Name: Fabrication of Dissolvable Microneedle Patches Loaded with α-Lactalbumin Nanomicelles for Transdermal Capsaicin Delivery and Adipose Tissue Reduction (Video) | JoVE Journal
Uploaded: 2025-12-30T14:03:00.000+00:00
Duration: 6 min 33 s
Description: Learn to fabricate dissolvable microneedle patches loaded with α-lactalbumin nanomicelles for transdermal capsaicin delivery. This method enables targeted adipose tissue reduction in obesity research.

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5 minutes

This project was supported by the Young Scientists Fund of the National Natural Science Foundation of China (No. 32202024), the Young Scientists Fund of Shandong Provincial Natural Science Foundation (No. ZR2024QC103), the Key Research and Development Plan of Shandong Province (2025CXGC010803, 2022CXPT022), the Shandong Province Poultry Industry Technology System (SDAIT-11-10), and the Universities-Industry Collaboration Program funded by the Bureau of Education of Yantai City, China (Development of Next-Generation Vaccines Platform for Pet Animals).

All animal experiments were performed in accordance with the Guide for the Care and Use of Laboratory Animals and were approved by the Science and Technology Ethics Review Committee of Ludong University (Approval No. LDU-IRB2025020011). The reagents and&#160;equipment used are listed in the Table of Materials.
1. Preparation of &#945;-Lactalbumin nanomicelles encapsulating capsaicin 12
<ol>
	<li>Dissolve &#945;-lactalbumin in deionized water to a concentration of 6 mg/mL and adjust the pH to 7.4. Stir the solution using a magnetic stirrer at 8-28 &#215; g until &#945;-lactalbumin is completely dissolved (typically 20-30 min).</li>
	<li>Add Bacillus licheniformis protease (BLP) at an enzyme-to-substrate ratio of 1:100 (w/w).</li>
	<li>Incubate the mixture at 50 &#176;C for 30 min to generate amphiphilic peptides.</li>
	<li>Terminate the reaction by heating the solution to 95 &#176;C for 5 min, then cool to room temperature and filter through a 0.22 &#181;m membrane.</li>
	<li>Dissolve capsaicin in ethanol to a concentration of 1 mg/mL. Add the capsaicin solution dropwise into the peptide solution under gentle stirring.</li>
	<li>Continue stirring for 2 h to allow self-assembly of nanomicelles.</li>
	<li>Remove free capsaicin by dialyzing the mixture (MWCO 3.5 kDa) against deionized water for 12 h, replacing the water every 4 h.</li>
	<li>Freeze-dry (lyophilize) the prepared &#945;-lactalbumin nanomicelles.</li>
	<li>Characterize the nanomicelles using TEM, DLS, and zeta potential analysis.</li>
</ol>
2. Fabrication of dissolvable microneedle patches 11
<ol>
	<li>Prepare the polymer solution by dissolving HA (5% w/v) and PVA (5% w/v) in deionized water at 60 &#176;C and stirring until the solution becomes clear.</li>
	<li>Cool the polymer solution to room temperature and mix it with the capsaicin-loaded nanomicelles (M(Cap)) at a 4:1 ratio.</li>
	<li>Degas the mixture under vacuum in a desiccator connected to a vacuum pump (approximately &#8722;80 kPa) for 10 min to remove air bubbles before casting into PDMS molds.</li>
	<li>Load 200 &#181;L of the mixture into PDMS molds (10 &#215; 10 needle array, 600 &#181;m height).</li>
	<li>Centrifuge the molds at 1800 &#215; g at RT for 10 min to ensure complete filling of the microneedle cavities.</li>
	<li>Repeat the filling once, followed by a second centrifugation under the same conditions as in step 2.5, and then dry the molds under vacuum (approximately &#8722;80 kPa) at room temperature for 12 h.</li>
	<li>Carefully peel the microneedle patches from the molds.</li>
	<li>Examine microneedle morphology by SEM.</li>
</ol>
3. Mechanical testing of microneedles 19
<ol>
	<li>Place the microneedle patch on the stage of a texture analyzer with the needles facing upward.</li>
	<li>Compress the patch using a probe at a speed of 20 &#181;m/s until a displacement of 0.7 mm is reached.</li>
	<li>Record the fracture force and confirm that it is &#8805;0.15 N per needle to ensure skin penetration capability.</li>
</ol>
4. In vitro insertion and dissolution test 11
<ol>
	<li>Shave the abdominal skin of mice and excise the skin for ex vivo testing.</li>
	<li>Place the excised skin on an agarose gel support.</li>
	<li>Press the microneedle patch firmly onto the skin for 30 s.</li>
	<li>Maintain contact between the patch and the skin for 30 min.</li>
	<li>Observe needle dissolution.</li>
	<li>Stain the skin with H&#38;E staining and visualize insertion sites under CLSM.</li>
</ol>
5. In vitro release study 11
<ol>
	<li>Immerse microneedle patches in PBS buffer (pH 6.5 or 7.4) at 37 &#176;C.</li>
	<li>At defined intervals, withdraw buffer samples and immediately replenish with an equal volume of fresh buffer.</li>
	<li>Determine the capsaicin concentration in the collected samples using HPLC.</li>
	<li>Compare the release profiles at different pH conditions using HPLC.</li>
</ol>
6. In vivo application in HFD-induced obese mice 11
<ol>
	<li>Induce obesity in C57BL/6N mice by feeding a high-fat diet (HFD, 60% kcal from fat) for 8 weeks.</li>
	<li>Randomly divide the mice into five groups: normal control, HFD control, blank micelle microneedle patch (MP-M), capsaicin-loaded nanomicelle injection (InJ-M(Cap)), and capsaicin-loaded nanomicelle microneedle patch (MP-M(Cap)) groups.</li>
	<li>Depilate the inguinal region of each mouse.</li>
	<li>Anesthetize mice with inhaled isoflurane using a multi-channel small-animal anesthesia machine equipped with an anesthetic gas scavenging and filtration system. Apply one microneedle patch to the depilated area every 2 days for 28 days, and maintain each patch in place for 30 min. 
	NOTE: Before completion of the procedure, residual anesthetic gas in the induction chamber was rapidly cleared by oxygen flushing.</li>
	<li>Record body weight and food intake every 2 days during the treatment period.</li>
	<li>Analyze whole-body fat and lean tissue composition by MRI at the end of the treatment.</li>
	<li>Assess physical activity, oxygen consumption, CO&#8322; production, and respiratory quotient (RQ) in metabolic cages according to the manufacturer&#39;s instructions.</li>
	<li>Collect iWAT, sBAT, and major organs, fix, embed, section, and stain the tissues with H&#38;E, and evaluate histological changes by light microscopy.</li>
	<li>Perform Western blotting for TRPV1, PPAR&#947;, C/EBP&#945;, UCP1, and Cyt C using standard procedures.</li>
</ol>

<ol><li>Obesity and overweight. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=%22WHO+Fact+Sheets%22">WHO Fact Sheets</a>. , World Health Organization. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight (2025).</li>
<li>Bray, G. A., Kim, K. K., Wilding, J. P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Federation%2C+W.+O.+Obesity%3A+A+chronic+relapsing+progressive+disease+process.+A+position+statement+of+the+World+Obesity+Federation%5BTitle%5D)+AND+%22Obes+Rev%22%5BJournal%5D)">Federation, W. O. Obesity: A chronic relapsing progressive disease process. A position statement of the World Obesity Federation.</a> Obes Rev. 18 (7), 715-723 (2017).</li>
<li>Hruby, A., Hu, F. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+epidemiology+of+obesity%3A+A+big+picture%5BTitle%5D)+AND+%22Pharmacoeconomics%22%5BJournal%5D)">The epidemiology of obesity: A big picture.</a> Pharmacoeconomics. 33 (7), 673-689 (2015).</li>
<li>Dietrich, M. O., Horvath, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Limitations+in+anti-obesity+drug+development%3A+The+critical+role+of+hunger-promoting+neurons%5BTitle%5D)+AND+%22Nat+Rev+Drug+Discov%22%5BJournal%5D)">Limitations in anti-obesity drug development: The critical role of hunger-promoting neurons.</a> Nat Rev Drug Discov. 11 (9), 675-691 (2012).</li>
<li>Garvey, W. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((American+Association+of+Clinical+Endocrinologists+and+American+College+of+Endocrinology+comprehensive+clinical+practice+guidelines+for+medical+care+of+patients+with+obesity%5BTitle%5D)+AND+%22Endocr+Pract%22%5BJournal%5D)">American Association of Clinical Endocrinologists and American College of Endocrinology comprehensive clinical practice guidelines for medical care of patients with obesity.</a> Endocr Pract. 22, 1-203 (2016).</li>
<li>Li, Z., Liang, S., Sun, H., Bao, C., Li, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Antilipogenesis+effect+of+rutin-loaded+liposomes+using+a+microneedle+delivery+system%5BTitle%5D)+AND+%22ACS+Appl+Mater+Interfaces%22%5BJournal%5D)">Antilipogenesis effect of rutin-loaded liposomes using a microneedle delivery system.</a> ACS Appl Mater Interfaces. 15 (47), 54294-54303 (2023).</li>
<li>Hsu, C. L., Yen, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Effects+of+flavonoids+and+phenolic+acids+on+the+inhibition+of+adipogenesis+in+3T3-L1+adipocytes%5BTitle%5D)+AND+%22J+Agric+Food+Chem%22%5BJournal%5D)">Effects of flavonoids and phenolic acids on the inhibition of adipogenesis in 3T3-L1 adipocytes.</a> J Agric Food Chem. 55 (21), 8404-8410 (2007).</li>
<li>Zhang, L. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Activation+of+transient+receptor+potential+vanilloid+type-1+channel+prevents+adipogenesis+and+obesity%5BTitle%5D)+AND+%22Circ+Res%22%5BJournal%5D)">Activation of transient receptor potential vanilloid type-1 channel prevents adipogenesis and obesity.</a> Circ Res. 100 (7), 1063-1070 (2007).</li>
<li>Zheng, J., Zheng, S., Feng, Q., Zhang, Q., Xiao, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Dietary+capsaicin+and+its+anti-obesity+potency%3A+from+mechanism+to+clinical+implications%5BTitle%5D)+AND+%22Biosci+Rep%22%5BJournal%5D)">Dietary capsaicin and its anti-obesity potency: from mechanism to clinical implications.</a> Biosci Rep. 37 (3), BSR20170286(2017).</li>
<li>Negahdari, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Therapeutic+benefits+of+rutin+and+its+nanoformulations%5BTitle%5D)+AND+%22Phytother+Res%22%5BJournal%5D)">Therapeutic benefits of rutin and its nanoformulations.</a> Phytother Res. 35 (4), 1719-1738 (2021).</li>
<li>Bao, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microneedle+patch+delivery+of+capsaicin-containing+%CE%B1-lactalbumin+nanomicelles+to+adipocytes+achieves+potent+anti-obesity+effects%5BTitle%5D)+AND+%22Adv+Funct+Mater%22%5BJournal%5D)">Microneedle patch delivery of capsaicin-containing α-lactalbumin nanomicelles to adipocytes achieves potent anti-obesity effects.</a> Adv Funct Mater. 31 (20), 2011130(2021).</li>
<li>Hu, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+construction+of+enzymolyzed+%CE%B1-lactalbumin-based+micellar+nanoassemblies+for+encapsulating+various+kinds+of+hydrophobic+bioactive+compounds%5BTitle%5D)+AND+%22Food+Funct%22%5BJournal%5D)">The construction of enzymolyzed α-lactalbumin-based micellar nanoassemblies for encapsulating various kinds of hydrophobic bioactive compounds.</a> Food Funct. 10 (12), 8263-8272 (2019).</li>
<li>Wang, Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+stability+and+bioavailability+of+curcumin-loaded+%CE%B1-lactalbumin+nanocarriers+formulated+in+functional+dairy+drink%5BTitle%5D)+AND+%22Food+Hydrocoll%22%5BJournal%5D)">The stability and bioavailability of curcumin-loaded α-lactalbumin nanocarriers formulated in functional dairy drink.</a> Food Hydrocoll. 131, 107807(2022).</li>
<li>Luo, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Adipose+tissue-targeted+drug+delivery+for+treating+obesity%3A+Current+opportunities+and+challenges%5BTitle%5D)+AND+%22Drug+Deliv%22%5BJournal%5D)">Adipose tissue-targeted drug delivery for treating obesity: Current opportunities and challenges.</a> Drug Deliv. 32 (1), 2547751(2025).</li>
<li>Patel, D., Patel, N., Parmar, M., Kaur, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Transdermal+drug+delivery+system%3A+An+overview%5BTitle%5D)+AND+%22Int+J+Toxicol+Pharmacol+Res%22%5BJournal%5D)">Transdermal drug delivery system: An overview.</a> Int J Toxicol Pharmacol Res. 1, 61-80 (2011).</li>
<li>Singh, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Single-administration+self-boosting+microneedle+patch+for+the+treatment+of+obesity%5BTitle%5D)+AND+%22Adv+Ther%22%5BJournal%5D)">Single-administration self-boosting microneedle patch for the treatment of obesity.</a> Adv Ther. 7 (9), 2400028(2024).</li>
<li>Than, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Transdermal+delivery+of+anti-obesity+compounds+to+subcutaneous+adipose+tissue+with+polymeric+microneedle+patches%5BTitle%5D)+AND+%22Small+Methods%22%5BJournal%5D)">Transdermal delivery of anti-obesity compounds to subcutaneous adipose tissue with polymeric microneedle patches.</a> Small Methods. 1 (11), 1700269(2017).</li>
<li>Nguyen, H. X., Nguyen, C. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Microneedle-mediated+transdermal+delivery+of+biopharmaceuticals%5BTitle%5D)+AND+%22Pharmaceutics%22%5BJournal%5D)">Microneedle-mediated transdermal delivery of biopharmaceuticals.</a> Pharmaceutics. 15 (1), 277(2023).</li>
<li>Chu, L. Y., Choi, S. O., Prausnitz, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Fabrication+of+dissolving+polymer+microneedles+for+controlled+drug+encapsulation+and+delivery%3A+Bubble+and+pedestal+microneedle+designs%5BTitle%5D)+AND+%22J+Pharm+Sci%22%5BJournal%5D)">Fabrication of dissolving polymer microneedles for controlled drug encapsulation and delivery: Bubble and pedestal microneedle designs.</a> J Pharm Sci. 99 (10), 4228-4238 (2010).</li>
<li>Richmond, W., Wogan, M., Isbell, J., Gordon, W. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Interstrain+differences+of+in+vitro+metabolic+stability+and+impact+on+early+drug+discovery%5BTitle%5D)+AND+%22J+Pharm+Sci%22%5BJournal%5D)">Interstrain differences of in vitro metabolic stability and impact on early drug discovery.</a> J Pharm Sci. 99 (11), 4463-4468 (2010).</li>
<li>Amini-Nik, S., Yousuf, Y., Jeschke, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Scar+management+in+burn+injuries+using+drug+delivery+and+molecular+signaling%3A+Current+treatments+and+future+directions%5BTitle%5D)+AND+%22Adv+Drug+Deliv+Rev%22%5BJournal%5D)">Scar management in burn injuries using drug delivery and molecular signaling: Current treatments and future directions.</a> Adv Drug Deliv Rev. 123, 135-154 (2018).</li>
<li>Prausnitz, M. R., Langer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Transdermal+drug+delivery%5BTitle%5D)+AND+%22Nat+Biotechnol%22%5BJournal%5D)">Transdermal drug delivery.</a> Nat Biotechnol. 26 (11), 1261-1268 (2008).</li>
</ol>

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This study demonstrates that dissolvable microneedle (MN) patches loaded with &#945;-lactalbumin nanomicelles encapsulating capsaicin (M(Cap)) can achieve localized, minimally invasive anti-obesity effects. &#945;-Lactalbumin nanomicelles efficiently encapsulated hydrophobic capsaicin, improved its aqueous dispersibility, and enhanced cellular uptake, leading to stronger inhibition of adipogenesis and more prominent mitochondrial biogenesis in 3T3-L1 adipocytes than free capsaicin. These results are consistent with previ...

Obesity has become one of the most pressing global health challenges, with prevalence rising steadily in both developed and developing countries. According to the World Health Organization, more than 650 million adults were classified as obese in 2016, and in 2022, approximately 43% of adults aged &#8805;18 years were overweight, and 16% were living with obesity1. Obesity is closely associated with metabolic syndrome, cardiovascular disease, type 2 diabetes, and several cancers, imposing substantial socioeconomic and healthcare burdens2,3. Current therapeutic strategies, including dietary restriction, exercise, pharmacotherapy, and bariatric surgery, provide only partial and often transient benefits. These approaches frequently suffer from poor patient adherence, limited long-term efficacy, high invasiveness, and undesirable adverse effects4,5. Consequently, there is an urgent need for safe, effective, and patient-compliant localized therapies for obesity management.
Natural bioactive compounds have attracted increasing interest as anti-obesity agents due to their multi-targeted actions and generally favorable safety profiles. For example, rutin, a flavonoid glycoside, exhibits anti-lipogenic and metabolic regulatory effects by suppressing adipogenic transcription factors and promoting mitochondrial biogenesis6. Capsaicin, the pungent component of chili peppers, has been reported to enhance energy expenditure, induce browning of white adipose tissue, and inhibit lipid accumulation via activation of transient receptor potential vanilloid 1 (TRPV1) signaling7,8. However, the clinical translation of these compounds is hindered by poor aqueous solubility, low oral bioavailability, rapid metabolism, and, in the case of capsaicin, gastrointestinal irritation upon ingestion9.
Nanotechnology-based drug delivery systems offer promising solutions to these limitations. Liposomes, polymeric nanoparticles, and protein-based nanocarriers can markedly improve drug solubility, stability, and cellular uptake10. In particular, &#945;-lactalbumin, a food-derived milk protein, can be partially hydrolyzed into amphiphilic peptides that self-assemble into nanomicelles capable of encapsulating hydrophobic molecules such as capsaicin11. These &#945;-lactalbumin nanostructures have been shown to enhance the solubility, stability, and bioavailability of diverse hydrophobic bioactives in food and pharmaceutical matrices12,13. Nevertheless, systemic administration of nanocarriers can still lead to off-target tissue distribution and potential systemic toxicity14.
Microneedle (MN) technology has emerged as a minimally invasive, patient-friendly platform for transdermal drug delivery. Dissolvable MNs prepared from biocompatible polymers such as hyaluronic acid (HA) and polyvinyl alcohol (PVA) can painlessly penetrate the stratum corneum, dissolve after insertion, and enable precise local drug deposition in targeted tissues15,16. Combining nanocarriers with MNs further increases drug accumulation in subcutaneous adipose tissue while reducing systemic exposure and side effects17. Importantly, dissolving HA- and PVA-based MN patches are being advanced toward clinical use for transdermal delivery of vaccines and biopharmaceuticals, demonstrating favorable safety, patient acceptance, and manufacturability at scale18.
Building on these advances, the present study describes the fabrication of dissolvable MN patches loaded with &#945;-lactalbumin nanomicelles encapsulating capsaicin. In this protocol, &#945;-lactalbumin is dissolved at 6 mg/mL and enzymatically hydrolyzed to generate amphiphilic peptides that self-assemble into capsaicin-loaded nanomicelles. The nanomicelles are incorporated into an HA/PVA matrix (5% w/v each) and cast into polydimethylsiloxane (PDMS) molds to form 10 &#215; 10 MN arrays with a needle height of 600 &#181;m, a configuration that is compatible with standard micro-molding processes and readily scalable to larger, human-sized patches. This integrated design is expected to improve capsaicin solubility and stability, provide pH-responsive release within adipose tissue, and enhance local anti-obesity efficacy in vivo by promoting adipose tissue browning, suppressing lipogenesis, and improving systemic metabolic parameters. By leveraging food-grade &#945;-lactalbumin and clinically advanced dissolving MN materials, this platform offers a translationally relevant, minimally invasive strategy that could be adapted to human-scale patches for self-administered, localized obesity therapy.

<table><tbody><tr><td>3T3-L1 preadipocytes</td><td>ATCC</td><td>CL-173</td><td>Cell line for adipogenesis studies</td></tr><tr><td>Bacillus licheniformis protease (BLP)</td><td>Sigma-Aldrich</td><td>P5380</td><td>Enzymatic hydrolysis of &amp;alpha;-lactalbumin</td></tr><tr><td>Capsaicin (&amp;ge;98%)</td><td>Sigma-Aldrich</td><td>M2028</td><td>Active compound to be encapsulated</td></tr><tr><td>Centrifuge (&amp;ge;4000 rpm)</td><td>Eppendorf</td><td>5810R</td><td>To fill molds</td></tr><tr><td>Confocal laser scanning microscope (CLSM)</td><td>Zeiss</td><td>LSM 900</td><td>To visualize micelle distribution and penetration</td></tr><tr><td>Cy3 fluorescent dye</td><td>GE Healthcare</td><td>PA23001</td><td>For labeling nanomicelles</td></tr><tr><td>Cy5 or Cy7 fluorescent dyes</td><td>Fanbo Biochemical, Beijing, China</td><td>N/A</td><td>For biodistribution imaging</td></tr><tr><td>Dulbecco&amp;rsquo;s Modified Eagle&amp;rsquo;s Medium (DMEM)</td><td>Gibco (Thermo Fisher Scientific)</td><td>11965-092</td><td>For cell culture</td></tr><tr><td>Ethanol (&amp;ge;99.7%)</td><td>Sinopharm Chemical Reagent</td><td>100092683</td><td>Solvent for capsaicin</td></tr><tr><td>Fetal bovine serum (FBS)</td><td>Gibco (Thermo Fisher Scientific)</td><td>16000-044</td><td>For cell culture</td></tr><tr><td>High-fat diet (60% kcal fat, D12492)</td><td>Research Diets, USA</td><td>D12492</td><td>To induce obesity in mice</td></tr><tr><td>Hyaluronic acid&lt;br/&gt; (HA, Mw 100&amp;ndash;300 kDa)</td><td>Aladdin Biochemical Technology Co., China</td><td>H108124</td><td>Polymer for microneedle fabrication</td></tr><tr><td>Isoflurane</td><td>RWD, China</td><td>R510-22-10</td><td>Anesthetic</td></tr><tr><td>Metabolic cage system</td><td>Panlab, USA</td><td>N/A</td><td>To assess activity, oxygen consumption, and RQ</td></tr><tr><td>Milli-Q Deionized water</td><td>Millipore</td><td>N/A</td><td>Solvent</td></tr><tr><td>MRI system</td><td>NiuMag, China</td><td>MesoQMR23-060H-I</td><td>To measure fat/lean body composition</td></tr><tr><td>PDMS microneedle molds (10 &amp;times; 10, 600 &amp;mu;m height)</td><td>Blueacre Technology or custom</td><td>N/A</td><td>Microneedle fabrication</td></tr><tr><td>Penicillin&amp;ndash;streptomycin</td><td>Gibco (Thermo Fisher Scientific)</td><td>15140-122</td><td>For cell culture</td></tr><tr><td>Phosphate-buffered saline&lt;br/&gt; &amp;nbsp;(PBS, pH 7.4)</td><td>Thermo Fisher Scientific</td><td>10010023</td><td>Buffer for in vitro and in vivo studies</td></tr><tr><td>Polyvinyl alcohol&lt;br/&gt; (PVA, Mw 30&amp;ndash;70 kDa)</td><td>Aladdin Biochemical Technology Co., China</td><td>P109389</td><td>Polymer for microneedle fabrication</td></tr><tr><td>Scanning electron microscope (SEM)</td><td>FEI Tecnai</td><td>G2 F30</td><td>To characterize microneedle morphology</td></tr><tr><td>Texture analyzer</td><td>BosinTech, Shanghai, China</td><td>TA.XTC-20</td><td>To test microneedle strength</td></tr><tr><td>Trypan blue solution (0.4%)</td><td>Thermo Fisher Scientific</td><td>15250061</td><td>To visualize microneedle insertion sites</td></tr><tr><td>UV&amp;ndash;Vis spectrophotometer</td><td>PerkinElmer</td><td>Lambda 35</td><td>For drug release assays</td></tr><tr><td>Vacuum oven/desiccator</td><td>Thermo Fisher Scientific</td><td>N/A</td><td>To dry microneedles</td></tr><tr><td>Western blotting apparatus</td><td>Bio-Rad</td><td>Mini-PROTEAN Tetra</td><td>Protein analysis</td></tr><tr><td>&amp;alpha;-Lactalbumin (&amp;ge;95%)</td><td>Sigma-Aldrich</td><td>L6010</td><td>Protein source for nanomicelle formation</td></tr></tbody></table>

fabrication of dissolvable microneedle patches loaded with &#945;-lactalbumin nanomicelles for transdermal capsaicin delivery and adipose tissue reduction

Fabrication of Dissolvable Microneedle Patches Loaded with &#945;-Lactalbumin Nanomicelles for Transdermal Capsaicin Delivery and Adipose Tissue Reduction

This protocol outlines the fabrication and application of dissolvable microneedle (MN) patches containing &#945;-lactalbumin nanomicelles for the targeted transdermal delivery of capsaicin to adipose tissue. The process begins with the partial enzymatic hydrolysis of &#945;-lactalbumin, resulting in amphiphilic peptides that self-assemble into nanomicelles encapsulating the hydrophobic compound capsaicin. The capsaicin-loaded nanomicelles are mixed with a hyaluronic acid (HA) and polyvinyl alcohol (PVA) matrix, cast into polydimethylsiloxane (PDMS) molds, and centrifuged to produce 10 &#215; 10 MN arrays. After vacuum drying, the MNs exhibit adequate mechanical strength for skin penetration and dissolve within approximately 30 min of application. Representative results include scanning electron microscopy, which confirms uniform morphology of MNs, confocal microscopy, which verifies skin penetration and drug release, and in vivo experiments in high-fat diet (HFD) mice showing reduced fat mass, enhanced metabolic activity, and induction of adipose browning. This protocol provides a reproducible and minimally invasive method for the transdermal delivery of hydrophobic bioactives, offering a promising therapeutic approach for the management of obesity. This protocol is optimized for reproducibility and is suitable for adaptation to other hydrophobic bioactives.

Morphology and characterization of nanomicelles 
Transmission electron microscopy (TEM) showed that α-lactalbumin nanomicelles were uniformly dispersed, spherical particles with a narrow size distribution (Figure 1). After capsaicin encapsulation, the mean particle diameter increased from ~22 nm to ~30 nm, indicating successful drug loading into the micellar core. Consistently, the zeta potential shifted slightly from −16.8 mV to −20.3 mV, further confirming efficient enc...

This protocol describes the fabrication of dissolvable microneedle patches incorporating &#945;-lactalbumin nanomicelles loaded with capsaicin. The method offers a reproducible, minimally invasive approach for targeted transdermal delivery of hydrophobic bioactives to adipose tissue, facilitating efficient local fat reduction and potentially expanding applications in obesity management.

This protocol outlines the fabrication and application of dissolvable microneedle (MN) patches containing &#945;-lactalbumin nanomicelles for the targeted ...

fabrication-dissolvable-microneedle-patches-loaded-with-lactalbumin

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JoVE Journal

Biochemistry

This article details the construction of a multiplexed microneedle-based sensor. The device is being developed for in situ sampling and electrochemical analysis of multiple analytes in a rapid and selective manner. We envision clinical medicine and biomedical research uses for these microneedle-based sensors.

Hollow Microneedle-based Sensor for Multiplexed Transdermal Electrochemical Sensing

Here, we present a protocol describing a mold-free fabrication process of the polymeric microneedles by photolithography.

Polymeric Microneedle Array Fabrication by Photolithography

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.

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

This article introduces a unique method for fabricating master molds with an air-vent hole to prevent air entrapment during viscous polymer casting, enabling the fabrication of gelatin microneedles with sharp tips. By reducing the casting volume of high-viscosity gelatin, thin-walled hollow pyramidal microneedles could also be fabricated.

Fabrication of a Master Mold for Microneedles with a Micron-sized Air-vent Hole

The present work aims to serve as a practical guide enabling researchers to prepare their own DMAP devices using the solvent-casting method, also known as micromolding, and to perform basic characterization.

Dissolving Microneedle Array Patches Manufactured By Solvent Casting Technique and Essential Characterization of Microneedle-Based Biomedical Devices

We describe procedures for the preparation and delivery of membrane protein microcrystals in lipidic cubic phase for serial crystallography at X-ray free-electron lasers and synchrotron sources. These protocols can also be applied for incorporation and delivery of soluble protein microcrystals, leading to substantially reduced sample consumption compared to liquid injection.

Preparation and Delivery of Protein Microcrystals in Lipidic Cubic Phase for Serial Femtosecond Crystallography

This protocol describes the method of determining basal and forskolin-stimulated lipolysis in inguinal fat pads obtained from normal chow diet (NCD) or high fat diet (HFD) ± capsaicin fed wild type mice. As an index for lipolysis, glycerol release was measured from inguinal adipose fat pads.

Measurement of Basal and Forskolin-stimulated Lipolysis in Inguinal Adipose Fat Pads

The protein composition of the human mitral valve is still partially unknown, because its analysis is complicated by low cellularity and therefore by low protein biosynthesis. This work provides a protocol to efficiently extract protein for the analysis of the mitral valve proteome.

Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve

The purpose of this paper is to present a step-by-step procedure to collect different white adipose tissues from mice, process the fat samples and extract RNA.

Mouse Adipose Tissue Collection and Processing for RNA Analysis

Here we present a protocol for controlled production of protein microcrystals. The process uses an automated device allowing controlled manipulation of several crystallization parameters. The protein crystallization is carried-out by controlled and automated addition of crystallization solutions while monitoring and investigating the radius distribution of particles in the crystallization droplet.

Growing Protein Crystals with Distinct Dimensions Using Automated Crystallization Coupled with In Situ Dynamic Light Scattering

Learn to fabricate dissolvable microneedle patches loaded with α-lactalbumin nanomicelles for transdermal capsaicin delivery. This method enables targeted adipose tissue reduction in obesity research.

Fabrication of Dissolvable Microneedle Patches Loaded with α-Lactalbumin Nanomicelles for Transdermal Capsaicin Delivery and Adipose Tissue Reduction (Video) | JoVE Journal

Fabrication of Dissolvable Microneedle Patches Loaded with α-Lactalbumin Nanomicelles for Transdermal Capsaicin Delivery and Adipose Tissue Reduction

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