共查询到20条相似文献,搜索用时 46 毫秒
1.
Christian Lubich Peter Allacher Maurus de la Rosa Alexander Bauer Thomas Prenninger Frank Michael Horling Jürgen Siekmann Johannes Oldenburg Friedrich Scheiflinger Birgit Maria Reipert 《Pharmaceutical research》2016,33(9):2239-2249
Purpose
Recent findings demonstrated anti-PEG antibody formation in some healthy individuals and patients who have not received PEGylated biotherapeutics. Some of these findings evoked criticism because of shortcomings in the antibody assays used. To better understand this topic, we established robust antibody analytics and screened two cohorts of healthy individuals and one cohort of hemophilia patients for the expression of anti-PEG antibodies.Methods
A flow cytometry approach and a fully validated ELISA platform were established to detect specific anti-PEG antibodies. Immunohistochemistry was used to test for potential binding of anti-PEG antibodies to human tissues.Results
IgM and/or IgG anti-PEG antibodies are expressed by some healthy individuals and by some patients with hemophilia who have not received PEGylated biotherapeutics. These antibodies can be either transient or persistent and recognize PEGs of different sizes with or without terminal methoxy groups. Age and location of healthy individuals influence the prevalence of IgG but not of IgM antibodies. Anti-PEG antibodies do not cross-react with human tissues supporting the safety of the antibodies.Conclusion
We confirm that some healthy individuals and some patients with hemophilia express specific antibodies against PEG which are not associated with any pathology and do not bind to human tissues.2.
Taro Shimizu Amr S. Abu Lila Mizuki Awata Yukiyo Kubo Yu Mima Yosuke Hashimoto Hidenori Ando Keiichiro Okuhira Yu Ishima Tatsuhiro Ishida 《Pharmaceutical research》2018,35(11):223
Purpose
Immunogenicity of PEGylated proteins and nanomedicines represents a potential impediment against their development and use in clinical settings. The purpose of this study is to develop a method for detecting anti-PEG immunity of PEGylated proteins and/or nanomedicines using flow cytometry.Methods
The binding of fluorescence-labeled mPEG-modified liposomes to HIK-G11 cells, PEG-specific hybridoma cells, or spleen cells was evaluated by flow cytometry for detecting immunogenicity of PEGylated therapeutics.Results
The fluorescence-labeled methoxy PEG (mPEG)-modified liposomes were efficiently bound to HIK-G11 cells. Such staining with fluorescence-labeled mPEG-modified liposomes was significantly inhibited in the presence of either non-labeled mPEG-modified liposomes or mPEG-modified ovalbumin (OVA) but not polyglycerol-modified liposomes. In addition, we found that mPEG-modified liposomes, highly immunogenic, caused proliferation of PEG-specific cells, while hydroxyl PEG-modified liposomes, less immunogenic, scarcely caused. Furthermore, after intravenous injection of mPEG-modified liposomes, the percentage of PEG-specific cells in the splenocytes, as determined by flow cytometry, corresponded well with the production level of anti-PEG antibodies, as determined by ELISA.Conclusions
PEG-specific B cell assay we introduced may become a useful method to detect an anti-PEG immune response against PEGylated therapeutics and clarify the mechanism for anti-PEG immune responses.3.
Roonak Saadati Simin Dadashzadeh Zahra Abbasian Hoorieh Soleimanjahi 《Pharmaceutical research》2013,30(4):985-995
Purpose
To investigate accelerated blood clearance (ABC) induction upon repeated injections of PLGA-PEG nanoparticles as a commonly used polymeric drug carrier.Methods
Etoposide-loaded PLGA-PEG NPs were developed and administered as the test dose to rats pre-injected with various NP treatments at certain time intervals. Pharmacokinetic parameters of etoposide and production of anti-PEG IgM antibody were evaluated.Results
A notable ABC effect was induced by a wide range of polymer doses (0.1 to 20 mg) of empty NPs, accompanied by IgM secretion. However, a further increase in polymer dose resulted not only in the abrogation of the observed ABC induction but also in distinctly a higher value for AUC of the NPs relative to the control. The data from the PEG-negative group verified the fundamental role of PEG for ABC induction. The first injection of etoposide-containing PEGylated nanoparticles (a cell cycle phase-specific drug) produced a strong ABC phenomenon. Three sequential administrations of etoposide-loaded NPs abolished ABC, although a high level of IgM was still detected, which suggests saturation with insignificant poisoning of immune cells.Conclusion
The presented results demonstrate the importance of clinical evaluations for PLGA-PEG nanocarriers that consider the administration schedule in multiple drug delivery, particularly in cancer chemotherapy. 相似文献4.
Tsutomu Ishihara Miho Takeda Haruka Sakamoto Ayumi Kimoto Chisa Kobayashi Naoko Takasaki Kanae Yuki Ken-ichiro Tanaka Mitsuko Takenaga Rie Igarashi Taishi Maeda Naoki Yamakawa Yoshinari Okamoto Masami Otsuka Tatsuhiro Ishida Hiroshi Kiwada Yutaka Mizushima Tohru Mizushima 《Pharmaceutical research》2009,26(10):2270-2279
Purpose
We recently developed prostaglandin E1 (PGE1)-encapsulated nanoparticles, prepared with a poly(lactide) homopolymer (PLA, Mw?=?17,500) and monomethoxy poly(ethyleneglycol)-PLA block copolymer (PEG-PLA) (NP-L20). In this study, we tested whether the accelerated blood clearance (ABC) phenomenon is observed with NP-L20 and other PEG-modified PLA-nanoparticles in rats.Methods
The plasma levels of PGE1 and anti-PEG IgM antibody were determined by EIA and ELISA, respectively.Results
Second injections of NP-L20 were cleared much more rapidly from the circulation than first injections, showing that the ABC phenomenon was induced. This ABC phenomenon, and the accompanying induction of anti-PEG IgM antibody production, was optimal at a time interval of 7 days between the first and second injections. Compared to NP-L20, NP-L33s that were prepared with PLA (Mw?=?28,100) and have a smaller particle size induced production of anti-PEG IgM antibody to a lesser extent. NP-L20 but not NP-L33s gave rise to the ABC phenomenon with a time interval of 14 days. NP-L33s showed a better sustained-release profile of PGE1 than NP-L20.Conclusions
This study revealed that the ABC phenomenon is induced by PEG-modified PLA-nanoparticles. We consider that NP-L33s may be useful clinically for the sustained-release and targeted delivery of PGE1. 相似文献5.
Philippe Pierrat Dimitri Kereselidze Patrick Wehrung Guy Zuber Françoise Pons Luc Lebeau 《Pharmaceutical research》2013,30(5):1362-1379
Purpose
Biolabile cationic lipids were developed for efficient intracellular delivery of DNA and siRNA.Methods
The compounds have been designed starting from the membrane lipid DOPC in a way they may loose their cationic charge when exposed to an acidic and/or enzymatic stimulus, such as those met during the journey of a lipoplex in biological media.Results
They demonstrated remarkable efficiency to deliver DNA in various cell lines (BHK-21, Calu-3, NCI-H292, and A549), with no significant cytotoxicity. Furthermore, two of the compounds (carbonate-based DOPC derivatives) revealed able to deliver small interfering RNA in U87Luc and A549Luc cancer cells and to mediate a selective 70–80% knockdown of the stably transfected luciferase gene.Conclusions
The results show that the described bioresponsive cationic lipids have high DNA and siARN delivery activity which is encouraging in view of delivering a therapeutic nucleic acid to pulmonary tissues in vivo. 相似文献6.
Yongzhong Wang Yunfei Ding Ziming Liu Xingrong Liu Li Chen Weili Yan 《Pharmaceutical research》2013,30(11):2902-2916
Purpose
Construction of a novel PEGylated bioactive lipids-based micelle system for co-delivery of doxorubicin (DOX) and short chain ceramide (C6-ceramide) to overcome multidrug resistance in leukemia.Methods
The PEGylated bioactive lipids-based micelle system was constructed via electrostatic and hydrophobic interactions among DOX, bioactive lipids PazPC and C6-ceramide. The micellar formulation was characterized in terms of size, zeta potential, stability and release behavior, etc., and in vitro cytotoxicity, in vivo antitumor efficacy and the underlying mechanism were further evaluated.Results
This novel micellar system showed small size (~15 nm), high drug encapsulation efficiency (>90%), good stability and endosomal acid-triggered release of DOX. Synergistic cytotoxic effects between DOX and bioactive lipid C6-ceramide in P-gp overexpressing drug resistant leukemia P388/ADR cells were observed. The mechanistic studies demonstrated that modulation of drug efflux system and induction of apoptotic effects by lipids were responsible for the synergistic effects between DOX and C6-ceramide in drug resistant leukemia P388/ADR cells. Using an in-vivo P388/ADR leukemia mouse model, the median survival time of the DOX-loaded PEGylated micelles with PazPC and C6-ceramide as major components was significantly greater than that of free DOX and control group.Conclusions
We developed a novel pH sensitive bioactive lipids-based micellar formulation which could potentially be useful in delivering chemotherapeutic drug DOX and provide a novel strategy to increase the therapeutic index for drug resistant leukemia treatment. 相似文献7.
Generation,characterization and in vivo biological activity of two distinct monoclonal anti-PEG IgMs
Yosuke Hashimoto Taro Shimizu Yu Mima Amr S. Abu Lila Tatsuhiro Ishida Hiroshi Kiwada 《Toxicology and applied pharmacology》2014
PEGylation, the attachment of polyethylene glycol (PEG) to nanocarriers and proteins, is a widely accepted approach to improving the in vivo efficacy of the non-PEGylated products. However, both PEGylated liposomes and PEGylated proteins reportedly trigger the production of specific antibodies, mainly IgM, against the PEG moiety, which possibly leads to a reduction in safety and therapeutic efficacy of the PEGylated products. In the present study, two monoclonal anti-PEG IgMs — HIK-M09 via immunization with an intravenous injection of PEGylated liposomes (SLs) and HIK-M11 via immunization with a subcutaneous administration of PEGylated ovalbumin (PEG-OVA) were successfully generated. The generated IgMs showed efficient reactivity to mPEG2000 conjugated to 1,2-distearoyl-sn-glycero-3-phospho-ethanolamine (DSPE), PEGylated liposome (SL) and PEG-OVA. It appears that HIK-M09 recognizes ethoxy (OCH2CH2) repeat units along with a terminal motif of PEG, while HIK-M11 recognizes only ethoxy repeat units of PEG. Such unique properties allow HIK-M09 to bind with dense PEG. In addition, their impact on the in vivo clearance of the PEGylated products was investigated. It was found that the generated ant-PEG IgMs induced a clearance of SL as they were intravenously administered with SL. Interestingly, the HIK-M11, generated by PEG-OVA, induced the clearance of both SL and PEG-OVA, while the HIK-M09, generated by SL, induced the clearance of SL only. We here revealed that the presence of serum anti-PEG IgM and the subsequent binding of anti-PEG IgM to the PEGylated products are not necessarily related to the enhanced clearance of the products. It appears that subsequent complement activation following anti-PEG IgM binding is the most important step in dictating the in vivo fate of PEGylated products. This study may have implications for the design, development and clinical application of PEGylated products and therapeutics. 相似文献
8.
Purpose
Regulation of gene expression using small interfering RNA (siRNA) is a promising strategy for treatments of numerous diseases. However, the progress towards broad application of siRNA requires the development of safe and effective vectors that target to specific cells. In this study, we developed a novel recombinant high density lipoprotein (rHDL) vector with high siRNA encapsulation efficiency.Methods
They were prepared by condensing siRNA with various commercial cationic polymers and coating the polyplex with a layer of lipids and apolipoprotein AI (apo AI). The rHDL nanoparticles were used to transfect SMMC-7721 hepatoma cells with stable luciferase expression. The uptake and intracellular trafficing of siRNA were also investigated.Results
Characterization studies revealed these rHDL nanoparticles had similar physical properties as natural HDLs. The various rHDL formulations had high silencing efficiency (more than 70% knockdown) in hepatocytes with minimum cytotoxicity. Moreover, the uptake of rHDL by SMMC-7721 was confirmed to be mediated through the natural HDL uptake pathway.Conclusions
The work described here demonstrated the optimized rHDL nanoparticles may offer a promising tool for siRNA delivery to the liver. 相似文献9.
Purpose
Poor stability and inefficient absorption in the intestinal tract are major barriers confronting oral delivery of siRNA. We aimed to uncover if ternary polymeric nanoparticles (cationic polymer/siRNA/anionic component) can overcome these obstacles through changing the formulation-related parameters.Methods
Ternary polymeric nanoparticles were prepared by ionic gelation of chitosan, N-trimethyl chitosan (TMC), or thiolated trimethyl chitosan (TTMC) with tripolyphosphate (TPP) or hyaluronic acid (HA), and siRNA was simultaneously encapsulated. Structural stabilities and siRNA protection of these nanoparticles were assessed in simulated intestinal milieu. Their transport across ex vivo rat ileum, macrophage uptake, in vitro gene silencing, and in vivo biodistribution after oral administration were investigated.Results
Ternary polymeric nanoparticles formed by TTMC, siRNA, and TPP (TTMC/siRNA/TPP nanoparticles) showed suitable structural stability and siRNA protection in the intestinal tract, good permeability across ex vivo rat ileum, superior cellular uptake and gene silencing efficiency in Raw 264.7 cells, and high systemic biodistribution after oral administration.Conclusions
TTMC/siRNA/TPP nanoparticles demonstrated efficient gene silencing in vitro and systemic biodistribution in vivo, therefore, they were expected to be potential vehicles for oral siRNA delivery. 相似文献10.
11.
Purpose
Clinical application of cationic polymers for delivery of nucleic acids has been limited by their toxicity. The purpose of this study is to evaluate whether the polymer-in-lipid hybrid nanotechnology recently developed for controlled siRNA delivery can tackle this toxicity issue by reducing exposure of the cellular components to free cationic polymers.Methods
Lipid-polymer hybrid nanocarriers (LPNs) encapsulating complexes of hexadecylated polyethylenimine (H-PEI) and biologically inactive siRNA in lipids were prepared at different lipid-polymer ratios. Comparative toxicity of these LPNs and unencapsulated cationic materials on breast epithelial cell lines MDA-MB-231 and MCF-10a was evaluated.Results
Even at a low lipid-polymer ratio (3:1 w/w), encapsulation of H-PEI improved its LC50 values measured within hours by 3–5 fold, and caused less reduction in the colony-formation rates in 10–14 days. The observed reductions in the acute and delayed carrier toxicity were associated with significantly less membrane damages, improved mitochondrial functions, reduced reactive oxidative species production, and lower caspase-3 activity (all p?<?0.05) without sacrificing the siRNA transfection efficiency.Conclusions
This study has validated the hybrid nanotechnology for controlled RNA delivery from a toxicological perspective. This is especially valuable if local or long-term RNA therapy is intended for which low carrier toxicity is essential. 相似文献12.
T Shimizu M Ichihara Y Yoshioka T Ishida S Nakagawa H Kiwada 《Biological & pharmaceutical bulletin》2012,35(8):1336-1342
A single intravenous administration of polyethylene glycol-coated (PEGylated) bovine serum albumin (BSA) and ovalbumin (OVA) elicited an anti-PEG immunoglobulin M (IgM) response, similar to that from PEGylated liposomes, although the administration did not elicit specific neutralizing antibodies to BSA and OVA. A cross-reactivity was observed between anti-PEG IgMs elicited by PEG-BSA and PEGylated liposomes. The anti-PEG IgM level induced by PEGylated proteins (BSA and OVA) reached the maximum at day 5 following intravenous injection. This production pattern was consistent with that induced by PEGylated liposomes. Splenectomy suppressed the anti-PEG IgM response against PEG-BSA and PEGylated liposomes. These observations relating PEG-BSA and PEGylated liposomes indicate that PEGylated proteins might promote the immune responses against PEG with a mechanism similar to that of PEGylated liposomes. In addition, a single intravenous administration of PEGylated adenovirus (PEG-Ad) also elicited an anti-PEG IgM response in a PEG-modification ratio dependent manner. To the best of our knowledge, this is the first report showing that an intravenous administration can elicit an anti-PEG IgM response against PEGylated substances. It appears that anti-PEG IgMs can be produced by the systemic administration of a PEGylated substance and may limit the efficacy of PEGylated substances such as proteins, Ad vector and nanoparticles, due to a cross-reactivity seen in some patients. The immunogenicity of PEGylated substances is usually tested against those very substances, rather than against covalently attached PEG. Our study suggests that the PEG immunogenicity of PEGylated therapeutic agents and particles merits further investigation. 相似文献
13.
Purpose
Preparation, optimization and in vitro evaluation of core-shell nanoparticles comprising of a hydrophilic core of BSA surrounded by a hydrophobic shell of PLGA for loading water-soluble drugs.Methods
A double emulsion method was optimized for preparation of BSA-PLGA based core-shell nanoparticles. Proof of concept for core-shell type structure was established by visual techniques like confocal microscopy and TEM. Characterization was done for particle size, encapsulation efficiency, drug loading and in vitro drug release. Cellular uptake was assessed using confocal microscopy, bio-TEM and HPLC assay, and cytotoxic activity was tested by MTT assay in MG-63 osteosarcoma cells.Results
The optimized core-shell nanoparticles showed a particle size of 243 nm (PDI-0.13) and encapsulation efficiency of 40.5% with a drug loading of 8.5% w/w. In vitro drug release studies showed a sustained release for 12 h. Cellular uptake studies indicated a rapid and efficient uptake within 2 h. TEM studies indicated that the core-shell nanoparticles were localized in cytoplasm region of the cells. Gemcitabine loaded core-shell nanoparticles showed enhanced cytotoxicity against MG-63 cells as compared to marketed formulation of gemcitabine (GEMCITE®).Conclusion
These results indicate that core-shell nanoparticles can be a good carrier system for delivering hydrophilic drugs like gemcitabine successfully to the cells with enhanced efficacy.Core-Shell Nanoparticles with a hydrophilic BSA core and hydrophobic PLGA shell for carrier system of hydrophilic drugs 相似文献
14.
Purpose
To apply a combinatorial chemistry approach toward the design of polymeric vectors, and to evaluate their effectiveness as siRNA delivery systems in vitro.Methods
Poly(acrylic acid) (pAA) was synthesized via RAFT polymerization with well-controlled molecular weights (M n: 3 kDa, 5 kDa, 10 kDa and 21 kDa). A polymer library was generated from the pAA precursors by conjugating two distinct moieties, agmatine (Agm) and D-(+)-galactosamine (Gal), at various ratios. Biophysical and cellular characterization was evaluated in vitro for these polymeric vectors using MDA-MB-231-luc+ cells.Results
A critical balance between Agm/Gal content and polymer molecular weight must be attained to achieve favorable transfection efficacies. From the library of 22 polymers, only a few had knockdown efficiencies commensurate with effective siRNA delivery, particularly those with polymer precursor M n of 5 kDa and 10 kDa. Highest protein knockdown of 84% was achieved by a polymer conjugate with a 5 kDa pAA backbone with a side chain composition of 55% Agm and 17% Gal.Conclusions
Effective delivery of siRNA was found to be highly dependent on the molecular structure of the polymeric vector. The combinatorial approach employed provided the tools to identify optimal structural properties leading to efficient siRNA delivery for this class of vector. 相似文献15.
Ryan Gene Soderquist Evan M. Sloane Lisa C. Loram Jacqueline A. Harrison Ellen C. Dengler Scott M. Johnson Luke D. Amer Courtney S. Young Makenzie T. Lewis Stephen Poole Matthew G. Frank Linda R. Watkins Erin D. Milligan Melissa J. Mahoney 《Pharmaceutical research》2010,27(5):841-854
Purpose
Interleukin-10 (IL-10) is an anti-inflammatory molecule that has achieved interest as a therapeutic for neuropathic pain. In this work, the potential of plasmid DNA-encoding IL-10 (pDNA-IL-10) slowly released from biodegradable microparticles to provide long-term pain relief in an animal model of neuropathic pain was investigated.Methods
PLGA microparticles encapsulating pDNA-IL-10 were developed and assessed both in vitro and in vivo.Results
In vitro, pDNA containing microparticles activated macrophages, enhanced the production of nitric oxide, and increased the production of IL-10 protein relative to levels achieved with unencapsulated pDNA-IL-10. In vivo, intrathecally administered microparticles embedded in meningeal tissue, induced phagocytic cell recruitment to the cerebrospinal fluid, and relieved neuropathic pain for greater than 74 days following a single intrathecal administration, a feat not achieved with unencapsulated pDNA. Therapeutic effects of microparticle-delivered pDNA-IL-10 were blocked in the presence of IL-10-neutralizing antibody, and elevated levels of plasmid-derived IL-10 were detected in tissues for a prolonged time period post-injection (>28 days), demonstrating that therapeutic effects are dependent on IL-10 protein production.Conclusions
These studies demonstrate that microparticle encapsulation significantly enhances the potency of intrathecally administered pDNA, which may be extended to treat other disorders that require intrathecal gene therapy. 相似文献16.
Abbasi M Aliabadi HM Moase EH Lavasanifar A Kaur K Lai R Doillon C Uludağ H 《Pharmaceutical research》2011,28(10):2516-2529
Purpose
The efficacy of chemotherapy is decreased due to over-expression of the drug transporter P-glycoprotein (P-gp). This study was conducted to determine the feasibility of down-regulating tumor P-gp levels with non-viral siRNA delivery in order to sensitize the tumors to drug therapy.Methods
P-gp over-expressing MDA435/LCC6 MDR1 cells were used to establish xenografts in NOD-SCID mouse. Cationic polymers polyethylenimine (PEI) and stearic acid-substituted poly-L-lysine (PLL-StA) were formulated with P-gp- specific siRNAs and delivered intratumorally to explore the feasibility of P-gp down-regulation in tumors. Intravenous Doxil? was administered to investigate tumor growth.Results
PEI and PLL-StA effectively delivered siRNA to MDA435/LCC6 MDR1 cells in vitro to reduce P-gp expression for 3 days. Intratumoral injection of siRNA with the carriers resulted in 60-80% and 20?C32% of siRNA retention in tumors after 24 and 96 hr, respectively. This led to ~29.0% and ~61.5% P-gp down-regulation with PEI- and PLL-StA-mediated siRNA delivery, respectively. The P-gp down-regulation by intratumoral siRNA injection led to better response to systemic Doxil? treatment, resulting in slowed tumor growth in originally doxorubicin-resistant tumors.Conclusion
Effective P-gp down-regulation was feasible with polymeric siRNA delivery in a xenograft model, resulting in an enhanced response to the drug therapy. 相似文献17.
Miho Nara Naoto Takahashi Masatomo Miura Takenori Niioka Hideaki Kagaya Naohito Fujishima Hirobumi Saitoh Yoshihiro Kameoka Hiroyuki Tagawa Makoto Hirokawa Kenichi Sawada 《European journal of clinical pharmacology》2013,69(6):1321-1329
Purpose
The purpose of this study was to investigate the interactions of itraconazole (ITCZ) with orally administered calcineurin inhibitors (CNIs) in Japanese allogeneic hematopoietic stem cell transplant (HSCT) recipients.Methods
Sixteen HSCT patients (8 patients each receiving tacrolimus or cyclosporine) were enrolled. An ITCZ oral solution was administered from day 30 after the initiation of ITCZ administration as a loading dose. Before the co-administration of ITCZ and CNI and 1 week daily thereafter, whole blood ITCZ and CNI (tacrolimus or cyclosporine) concentrations were measured in samples taken just before (C0h) and 2 h (C2h) after CNI administration.Results
The median dose-adjusted C0h values of tacrolimus and cyclosporine on day 7 after the start of ITCZ co-administration were 5.6- and 2.7-fold higher, respectively, than the corresponding values obtained before the initiation of ITCZ treatment. On day 7 after ITCZ treatment, the mean single dosages of tacrolimus and cyclosporine were reduced to 33.7 and 66.5 % of the dosages before ITCZ co-administration, respectively, to adjust the CNI target concentration. Although ITCZ co-administration did not alter the dose-adjusted C0h values of tacrolimus in a patient with a CYP3A5*1/*1 allele, it did change this value of tacrolimus in patients with CYP3A5*3 alleles. However, in patients receiving cyclosporine, no such tendency was observed.Conclusion
The magnitude of the interaction between orally administered tacrolimus and ITCZ was significantly greater than that between cyclosporine and ITCZ. Prospective analysis of the CYP3A5 polymorphism may be important to ensure safe and reliable immunosuppressive therapy with tacrolimus in patients treated with ITCZ. 相似文献18.
Purpose
Bioreducible crosslinked polyplexes were prepared via disulfide bond formation after siRNA condensation with polyethylenimine-modified by deoxycholic acid (PEI-DA) to stabilize polyplex structure in an extracellular environment and to promote transfection efficiency in human smooth muscle cells (hSMCs).Methods
The PEI-DA/siRNA polyplexes were further modified by crosslinking the primary amines of PEI with thiol-cleavable crosslinkers. The effect of disulfide crosslinked PEI-DA/siRNA (Cr PEI-DA/siRNA) polyplexes on target gene silencing was investigated by transfecting hSMCs with matrix metalloproteinase-2 (MMP-2) siRNA under serum conditions. The MMP-2 levels in the conditioned medium were examined using gelatin zymography.Results
The Cr PEI-DA/siRNA polyplexes showed increased stability against heparin exchange reactions, while their disulfide linkages were successfully cleaved under reducing conditions. The polyplex crosslinking reaction led to a slight decrease in MMP-2 gene silencing activity in hSMCs due to the insufficient redox potential. However, the gene silencing efficiency of the Cr PEI-DA/siRNA polypexes was gradually improved in response to increasing intracellular reduction potential. The increased serum stability of the Cr PEI-DA/siRNA polyplexes resulted in significant enhancement of the intracellular delivery efficiency especially under serum conditions.Conclusion
The Cr PEI-DA/siRNA polyplex formulation may be a promising siRNA delivery system for the treatment of incurable genetic disorders. 相似文献19.
Linlin Wu Changjun Man Hong Wang Xiaohe Lu Qinghai Ma Yu Cai Wanshan Ma 《Pharmaceutical research》2013,30(2):412-423
Purpose
To develop PEGylated multi-walled carbon nanotubes as a sustained release drug delivery system.Methods
Oxaliplatin was incorporated into inner cavity of PEGylated multi-walled carbon nanotubes (MWCNT-PEG) using nano-extraction. Oxaliplatin release rates from MWCNT-PEG-Oxaliplatin were investigated using dialysis tubing. Cytotoxicity of oxaliplatin, MWCNT-Oxaliplatin and MWCNT-PEG-Oxaliplatin were evaluated in HT29 cell by MTT assay, Pt-DNA adducts formation, γ-H2AX formation and cell apoptosis assay.Results
Loading of oxaliplatin into MWCNT-PEG was ~43.6%. Sustained release occurred to MWCNT-PEG-Oxaliplatin, with only 34% of oxaliplatin released into medium within 6 h. In MTT assay, MWCNT-PEG-Oxaliplatin showed slightly decreased cytotoxic effect when cell viability was assessed at 12 and 24 h. A drastic increase of cytotoxicity was found when cell viability was assessed at 48 and 96 h. Pt-DNA adducts formation, γ-H2AX formation and cell apoptosis assay results showed the same trend as the MTT assay, suggesting sustained-release for MWCNT-Oxaliplatin and MWCNT-PEG-Oxaliplatin formulations.Conclusions
PEGylated multi-walled carbon nanotubes can be used as sustained release drug delivery system, thus remarkably improving cytotoxicity of oxaliplatin on HT-29 cells. 相似文献20.
Kang SH Cho HJ Shim G Lee S Kim SH Choi HG Kim CW Oh YK 《Pharmaceutical research》2011,28(12):3069-3078