Dissolving microneedles-based programmed delivery system for enhanced chemo-immunotherapy of melanoma

Dissolving microneedles for nucleic acid delivery: A systematic search, review, and data synthesis

Dissolving microneedles deliver many classes of nucleic acids, overcoming susceptibility to enzymatic cleavage and poor intracellular delivery. Understanding the impact of microneedle formulation on nucleic acid therapeutic efficacy is critical for clinical translation. Here, we performed a systematic search to identify preclinical dissolving microneedle studies that deliver nucleic acid therapeutics including aptamers, DNA enzymes, mRNA, miRNA, plasmid DNA, recombinant viral vectors, and siRNA. This review quantitatively synthesizes preclinical data to identify correlations between microneedle form and function. Factors such as polymer molecular weight and incorporation of a nucleic acid carrier strongly influence mechanical and biological properties, while other design parameters allow for more flexibility. Altogether, 83 % of studies show equivalent or superior efficacy to existing nucleic acid administration routes including topical, subcutaneous, and intramuscular administration. Data especially supports the use of dissolving microneedles for viral and cancer vaccine applications, with a growing body of work exploring their utility for gene silencing. Nonetheless, several knowledge gaps remain. Emerging nucleic acid carrier chemistries that retain efficacy with improved toxicity profiles will define the next generation of formulations. Plasmid DNA and viral vectors show excellent long-term stability in dissolving microneedles, but further characterization is needed for long RNA transcripts. Finally, future work could explore the potential for non-dermal administration routes, as well as co-delivery of nucleic acids with small molecules to leverage synergistic effects. STATEMENT OF SIGNIFICANCE: This review comprehensively, critically, and quantitatively synthesizes preclinical dissolving microneedles for nucleic acid delivery. This approach identifies empirically supported correlations between microneedle form and function, highlighting evidence-based best practices and remaining challenges. The form-function relationships identified in this review will be valuable to those within the immediate microneedle field, as well as more broadly to audiences interested in nucleic acid therapeutics, drug delivery systems, microfabrication, and delivery strategies for low resource settings.

Microneedle-based nanodrugs for tumor immunotherapy

Microneedles have emerged as a promising and effective method for delivering therapeutic drugs and immunobiologics to treat various diseases. It is widely recognized that immune therapy has limited efficacy in solid tumors due to physical barriers and the immunosuppressive tumor microenvironment. Microneedle-based nanodrugs (NDMNs) offer a novel approach to overcome these limitations. These tiny needles are designed to load a variety of inorganic and organic nanoparticles, antigen vaccines, gene drugs, oncolytic viruses, and more. Utilizing microneedle arrays, NDMNs can effectively penetrate the skin barrier, delivering drugs precisely to the tumor site or immunoactive regions within the skin. Additionally, by designing and optimizing the microneedle structure, shape, and functionality, NDMNs enable precise drug release and efficient penetration, thereby enhancing the efficacy of tumor immunotherapy. In this review, we comprehensively discuss the pivotal role of NDMNs in cancer immunotherapy, summarizing innovative microneedle design strategies, mechanisms of immune activation, and delivery strategies of various nanodrugs. Furthermore, we explore the current clinical realities, limitations, and future prospects of NDMNs in tumor immunotherapy.

Dissolving microneedles for melanoma: Most recent updates, challenges, and future perspectives

Skin cancer is one among the common types of cancers, affecting millions of individual globally. The conventional anticancer therapy such as chemotherapy results in worst systemic and local side effects as well as inhibit the growth of healthy cells around the tumor cells. Dissolving microneedles (DMNs) is a groundbreaking technology with less invasive and more targeted features. Physically, these tiny dissolving needles deliver the anticancer payloads drug to the tumor site after its direct application on the skin surface. Specifically, the DMNs release the anticancer drug cargoes into the cancerous cell sparing the healthy cells around the tumor, thus has provided a significant contribution in the landscape of traditional skin cancer therapy. This targeted therapeutic approach of dissolving microneedles shows a significant therapeutic outcome in decreasing the growth of cancer cells in pre-clinical studies. Dissolving microneedles (DMNs) have demonstrated effectiveness in the targeted delivery of drugs, genes, and vaccines specifically at the site of skin tumors. This method mimics the localized release of adjuvants and immunomodulators, leading to significant humoral and cellular immune responses that are beneficial for skin cancer therapy. In this review, the current trends and potential roles of dissolving microneedles in delivering therapeutic agents focused on treating skin melanoma have been highlighted, drawing insights from recent literature. This emphasizes the promising applications of DMNs in enhancing treatment outcomes for skin cancer patients. Lastly, future perspectives were identified for improving the therapeutic potential and translation of DMNs into clinic.

Proteolysis-targeting chimera-doxorubicin conjugate nanoassemblies for dual treatment of EGFR-TKI sensitive and resistant non-small cell lung cancer

Proteolysis-targeting chimeras (PROTACs) have emerged as a promising strategy for targeted protein degradation and drug discovery. However, traditional PROTACs face inherent limitations and may also contribute to induce drug resistance. These challenges have driven the development of innovative strategies to overcome these obstacles. In current study, a PROTAC-DOX conjugates (PDCs) nanoassembly strategy was introduced to enhance tumor-targeting capability and overcome the drawbacks of conventional PROTACs. The designed PDC-S nanoparticles (PDC-S NPs) demonstrated potent anti-tumor activity against drug-resistant strains (IC50 = 4.7 µM) and improved in vivo efficacy (TGI = 76 %) against drug-sensitive strains, while minimizing side effects. Additionally, PDC-S NPs have great potential in tumor immunotherapy. This study provides a novel and promising strategy for the development of PROTAC-Drug Conjugates (PDCs). STATEMENT OF SIGNIFICANCE: We developed a PROTAC-DOX conjugates (PDCs) nanoassembly strategy to address the limitations of traditional PROTACs, such as poor solubility, low targeting specificity, and drug resistance. PDC-S NPs were constructed via self-assembly, which simplified preparation and minimized the toxicity typically associated with carrier-assisted delivery systems. The PDC-S NPs showed improved aqueous solubility and cellular uptake, resulting in efficient EGFR degradation in HCC827 cells. In vivo, PDC-S NPs accumulated at tumor sites via the EPR effect, resulting in enhanced anti-tumor potency with reduced side effects. Furthermore, PDC-S NPs induced immunogenic cell death (ICD) and suppressed PD-L1 and VEGF expression, highlighting great potential in tumor immunotherapy.

Sequential pH/GSH-responsive stealth nanoparticles for co-delivery of anti-PD-1 antibody and paclitaxel to enhance chemoimmunotherapy of lung cancer

Intravenously administered nanoparticles (NPs) often bind with plasma proteins, forming the protein corona that promotes rapid systemic clearance, a primary challenge in nanomedicine. In this study, we developed a pH- and GSH-sensitive "stealth" nanodelivery system, PTX@NPs-aPD1-IL, for sequential drug release. By using a biocompatible choline-based ionic liquid (IL) as the coating for NPs, the interaction and adsorption of NPs with serum proteins were reduced, achieving targeted delivery to the lung organ and increasing drug accumulation. In the weakly acidic extracellular tumor microenvironment (pH 6.5), the anti-PD-1 antibody (aPD-1) was first released to block the PD-1/PD-L1 pathway and restore the immunocidal function of T cells. In the highly reductive intracellular environment of tumor cells, the disulfide bonds were cleaved, causing NPs to rupture and release paclitaxel (PTX). It induced tumor cell apoptosis and triggered immunogenic cell death (ICD), promoted dendritic cells (DCs) maturation and activated T cells for chemo-immunotherapy. In the mouse orthotopic lung cancer model, PTX@NPs-aPD1-IL exhibited superior efficacy to other treatment groups at the same dose. This was due to the significantly increase in the release of immune factors, including TNF-α and IFN-γ, and the promotion of CD8+ T cells recruitment, which induced a stronger immune response, and thus enhanced the anti-lung cancer effect. In summary, PTX@NPs-aPD1-IL provided a promising strategy for effective chemo-immunotherapy for lung cancer through sequential release profile.

A review on recent advances in polymeric microneedle loading cells: Design strategies, fabrication technologies, transdermal application and challenges

Microneedle systems (MNs) loading living cells are a powerful platform to treat various previously incurable diseases in the era of precision medicine. Herein, an overview of recent advances in MN-based strategies for cell delivery is summarized, including material selection, design of morphological structures, and processing methods. We also systematically outlined the law of microstructural design relative to the structure-effective/function relationship in transdermal delivery or precision medicine and the design principles of cell microneedle (CMN). Furthermore, the representative works of precision treatments focusing on inflammatory skin diseases were tracked and discussed using CMN. Indeed, it highlights a practical path to solving the dilemma of cell therapy and raising the hope of precision medicine. However, there are still some challenges in developing CMN since they need multi-dimensional comprehensive properties, including mechanical properties, cell viability preservation, release, therapeutic effect, etc. The manuscript could provide insights into developing an innovative fit-to-purpose vehicle in cell therapy for interested researchers.

NIR Enhanced pH-Responsive Microneedles for Synergetic Therapy of Melanoma

Melanoma has emerged as a significant threat to human life and health. Microneedle (MN)-mediated transdermal drug delivery (TDD) has garnered attention in melanoma treatment for bypassing the first-pass effect. However, the propensity of melanoma to metastasize presents substantial challenges for MN mediated local treatment. Developing systemic therapies, such as immunotherapy in combination with TDD, is crucial for achieving effective melanoma treatment. Herein, a polyvinyl alcohol (PVA) MN-mediated multifunctional TDD system, designated MN@PDA@1-MT/CUR/DOX@HA (MN@PMCDH), was developed for synergetic chemotherapy/photothermal/immunotherapy of melanoma. PMCDH nanomedicines penetrate deep skin layers through MNs, accumulate at tumor sites guided by hyaluronic acid (HA), and selectively release drugs in response to the acidic tumor microenvironment and near-infrared (NIR) stimulation. Released curcumin (CUR) significantly enhances the efficacy of photothermal therapy (PTT) and chemotherapy, as well as improves the induction of immunogenic cell death (ICD) by increasing melanoma sensitivity to polydopamine (PDA)-mediated photothermal effects and doxorubicin (DOX). Moreover, the incorporation of 1-methyltryptophan (1-MT) to reverse the tumor immunosuppressive microenvironment can further enhance the effects of immunotherapy. In vitro studies revealed that the MN@PMCDH system can effectively induce ICD and inhibit tumor cell growth. Additionally, remarkable deep tumor cell inhibition effects are also achieved in 3D tumor models.

Drug Delivery System for Cancer Immunotherapy: Potential Roles, Challenge and Recent Advances

Immunotherapy has emerged as a pivotal advancement in oncological therapeutics, representing a paradigm shift from conventional treatment modalities including surgery, radiotherapy, and chemotherapy. This innovative approach demonstrates considerable clinical potential through its capacity to enhance systemic anti-tumor responses via active or passive immunomodulation. Compared to traditional therapies, immunotherapy offers distinct advantages such as broad applicability, rapid therapeutic onset, and reduced adverse effects. However, critical challenges persist in clinical implementation, particularly concerning treatment safety and efficacy optimization. Current limitations, including drug off-target effects and biological delivery barriers, frequently result in suboptimal therapeutic outcomes and severe complications such as autoimmune disorders and nonspecific inflammation. Recently advancements in drug delivery systems (DDS) present transformative solutions to these challenges. Sophisticated DDS platforms enable precise spatiotemporal delivery of tumor antigens, immunotherapeutic agents, and immunostimulatory molecules, thereby achieving targeted modulation of diverse immune cell populations. This technological innovation not only enhances therapeutic efficacy but also significantly mitigates adverse reactions, while facilitating synergistic combinations with conventional cancer treatments. In this review, we outline the application of new drug delivery platforms in major malignancies (including but not limited to melanoma, non-small cell lung cancer, hormone receptor-positive breast cancer, and hepatocellular carcinoma). We further propose evidence-based optimization strategies for next-generation delivery platforms, aiming to bridge the gap between preclinical development and clinical implementation in cancer immunotherapy.

A stimulus responsive microneedle-based drug delivery system for cancer therapy

The intricate nature of the tumor microenvironment (TME) results in the inefficient delivery of anticancer drugs within tumor tissues, significantly compromising the therapeutic effect of cancer treatment. To address this issue, transdermal drug delivery microneedles (MNs) with high mechanical strength have emerged. Such MNs penetrate the skin barrier, enabling efficient drug delivery to tumor tissues. This approach enhances drug bioavailability, while also mitigating concerns such as liver and kidney toxicity associated with intravenous and oral drug administration. Notably, stimulus responsive MNs designed for drug delivery have the capacity to respond to various biological signals and pathological changes. This adaptability enables them to exert therapeutic effects within the TME, exploiting biochemical variations and tailoring treatment strategies to suit tumor characteristics. The present review surveys recent advancements in responsive MN systems. This comprehensive analysis serves as a valuable reference for the prospective application of smart MN drug delivery systems in cancer therapy.

Engineering Hyaluronic Acid Microneedles Loaded with Mn2+ and Temozolomide for Topical Precision Therapy of Melanoma

Topical therapy has received worldwide attention for in situ tumors owing to its higher efficacy of drug delivery. Herein, this work reports a dissolvable multifunctional hyaluronic acid microneedles (HMNs) patch coloaded with temozolomide (TMZ) and MnCl2 (TMZ/MnCl2@HMN) for chemoimmunotherapy of melanoma. HMNs can ensure the stability of TMZ over time, and exhibit fewer side effects with a localized release way. In particular, TMZ not only promotes dendritic cell maturation by triggering immunogenic cell death in tumor cells, but also induces DNA damage that can further enhance the Mn2+-activated cGAS-STING (stimulator of interferon genes pathway). As a result, the TMZ/MnCl2@HMN multifunctional platform significantly inhibits lung metastases for melanoma, providing a practical strategy for precision therapy of melanoma.