EBA (DGE-1746891) and KRR (DGE-1232825) thank the NSF Graduate Research Fellowship program for support. RAM thanks the National Research Service Award NIH NCI F31 (F31CA214147) and the Achievement Rewards for College Scientists Fellowship for support. The authors thank the NIH (R01EB016721 and R01CA195503), the Research to Prevent Blindness James and Carole Free Catalyst Award, and the JHU Bloomberg-Kimmel Institute for Cancer Immunotherapy for support.

All methods described here have been approved by the Institutional Animal Care and Use Committee (IACUC) of Johns Hopkins University.
1. Fabrication of Spherical PLGA Particles of Tunable Size
<ol>
	<li>Preparation of materials for particle synthesis
	<ol>
		<li>Prepare 5% w/w polyvinyl alcohol (PVA) solution.
		<ol>
			<li>Add 500 mL of deionized (DI) water to an Erlenmeyer flask with a magnetic stir bar and place on hot plate stirrer at 500 rpm and monitor temperature with thermometer. Cov...

<ol>
	<li>Eggermont, L. J., Paulis, L. E., Tel, J., Figdor, C. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Towards+efficient+cancer+immunotherapy:+Advances+in+developing+artificial+antigen-presenting+cells.">Towards efficient cancer immunotherapy: Advances in developing artificial antigen-presenting cells.</a> Trends in Biotechnology. 32 (9), 456-465 (2014).</li><li>Maus, M. V., Riley, J. L., Kwok, W. W., Nepom, G. T., June, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=HLA+tetramer-based+artificial+antigen-presenting+cells+for+stimulation+of+CD4++T+cells.">HLA tetramer-based artificial antigen-presenting cells for stimulation of CD4+ T cells.</a> Clinical Immunology. 106 (1), 16-22 (2003).</li><li>Oelke, 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=Ex+vivo+induction+and+expansion+of+antigen-specific+cytotoxic+T+cells+by+HLA-Ig-coated+artificial+antigen-presenting+cells.">Ex vivo induction and expansion of antigen-specific cytotoxic T cells by HLA-Ig-coated artificial antigen-presenting cells.</a> Nature Medicine. 9 (5), 619-624 (2003).</li><li>Rudolf, D., 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=Potent+costimulation+of+human+CD8+T+cells+by+anti-4-1BB+and+anti-CD28+on+synthetic+artificial+antigen+presenting+cells.">Potent costimulation of human CD8 T cells by anti-4-1BB and anti-CD28 on synthetic artificial antigen presenting cells.</a> Cancer Immunology, Immunotherapy. 57 (2), 175-183 (2008).</li><li>Tham, E. L., Jensen, P. L., Mescher, M. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Activation+of+antigen-specific+T+cells+by+artificial+cell+constructs+having+immobilized+multimeric+peptide-class+I+complexes+and+recombinant+B7-Fc+proteins.">Activation of antigen-specific T cells by artificial cell constructs having immobilized multimeric peptide-class I complexes and recombinant B7-Fc proteins.</a> Journal of Immunological Methods. 249 (1-2), 111-119 (2001).</li><li>Perica, K., 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=Magnetic+field-induced+T+cell+receptor+clustering+by+nanoparticles+enhances+T+cell+activation+and+stimulates+antitumor+activity.">Magnetic field-induced T cell receptor clustering by nanoparticles enhances T cell activation and stimulates antitumor activity.</a> ACS Nano. 8 (3), 2252-2260 (2014).</li><li>Steenblock, E. R., Fadel, T., Labowsky, M., Pober, J. S., Fahmy, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+artificial+antigen-presenting+cell+with+paracrine+delivery+of+IL-2+impacts+the+magnitude+and+direction+of+the+T+cell+response.">An artificial antigen-presenting cell with paracrine delivery of IL-2 impacts the magnitude and direction of the T cell response.</a> The Journal of Biological Chemistry. 286 (40), 34883-34892 (2011).</li><li>Zhang, L., 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=Paracrine+release+of+IL-2+and+anti-CTLA-4+enhances+the+ability+of+artificial+polymer+antigen-presenting+cells+to+expand+antigen-specific+T+cells+and+inhibit+tumor+growth+in+a+mouse+model.">Paracrine release of IL-2 and anti-CTLA-4 enhances the ability of artificial polymer antigen-presenting cells to expand antigen-specific T cells and inhibit tumor growth in a mouse model.</a> Cancer Immunology, Immunotherapy. 66 (9), 1229-1241 (2017).</li><li>Mescher, M. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+contact+requirements+for+activation+of+cytotoxic+T+lymphocytes.">Surface contact requirements for activation of cytotoxic T lymphocytes.</a> The Journal of Immunology. 149 (7), 2402-2405 (1992).</li><li>Steenblock, E. R., Fahmy, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comprehensive+platform+for+ex+vivo+T-cell+expansion+based+on+biodegradable+polymeric+artificial+antigen-presenting+cells.">A comprehensive platform for ex vivo T-cell expansion based on biodegradable polymeric artificial antigen-presenting cells.</a> Molecular Therapy. 16 (4), 765-772 (2008).</li><li>Fifis, T., 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=Size-dependent+immunogenicity:+therapeutic+and+protective+properties+of+nano-vaccines+against+tumors.">Size-dependent immunogenicity: therapeutic and protective properties of nano-vaccines against tumors.</a> The Journal of Immunology. 173 (5), 3148-3154 (2004).</li><li>Sunshine, J. C., Perica, K., Schneck, J. P., Green, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Particle+shape+dependence+of+CD8++T+cell+activation+by+artificial+antigen+presenting+cells.">Particle shape dependence of CD8+ T cell activation by artificial antigen presenting cells.</a> Biomaterials. 35 (1), 269-277 (2014).</li><li>Meyer, R. A., 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=Biodegradable+nanoellipsoidal+artificial+antigen+presenting+cells+for+antigen+specific+T-cell+activation.">Biodegradable nanoellipsoidal artificial antigen presenting cells for antigen specific T-cell activation.</a> Small. 11 (13), 1519-1525 (2015).</li><li>Champion, J. A., Katare, Y. K., Mitragotri, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Particle+shape:+a+new+design+parameter+for+micro-+and+nanoscale+drug+delivery+carriers.">Particle shape: a new design parameter for micro- and nanoscale drug delivery carriers.</a> Journal of Controlled Release. 121 (1-2), 3-9 (2007).</li><li>Meyer, R. A., Meyer, R. S., Green, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+automated+multidimensional+thin+film+stretching+device+for+the+generation+of+anisotropic+polymeric+micro-+and+nanoparticles.">An automated multidimensional thin film stretching device for the generation of anisotropic polymeric micro- and nanoparticles.</a> Journal of Biomedical Materials Research Part A. 103 (8), 2747-2757 (2015).</li><li>Ho, C. C., Keller, A., Odell, J. A., Ottewill, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+monodisperse+ellipsoidal+polystyrene+particles.">Preparation of monodisperse ellipsoidal polystyrene particles.</a> Colloid and Polymer Science. 271 (5), 469-479 (1993).</li><li>Shum, H. C., 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=Droplet+microfluidics+for+fabrication+of+non-spherical+particles.">Droplet microfluidics for fabrication of non-spherical particles.</a> Macromolecular Rapid Communications. 31 (2), 108-118 (2010).</li><li>Lan, W., Li, S., Xu, J., Luo, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controllable+preparation+of+nanoparticle-coated+chitosan+microspheres+in+a+co-axial+microfluidic+device.">Controllable preparation of nanoparticle-coated chitosan microspheres in a co-axial microfluidic device.</a> Lab on a Chip. 11 (4), 652-657 (2011).</li><li>Yang, S., 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=Microfluidic+synthesis+of+multifunctional+Janus+particles+for+biomedical+applications.">Microfluidic synthesis of multifunctional Janus particles for biomedical applications.</a> Lab on a Chip. 12 (12), 2097-2102 (2012).</li><li>Zhou, Z., Anselmo, A. C., Mitragotri, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+protein-based,+rod-shaped+particles+from+spherical+templates+using+layer-by-layer+assembly.">Synthesis of protein-based, rod-shaped particles from spherical templates using layer-by-layer assembly.</a> Advanced Materials. 25 (19), 2723-2727 (2013).</li><li>Jang, S. G., 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=Striped,+ellipsoidal+particles+by+controlled+assembly+of+diblock+copolymers.">Striped, ellipsoidal particles by controlled assembly of diblock copolymers.</a> Journal of the American Chemical Society. 135 (17), 6649-6657 (2013).</li><li>Petzetakis, N., Dove, A. P., O'Reilly, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cylindrical+micelles+from+the+living+crystallization-driven+self-assembly+of+poly(lactide)-containing+block+copolymers.">Cylindrical micelles from the living crystallization-driven self-assembly of poly(lactide)-containing block copolymers.</a> Chemical Science. 2 (5), 955-960 (2011).</li><li>Rolland, J. P., 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=Direct+fabrication+and+harvesting+of+monodisperse,+shape-specific+nanobiomaterials.">Direct fabrication and harvesting of monodisperse, shape-specific nanobiomaterials.</a> Journal of the American Chemical Society. 127 (28), 10096-10100 (2005).</li><li>Meyer, R. 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This protocol details a versatile method for the precise generation of anisotropic polymeric particles. The thin film stretching technique described here is scalable, highly reproducible and inexpensive. Alternative techniques for generating anisotropic particles suffer from many limitations, including high cost, low throughput, and limited particle size. The thin film stretching approach is also advantageous because the particles are modified to be anisotropic after synthesis, and, as a result, is compatible with a wide...

Artificial antigen presenting cells (aAPC) have shown promise as immunomodulatory agents because they can generate a robust antigen-specific T cell response. Essential to these platforms are their ability to efficiently present crucial signals for T cell activation. Acellular aAPC are an attractive alternative to cell-based aAPC because they are easier and less costly to fabricate, face fewer challenges during scale-up and translation, and alleviate risks associated with cell-based therapies. Acellular aAPC also allow for a high degree of control over signal presentation parameters and physical properties of the surface that will interface with T cells1.
aAPC must recapitulate a minimum of two signals essential for T cell activation. Signal 1 provides antigen recognition and occurs when the T cell receptor (TCR) recognizes and engages with an MHC class I or II bearing its cognate antigen, culminating in signaling through the TCR complex. To bypass the antigen specificity requirement, aAPC systems often bear an agonistic monoclonal antibody against the CD3 receptor, which nonspecifically stimulates the TCR complex. Recombinant forms of MHC, particularly MHC multimers, have also been used on the surface of aAPC to provide antigen specificity2,3. Signal 2 is a costimulatory signal that directs T cell activity. To provide the costimulation necessary for T cell activation, the CD28 receptor is generally stimulated with an agonistic antibody presented on the aAPC surface, although other costimulatory receptors such as 4-1BB have been successfully targeted4. Signal 1 and 2 proteins are typically immobilized on the surface of rigid particles to synthesize aAPC. Historically, aAPC have been fabricated from a variety of materials, including polystyrene4,5 and iron dextran6. Newer systems utilize biodegradable polymers like poly(lactic-co-glycolic acid) (PLGA) to generate aAPC that can be easily coupled to signal proteins, are suitable for direct administration in vivo, and can facilitate the sustained release of encapsulated cytokines or soluble factors to augment T cell activation7,8.
In addition to the presence of necessary signal proteins, receptor engagement over a sufficiently large surface area during the aAPC/T cell interaction is essential for T cell activation. Thus, physical parameters of the aAPC such as size and shape drastically alter their available contact area and affect their ability to stimulate T cells. Micron-sized aAPC have been shown to be more effective at stimulating T cells than their nanoscale counterparts9,10. However, nano-aAPC can have superior biodistribution and better drainage to the lymph nodes that may enhance their performance in vivo over micro-aAPC11. Shape is another variable of interest in particle-based aAPC systems. Anisotropic aAPC have recently been shown to be more effective than isotropic particles at stimulating T cells, mainly due to enhanced interaction with target cells coupled with reduced non-specific cell uptake. Cells preferentially bind to the long axis of ellipsoidal particles, and the larger radius of curvature and flatter surface allow for more contact between the aAPC and T cell12. The long axis of ellipsoidal particles also discourages phagocytosis, resulting in increased circulation time compared to spherical particles following in vivo administration12,13. Because of these advantages, ellipsoidal particles mediate greater expansion of antigen-specific T cells in vitro and in vivo compared to spherical particles, an effect observed at both the micro and nanoscales12,13. There are various strategies to fabricate anisotropic particles, but thin-film stretching is a simple, widely accepted method used to generate a range of diverse particle shapes14. Following synthesis, particles are cast into films and stretched in one or two dimensions at a temperature above the glass transition temperature of the particle material. The film is then dissolved to retrieve the particles. Despite growing interest in anisotropic particles, current approaches for fabricating particle-based aAPC are mostly limited to isotropic systems, and methods of altering particle shape can be difficult to implement, incompatible with certain aAPC synthesis strategies, and lack precision and reproducibility15. Our thin-film stretching technique can be performed manually or in an automated fashion to rapidly generate anisotropic particles synthesized from a variety of biodegradable polymers, stretched to a desired aspect ratio in one or two dimensions15.
Based on our previous work, we developed a biodegradable particle-based approach combined with scalable thin-film stretching technology to rapidly generate aAPC with tunable size and shape in a standardized fashion for T cell expansion ex vivo or in vivo. Our protein conjugation strategy can be used to couple any protein(s) of interest to carboxyl groups on the particle surface at a desired density, giving this aAPC system a high degree of flexibility. We also describe methods to characterize the size, morphology, and surface protein content of aAPC, and to evaluate their functionality in vitro. This protocol can be easily adapted to expand immune cells ex vivo or in vivo for a variety of immunotherapeutic applications.

<table>
	<tbody>
		<tr>
			<td>Poly(vinyl alcohol), MW 25000, 88% hydrolyzed</td>
			<td>Polysciences, Inc.</td>
			<td>02975-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Glycerol</td>
			<td>Sigma-Aldrich</td>
			<td>G9012</td>
			<td></td>
		</tr>
		<tr>
			<td>Digital Thermometer</td>
			<td>Fluke</td>
			<td>N/A</td>
			<td>Model name: Fluke 52 II</td>
		</tr>
		<tr>
			<td>Immersion Temperature Probe</td>
			<td>Fluke</td>
			<td>N/A</td>
			<td>Model name: Fluke 80PK 22</td>
		</tr>
		<tr>
			<td>Digital Hotplate &#38; Stirrer</td>
			<td>Benchmark Scientific</td>
			<td>H3760-HS</td>
			<td></td>
		</tr>
		<tr>
			<td>Multipoint stirrer</td>
			<td>Thermo Fisher Scientific</td>
			<td>50093538</td>
			<td></td>
		</tr>
		<tr>
			<td>Resomer RG 504 H, Poly(D,L-lactide-co-glycolide)</td>
			<td>Sigma-Aldrich</td>
			<td>719900</td>
			<td></td>
		</tr>
		<tr>
			<td>Dichloromethane</td>
			<td>Sigma-Aldrich</td>
			<td>D65100</td>
			<td></td>
		</tr>
		<tr>
			<td>Homogenizer</td>
			<td>IKA</td>
			<td>&#160;0003725001</td>
			<td></td>
		</tr>
		<tr>
			<td>Sonicator</td>
			<td>Sonics &#38; Materials, Inc.</td>
			<td>N/A</td>
			<td>Model number: VC 505</td>
		</tr>
		<tr>
			<td>Sonicator sound abating enclosure</td>
			<td>Sonics &#38; Materials, Inc.</td>
			<td>N/A</td>
			<td>Part number: 630-0427</td>
		</tr>
		<tr>
			<td>Sonicator probe</td>
			<td>Sonics &#38; Materials, Inc.</td>
			<td>N/A</td>
			<td>Part number: 630-0220</td>
		</tr>
		<tr>
			<td>Sonicator microtip</td>
			<td>Sonics &#38; Materials, Inc.</td>
			<td>N/A</td>
			<td>Part number: 630-0423</td>
		</tr>
		<tr>
			<td>High speed centrifuge</td>
			<td>Beckman Coulter</td>
			<td>N/A</td>
			<td>Model number: J-20XP (discontinued), alternative model: J-26XP</td>
		</tr>
		<tr>
			<td>High speed centrifuge rotor</td>
			<td>Beckman Coulter</td>
			<td>369691</td>
			<td>Model number: JA-17</td>
		</tr>
		<tr>
			<td>High speed polycarbonate centrifuge tubes</td>
			<td>Thermo Fisher Scientific</td>
			<td>3118-0050</td>
			<td>50 mL, screw cap</td>
		</tr>
		<tr>
			<td>Rectangular disposable petri dish</td>
			<td>VWR International</td>
			<td>25384-322</td>
			<td>75 x 50 x 10 mm</td>
		</tr>
		<tr>
			<td>Square disposable petri dish</td>
			<td>VWR International</td>
			<td>10799-140</td>
			<td>100 mm x 100 mm</td>
		</tr>
		<tr>
			<td>LEAF&#160;Purified anti-mouse CD3&#949; Antibody</td>
			<td>Biolegend</td>
			<td>100314</td>
			<td></td>
		</tr>
		<tr>
			<td>InVivoMab anti-mouse CD28, clone 37.51</td>
			<td>Bio X Cell</td>
			<td>BE0015-1</td>
			<td></td>
		</tr>
		<tr>
			<td>N-(3-Dimethylaminopropyl)-N&#8242;-ethylcarbodiimide hydrochloride</td>
			<td>Sigma-Aldrich</td>
			<td>E6383</td>
			<td></td>
		</tr>
		<tr>
			<td>N-Hydroxysulfosuccinimide sodium salt</td>
			<td>Sigma-Aldrich</td>
			<td>56485</td>
			<td></td>
		</tr>
		<tr>
			<td>MES</td>
			<td>Sigma-Aldrich</td>
			<td>M3671</td>
			<td></td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 anti-mouse CD3 Antibody</td>
			<td>Biolegend</td>
			<td>100212</td>
			<td></td>
		</tr>
		<tr>
			<td>APC anti-mouse CD28 Antibody</td>
			<td>Biolegend</td>
			<td>102109</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning&#160;96 Well Solid Polystyrene Microplate</td>
			<td>Sigma-Aldrich</td>
			<td>CLS3915</td>
			<td>flat bottom, black polystyrene</td>
		</tr>
		<tr>
			<td>Protein LoBind Tubes, 1.5 mL</td>
			<td>Eppendorf</td>
			<td>22431081</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI 1640 Medium (+ L-Glutamine)</td>
			<td>ThermoFisher Scientific</td>
			<td>11875093</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Sigma-Aldrich</td>
			<td>F4135</td>
			<td>Heat Inactivated, sterile-filtered</td>
		</tr>
		<tr>
			<td>Ciprofloxacin</td>
			<td>Sigma-Aldrich</td>
			<td>17850</td>
			<td></td>
		</tr>
		<tr>
			<td>2-Mercaptoethanol</td>
			<td>Sigma-Aldrich</td>
			<td>M6250</td>
			<td></td>
		</tr>
		<tr>
			<td>Recombinant Human IL-2 (carrier-free)</td>
			<td>Biolegend</td>
			<td>589102</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Pyruvate (100 mM)</td>
			<td>ThermoFisher Scientific</td>
			<td>11360070</td>
			<td></td>
		</tr>
		<tr>
			<td>MEM Non-Essential Amino Acids Solution (100X)</td>
			<td>ThermoFisher Scientific</td>
			<td>11140050</td>
			<td></td>
		</tr>
		<tr>
			<td>MEM Vitamin Solution (100X)</td>
			<td>ThermoFisher Scientific</td>
			<td>11120052</td>
			<td></td>
		</tr>
		<tr>
			<td>CD8a+&#160;T Cell Isolation Kit, mouse</td>
			<td>Miltenyi Biotech</td>
			<td>130-104-075</td>
			<td></td>
		</tr>
		<tr>
			<td>CellTrace CFSE Cell Proliferation Kit</td>
			<td>ThermoFisher Scientific</td>
			<td>C34554</td>
			<td></td>
		</tr>
		<tr>
			<td>LS Columns</td>
			<td>Miltenyi Biotech</td>
			<td>130-042-401</td>
			<td></td>
		</tr>
		<tr>
			<td>MidiMACS Separator</td>
			<td>Miltenyi Biotech</td>
			<td>130-042-302</td>
			<td></td>
		</tr>
		<tr>
			<td>MACS Multistand</td>
			<td>Miltenyi Biotech</td>
			<td>130-042-303</td>
			<td></td>
		</tr>
		<tr>
			<td>Flow Cytometer</td>
			<td>Accuri C6</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Synergy 2 Multi-Detection Microplate Reader</td>
			<td>BioTek</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>autoMACS Running Buffer</td>
			<td>Miltenyi BIotech</td>
			<td>130-091-221</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Strainer</td>
			<td>ThermoFisher Scientific</td>
			<td>22363548</td>
			<td>Sterile, 70 &#181;m nylon mesh</td>
		</tr>
		<tr>
			<td>ACK Lysing Buffer</td>
			<td>ThermoFisher Scientific</td>
			<td>A1049201</td>
			<td></td>
		</tr>
		<tr>
			<td>C57BL/6J (Black 6) Mouse</td>
			<td>The Jackson Laboratory</td>
			<td>000664</td>
			<td>Male, at least 7 weeks old</td>
		</tr>
		<tr>
			<td>U-Bottom Tissue Culture Plates</td>
			<td>VWR</td>
			<td>353227</td>
			<td>Sterile, 96-well tissue culture treated polystyrene plates</td>
		</tr>
		<tr>
			<td>40 V DC Power Supply</td>
			<td>Probotix</td>
			<td>LPSK-4010</td>
			<td></td>
		</tr>
		<tr>
			<td>PTFE Coated Wire</td>
			<td>Mouser</td>
			<td>602-5858-100-01</td>
			<td>This is for a 100 ft. spool but an equivalent wire will work</td>
		</tr>
		<tr>
			<td>Stepper Motor Driver</td>
			<td>Probotix</td>
			<td>MondoStep5.6</td>
			<td></td>
		</tr>
		<tr>
			<td>IDC Connector Kit</td>
			<td>Probotix</td>
			<td>IDCM-10-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Microcontroller</td>
			<td>Probotix</td>
			<td>PBX-RF</td>
			<td></td>
		</tr>
		<tr>
			<td>4A Fuses</td>
			<td>Radio Shack</td>
			<td>2701026</td>
			<td>Equivalent fuses will work as well</td>
		</tr>
		<tr>
			<td>DB25 Male to Male Cable</td>
			<td>Probotix</td>
			<td>DB25-6</td>
			<td></td>
		</tr>
		<tr>
			<td>USB-A to USB-B Cable</td>
			<td>Staples</td>
			<td>2094915</td>
			<td>Equivalent cable will work as well</td>
		</tr>
		<tr>
			<td>8-Pin Amphenol Connectors Male and Female</td>
			<td>Mouser</td>
			<td>654-97-3100A-20-7P and 654-97-3106A20-7S</td>
			<td></td>
		</tr>
		<tr>
			<td>Stepper Motor</td>
			<td>Probotix</td>
			<td>HT23-420-8</td>
			<td></td>
		</tr>
		<tr>
			<td>Right Hand Lead Screw</td>
			<td>Roton</td>
			<td>60722</td>
			<td></td>
		</tr>
		<tr>
			<td>Left Hand Lead Screw</td>
			<td>Roton</td>
			<td>60723</td>
			<td></td>
		</tr>
		<tr>
			<td>Screws</td>
			<td>McMaster Carr</td>
			<td>92196A151</td>
			<td></td>
		</tr>
		<tr>
			<td>Neoprene Rubber</td>
			<td>McMaster Carr</td>
			<td>8698K51</td>
			<td></td>
		</tr>
		<tr>
			<td>Right Handed Flanged Lead Nut</td>
			<td>Roton</td>
			<td>91962</td>
			<td></td>
		</tr>
		<tr>
			<td>Left Handed Flanged Lead Nut</td>
			<td>Roton</td>
			<td>91963</td>
			<td></td>
		</tr>
		<tr>
			<td>Linux Control Computer</td>
			<td>Probotix</td>
			<td>LCNC-PC</td>
			<td>Any computer with matching specification and Linux operating system will work</td>
		</tr>
		<tr>
			<td>Corning bottle-top vacuum filter system</td>
			<td>Sigma-Aldrich</td>
			<td>CLS431097</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypan Blue Solution, 0.4 %</td>
			<td>ThermoFisher Scientific</td>
			<td>15250061</td>
			<td></td>
		</tr>
	</tbody>
</table>

fabrication of anisotropic polymeric artificial antigen presenting cells for cd8+ t cell activation

Artificial antigen presenting cells (aAPC) are a promising platform for immune modulation due to their potent ability to stimulate T cells. Acellular substrates offer key advantages over cell-based aAPC, including precise control of signal presentation parameters and physical properties of the aAPC surface to modulate its interactions with T cells. aAPC constructed from anisotropic particles, particularly ellipsoidal particles, have been shown to be more effective than their spherical counterparts at stimulating T cells due to increased binding and larger surface area available for T cell contact, as well as reduced nonspecific uptake and enhanced pharmacokinetic properties. Despite increased interest in anisotropic particles, even widely accepted methods of generating anisotropic particles such as thin-film stretching can be challenging to implement and use reproducibly.
To this end, we describe a protocol for the rapid, standardized fabrication of biodegradable anisotropic particle-based aAPC with tunable size, shape, and signal presentation for T cell expansion ex vivo or in vivo, along with methods to characterize their size, morphology, and surface protein content, and to assess their functionality. This approach to fabricating anisotropic aAPC is scalable and reproducible, making it ideal for generating aAPC for &#34;off-the-shelf&#34; immunotherapies.

A schematic for the automated 2D thin film stretching device is given in Figure 1. A schematic and description for a 1D thin film stretching device is given in Ho et al.17 The stretcher is constructed from aluminum parts using standard milling and machining techniques. Similar to the 1D stretcher, the 2D stretcher consists of metallic grips and guide rails. Bidirectional lead screws are used to translate linear to rotational motion. Th...

Watch this Scientific Journal Video about Fabrication of Anisotropic Polymeric Artificial Antigen Presenting Cells for CD8+ T Cell Activation at JoVE.com

Fabrication of Anisotropic Polymeric Artificial Antigen Presenting Cells for CD8+ T Cell Activation

Here, we present a protocol to quickly and reproducibly generate biologically inspired, biodegradable articifical antigen presenting cells (aAPC) with tunable size, shape, and surface protein presentation for T cell expansion ex vivo or in vivo.

Artificial antigen presenting cells (aAPC) are a promising platform for immune modulation due to their potent ability to stimulate T cells. Acellular ...

This method can help answer key questions in the amino-engineering field. Such as, what is the role of particle physical properties on biomaterial immune cell interactions and activation. The main advantage of this technique is that it enables an independent control of the size and shape of biomimetic particles.The implications of this technique extend toward the therapy of cancer as it is an off the shelf particle therapy that can cause in vivo cell mediated immune responses. Though this method can provide insight into cancer amino-therapy, it can also be applied to other systems. Such as, infectious disease or Type One diabetes.For micro-particle synthesis, begin by weighing out 100 milligrams of poly(lactic-co-glycolic acid)or PLGA, into a scintillation vial and dissolving the PLGA in five milliliters of dichloromethane by vortexing. Place a homogenizer in a beaker containing 50 milliliters of 1%polyvinyl alcohol, or PVA solution, so that the homogenizer is as close to the bottom of the beaker as possible without touching it. Turn on the homogenizer to the appropriate speed and add the PLGA solution to the beaker for one minute of homogenization.At the end of the homogenization, pour the polyvinyl alcohol PLGA micro-particle solution into a beaker containing 100 milliliters of 5%PVA solution on a stir plate in a chemical hood and stir the solution for at least four hours. When the solvent has evaporated, pour the particle solution into 50 milliliter conical tubes and collect the particles by centrifugation. Replace the supernatant in each tube with 20 milliliters of de-ionized water and re-suspend the particles by vortexing.Then bring the final volume in each tube up to 50 milliliters with fresh de-ionized water and wash the particles two more times as just demonstrated. For nano-particle synthesis, dissolve 200 milligrams of PLGA in five milliliters of dichloromethane and place a sonicator probe in a beaker containing 50 milliliters of 1%PVA solution on ice without touching the bottom of the beaker. Begin the sonication at 12 watts and immediately add the PLGA solution to the beaker for a two minute sonication to generate nano-particles with an approximate 200 nanometer diameter.After sonication, pour the 1%polyvinyl alcohol PLGA nano-particle solution into a beaker containing 100 milliliters of 5 PVA solution on a stir plate for four hours of solvent evaporation in a chemical fume hood. When all of the solvent is evaporated, pour the particle solution into 50 milliliter conical tubes for centrifugation to remove any micro-particles and remove the supernatants. Then transfer the nano-particles into high speed centrifuge tubes for three washes in de-ionized water as demonstrated.For polymeric particle fabrication, after the last wash, re-suspend the particles in approximately one milliliter of fresh de-ionized water and add film casting solution to the particles to a final concentration of 2.5 milligrams per milliliter particles. Transfer the particle suspension in 10 milliliter aliquots into 75 by 50 millimeter rectangular Petri dishes for one dimensional stretching. Or in 15 milliliter aliquots into 100 by 100 millimeter square Petri dishes for two dimensional stretching.After overnight drying in a chemical hood, use tweezers to remove the films and trim the edges with scissors. For 1D stretching, place the two short edges of one film between two pieces of neoprene rubber for mounting onto the aluminum blocks of one axis of an automated thin film stretching device. Then use an Allen wrench to screw the metal grips on top of the rubber to hold the film in place.For 2D stretching, mount all four edges onto four aluminum blocks to stretch the film on both axes measure and record the length of film in between the aluminum blocks on one axis for one D stretching or both axes for 2D stretching and calculate the distance required to stretch the film in one or two directions based on the desired fold stretch. Then place the film loaded stretching device in an oven at 90 degrees Celsius next to a larger beaker of a small amount of water to bring the film to temperature over 10 minutes. When the stretching is complete, let the film cool to room temperature for 20 minutes.For 1D stretching, cut the film out of the stretching device at the edges. For 2D stretching, cut out and save the center square of film that is uniformly stretched on both axes. Place the films in 50 milliliter conical tubes with no more than two films per tube and add approximately 25 milliliters of de-ionized water to each tube for vortexing.When the films have dissolved, wash the particles three times in de-ionized water as demonstrated. Re-suspending the particles in approximately one milliliter of fresh de-ionized water per tube after the last wash. Then freeze the particles at minus 80 degrees Celsius for one hour or overnight lyophilization.The next morning, re-suspend the lyophilized micro or nano-particles at 20 milligrams per milliliter in freshly prepared MES buffer with vortexing. Add 100 microliters of the particle solution to a polypropylene micro centrifuge tube containing 900 microliters of MES buffer and add 100 microliters of freshly prepared EDC NHS solution. Mix the particles by vortexing and incubate the particles on an inverter at room temperature for 30 minutes.At the end of the incubation, collect the particles by centrifugation and re-suspend the micro-particle pellets in one milliliter of PBS by vortexing or re-suspend the nano-particles in one milliliter of PBS by five seconds of sonication at two to three watts. Next, add eight micrograms of a suitable signal one protein and 10 micrograms of anti mouse CD28 antibody to the micro-particles, or 16 micrograms of the signal one protein and 20 micrograms of anti mouse CD28 to the nano-particles. Bring the final volume in each tube to 1.1 milliliter with PBS and incubate the particles overnight on an inverter at four degrees Celsius.The next day, wash the particles three times in de-ionized water as demonstrated. These PLGA nano and micro-particles were synthesized using the single emulsion techniques as demonstrated and imaged using transmission and scanning electron microscopy. After homogenization, the micro-particles demonstrated an average diameter of about three micrometers.The spherical micro-particles had an aspect ration of about one, while the 1D stretched prolate ellipsoidal particles had a larger aspect ratio of about three and a half and the 2D stretched oblate ellipsoidal particles had an aspect ratio of about 1.2, roughly maintaining an aspect ratio of one. Conjugation efficiency results reveal the similar amounts of protein on the surface of spherical and ellipsoidal micro-artificial antigen presenting cells, or AAPC and nano-AAPC, demonstrating that protein coupling during AAPC synthesis occurs in a concentration dependent manner. Prolate ellipsoidal AAPC were found to induce higher levels of T cell proliferation at sub-saturating doses than spherical AAPC with the best separation achieved at a 01 milligram dose.After seven days, manual counting of the T cells revealed that prolate ellipsoidal AAPC more effectively stimulate T cells compared to their spherical counterparts at the micro and nano scale in a dose dependent manner. Following this procedure, AAPC can be administrated in vivo to gauge their therapeutic efficacy and pharmacokinetics. After its development, this technique helped pave the way for researchers in the field of immuno-engineering to explore the effect of anisotropy on AAPC efficacy.

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7.7K 次观看.  Johns Hopkins University School of Medicine. 此方法有助于回答氨基工程领域的关键问题。例如，粒子物理特性对生物材料免疫细胞相互作用和活化的作用是什么？这种技术的主要优点是它能够独立控制仿生粒子的大小和形状。这种技术的影响延伸到癌症的治疗，因为它是一种现成的粒子疗法，可导致体内细胞内调节的免疫反应。虽然这种方法可以提供癌症氨基治疗的见解，它也可以应用于其他系统。如，传染病?...