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Liang Y.,Tianjin University | Qiao Y.,Tianjin University | Guo S.,Tianjin University | Wang L.,Tianjin Institute of Medical and Pharmaceutical Science | And 4 more authors.
Soft Matter | Year: 2010

The purpose of this study was to design injectable polymer formulations for controlled release of paclitaxel and Bovine serum albumin (BSA) using amphiphilic triblock copolymer (mPEG-b-P(OA-DLLA)-b-mPEG) consisting of methoxy poly(ethylene glycol) (mPEG), poly(octadecanedioic anhydride) (POA) and d,l-lactic acid oligomer (ODLLA). An aqueous dispersion of mPEG-b-P(OA-DLLA)-b- mPEG nanoparticle freeze-dried powder (NP-FDP) can undergo a sol-gel-sol transition as the temperature is increased from 4 to 90°C. The critical gelation concentration (CGC) and lower critical transition temperature (LCTT) are decreased with the increase of P(OA-DLLA) block length in copolymers. During the in vitro degradation process, the content of mPEG in hydrogels slightly changed after the initial sharp reduction, which makes the average particle size in the degradation liquid increase. In vitro release studies demonstrate that there is no initial burst of drug from both hydrogel formulations containing paclitaxel (1 wt%) and BSA (1 wt%). The in vivo hydrogel formation and biocompatibility results confirm that the copolymer NP hydrogel is biocompatible and non-cytotoxic. Therefore, mPEG-b-P(OA-DLLA)-b-mPEG NP hydrogel is suitable for the controlled release of incorporated drugs for long durations. © 2010 The Royal Society of Chemistry.

Li Y.-W.,Tianjin Medical University | Zhang Y.,Tianjin Huanhu Hospital | Zhang L.,Tianjin Huanhu Hospital | Li X.,Tianjin Institute of Medical and Pharmaceutical Science | And 9 more authors.
Gene | Year: 2014

Tea polyphenols (TP) was investigated in rats for its protective effect on renal ischemia/reperfusion injury (RIRI). Rats were randomized into groups as follows: (I) sham group (n = 10); (II) RIRI group (n = 10); (III) RIRI + TP (100. mg/kg) group (n = 5); (IV) RIRI + TP (200. mg/kg) group (n = 5); (V) RIRI + TP+ Astragalus mongholicus aqueous extract (AMAE) (300. mg/kg + 100. mg/kg) group (n = 5). For the IRI + TP groups, rats were orally given with tea polyphenols (100, 200 and 300. mg/kg body weight) once daily 10. days before induction of ischemia, followed by renal IRI. For the sham group and RIRI group, rats were orally given with equal volume of saline once daily 10. days before induction of ischemia, followed by renal IRI. Results showed that tea polyphenol pretreatment significantly suppressed ROS level and MDA release. On the other hand, in rats subjected to ischemia-reperfusion, the activities of endogenous antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GSH-Px) showed recovery, whereas the levels of urea nitrogen and serum creatinine were reduced by administration of tea polyphenols orally for 10. days prior to ischemia-reperfusion. Moreover, tea polyphenol pretreatment significantly decreased TLR4 and NF-κB p65 protein expression levels in RIRI rats. At the same time, tea polyphenol pretreatment attenuated the increased level of serum IL-1β, IL-6, ICAM-1 and TNF-α, and enhanced IL-10 production in RIRI rats. Furthermore, tea polyphenol pretreatment significantly decreased renal epithelial tubular cell apoptosis induced by renal ischemia/reperfusion, alleviating renal ischemia/reperfusion injury. These results cumulatively indicate that tea polyphenol pretreatment could suppress the TLR4/NF-κB p65 signaling pathway, protecting renal tubular epithelial cells against ischemia/reperfusion-induced apoptosis, which implies that antioxidants may be a potential and effective agent for prevention of the ischemic/reperfusion injury through the suppression extrinsic apoptotic signal pathway induced by TLR4/NF-κB p65 signal pathway. Moreover, supplement of AMAE can increased renal protection effect of TP. © 2014 Elsevier B.V.

Xu S.,Tianjin University | Wang W.,CAS Tianjin Institute of Biomedical Engineering | Li X.,Tianjin Institute of Medical and Pharmaceutical Science | Liu J.,Tianjin University | And 3 more authors.
European Journal of Pharmaceutical Sciences | Year: 2014

As drug therapies become increasingly sophisticated, the synergistic benefits of two or more drugs are often required. In this study, we aimed at improving anti-tumor efficiency of paclitaxel (PTX)-incorporated thermo-sensitive injectable hydrogel by the synergy of burst release of doxorubicin hydrochloride (DOX·HCl). Thermosensitive injectable hydrogel composed of nanoparticles assembled from amphiphilic copolymer poly(ε-caprolactone-co-1,4,8-trioxa[4.6]spiro-9-undecanone)-poly(ethylene glycol)-poly(ε-caprolaone-co-1,4,8-trioxa[4.6]spiro-9-undecanone) (PECT) was fabricated. Hydrophobic PTX and hydrophilic DOX·HCl were loaded simultaneously in the thermo-sensitive injectable hydrogel by a two-stage entrapment. Thermosensitive gelling behaviors of drug-loading PECT nanoparticle aqueous dispersions were studied. In vitro release profiles of PTX and DOX·HCl and in vivo anti-tumor effect by dual drugs from PECT hydrogel were investigated. The results showed that hydrophilic and hydrophobic drugs could be successfully entrapped in PECT hydrogel simultaneously without affecting its thermo-sensitive behavior. In vitro release profiles demonstrated the burst release of DOX·HCl and the sustained release of PTX. Anti-tumor effect was improved by a fast and tense attack caused by the burst release of hydrophilic DOX·HCl from hydrogel, which was continued by the sequent sustained release of PTX-incorporated nanoparticles and remnant DOX·HCl. Unintentionally, entrapped in PECT hydrogel, hydrophilic DOX·HCl was observed to have a sustained releasing pattern in vitro and in vivo. © 2014 Elsevier B.V. All rights reserved.

Wu B.,Nankai University | Zhang H.,China University of Petroleum - East China | Guo P.,Nankai University | Wang Q.,Tianjin Institute of Medical and Pharmaceutical Science | Chang S.,Nankai University
Journal of the Optical Society of America B: Optical Physics | Year: 2010

A multifunctional cross waveguide is designed based on the photonic crystal structure and the liquid crystal material. The different states of the cross waveguide controlled by the electric field make its various functions possible, including a switch with a high extinction ratio, a splitter that divides the terahertz wave into the desired proportions, and a through or 90° turn waveguide. The plane wave expansion method is used to calculate the bandgap in the photonic crystals, and coupling mode theory is adopted to analyze and eliminate the reflection loss. The finite element method is used to get the proper distribution of the external electric field. The properties of the cross waveguide are simulated by the finite difference time domain method, and the results show that the cross waveguide is a multifunctional device with high performance characteristics. © 2010 Optical Society of America.

Chen C.,Tianjin University | Wang L.,Tianjin Institute of Medical and Pharmaceutical Science | Deng L.,Tianjin University | Hu R.,Tianjin Institute of Medical and Pharmaceutical Science | Dong A.,Tianjin University
Journal of Biomedical Materials Research - Part A | Year: 2013

To improve the biocompatibility and application properties of injectable chitosan hydrogel, an injectable triple crosslinking network hydrogel (CTGP) is prepared by physical interaction, Michael addition and disulfide bond formation based on thiolated chitosan (CS-TGA), β-glycerophosphate (β-GP) and poly(ethylene glycol) diacrylate (PEGDA) without the addition of cytotoxic crosslinkers and catalysts. Compared with the short gelation time of 2 min of CTG hydrogel (without PEGDA) at 37°C, CTGP hydrogel containing different molecular weight of PEGDA exhibits controllable gelation times from 1 to 22 min, which could meet the different demands in clinical application. Further, the compressive modulus is improved differently by introducing PEGDA into the system. The presence of PEGDA in CTGP hydrogel imparts better swelling property, and there is a sustained protein release from the hydrogel without any initial burst. In vitro cytotoxicity and hemolysis reveal that the gel is biocompatible. In vivo subdermal injection into mice models further confirms the non-cytotoxicity of the hydrogel and the hydrogel is highly resistant to degradation. © 2012 Wiley Periodicals, Inc.

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