Yuan Huang

Sichuan University, Hua-yang, Sichuan, China

Are you Yuan Huang?

Claim your profile

Publications (46)139.77 Total impact

  • [Show abstract] [Hide abstract]
    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). · 7.58 Impact Factor
  • [Show abstract] [Hide abstract]
    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. · 8.31 Impact Factor
  • [Show abstract] [Hide abstract]
    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; · 4.79 Impact Factor
  • [Show abstract] [Hide abstract]
    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; · 4.25 Impact Factor
  • [Show abstract] [Hide abstract]
    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. · 8.31 Impact Factor
  • [Show abstract] [Hide abstract]
    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; · 2.20 Impact Factor
  • [Show abstract] [Hide abstract]
    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; · 4.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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; · 4.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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; · 3.99 Impact Factor
  • [Show abstract] [Hide abstract]
    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.
  • [Show abstract] [Hide abstract]
    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; · 2.01 Impact Factor
  • [Show abstract] [Hide abstract]
    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; · 5.26 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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. · 1.00 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study is to develop a duodenum-specific drug delivery system on the basis of a pH-sensitive coating and a mucoadhesive inner core for eradication of Helicobacter pylori (H. pylori) in the ulcer duodenum. Hydroxypropyl methylcellulose acetate maleate (HPMCAM) was used as the pH-sensitive material, which dissolves around pH 3.0. The mucoadhesive microspheres loaded with furazolidone (FZD-ad-MS) were prepared by the emulsification-solvent evaporation method using Carbopol 971NP as the mucoadhesive polymer. The prepared pH-sensitive coated mucoadhesive microspheres (AM-coated-MS) were characterized in regards to particle size, drug loading efficiency, morphological change, drug stability, drug release and in vitro anti-H. pylori activity. The particle size was 160.97 ± 47.24 μm and 336.44 ± 129.34 μm, and the drug content was 42.33 ± 3.43% and 10.96 ± 1.29% for FZD-ad-MS and AM-coated-MS, respectively. The morphological changes in different pH media were characterized by scanning electron microscopy (SEM). HPMCAM coating improved the stability of the FZD-ad-MS and these particles were expected to remain intact until their arrival in the duodenum. The drug release was extremely suppressed at pH 1.2 for AM-coated-MS, but increased at pH 4.0 after regeneration of FZD-ad-MS. In addition, FZD-ad-MS exhibited excellent anti-H. pylori activity in vitro. Thus, the HPMCAM-coated microspheres developed in this study hold great promise for use as a duodenum-specific drug delivery system for H. pylori clearance.
    Archives of Pharmacal Research 05/2012; 35(5):839-50. · 1.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the purpose of increasing incorporation efficiency and improving the release kinetics of plasmid DNA (pDNA) from poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles, a facile method for the fabrication of calcium phosphate (CaPi) embedded PLGA nanoparticles (CaPi-pDNA-PLGA-NPs) was developed. The effect of several preparation factors on the particle size, incorporation efficiency, pDNA release and transfection efficiency in vitro was studied by Single Factor Screening Method. These preparation factors included the molecular weight (MW), hydrolysis degree (HD) of polyvinyl alcohol (PVA), sonication power and time, composition of organic phase, initial concentration of calcium phosphate and calcium (Ca) to phosphate ion (P) ratio (Ca/P ratio), etc. The CaPi-pDNA-PLGA-NPs made according to the optimal formulation were spherical in shape observed by transmission electron microscopy (TEM) with a mean particle size of 207±5 nm and an entrapment efficiency of 95.7±0.8%. Differential scanning calorimetry (DSC) suggested that there existed interaction between the DNA-calcium-phosphate (CaPi-pDNA) complexes and the polymeric matrices of PLGA. X-ray diffractometry (XRD) further proved the conclusion and indicated that the CaPi-pDNA was in weak crystallization form inside the nanoparticles. The Brunauer-Emmett-Teller (BET) surface area measurement demonstrated that the CaPi-pDNA-PLGA-NPs are mesoporous with specific surface area of 57.5m(2)/g and an average pore size of 96.5 Å. The transfection efficiency of the CaPi-pDNA-PLGA-NPs on human embryonic kidney 293 (HEK 293) cells in vitro was 22.4±1.2%, which was much higher than those of both the pDNA loaded PLGA nanoparticles (pDNA-PLGA-NPs) and the CaPi-pDNA embedded PLGA microparticles (CaPi-pDNA-PLGA-MPs). The CaPi-pDNA-PLGA-NPs are promising vectors for gene delivery.
    International Journal of Pharmaceutics 04/2012; 431(1-2):210-21. · 3.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Insufficient gastric mucosa drug concentration and short contact time were the main reason for the lack of eradication efficacy of Helicobacter pylori for peptic ulcer patients. Novel multi-core chitosan microspheres were prepared for stomach-specific delivery of hydrophilic antibiotics for the treatment of peptic ulcer. Chitosan microspheres with multiple Eudragit L100 cores were easily prepared by a new emulsification/coagulation encapsulating method. Swelling behaviors, surface amino groups and mucin absorption ability were investigated and the formulation that showed best mucoadhesive potential was adopted. The multi-core chitosan microspheres exhibited good mucoadhesiveness as well as controlled release manner for incorporated antibiotics in acidic environment. The release rate could be easily modulated with accumulative release ranging from 47.3 to 79.3% in 6 h. Accordingly, the multi-core chitosan microspheres could serve as a satisfactory vehicle for stomach-specific delivery of hydrophilic antibiotics.
    Journal of Materials Science Materials in Medicine 02/2012; 23(4):983-90. · 2.14 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel coated gastric floating drug-delivery system (GFDDS) of bergenin (BN) and cetirizine dihydrochloride (CET) was developed. First, the pharmacodynamic studies were performed and the results revealed that the new compounds of bergenin/cetirizine dihydrochloride had comparative efficacy as commercial products (bergenin/chlorphenamine maleate) but with fewer side effects on central nervous system (CNS). Subsequently, bergenin was formulated as an extended-release core tablet while cetirizine dihydrochloride was incorporated into the gastric coating film for immediate release. The formulation of GFDDS was optimized by CET content uniformity test, in vitro buoyancy and drug release. Herein, the effects of sodium bicarbonate (effervescent), hydroxypropyl methylcellulose (HPMC, matrix polymer) and coating weight gain were investigated respectively. The optimized GFDDS exhibited good floating properties (buoyancy lag time < 2 min; floating duration > 10 h) and satisfactory drug-release profiles (immediate release of CET in 10 min and sustained release of BN for 12 h). In vivo gamma scintigraphy proved that the optimized GFDDS could retain in the stomach with a prolonged gastric retention time (GRT) of 5 h, and the coating layer showed no side effect for gastric retention. The novel coated gastric floating drug-delivery system offers a new approach to enhance BN's absorption at its absorption site and the efficacy of both CET and BN.
    Drug Development and Industrial Pharmacy 12/2011; 38(10):1280-8. · 2.01 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Galectin-3 (Gal-3), over-expressed on a variety of human tumor cells, is a potential binding site for targeted metastatic prostate cancer therapy. The aim of this study was to develop a G3-C12-mediated drug delivery system based on N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers targeting to Gal-3-expressed human PC-3 prostate carcinoma cells. 5-Fluorouracil (5-Fu), an anti-tumor agent, was selected as a model drug. G3-C12, a binding peptide, which specifically binds to the carbohydrate-recognition domain (CRD) of Gal-3, was attached to HPMA copolymers as a targeting moiety. Compared with non-targeted conjugates (P-Fu), Gal-3-targeted HPMA copolymer-(G3-C12)-5-Fu conjugates (P-(G3-C12)-Fu) displayed a superior intracellular internalization followed by enhanced cytotoxicity and apoptosis-induction. Subsequently, the in vitro migration study on PC-3 cells indicated that P-(G3-C12)-Fu was able to efficiently inhibit the cell migration ability after wounding. On PC-3 tumor-bearing mice model, G3-C12-modified copolymers showed a higher tumor accumulation coupled with a faster clearance from blood circulation than non-modified ones. Finally, Gal-3-targeted conjugates significantly improved the anti-tumor activity of 5-Fu in nude mice bearing PC-3 tumor xenografts. Consequently, G3-C12 would be a promising targeting moiety for cell-specific prostate cancer therapy in future.
    Biomaterials 12/2011; 33(7):2260-71. · 8.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study was to demonstrate the effects of goblet cell-targeting nanoparticles on the oral absorption of insulin in vitro, ex vivo and in vivo, and identify the targeting mechanism as well as the influence of mucus. The insulin loaded nanoparticles were prepared using trimethyl chitosan chloride (TMC) modified with a CSKSSDYQC (CSK) targeting peptide. Compared with unmodified nanoparticles, the CSK peptide modification could facilitate the uptake of nanoparticles in villi, enhance the permeation of drugs across the epithelium, meanwhile, induce a significantly higher internalization of drugs via clathrin and caveolae mediated endocytosis on goblet cell-like HT29-MTX cells. In transport studies across Caco-2/HT29-MTX co-cultured cell monolayer (simulating intestinal epithelium), the CSK peptide modification also showed enhanced transport ability, even if the targeting recognition was partially affected by mucus. Moreover, it was found the existence of mucus was propitious to the transport of insulin from both modified and unmodified nanoparticles. In the pharmacological and pharmacokinetic studies in diabetic rats, the orally administrated CSK peptide modified nanoparticles produced a better hypoglycemic effect with a 1.5-fold higher relative bioavailability compared with unmodified ones. In conclusion, CSK peptide modified TMC nanoparticles showed sufficient effectiveness as goblet cell-targeting nanocarriers for oral delivery of insulin.
    Biomaterials 11/2011; 33(5):1573-82. · 8.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In several groups of malignant tumors including head and neck tumors, a protein named Hsp47/CBP2 leaked from the cell was expressed on the tumor cell surface. Several synthetic peptides have been identified as effective ligands for binding to Hsp47/CBP2. This study has focused on the synthesis and in vitro characterization of a targeting delivery system of 5-fluorouracil (5-FU) to human head and neck squamous cell carcinoma (HNSCC) in order to improve anti-cancer efficacy and reduce dose-limiting toxicity of 5-FU. An N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer, with Hsp47/CBP2 binding peptide sequence (namely WHYPWFQNWAMA) as a targeting ligand, was synthesized by a novel and simplified synthetic route. Under the controlled synthetic conditions, 1,3-dimethylol-5-FU, derived from 5-FU, was attached to the HPMA copolymer backbone via the lysosomally degradable GFLG linker, while the WHYPWFQNWAMA was conjugated via a non-degradable Gly-Gly (GG) linker. A control polymer without targeting moiety was also synthesized (P-FU). The in vitro cytotoxicity, internalization and apoptosis assays of the polymeric conjugates were evaluated. The characteristic apoptotic morphological changes were also assessed. Compared to 5-FU and P-FU, the HPMA copolymer containing the Hsp47/CBP2 binding peptide (P-FU-peptide) exhibited the highest cytotoxic efficacy to cell line of human head and neck squamous cell carcinoma (p<0.05) and was internalized much faster than P-FU, especially after being incubated for 30 min. Both of the morphology and apoptosis analyses demonstrated that the treatment of P-FU-peptide resulted in more apoptotic and necrotic induction of tumor cells than P-FU. Meanwhile, the rate of apoptosis induced by P-FU-peptide was higher than that of necrosis. In summary, the HPMA copolymer-Hsp47/CBP2 binding peptide conjugates showed a promising future for the treatment of HNSCC with improved efficacy.
    European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 11/2011; 80(2):379-86. · 3.15 Impact Factor

Publication Stats

303 Citations
139.77 Total Impact Points


  • 2003–2014
    • Sichuan University
      • • Key Laboratory of Drug Targeting and Novel Drug Delivery System
      • • Department of Pharmaceutics
      • • West China School of Pharmacy
      Hua-yang, Sichuan, China