Dissolving Microneedle Patch Research Articles

Targeting TGFβ receptor-mediated snail and twist: WSG, a polysaccharide from Ganoderma lucidum, and it-based dissolvable microneedle patch suppress melanoma cells

Cutaneous melanoma is a lethal skin cancer variant with pronounced aggressiveness and metastatic potential. However, few targeted medications inhibit the progression of melanoma. Ganoderma lucidum, which is a type of mushroom, is widely used as a non-toxic alternative adjunct therapy for cancer patients. This study determines the effect of WSG, which is a water-soluble glucan that is derived from G. lucidum, on melanoma cells. The results show that WSG inhibits cell viability and the mobility of melanoma cells. WSG induces changes in the expression of epithelial-to-mesenchymal transition (EMT)-related markers. WSG also downregulates EMT-related transcription factors, Snail and Twist. Signal transduction assays show that WSG reduces the protein levels in transforming growth factor β receptors (TGFβRs) and consequently inhibits the phosphorylation of intracellular signaling molecules, such as FAK, ERK1/2 and Smad2. An In vivo study shows that WSG suppresses melanoma growth in B16F10-bearing mice. To enhance transdermal drug delivery and prevent oxidation, two highly biocompatible compounds, polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), are used to synthesize a dissolvable microneedle patch that is loaded with WSG (MN-WSG). A functional assay shows that MN-WSG has an effect that is comparable to that of WSG alone. These results show that WSG has significant potential as a therapeutic agent for melanoma treatment. MN-WSG may allow groundbreaking therapeutic approaches and offers a novel method for delivering this potent compound effectively.

Nanosuspension-Loaded Dissolving Microneedle Patches for Enhanced Transdermal Delivery of a Highly Lipophilic Cannabidiol.

Transdermal Drug Delivery System (TDDS) offers a promising alternative for delivering poorly soluble drugs, challenged by the stratum corneum's barrier effect, which restricts the pool of drug candidates suitable for TDDS. This study aims to establish a delivery platform specifically for highly lipophilic drugs requiring high doses (log P > 5, dose > 10 mg/kg/d), to improve their intradermal delivery and enhance solubility. Cannabidiol (CBD, log P = 5.91) served as the model drug. A CBD nanosuspension (CBD-NS) was prepared using a bottom-up method. The particle size, polydispersity index (PDI), zeta potential, and concentration of the CBD-NS were characterized. Subsequently, CBD-NS was incorporated into dissolving microneedles (DMNs) through a one-step manufacturing process. The intradermal dissolution abilities, physicochemical properties, mechanical strength, insertion depth, and release behavior of the DMNs were evaluated. Sprague-Dawley (SD) rats were utilized to assess the efficacy of the DMN patch in treating knee synovitis and to analyze its skin permeation kinetics and pharmacokinetic performance. The CBD-NS, stabilized with Tween 80, exhibited a particle size of 166.83 ± 3.33 nm, a PDI of 0.21 ± 0.07, and a concentration of 46.11 ± 0.52 mg/mL. The DMN loaded with CBD-NS demonstrated favorable intradermal dissolution and mechanical properties. It effectively increased the delivery of CBD into the skin, extended the action's duration in vivo, and enhanced bioavailability. CBD-NS DMN exhibited superior therapeutic efficacy and safety in a rat model of knee synovitis, significantly inhibiting TNF-α and IL-1β compared with the methotrexate subcutaneous injection method. NS technology effectively enhances the solubility of the poorly soluble drug CBD, while DMN facilitates penetration, extends the duration of action in vivo, and improves bioavailability. Furthermore, CBD has shown promising therapeutic outcomes in treating knee synovitis. This innovative drug delivery system is expected to offer a more efficient solution for the administration of highly lipophilic drugs akin to CBD, thereby facilitating high-dose administration.

In situ polymeric nanomicelle-generating dissolving microneedle patch for enhanced transdermal methotrexate delivery in rheumatoid arthritis treatment

Rheumatoid arthritis (RA) presents a chronic autoimmune pathology. Methotrexate (MTX), a primary therapeutic agent for RA, often administered orally or via injection, has shown dose-dependent systemic toxicity upon prolonged use. Consequently, a pressing need exists for a secure and facile MTX delivery system in RA management. In the current study, the methoxy poly (ethylene glycol)-poly (lactide) polymer (mPEG-PLA) and hyaluronic acid (HA) were used as materials for both nanomicelles and dissolving microneedles (MNs) to facilitate the effective transdermal delivery of MTX in RA therapy. HA, a specific ligand for the CD44 receptor, could deposit on the outer surface of nanomicelles by interacting with mPEG-PLA, which serve as a targeting ligand for macrophages activated at inflamed joints. Upon MTX-loaded polymeric nanomicelles MNs (MTX@PMs MNs) application to the skin, MNs could effectively puncture the stratum corneum and in situ generate nanomicelles with the dissolution of MNs. In vivo therapeutic efficiency evaluations suggested that the MTX@PMs MNs demonstrated enhanced efficacy in mitigating the progression of RA without inducing treatment-related toxicity. Our findings suggest that the utilization of in situ polymeric nanomicelle-generating dissolving microneedle patches holds promise as a potential strategy for the clinical treatment of RA.

Innovative freeze-drying technique in the fabrication of dissolving microneedle patch: Enhancing transdermal drug delivery efficiency.

Microneedle patch (MNP) has become a hot research topic in the field of transdermal drug delivery due to its ability to overcome the stratum corneum barrier. Among the various types of microneedles, dissolving microneedles represent one of the most promising transdermal delivery methods. However, the most used method for preparing dissolving microneedles, namely microfabrication, suffers from issues such as long drying time, susceptibility to humidity, and large batch-to-batch variability, which limit the development of dissolving microneedles. In this study, we report for the first time a method for preparing dissolving microneedles using freeze-drying technology. We screened substrates suitable for freeze-dried microneedle patch (FD-MNP) and used coating technology to enhance the mechanical strength of FD-MNP, allowing them to meet the requirements for skin penetration. We successfully prepared FD-MNP using hyaluronic acid as the substrate and insulin as the model drug. Scanning electron microscopy revealed that the microneedles had a porous structure. After coating, the mechanical strength of the microneedles was 0.61N/Needle, and skin penetration rate was 97%, with a penetration depth of 215μm. The tips of the FD-MNP dissolved completely within approximately 60s after skin penetration, which is much faster than conventional MNP (180s). In vitro transdermal experiments showed that the FD-MNP shortened the lag time for transdermal delivery of rhodamine 123 and insulin compared to conventional MNP, indicating a faster transdermal delivery rate. Pharmacological experiments showed that the FD-MNP lowered mouse blood glucose levels more effectively than conventional MNP, with a relative pharmacological availability of 96.59 ± 2.84%, higher than that of conventional MNP (84.34 ± 3.87%), P = 0.0095. After storage under 40℃ for two months, the insulin content within the FD-MNP remained high at 95.27 ± 4.46%, which was much higher than that of conventional MNP (58.73 ± 3.71%), P < 0.0001. In conclusion, freeze-drying technology is a highly valuable method for preparing dissolving microneedles with potential applications in transdermal drug delivery.

Rizatriptan benzoate-loaded dissolving microneedle patch for management of acute migraine therapy.

In this study, dissolving microneedles (MNs) using polyvinyl alcohol (PVA) and poly (1-vinylpyrrolidone-co-vinyl acetate) (P(VP-co-VA)) as matrix materials were developed for transdermal delivery of rizatriptan benzoate (RB) for acute migraine treatment. In-vitro permeation studies were conducted to assess the feasibility of the as-fabricated dissolving MNs to release RB. Drug skin penetration were tested by Franz diffusion cells, showing an increase of the transdermal flux compared to passive diffusion due to the as-fabricated dissolving MNs having a sufficient mechanical strength to penetrate the skin and form microchannels. The pharmacological study in vivo showed that RB-loaded dissolving MNs significantly alleviated migraine-related response by up-regulating the level of 5-hydroxytryptamine (5-HT) and down-regulating the levels of calcitonin gene-related peptide (CGRP) and substance P (SP). In conclusion, the RB-loaded dissolving MNs have advantages of safety, convenience, and high efficacy over conventional administrations, laying a foundation for the transdermal drug delivery system treatment for acute migraine.

ATP-adenosine axis regulation combined with microneedle assisted photoimmunotherapy to boost the immunotherapy efficiency

Immunogenic cell death (ICD) is associated with the release of damage-associated molecular patterns, including ATP, to promote an effective immune cycle against tumors. However, tumors have evolved an effective strategy for degrading extracellular immunostimulatory ATP via the ATP-adenosine axis, allowing the sequential action of the ectonucleotidases CD39 to degrade accumulated immunostimulatory ATP into pleiotropic immunosuppressive adenosine. Here, an ingenious dissolving microneedle patch (DMNs) is designed for the intralesional delivery of CD39 inhibitor (sodium polyoxotungstate, POM-1) and ICD inducer (IR780) co-encapsulated solid lipid nanoparticles (P/I SLNs) for antitumor therapy. Upon insertion into the tumor site, IR780 induces ICD modalities with the release of damage-associated molecular patterns from endogenous tissues, which activates the antitumor immune cycle. Simultaneously, POM-1 promotes the liberation of immunostimulatory ATP and lowers the level of immunosuppressive extracellular adenosine, which supported immune control of tumors via recruiting CD39-expressing immune cells. In vivo antitumor studies prove that this platform can effectively eliminate mice melanoma (tumor growth inhibitory rate of 96.5%) and colorectal adenocarcinoma (tumor growth inhibitory rate of 93.5%). Our results shed light on the immunological aspects of combinatorial phototherapy and ATP-adenosine regulation, which will broaden the scope of synergistic antitumor immunotherapy.

It Takes Two to Tangle: Microneedle Patches Co-delivering Monoclonal Antibodies and Engineered Antimicrobial Peptides Effectively Eradicate Wound Biofilms.

Wound biofilms pose a great clinical challenge. Herein, this work reports a dissolvable microneedle patch for dual delivery of monoclonal antibodies anti-PBP2a and engineers antimicrobial peptides W379. In vitro antibacterial efficacy testing with microneedle patches containing a combination of 250 ngmL-1 W379 and 250 ngmL-1 anti-BPB2a decreases the bacterial count from ≈3.31 × 107 CFUmL-1 to 1.28 × 102 CFUmL-1 within 2 h without eliciting evident cytotoxicity. Ex vivo testing indicates W379 and anti-PBP2a co-loaded microneedle patch displayed a remarkable reduction of bacterial load by ≈7.18 log CFU after administered only once within 48 h. The bacterial count is significantly diminished compared to the treatment by either W379 or anti-PBP2a-loaded alone microneedle patches. When administered twice within 48 h, no bacteria are identified. Further in vivo study also reveals that after two treatments of W379 and anti-PBP2a co-loaded PVP microneedle patches within 48 h, the bacterial colonies are undetectable in a type II diabetic mouse wound biofilm model. Taken together, W379 and anti-PBP2a co-loaded PVP microneedle patches hold great promise in treating wound biofilms.

Influence of Low‐Frequency Vibration and Skin Strain on Insertion Mechanics and Drug Diffusion of PVA/PVP Dissolving Microneedles

AbstractMicroneedles (MNs) offer a promising solution for increasing the effectiveness of transdermal drug delivery and diagnostics. However, challenges such as large‐scale manufacturing, partial MN penetration, and uncontrolled drug delivery limit the effectiveness of the technology. To overcome these challenges, current research examines the effects of skin strain and vibration on MN insertion and drug delivery. A novel multifeatured impact applicator are developed for improving skin insertion that features a combination of skin stretching, eccentric rotating mass (ERM), and linear resonant actuator (LRA) micro‐vibration capabilities. In addition, a scalable replication method for dissolving microneedle patches (DMNPs) are developed using two‐photon polymerization (TPP) and soft embossing processes. The DMNPs are used to evaluate the diffusion and concentration of a model drug, fluorescein sodium salt (FSS), when applied using ERM and LRA micro‐vibration at different frequencies. Additionally, a new computer simulation method is presented to model the MN insertion into the multilayered hyperelastic skin model, incorporating skin strain and vibrational effects. The results indicate that applying skin strain and vibration decreases the force required for MN insertion and enhances the dissolution and diffusion depth of the drug in the skin, which can enhance the drug permeability and effectiveness of MN devices.

Clinical Safety and Efficacy Evaluation of a Dissolving Microneedle Patch Having Dual Anti-Wrinkle Effects With Safe and Long-Term Activities.

Anti-aging products are widely used, but the desire for safe and more efficient anti-aging products continues to increase. Dissolving microneedle patches (MNPs) have provided a more efficient transdermal drug delivery solution. MNP is a promising candidate for developing better anti-aging products. To develop a more efficient anti-aging MNP product, we fabricated a dual anti-wrinkle microneedle patch (named DA-MNP) using droplet extension (DEN®) technology and evaluated its skin puncture ability, safety, and efficacy through clinical studies. A DA-MNP comprising hyaluronic acid (HA) polymer backbone, acetyl octapeptide-3, and L-ascorbic acid 2-glucoside and sodium cyclic lysophosphatidic acid was fabricated using DEN® technology. Placebo MNPs comprising only HA were also fabricated. Twenty-four healthy subjects were enrolled in this comparative clinical study. The DA-MNP or placebo MNP was separately applied to the left and right eyes of subjects for overnight. Assessments, including wrinkle improvement, trans-epidermal water loss (TEWL), eye lifting and adverse effects were evaluated at each scheduled visit day for 28 days. The DA-MNP showed mechanical strength enough for puncturing the stratum corneum. Compared to placebo MNP group, the DA-MNP treated group showed an effective eye wrinkles improvement and better anti-aging of skin, with reduced TEWL, enhanced skin elasticity and lifting, and no adverse effects. The present study demonstrated that the fabricated DA-MNP exhibited fast acting on deep wrinkles and enhanced anti-aging efficacy, with no skin safety concern. Thus, this DA-MNP may serve as a new transdermal delivery solution for skin wrinkling and aging.

Transdermal codelivery system of resveratrol nanocrystals and fluorouracil@ HP-β-CD by dissolving microneedles for cutaneous melanoma treatment

Cutaneous melanoma is a serious malignant tumor. In recent years, the morbidity and mortality rate of this disease have been continuously and rapidly increasing. Codelivery of natural product resveratrol (RES) and chemical synthetic drug fluorouracil (Fu) is beneficial to achieve reduced toxicity and increased efficacy effects for melanoma therapeutic. However, the poor solubility and bioavailability of the two drugs resulted in deficient effective and systemic toxicity due to high dose administration. Furthermore, these shortcomings also lead to drug resistance and unsatisfactory patient compliance. In this study, a codelivery dissolvable microneedle (DMN) patch was designed by carrying RES nanocrystals and Fu@hydroxypropyl-beta-cyclodextrin (HP-β-CD) for a synergistic effect. The RES nanocrystals exhibited satisfied solubility and dissolution properties in vitro, and the Fu inclusion compound with HP-β-CD resulted in satisfactory drug loading. Laser confocal fluorescence microscopy demonstrated uniform distribution of both drugs in the DMN. Mechanical tests and in vitro and in vivo puncture tests of the DMN exhibited great mechanical and insertion properties. The DMN in the Franz diffusion cell test released 84.13 ± 5.19 % of the RES and 90.65 ± 18.23 % of the Fu at 12 h. Additionally, for in vivo release, the DMN released 81.24 ± 5.23 % of the RES and 72.48 ± 7.82 % of the Fu. All excipients of the DMN presented high biosafety. In conclusion, codelivery of RES nanocrystals and Fu@HP-β-CD by the DMN presented an excellent pharmaceutical and biological properties and satisfied potential clinical application prospects for cutaneous melanoma treatment.

Fast dissolving microneedle patch for pronounced systemic delivery of an antihyperlipidemic drug

Fast dissolving microneedles (F-dMN) are quite a novel approach delivering specific drug molecules directly into the bloodstream, bypassing the first-pass effect. The present study reported an F-dMN patch to enhance systemic delivery of simvastatin in a patient-friendly manner. The F-dMN patch was developed using polyvinyl pyrrolidone and polyvinyl alcohol and characterized using light microscopy, SEM, XRD, FTIR, mechanical strength, drug content (%), an ex-vivo penetration study, an ex-vivo drug release study, a skin irritation test, and a pharmacokinetics study. The optimized F-dMN patch exhibited excellent elongation of 35.17%, good tensile strength of 9.68 MPa, an appropriate moisture content of 5.65%, and good penetrability up to 560 µm. Moreover, it showed 93.4% of the drug content within the needles and 81.75% in-vitro release. Histopathological findings and a skin irritation study proved that the F-dMN patch was biocompatible and did not cause any sort of irritation on animal skin. Pharmacokinetic parameters of F-dMN patches were improved (Cmax 6.974 µg/ml, tmax 1 hr and AUC 19. 518 µg.h/ml) as compared to tablet Simva 20 mg solution (Cmax 2.485 µg/ml, tmax 1.4 hr and AUC 11.199 µg.h/ml), thus confirming bioavailability enhancement. Moreover, stability studies confirmed the stability of the developed F-dMN patch, as investigated by axial needle fracture force and drug content.

Application of microneedles combined with dendritic cell-targeted nanovaccine delivery system in percutaneous immunotherapy for triple-negative breast cancer

This work aims at developing a strategy to activate the antigen-presenting cells to enhance the effect of immunotherapy in triple-negative breast cancer (TNBC) through the dissolving microneedle patch (DMNP). In present study, mannosylated chitosan (MCS) nanoparticles (NPs) were designed to target dendritic cells (DCs), and the immunotherapy effect was enhanced by the adjuvant Bacillus Calmette–Guerin polysaccharide (BCG-PSN), achieving the purpose of transdermal immunotherapy for TNBC. Vaccination studies with mice demonstrated that MCS NPs effectively induce DCs maturation in the tumor-draining lymph nodes to stimulate strong immune responses in TNBC. Overall, chitosan-based DMNPs with complex adjuvant constituted a new potent transdermal vaccine delivery platform capable of exploiting more DCs in the skin for effective immunization.

A Rapidly Dissolvable Microneedle Patch with Tip-Accumulated Antigens for Efficient Transdermal Vaccination.

Dissolvable microneedles (DMNs) are an attractive alternative for vaccine delivery due to their user-friendly, skin-targeted, and minimally invasive features. However, vaccine waste and inaccurate dosage remain significant issues faced by DMNs, as the skin's elasticity makes it difficult to insert MNs completely. Here, we introduce a simple and reliable fabrication method based on two-casting micromolding with centrifugal drying to create a rapidly DMN patch made of hyaluronic acid. Ovalbumin (OVA), as the model antigens, is concentrated in the tip parts of the DMNs (60% of the needle height) to prevent antigen waste caused by skin elasticity. The time and temperature of the initial centrifugal drying significantly affect antigen distribution within the needle tips, with lower temperature facilitating antigen accumulation. The resulting DMN patch is able to penetrate the skin with enough mechanical strength and quickly release antigens into the skin tissue within 3min. The in vivo study demonstrates that immunization of OVA with DMNs outperforms conventional vaccination routes, including subcutaneous and intramuscular injections, in eliciting both humoral and cellular immunity. This biocompatible DMN patch offers a promising and effective strategy for efficient and safe vaccination. This article is protected by copyright. All rights reserved.

Clinical Development and Evaluation of a Multi-Component Dissolving Microneedle Patch for Skin Pigmentation Disorders.

Excessive melanin deposition in the skin leads to various skin pigmentation diseases, such as chloasma and age spots. The deposition is induced by several factors, including tyrosinase activities and ultraviolet-induced oxidative stress. Herein, we propose a multi-component, multi-pathway drug combination, with glabridin, 3-O-ethyl-L-ascorbic acid, and tranexamic acid employed as, respectively, a tyrosinase inhibitor, an antioxidant, and a melanin transmission inhibitor. Considering the poor skin permeability associated with topical application, dissolving microneedles (MNs) prepared with hyaluronic acid/poly(vinyl alcohol)/poly(vinylpyrrolidone) were developed to load the drug combination. The drug-loaded microneedles (DMNs) presented outstanding skin insertion, dissolution, and drug delivery properties. In vitro experiments confirmed that DMNs loaded with active ingredients had significant antioxidant and inhibitory effects on tyrosinase activity. Furthermore, the production of melanin both in melanoma cells (B16-F10) and in zebrafish was directly reduced after using DMNs. Clinical studies demonstrated the DMNs' safety and showed that they have the ability to effectively reduce chloasma and age spots. This study indicated that a complex DMN based on a multifunctional combination is a valuable depigmentation product worthy of clinical application.

PLGA Nanoparticle-Based Dissolving Microneedle Vaccine of Clostridium perfringens ε Toxin

Epsilon toxin (ETX) is an exotoxin produced by type B and D Clostridium perfringens that causes enterotoxemia or necrotic enteritis in animals such as goats, sheep, and cattle. Vaccination is a key method in preventing such diseases. In this study, we developed a new type of dissolving microneedle patch (dMN) with a nanoparticle adjuvant for enhanced immune response to deliver the rETXY196E-C protein vaccine. We chose FDA-approved poly(lactic-co-glycolic acid) (PLGA) to prepare nanospheres as the vaccine adjuvant and introduced dimethyldioctadecylammonium bromide (DDAB) to make the surface of PLGA nanoparticles (PLGA NPs) positively charged for antigen adsorption. PLGA NPs with a diameter of 100~200 nm, a surface ZETA potential of approximately +40 mV, and good safety were successfully prepared and could effectively adsorb rETXY196E-C protein. Using non-toxic and antibacterial fish gelatin as the microneedle (MN) matrix, we prepared a PLGA-DDAB dMN vaccine with good mechanical properties that successfully penetrated the skin. After immunization of subcutaneous (SC) and dMN, antibody titers of the PLGA and Al adjuvant groups were similar in both two immune ways. However, in vivo neutralization experiments showed that the dMN vaccines had a better protective effect. When challenged with 100 × LD50 GST-ETX, the survival rate of the MN group was 100%, while that of the SC Al group was 80%. However, a 100% protective effect was achieved in both immunization methods using PLGA NPs. In vitro neutralization experiments showed that the serum antibodies from the dMN and SC PLGA NPs groups both protect naive mice from 10 × LD50 GST-ETX attack after being diluted 20 times and could also protect MDCK cells from 20 × CT50 GST-ETX attack. In conclusion, the PLGA-DDAB dMN vaccine we prepared has good mechanical properties, immunogenicity, and protection, and can effectively prevent ETX poisoning. This provides a better way of delivering protein vaccines.

Dissolvable hybrid microneedle patch for efficient delivery of curcumin to reduce intraocular inflammation

Intraocular inflammation seriously impairs vision, and the effectiveness of intraocular drug delivery is hampered by various physiological barriers, such as the corneal barrier. In this paper, we present a simple approach to fabricating a dissolvable hybrid microneedles (MNs) patch for the efficient delivery of curcumin to treat intraocular inflammatory disorders. Water-insoluble curcumin was first encapsulated into polymeric micelles with high anti-inflammatory capacities, and then were combined with hyaluronic acid (HA) to create a dissolvable hybrid MNs patch using a simple micromolding method. Curcumin was amorphously dispersed within the MNs patch as indicated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD) analyses. According to an in vitro drug release study, the proposed MNs patch provided sustainable drug release over 8 h. Following its in vivo topical application, the MNs patch demonstrated an extended pre-corneal retention time over 3.5 h and exhibited great ocular biocompatibility. Additionally, such MNs patch could reversibly penetrate the corneal epithelium, generating an array of microchannels on the corneal surface, thereby increasing ocular bioavailability. Of greater significance, the use of MNs patch demonstrated the improved therapeutic effectiveness in treating endotoxin-induced uveitis (EIU) in a rabbit model compared to curcumin eye drops via a significant reduction in the infiltration of inflammatory cells such as CD45+ leukocytes and CD68+ macrophages. Overall, the topical application of the MNs patch as an efficient ocular drug delivery system could potentially serve as a promising approach for treating different types of intraocular disorders.

Sublingual Dissolving Microneedle (SLDMN)-Based Vaccine for Inducing Mucosal Immunity against SARS-CoV-2.

The coronavirus pandemic has accelerated the development of next-generation vaccination technology to combat future pandemic outbreaks. Mucosal vaccination effectively protects the mucosal surfaces, the primary sites of viral entry, by inducing the secretion of immunoglobulin A (IgA) and humoral IgG. Here, a dissolving microneedle (DMN) is adopted as a mucosal vaccine delivery platform to directly penetrate the sublingual site, which is rich in antigen-presenting cells (APCs) and lymphoid tissues. The sublingual dissolving microneedle (SLDMN) vaccination platform comprised a micropillar-based compartment and a 3D-printed SLDMN applicator as a substitute for the DMN patch. The penetration efficacy of SLDMNs is assessed using in vitro optical coherence tomography (OCT) and in vivo histological analysis. The efficacy of SLDMN is also evaluated in a vaccine form using the recombinant spike (S1) protein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Furthermore, SLDMN is used to challenge transgenic mice expressing human angiotensin-converting enzyme 2 (hACE2) receptors. Its effects are evaluated on antibody production, survival rate, and inflammation attenuation after infection compared to the intramuscular (IM) injections. Overall, SLDMN effectively induced mucosal immunity via IgA secretion, attenuated lung inflammation, and lowered the levels of cytokines and chemokines, which may prevent the "cytokine storm" after SARS-CoV-2 infection.

Protection against tuberculosis achieved by dissolving microneedle patches loaded with live Mycobacterium paragordonae in a BCG prime-boost strategy.

Skin vaccination using dissolving microneedle patch (MNP) technology for transdermal delivery is a promising vaccine delivery strategy to overcome the limitations of the existing vaccine administration strategies using syringes. To improve the traditional microneedle mold fabrication technique, we introduced droplet extension (DEN) to reduce drug loss. Tuberculosis remains a major public health problem worldwide, and BCG revaccination had failed to increase the protective efficacy against tuberculosis. We developed an MNP with live Mycobacterium paragordonae (Mpg) (Mpg-MNP) as a candidate of tuberculosis booster vaccine in a heterologous prime-boost strategy to increase the BCG vaccine efficacy. The MNPs were fabricated by the DEN method on a polyvinyl alcohol mask film and hydrocolloid-adhesive sheet with microneedles composed of a mixture of mycobacteria and hyaluronic acid. We assessed the transdermal delivery efficiency by comparing the activation of the dermal immune system with that of subcutaneous injection. A BCG prime Mpg-MNP boost regimen was administered to a mouse model to evaluate the protective efficacy against M. tuberculosis. We demonstrated the successful transdermal delivery achieved by Mpg-MNP compared with that observed with BCG-MNP or subcutaneous vaccination via an increased abundance of MHCII-expressing Langerin+ cells within the dermis that could migrate into draining lymph nodes to induce T-cell activation. In a BCG prime-boost regimen, Mpg-MNP was more protective than BCG-only immunization or BCG-MNP boost, resulting in a lower bacterial burden in the lungs of mice infected with virulent M. tuberculosis. Mpg-MNP-boosted mice showed higher serum levels of IgG than BCG-MNP-boosted mice. Furthermore, Ag85B-specific T-cells were activated after BCG priming and Mpg-MNP boost, indicating increased production of Th1-related cytokines in response to M. tuberculosis challenge, which is correlated with enhanced protective efficacy. The MNP fabricated by the DEN method maintained the viability of Mpg and achieved effective release in the dermis. Our data demonstrate a potential application of Mpg-MNP as a booster vaccine to enhance the efficacy of BCG vaccination against M. tuberculosis. This study produced the first MNP loaded with nontuberculous mycobacteria (NTM) to be used as a heterologous booster vaccine with verified protective efficacy against M. tuberculosis.

Hepatitis B vaccine delivered by microneedle patch: Immunogenicity in mice and rhesus macaques.

Vaccination against hepatitis B using a dissolving microneedle patch (dMNP) could increase access to the birth dose by reducing expertise needed for vaccine administration, refrigerated storage, and safe disposal of biohazardous sharps waste. In this study, we developed a dMNP to administer hepatitis B surface antigen (HBsAg) adjuvant-free monovalent vaccine (AFV) at doses of 5µg, 10µg, and 20µg, and compared its immunogenicity to vaccination with 10µg of standard monovalent HBsAg delivered by intramuscular (IM) injection either in an AFV format or as aluminum-adjuvanted vaccine (AAV). Vaccination was performed on a three dose schedule of 0, 3, and 9weeks in mice and 0, 4, and 24weeks in rhesus macaques. Vaccination by dMNP induced protective levels of anti-HBs antibody responses (≥10 mIU/ml) in mice and rhesus macaques at all three HBsAg doses studied. HBsAg delivered by dMNP induced higher anti-HBsAg antibody (anti-HBs) responses than the 10µg IM AFV, but lower responses than 10µg IM AAV, in mice and rhesus macaques. HBsAg-specific CD4+ and CD8+ T cell responses were detected in all vaccine groups. Furthermore, we analyzed differential gene expression profiles related to each vaccine delivery group and found that tissue stress, T cell receptor signaling, and NFκB signaling pathways were activated in all groups. These results suggest that HBsAg delivered by dMNP, IM AFV, and IM AAV have similar signaling pathways to induce innate and adaptive immune responses. We further demonstrated that dMNP was stable at room temperature (20°C-25°C) for 6months, maintaining 67±6 % HBsAg potency. This study provides evidence that delivery of 10µg (birth dose) AFV by dMNP induced protective levels of antibody responses in mice and rhesus macaques. The dMNPs developed in this study could be used to improve hepatitis B birth dose vaccination coverage levels in resource limited regions to achieve and maintain hepatitis B elimination.

FABRICATION AND DEVELOPMENT OF DISSOLVING MICRONEEDLE PATCH OF BUTORPHANOL TARTRATE

Objective: Butorphanol is a commonly used medication for the management of postoperative pain and suffers low bioavailability and high first-pass metabolism. The objective of the current studies was to develop a butorphanol tartrate-loaded dissolving microneedle patch to overcome the limitation of first-pass metabolism without causing any discomfort to the patient. Methods: Butorphanol tartrate-loaded microneedle patch was prepared using Lapox resin micro-molds. The microneedle patch was optimized using the box-Behnken design and the quantity of PVA, HPMC K4M, and HPMC K15M was optimized and evaluated for fractured axial force, microscopic evaluation, in vitro drug permeation studies, and ex-vivo permeation experiments. Results: The developed microneedle patch meets all the evaluation parameters within the desired range. The height and tip diameter of the microneedles were found to be 700 µm to 800 µm and 60 µm to 61 µm. An axial fractured force of the optimized microneedle patch was found to be 189.67 N, suitable for penetrating the stratum corneum. The in vitro cumulative % drug permeated showed the permeation of the drug for 8 h with a total of 89.12 %, which shows the permeation of the drug occurred in a controlled manner. Conclusion: Butorphanol tartrate-loaded microneedle patch was successfully developed and the results concluded that the microneedles were hard enough to pass the stratum corneum and release the drug into the systemic circulation without reaching the pain receptors; further, the release study suggested that the drug was released for a prolonged period eliminating the problem of first-pass effect and frequent administration.