The Experts below are selected from a list of 2235 Experts worldwide ranked by ideXlab platform
Jorg Kreuter - One of the best experts on this subject based on the ideXlab platform.
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body distribution of polysorbate 80 and doxorubicin loaded 14c poly Butyl Cyanoacrylate nanoparticles after i v administration in rats
Journal of Drug Targeting, 2005Co-Authors: Alessandra Ambruosi, Hiromitsu Yamamoto, Jorg KreuterAbstract:Previously it was shown that poly(Butyl Cyanoacrylate) (PBCA) nanoparticles coated with polysorbate 80 are able to cross the blood-brain barrier (BBB) after i.v. administration. The objective of the present study was to investigate the influence of polysorbate 80 and doxorubicin-loading on the body distribution in rats. The biodistribution profile and brain concentration of 14C-radiolabeled PBCA nanoparticles, polysorbate 80 coated 14C-PBCA nanoparticles, and doxorubicin-loaded 14C-PBCA nanoparticles were determined by radioactivity counting after i.v. administration in rats. The 14C-PBCA nanoparticles showed a significant accumulation in the organs of the reticuloendothelial system (RES). Polysorbate 80 coating of the 14C-PBCA nanoparticles decreased this accumulation to about 40% after 1 h post injection. The brain concentration was increased about 2-fold after polysorbate 80-coating at this time point. The presence of doxorubicin in this preparation, however, decreased the brain concentration to levels...
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toxicological studies of doxorubicin bound to polysorbate 80 coated poly Butyl Cyanoacrylate nanoparticles in healthy rats and rats with intracranial glioblastoma
Toxicology Letters, 2002Co-Authors: Svetlana Gelperina, A S Khalansky, I N Skidan, Z S Smirnova, A I Bobruskin, S E Severin, B Turowski, F E Zanella, Jorg KreuterAbstract:Abstract Polysorbate 80-coated poly(Butyl Cyanoacrylate) nanoparticles (NP) were shown to enable the transport of a number of drugs including the anti-tumour antibiotic doxorubicin (DOX) across the blood–brain barrier (BBB) to the brain after intravenous administration and to considerably reduce the growth of brain tumours in rats. The objective of the present study was to evaluate the acute toxicity of DOX associated with polysorbate 80-coated NP in healthy rats and to establish a therapeutic dose range for this formulation in rats with intracranially implanted 101/8 glioblastoma. Single intravenous administration of empty poly(Butyl Cyanoacrylate) NP in the dose range 100–400 mg/kg did not cause mortality within the period of observation. NP also did not affect body weight or weight of internal organs. Association of DOX with poly(Butyl Cyanoacrylate) NP did not produce significant changes of quantitative parameters of acute toxicity of the anti-tumour agent. Likewise, the presence of polysorbate 80 in the formulations was not associated with changes in toxicity compared with free or nanoparticulate drug. Dose regimen of 3×1.5 mg/kg on days 2, 5, 8 after tumour implantation did not cause drug-induced mortality. The results in tumour-bearing rats were similar to those in healthy rats. These results demonstrate that the toxicity of DOX bound to NP was similar or even lower than that of free DOX.
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analgesic activity of the hexapeptide dalargin adsorbed on the surface of polysorbate 80 coated poly Butyl Cyanoacrylate nanoparticles
European Journal of Pharmaceutics and Biopharmaceutics, 1995Co-Authors: Renad N Alyautdin, D Gothier, V E Petrov, D A Kharkevich, Jorg KreuterAbstract:Drug targeting to the brain using polysorbate 80-coated nanoparticles was investigated. The leu-enkephalin analogue dalargin was used as a model drug for the investigation of drug penetration through the blood-brain barrier. Nociceptive threshold was measured by means of the tail flick test. Intravenous injection of dalargin bound by sorption to poly(Butyl Cyanoacrylate) nanoparticles that were subsequently coated with polysorbate 80 induced an analgesic effect at doses of 5.0 mg kg -1 and 7.5 mg kg -1 . Pretreatment with naloxone prevented this effect. Other controls, including: a dalargin solution (10 mg kg -1 , i.v.); dalargin bound to nanoparticles without coating with polysorbate 80; and a simple mixture of dalargin, nanoparticles and polysorbate 80 mixed directly before i.v. injection, also exhibited no analgesic activity
Svetlana Gelperina - One of the best experts on this subject based on the ideXlab platform.
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chemotherapy of brain tumour using doxorubicin bound to surfactant coated poly Butyl Cyanoacrylate nanoparticles revisiting the role of surfactants
Journal of Controlled Release, 2007Co-Authors: B Petri, A S Khalansky, A Bootz, Telli Hekmatara, Rainer H Muller, R Uhl, J Kreuter, Svetlana GelperinaAbstract:Abstract Poly(Butyl Cyanoacrylate) nanoparticles coated with poloxamer 188 (Pluronic® F68) and also, as shown previously, polysorbate 80 (Tween® 80) considerably enhance the anti-tumour effect of doxorubicin against an intracranial glioblastoma in rats. The investigation of plasma protein adsorption on the surface of the drug-loaded nanoparticles by two-dimensional electrophoresis (2-D PAGE) revealed that both surfactants, besides other plasma components, induced a considerable adsorption of apolipoprotein A-I (ApoA-I). It is hypothesized that delivery of doxorubicin to the brain by means of nanoparticles may be augmented by the interaction of apolipoprotein A-I that is anchored on the surface of the nanoparticles with the scavenger receptor class B type I (SR-BI) located at the blood–brain barrier. This is the first study that shows a correlation between the adsorption of apolipoprotein A-I on the nanoparticle surface and the delivery of the drug across the blood–brain barrier.
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toxicological studies of doxorubicin bound to polysorbate 80 coated poly Butyl Cyanoacrylate nanoparticles in healthy rats and rats with intracranial glioblastoma
Toxicology Letters, 2002Co-Authors: Svetlana Gelperina, A S Khalansky, I N Skidan, Z S Smirnova, A I Bobruskin, S E Severin, B Turowski, F E Zanella, Jorg KreuterAbstract:Abstract Polysorbate 80-coated poly(Butyl Cyanoacrylate) nanoparticles (NP) were shown to enable the transport of a number of drugs including the anti-tumour antibiotic doxorubicin (DOX) across the blood–brain barrier (BBB) to the brain after intravenous administration and to considerably reduce the growth of brain tumours in rats. The objective of the present study was to evaluate the acute toxicity of DOX associated with polysorbate 80-coated NP in healthy rats and to establish a therapeutic dose range for this formulation in rats with intracranially implanted 101/8 glioblastoma. Single intravenous administration of empty poly(Butyl Cyanoacrylate) NP in the dose range 100–400 mg/kg did not cause mortality within the period of observation. NP also did not affect body weight or weight of internal organs. Association of DOX with poly(Butyl Cyanoacrylate) NP did not produce significant changes of quantitative parameters of acute toxicity of the anti-tumour agent. Likewise, the presence of polysorbate 80 in the formulations was not associated with changes in toxicity compared with free or nanoparticulate drug. Dose regimen of 3×1.5 mg/kg on days 2, 5, 8 after tumour implantation did not cause drug-induced mortality. The results in tumour-bearing rats were similar to those in healthy rats. These results demonstrate that the toxicity of DOX bound to NP was similar or even lower than that of free DOX.
Georgi Yordanov - One of the best experts on this subject based on the ideXlab platform.
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preparation of epirubicin loaded poly Butyl Cyanoacrylate colloidal particles by polymerization in a mixed organic aqueous solvent system
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2013Co-Authors: Zorka Bedzhova, Georgi YordanovAbstract:Abstract This article considers the preparation of poly(Butyl Cyanoacrylate) colloidal drug carriers loaded with the anticancer drug epirubicin by emulsion polymerization in a mixed (acetone/water) solvent system. The use of acetone as a co-solvent allowed better dispersion of the monomer in the polymerization medium and lead to the formation of more uniform nanoparticles. The epirubicin-loaded nanoparticles were prepared in acidic medium containing citric acid and different colloidal stabilizers (dextran 40, poloxamer 188). The obtained nanoparticles were characterized for morphology, size distribution, zeta-potential, drug loading efficiency, drug content, drug release rate and molecular mass distribution. It was found that the nanoparticles prepared in the presence of dextran 40 had the highest drug content, loading efficiency and colloidal stability upon storage at 4 °C as a colloidal dispersion at pH 5.5. The drug loading efficiency was decreasing, while the drug content was increasing with augmentation of the initial drug concentration. The average particle size (~250 nm) did not depend strongly on the drug concentration and was within the ranges suitable for passive tumor targeting. The zeta-potential of drug-loaded nanoparticles was slightly positive in phosphate-buffered saline (pH 7.4) in contrast to the negative zeta-potential of the respective drug-free particles. The molecular mass of polymer in the case of drug-loaded nanoparticles was larger than in the case of drug-free nanoparticles. It is expected that these results should be useful for further successful development of nanoparticle-formulated anthracyclines.
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influence of the preparation method on the physicochemical properties of econazole loaded poly Butyl Cyanoacrylate colloidal nanoparticles
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012Co-Authors: Georgi YordanovAbstract:Abstract This article describes the influence of the preparation method on the physicochemical properties of econazole-loaded poly(Butyl Cyanoacrylate) nanoparticles. The nanoparticles were prepared by using two different methods – nanoprecipitation and emulsion polymerization. Three different non-ionic colloidal stabilizers (poloxamer 188, polysorbate 80 and dextran 40) were used to obtain nanoparticles with various surface coatings. The econazole-loaded nanoparticles were characterized for morphology, size distribution, chemical composition, zeta-potential, drug loading efficiency and drug content. It was found that the average nanoparticle size, yield and drug content depend mainly on the preparation method, while the utilization of different colloidal stabilizers resulted in nanoparticles with different ζ-potentials. The colloidal stability of the formulations was found to depend on the method of preparation, as well as on the type of colloidal stabilizer.
Qineng Ping - One of the best experts on this subject based on the ideXlab platform.
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Preparation, intestinal segment stability, and mucoadhesion properties of novel thymopentin-loaded chitosan derivatives coated with poly (n-Butyl) Cyanoacrylate nanoparticles.
International journal of nanomedicine, 2019Co-Authors: Qi Liu, Qineng Ping, Yun Hong, Xuefeng Jin, Yan Shen, Thomas J. Webster, Yuefeng RaoAbstract:Background In order to develop a promising carrier for the oral delivery of proteins and peptide drugs, a novel bioadhesive nanocarrier of chitosan (CTS) derivatives coated with poly (n-Butyl) Cyanoacrylate nanoparticles (PBCA-NPs) was prepared in this study. Methods Three different thymopentin (TP5)-loaded nanoparticles were prepared in the present study. TP5-PBCA-NPs were developed by modifying an emulsion polymerization method, and CTS and chitosan-glutathione (CG) derivative-coated PBCA nanoparticles were obtained from the electrostatic interactions between CTS or CG with negatively charged PBCA nanoparticles. Results The particle sizes of TP5-PBCA-NPs, TP5-CTS-PBCA-NPs, and TP5-CG-PBCA-NPs were 212.3±6.9, 274.6±8.2, and 310.4±7.5 nm, respectively, while the respective zeta potentials were -22.6±0.76, 23.3±1.2, and 34.6±1.6 mV with encapsulation efficiencies of 79.37%±2.15%, 74.21%±2.13%, and 72.65%±1.48%, respectively. An everted intestinal ring method indicated that drug stability was remarkably improved after incorporation into the nanoparticles, especially the CG-coated nanoparticles. The mucus layer retention rates for CTS- and CG-coated nanoparticles were 1.43 and 1.83 times that of the uncoated nanoparticles, respectively, using ex vivo mucosa. The in vivo mucoadhesion study illustrated that the transfer of uncoated PBCA-NPs from the stomach to the intestine was faster than that of CTS-PBCA-NPs and CG-PBCA-NPs, while the CG-PBCA-NPs presented the best intestinal retentive characteristic. Conclusion In summary, this study demonstrated the feasibility and benefit of orally delivering peptide drugs using novel CTS derivative-coated nanoparticles with optimal stability and bioadhesive properties.
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in vitro and in vivo evaluation of 10 hydroxycamptothecin loaded poly n Butyl Cyanoacrylate nanoparticles prepared by miniemulsion polymerization
Colloids and Surfaces B: Biointerfaces, 2018Co-Authors: Xin Jin, Qineng Ping, Sajid Asghar, Xieting Zhu, Zhipeng Chen, Cihui Tian, Lining Yin, Yanyu XiaoAbstract:Abstract In this paper, 10-hydroxycamptothecin (HCPT)-loaded poly (n-Butyl Cyanoacrylate) nanoparticles (HCPT-PBCA-NPs) co-modified with polysorbate 80, soybean phospholipids, and polyethylene glycol (100) monostearate were successfully prepared via miniemulsion polymerization, and were characterized for particle size, morphology, zeta potential, encapsulation efficiency (EE) and drug loading capacity (DL). The chemical structure of HCPT-PBCA-NPs and the state of HCPT in the PBCA-NPs were investigated by DSC, FTIR and 1H NMR. Additionally, drug release, cytotoxicity, cellular uptake capacity, cellular uptake mechanism, and in vivo behavior of NPs were investigated as well. The particles were 92.7 nm in size with a high EE of 94.24%. FTIR, 1H NMR, and DSC demonstrated complete polymerization of BCA monomers and the drug was in a molecular or amorphous form inside the NPs. In vitro release of the drug from HCPT-PBCA-NPs exhibited sustained-release and less than 60% of HCPT was released from the NPs within 24 h of dialysis. Cellular uptake study displayed that Caco-2 cell uptake of NPs was governed by active endocytosis, clathrin- and caveolin-mediated process, and increased with the increase of the NPs concentration and the time. The pharmacokinetic study in rats showed that encapsulation of HCPT into PBCA-NPs increased the Cmax and AUC0−t about 6.52 and 7.56 times, respectively, in comparison with the HCPT suspension. It was concluded that HCPT loaded PBCA-NPs prepared by miniemulsion polymerization could be promising in oral drug delivery.
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chitosan glutathione conjugate coated poly Butyl Cyanoacrylate nanoparticles promising carriers for oral thymopentin delivery
Carbohydrate Polymers, 2011Co-Authors: Xuefeng Jin, Qineng Ping, Jie Shen, Weiliang YouAbstract:Abstract Thymopentin (TP5)-loaded poly(Butyl Cyanoacrylate) nanoparticles (TP5-PBCA-NPs) were prepared and their efficacies for oral delivery were evaluated before and after coating with chitosan or chitosan–glutathione conjugate (chitosan–GSH). TP5-PBCA-NPs were prepared by using optimized emulsion polymerization. Chitosan–GSH or chitosan was coated onto the surface of TP5-PBCA-NPs utilizing electrostatic interactions. Particle size, zeta potential, entrapment efficiency, TP5 bioactivity and in vitro drug release behavior, were examined. The pharmacodynamical studies on oral administration of these nanoparticles were performed using FACScan flow cytometry. All the drug-loaded nanoparticles increased the CD3+, CD4+ and CD8+ T lymphocytes counts of the immune dysfunction rats compared with the TP5 solution but only chitosan–GSH-coated TP5-PBCA-NPs restored the T lymphocytes level to normal (p
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Box-Behnken optimization design and enhanced oral bioavailability of thymopentin-loaded poly (Butyl Cyanoacrylate) nanoparticles.
Die Pharmazie, 2011Co-Authors: Xuefeng Jin, Qineng Ping, Aiwen Huang, Feng CaoAbstract:This study was done to prepare thymopentin (TP5)-loaded poly (Butyl Cyanoacrylate) nanoparticles (TP5-PBCA-NPs) and evaluate thier efficacy for oral delivery. TP5-PBCA-NPs were prepared by emulsion polymerization, and the formulation was optimized based on Box-Behnken experimental design. The physico-chemical characteristics of TP5-PBCA-NPs were evaluated using transmission electron microscopy (TEM), malvern zetasizer, Fourier transform infra-red spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The encapsulation efficiency, enzymatic degradation and release behavior of TP5-PBCA-NPs in various media were evaluated using a high-performance liquid chromatography (HPLC) method. The pharmacodynamic studies on oral administration of TP5-PBCA-NPs were performed in FACScan flow cytometry. An optimum formulation consisted of 0.7% poloxamer 188 (Pol), 0.6% dextran-70 (Dex), 0.1% sodium metabisulfite (Sm), 0.1% TP5 and 1% (v/v) n-Butyl Cyanoacrylate. The particle size and zeta potential of optimized TP5-PBCA-NPs was 212 nm and -22.6 mV respectively with 82.45% encapsulation efficiency. TP5 was entrapped inside the nanoparticles in molecular dispersion form. The release of TP5 from PBCA-NPs was pH dependent; the cumulative release percentage in 0.1 M HCI for 4 hours was less than 16% while it was more than 80% in pH6.8 PBS. The PBCA-NPs could efficiently protect TP5 from enzymatic degradation; the remained percentage of TP5 encapsulated in PBCA-NPs was 58.40% after incubated with trypsin in pH6.8 PBS for 4 h while it was only 32.29% for free drug. In the oral administration study in vivo, the lowered T-lymphocyte subsets values were significantly increased and the raised CD4+/CD8+ ratio was evidently reduced compared with that of TP5 solution (p < 0.05), and the improvement of bioavailability was dose-dependent. These results indicated that the PBCA nanoparticles may be a promising carrier for oral delivery of TP5.
Alptekin Yasim - One of the best experts on this subject based on the ideXlab platform.
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a randomised clinical trial comparing n Butyl Cyanoacrylate radiofrequency ablation and endovenous laser ablation for the treatment of superficial venous incompetence two year follow up results
European Journal of Vascular and Endovascular Surgery, 2018Co-Authors: Erdinc Eroglu, Alptekin YasimAbstract:Objective To compare early and two year results for N-Butyl Cyanoacrylate (NBCA), radiofrequency ablation (RFA), and endovenous laser ablation (EVLA) in the treatment of varicose veins. Methods This was a randomised clinical trial. Five hundred and twenty five patients were blindly randomised into NBCA, RFA, and EVLT groups (175 patients to each group; block randomisation using sealed envelopes). Four hundred and fifty six patients were monitored for 2 years (ultrasound at 2 days, and 6, 12, and 24 months). The primary endpoint was the saphenous vein occlusion rates, and the secondary endpoints were peri- and post-procedural pain, complications, and time to return to work. No simultaneous phlebectomies were performed. Results The numbers of patients lost to follow up were NBCA seven, RFA 26, and EVLA 36. Occlusion rates were similar at 6, 12, and 24 months (6 months [NBCA 98.1%, RFA 94.1%, and EVLA 95.1%, p = .14], 1 year [NBCA 94.7%, RFA 92.5%, and EVLA 94.2%, p = .72], 2 years [NBCA 92.6%, RFA 90.9%, and EVLA 91.5%, p = .89]). Peri-procedural pain was significantly lower after NBCA (p Conclusion No differences were observed in occlusion rates between the three modalities, but NBCA appeared superior with respect to peri-procedural pain, return to work and decreased VCSS.
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mid term results in the treatment of varicose veins with n Butyl Cyanoacrylate
Phlebology, 2017Co-Authors: Erdinc Eroglu, Alptekin Yasim, Murat Ari, Hasan Cetin Ekerbicer, Aydemir Kocarslan, Mehmet Kabalci, Mehmet AcipayamAbstract:AimTo present mid-term results of patients with varicose veins treated with N-Butyl Cyanoacrylate (VariClose®), a nontumescent endovenous ablation technique.Patients and methodEndovenous ablation was performed on 180 patients with saphenous vein incompetence between May and October 2014. One hundred sixty-eight subjects capable of being followed-up for 30 months were included. Patients’ pre- and postoperative data were recorded.ResultsProcedures were performed on the great saphenous vein in 159 patients and on the small saphenous vein in nine patients. Saphenous vein diameters ranged between 5.5 mm and 14 mm. Full ablation was achieved in all patients following the procedure. No complications were encountered. Patients were monitored for 30 months. Ablation rates were 100% at the 3rd month, 98.3% at the 6th month, 96.6% at 1 year, and 94.1% at 30 months. Mean venous clinical severity score was 10.2 before procedures, decreasing to 3.9 at 3 months, 4.2 at 6 months, 2.9 at 12 months, and 2.7 at 30 months (p...
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a new non tumescent endovenous ablation method for varicose vein treatment early results of n Butyl Cyanoacrylate variclose
Phlebology, 2017Co-Authors: Alptekin Yasim, Erdinc Eroglu, Orhan Bozoglan, Bulent Mese, Mehmet Acipayam, Hakan KaraAbstract:Objective This report aims to present the early results of a retrospective study of the use of N-Butyl Cyanoacrylate (VariClose®)-based non-tumescent endovenous ablation for the treatment of patients with varicose veins. Method One hundred and eighty patients with varicose veins due to incompetent saphenous veins were treated with the VariClose® endovenous ablation method between May 2014 and November 2014. The patient sample consisted of 86 men and 94 women, with a mean age of 47.7 ± 11.7 years. The patients had a great saphenous vein diameter greater than 5.5 mm and a small saphenous vein diameter greater than 4 mm in conjunction with reflux for more than 0.5 s. Patients with varicose veins were evaluated with venous duplex examination, Clinical, Etiological, Anatomical and Pathophysiological classification (CEAP), and their Venous Clinical Severity Scores were recorded. Results The median CEAP score of patients was three, and the saphenous vein diameters were between 5.5 and 14 mm (mean of 7.7 ± 2.1 mm). A percutaneous entry was made under local anesthesia to the great saphenous vein in 169 patients and to the small saphenous vein in 11 patients. Duplex examination immediately after the procedure showed closure of the treated vein in 100% of the treated segment. No complications were observed. The mean follow-up time was 5.5 months (ranging from three to seven months). Recanalization was not observed in any of the patients during follow-up. The average Venous Clinical Severity Scores was 10.2 before the procedure and decreased to 3.9 after three months (p < 0.001). Conclusion The application of N-Butyl Cyanoacrylate (VariClose®) is an effective method for treating varicose veins; it yielded a high endovenous closure rate, with no need for tumescent anesthesia. However, long-term results are currently unknown.
