Yuan Huang

Sichuan University, Hua-yang, Sichuan, China

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Publications (53)181.23 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The nucleus is the final target of many first-line chemotherapeutics, but the need to overcome multiple physiological barriers imposes conflicting requirements for size and charge on systemically administered drug delivery systems. Here, an N-(2-hydroxypropyl) methacrylamide (HPMA) polymer-based nanovehicle (PNV) that self-assembles from anionic HPMA copolymers with charge-reversal ability and cationic HPMA copolymers with intracellularly detachable subgroups (IDS) is described. The IDS, bearing an anticancer drug and nuclear-homing cell-penetrating peptide (R8NLS ligand), is grafted onto the HPMA copolymer via hydrazone linkage. The large, neutrally charged, self-assembled PNV (≈55 nm) shows good blood persistence and preferential tumor accumulation. After tumoral arrival, the extracellular milieu actuates the disassembly of PNV to linear conjugates (≈10 nm/39 kDa). This first-stage size reduction exposes R8NLS and allows for deeper tissue penetration and greater cellular internalization. After endocytosis, a second-stage size reduction occurs when the more acidic endolysosomal pH cleaved the ≈2.4 kDa IDS off the HPMA copolymer backbone and guaranteed the successful nuclear entry via nuclear localization signal assistance. Based on the stepwise size reduction and on-demand R8NLS exposure, the PNV inhibits growth of HeLa tumors in nude mice by 75%. This work gives important insights into the design of systemic nuclear-targeted delivery via a multistage size/charge changing way.
    Advanced Functional Materials 05/2015; DOI:10.1002/adfm.201501248 · 10.44 Impact Factor
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    ABSTRACT: The purpose of this study was to formulate nanoparticles with an elaborate structure for oral delivery of exendin-4 using a simple preparation process. The nanoparticles possessed a mixed lipid shell and an aqueous core which contained drug-loaded micelles. Formulation was optimized by a central composite design and the structure of the nanoparticles was validated. The efficacy for delivery of exendin-4 was evaluated both in vitro and in vivo. The drug encapsulation efficiency of the nanoparticles reached 97.7%. The nanoparticles greatly enhanced the cellular uptake and transport of encapsulated exendin-4 in vitro. The in situ study showed that exendin-4 could be transported across the epithelium into intestinal capillaries, while the lipid materials largely remained in the epithelium. Pharmacodynamic studies in diabetic KKAy mice demonstrated that the exendin-4-loaded nanoparticles exhibited a marked hypoglycemia effect with a pharmacological availability of 12.7% after intestinal administration.
    Journal of Biomedical Nanotechnology 05/2015; 11(5). DOI:10.1166/jbn.2015.1971 · 7.58 Impact Factor
  • Zhou Zhou, Xiuli Xu, Lian Li, Yuan Huang
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    ABSTRACT: Non-small cell lung carcinoma is one of the most frequently occurred cancers with a very high rate of recurrence. Self-assembly N-(2-hydroxypropyl) methacrylamide (HPMA) micelles and cross-linked micelles were developed to improve antitumor ability of linear HPMA copolymer. The characters of HPMA micelles were investigated and compared using human non-small cell lung carcinoma 3-D culture model and nude mice xenograft model. Cross-linked micelles showed highest cytotoxicity on A549 cell monolayers after a short time treatment in vitro. Moreover, both of the two micelles exhibited better in vitro anti-tumor activity on A549 tumor spheroids than linear HPMA conjugates especially the cross-linked micelles. On BALB/c nude mice bearing A549 xenograft tumors, the cross-linked micelles exhibited the greatest tumor accumulation and the best anti-tumor activity due to the highly improved stabilities and the more pronounced enhanced permeability and retention (EPR) effect, which were followed by the non-cross-linked micelles. Meanwhile, neither the two micelles nor the linear HPMA copolymers showed significant toxicity on the main organs of mice while free doxorubicin (DOX) showed obvious cardiac toxicity. All the results suggested that micellization improved the anti-tumor activity of HPMA copolymers on A549 human non-small cell lung carcinoma, furthermore, cross-linked HPMA copolymer micelles with pH-sensitivity and biodegradability showed more excellent anti-tumor activity.
    Journal of Drug Targeting 04/2015; DOI:10.3109/1061186X.2015.1025076 · 2.72 Impact Factor
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    ABSTRACT: To improve the therapeutic efficacy of anticancer combination therapy, we designed a nano-platform based on N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers that allows covalent bonding of two chemotherapeutics acting via different anticancer mechanisms and that can enter target cells by receptor-mediated endocytosis. Doxorubicin (DOX) was covalently conjugated to a nano-sized HPMA copolymer using a pH-sensitive hydrazone bond and 5-fluorouracil (5-Fu) was conjugated to the same backbone using an enzymatically degradable oligopeptide Gly-Phe-Leu-Gly sequence. Then the conjugate was decorated with galectin-3 targeting peptide G3-C12 [P-(G3-C12)-DOX-Fu]. The two drugs showed similar in vitro release profiles, suggesting that they may be able to work synergistically in the co-delivery system. In galectin-3 overexpressed PC-3 human prostate carcinoma cells, P-(G3-C12)-DOX-Fu surprisingly exhibited comparable cytotoxicity to free DOX at high concentration by increasing cell internalization and exerting synergistic genotoxic effects of cell cycle arrest, caspase-3 activation and DNA damage. In mice bearing PC-3 tumor xenografts, the use of tumor-targeting ligand substantially enhanced the intracellular delivery of P-(G3-C12)-DOX-Fu in tumors. The targeted dual drug-loaded conjugate inhibited tumor growth to a greater extent (tumor inhibition of 81.6%) than did non-targeted P-DOX-Fu (71.2%), P-DOX (63%), DOX.HCl (40.5%), P-Fu (32.0%) or 5-Fu (14.6%), without inducing any obvious side effects. These results demonstrate the potential of synergistic combination therapy using targeted nanocarriers for efficient treatment of prostate cancer.
    ACS Applied Materials & Interfaces 03/2015; 7(12). DOI:10.1021/am509204u · 5.90 Impact Factor
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    Min Liu, Jian Zhang, Wei Shan, Yuan Huang
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    ABSTRACT: Mucus can effectively protect the exposed mucosal surfaces due to its adhesive and viscoelastic properties. Most foreign particulates are efficiently trapped in mucus layers via steric obstruction and adhesion. Trapped particles are typically removed from the mucosal tissue within seconds to a few hours depending on their location sites. This article focuses on describing the tenacious mucus barrier properties, the strategies to investigate the interaction of nanoparticles with the mucus as well as the novel developments of mucus penetrating nanoparticles.
    Asian Journal of Pharmaceutical Sciences 02/2015; DOI:10.1016/j.ajps.2014.12.007
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    ABSTRACT: Nanoparticles (NPs) have demonstrated great potential for the oral delivery of protein drugs that have very limited oral bioavailability. Orally administered NPs could be absorbed by the epithelial tissue only if they successfully permeated through the mucus that covering the epithelium. However, efficient epithelial absorption and mucus permeation require very different surface properties of a nanocarrier. We herein reported self-assembled NPs for efficient oral delivery of insulin by facilitating both of these two processes. The NPs possessed a nanocomplex core composed of insulin and cell penetrating peptide (CPP), and a dissociable hydrophilic coating of N-(2-hydroxypropyl) methacrylamide copolymer (pHPMA) derivatives. After systematic screening using mucus-secreting epithelial cells, NPs exhibited excellent permeation in mucus due to the "mucus-inert" pHPMA coating, as well as high epithelial absorption mediated by CPP. The investigation of NP behavior showed that the pHPMA molecules graduated dissociated from the NP surface as it permeated through mucus, and the CPP-rich core was revealed in time for subsequent transepithelial transport through the secretory endoplasmic reticulum/Golgi pathway and endocytic recycling pathway. The NPs exhibited 20-fold higher absorption than free insulin on mucus-secreting epithelium cells, and orally administered NPs generated a prominent hypoglycemic response and an increase of the serum insulin concentration in diabetic rats. Our study provided the evidence of using pHPMA as dissociable "mucus-inert" agent to enhance mucus permeation of NPs, and validated a strategy to overcome the multiple absorption barriers using NP platform with dissociable hydrophilic coating and drug-loaded CPP-rich core.
    ACS Nano 02/2015; 9(3). DOI:10.1021/acsnano.5b00028 · 12.03 Impact Factor
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    ABSTRACT: Thanks to the enhanced cancer cell affinity, modification of polymeric drug carriers with an active targeting ligand has been one of the most effective strategies to achieve better therapeutic efficacy. However, hydrophobic ligands (e.g. folate), when conjugated to hydrophilic carriers, encounter the problem of reduced targeting effectiveness due to the fact that the ligand may be buried inside the carrier. In the present study, we studied the impact of the hydrophilic polymer structure on the targeting efficiency of the conjugated folate (FA). After modification with folate, the linear N-(2-hydroxypropyl)-methacrylamide (HPMA) polymer (P-FA, 27.3 kDa) exhibited a neutral surface charge (1.5 mV), while the graft HPMA polymer (GP-FA, 117.4 kDa) possessed a mild negative charge (−7.2 mV), which suggests different exposure levels of negatively charged folate on the surface of P-FA and GP-FA. Notably, on folate receptor positive MCF-7 cells, P-FA exhibited comparable cell uptake with the unmodified linear polymer, whereas GP-FA resulted in 2-fold higher cell internalization over the untargeted graft polymer. Meanwhile, the involvement of folate receptor mediated endocytosis and augmented folate binding affinity of GP-FA were observed in comparison with P-FA. Moreover, GP-FA exhibited significantly enhanced tumor accumulation relative to GP, while marginally improved tumor accumulation was observed for P-FA compared with P. In summary, the structure of the hydrophilic polymer plays a vital role in the targeting efficiency of the conjugated hydrophobic ligand.
    RSC Advances 01/2015; 5(19):14858-14870. DOI:10.1039/C4RA16085A · 3.71 Impact Factor
  • Yuan Huang, Xun Sun
    Molecular Pharmaceutics 10/2014; 11(10):3231-2. DOI:10.1021/mp5005542 · 4.79 Impact Factor
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    ABSTRACT: Increasing the molecular weight of N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers by using micellar structures could result in more pronounced enhanced permeability and retention effect, thus increase the tumor accumulation of drug. However, most micellar formulations are relatively unstable and release their drug non-specifically. To improve on these disadvantages, we developed a micellar drug delivery system based on self-assembly of HPMA copolymers. Amphiphilic conjugates were synthesized by conjugating the hydrophobic drug doxorubicin and hydrophobic β-sitosterol to the hydrophilic HPMA polymer backbone via pH-sensitive hydrazone linkages. This linkage is quite stable at physiological pH but hydrolyzes easily at acidic pH. After conjugates self-assembly into micelles, HPMA copolymer side chains were cross-linked through the hydrazone linkages to ensure micelle stability in the blood. Using this approach, cross-linked micelles were obtained with molecular weight of 1030 KD and diameter of 10–20 nm. These micelles remained stable with undetectable doxorubicin release at pH 7.4 or mouse plasma, whereas collapsed quickly with 80% of the drug released at pH 5 which corresponds to the pH of lyso/endosome compartments of tumor cells. Both cross-linked and non-cross-linked micelles displayed similar in vitro anti-tumor activity as linear copolymer conjugates in Hep G2 and A549 cancer cell lines with internalization mechanism by caveolin, clathrin, and giant macropinocytosis. In vivo studies in an H22 mouse xenograft model of hepatocarcinoma showed the tumor accumulation (1633 μCi/L*h) and anti-tumor rate (71.8%) of cross-linked micelles were significantly higher than non-cross-linked ones (698 μCi/L*h, 64.3%). Neither type of micelle showed significant toxicity in heart, lung, liver, spleen or kidney. These results suggest that cross-linked HPMA copolymer micelles with pH-sensitivity and biodegradability show excellent potential as carriers of anti-cancer drugs.
    Biomaterials 08/2014; 35(24):6622–6635. DOI:10.1016/j.biomaterials.2014.04.059 · 8.31 Impact Factor
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    ABSTRACT: Designing feasible and effective peptide ligand modified solid lipid nanoparticles (SLNs) to improve oral bioavailability of protein drugs and evaluating the influence of mucus remains important. In the present work, two kinds of peptide ligand modified SLNs loaded with salmon calcitonin (sCT), namely, sCT CSK-SLNs and sCT IRQ-SLNs, were prepared by coupling the peptide ligand CSKSSDYQC (CSK) which was reported to show affinity with goblet cells, or IRQRRRR (IRQ), a cell penetrating peptide, to polyoxyethylene (40) stearate (SA-PEG2000). Compared with unmodified SLNs, CSK or IRQ modified SLNs with better drug protection ability could facilitate the internalization of drug on Caco-2/HT29-MTX co-cultured cells and permeation in excised rat duodenum mucosa. The internalization mechanism of two kinds of peptide ligand modified SLNs was mainly active transport via both clathrin- and caveolae-dependent endocytosis. Although mucus was an impediment to the transport of SLNs, the peptide ligand modified SLNs still showed improved drug absorption. The absolute bioavailability of sCT CSK-SLNs (12.41 ± 3.65%) and sCT IRQ-SLNs (10.05 ± 5.10%) raised to 2.45-fold and 1.98-fold compared with unmodified SLNs (5.07 ± 0.54%), implying the feasibility and effectiveness of CSK and IRQ peptide modification for the enhancement of the oral bioavailability of protein drugs. In summary, the nanoparticles modified with CSK or IRQ peptide ligand could be the potential carriers for the transport of protein drugs across intestinal barriers.
    European Journal of Pharmaceutics and Biopharmaceutics 06/2014; 88(2). DOI:10.1016/j.ejpb.2014.06.011 · 4.25 Impact Factor
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    ABSTRACT: Prostate carcinoma is the second leading cause of cancer-related deaths. Increased expression of membrane-bound galectin-3 by prostate carcinoma cell has been found to correlate with more poorly differentiated and increased metastatic potential. In the present study, different amount of galectin-3-binding peptide, G3-C12 (the sequence ANTPCGPYTHDCPVKR), was attached to N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers as targeting moiety. The results of qPCR and competitive binding test indicated that the expression level of galectin-3 in two metastatic prostate carcinoma cell lines (PC-3 and DU145 cells) could be significantly suppressed by the addition of G3-C12-modified HPMA copolymers (PG1 and PG2), demonstrating the high affinity of PG1 and PG2 to galectin-3. Due to the multivalent effects of moieties, the uptake of copolymers was remarkably enhanced with the increasing amount of conjugated G3-C12 peptide. A higher internalization of PG1 and PG2 was occurred in PC-3 cells via caveolin- and clathrin-mediated endocytosis while clathrin-mediated uptake process was involved in DU145 cells. The in vivo biodistribution and pharmacokinetics of non-modified (131I-pHPMA) and G3-C12-modified (131I-PG1 and 131I-PG2) copolymers were estimated on a well-established mice model bearing PC-3 xenografts by 131I-SPECT-imaging. Higher tumor accumulation of 131I-PG1 (1.60 ± 0.08 % ID/g, p<0.05) and 131I-PG2 (1.54 ± 0.06 % ID/g, p<0.05) was observed compared with 131I-pHPMA (1.19 ± 0.04 % ID/g) at 2h post intravenous injection. Although the amount of conjugated G3-C12 peptide performed a remarkable in vitro effect on the affinity and internalization of HPMA copolymers to the galectin-3 over-expressed prostate carcinoma cells, the molecular weight and ligand modification all play important roles on their in vivo tumor accumulation.
    Molecular Pharmaceutics 06/2014; 11(10). DOI:10.1021/mp500083u · 4.79 Impact Factor
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    ABSTRACT: Although folate exhibits many advantages over other targeting ligands, it has one major defect: poor water solubility. Once it was conjugated to hydrophilic drug carrier such as N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer, the hydrophobic folate may be buried inside the random polymer coil and not exposed to be accessible to its receptor on the cell surface, thus losing its active targeting ability. To address this folate dilemma, the positive charge was introduced in the present study. The obtained cationic folate-functionalized HPMA copolymers exhibited a synergistic enhancing effect on cellular uptake by folate receptor (FR) positive Hela cells via electrostatic absorptive endocytosis and folate receptor-mediated endocytosis, with the involvement of multiple internalization pathways including clathrin-mediated endocytosis, caveolae-mediated endocytosis, macropinocytosis and energy-dependent endocytosis. As demonstrated in binding efficiency study, the FR antibody bound to 71.2% of tested cells in the competition with neutral folate modified HPMA copolymers, while the FR antibody-bounded cells decreased to only 34.0% in competition with cationic folate modified HPMA copolymers, indicating that the positively charge could probably amplify the binding efficiency of folate to its receptor due to close proximity of the conjugates to the cell surface by the electronic adhesion. In addition, the cell uptake study on FR negative A549 cells also confirmed the specific role of folate as targeting ligand. Then, to avoid non-specific binding by positive charge in the circulation, the charge shielding/deshielding approach was further employed. With selective hydrolysis of the charge shielding groups 2,3-dimethylmaleic anhydride (DMA) at tumor extracellular pH 6.8, the conjugates underwent a quick charge-reversible process with more than 80% DMA cleavage within 2 h and endocytosed into the endo/lysosomes much more rapidly than at physiological pH 7.4. And then the drug release was triggered by the cleavage of hydrazone spacer at another level of pH 5 in endo/lysosomal compartment. Furthermore, the anticancer activity results showed that Dox-loaded, charge-switchable, folate modified HPMA copolymer conjugates could indeed lead to enhanced cytotoxicity, stronger apoptosis and greater tumor spheroid inhibition towards Hela cells, indicating the great potential feasibility of this multiple responsive drug delivery system.
    Biomaterials 06/2014; 35(19):5171–5187. DOI:10.1016/j.biomaterials.2014.03.027 · 8.31 Impact Factor
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    ABSTRACT: Abstract Somatostatin receptor 2 (SSTR2), specifically over-expressed on many tumor cells, is a potential receipt for active targeting in cancer therapy. In the present study, octreotide (Oct), which had high affinity to SSTR2, was attached to N-(2-hydroxypropyl) methacrylamide (HPMA) polymeric system to enhance the antitumor efficiency of the anticancer drug doxorubicin (DOX). Two kinds of cell lines (HepG2 and A549), which overexpress SSTR2, were chosen as cell models. Compared with non-modified conjugates, Oct-modified conjugates exhibited superior cytotoxicity and intracellular uptake on both HepG2 and A549 cell lines. This might be due to the mechanism of receptor-mediated endocytosis. Subsequently, the in vivo biodistribution and antitumor activity evaluations showed that Oct modification significantly improved the tumor accumulation and antitumor efficacy of HPMA copolymer conjugates in SSTR2 over-expressed Kunming mice bearing H22 tumor xenografts. In summary, Oct-modified HPMA polymer-DOX conjugates might be a promising system for the treatment of SSTR2 over-expressed cancers.
    Drug Delivery 05/2014; DOI:10.3109/10717544.2014.911991 · 2.20 Impact Factor
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    ABSTRACT: Modifying nanoparticles with targeting peptides which can specifically bind to intestinal epithelium was recently suggested as a strategy to further enhance their ability for the oral delivery of macromolecular drugs. However, few studies were focused on comprehensively understanding of the uptake and transport processes as well as the underlying molecular signaling pathways mediated by the ligand modification. In the present study, the mechanisms of cellular uptake and the tight junctions opening associated with the trimethyl chitosan based nanoparticles (M-NPs) and their goblet cell-targeting CSK (CSKSSDYQC) peptide modified nanoparticles (CSK-M-NPs) were investigated. Compared with single ion crosslinked nanoparticles (S NPs), M-NPs and CSK-M-NPs, prepared with multiple agents, exhibited superior stability which could effectively protect drugs against the degradation of trypsin. Caveolae-mediated endocytosis and macropinocytosis were involved in the intracellular uptake of both M-NPs and CSK-M-NPs on Caco-2/HT29-MTX co-cultured cells. However, CSK peptide modification could further induce clathrin-mediated endocytosis of the NPs. Intriguingly, most of endocytosis sub-pathways have been altered after CSK peptide modification. Moreover, the opening of epithelial tight junctions was investigated at both protein and gene levels. The results indicated that both M-NPs and CSK-M-NPs could transiently and reversibly open the epithelial tight junctions via C-Jun NH2-terminal kinase-dependent pathway. However, CSK peptide modification enabled a more rapid opening and recovering of the tight junctions. In all, the enhanced uptake and transport capacity of nanoparticles after CSK peptide modification may be attributed to the alteration of internalization pathways and the stronger ability of opening tight junctions.
    Molecular Pharmaceutics 03/2014; 11(5). DOI:10.1021/mp400685v · 4.79 Impact Factor
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    ABSTRACT: Sufficient mucosal permeability is the bottleneck problem in developing an efficient intestinal delivery system of insulin. Cell penetrating peptide-based nanocomplexes for enhanced mucosal permeation of insulin were developed in this study. Penetratin, a cell penetrating peptide was site-specifically modified with a bis-β-cyclodextrin group. Insulin loaded nanocomplexes were prepared by self-assembly using penetratin or its bis-β-cyclodextrin modified derivative (P-bis-CD). Stronger intermolecular interaction and higher complex stability and were observed for P-bis-CD nanocomplexes than the penetratin nanocomplexes. P-bis-CD nanocomplexes were significantly more efficient for the permeation of insulin as compared to the penetratin nanocomplexes both in vitro and in situ. Interestingly, different cellular internalization mechanisms were observed for the two nanocomplexes. In diabetic rats, intestinal administration of P-bis-CD nanocomplexes resulted in a prominent hypoglycemic effect which lasted for 6h with maximum inhibitory rate at 60 %. Relative pharmacological availability and bioavailability of P-bis-CD nanocomplexes were 10.6% and 7.1%, which were 3.0-fold and 2.3-fold higher than that of penetratin nanocomplexes, respectively. In addition, no sign of toxicity was observed after 7 consecutive days of administration of P-bis-CD nanocomplexes with endotoxin. These results demonstrated that P-bis-CD was a promising epithelium permeation enhancer for insulin and suggested that the chemical modification of cell penetration peptides was a feasible strategy to enhance their potential.
    Molecular Pharmaceutics 11/2013; DOI:10.1021/mp400493b · 4.79 Impact Factor
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    ABSTRACT: The targeting ability of pentapeptide (Thr-Lys-Pro-Pro-Arg) grafted nanostructured lipid carriers (Pen-NLCs) to macrophages was investigated in both in vitro and in vivo studies. The results showed the improvement of the anti-inflammatory effect by using this drug delivery system. Firstly, a pentapeptide-polyethylene glycol2000-stearate was synthesized and formulated into Pen-NLCs. Non-grafted nanostructured lipid carriers (Bare-NLCs) and Pen-NLCs were 190.0±1.0 and 203.0±8.5nm in size, -8.1±2.1 and 2.3±1.2mV in zeta potential respectively. Meanwhile, they had comparable entrapment efficiency and drug loading efficiency. In vitro and in vivo cellular uptake studies showed increased internalization of Pen-NLCs by macrophages when compared to pure drugs and Bare-NLCs. Animal studies in a carrageenan-treated air pouch model were used to further investigate the anti-inflammatory effects of Pen-NLCs. Through intravenous administration, a single dose of DXM loaded Pen-NLCs showed the strongest inhibition of inflammatory indexes of air pouch fluid weight, leukocyte infiltration, granulation tissue weight and nitric oxide concentration in comparison with free drugs and DXM loaded Bare-NLCs. In conclusion, this study demonstrated the potential of Pen-NLCs as promising drug carriers for anti-inflammatory treatments.
    International Journal of Pharmaceutics 04/2013; DOI:10.1016/j.ijpharm.2013.04.030 · 3.79 Impact Factor
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    ABSTRACT: To develop a core-shell structure pDNA-CaPi-PLGA nanoparticles (CS-pDNA-CaPi-PLGA-NPs), calcium phosphate-pDNA nano complexes (CaPi-pDNA) were encapsulated inside of PLGA shells. The characteristics of the nanoparticles, including morphology, average particle size, zeta potential, entrapment efficiency, loading efficiency, stability in medium, pDNA protection ability from nuclease degradation, in vitro release, cytotoxicity and cell transfection were investigated and compared with the embedded structured CaPi modified PLGA nanoparticles (embedded-pDNA-CaPi-PLGA-NPs). The results showed that the obtained CS-pDNA-CaPi-PLGA-NPs were spherical in shape with an average particle size of (155 +/- 4.5) nm, zeta potentials of (-0.38 +/- 0.1) mV, entrapment efficiency of (80.56 +/- 2.5)% and loading efficiency of (1.16 +/- 0.04)%. The CS-pDNA-CaPi-PLGA-NPs were stable in the release media and could protect pDNA against nuclease degradation. And they also exhibited sustained release of pDNA in vitro. The highest gene transfection efficiency of the CS-pDNA-CaPi-PLGA-NPs in vitro reached (24.66 +/- 0.46)% (after 72 h transfection), which was significantly higher than that of free pDNA [(0.33 +/- 0.04)%, P < 0.01] and the pDNA-PLGA-NPs [(1.5 +/- 0.07)%, P < 0.01]. Besides, the transfection lasted for longer time than that of embedded-pDNA-CaPi-PLGA-NPs and the cytotoxicity of it was significantly lower than that of PEI (P < 0.01). These results indicate that CS-pDNA-CaPi-PLGA-NPs are a promising non-viral gene vector. Key words: gene delivery system; polylactic-co-glycolic acid; calcium phosphate; nanoparticle
    Yao xue xue bao = Acta pharmaceutica Sinica 02/2013; 48(2):298-304.
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    ABSTRACT: Abstract Aim: The purpose of this study was to investigate the detailed mechanisms of oral absorption enhancement of bergenin (BN) using BN-phospholipid complex (BPC). Methods: Multiple models such as ex vivo everted rat gut sac model and in vitro Caco-2 cell model were used. Meanwhile, the effect of chitosan on the enhancement of the permeability of BPC was evaluated. Results: The limited absorption of BN was significantly improved in both ex vivo everted rat gut sac model and in vitro Caco-2 cell model when combined with phospholipid. The transport of BPC was uppermost 5.19-fold higher than that of BN. The results of ex vivo everted rat gut sac model showed that small intestine was a more suitable site for the absorption of BN and BPC than colon. Passive diffusion was the only way employed in the transport of BN, while BPC could transport across enterocytes by both passive diffusion and active transport which was found to be the clathrine-dependent receptor-mediated endocytosis. The absorption of BN was barely improved by the physical mixture of BN and phospholipid due to lack of stable intermolecular interactions. Moreover, the addition of chitosan could open the tight junctions of intestinal epithelial cells, thus significantly increasing the transport of BPC via paracellular route. Conclusions: Totally different mechanisms, which led to the enhanced oral bioavailability, were utilized in the uptake and transport process of BPC compared with BN. These results would be of significance for the future development of oral delivery systems of BN.
    Drug Development and Industrial Pharmacy 01/2013; DOI:10.3109/03639045.2012.752500 · 2.01 Impact Factor
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    ABSTRACT: Aim: The purpose of this study was to develop a new orally delivered nanoparticulate system to improve the bioavailability of salmon calcitionin (sCT). Materials & methods: Four sCT-loaded solid lipid nanoparticles (SLNs) were prepared successfully by micelle-double emulsion technique via either the sole use of stearic acid (SA) or the combined use of SA and triglycerides (including tripalmitin [TP], trimyristin or trilaurin). Results: Compared with other SLNs, the combination of SA and TP could not only significantly improve the colloidal stability of SLNs and enhance the drug stability in the simulated intestinal fluids, but also intensively increase the intracellular uptake of drugs compared with the other SLNs (p < 0.05). The mechanism of internalization was an active transport involved in clathrin- and caveolae-dependent endocytosis. In vivo, the sCT SLNs prepared with SA and TP exhibited the highest reduction of plasma Ca(2+) level (17.44 ± 3.68%) with a bioavailability of 13.01 ± 3.24%. Conclusion: The SLNs formed by SA and TP as the solid lipids may be a promising carrier for oral delivery of peptide drugs. Original submitted 1 February 2012; Revised submitted 10 August 2012.
    Nanomedicine 10/2012; DOI:10.2217/nnm.12.141 · 5.82 Impact Factor
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    ABSTRACT: The objective of the present study was to investigate the storage stability of thymopentin multivesicular liposomes (TP5-MVLs) prepared with different emulsifiers, and to study the pharmacokinetics and pharmacodynamics of the produced TP5-MVLs in vivo. The stability studies of TP5-MVLs indicated that MVLs particles prepared with mixed emulsifiers (Myrj52:solutolHS15 = 2:3) were stable at the storage temperature of 4 +/- 2 degrees C within 3 months. In addition, FITC-TP5-loaded MVLs was prepared for pharmacokinetic studies that after subcutaneous administration, the fluorescence signal lasted for about 5 days in plasma demonstrating that the rate of drug release from MVLs was very slow. The pharmacodynamic studies indicated that the therapeutic efficacy of TP5-MVLs after subcutaneous administration once every four days was the same as free TP5 solution after intravenous or subcutaneous administration once daily. In conclusion, MVLs, which possessed great storage stability, can be utilized to reduce the administration frequency of TP5, and therefore, served as a promising sustained release delivery system for polypeptide.
    Pharmazie 06/2012; 67(6):507-12. DOI:10.1691/ph.2012.1126 · 1.00 Impact Factor

Publication Stats

417 Citations
181.23 Total Impact Points

Institutions

  • 2003–2015
    • Sichuan University
      • • Key Laboratory of Drug Targeting and Novel Drug Delivery System
      • • Department of Pharmaceutics
      • • West China School of Pharmacy
      Hua-yang, Sichuan, China