Cette étude a été soutenue par l&#39;Alliance du National Cancer Institute en nanotechnologie pour le Cancer Center pour l&#39;excellence nanotechnologie et le cancer (CCNE) accorder U54 CA151881-.

<ol>
	<li>Vimalachandran, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetics+and+prevention+of+pancreatic+cancer.">Genetics and prevention of pancreatic cancer.</a> Cancer. Control. 11, 6-14 (2004).</li><li>Kommareddy, S., Amiji, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+and+evaluation+of+thiol-modified+gelatin+nanoparticles+for+intracellular+DNA+delivery+in+response+to+glutathione.">Preparation and evaluation of thiol-modified gelatin nanoparticles for intracellular DNA delivery in response to glutathione.</a> Bioconjug. Chem. 16, 1423-1432 (2005).</li><li>Kommareddy, S., Amiji, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly(ethylene+glycol)-modified+thiolated+gelatin+nanoparticles+for+glutathione-responsive+intracellular+DNA+delivery.">Poly(ethylene glycol)-modified thiolated gelatin nanoparticles for glutathione-responsive intracellular DNA delivery.</a> Nanomedicine. 3, 32-42 (2007).</li><li>Kommareddy, S., Amiji, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antiangiogenic+gene+therapy+with+systemically+administered+sFlt-1+plasmid+DNA+in+engineered+gelatin-based+nanovectors.">Antiangiogenic gene therapy with systemically administered sFlt-1 plasmid DNA in engineered gelatin-based nanovectors.</a> Cancer. Gene. Ther. 14, 488-498 (2007).</li><li>Kommareddy, S., Amiji, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biodistribution+and+pharmacokinetic+analysis+of+long-circulating+thiolated+gelatin+nanoparticles+following+systemic+administration+in+breast+cancer-bearing+mice.">Biodistribution and pharmacokinetic analysis of long-circulating thiolated gelatin nanoparticles following systemic administration in breast cancer-bearing mice.</a> J. Pharm. Sci. 96, 397-407 (2007).</li><li>Kaul, G., Amiji, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor-targeted+gene+delivery+using+poly(ethylene+glycol)-modified+gelatin+nanoparticles:+in+vitro+and+in+vivo+studies.">Tumor-targeted gene delivery using poly(ethylene glycol)-modified gelatin nanoparticles: in vitro and in vivo studies.</a> Pharm. Res. 22, 951-961 (2005).</li><li>Bardeesy, N., DePinho, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pancreatic+cancer+biology+and+genetics.">Pancreatic cancer biology and genetics.</a> Nat. Rev. Cancer. 2, 897-909 (2002).</li><li>Li, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+characterization+of+a+novel+peptide+ligand+of+epidermal+growth+factor+receptor+for+targeted+delivery+of+therapeutics.">Identification and characterization of a novel peptide ligand of epidermal growth factor receptor for targeted delivery of therapeutics.</a> FASEB. J. 19, 1978-1985 (2005).</li><li>McCormick, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cancer+gene+therapy:+fringe+or+cutting+edge.">Cancer gene therapy: fringe or cutting edge.</a> Nat. Rev. Cancer. 1, 130-141 (2001).</li><li>Green, D. R., Kroemer, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytoplasmic+functions+of+the+tumour+suppressor+p53.">Cytoplasmic functions of the tumour suppressor p53.</a> Nature. 458, 1127-1130 (2009).</li><li>Barton, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Abnormalities+of+the+p53+tumour+suppressor+gene+in+human+pancreatic+cancer.">Abnormalities of the p53 tumour suppressor gene in human pancreatic cancer.</a> Br. J. Cancer. 64, 1076-1082 (1991).</li></ol>

Pas de conflits d&#39;intérêt déclarés.

Contrôle et EGFR ciblées thiolé nanoparticules de gélatine ont été préparées avec l&#39;ADN d&#39;encapsulation efficace et la stabilité. Les tailles de particules de tous ces systèmes ont été dans la gamme de 150-250 nm de diamètre. Potentiel Zeta a prouvé que ce système est un système légèrement négative. Avec l&#39;analyse MEB, la taille des nanoparticules ont été les mêmes avec un résultat Zetasizer. Analyse ESCA pourrait confirmer PEG et de modification de surface des peptides. Western blot analyse a montré que les cellules Panc-1 a eu un niveau élevé d&#39;expression de l&#39;EGFR et cette lignée cellulaire a été utilisé pour les études in vitro. Tant le contrôle et les nanoparticules à surface modifiée ont été relativement moins cytotoxiques dans les cellules Panc-1 par rapport au PEI. Des études ont montré le trafic cellulaire absorption rapide et la libération de l&#39;EGFR plasmidique ciblée des nanoparticules dans Panc-1 des cellules. Livraison de la journaliste plasmides d&#39;ADN exprimant l&#39;EGFR ciblée des nanoparticules conduit à plus hauts niveaux deExpression de la GFP par rapport à d&#39;autres contrôles, y compris les Lipofectin complexé ADN. Avec le même système, la transfection avec WT-p53 plasmidique a déclenché la voie aval apoptotiques et l&#39;apoptose induite rapide de Panc-1 des cellules. Ces résultats préliminaires suggèrent que l&#39;EGFR ciblées thiolé nanoparticules de gélatine peut servir de système de livraison ADN sûr et efficace pour la thérapie génique comme traitement pour le cancer du pancréas.

<table border="1"><tbody><tr><td> Nom du réactif </td><td> Société </td><td> Numéro de catalogue </td><td> Commentaires </td></tr><tr><td> Gélatine de type B, 225 Bloom </td><td> Sigma-Aldrich </td><td> G9391 </td><td></td></tr><tr><td> 2-iminothiolane chlorhydrate </td><td> Sigma-Aldrich </td><td> I6256 </td><td></td></tr><tr><td> pEGFP-N1 plasmidique </td><td> Elim Biopharm </td><td> N / A </td><td></td></tr><tr><td> pORF-hp53 E. coli </td><td> Invivogen </td><td> porf-hp53 </td><td></td></tr><tr><td> Solution de glyoxal (40wt.% en H 2 O) </td><td> Sigma-Aldrich </td><td> 128465 </td><td></td></tr><tr><td> Glycine </td><td> Sigma-Aldrich </td><td> 410225-250G </td><td></td></tr><tr><td> QIA filtre Plasmid Mega kit </td><td> Qiagen </td><td> 12281 </td><td></td></tr><tr><td> Beckman LE 80K Ultracentrifuger </td><td> Beckman </td><td> N / A </td><td></td></tr><tr><td> Console FreeZone 6 litres Gel systèmes secs </td><td> Labconco </td><td> 7753020 </td><td></td></tr><tr><td> mPEG-SCM, MW 2000 Da </td><td> Laysan </td><td> mPEG-SMC-2K-1g </td><td></td></tr><tr><td> MAL-PEG-SCM, MW 2000 Da </td><td> Jenkem technologie </td><td> A5001-1 </td><td></td></tr><tr><td> Zetasizer Nano </td><td> Malvern </td><td> Zetasizer Nano ZS </td><td></td></tr><tr><td> Émission de champ Hitachi 4800 microscope électronique à balayage </td><td> Hitachi </td><td> S-4800 FE-SEM UHR </td><td></td></tr><tr><td> Quant-iT PicoGreen Réactif ADNdb et kits </td><td> Invitrogen </td><td> P7589 </td><td></td></tr><tr><td> Réactif de transfection Lipofectin </td><td> Invitrogen </td><td> 18292011 </td><td></td></tr><tr><td> DMEM </td><td> Mediatech Cellgro </td><td> 10 013 CM </td><td></td></tr><tr><td> RPMI </td><td> Mediatech Cellgro </td><td> 50 020 PB </td><td></td></tr><tr><td> Pierce BCA Protein Assay Kit </td><td> Thermo Scientific </td><td> 23225 </td><td></td></tr><tr><td> iBlot Système sec Blotting </td><td> Invitrogen </td><td> IB1001 </td><td></td></tr><tr><td> XCell SureLock Mini-Cell et XCell II Blot Module Kit marquage CE </td><td> Invitrogen </td><td> EI0002 </td><td></td></tr><tr><td> Pierce ECL Western Blot Substrat </td><td> Thermo Scientific </td><td> 32109 </td><td></td></tr><tr><td> Kodak Digital rayons X de l&#39;échantillon (DXS) Système </td><td> Kodak </td><td> N / A </td><td>; </td></tr><tr><td> CellTiter AQ 96 ueous Un test de prolifération cellulaire Solution (MTS) </td><td> Promega </td><td> G3580 </td><td></td></tr><tr><td> BioTek SynergyHT lecteur de plaque </td><td> BioTek </td><td> N / A </td><td></td></tr><tr><td> Nanodrop 2000 </td><td> Thermo Scientific </td><td> N / A </td><td></td></tr><tr><td> One-step RT-PCR kit </td><td> Qiagen </td><td> 210212 </td><td></td></tr><tr><td> Condensation de la chromatine / Membrane de perméabilité / Dead Kit apoptose des cellules </td><td> Invitrogen </td><td> V23201 </td><td></td></tr><tr><td> Apo-ONE homogène Caspase-3 / 7 Assay Kit </td><td> Promega </td><td> G7790 </td><td></td></tr><tr><td> Hybaid PCR Sprint Thermocycleur </td><td> Thermo Scientific </td><td> N / A </td><td></td></tr><tr><td> Anticorps anti-récepteur EGF </td><td> Cellulairede signalisation </td><td> 2232 </td><td></td></tr><tr><td> β-actine Anticorps </td><td> La signalisation cellulaire </td><td> 4967 </td><td></td></tr><tr><td> IgG anti-lapin, HRP-anticorps liés </td><td> La signalisation cellulaire </td><td> 7074 </td><td></td></tr><tr><td> Anticorps monoclonal de souris GFP </td><td> Novus Biologicals </td><td> NB600-597 </td><td></td></tr><tr><td> D&#39;anticorps polyclonaux de chèvre GFP (phosphatase alcaline) </td><td> Novus Biologicals </td><td> NB600-1502 </td><td></td></tr><tr><td> Kit substrat de la phosphatase </td><td> Thermo Scientific </td><td> 37620 </td><td></td></tr></tbody></table>

therapeutic gene delivery and transfection in human pancreatic cancer cells using epidermal growth factor receptor-targeted gelatin nanoparticles

Plus de 32.000 patients sont diagnostiqués avec un cancer du pancréas aux Etats-Unis par an et la maladie est associée à une mortalité très élevée 1. Il est urgent de développer de nouvelles cliniquement traduisible stratégies thérapeutiques qui peuvent améliorer les statistiques de survie lamentable des malades du cancer du pancréas. Bien que la thérapie génique dans le cancer a montré une énorme promesse, le défi majeur réside dans le développement du système de prestation sûre et efficace, qui peut conduire à l&#39;expression du transgène soutenue. La gélatine est un des biopolymères les plus polyvalents naturelles, largement utilisé dans les produits alimentaires et pharmaceutiques. Des études antérieures de notre laboratoire ont montré que gélatine de type B pourrait physiques encapsuler l&#39;ADN, qui a conservé la structure superenroulé de l&#39;efficacité de la transfection plasmidique et amélioré lors de la livraison intracellulaire. Par thiolation de gélatine, les groupes sulfhydryle pourraient être introduits dans le polymère et serait fpont disulfure ORM au sein de nanoparticules, ce qui stabilise la liaison disulfure ensemble complexe et une fois est rompu en raison de la présence de glutathion dans le cytosol, la charge utile serait libéré 2-5. Poly (éthylène glycol) (PEG) modifiés SREG, lorsqu&#39;il est administré dans la circulation systémique, permet la circulation à long temps et cible préférentiellement à la masse tumorale en raison de l&#39;hyper-perméabilité de la néovascularisation de la perméabilité accrue et 6 effet de rétention. Des études ont montré une sur-expression du récepteur du facteur de croissance épidermique (EGFR) sur Panc-1 des cellules d&#39;adénocarcinome du pancréas 7. Afin de cibler activement lignée cellulaire du cancer du pancréas, l&#39;EGFR a été conjugué peptidique spécifique sur la surface de la particule par une entretoise PEG 8. La plupart des thérapies géniques anti-tumorale sont axés sur l&#39;administration des gènes suppresseurs de tumeurs, tels que p53 sauvage (WT-p53), pour restaurer la fonction pro-apoptotique dans les cellules 9 </sup&gt;. Le mécanisme fonctionne p53 comme un moyen essentiel de signalisation dans la croissance cellulaire, qui régule l&#39;apoptose, arrêt du cycle cellulaire, le métabolisme et d&#39;autres processus 10. Dans le cancer du pancréas, la plupart des cellules ont des mutations dans la protéine p53, causant la perte d&#39;activité apoptotique. Avec l&#39;introduction des poids-p53, l&#39;apoptose pourrait être réparé et déclenche la mort cellulaire dans d&#39;autres 11 cellules cancéreuses. Basé sur le raisonnement ci-dessus, nous avons conçu EGFR peptide modifié thiolé nanoparticules de gélatine pour la livraison du gène p53 et poids-efficacité de la prestation évaluée et la transfection de cellules Panc-1.

Watch this Scientific Journal Video about Therapeutic Gene Delivery and Transfection in Human Pancreatic Cancer Cells using Epidermal Growth Factor Receptor-targeted Gelatin Nanoparticles at JoVE.com

Therapeutic Gene Delivery and Transfection in Human Pancreatic Cancer Cells using Epidermal Growth Factor Receptor-targeted Gelatin Nanoparticles

Type B à base de gélatine système machiné nanovecteurs (SREG) a été développé pour la livraison de gènes systémiques et la transfection dans le traitement du cancer du pancréas. Par modification des récepteurs du facteur de croissance épidermique (EGFR) peptide spécifique sur la surface de nanparticles, ils pourraient cibler le récepteur EGFR et la libération plasmide sous réduisant l&#39;environnement, tels que de fortes concentrations de glutathion intracellulaire.

Livraison de gènes et transfection de cellules humaines de cancer du pancréas en utilisant facteur de croissance épidermique ciblant les récepteurs des base de gélatine nanovecteurs Conçu

More than 32,000 patients are diagnosed with pancreatic cancer in the United States per year and the disease is associated with very high mortality 1. ...

therapeutic-gene-delivery-transfection-human-pancreatic-cancer-cells

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Bioengineering

27.9K vues.  Northeastern University. Type B à base de gélatine système machiné nanovecteurs (SREG) a été développé pour la livraison de gènes systémiques et la transfection dans le traitement du cancer du pancréas. Par modification des récepteurs du facteur de croissance épidermique (EGFR) peptide spécifique sur la surface de nanparticles, ils pourraient cibler le récepteur EGFR et la libération plasmide sous réduisant l'environnement, tels que de fortes concentrations de glutathion intr...

Vidéo: Therapeutic Gene Delivery and Transfection in Human Pancreatic Cancer Cells using Epidermal Growth Factor Receptor-targeted Gelatin Nanoparticles

Evaluation of Polymeric Gene Delivery Nanoparticles by Nanoparticle Tracking Analysis and High-throughput Flow Cytometry

Non-viral gene delivery using polymeric nanoparticles has emerged as an attractive approach for gene therapy to treat genetic diseases1 and as a technology for regenerative medicine2. Unlike viruses, which have significant safety issues, polymeric nanoparticles can be designed to be non-toxic, non-immunogenic, non-mutagenic, easier to synthesize, chemically versatile, capable of carrying larger nucleic acid cargo and biodegradable and/or environmentally responsive. Cationic polymers self-assemble with negatively charged DNA via electrostatic interaction to form complexes on the order of 100 nm that are commonly termed polymeric nanoparticles. Examples of biomaterials used to form nanoscale polycationic gene delivery nanoparticles include polylysine, polyphosphoesters, poly(amidoamines)s and polyethylenimine (PEI), which is a non-degradable off-the-shelf cationic polymer commonly used for nucleic acid delivery1,3 . Poly(beta-amino ester)s (PBAEs) are a newer class of cationic polymers4 that are hydrolytically degradable5,6 and have been shown to be effective at gene delivery to hard-to-transfect cell types such as human retinal endothelial cells (HRECs)7, mouse mammary epithelial cells8, human brain cancer cells9 and macrovascular (human umbilical vein, HUVECs) endothelial cells10.
A new protocol to characterize polymeric nanoparticles utilizing nanoparticle tracking analysis (NTA) is described. In this approach, both the particle size distribution and the distribution of the number of plasmids per particle are obtained11. In addition, a high-throughput 96-well plate transfection assay for rapid screening of the transfection efficacy of polymeric nanoparticles is presented. In this protocol, poly(beta-amino ester)s (PBAEs) are used as model polymers and human retinal endothelial cells (HRECs) are used as model human cells. This protocol can be easily adapted to evaluate any polymeric nanoparticle and any cell type of interest in a multi-well plate format.

A protocol for nanoparticle tracking analysis (NTA) and high-throughput flow cytometry to evaluate polymeric gene delivery nanoparticles is described. NTA is utilized to characterize the nanoparticle particle size distribution and the plasmid per particle distribution. High-throughput flow cytometry enables quantitative transfection efficacy evaluation for a library of gene delivery biomaterials.

Évaluation de livraison Gene polymère nanoparticules d&#39;analyse de suivi par des nanoparticules et de cytométrie en flux à haut débit

Non-viral gene delivery using polymeric nanoparticles has emerged as an attractive approach for gene therapy to treat genetic diseases1 and as a ...

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Bio-ingénierie

Transplantation of Induced Pluripotent Stem Cell-derived Mesoangioblast-like Myogenic Progenitors in Mouse Models of Muscle Regeneration

Patient-derived iPSCs could be an invaluable source of cells for future autologous cell therapy protocols. iPSC-derived myogenic stem/progenitor cells similar to pericyte-derived mesoangioblasts (iPSC-derived mesoangioblast-like stem/progenitor cells: IDEMs) can be established from iPSCs generated from patients affected by different forms of muscular dystrophy. Patient-specific IDEMs can be genetically corrected with different strategies (e.g. lentiviral vectors, human artificial chromosomes) and enhanced in their myogenic differentiation potential upon overexpression of the myogenesis regulator MyoD. This myogenic potential is then assessed in vitro with specific differentiation assays and analyzed by immunofluorescence. The regenerative potential of IDEMs is further evaluated in vivo, upon intramuscular and intra-arterial transplantation in two representative mouse models displaying acute and chronic muscle regeneration. The contribution of IDEMs to the host skeletal muscle is then confirmed by different functional tests in transplanted mice. In particular, the amelioration of the motor capacity of the animals is studied with treadmill tests. Cell engraftment and differentiation are then assessed by a number of histological and immunofluorescence assays on transplanted muscles. Overall, this paper describes the assays and tools currently utilized to evaluate the differentiation capacity of IDEMs, focusing on the transplantation methods and subsequent outcome measures to analyze the efficacy of cell transplantation.

Induced pluripotent stem cell (iPSC)-derived myogenic progenitors are promising candidates for cell therapy strategies to treat muscular dystrophies. This protocol describes transplantation and functional measurements required to evaluate the engraftment and differentiation of iPSC-derived mesoangioblasts (a type of muscle progenitors) in mouse models of acute and chronic muscle regeneration.

Transplantation de progéniteurs myoangioblastes dérivés de cellules souches pluripotentes induites dans des modèles murins de régénération musculaire

Patient-derived iPSCs could be an invaluable source of cells for future autologous cell therapy protocols. iPSC-derived myogenic stem/progenitor cells ...

Programming Stem Cells for Therapeutic Angiogenesis Using Biodegradable Polymeric Nanoparticles

Controlled vascular growth is critical for successful tissue regeneration and wound healing, as well as for treating ischemic diseases such as stroke, heart attack or peripheral arterial diseases. Direct delivery of angiogenic growth factors has the potential to stimulate new blood vessel growth, but is often associated with limitations such as lack of targeting and short half-life in vivo. Gene therapy offers an alternative approach by delivering genes encoding angiogenic factors, but often requires using virus, and is limited by safety concerns. Here we describe a recently developed strategy for stimulating vascular growth by programming stem cells to overexpress angiogenic factors in situ using biodegradable polymeric nanoparticles. Specifically our strategy utilized stem cells as delivery vehicles by taking advantage of their ability to migrate toward ischemic tissues in vivo. Using the optimized polymeric vectors, adipose-derived stem cells were modified to overexpress an angiogenic gene encoding vascular endothelial growth factor (VEGF). We described the processes for polymer synthesis, nanoparticle formation, transfecting stem cells in vitro, as well as methods for validating the efficacy of VEGF-expressing stem cells for promoting angiogenesis in a murine hindlimb ischemia model.

We describe the method of programming stem cells to overexpress therapeutic factors for angiogenesis using biodegradable polymeric nanoparticles. Processes described include polymer synthesis, transfecting adipose-derived stem cells in vitro, and validating the efficacy of programmed stem cells to promote angiogenesis in a murine hindlimb ischemia model.

Les cellules souches de programmation pour angiogenèse thérapeutique utilisant polymère biodégradable nanoparticules

Controlled vascular growth is critical for successful tissue regeneration and wound healing, as well as for treating ischemic diseases such as stroke, ...

Electrospinning Growth Factor Releasing Microspheres into Fibrous Scaffolds

This procedure describes a method to fabricate a multifaceted substrate to direct nerve cell growth. This system incorporates mechanical, topographical, adhesive and chemical signals. Mechanical properties are controlled by the type of material used to fabricate the electrospun fibers. In this protocol we use 30% methacrylated Hyaluronic Acid (HA), which has a tensile modulus of ~500 Pa, to produce a soft fibrous scaffold. Electrospinning on to a rotating mandrel produces aligned fibers to create a topographical cue. Adhesion is achieved by coating the scaffold with fibronectin. The primary challenge addressed herein is providing a chemical signal throughout the depth of the scaffold for extended periods. This procedure describes fabricating&#160;poly(lactic-co-glycolic acid) (PLGA) microspheres that contain Nerve Growth Factor (NGF) and directly impregnating the scaffold with these microspheres during the electrospinning process. Due to the harsh production environment, including high sheer forces and electrical charges, protein viability is measured after production. The system provides protein release for over 60 days and has been shown to promote primary nerve cell growth.

This protocol combines electrospinning and microspheres to develop tissue engineered scaffolds to direct neurons. Nerve growth factor was encapsulated within PLGA microspheres and electrospun into Hyaluronic Acid (HA) fibrous scaffolds. The protein bioactivity was tested by seeding the scaffolds with primary chick Dorsal Root Ganglia and culturing for 4-6 days.

Électrofilage facteur de croissance libération de microsphères en fibre échafaudages

This procedure describes a method to fabricate a multifaceted substrate to direct nerve cell growth.  This system incorporates mechanical, topographical, ...

Studying the Stoichiometry of Epidermal Growth Factor Receptor in Intact Cells using Correlative Microscopy

This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative fluorescence microscopy and environmental scanning electron microscopy (ESEM) of whole cells in hydrated state. Fluorescent quantum dots (QDs) were coupled to EGFR via a two-step labeling protocol, providing an efficient and specific protein labeling, while avoiding label-induced clustering of the receptor. Fluorescence microscopy provided overview images of the cellular locations of the EGFR. The scanning transmission electron microscopy (STEM) detector was used to detect the QD labels with nanoscale resolution. The resulting correlative images provide data of the cellular EGFR distribution, and the stoichiometry at the single molecular level in the natural context of the hydrated intact cell. ESEM-STEM images revealed the receptor to be present as monomer, as homodimer, and in small clusters. Labeling with two different QDs, i.e.,&#160;one emitting at 655 nm and at 800 revealed similar characteristic results.

This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative light- and electron microscopy of whole cells in hydrated state. The label contained fluorescent quantum dots. The protocol can be used to study the stoichiometry of EGFR at the single molecule level.

L&#39;étude de la Stœchiométrie Epidermal Growth Factor Receptor dans des cellules intactes en utilisant la microscopie corrélative

This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative fluorescence ...

Delivery of Therapeutic siRNA to the CNS Using Cationic and Anionic Liposomes

Prion diseases result from the misfolding of the normal, cellular prion protein (PrPC) to an abnormal protease resistant isomer called PrPRes. The emergence of prion diseases in wildlife populations and their increasing threat to human health has led to increased efforts to find a treatment for these diseases. Recent studies have found numerous anti-prion compounds that can either inhibit the infectious PrPRes isomer or down regulate the normal cellular prion protein. However, most of these compounds do not cross the blood brain barrier to effectively inhibit PrPRes formation in brain tissue, do not specifically target neuronal PrPC, and are often too toxic to use in animal or human subjects. 
We investigated whether siRNA delivered intravascularly and targeted towards neuronal PrPC is a safer and more effective anti-prion compound. This report outlines a protocol to produce two siRNA liposomal delivery vehicles, and to package and deliver PrP siRNA to neuronal cells. The two liposomal delivery vehicles are 1) complexed-siRNA liposome formulation using cationic liposomes (LSPCs), and 2) encapsulated-siRNA liposome formulation using cationic or anionic liposomes (PALETS). For the LSPCs, negatively charged siRNA is electrostatically bound to the cationic liposome. A positively charged peptide (RVG-9r [rabies virus glycoprotein]) is added to the complex, which specifically targets the liposome-siRNA-peptide complexes (LSPCs) across the blood brain barrier (BBB) to acetylcholine expressing neurons in the central nervous system (CNS). For the PALETS (peptide addressed liposome encapsulated therapeutic siRNA), the cationic and anionic lipids were rehydrated by the PrP siRNA. This procedure results in encapsulation of the siRNA within the cationic or anionic liposomes. Again, the RVG-9r neuropeptide was bound to the liposomes to target the siRNA/liposome complexes to the CNS. Using these formulations, we have successfully delivered PrP siRNA to AchR-expressing neurons, and decreased the PrPC expression of neurons in the CNS.

The goal of this protocol is to use cationic/anionic liposomes with a neuro-targeting peptide as a CNS delivery system to enable siRNA to cross the BBB. The optimization of a delivery system for treatments, like siRNA, would allow for more treatment options for prion and other neurodegenerative diseases.

Livraison de siRNA thérapeutique du SNC Utilisation cationique et anionique Liposomes

Prion diseases result from the misfolding of the normal, cellular prion protein (PrPC) to an abnormal protease resistant isomer called PrPRes.  The ...

Polyelectrolyte Complex for Heparin Binding Domain Osteogenic Growth Factor Delivery

During reconstructive bone surgeries, supraphysiological amounts of growth factors are empirically loaded onto scaffolds to promote successful bone fusion. Large doses of highly potent biological agents are required due to growth factor instability as a result of rapid enzymatic degradation as well as carrier inefficiencies in localizing sufficient amounts of growth factor at implant sites. Hence, strategies that prolong the stability of growth factors such as BMP-2/NELL-1, and control their release could actually lower their efficacious dose and thus reduce the need for larger doses during future bone regeneration surgeries. This in turn will reduce side effects and growth factor costs. Self-assembled PECs have been fabricated to provide better control of BMP-2/NELL-1 delivery via heparin binding and further potentiate growth factor bioactivity by enhancing in vivo stability. Here we illustrate the simplicity of PEC fabrication which aids in the delivery of a variety of growth factors during reconstructive bone surgeries.

Self-assembled polyelectrolyte complexes (PEC) fabricated from heparin and protamine were deposited on alginate beads to entrap and regulate the release of osteogenic growth factors. This delivery strategy enables a 20-fold reduction of BMP-2 dose in spinal fusion applications. This article illustrates the benefits and fabrication of PECs.

Complexe de polyélectrolyte pour Heparin Binding Domain Growth Factor ostéogénique Livraison

During reconstructive bone surgeries, supraphysiological amounts of growth factors are empirically loaded onto scaffolds to promote successful bone ...

Manufacture and Drug Delivery Applications of Silk Nanoparticles

Silk is a promising biopolymer for biomedical and pharmaceutical applications due to its outstanding mechanical properties, biocompatibility and biodegradability, as well its ability to protect and subsequently release its payload in response to a trigger. While silk can be formulated into various material formats, silk nanoparticles are emerging as promising drug delivery systems. Therefore, this article covers the procedures for reverse engineering silk cocoons to yield a regenerated silk solution that can be used to generate stable silk nanoparticles. These nanoparticles are subsequently characterized, drug loaded and explored as a potential anticancer drug delivery system. Briefly, silk cocoons are reverse engineered first by degumming the cocoons, followed by silk dissolution and clean up, to yield an aqueous silk solution. Next, the regenerated silk solution is subjected to nanoprecipitation to yield silk nanoparticles &#8211; a simple but powerful method that generates uniform nanoparticles. The silk nanoparticles are characterized according to their size, zeta potential, morphology and stability in aqueous media, as well as their ability to entrap a chemotherapeutic payload and kill human breast cancer cells. Overall, the described methodology yields uniform silk nanoparticles that can be readily explored for a myriad of applications, including their use as a potential nanomedicine.

Nanoparticles are emerging as promising drug delivery systems for a broad range of indications. Here, we describe a simple yet powerful method to manufacture silk nanoparticles using reverse engineered Bombyx mori silk. These silk nanoparticles can be readily loaded with a therapeutic payload and subsequently explored for drug delivery applications.

Fabrication and Drug Delivery Applications de soie Nanoparticules

Silk is a promising biopolymer for biomedical and pharmaceutical applications due to its outstanding mechanical properties, biocompatibility and ...

Preparation and Characterization of Novel HDL-mimicking Nanoparticles for Nerve Growth Factor Encapsulation

The objective of this article is to introduce preparation and characterization methods for nerve growth factor (NGF)-loaded, high-density, lipoprotein (HDL)-mimicking nanoparticles (NPs). HDLs are endogenous NPs and have been explored as vehicles for the delivery of therapeutic agents. Various methods have been developed to prepare HDL-mimicking NPs. However, they are generally complicated, time consuming, and difficult for industrial scale-up. In this study, one-step homogenization was used to mix the excipients and form the prototype NPs. NGF is a water-soluble protein of 26 kDa. To facilitate the encapsulation of NGF into the lipid environment of HDL-mimicking NPs, protamine USP was used to form an ion-pair complex with NGF to neutralize the charges on the NGF surface. The NGF/protamine complex was then introduced into the prototype NPs. Apolipoprotein A-I was finally coated on the surface of the NPs. NGF HDL-mimicking NPs showed preferable properties in terms of particle size, size distribution, entrapment efficiency, in vitro release, bioactivity, and biodistribution. With the careful design and exploration of homogenization in HDL-mimicking NPs, the procedure was greatly simplified, and the NPs were made scalable. Moreover, various challenges, such as separating unloaded NGF from the NPs, conducting reliable in vitro release studies, and measuring the bioactivity of the NPs, were overcome.

Simple homogenization was used to prepare novel, high-density, lipoprotein-mimicking nanoparticles to encapsulate nerve growth factor. Challenges, detailed protocols for nanoparticle preparation, in vitro characterization, and in vivo studies are described in this article.

Préparation et caractérisation de nouvelles nanoparticules imitant HDL pour l&#39;encapsulation du facteur de croissance nerveuse

The objective of this article is to introduce preparation and characterization methods for nerve growth factor (NGF)-loaded, high-density, lipoprotein ...

Human Neural Organoids for Studying Brain Cancer and Neurodegenerative Diseases

The lack of relevant in vitro neural models is an important obstacle on medical progress for neuropathologies. Establishment of relevant cellular models is crucial both to better understand the pathological mechanisms of these diseases and identify new therapeutic targets and strategies. To be pertinent, an in vitro model must reproduce the pathological features of a human disease. However, in the context of neurodegenerative disease, a relevant in vitro model should provide neural cell replacement as a valuable therapeutic opportunity. 
Such a model would not only allow screening of therapeutic molecules but also can be used to optimize neural protocol differentiation [for example, in the context of transplantation in Parkinson's disease (PD)]. This study describes two in vitro protocols of 1) human glioblastoma development within a human neural organoids (NO) and 2) neuron dopaminergic (DA) differentiation generating a three-dimensional (3D) organoid. For this purpose, a well-standardized protocol was established that allows the production of size-calibrated neurospheres derived from human embryonic stem cell (hESC) differentiation. The first model can be used to reveal molecular and cellular events occurring during in glioblastoma development within the neural organoid, while the DA organoid not only represents a suitable source of DA neurons for cell therapy in Parkinson's disease but also can be used for drug testing.

This study introduces and describes protocols to derive two specific human neural organoids&#160;as a relevant and accurate model for studying 1) human glioblastoma development within human neural organoids exclusively in humans and 2) neuron dopaminergic differentiation generating a three-dimensional organoid.

Organoïdes neuronaux humains pour étudier le cancer du cerveau et les maladies neurodégénératives

The lack of relevant in vitro neural models is an important obstacle on medical progress for neuropathologies. Establishment of relevant cellular models ...