Name: porous silicon microparticles for delivery of sirna therapeutics
Uploaded: 2015-01-15T14:00:00
Description: Watch this Scientific Journal Video about Porous Silicon Microparticles for Delivery of siRNA Therapeutics at JoVE.com

The authors acknowledge financial support from Houston Methodist Research Institute, the National Natural Science Foundation of China (Nos., 21231007 and 21121061), the Ministry of Education of China (Nos., 20100171110013 and 313058), the National Basic Research Program of China (973 Program No. 2014CB845604), and the Fundamental Research Funds for the Central Universities.

1. PCPS Particle Preparation
<ol>
	<li>Oxidize non-functionalized porous silicon particles in a 30% solution of hydrogen peroxide at 95 &#176;C for 2 hr. Aminate the oxidized particles in 2% (3-&#8203;aminopropyl)&#8203;triethoxysilane solution in isopropyl alcohol for 2 days at 65 &#176;C with gentle stirring.</li>
	<li>Centrifuge the solution for 30 min at 18,800 x g and wash the particles twice in isopropyl alcohol and three times in ethanol, using brief sonication to suspend the pellet. Leave the particles in ethan...

<ol>
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O., Evangelopoulos, M., Chiappini, C., Liu, X., Ferrari, M., Tasciotti, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Degradation+and+biocompatibility+of+multistage+nanovectors+in+physiological+systems.">Degradation and biocompatibility of multistage nanovectors in physiological systems.</a> J Biomed Mater Res A. 102 (10), 3540-3549 (2014).</li><li>Shen, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhancing+chemotherapy+response+with+sustained+EphA2+silencing+using+multistage+vector+delivery.">Enhancing chemotherapy response with sustained EphA2 silencing using multistage vector delivery.</a> Clin Cancer Res. 19 (7), 1806-1815 (2013).</li><li>Xu, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multistage+vectored+siRNA+targeting+ataxia-telangiectasia+mutated+for+breast+cancer+therapy.">Multistage vectored siRNA targeting ataxia-telangiectasia mutated for breast cancer therapy.</a> Small. 9 (9-10), 1799-1808 .</li><li>Shen, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+capacity+nanoporous+silicon+carrier+for+systemic+delivery+of+gene+silencing+therapeutics.">High capacity nanoporous silicon carrier for systemic delivery of gene silencing therapeutics.</a> ACS Nano. 7 (11), 9867-9880 (2013).</li><li>Zhang, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polycation-functionalized+nanoporous+silicon+particles+for+gene+silencing+on+breast+cancer+cells.">Polycation-functionalized nanoporous silicon particles for gene silencing on breast cancer cells.</a> Biomaterials. 35 (1), 423-431 (2014).</li><li>Ozpolat, B., Sood, A. 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This protocol describes a method for the successful delivery and transfection of siRNA into cells. In particular, the delivery of siRNA is achieved by using a multifunctional platform consisting of polycation-functionalized pSi particles. The use of siRNA therapy has great potential, e.g., cancer treatment, as various oncogenes can be targeted with high specificity. Therefore, there exists a demand to develop siRNA delivery vehicles, which can mitigate the challenges of siRNA therapy. In conclusion, we have outl...

Small interfering RNAs (siRNAs) are double-stranded RNA molecules that can suppress the expression of genes. In recent years, siRNAs have been developed as a new generation of biodrugs that show therapeutic potential for future use in clinical applications1-5. However, the successful implementation of siRNA therapy remains a considerable challenge, due to degradation by nucleases, poor intracellular uptake, low transfection efficiency and inefficient release from the endosome/lysosome5. Many of these hurdles can be overcome by the development of delivery platforms, which can safely and efficiently deliver siRNA to diseased tissue. Compared to viral carriers, non-viral platforms provide several advantages, such as safety, low cost and ease of tailoring. In particular, cationic nanoparticles, such as polymers and lipids, have proved useful for siRNA delivery3.
Previously, we have developed a discoidal drug delivery system, termed the multistage vector (MSV). This platform is based on sequential stages, in which one vehicle is released from another. The first stage vehicle is a microparticle made from biodegradable porous silicon (pSi), while the second stage vehicles are nanoparticles loaded with drugs or contrast agents6,7. The nanoparticles, which are embedded in the pSi material, are gradually released as the Si degrades8. A benefit of using Si particles is that the morphology and surface characteristics can easily be tailored to achieve optimal biodistribution and drug release. Recently, the successful use of the MSV platform for the delivery of siRNA liposomes to tumor tissue was shown in an ovarian and breast cancer mouse model9, 10.
In this work, we have fabricated a universal delivery system for siRNA based on the principals of the MSV platform. The efficacy of this delivery system has previously been demonstrated using different siRNA molecules11. The system is a polycation-functionalized porous silicon (PCPS) carrier, consisting of pSi grafted with polyethylenimine (PEI) and arginine (Arg). PEI can aid in forming electrostatic interactions with siRNA, while Arg and pSi can serve to reduce the toxicity of PEI, as previously demonstarted11. In addition, the presence of PEI can assist in intracellular uptake and endosomal escape, while the pSi microparticles enable siRNA protection and sustained release. The pSi particles gradually degrade under physiological conditions, thereby resulting in the formation of Arg-PEI/siRNA nanoparticles (Figure 1), which have a distinct morphology and a narrow size distribution11. For details regarding the stability of the PCPS/siRNA system, please refer to the study by Shen et al.11. This PCPS platform differs from the conventional MSV, since the second stage nanoparticles are not initially present in the carrier, but are formed over time as the first-stage carrier degrades11, 12. The siRNA loading efficiency, cytotoxicity and gene silencing efficiency of the PCPS system has been evaluated in vitro. Transfection efficiency was measured using siRNA against the ataxia telangiectasia mutated (ATM) oncogene, which is involved in DNA repair10. Previously, the suppression of ATM has been shown to decrease tumor growth in a breast cancer model10.

<table border="0" cellpadding="0" cellspacing="0" width="1812">
	<tbody>
		<tr height="55">
			<td height="55" style="height:55px;width:605px;">Name of the Material/Equipment</td>
			<td style="width:421px;">Company/Institution</td>
			<td style="width:133px;">Catalog Number</td>
			<td style="width:653px;">Comments/Description</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Polyethylenimine (PEI), branched</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">408727</td>
			<td style="width:653px;">Average molecular weight ~25,000 Da</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">L-Arginine</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">A5006</td>
			<td style="width:653px;">Reagent grade, &#8805;98%</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Boc-Asp-OH</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">408-468</td>
			<td style="width:653px;">99%</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">(3-&#8203;Aminopropyl)&#8203;triethoxysilane</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">440140</td>
			<td style="width:653px;">99%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Hydrogen peroxide solution</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">216763</td>
			<td style="width:653px;">30&#160;wt. % in H2O</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Sulfuric acid</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">339741</td>
			<td style="width:653px;">100.00%</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Isopropyl alcohol</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">W292907</td>
			<td style="width:653px;">&#8805;99.7%</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Ethanol</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">459844</td>
			<td>&#8805;99.5%&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">N-(3-Dimethylaminopropyl)-N&#8242;-ethylcarbodiimide hydrochloride (EDC)</td>
			<td>Sigma-Aldrich</td>
			<td>03449</td>
			<td>&#8805;99%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Albumin from bovine serum</td>
			<td>Sigma-Aldrich</td>
			<td>A7030-10G</td>
			<td>Blocking agent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Ataxia-telangiectasia mutated siRNA&#160;</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;"></td>
			<td style="width:653px;">Designed in-house</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Tris Acetate-EDTA buffer</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">T9650</td>
			<td style="width:653px;">For DNA agarose gel electrophoresis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Penicillin-Streptomycin</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td>P4333</td>
			<td style="width:653px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Fetal Bovine Serum</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td>F2442</td>
			<td style="width:653px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">TWEEN 20</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td>P1379</td>
			<td style="width:653px;">Polyethylene glycol sorbitan monolaurate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">2-Mercaptoethanol</td>
			<td style="width:421px;">Sigma Aldrich</td>
			<td>M6250</td>
			<td style="width:653px;">For Western blot</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Sodium dodecyl sulfate</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td>L3771</td>
			<td style="width:653px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Sodium phosphate monobasic</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td>71496</td>
			<td style="width:653px;">For making phosphate buffer&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Sodium phosphate dibasic</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td>71640</td>
			<td style="width:653px;">For making phosphate buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Anti-Mouse IgG</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">A4416</td>
			<td style="width:653px;">Secondary antibody (anti-mouse) for Western blot</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">N-Hydroxysuccinimide (NHS)</td>
			<td style="width:421px;">Sigma-Aldrich</td>
			<td style="width:133px;">130672</td>
			<td style="width:653px;">98%</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">CELLSTAR 96W Microplate Tissue Culture Treated Clear w/ Lid</td>
			<td style="width:421px;">Greiner Bio-One</td>
			<td style="width:133px;">655182</td>
			<td style="width:653px;">96-well plate</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">10X Tris-Glycine Liquid</td>
			<td style="width:421px;">Li-Cor&#160;</td>
			<td style="width:133px;">928-40010</td>
			<td style="width:653px;">Transfer buffer for Western blot</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Paraformaldehyde solution 4% in PBS&#160;</td>
			<td style="width:421px;">Santa Cruz</td>
			<td>Sc-281692</td>
			<td style="width:653px;">Fixation of cells</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;">CellTiter 96 AQueous Non-Radioactive Cell Proliferation Assay (MTS)</td>
			<td style="width:421px;">Promega</td>
			<td style="width:133px;">G5421</td>
			<td style="width:653px;">Proliferation assay</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Phosphate buffered saline</td>
			<td style="width:421px;">Fisher Scientific</td>
			<td style="width:133px;">BP399-500</td>
			<td style="width:653px;">10 X Solution</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Corning cellgro Dulbecco&#39;s Modification of Eagle&#39;s (Mod.)</td>
			<td style="width:421px;">Fisher Scientific&#160;</td>
			<td style="width:133px;">MT-15-017-CM</td>
			<td style="width:653px;">Cell culture media, 1X solution</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Triton X-100</td>
			<td style="width:421px;">Fisher Scientific</td>
			<td>AC21568-2500</td>
			<td style="width:653px;">Octyl phenol ethoxylate, permeabilization agent</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Cover glass</td>
			<td style="width:421px;">Fisher Scientific</td>
			<td>12-530C&#160;</td>
			<td style="width:653px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Methanol</td>
			<td style="width:421px;">Fisher Scientific&#160;</td>
			<td>A412-1</td>
			<td style="width:653px;">For Western blot transfer buffer</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Plastic Cuvettes</td>
			<td style="width:421px;">Fisher Scientific&#160;</td>
			<td style="width:133px;">14-377-010&#160;</td>
			<td style="width:653px;">For size measurements using Zetasizer Nano ZS</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Molecular BioProducts RNase AWAY Surface Decontaminant</td>
			<td style="width:421px;">Fisher Scientific</td>
			<td style="width:133px;">14-754-34</td>
			<td style="width:653px;">Spray for removing RNAse contamination</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Agarose</td>
			<td style="width:421px;">Fisher Scientific</td>
			<td style="width:133px;">BP165-25</td>
			<td style="width:653px;">Low melting point, for running RNA samples</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ProLong Gold Antifade Reagent with DAPI&#160;</td>
			<td style="width:421px;">Invitrogen</td>
			<td>P36935</td>
			<td style="width:653px;">Antifade reagent with DAPI, nucelus detection</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Alexa Fluor 488 Phalloidin</td>
			<td style="width:421px;">Invitrogen</td>
			<td style="width:133px;">A12379</td>
			<td style="width:653px;">Dissolve 300 units in 1.5 ml methanol, detection of filamentous actin</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">SYBR Safe DNA Gel Stain</td>
			<td style="width:421px;">Invitrogen</td>
			<td style="width:133px;">S33102</td>
			<td style="width:653px;">Visualization of RNA</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Negative Control siRNA</td>
			<td style="width:421px;">Qiagen</td>
			<td style="width:133px;">1022076</td>
			<td style="width:653px;">Control siRNA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">AllStars Neg. siRNA AF 555</td>
			<td style="width:421px;">Qiagen</td>
			<td style="width:133px;">1027294</td>
			<td style="width:653px;">Fluorescent control siRNA</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Cell scraper</td>
			<td style="width:421px;">Celltreat</td>
			<td>229310</td>
			<td style="width:653px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BioLite Multidishes and Microwell Plates</td>
			<td style="width:421px;">Thermo Scientific</td>
			<td>130184</td>
			<td style="width:653px;">6-well plate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Pierce LDS Sample Loading Buffer (4X)&#160;</td>
			<td style="width:421px;">Thermo Scientific</td>
			<td>84788</td>
			<td style="width:653px;">Sample loading buffer for Western blot</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Pierce BCS Protein Assay Kit</td>
			<td style="width:421px;">Thermo Scientific</td>
			<td style="width:133px;">23227</td>
			<td style="width:653px;">Protein quantification assay</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Halt Protease Inhibitor Single-Use Cocktails (100X)</td>
			<td style="width:421px;">Thermo Scientific</td>
			<td style="width:133px;">78430</td>
			<td style="width:653px;">Protease inhibitor cocktail, use at 1X</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">M-PER Mammalian Protein Extraction Reagent</td>
			<td style="width:421px;">Thermo Scientific&#160;</td>
			<td style="width:133px;">78501</td>
			<td style="width:653px;">Protein extraction reagent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Sorvall Legend Micro 21R</td>
			<td>Thermo Scientific</td>
			<td>75002440</td>
			<td>Centrifuge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Beta Actin Antibody&#160;</td>
			<td>Thermo Scientific&#160;</td>
			<td>MA1-91399</td>
			<td>&#946;-actin primary antibody (from mouse) for western blor</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">6X TriTrack DNA Loading Dye</td>
			<td style="width:421px;">Thermo Scientific</td>
			<td>R1161</td>
			<td style="width:653px;">DNA loading dye</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nuclease-Free Water&#160;</td>
			<td style="width:421px;">Life Technologies</td>
			<td>AM9938</td>
			<td style="width:653px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Non-Fat Dry Milk</td>
			<td style="width:421px;">Lab Scientific</td>
			<td>M0841</td>
			<td style="width:653px;">For Western blot</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2-well BD Falcon culture slides&#160;</td>
			<td style="width:421px;">BD Biosciences</td>
			<td>354102</td>
			<td style="width:653px;">2-well culture slides</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Amersham ECL Western blot detection reagent.&#160;</td>
			<td style="width:421px;">GE Healthcare Life Sciences</td>
			<td style="width:133px;">RPN2106</td>
			<td style="width:653px;">Western blot detection reagent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">BA Membranes</td>
			<td style="width:421px;">GE Healthcare Life Sciences</td>
			<td>10402096</td>
			<td style="width:653px;">Nitrocellulose membrane for Wester blot</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ATM (D2E2) Rabbit mAb</td>
			<td style="width:421px;">Cell Signaling</td>
			<td>2873S</td>
			<td style="width:653px;">ATM primary antibody (from rabbit) for Western blot</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Anti-rabbit IgG, HRP-linked Antibody</td>
			<td style="width:421px;">Cell Signaling&#160;</td>
			<td>7074</td>
			<td style="width:653px;">Secondary antibody (anti-rabbit) for Western blot&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Folded capillary cells</td>
			<td style="width:421px;">Malvern&#160;</td>
			<td style="width:133px;">DTS 1061</td>
			<td style="width:653px;">For zeta potentail measurements using Zetasizer Nano ZS</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">MDA-MB-231 cell line</td>
			<td style="width:421px;">ATCC</td>
			<td style="width:133px;">HTB-26</td>
			<td style="width:653px;">Mammary Gland/Breast</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">12% Mini-PROTEAN TGX Gel</td>
			<td>Bio-rad</td>
			<td>456-1043&#160;</td>
			<td style="width:653px;">For Western blot</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Biorad PowerPac HC</td>
			<td>Bio-rad</td>
			<td>164-5052</td>
			<td>Power supply for electrophoresis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10x Tris/Glycine/SDS Buffer</td>
			<td>Bio-rad</td>
			<td>161-0732</td>
			<td>Running buffer for Western blot</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Wide Mini-Sub Cell GT Cell</td>
			<td>Bio-rad</td>
			<td>170-4405</td>
			<td>Electrophoresis equipment for DNA agarose gel&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mini-PROTEAN Tetra cell</td>
			<td>Bio-rad</td>
			<td>165-8000</td>
			<td>Electrophoresis equipment for Western blot</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ChemiDoc XRS+ System with Image Lab Software</td>
			<td>Bio-rad</td>
			<td>170-8265</td>
			<td>Image acquisition and analysis software for gels and blots</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">4&#34; (10cm) dia., 5x7mm diced Silicon Wafer</td>
			<td>Ted Pella&#160;</td>
			<td>16007</td>
			<td>Silicon waferfor scanning electron microscopy and atomic force microscopy</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Thermomixer R</td>
			<td>Eppendorf</td>
			<td>22670107</td>
			<td>Shaker&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isoton II diluent</td>
			<td>Beckman Coulter</td>
			<td>8546719</td>
			<td>Isoton diluent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Multisizer 4 Coulter Counter</td>
			<td>Beckman Coulter</td>
			<td>A63076</td>
			<td>Particle counting analyzer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Non-functionalized porous silicon particles&#160;</td>
			<td style="width:421px;">Microelectronics Research Center, University of Texas at Austin</td>
			<td style="width:133px;"></td>
			<td style="width:653px;">Dicoidal shape. 2.6 &#956;m (diameter) x 0.7 &#956;m (hight), provided in isopropyl alcohol</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Zetasizer Nano ZS</td>
			<td style="width:421px;">Malvern</td>
			<td style="width:133px;"></td>
			<td style="width:653px;">Particle analyzer system for size and zeta potential&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Scanning Electron Microscope</td>
			<td style="width:421px;">FEI</td>
			<td style="width:133px;"></td>
			<td style="width:653px;">Particle size and shape&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:605px;">Atomic Force Microscope</td>
			<td style="width:421px;">Bruker</td>
			<td style="width:133px;"></td>
			<td style="width:653px;">Particle size and shape</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:605px;">Fluo ViewTM 1000 Confocal Microscope</td>
			<td style="width:421px;">Olympus</td>
			<td style="width:133px;"></td>
			<td style="width:653px;">Visualization of fixed and live cells</td>
		</tr>
	</tbody>
</table>

porous silicon microparticles for delivery of sirna therapeutics

Small interfering RNA (siRNA) can be used to suppress gene expression, thereby providing a new avenue for the treatment of various diseases. However, the successful implementation of siRNA therapy requires the use of delivery platforms that can overcome the major challenges of siRNA delivery, such as enzymatic degradation, low intracellular uptake and lysosomal entrapment. Here, a protocol for the preparation and use of a biocompatible and effective siRNA delivery system is presented. This platform consists of polyethylenimine (PEI) and arginine (Arg)-grafted porous silicon microparticles, which can be loaded with siRNA by performing a simple mixing step. The silicon particles are gradually degraded over time, thereby triggering the formation of Arg-PEI/siRNA nanoparticles. This delivery vehicle provides a means for protecting and internalizing siRNA, without causing cytotoxicity. The major steps of polycation functionalization, particle characterization, and siRNA loading are outlined in detail. In addition, the procedures for determining particle uptake, cytotoxicity, and transfection efficacy are also described.

This protocol describes the use of a non-viral delivery system for safe and efficient siRNA transfection. The SEM results reveal that the PCPS particles are cylindrical in shape and have a diameter of 2.6 &#956;m (Figure 2A). The particles are positively charged with a zeta potential of approximately +8.21 (Figure 2B), thereby enabling electrostatic binding with negatively charged nucleotides. Confocal images of different layers of the PCPS particles demonstrate that fluorescent control ...

Watch this Scientific Journal Video about Porous Silicon Microparticles for Delivery of siRNA Therapeutics at JoVE.com

Porous Silicon Microparticles for Delivery of siRNA Therapeutics

Delivery remains the main challenge for the therapeutic implementation of small interfering RNA (siRNA). This protocol involves the use of a multifunctional and biocompatible siRNA delivery platform, consisting of arginine and polyethylenimine grafted porous silicon microparticles.

Small interfering RNA (siRNA) can be used to suppress gene expression, thereby providing a new avenue for the treatment of various diseases. However, the ...

Research

JoVE Journal

Bioengineering

Soft Lithographic Functionalization and Patterning Oxide-free Silicon and Germanium

The development of hybrid electronic devices relies in large part on the integration of (bio)organic materials and inorganic semiconductors through a ...

Self-reporting Scaffolds for 3-Dimensional Cell Culture

Culturing cells in 3D on appropriate scaffolds is thought to better mimic the in vivo microenvironment and increase cell-cell interactions. The resulting ...

Optical Detection of E. coli Bacteria by Mesoporous Silicon Biosensors

Optical Detection of E. coli Bacteria by Mesoporous Silicon Biosensors

A label-free optical biosensor based on a nanostructured porous Si is designed for rapid capture and detection of Escherichia coli K12 bacteria, as a ...

Microscale Vortex-assisted Electroporator for Sequential Molecular Delivery

Electroporation has received increasing attention in the past years, because it is a very powerful technique for physically introducing non-permeant ...

Preparation of Silicon Nanowire Field-effect Transistor for Chemical and Biosensing Applications

Surveillance using biomarkers is critical for the early detection, rapid intervention, and reduction in the incidence of diseases. In this study, we ...

Synthesis of Thermogelling Poly(N-isopropylacrylamide)-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering

Synthesis of Thermogelling PolyN-isopropylacrylamide-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering

Injectable biomaterials are defined as implantable materials that can be introduced into the body as a liquid and solidify in situ. Such materials offer ...

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 ...

Designing Porous Silicon Films as Carriers of Nerve Growth Factor

Despite the great potential of NGF for treating neurodegenerative diseases, its therapeutic administration represents a significant challenge as the ...

3D Printed Porous Cellulose Nanocomposite Hydrogel Scaffolds

This work demonstrates the use of three-dimensional (3D) printing to produce porous cubic scaffolds using cellulose nanocomposite hydrogel ink, with ...

Preparation of Neutrally-charged, pH-responsive Polymeric Nanoparticles for Cytosolic siRNA Delivery

The success of siRNA as a targeted molecular medicine is dependent upon its efficient cytosolic delivery to cells within the tissue of pathology. Clinical ...