared through the fragmentation of bulk gels under homogenization conditions of 1200 bar and nine cycles had a mean particle size of around 200 nm with narrow size distribution, and ORI encapsulation efficiency over 85%. Powder X-ray diffraction and differential scanning calorimetry indicated that ORI was in an amorphous or molecular form in the cubosomes. The internal structures of GMO- and PYT-based cubosomes were revealed by small-angle X-ray scattering as a bi-continuous cubic liquid crystalline phase with Im3m and Pn3m geometry, respectively. About 80% of ORI was released in vitro from GMO- and PYT-based cubosomes at 24 h, showing a sustained release kinetics fitted with Higuchi's equation. The pharmacokinetic study in rats showed that the PYT-based cubosomes significantly enhanced the adsorption of ORI as compared to the GMO-based cubosomes and ORI suspension, with evidence of longer half-life and greater relative bioavailability (p < 0.01). Therefore, the PYT-based cubosomes containing ORI might be proposed as a promising candidate carrier for the efficient delivery of drug with therapeutic treatment.

Phytantriol based liquid crystal provide sustained release of anticancer drug as a novel embolic agent.

Phytantriol has received increasing amount of attention in drug delivery system, however, the ability of the phytantriol based liquid crystal as a novel embolic agent to provide a sustained release delivery system is yet to be comprehensively demonstrated. The purpose of this study was to prepare a phytantriol-based cubic phase precursor solution loaded with anticancer drug hydroxycamptothecine (HCPT) and evaluate its embolization properties, in vitro drug release and cytotoxicity. Phase behavior of the phytantriol-solvent-water system was investigated by visual inspection and polarized light microscopy, and no phase transition was observed in the presence of HCPT within the studied dose range. Water uptake by the phytantriol matrices was determined gravimetrically, suggesting that the swelling complied with the second order kinetics. In vitro evaluation of embolic efficacy indicated that the isotropic solution displayed a satisfactory embolization effect. In vitro drug release results showed a sustained-release up to 30 days and the release behavior was affected by the initial composition and drug loading. Moreover, the in vitro cytotoxicity and anticancer activity were evaluated by MTT assay. No appreciable mortality was observed for NIH 3T3 cells after 48 h exposure to blank formulations, and the anticancer activity of HCPT-loaded formulations to HepG2 and SMMC7721 cells was strongly dependent on the drug loading and treatment time. Taken together, these results indicate that phytantriol-based cubic phase embolic gelling solution is a promising potential carrier for HCPT delivery to achieve a sustained drug release by vascular embolization, and this technology may be potential for clinical applications.