Este estudio fue apoyado por la Alianza del Instituto Nacional del Cáncer en el Centro de Nanotecnología para el Cáncer para el cáncer Nanotecnología Excelencia (CCNE) de subvención 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>

No hay conflictos de interés declarado.

Control y EGFR dirigidos nanopartículas de gelatina tiolada se prepararon con la encapsulación de ADN eficiente y la estabilidad. El tamaño de las partículas de todos estos sistemas estaban en el rango de 150-250 nm de diámetro. El potencial zeta se ha demostrado que este sistema es un sistema un poco negativo. Con el análisis SEM, el tamaño de las nanopartículas eran los mismos con el resultado de Zetasizer. Análisis ESCA pudo confirmar PEG y modificación de la superficie de péptidos. Western blot mostraron que células Panc-1 tenía una alta expresión los niveles de EGFR y esta línea celular se utilizó para los estudios in vitro. Tanto el control y las nanopartículas de superficie modificada eran relativamente menos citotóxico en células Panc-1 en comparación con el PEI. Estudios de células tráfico mostró una rápida aceptación y la liberación del plásmido de EGFR nanopartículas en células Panc-1. La entrega de la reportera de ADN con plásmidos que expresan EGFR nanopartículas resultó en niveles más altos deLas buenas prácticas agrarias en relación con otros controles, incluyendo un complejo de ADN-Lipofectina expresión. Con el mismo sistema, la transfección con el plásmido wt-p53 activa la vía apoptótica aguas abajo y la apoptosis inducida rápido en células Panc-1. Estos resultados preliminares sugieren que el EGFR nanopartículas de gelatina tiolada puede servir como un sistema de ADN parto seguro y eficaz para la terapia génica como tratamiento para el cáncer de páncreas.

<table border="1">
<tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments </td>
 </tr>
 <tr>
 <td>Type B gelatin, Bloom 225</td>
 <td>Sigma-Aldrich</td>
 <td>G9391</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>2-iminothiolane hydrochloride</td>
 <td>Sigma-Aldrich</td>
 <td>I6256</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>pEGFP-N1 plasmid</td>
 <td>Elim Biopharm</td>
 <td>N/A</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>pORF-hp53 E. coli</td>
 <td>Invivogen</td>
 <td>porf-hp53 </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Glyoxal solution (40wt. % in H2O) </td>
 <td>Sigma-Aldrich</td>
 <td>128465</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Glycine</td>
 <td>Sigma-Aldrich</td>
 <td>410225-250G </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>QIA filter Plasmid Mega kit</td>
 <td>Qiagen</td>
 <td>12281 </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Beckman LE 80K Ultracentrifuge</td>
 <td>Beckman</td>
 <td>N/A</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>FreeZone 6 Liter Console Freeze Dry Systems</td>
 <td>Labconco</td>
 <td>7753020 </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>mPEG-SCM, MW 2,000 Da </td>
 <td>Laysan</td>
 <td>mPEG-SCM-2K-1g </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>MAL-PEG-SCM, MW 2,000 Da </td>
 <td>Jenkem Technology</td>
 <td>A5001-1 </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Zetasizer Nano</td>
 <td>Malvern</td>
 <td>Zetasizer Nano ZS </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Hitachi 4800 field emission scanning electron microscope</td>
 <td>Hitachi</td>
 <td>S-4800 UHR FE-SEM </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Quant-iT PicoGreen 
 dsDNA Reagent and Kits </td>
 <td>Invitrogen</td>
 <td>P7589 </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Lipofectin Transfection Reagent</td>
 <td>Invitrogen</td>
 <td>18292011 </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>DMEM</td>
 <td>Mediatech cellgro</td>
 <td>10 013 CM </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>RPMI</td>
 <td>Mediatech cellgro</td>
 <td>50 020 PB </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Pierce BCA Protein Assay Kit</td>
 <td>Thermo Scientific</td>
 <td>23225</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>iBlot Dry Blotting System</td>
 <td>Invitrogen</td>
 <td>IB1001</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>XCell&nbsp;SureLock Mini-Cell and XCell II Blot Module Kit CE Mark</td>
 <td>Invitrogen</td>
 <td>EI0002 </td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Pierce ECL Western Blotting Substrate </td>
 <td>Thermo Scientific</td>
 <td>32109</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Kodak Digital X-ray Specimen (DXS) System </td>
 <td>Kodak</td>
 <td>N/A</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>CellTiter 96 AQueous One Solution Cell Proliferation Assay (MTS)</td>
 <td>Promega</td>
 <td>G3580</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>BioTek SynergyHT plate reader</td>
 <td>BioTek</td>
 <td>N/A</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Nanodrop 2000</td>
 <td>Thermo Scientific</td>
 <td>N/A</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>One-step RT-PCR kit</td>
 <td>Qiagen</td>
 <td>210212</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Chromatin Condensation/Membrane Permeability/Dead Cell Apoptosis Kit </td>
 <td>Invitrogen</td>
 <td>V23201</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Apo-ONE Homogeneous Caspase-3/7 Assay kit</td>
 <td>Promega</td>
 <td>G7790</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Hybaid PCR Sprint Thermal Cycler</td>
 <td>Thermo Scientific</td>
 <td>N/A</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>EGF Receptor Antibody </td>
 <td>Cell signaling</td>
 <td>2232</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>&beta;-Actin Antibody </td>
 <td>Cell signaling</td>
 <td>4967</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Anti-rabbit IgG, HRP-linked Antibody </td>
 <td>Cell signaling</td>
 <td>7074</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Mouse Monoclonal GFP Antibody</td>
 <td>Novus Biologicals</td>
 <td>NB600-597</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Goat Polyclonal GFP antibody (Alkaline Phosphatase)</td>
 <td>Novus Biologicals</td>
 <td>NB600-1502</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Phosphatase Substrate Kit</td>
 <td>Thermo Scientific</td>
 <td>37620</td>
 <td>&nbsp;</td>
 </tr>
 </tbody>
</table>

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

Más de 32.000 pacientes son diagnosticados con cáncer de páncreas en los Estados Unidos por año y la enfermedad se asocia con una mortalidad muy alta 1. Existe la urgente necesidad de desarrollar nuevas estrategias terapéuticas clínicamente traducible que pueden mejorar en las estadísticas de supervivencia triste de pacientes con cáncer de páncreas. Aunque la terapia génica en el cáncer ha demostrado una gran promesa, el gran reto es el desarrollo del sistema de suministro seguro y eficaz, que puede conducir a la expresión del transgén sostenido. La gelatina es una de las biopolímero natural más versátil, ampliamente utilizado en productos alimenticios y farmacéuticos. Estudios anteriores de nuestro laboratorio han demostrado que el tipo B de gelatina podría física encapsular ADN, que conserva la estructura superenrollado de la eficacia de transfección de plásmidos y la mejora en la entrega intracelular. Por tiolación de gelatina, los grupos sulfhidrilo pueden introducirse en el polímero y se fbonos orm disulfuro dentro de las nanopartículas, que estabiliza el enlace disulfuro todo el complejo y una vez que se ha roto debido a la presencia de glutatión en el citosol, la carga útil sería liberado 2-5. Poli (etilenglicol) (PEG)-modificada GENS, cuando se administra en la circulación sistémica, permite la circulación de largo tiempo y se dirige preferentemente a la masa tumoral, debido a la hiper-permeabilidad de la vasculatura por el aumento de la permeabilidad y el efecto de retención de 6. Los estudios han demostrado la sobre-expresión del receptor del factor de crecimiento epidérmico (EGFR) en Panc-1 las células humanas de adenocarcinoma pancreático 7. A fin de combatir activamente el cáncer de páncreas líneas celulares, el péptido específico de EGFR se conjugó en la superficie de la partícula a través de un espaciador PEG 8. La mayoría de las terapias anti-tumorales de genes se centran en la administración de los genes supresores de tumores, como el p53 de tipo salvaje (wt-p53), para restaurar la función pro-apoptótica en las células de 9 </sup&gt;. El mecanismo funciona p53 como una vía fundamental de señalización en el crecimiento celular, que regula la apoptosis, la detención del ciclo celular, el metabolismo y otros procesos 10. En el cáncer de páncreas, la mayoría de las células con mutaciones en la proteína p53, que causa la pérdida de actividad de apoptosis. Con la introducción del peso de p53, la apoptosis puede ser reparado y además desencadena la muerte celular en células de cáncer 11. Con base en los fundamentos anteriores, hemos diseñado EGFR objetivo péptido modificado con nanopartículas de gelatina tiolada para la entrega del gen p53 en peso y la eficiencia de la entrega y evaluación de transfección en células 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

Tipo B a base de gelatina sistema nanovectors ingeniería (gens) fue desarrollado para la entrega de genes sistémicos y transfección en el tratamiento del cáncer de páncreas. Por la modificación con el receptor de factor de crecimiento epidérmico (EGFR) péptido específico en la superficie de nanparticles, podrían dirigir a los receptores EGFR y la liberación del plásmido en la reducción de medio ambiente, tales como altas concentraciones de glutatión intracelular.

Entrega y transfección de genes en células humanas de cáncer de páncreas con factor de crecimiento epidérmico receptor dirigidos a base de gelatina Nanovectors Ingeniería

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

Research

JoVE Journal

Bioengineering

27.9K vistas.  Northeastern University. Tipo B a base de gelatina sistema nanovectors ingeniería (gens) fue desarrollado para la entrega de genes sistémicos y transfección en el tratamiento del cáncer de páncreas. Por la modificación con el receptor de factor de crecimiento epidérmico (EGFR) péptido específico en la superficie de nanparticles, podrían dirigir a los receptores EGFR y la liberación del plásmido en la reducción de medio ambiente, tales como altas concentraciones de glutatión intracel...

Video: 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.

La evaluación de la administración de genes nanopartículas poliméricas por nanopartículas de análisis de seguimiento y de alto rendimiento Citometría de Flujo

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

Investigación

Bioingeniería

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.

Trasplante De InducidaS Pluripotentes Derivadas De Células Madre Mesoangioblastos Como Progenitores Miógenos En Modelos De Ratón De La Regeneración Muscular

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.

Células Madre Programación para Terapéutico Angiogénesis Uso Biodegradable polimérico nanopartículas

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.

Factor de Crecimiento de electrospinning Liberar microesferas en Fibrosa andamios

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.

El estudio de la estequiometría de factor de crecimiento epidérmico en células intactas utilizando microscopía correlativa

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.

Entrega de Therapeutic siRNA al SNC Usando catiónicos y aniónicos Los liposomas

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.

Complejo de polielectrolito para la unión a heparina de entrega osteogénico Factor de Crecimiento de dominio

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.

Fabricación y entrega de medicamentos Aplicaciones de seda nanopartículas

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.

Preparación y caracterización de nuevas nanopartículas que imitan las HDL para la encapsulación del factor de crecimiento nervioso

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.

Organoides neuronales humanos para el estudio del cáncer cerebral y las enfermedades neurodegenerativas

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