Yanyu Xiao

Lactoferrin-modified poly(ethylene glycol)-grafted BSA nanoparticles as a dual-targeting carrier for treating brain gliomas.

In this study, a dual-targeting drug delivery system based on bovine serum albumin nanoparticles (BSA-NPs) modified with both lactoferrin (Lf) and mPEG2000 loading doxorubicin (DOX) was designed, and its blood-brain barrier (BBB) penetration and brain glioma cells targeting properties were explored. BSA-NPs were prepared by a desolvation technique, and mPEG2000 was incorporated onto the surface of BSA-NPs by reacting with the free amino-group of BSA to form mPEG2000-modified BSA-NPs (P2000-NPs). Finally, Lf-modified P2000-NPs (Lf-NPs) was obtained by absorbing Lf onto the surface of P2000-NPs via the positive and negative charges interaction at physiological pH. Three levels of mPEG2000 and Lf-modified NPs were prepared and characterized, respectively. The uptake and potential cytotoxicity of different DOX preparations in vitro by the primary brain capillary endothelial cells (BCECs) and glioma cells (C6) were investigated. The dual-targeting effects were studied on the BBB model in vitro, BCECs/C6 glioma coculture model in vitro, and C6 glioma-bearing rats in vivo, respectively. The results exhibited that, with the increase of the amount of both mPEG2000 and Lf, the particle size of NPs increased and its zeta potential decreased. The in vivo pharmacokinetics study in healthy rats exhibited that P2000-NPs with a high level of mPEG2000 (P2000H-NPs) had longer circulation time in vivo. Compared to other NPs, Lf-NPs with high level of both Lf and mPEG2000 (LfH-NPs) showed the strongest cytotoxicity and the highest effectiveness in the uptake both in BCECs and C6 as well as improved the dual-targeting effects. Body distribution of DOX in different formulations revealed that LfH-NPs could significantly increase the accumulation of DOX in the brain, especially at 2 h postinjection (P < 0.05). In conclusion, Lf-NPs were a prospective dual-targeting drug delivery system for effective targeting therapy of brain gliomas.

Effect of octreotide-polyethylene glycol(100) monostearate modification on the pharmacokinetics and cellular uptake of nanostructured lipid carrier loaded with hydroxycamptothecine.

A new conjugate, octreotide-polyethylene glycol(100) monostearate (OPMS), was developed for the enhancement of targeting delivery of hydroxycamptothecine (HCPT) loaded in nanostructured lipid carrier (NLC). 2 × 10(-3) and 5 × 10(-3) mmol of OPMS were respectively used to modify NLC so that the targeted nanocarriers with low and high ligand density were obtained. For comparison, the pegylated NLCs without octreotide were prepared by adding equal molar amounts of polyethylene glycol(100) monostearate (PGMS). The relation between the modification levels and properties of various NLCs were studied in vivo and in vitro. At a high modification level, a slower release rate of HCPT and the more stable nanocarriers was achieved. At the same time, the fixed aqueous layer thickness (FALT) and average surface density of PEG chains (SD(PEG)) was increased, but the distance (D) between two neighboring PEG grafting sites became narrower. The in vivo pharmacokinetic study in healthy rat indicated that the modified NLCs had a longer circulation than NLC (P < 0.05) due to pegylation effect and OPMS modified NLCs had larger MRT and AUC(0-t) than that of PGMS modified NLCs at the same modification level. Furthermore, the florescence microscopy observation also showed the targeting effect of octreotide modification on somatostatin receptors (SSTRs) of tumor cell (SMMC-7721). The uptake of SMMC-7721 was much more than that of normal liver cell (L02) for OPMS modified NLC, and the highest uptake was observed for 5 × 10(-3) mmol of OPMS modified one. No obvious difference was found among the L02 uptake of OPMS modified NLCs and NLC, but their uptake was higher than that of PGMS modified NLCs. All the results indicated that the OPMS highly modified NLCs would improve the effect of antitumor therapy by inhibiting the degradation, evading RES and enhancing the drug uptake of tumor cells.

Octreotide-modification enhances the delivery and targeting of doxorubicin-loaded liposomes to somatostatin receptors expressing tumor in?vitro and in?vivo

Octreotide is believed to be the ligand of somatostatin receptors (SSTRs) which are widely used in tumor diagnosis and clinical therapy. In the present work, a new targeting conjugate, octreotide-polyethylene glycol-phosphatidylethanolamine (Oct-PEG-PE), was developed for the assembling of liposome, and the effect of octreotide-modification on the enhancement of the delivery and targeting of doxorubicin-loaded liposomes was investigated in vitro and in vivo. Oct-PEG-PE was synthesized by a three-step reaction involving two derivative intermediate formations of bis (p-nitrophenyl carbonate)-PEG ((pNP)(2)-PEG) and pNP-PEG-PE. The Oct-modified and unmodified liposomes (DOX-OL and DOX-CL) were prepared by the ammonium sulfate gradient method. Both drug uptake assay and cell apoptosis assay suggested that DOX-OL noticeably increased the uptake of DOX in SMMC-7721 cells and showed a more significant cytotoxicity, compared with DOX-CL. The effect of DOX-OL was remarkably inhibited by free octreotide. In contrast, no significant difference in drug cytotoxicity was found between DOX-OL and DOX-CL in CHO cells without obvious expression of SSTRs. The study of ex vivo fluorescence tissues imaging of BALB/c mice and in vivo tissue distribution of B16 tumor-bearing mice indicated that DOX-OL caused remarkable accumulation of DOX in melanoma tumors and the pancreas, in which the SSTRs are highly expressed.

Hierarchical targeted hepatocyte mitochondrial multifunctional chitosan nanoparticles for anticancer drug delivery.

The overwhelming majority of drugs exert their pharmacological effects after reaching their target sites of action, however, these target sites are mainly located in the cytosol or intracellular organelles. Consequently, delivering drugs to the specific organelle is the key to achieve maximum therapeutic effects and minimum side-effects. In the work reported here, we designed, synthesized, and evaluated a novel mitochondrial-targeted multifunctional nanoparticles (MNPs) based on chitosan derivatives according to the physiological environment of the tumor and the requirement of mitochondrial targeting drug delivery. The intelligent chitosan nanoparticles possess various functions such as stealth, hepatocyte targeting, multistage pH-response, lysosomal escape and mitochondrial targeting, which lead to targeted drug release after the progressively shedding of functional groups, thus realize the efficient intracellular delivery and mitochondrial localization, inhibit the growth of tumor, elevate the antitumor efficacy, and reduce the toxicity of anticancer drugs. It provides a safe and efficient nanocarrier platform for mitochondria targeting anticancer drug delivery.

A novel LDL-mimic nanocarrier for the targeted delivery of curcumin into the brain to treat Alzheimer's disease.

In this study, a novel low density lipoprotein (LDL)-mimic nanostructured lipid carrier (NLC) modified with lactoferrin (Lf) and loaded with curcumin (Cur) was designed for brain-targeted delivery, and its effect on controlling the progression of Alzheimers disease (AD) in rats was evaluated. NLC with the composition resembling the lipid portion of LDL was prepared by using solvent evaporation method. Lf was adsorbed onto the surface of NLC via electrostatic interaction to yield Lf modified-NLC (Lf-mNLC) as the LDL-mimic nanocarrier. In order to make sure more Lf was adsorbed on the surface of NLC, negatively charged carboxylated polyethylene glycol (100) monostearate (S100-COOH) was synthesized and anchored into NLC. Different levels of S100-COOH (0-0.02 mmol) and Lf modified NLC (0.5-2.5 mg/mL of Lf solution) were prepared and characterized. The uptake and potential cytotoxicities of different preparations were investigated in the brain capillary endothelial cells (BCECs). An AD model of rats was employed to evaluate the therapeutic effects of Lf-mNLC. The results indicate that Lf-mNLC with a high level of Lf showed the maximum uptake in BCECs (1.39 folds greater than NLC) as cellular uptake of Lf-mNLC by BCECs was found to be mediated by the Lf receptor. FRET studies showed Cur still wrapped inside NLC after uptake by BCECs, demonstrating stability of the carrier as it moved across the BBB. Ex vivo imaging studies exposed Lf-mNLC could effectively permeate BBB and preferentially accumulate in the brain (2.78 times greater than NLC). Histopathological evaluation confirmed superior efficacy of Lf-mNLC in controlling the damage associated with AD. In conclusion, Lf-mNLC is a promising drug delivery system for targeting therapy of brain disease.

ROS-triggered and regenerating anticancer nanosystem: An effective strategy to subdue tumor's multidrug resistance

Drug delivery strategies utilizing tumor microenvironment are recognized as a critical doorway to overcome multidrug resistance (MDR). However, the variability of tumor microenvironment at different disease stages would definitely minimize stimuli generation and eventually the therapeutic effects of these stimuli sensitive systems. Herein, we report a unique reactive oxygen species (ROS) triggered nanosystem that can replenish the ROS upon disassembly to maintain its high level. This was accomplished by a new amphiphilic polymer (TBH) composed of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS), hyaluronic acid (HA) and arylboronic ester. As a linker of TPGS to HA, arylboronic ester could efficiently degrade in response to ROS resulting in dismantling of nanosystem followed by rapid release of TPGS. Owing to ROS inducing activity of TPGS with mitochondrial respiratory complex II, ROS regeneration was observed for TBH nanosystem both in MCF-7/ADR cells and tumor tissues xenografted with MCF-7/ADR cells. Furthermore, doxorubicin-loaded TBH nanosystem (DOX-TBH) revealed higher drug cytotoxicity due to enhanced retention effect on account of ROS triggered DOX release and P-gp inhibitory mechanism of TPGS. Moreover, HA significantly improved tumor targeting capability of DOX-TBH, while ROS based triggering and regenerating mechanism lead to marked inhibition of the tumor growth in the xenograft MCF-7/ADR tumor-bearing nude mice.

Hyaluronic acid/chitosan nanoparticles for delivery of curcuminoid and its in vitro evaluation in glioma cells.

The aim of this work was to evaluate the potential of polyelectrolyte complex nanoparticles (PENPs) based on hyaluronic acid/chitosan (HA/CS) as carriers for water-insoluble curcuminoid (CUR) and explore in vitro performance against brain glioma cells. PENPs were observed to be affected by the order of addition, mass ratios and initial concentrations of the HA/CS, pH and ionic strength. PENPs remained stable over a temperature range of 5–-55(C. CUR was successfully encapsulated into the PENPs. CUR-PENPs showed spherical shape with a mean diameter of 207 nm and positive charge of 25.37 mV. High encapsulation efficiency (89.9%) and drug loading (6.5%) was achieved. Drug release studies revealed initial burst release of drug from the PENPs up to 4h followed by sustained release pattern. DSC thermograms and XRD patterns showed that CUR was encapsulated inside the PENPs in a molecular or amorphous state. Compared with CUR-solution, CUR-PENPs showed stronger dose dependent cytotoxicity against C6 glioma cells and higher performance in uptake efficiency in C6 cells. Cellular uptake of CUR-PENPs was found to be governed by multi-mechanism in C6 cells, involving active endocytosis, macropinocytosis, clathrin-, caveolae-, and CD44-mediated endocytosis. In conclusion, CUR-PENPs might be a promising carrier for therapy of brain gliomas.

Development of brucine-loaded microsphere/thermally responsive hydrogel combination system for intra-articular administration.

Intra-articular drug delivery system could directly deliver a drug to an affected joint and offer the possibility of reaching high drug concentrations at the site of action with limited systemic toxicity. However, depending on their chemical structure, some active compounds were rapidly cleared from the joint, thus requiring numerous injections, which could cause infection or joint disability. To control the release behavior for prolonged time periods, a novel biologically based drug delivery vehicle was designed for intra-articular using microsphere/thermally responsive hydrogel combination system in this paper. And brucine was the test drug. The system was constructed by dispersing the brucine microspheres which was prepared by using a spray-drying method in a thermally responsive biopolymer hydrogel contained with chitosan-glycerol-borax. The microspheres were spherical as evidenced by the scanning electron microscopy (SEM) photographs. And the entrapment rate was 98.60% w/w with an average size range of 0.9-4.5 μm. Fourier transforms infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) revealed the absence of drug-polymer interaction and amorphous nature of an entrapped drug. From the in vitro drug release study we could see that there was a burst release of microsphere, which was obviously retarded when dispersed in hydrogel. And the studies of biocompatibility with synovium showed that no apparent thickening or hyperplasia of the synovium, a small quality of phlogocyte imbibitions was observed. The results of FX imaging in rats showed that by intra-articular injection the BMH could stay in articular for over 7 days were consistent with our in vitro release. And the results of pharmacodynamics revealed the BMH could benefit OA joint by suppressing the levels of TNF-α and IL-1β, protect the damaged joint from degradation. The novel microsphere/thermoresponsive hydrogel combination system could be a promising treatment option for OA and RA. In conclusion, the system appears to be generally biocompatible with synovium and could control the drug release for several days; hence it might be suitable for the development of treatment strategies for rheumatic diseases.

Preparation and Oral Bioavailability Study of Curcuminoid-Loaded Microemulsion

Curcuminoid, a dietary polyphenolic compound, has poor water solubility and low bioavailability following oral administration. The aim of this study was to develop a formulation of curcuminoid-loaded microemulsion (Cur-ME) to improve its oral bioavailability. The optimized Cur-ME formulation was prepared by using labrafac lipophile WL 1349, cremophor RH 40, and glycerine as the oil phase, the surfactant, and the cosurfactant, respectively. Pharmacokinetics and bioavailability of curcuminoid suspension and Cur-ME were evaluated and compared in rats. Plasma bisdemethoxycurcumin (BDMC), treated as the representing component of curcuminoid, was determined by high-performance liquid chromatography with fluorescence detector. After gavage administration of curcuminoid suspension, the plasma BDMC level was very low, below 5 ng/mL, whereas for Cur-ME, double peak of maximum concentrations were observed. The relative bioavailability of Cur-ME was enhanced in an average of 9.6-fold that of curcuminoid suspension. It was concluded that the bioavailbility of curcuminoid was enhanced greatly by the microemulsion.

An arginine derivative contained nanostructure lipid carriers with pH-sensitive membranolytic capability for lysosomolytic anti-cancer drug delivery.

By inserting L-arginine lauril ester (AL) into nanostructure lipid carriers (NLCs) and then coating with bovine serum albumin (BSA), pH-sensitive membranolytic and lysosomolytic nanocarriers (BSA-AL-NLCs) were developed. Hemolysis assay demonstrated the pH-sensitive biomembrane disruptional capability of AL and BSA-AL-NLCs. BSA-AL-NLCs did not disrupt biomembrane at pH 7.4 even at high concentration, exhibited ideal feasibility as lysosomolytic drug delivery nanoparticles without cytotoxicity. Confocal Laser Scanning Microscope (CLSM) images confirmed the lysosomolytic capability of BSA-AL-NLCs after internalized into MCF-7 (human breast cancer cell) via endosome-lysosome path in vitro. Paclitaxel (PTX) loaded BSA-AL-NLCs displayed pH-dependent release in vitro. In MCF-7 viability test with MTT assays, both the blank NLCs did not exhibit cellular toxicity. Of particular interest, the in vitro cell experiments demonstrated that the anti-tumor effect of PTX-loaded BSA-AL-NLCs was preferable to BSA-NLCs, even comparable with PTX solution, which indicated that AL served to facilitate lysosomal escape of BSA-AL-NLCs so as to improve the anti-cancer effect. Biodistribution and anti-cancer activity in vivo confirmed the improved tumor targeting and anti-cancer efficacy of BSA-AL-NLCs. The study suggested that the simple and small molecule of AL may render more nanocarriers lysosomolytic capability with lower cytotoxicity, as well as improved therapeutic index of loaded active agents.