F.L.Q. appreciates the support by supported by the Pioneer R&#38;D Program of Zhejiang (2022C03031), the National Key Research and Development Program of China (2021YFA0910103), the National Natural Science Foundation of China (22274141, 22074080), the Natural Science Foundation of Shandong Province (ZR2022ZD28) and the Taishan Scholar Program of Shandong Province (tsqn201909106). H.C. acknowledges the financial support from the National Natural Science Foundation of China (82202329). The authors acknowledge the use of instruments at the Shared Instrumentation Core Facility at the Hangzhou Institute of Medicine (HIM), Chinese Academy of Sciences.

This study does not require ethical clearance as the pig skin used for the experiments described in section 3 was purchased as edible pig ears from the market and not sourced from experimental animals.
1. Isolation of exosomes
<ol>
	<li>Cell culture
	<ol>
		<li>Cultivate mouse ovarian epithelial cancer cells ID8 in Dulbecco&#39;s Modified Eagle Medium (DMEM) culture medium containing 10% fetal bovine serum and 1% penicillin-streptomycin solution (100&#215;) (see Tabl...

Microneedle Patches for Sustained Delivery of Exosomes in Biomedical Applications

<ol>
	<li>Barile, L., Vassalli, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exosomes:+Therapy+delivery+tools+and+biomarkers+of+diseases.">Exosomes: Therapy delivery tools and biomarkers of diseases.</a> Pharmacol Ther. 174, 63-78 (2017).</li><li>Kalluri, R., Lebleu, V. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+biology,+function,+and+biomedical+applications+of+exosomes.">The biology, function, and biomedical applications of exosomes.</a> Science. 367 (640), eaau6977 (2020).</li><li>Mathieu, M., Martin-Jaular, L., Lavieu, G., Thery, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specificities+of+secretion+and+uptake+of+exosomes+and+other+extracellular+vesicles+for+cell-to-cell+communication.">Specificities of secretion and uptake of exosomes and other extracellular vesicles for cell-to-cell communication.</a> Nat Cell Biol. 21 (1), 9-17 (2019).</li><li>Nair, 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=Hybrid+nanoparticle+system+integrating+tumor-derived+exosomes+and+poly(amidoamine)+dendrimers:+Implications+for+an+effective+gene+delivery+platform.">Hybrid nanoparticle system integrating tumor-derived exosomes and poly(amidoamine) dendrimers: Implications for an effective gene delivery platform.</a> Chem Mater. 35 (8), 3138-3150 (2023).</li><li>Lu, Z., 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=Dendritic+cell-derived+exosomes+elicit+tumor+regression+in+autochthonous+hepatocellular+carcinoma+mouse+models.">Dendritic cell-derived exosomes elicit tumor regression in autochthonous hepatocellular carcinoma mouse models.</a> J Hepatol. 67 (4), 739-748 (2017).</li><li>Oskouie, M. N., Aghili Moghaddam, N. S., Butler, A. E., Zamani, P., Sahebkar, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Therapeutic+use+of+curcumin-encapsulated+and+curcumin-primed+exosomes.">Therapeutic use of curcumin-encapsulated and curcumin-primed exosomes.</a> J Cell Physiol. 234 (6), 8182-8191 (2019).</li><li>Yuan, 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=Macrophage+exosomes+as+natural+nanocarriers+for+protein+delivery+to+inflamed+brain.">Macrophage exosomes as natural nanocarriers for protein delivery to inflamed brain.</a> Biomaterials. 142, 1-12 (2017).</li><li>Liao, W., 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=Exosomes:+The+next+generation+of+endogenous+nanomaterials+for+advanced+drug+delivery+and+therapy.">Exosomes: The next generation of endogenous nanomaterials for advanced drug delivery and therapy.</a> Acta Biomater. 86, 1-14 (2019).</li><li>Zhu, X., 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=Comprehensive+toxicity+and+immunogenicity+studies+reveal+minimal+effects+in+mice+following+sustained+dosing+of+extracellular+vesicles+derived+from+hek293t+cells.">Comprehensive toxicity and immunogenicity studies reveal minimal effects in mice following sustained dosing of extracellular vesicles derived from hek293t cells.</a> J Extracell Vesicles. 6 (1), 1324730 (2017).</li><li>Wen, 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=Biodistribution+of+mesenchymal+stem+cell-derived+extracellular+vesicles+in+a+radiation+injury+bone+marrow+murine+model.">Biodistribution of mesenchymal stem cell-derived extracellular vesicles in a radiation injury bone marrow murine model.</a> Int J Mol Sci. 20 (21), 5468-5482 (2019).</li><li>Cheng, Y., Zeng, Q., Han, Q., Xia, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+pH,+temperature+and+freezing-thawing+on+quantity+changes+and+cellular+uptake+of+exosomes.">Effect of pH, temperature and freezing-thawing on quantity changes and cellular uptake of exosomes.</a> Protein Cell. 10 (4), 295-299 (2019).</li><li>Jana, B. A., Shivhare, P., Srivastava, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gelatin-PVP+dissolving+microneedle-mediated+therapy+for+controlled+delivery+of+nifedipine+for+rapid+antihypertension+treatment.">Gelatin-PVP dissolving microneedle-mediated therapy for controlled delivery of nifedipine for rapid antihypertension treatment.</a> Hypertens Res. 47 (2), 427-434 (2024).</li><li>Zheng, Y., 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=A+rapidly+dissolvable+microneedle+patch+with+tip-accumulated+antigens+for+efficient+transdermal+vaccination.">A rapidly dissolvable microneedle patch with tip-accumulated antigens for efficient transdermal vaccination.</a> Macromol Biosci. 23 (12), e2300253 (2023).</li><li>Huang, 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=Efficient+delivery+of+nucleic+acid+molecules+into+skin+by+combined+use+of+microneedle+roller+and+flexible+interdigitated+electroporation+array.">Efficient delivery of nucleic acid molecules into skin by combined use of microneedle roller and flexible interdigitated electroporation array.</a> Theranostics. 8 (9), 2361-2376 (2018).</li><li>Zhou, Z., 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=Reverse+immune+suppressive+microenvironment+in+tumor+draining+lymph+nodes+to+enhance+anti-pd1+immunotherapy+via+nanovaccine+complexed+microneedle.">Reverse immune suppressive microenvironment in tumor draining lymph nodes to enhance anti-pd1 immunotherapy via nanovaccine complexed microneedle.</a> Nano Res. 13 (6), 1509-1518 (2020).</li><li>Kim, Y. C., Park, J. H., Prausnitz, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microneedles+for+drug+and+vaccine+delivery.">Microneedles for drug and vaccine delivery.</a> Adv Drug Deliv Rev. 64 (14), 1547-1568 (2012).</li><li>Bui, V. 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=Dissolving+microneedles+for+long-term+storage+and+transdermal+delivery+of+extracellular+vesicles.">Dissolving microneedles for long-term storage and transdermal delivery of extracellular vesicles.</a> Biomaterials. 287, 121644 (2022).</li><li>Nir, Y., Potasman, I., Sabo, E., Paz, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fear+of+injections+in+young+adults:+Prevalence+and+associations.">Fear of injections in young adults: Prevalence and associations.</a> Am J Trop Med Hyg. 68 (3), 341-344 (2003).</li><li>Zhang, Y., Jiang, G., Yu, W., Liu, D., Xu, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microneedles+fabricated+from+alginate+and+maltose+for+transdermal+delivery+of+insulin+on+diabetic+rats.">Microneedles fabricated from alginate and maltose for transdermal delivery of insulin on diabetic rats.</a> Mater Sci Eng C Mater Biol Appl. 85, 18-26 (2018).</li><li>Roy, G., Garg, P., Venuganti, V. V. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microneedle+scleral+patch+for+minimally+invasive+delivery+of+triamcinolone+to+the+posterior+segment+of+eye.">Microneedle scleral patch for minimally invasive delivery of triamcinolone to the posterior segment of eye.</a> Int J Pharm. 612, 121305 (2022).</li><li>Creighton, R. L., Woodrow, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microneedle-mediated+vaccine+delivery+to+the+oral+mucosa.">Microneedle-mediated vaccine delivery to the oral mucosa.</a> Adv Healthc Mater. 8 (4), 1801180 (2019).</li><li>Hu, S., Zhu, D., Li, Z., Cheng, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detachable+microneedle+patches+deliver+mesenchymal+stromal+cell+factor-loaded+nanoparticles+for+cardiac+repair.">Detachable microneedle patches deliver mesenchymal stromal cell factor-loaded nanoparticles for cardiac repair.</a> ACS Nano. 16 (10), 15935-15945 (2022).</li><li>Yang, W., Zheng, H., Lv, W., Zhu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+status+and+prospect+of+immunotherapy+for+colorectal+cancer.">Current status and prospect of immunotherapy for colorectal cancer.</a> Int J Colorectal Dis. 38 (1), 266-276 (2023).</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=Methods+and+technologies+for+exosome+isolation+and+characterization.">Methods and technologies for exosome isolation and characterization.</a> Small Methods. 2 (9), 1800021 (2018).</li><li>Bosch, 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=Trehalose+prevents+aggregation+of+exosomes+and+cryodamage.">Trehalose prevents aggregation of exosomes and cryodamage.</a> Sci Rep. 6, 36162 (2016).</li><li>Bhattacharyya, M., Jariyal, H., Srivastava, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hyaluronic+acid:+More+than+a+carrier,+having+an+overpowering+extracellular+and+intracellular+impact+on+cancer.">Hyaluronic acid: More than a carrier, having an overpowering extracellular and intracellular impact on cancer.</a> Carbohydr Polym. 317, 121081 (2023).</li><li>Chang, 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=Cryomicroneedles+for+transdermal+cell+delivery.">Cryomicroneedles for transdermal cell delivery.</a> Nat Biomed Eng. 5 (9), 1008-1018 (2021).</li></ol>

H. C., F.L.Q, and S.J.M are inventors in a patent application that has been filed based on the data in this manuscript. H.C. is the scientific founder of Medcraft Biotech. Inc.

Currently, the main methods for isolating exosomes include ultracentrifugation, density-gradient centrifugation, ultrafiltration, precipitation, immunoaffinity magnetic beads, and microfluidics24. Due to the limited loading capacity of microneedles caused by their small needle tip space, it is necessary to increase the concentration of exosomes to load more. Therefore, we chose ultrafiltration to concentrate the cell culture supernatant and then used ultracentrifugation to isolate the exosomes. Th...

Exosomes, which are small vesicles released by cells into the extracellular matrix, have been proposed as potential biotherapeutics and drug delivery vectors for the treatment of several diseases and cancers1. During their biogenesis process, exosomes encapsulate various biologically active molecules from within the cells, including functional proteins and nucleic acids2. As a result, when taken up by recipient cells during the transport process, exosomes have the ability to modulate gene expression and cellular functions in the target cells3. As a kind of natural information messenger, exosomes have been fully taken advantage of in tissue regeneration, immune regulation, and as a delivery carrier4. Through engineering techniques, specific ligands can be enriched on the surface of exosomes, enabling the induction or inhibition of signaling events in recipient cells or targeting specific cell types5. Chemotherapeutic agents can also be loaded into exosomes for cancer treatment6. Moreover, exosomes have the ability to cross the blood-brain barrier for therapeutic cargo delivery, making them highly promising for the treatment of brain disorders7. Compared to liposomes, exosomes exhibit enhanced cellular uptake and improved biocompatibility8. They are capable of efficiently entering other cells while demonstrating better tolerance and lower toxicity9. However, the traditional bolus injection of exosomes is prone to sequestration and rapid clearance by the liver, kidneys, and spleen in the bloodstream10. Moreover, exosomes have poor stability in vitro and are susceptible to storage conditions, which restrict their clinical applications11.
Microneedles, an array of micrometric-sized needle tips, have the capability to penetrate physiological barriers for the delivery of small molecule drugs12, proteins13, nucleic acids14, and nanomedicines15. Microneedles are precisely engineered to target lesions on the skin surface, and their dispersed tips ensure uniform drug distribution at the targeted site, thus amplifying their therapeutic impact16. The design and material composition of microneedles facilitate&#160;the dry storage of bioactive substances such as proteins and nucleic acids, enhancing their stability17. Traditional injection methods have a relatively short duration of action and can cause pain, inducing fear in patients18. The micrometer-sized length of microneedle minimizes tissue trauma and prevents nerve stimulation, thereby eliminating pain and improving patient compliance19. Additionally, the user-friendly nature of microneedles allows patients to self-administer the treatment without the need for specialized personnel16. In addition to the skin, microneedles can also be used in tissues such as the eyes20, oral mucosa21, heart22, and blood vessels23. The application of microneedles for the clinical delivery of exosomes provides a promising and prospective strategy.
Hence, we introduce an exosome-loaded microneedle (exo@MN) patch and disclose its fabrication method. The microneedle patches were fabricated using a two-step casting method, along with centrifugation and vacuum drying, which promotes the aggregation of exosomes at the microneedle tips, thereby enhancing delivery efficiency. Both the needle tips and backing were constructed using materials that exhibit excellent biocompatibility and water solubility. Trehalose and hyaluronic acid (HA) were incorporated as tip materials to provide protection for the exosomes, and polyvinylpyrrolidone (PVP) dissolved in absolute ethanol was chosen as the backing material. The morphology of the microneedle patch was characterized using microscopy and scanning electron microscope&#160;(SEM). The mechanical testing of the microneedle was assessed using a tensile meter to confirm their capability to penetrate the skin, and the release rate on pig skin was investigated to be 60 s. Furthermore, the morphology, size, and protein content of both fresh exosomes and exosomes in exo@MN were characterized using transmission electron microscope&#160;(TEM), nanoparticle tracking analysis (NTA), and western blotting (WB). The internalization of exosomes by dendritic cells (DCs) was characterized using confocal laser scanning microscope&#160;(CLSM), and the maturation of DCs was evaluated through flow cytometry. The morphological characterization and biological functions of the two types of exosomes are essentially consistent.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>100x penicillin-streptomycin solutions</td>
			<td>Jrunbio Scientific</td>
			<td>MA0110</td>
			<td>Cell culture</td>
		</tr>
		<tr>
			<td>180 kDa pre-stained protein marker</td>
			<td>Thermo</td>
			<td>26616</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>3% Uranyl acetate</td>
			<td>Henan Ruixin Experimental Supplies</td>
			<td>GZ02625</td>
			<td>Morphological characterization of exosomes</td>
		</tr>
		<tr>
			<td>3D printer</td>
			<td>BMF technology</td>
			<td>nanoArch S130</td>
			<td>Mold preparation</td>
		</tr>
		<tr>
			<td>4%&#8211;20% precast gel</td>
			<td>Genscript</td>
			<td>ExpressPlus PAGE GEL</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>5&#215; SDS-PAGE loading buffer</td>
			<td>Titan</td>
			<td>04048254</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>Anti-mouse Alix antibody</td>
			<td>Biolegend</td>
			<td>12422-1-AP</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>Anti-mouse CD63 antibody</td>
			<td>Biolegend</td>
			<td>ab217345</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>APC anti-mouse CD80 antibody</td>
			<td>Biolegend</td>
			<td>104713</td>
			<td>Antibody</td>
		</tr>
		<tr>
			<td>Auto fine coater</td>
			<td>ZIZHU</td>
			<td>JBA5-100</td>
			<td>Morphological characterization of microneedle</td>
		</tr>
		<tr>
			<td>BCA assay kit</td>
			<td>Beyotime</td>
			<td>P0012</td>
			<td>Protein concentration assay</td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Thermo Fisher</td>
			<td>Muitifuge X1R pro</td>
			<td>Cell centrifuge</td>
		</tr>
		<tr>
			<td>Circulating water vacuum pump</td>
			<td>Yuhua Instrument</td>
			<td>SHZ-D(III)</td>
			<td>Filtration</td>
		</tr>
		<tr>
			<td>CO2 incubator</td>
			<td>Eppendorf</td>
			<td>CellXpert C170</td>
			<td>Cell culture</td>
		</tr>
		<tr>
			<td>Confocal laser scanning microscope</td>
			<td>Nikon</td>
			<td>A1HD25</td>
			<td>Fluorescence imaging</td>
		</tr>
		<tr>
			<td>Copper mesh</td>
			<td>Beijing Zhongjingkeyi Technology&#160;</td>
			<td>JF-ZJKY/300</td>
			<td>Morphological characterization of exosomes</td>
		</tr>
		<tr>
			<td>D- (+) -Trehalose dihydrate</td>
			<td>Aladdin</td>
			<td>5138-23-4</td>
			<td>Fabrication of microneedle&#160;</td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s modified Eagle&#8217;s medium</td>
			<td>Meilunbio</td>
			<td>MA0212</td>
			<td>Cell culture</td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s phosphate-buffered saline</td>
			<td>Meilunbio</td>
			<td>MA0010</td>
			<td>Cell culture</td>
		</tr>
		<tr>
			<td>Electrophoresis system</td>
			<td>Bio-rad</td>
			<td>PowerPac-basic</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>Jrunbio Scientific</td>
			<td>JR100</td>
			<td>Cell culture</td>
		</tr>
		<tr>
			<td>FITC anti-mouse CD11c antibody</td>
			<td>Biolegend</td>
			<td>117305</td>
			<td>Antibody</td>
		</tr>
		<tr>
			<td>Flow cytometry</td>
			<td>BD</td>
			<td>LSR Fortessa</td>
			<td>Fluorescence detection</td>
		</tr>
		<tr>
			<td>Gel imager</td>
			<td>Cytiva</td>
			<td>Amersham ImageQuant 800</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>HRP-conjugated anti-rabbit IgG</td>
			<td>CST</td>
			<td>7074S</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>HTL resin</td>
			<td>BMF technology</td>
			<td></td>
			<td>Mold preparation</td>
		</tr>
		<tr>
			<td>Hyaluronic acid (MW = 300 kDa)</td>
			<td>Bloomage Biotechnology</td>
			<td>9004-61-9</td>
			<td>Fabrication of microneedle&#160;</td>
		</tr>
		<tr>
			<td>Immersion oil</td>
			<td>Nikon</td>
			<td>MXA22168</td>
			<td>Fluorescence imaging</td>
		</tr>
		<tr>
			<td>Ion cleaner</td>
			<td>JEOL</td>
			<td>EC-52000IC</td>
			<td>Morphological characterization of exosomes</td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Olympus</td>
			<td>CKX53</td>
			<td>Observe the microneedle tip dissolving process</td>
		</tr>
		<tr>
			<td>Mouse ovarian epithelial cancer cell ID8</td>
			<td>MeisenCTCC</td>
			<td>&#160;CC90105</td>
			<td>Cell culture</td>
		</tr>
		<tr>
			<td>Nanoparticle tracking analysis</td>
			<td>Particle Metrix</td>
			<td>ZetaView</td>
			<td>Size analysis of exosomes</td>
		</tr>
		<tr>
			<td>Pacific Blue anti-mouse I-A/I-E antibody</td>
			<td>Biolegend</td>
			<td>107619</td>
			<td>Antibody</td>
		</tr>
		<tr>
			<td>Phenylmethanesulfonyl fluoride</td>
			<td>Beyotime</td>
			<td>ST507</td>
			<td>Protease inhibitors</td>
		</tr>
		<tr>
			<td>Plasma cleaner</td>
			<td>Hefei Kejing Material Technology</td>
			<td>PDC-36G</td>
			<td>Fabrication of microneedle&#160;</td>
		</tr>
		<tr>
			<td>Polydimethylsiloxane</td>
			<td>Dow Corning</td>
			<td>9016-00-6</td>
			<td>Mold preparation</td>
		</tr>
		<tr>
			<td>Polyvinylpyrrolidone (MW = 40 kDa)</td>
			<td>Aladdin</td>
			<td>9003-39-8</td>
			<td>Fabrication of microneedle&#160;</td>
		</tr>
		<tr>
			<td>Prism&#160;</td>
			<td>GraphPad</td>
			<td>Version 9</td>
			<td>Statistical analysis</td>
		</tr>
		<tr>
			<td>PVDF membrane</td>
			<td>Millipore</td>
			<td>IPVH00010</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>Quick-snap centrifuge</td>
			<td>Beckman</td>
			<td>344619</td>
			<td>Exosomes extraction</td>
		</tr>
		<tr>
			<td>RIPA lysis buffer</td>
			<td>Applygen</td>
			<td>C1053</td>
			<td>Lysis membrane</td>
		</tr>
		<tr>
			<td>Roswell park memorial institute 1640</td>
			<td>Meilunbio</td>
			<td>MA0548</td>
			<td>Cell culture</td>
		</tr>
		<tr>
			<td>Scanning electron microscope</td>
			<td>JEOL</td>
			<td>JSM-IT800</td>
			<td>Morphological characterization of microneedle</td>
		</tr>
		<tr>
			<td>Stereo microscope</td>
			<td>Olympus</td>
			<td>SZX16</td>
			<td>Characterization of morphology</td>
		</tr>
		<tr>
			<td>Super ECL detection reagent</td>
			<td>Applygen</td>
			<td>P1030</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>Tensile meter</td>
			<td>Instron</td>
			<td>68SC-05</td>
			<td>Mechanical testing</td>
		</tr>
		<tr>
			<td>Transmission electron microscope</td>
			<td>JEOL</td>
			<td>JEM-2100plus</td>
			<td>Morphological characterization of exosomes</td>
		</tr>
		<tr>
			<td>Tris buffered saline</td>
			<td>Sangon Biotech</td>
			<td>JF-A500027-0004</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>Tween-20</td>
			<td>Beyotime</td>
			<td>ST825</td>
			<td>Western blotting</td>
		</tr>
		<tr>
			<td>Ultracentrifuge</td>
			<td>Beckman</td>
			<td>Optima XPN-100</td>
			<td>Exosomes extraction</td>
		</tr>
		<tr>
			<td>Ultrafiltration tube</td>
			<td>Millipore</td>
			<td>UFC910096</td>
			<td>Exosomes concentration</td>
		</tr>
		<tr>
			<td>Vacuum drying oven</td>
			<td>Shanghai Yiheng Technology</td>
			<td>DZF-6024</td>
			<td>Fabrication of microneedle</td>
		</tr>
		<tr>
			<td>Vacuum filtration system</td>
			<td>Biosharp</td>
			<td>BS-500-XT</td>
			<td>Filtration</td>
		</tr>
	</tbody>
</table>

fabrication and characterization of microneedle patches for loading and delivery of exosomes

Exosomes, as emerging &#34;next-generation&#34; biotherapeutics and drug delivery vectors, hold immense potential in diverse biomedical fields, ranging from drug delivery and regenerative medicine to disease diagnosis and tumor immunotherapy. However, the rapid clearance by traditional bolus injection and poor stability of exosomes restrict their clinical application. Microneedles serve as a solution that prolongs the residence time of exosomes at the administration site, thereby maintaining the drug concentration and facilitating sustained therapeutic effects. In addition, microneedles also possess the ability to maintain the stability of bioactive substances. Therefore, we introduce a microneedle patch for loading and delivering exosomes and share the methods, including isolation of exosomes, fabrication, and characterization of exosome-loaded microneedle patches. The microneedle patches were fabricated using trehalose and hyaluronic acid as the tip materials and polyvinylpyrrolidone as the backing material through a two-step casting method. The microneedles demonstrated robust mechanical strength, with tips able to withstand 2 N. Pig skin was used to simulate human skin, and the tips of microneedles completely melted within 60 s after skin puncture. The exosomes released from the microneedles exhibited morphology, particle size, marker proteins, and biological functions comparable to those of fresh exosomes, enabling dendritic cells uptake and promoting their maturation.

Author Spotlight: Innovative Microneedle-Based Strategies for Enhanced Exosome Delivery and Stability

Fabrication and Characterization of Microneedle Patches for Loading and Delivery of Exosomes

My research focused on the efficient development of exosomes, the development of the microneedle strategy can increase exsome stability, enhance provide more possibility for the clinical application of exosomes. We will successfully develop the for advanced microneedle delivery systems. Those include self-healing porous microneedles for sustained drug delivery, ultrasound microneedle device for rapid loading and delivery of drugs, and cryomicroneedles for delivery of living cell, and sugar microneedles for delivery of exosomes.We use microneedle to pierce the biological barrier and then deliver exocells directly to the vector area efficiently. By storing them dry, we enhance their stability, making them precise, easy, and convenient for both clinical and home use. My lab, we focused on key technologies for developing the advanced microneedle-based delivery systems and that can load and deliver various therapeutics.Includes MRA, small molecular drug, antibodies, cell, and exosome. We are also investigate their chemical and physical properties and therapeutic efficacy in different biomedical applications.

Here, we present a protocol for the isolation of exosomes, fabrication and characterization of exo@MN patch. Figure 1 illustrates the process flowchart for the fabrication of exo@MN patch. The exosomes were mixed with trehalose and HA, and the mixture was then added to the microneedle mold and centrifuged. This process facilitated the aggregation of exosomes at the needle tips, promoting rapid release. After drying, PVP solution was added and centrifuged to fill the mold completely. Upon com...

Exosomes possess significant clinical potential, but their practical application is limited due to easy in vivo clearance and poor stability. Microneedles present a solution by enabling localized delivery by puncturing physiological barriers and dry-state preservation, thereby addressing the limitations of exosome administration and expanding their clinical utility.

Exosomes, as emerging &#34;next-generation&#34; biotherapeutics and drug delivery vectors, hold immense potential in diverse biomedical fields, ranging ...

fabrication-characterization-microneedle-patches-for-loading-delivery

Research

JoVE Journal

Bioengineering

617 vistas.  Tianjin University. Mi investigación se centró en el desarrollo eficiente de exosomas, el desarrollo de la estrategia de microagujas puede aumentar la estabilidad del exosoma, mejorar y proporcionar más posibilidades para la aplicación clínica de exosomas. Desarrollaremos con éxito los sistemas avanzados de administración de microagujas. Entre ellas se encuentran las microagujas porosas autorreparables para la administración sostenida de fármacos, el dispositivo de micr...