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In order to achieve efficient siRNA delivery to the brain, we designed a novel polyion complex (PIC) micelles composed of rabies virus glycoprotein (RVG) peptide tagged PEGylated polyasparthydrazide (PAHy) derivatives. The synthesized derivatives were characterized using (1)H NMR. The PIC micelles were formed by electrostatic attraction between the polymer and siRNA. Then the micelles were decorated with RVG using PEG as a linker. The physiochemical properties of micelles, such as gel retardation assay, zeta potential, particle size, morphology and serum stability, were investigated. Moreover, the cytotoxicity, cellular uptake, gene silencing efficiency and in vivo distribution of micelles were also evaluated systematically. Compared with unmodified micelles, RVG-modified micelles can be more easily internalized by the neuro2a cells and efficiently silence gene expression. In vivo animal experiments further confirmed that RVG modified micelles had brain targeting ability. These results demonstrated that RVG-modified micelles were promising carriers for siRNA delivery to the brain., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: To test the effect of aqueous eye drops containing a high concentration of disulfiram (DSF) in a cyclodextrin- based drug delivery system. This system increases both the drug solubility in aqueous eye drops and the permeability of drug into the rabbit eye, by the formation of a drug-cyclodextrin inclusion complex, and so enhances the ocular bioavailability and anti-cataract effect of DSF., Methods: The DSF and hydroxypropyl-beta-cyclodextrin (HPbetaCD) inclusion (DSF/HPbetaCD) was studied using solubility methods, IR spectra and X-ray diffraction patterns. Suitable formulations for DSF eye drops were first identified by a trans-corneal penetration experiment in vitro. Finding a new p-bromophenacyl bromide (p-BPB) derivative reagent for diethyldithiocarbamic acid (DDC), which was a metabolite of DSF, allowed precise determination of the contents of DSF in aqueous humor. The ocular bioavailability was calculated by a transcorneal experiment of DSF in vivo. The lens opacity of a selenite-induced cataract in rat pups was monitored using a slit lamp with an anterior eye segment analysis system., Results: The formation of DSF/HPbetaCD inclusion and the addition of hydroxypropylmethylcellulose (HPMC), as a penetration enhancer, played very important roles in increasing the ocular bioavailability of DSF. DSF eye drops, with a formulation of 1.26% (w/v) DSF/HPbetaCD inclusion, 0.01% (w/v) HPMC, 0.005% (w/v) benzalkonium chloride and 0.9% (w/v) sodium chloride, inhibited the onset of selenite-induced cataracts effectively., Conclusions: The cyclodextrin-based drug delivery system enhances both the solubility of DSF in aqueous eye drops and permeability of the drug into the rabbit eye. DSF ocular bioavailability in rabbit aqueous humor exceeded those reported for the DSF ophthalmic preparation. DSF eye drops effectively prevent the development of selenite-induced cataracts.

Objective: To explore the suitable application of MCM-41 (Mobil Composition of Matter number forty-one)-type and MCM-48-type mesoporous silica in the oral water insoluble drug delivery system. Methods: Cilostazol (CLT) as a model drug was loaded into synthesized MCM-48 (Mobil Composition of Matter number forty-eight) and commercial MCM-41 by three common methods. The obtained MCM-41, MCM-48 and CLT-loaded samples were characterized by means of nitrogen adsorption, thermogravimetric analysis, ultraviolet-visible spectrophotometry, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry and powder X-ray diffractometer. Results: It was found that solvent evaporation method was preferred according to the drug loading efficiency and the maximum percent cumulative drug dissolution. MCM-48 with 3D cubic pore structure and MCM-41 with 2D long tubular structure are nearly spherical particles in 300-500 nm. Nevertheless, the silica carriers with similar large specific surface areas and concentrating pore size distributions (978.66 m2/g, 3.8 nm for MCM-41 and 1108.04 m2/g, 3.6 nm for MCM-48) exhibited different adsorption behaviors for CLT. The maximum percent cumulative drug release of the two CLT/silica solid dispersion (CLT-MCM-48 and CLT-MCM-41) was 63.41% and 85.78% within 60 min, respectively; while in the subsequent 12 h release experiment, almost 100% cumulative drug release were both obtained. In the pharmacokinetics aspect, the maximum plasma concentrations of CLT-MCM-48 reached 3.63 mg/L by 0.92 h. The AUC0-∞ values of the CLT-MCM-41 and CLT-MCM-48 were 1.14-fold and 1.73-fold, respectively, compared with the commercial preparation. Conclusion: Our findings suggest that MCM-41-type and MCM-48-type mesoporous silica have great promise as solid dispersion carriers for sustained and immediate release separately. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to develop spherical mesocellular foam (MCF) loaded with a poorly water-soluble drug, intended to be orally administered, able to improve the dissolution rate and enhance the drug loading capacity. Spherical MCF with a continuous 3-D pore system was synthesized using Pluronic 123 triblock polymer (P123) as a surfactant coupled with cetyltrimethyl ammonium bromide (CTAB) as a co-surfactant. A model drug, simvastatin (SV), was loaded onto spherical MCF via a procedure involving a combination of adsorption equilibrium and solvent evaporation. The drug release rate and the drug loading efficiency of spherical MCF were compared with those of fibrous SBA-15. Investigations using nitrogen adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and HPLC demonstrated the successful incorporation of SV into the MCF host. It was found that spherical MCF has a high drug loading efficiency up to 37.5%, and higher than that of fibrous SBA-15 with a pore diameter of 6.5nm. It is worth noting that fast release rate of SV was obtained from spherical MCF compared with SBA-15 and pure crystalline SV using enzyme-free simulated intestinal fluid (SIF, pH 6.8). [Copyright &y& Elsevier]

Limited drug loading and incomplete drug release are two major obstacles that traditional polymeric microneedles (MNs) have to overcome. For smart controlled-release MNs, since drug release duration is uncertain, a clear indication of the finish of drug release is also important for patient guidance on the timing of the next dose. In this study, MN with a triple structure of a glucose-responsive shell, loaded insulin powders and a colored propelling inner core (inspired by the mechanism of osmotic pump) was innovatively constructed. The MN patch could release insulin according to blood glucose levels (BGLs) and had excellent drug loading, more complete drug release, and good drug stability, which significantly prolonged the normoglycemic time. An approximately 0.3 cm2 patch has a hypoglycemic effect on diabetic mice for up to 24 h. Moreover, the fading of the inner core could indicate the release process of the loaded drug and can help to facilitate uninterrupted closed loop therapy for patients. The designed triple MN structure is also suitable, and can be used in the design of other smart MN drug delivery systems to further improve their drug loading capacity and simultaneously achieve more complete, smart controlled and visualized drug release. [Display omitted] • The glucose-responsive microneedle also enables the visualization of drug release. • The triple structure of the microneedle can promote more complete drug release. • A 0.3 cm2 patch has a hypoglycemic effect on diabetic mice for up to 24 h. [ABSTRACT FROM AUTHOR]

In this work, a peptide derived fromthe rabies virus glycoprotein(RVG) was linked to siRNA/trimethylated chitosan (TMC) complexes throughbifunctional PEG for efficient brain-targeted delivery of siRNA. Thephysiochemical properties of the complexes, such as siRNA complexingability, size and ζ potential, morphology, serum stability,and cytotoxicity, were investigated prior to studying the cellularuptake, in vitrogene silencing efficiency, and in vivobiodistribution. The RVG-peptide-linked siRNA/TMC–PEGcomplexes showed increased serum stability, negligible cytotoxicity,and higher cellular uptake than the unmodified siRNA/TMC–mPEGcomplexes in acetylcholine receptor positive Neuro2a cells. The potentknockdown of BACE1, a therapeutic target in Alzheimer’s disease,demonstrated the gene silencing efficiency. In vivoimaging analysis showed significant accumulation of Cy5–siRNAin the isolated brain of mice injected with RVG-peptide-linked complexes.Therefore, the RVG-peptide-linked TMC–PEG developed in thisstudy can be used as a potential carrier for delivery of siRNA tothe brain. [ABSTRACT FROM AUTHOR]

Abstract: Fibrous ordered mesoporous carbon (FOMC) was developed as a new drug delivery system for loading an insoluble drug, designed to be orally administered, and then to enhance the drug loading capacity, improve the dissolution rate, enhance the oral bioavailability and reduce the gastric damage. Celecoxib (CEL) was chosen as a model drug. The nanostructures and effect of different pore sizes (4.4–7.0nm) on drug loading and release properties were studied. The results showed that FOMC has a high drug loading capacity (0.599g/g, drug weight/carrier weight) and the dissolution rate of CEL from FOMC was much faster than pure crystalline CEL using buffer (pH 6.8) as a dissolution medium. Moreover, the oral bioavailability of CEL loaded into FOMC was significantly improved compared with that of CEL capsules and the gastric damage caused by CEL which was loaded in FOMC was also reduced, demonstrating the protective effect of FOMC. [Copyright &y& Elsevier]

Abstract: In this study, uniform mesoporous carbon spheres (UMCS) with 3-D pore system and fibrous ordered mesoporous carbon (FOMC) with 2-dimensional hexagonal mesoporous structure were studied as drug carriers for oral drug delivery system. Lovastatin (LOV), which has low water solubility, was chosen as a model drug. Drug release rate and degree of drug loading of UMCS and FOMC were compared. The effects of different pore channel structures and pore sizes on LOV uptake and release were systematically investigated. Cytotoxicity of UMCS and FOMC on human colon carcinoma (Caco-2) cells were also studied. The results indicate that UMCS has a higher degree of drug loading (up to 36.26% drug weight/total weight) compared with FOMC. The dissolution rate of LOV from UMCS was found to be markedly increased compared with pure crystalline LOV, and the dissolution rate of LOV from FOMC was relatively sustained compared with UMCS, and both UMCS and FOMC exhibited a weak cytotoxicity at tested concentrations (10–800μg/ml). [Copyright &y& Elsevier]

Abstract: The evaluation of N-trimethyl chitosan (TMC)-coated liposomes containing Coenzyme Q10 as potential ophthalmic drug delivery system was carried out. Firstly, transcorneal permeation studies were conducted at 34°C using a side-by-side diffusion apparatus. The transport process of the fluorescent marker, rhodamine B, across the corneal epithelium was visualized with confocal laser scanning microscopy. Secondly, the human lens epithelial cells (HLECs) were cultured without or with Coenzyme Q10 followed by addition of H2O2. The cell viability and apoptosis were evaluated. The permeability coefficient for rhodamine B with TMC-coated liposomes increased more than two times in comparison with the value obtained for solution as control, from (0.42±0.018)×105 cms−1 to (1.31±0.030)×105 cms−1. Confocal laser scanning microscopy revealed that a TMC coating enhanced the transepithelial transport, dependent on the TMC concentration and contacting time. Coenzyme Q10 elevated the cell viability and reduced the oxidative damage with the decreased percentage of apoptotic cells in a positive concentration-dependent manner. The ATP content of liposome-treated cells was increased about 2-fold compared with that of H2O2-treated cells. Together, our findings demonstrate that with the enhanced permeation effect of the TMC coating, Coenzyme Q10-loaded TMC-coated liposomes appear to be a promising ophthalmic drug delivery carrier with an efficacy in protecting HLECs against H2O2-induced oxidative damage. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to develop mesoporous silica nanoparticles (MSNs) loaded with a poorly water-soluble drug, intended to be orally administered, able to improve the dissolution rate and enhance the drug loading capacity. Spherical MSNs were synthesized using an organic template method in an oil/water phase, and large pore diameter MSNs were functionalized with aminopropyl groups through postsynthesis. MSNs as well as the resulting functionalized MSNs were investigated as matrices for loading and release of the model drug telmisartan (TEL). The effects of different pore sizes and surface chemical groups on TEL uptake and release were systematically studied using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and HPLC. The total pore volume and the pore diameter of MSNs were the two main factors limiting the maximum drug load capacity. MSNs allow a very high drug loading of about 60% in weight. The release rate of TEL from MSNs with a pore diameter of 12.9nm was found to be effectively increased and the release rate of TEL from the functionalized MSNs was effectively controlled compared with that from the unmodified MSNs. We believe that the present study will help in the design of oral drug delivery systems for the dissolution enhancement and/or sustained release of poorly water-soluble drugs. [Copyright &y& Elsevier]

Abstract: Anti-neuroexcitation peptide (ANEP) is a promising candidate for the treatment of neuroexcitation-associated diseases. N-Trimethyl chitosan (TMC) with different degrees of quaternization was synthesized, characterized and evaluated as a brain-targeting delivery vehicle for ANEP. ANEP-loaded TMC nanoparticles were prepared by ionic crosslinking of TMC with tripolyphosphate (TPP). The optimized formulation of nanoparticles consisted of TMC with a degree of quaternization (DQ) of 36.1% and TPP solution with a concentration of 0.6mg/mL. The mean encapsulation efficiency and loading capacity of the optimum formulation was 80.63% and 185.4μg/mL, respectively, while the mean particle size, zeta potential, and pH value were 255nm, 32.0mV and 6.61, respectively. ANEP was labeled with FITC for in vivo tissue distribution experiments. The results showed that the targetability of ANEP to brain was significantly increased by TMC nanoparticles. Absorptive-mediated transcytosis was believed to be the main pathway for the brain-targeting of FITC–ANEP–TMC/NPs. These findings demonstrate that TMC nanoparticles are potentially useful brain-targeting delivery systems for ANEP. [Copyright &y& Elsevier]