Microneedle-Mediated Transdermal Delivery of Biopharmaceuticals

Nonfouling Core-Shell Microneedle for Sequential and Sustained Drug Release: Enhancing Synergistic Photothermal Chemotherapy in Melanoma Treatment

Melanoma is a highly aggressive and metastatic malignancy, where current treatment methods often result in damage to healthy tissues, suboptimal therapeutic outcomes, and immune-related side effects. Microneedles, as a drug delivery system, offer advantages such as localized administration, minimal invasiveness, and high delivery efficiency. In this study, we first synthesized tetradecyl-thiol-grafted PAMAM dendrimers, which significantly enhanced cellular uptake and enabled sustained release of doxorubicin (DOX), improving cumulative drug release efficiency. Based on this, we developed a core-shell structured zwitterionic polymer-based microneedle delivery system. The outer shell, loaded with the photothermal agent indocyanine green (ICG), achieved precise photothermal therapy under near-infrared irradiation, effectively targeting melanoma tissues. The inner core, composed of a zwitterionic polymer matrix, encapsulated DOX-loaded dendrimers, enabling controlled and prolonged drug release through gradual polymer swelling and dendrimer expansion. Experiments show that the microneedle drug delivery system based on PAMAM dendrimer grafted with tetradecyl mercaptan and zwitterionic polymer has excellent anti protein adsorption properties, and it can minimize the cytotoxicity of carrier and improve the efficiency of drug delivery. This system effectively inhibited tumor growth through synergistic photothermal-chemotherapy, reducing systemic toxicity and improving drug bioavailability. This microneedle platform provides a promising strategy for targeted and synergistic melanoma therapy, offering a high-efficiency and low-toxicity treatment alternative.

Development of polylactic acid microneedles for enhanced transdermal delivery of desmopressin peptides: A computational study

Addressing the challenges associated with traditional injection therapies, this research marks a significant advancement in personalized and targeted therapeutic interventions, offering improved efficacy, convenience, and safety for patients undergoing peptide-based treatments. This article presents a research study on the development and assessment of polylactic acid (PLA) microneedles for enhancing the delivery of proteins and peptides, mainly focusing on the transdermal administration of desmopressin. Using simulations with COMSOL multiphysics software, it has been shown that PLA microneedles have excellent durability and controlled drug delivery capabilities, which promise efficient and patient-friendly transdermal drug delivery applications. Computational modeling results highlighted the dynamic behavior of desmopressin flow within the microneedle system, emphasizing accelerated drug transport capabilities. The utilization of dissolving microneedles in this study underscores the potential of microneedle technology as a promising solution for enhancing transdermal drug permeation, particularly for hydrophilic and macromolecular substances like proteins and peptides, thus opening new avenues for effective drug delivery systems.

Carbohydrate-based polymer nanocarriers for environmentally friendly applications

Effective delivery of active substances and drugs is an important part of treatment. In order for a drug to work at the right place in the body, it must be transported there in the right way. For this reason, new carriers are being sought for active substances and drugs that can effectively deliver drugs to the target site without causing additional side effects. These include nanoparticles, microneedles, cubosomes and nanogels, among others. Recently, carriers based on biodegradable polymers such as hyaluronic acid or chitosan are becoming popular. In addition, modern carriers are designed to release the active ingredient in response to a specific agent. This paper reviews the literature from the past 5 years on novel delivery systems with medical, agricultural, food and cosmetic applications, with a special emphasis on the use of carbohydrate-based nanocarriers.

A review on microneedle patch as a delivery system for proteins/peptides and their applications in transdermal inflammation suppression

Transdermal delivery is one of the most recent modes of administration studied due to several shortfalls observed for intra-venous, and oral drug administrations. Among, microneedle-based transdermal delivery is the popular choice due to non-invasive procedure and minimal toxicological effects. Microneedle devices consist of micron scaled needle patch entrapped with the target specific drug molecules. Due to body's immune response and occasional pathogen attack, various inflammatory diseases are developed such as psoriasis, dermatitis, rashes, rheumatoid arthritis, gouty arthritis, and fibrosis. These inflammatory conditions can be treated by microneedle assisted transdermal delivery. Moreover, for localized suppression of pain and inflammation, various therapeutic peptides and proteins have been investigated. Although, these therapeutic agents can show reduced activity and undergo enzymatic degradation when administered orally or intra-venously. Hence, a microneedle-based delivery system can be used as an effective way to localize these peptides/proteins and reduce the inflammation. Herein, this review includes various microneedle fabrication methods for enhancing drug delivery for suppression of inflammation. Moreover, recent development in microneedle devices of peptide and protein delivery applications are discoursed. At last, future scope and challenges endured for preparing an efficient microneedle patch for peptide and protein delivery are also elaborated.

Marine algal polysaccharides for drug delivery applications: A review

In recent decades, there has been a growing interest in the use of polysaccharides that exhibit biological activity for a wide range of innovative applications. This is due to their nontoxicity, biodegradability, biocompatibility, and therapeutic properties. The diverse properties of polysaccharides derived from marine algae make them a promising strategy for the construction of drug delivery systems (DDSs). Marine algal polysaccharides can be utilized in regenerative medicine and gene delivery to facilitate the controlled release of therapeutic substances, which is a critical stage in the fight against severe diseases. Algal polysaccharide-based nanoparticles, microspheres, hydrogels, patches, and films are among the numerous controllable and sustained anti-inflammatory and anticancer DDSs that can be used due to the biological activities of these algal polymers. This review paper summarizes the advantages and applications of marine algal polysaccharides in DDSs (such as nanoparticles, microspheres, hydrogels, patches and films) as well as recent advances in drug delivery technologies, thereby providing valuable information for future research on drug delivery-based algal polysaccharides.

Transdermal delivery of resveratrol loaded solid lipid nanoparticle as a microneedle patch: a novel approach for the treatment of Parkinson's disease

Parkinson's disease (PD), affecting millions of people worldwide and expected to impact 10 million by 2030, manifests a spectrum of motor and non-motor symptoms linked to the decline of dopaminergic neurons. Current therapies manage PD symptoms but lack efficacy in slowing disease progression, emphasizing the urgency for more effective treatments. Resveratrol (RSV), recognized for its neuroprotective and antioxidative properties, encounters challenges in clinical use for PD due to limited bioavailability. Researchers have investigated lipid-based nanoformulations, specifically solid lipid nanoparticles (SLNs), to enhance RSV stability. Oral drug delivery via SLNs faces obstacles, prompting exploration into transdermal delivery using SLNs integrated with microneedles (MNs) for improved patient compliance. In this study, an RSV-loaded SLNs (RSV -SLNs) incorporated into the MN patch was developed for transdermal RSV delivery to improve its stability and patient compliance. Characterization studies demonstrated favorable physical properties of SLNs with a sustained drug release profile of 78.36 ± 0.74%. The developed MNs exhibited mechanical robustness and skin penetration capabilities. Ex vivo permeation studies displayed substantial drug permeation of 68.39 ± 1.4% through the skin. In an in vivo pharmacokinetic study, the RSV-SLNs delivered through MNs exhibited a significant increase in Cmax, Tmax, and AUC0 - t values, alongside a reduced elimination rate in blood plasma in contrast to the administration of pure RSV via MNs. Moreover, an in vivo study showcased enhanced behavioral functioning and increased brain antioxidant levels in the treated animals. In-vivo skin irritation study revealed no signs of irritation till 24 h which permits long-term MNs application. Histopathological analysis showed notable changes in the brain regions of the rat, specifically the striatum and substantia nigra, after the completion of the treatment. Based on these findings, the development of an RSV-SLN loaded MNs (RSVSNLMP) patch presents a novel approach, with the potential to enhance the drug's efficiency, patient compliance, and therapeutic outcomes for PD, offering a promising avenue for advanced PD therapy.

Black phosphorus nanosheets encapsulated microneedle for multifunctional therapy for androgenic alopecia

BACKGROUND

Androgenetic alopecia (AGA), a chronic and progressive disease, significantly impacts the patients' social, emotional, and mental well-being. Current treatment for AGA are mainly limited by drug side effects and the stratum corneum (SC) barrier of scalp.

RESULTS

To address these issues, we developed a microneedle (MN) system loaded with black phosphorus nanosheets (BP) encapsulating baicalin (BA), a natural ingredient, for effective treatment of AGA. We first fabricated BP-BA based on the BP properties of high drug loading capacity and excellent photothermal conversion efficiency. Upon 635 nm laser irradiation, BP-BA demonstrated efficient photothermal conversion to mild thermal of ~ 42 °C. This mild thermal effect controlled BA's stimuli-responsive release, enhanced cellular uptake, and effectively modulated gene expression in dihydrotestosterone-treated human dermal papilla cells, downregulating negative regulators such as SRD5A2, AR, DKK1, and TGFB1, while upregulating positive regulators like CTNNBIP1 and VEGFA. Furthermore, we encapsulated BP-BA to MN fabricating BP-BA@MNs to overcome the SC barrier. Compared with BP-BA@MNs without laser irradiation, BP-BA@MNs with laser irradiation significantly enhanced drug penetration into the subcutaneous area and accumulation at the follicular site. Importantly, BP-BA@MNs demonstrated synergistic efficacy against testosterone-induced AGA in vivo through combining BA chemotherapy, BP-mediated mild photothermal therapy, and MN delivery, as well as good biocompatibility and biosafety, and the underlying synergistic mechanism was elucidated in terms of follicular microenvironment reconstruction.

CONCLUSIONS

This combining BP mild photothermal and MN system is a promising approach for follicular targeted drug delivery, providing a multifunctional strategy for addressing the clinical needs of anti-AGA.

Advanced transdermal drug delivery system: A comprehensive review of microneedle technologies, novel designs, diverse applications, and critical challenges

Transdermal drug delivery presents numerous advantages over conventional administration routes, including non-invasiveness, enhanced patient adherence, circumvention of hepatic first-pass metabolism, self-administration capabilities, controlled release, and increased bioavailability. Nevertheless, the barrier function of stratum corneum limits this strategy to molecules possessing requisite physicochemical attributes. To expand the field of transdermal delivery, researchers have pioneered physical enhancement techniques, with micron-sized needles emerging as a particularly promising platform for the transdermal and intradermal delivery of therapeutic agents across a spectrum of molecular sizes. Microneedles function by disrupting the skin's integrity, generating microchannels that facilitate efficient drug permeation. This innovative technology boasts a captivating profile characterized by non-invasive drug delivery, enhanced efficacy and onset time, improved patient acceptability, self-administration possibilities, and precise dosing capabilities. Consequently, both academic institutions and industry have invested substantial resources in the development of microneedle systems for pharmaceutical delivery. This comprehensive review elucidates the multifaceted aspects of microneedle technology, encompassing its historical evolution, diverse materials, innovative designs, fabrication methodologies, and characterization techniques. The review extends to various microneedle types, including solid, hollow, coated, dissolving, swelling, and porous microneedles, as well as cutting-edge designs such as stimulus-responsive, iontophoresis-assisted, and bionic microneedles. Furthermore, we explore microneedle applications in vaccination, targeted delivery, and the administration of biologics, long-acting therapeutic agents, and cosmetics. Critical challenges in microneedle development, including dimensional considerations, safety concerns, acceptability factors, production scalability, regulatory hurdles, and sustainability issues, are thoroughly addressed, alongside a presentation of future prospects in this rapidly evolving field.

Beyond the Needle: Innovative Microneedle-Based Transdermal Vaccination

Vaccination represents a critical preventive strategy in the current global healthcare system, serving as an indispensable intervention against diverse pathogenic threats. Although conventional immunization relies predominantly on hypodermic needle-based administration, this method carries substantial limitations, including needle-associated fear, bloodborne pathogen transmission risks, occupational injuries among healthcare workers, waste management issues, and dependence on trained medical personnel. Microneedle technology has emerged as an innovative vaccine delivery system, offering convenient, effective, and minimally invasive administration. These microscale needle devices facilitate targeted antigen delivery to epidermal and dermal tissues, where abundant populations of antigen-presenting cells, specifically Langerhans and dermal dendritic cells, provide robust immunological responses. Multiple research groups have extensively investigated microneedle-based vaccination strategies. This transdermal delivery technique offers several advantages, notably circumventing cold-chain requirements and enabling self-administration. Numerous preclinical investigations and clinical trials have demonstrated the safety profile, immunogenicity, and patient acceptance of microneedle-mediated vaccine delivery across diverse immunization applications. This comprehensive review examines the fundamental aspects of microneedle-based immunization, including vaccination principles, transcutaneous immunization strategies, and microneedle-based transdermal delivery-including classifications, advantages, and barriers. Furthermore, this review addresses critical technical considerations, such as treatment efficacy, application methodologies, wear duration, dimensional optimization, manufacturing processes, regulatory frameworks, and sustainability considerations, followed by an analysis of the future perspective of this technology.

Microneedle-Assisted Delivery of Curcumin: Evaluating the Effects of Needle Length and Formulation

Dermal drug delivery presents a significant challenge for poorly soluble active compounds like curcumin, which often struggle to penetrate the skin barrier effectively. In this study, the dermal penetration efficacy of curcumin nanocrystals and bulk suspensions when applied to skin using microneedles of varying lengths-0.25 mm, 0.5 mm, and 1.0 mm-was investigated in an ex vivo porcine ear model. The findings revealed that all formulations, in conjunction with microneedle application, facilitated transepidermal penetration; however, the combination of microneedles and curcumin nanocrystals demonstrated the highest efficacy. Notably, the 1.0 mm microneedle length provided optimal penetration, significantly enhancing curcumin delivery compared with bulk suspensions alone. Additionally, even the use of 0.25 mm microneedles resulted in a high level of efficiency, indicating that shorter microneedles can still effectively facilitate drug delivery. Overall, this study underscores the potential of microneedle technology in improving the transepidermal absorption of poorly soluble actives like curcumin, suggesting that the integration of nanocrystals with microneedles could enhance the therapeutic effects of topical curcumin applications.

Self-assembled hyaluronic acid nanoparticles delivered by polymeric microneedles for targeted and long-acting therapy of psoriasis

Psoriasis is an autoimmune-driven inflammatory skin disease, clinically characterized by skin thickening, erythema, and scaling, significantly impacting patients' life quality and mental health. Clinically, oral pill or injection of methotrexate (MTX) formulation is a common route for psoriasis therapy, while both methods often cause undesired toxicity due to systemic administration, and limit patient compliance because of the frequent-dosing requirement. Here, we introduce a dissolvable microneedle (MN) patch made of polyvinyl alcohol (PVA) that incorporates self-assembled hyaluronic acid (HA) nanoparticles (NPs) conjugating MTX, which is designed for treating skin diseases, offering reduced adverse effects and improved patient adherence through its targeted and long-acting properties. Upon transdermal delivery via polymeric MNs, the HA-based therapeutic NPs actively target to the inflammatory skin cells via the interaction of HA group with CD44 protein that is highly expressed on the cell membrane in the psoriatic skin. Moreover, the HA-based NPs undergo slow dissociation, thereby achieving sustained release of the MTX drug at the lesion site over 7 days. Due to the favorite features, in the imiquimod (IMQ)-induced psoriatic mouse, only one application of the polymeric MN patch achieves diminished epidermal hyperplasia, and reduced inflammatory factors expression, ultimately improving the psoriasis-like skin condition in vivo.

Microneedle patches: a new vantage point for diabetic wound treatments

Microneedle patches have emerged as a promising approach for diabetic wound healing by enabling the targeted delivery of therapeutic agents such as stem cells and their derived exosomes, as well as localized delivery of bioactive moieties. These patches offer a non-invasive and efficient method for administering therapeutic payloads directly to the site of the wound, bypassing systemic circulation and minimizing potential side effects. The targeted delivery of stem cells holds immense potential for promoting tissue regeneration and accelerating wound healing in diabetic patients. Similarly, the localized delivery of stem cell-derived exosomes, which are known for their regenerative and anti-inflammatory properties, can enhance the healing process. Furthermore, microneedle patches enable the precise and controlled release of bioactive moieties, such as growth factors and cytokines, directly to the wound site, creating a conducive microenvironment for tissue repair and regeneration. The challenges associated with microneedle patches for diabetic wound healing are multifaceted. Biocompatibility issues, variability in skin characteristics among diabetic patients, regulatory hurdles, scalability, cost considerations, long-term stability, and patient acceptance and compliance all present significant barriers to the widespread adoption and optimization of microneedle technology in clinical practice. Overcoming these challenges will require collaborative efforts from various stakeholders to advance the field and address critical gaps in research and development. Ongoing research focuses on enhancing the biocompatibility and mechanical properties of microneedle materials, developing customizable technologies for personalized treatment approaches, integrating advanced functionalities such as sensors for real-time monitoring, and improving patient engagement and adherence through education and support mechanisms. These advancements have the potential to improve diabetic wound management by providing tailored and precise therapies that promote faster healing and reduce complications. This review explores the current landscape of microneedle patches in the context of diabetic wound management, highlighting both the challenges that need to be addressed and future perspectives for this innovative treatment modality.

A core-shell microneedle system for stable fibroblast delivery in cell-based therapies

Human cells, such as fibroblasts and particularly human mesenchymal stem cells (hMSCs), represent a promising and effective therapeutic tool for a range of cell-based therapies used to treat various diseases. The effective delivery of therapeutic cells remains a challenge due to limitations in targeting, invasiveness, and cell viability. To address these challenges, we developed a microneedle (MN) system for minimally invasive cell delivery with high cellular stability. The MN system comprises a core of gelatin methacryloyl (GelMA) hydrogel embedded with fibroblasts, encased in a polylactic-co-glycolic acid (PLGA) shell that enhances structural integrity for efficient skin penetration. The fabrication process involves UV-crosslinking of the GelMA hydrogel with cells, optimizing both cell encapsulation and structural strength. This MN system achieves over 80% cell viability after seven days in vitro, with the conventional GelMA formulation providing superior stability and cellular outcomes. This platform's ability to ensure sustained cell viability presents promising implications for future applications in regenerative medicine, wound healing, and localized treatments for skin conditions. This MN system opens new avenues for cell-based therapies, offering a versatile and scalable solution for therapeutic cell delivery.

Prevention of early thrombosis in transplanted vein model by encapsulation with tirofiban microneedle drug delivery system

Early thrombosis following coronary artery bypass grafting (CABG) surgery leads to perioperative myocardial infarction, which causes difficulties for clinicians and patients. Moreover, once perioperative myocardial infarction occurs, the mortality rate is extremely high. In recent years, microneedle (MN) drug delivery systems have become a research hotspot with broad clinical application prospects. These systems are capable of achieving sustained, safe, and painless local drug release. In cardiovascular applications, MNs maximize local anticoagulant effects, inhibit endometrial hyperplasia, and reduce systemic side effects. We speculate that a MN drug delivery system can be used to target transplanted veins to inhibit their thrombosis and reduce the incidence of perioperative myocardial infarction after CABG surgery. Therefore, this study developed a hyaluronic acid MN patch loaded with tirofiban and conducted preliminary physicochemical tests. The safety, efficacy, biocompatibility, and targeting of the MN system were evaluated usingin vitroandin vivoexperiments using a jugular vein transplantation model. The results indicate that the MN system has excellent physical properties, safety, effectiveness, biocompatibility, and strong targeting, which can effectively inhibit early local thrombus formation. In addition, the observation of early postoperative endometrial hyperplasia activation provides a foundation for future research.

Mesenchymal stromal cells-derived small extracellular vesicles protect against UV-induced photoaging via regulating pregnancy zone protein

Ultraviolet (UV) radiation is the primary extrinsic factor in skin aging, contributing to skin photoaging, actinic keratosis (AK), and even squamous cell carcinoma (SCC). Currently, the beneficial role of mesenchymal stromal cell-derived small extracellular vesicles (MSC-sEVs) in cutaneous wound healing has been widely reported, but the field of photoaging remains to be explored. Our results suggested that human umbilical cord MSC-derived sEVs (hucMSC-sEVs) intervention could effectively alleviate skin photoaging phenotypes in vivo and in vitro, including ameliorating UV-induced histopathological changes in the skin and inhibiting oxidative stress and collagen degradation in dermal fibroblasts (DFs). Mechanistically, pretreatment with hucMSC-sEVs reversed UVA-induced down-regulation of pregnancy zone protein (PZP) in DFs, and achieved photoprotection by inhibiting matrix metalloproteinase-1 (MMP-1) expression and reducing DNA damage. Clinically, a significant decrease in PZP in AK and SCC in situ samples was observed, while a rebound appeared in the invasive SCC samples. Collectively, our findings reveal the effective role of hucMSC-sEVs in regulating PZP to combat photoaging and provide new pre-clinical evidence for the potential development of hucMSC-sEVs as an effective skin photoprotective agent.

Transdermal Drug Delivery Systems (TDDS): Recent Advances and Failure Modes

Transdermal drug delivery systems (TDDS), commonly refered to as "patches", present a nonintrusive technique to provide medication without the need for invasive procedures. These products adhere to the skin and gradually release a specific dosage of medicine at a defined rate into the bloodstream. Compared with other methods of drug delivery, TDDS offer benefits such as reduced invasiveness, convenience for patients, and avoidance of the metabolic processes that occur when drugs are orally consumed. Throughout time, TDDS have been used to provide medications for various medical conditions (such as nicotine, fentanyl, nitroglycerin, and clonidine), and their potential for delivering biologics is currently being explored. This review investigates the current literature on the drug delivery efficacy of medical TDDS through the transdermal route. Additionally, the review addresses potential risks and failure modes associated with TDDS design and development as well as strategies for mitigating such risks. A thorough understanding of failure modes provides a blueprint to mitigate failure and produce high-quality efficacious therapeutics.

The role of liquid-liquid phase separation in the disease pathogenesis and drug development

Misfolding and aggregation of specific proteins are associated with liquid-liquid phase separation (LLPS), and these protein aggregates can interfere with normal cellular functions and even lead to cell death, possibly affecting gene expression regulation and cell proliferation. Therefore, understanding the role of LLPS in disease may help to identify new mechanisms or therapeutic targets and provide new strategies for disease treatment. There are several ways to disrupt LLPS, including screening small molecules or small molecule drugs to target the upstream signaling pathways that regulate the LLPS process, selectively dissolve and destroy RNA droplets or protein aggregates, regulate the conformation of mutant protein, activate the protein degradation pathway to remove harmful protein aggregates. Furthermore, harnessing the mechanism of LLPS can improve drug development, including preparing different kinds of drug delivery carriers (microneedles, nanodrugs, imprints), regulating drug internalization and penetration behaviors, screening more drugs to overcome drug resistance and enhance receptor signaling. This review initially explores the correlation between aberrant LLPS and disease, highlighting the pivotal role of LLPS in preparing drug development. Ultimately, a comprehensive investigation into drug-mediated regulation of LLPS processes holds significant scientific promise for disease management.

Nanomaterial-Enhanced Microneedles: Emerging Therapies for Diabetes and Obesity

Drug delivery systems (DDS) have improved therapeutic agent administration by enhancing efficacy and patient compliance while minimizing side effects. They enable targeted delivery, controlled release, and improved bioavailability. Transdermal drug delivery systems (TDDS) offer non-invasive medication administration and have evolved to include methods such as chemical enhancers, iontophoresis, microneedles (MN), and nanocarriers. MN technology provides innovative solutions for chronic metabolic diseases like diabetes and obesity using various MN types. For diabetes management, MNs enable continuous glucose monitoring, diabetic wound healing, and painless insulin delivery. For obesity treatment, MNs provide sustained transdermal delivery of anti-obesity drugs or nanoparticles (NPs). Hybrid systems integrating wearable sensors and smart materials enhance treatment effectiveness and patient management. Nanotechnology has advanced drug delivery by integrating nano-scaled materials like liposomes and polymeric NPs with MNs. In diabetes management, glucose-responsive NPs facilitate smart insulin delivery. At the same time, lipid nanocarriers in dissolving MNs enable extended release for obesity treatment, enhancing drug stability and absorption for improved metabolic disorder therapies. DDS for obesity and diabetes are advancing toward personalized treatments using smart MN enhanced with nanomaterials. These innovative approaches can enhance patient outcomes through precise drug administration and real-time monitoring. However, widespread implementation faces challenges in ensuring biocompatibility, improving technologies, scaling production, and obtaining regulatory approval. This review will present recent advances in developing and applying nanomaterial-enhanced MNs for diabetes and obesity management while also discussing the challenges, limitations, and future perspectives of these innovative DDS.

Polymeric Microneedle Drug Delivery Systems: Mechanisms of Treatment, Material Properties, and Clinical Applications-A Comprehensive Review

Our comprehensive review plunges into the cutting-edge advancements of polymeric microneedle drug delivery systems, underscoring their transformative potential in the realm of transdermal drug administration. Our scrutiny centers on the substrate materials pivotal for microneedle construction and the core properties that dictate their efficacy. We delve into the distinctive interplay between microneedles and dermal layers, underscoring the mechanisms by which this synergy enhances drug absorption and precision targeting. Moreover, we examine the acupoint-target organ-ganglion nexus, an innovative strategy that steers drug concentration to specific targets, offering a paradigm for precision medicine. A thorough analysis of the clinical applications of polymeric microneedle systems is presented, highlighting their adaptability and impact across a spectrum of therapeutic domains. This review also accentuates the systems' promise to bolster patient compliance, attributed to their minimally invasive and painless mode of drug delivery. We present forward-looking strategies aimed at optimizing stimulation sites to amplify therapeutic benefits. The anticipation is set for the introduction of superior biocompatible materials with advanced mechanical properties, customizing microneedles to cater to specialized clinical demands. In parallel, we deliberate on safety strategies aimed at boosting drug loading capacities and solidifying the efficacy of microneedle-based therapeutics. In summation, this review accentuates the pivotal role of polymeric microneedle technology in contemporary healthcare, charting a course for future investigative endeavors and developmental strides within this burgeoning field.

Recent progress of microneedles in transdermal immunotherapy: A review

Since human skin is an immune organ, a large number of immune cells are distributed in the epidermis and the dermis of the skin. Transdermal immunotherapy shows great therapeutic advantages in innate immunotherapy and adaptive immunotherapy. To solve the problem that macromolecules are difficult to penetrate into the skin, the microneedle technology can directly break through the skin barrier using micron-sized needles in a non-invasive and painless way for transdermal drug delivery. Therefore, it is considered to be an effective technology to increase drug transdermal absorption. In this review, the types of preparation, the combinations with different techniques and the mechanisms of microneedles in transdermal immunotherapy were summarized. Compared with traditional immunotherapy like intramuscular injection and subcutaneous injection, the microneedle has many advantages in transdermal immunotherapy, such as reducing patient pain, enhancing vaccine stability, and inducing stronger immune responses. Although there are still some limitations to be solved, the application of microneedle technology in transdermal immunotherapy is undoubtedly a promising means of drug delivery.

Advances in metformin-delivery systems for diabetes and obesity management

Metformin is a medication that is commonly prescribed to manage type 2 diabetes. It has been used for more than 60 years and is highly effective in lowering blood glucose levels. Recent studies indicate that metformin may have additional medical benefits beyond treating diabetes, revealing its potential therapeutic uses. Oral medication is commonly used to administer metformin because of its convenience and cost-effectiveness. However, there are challenges in optimizing its effectiveness. Gastrointestinal side effects and limitations in bioavailability have led to the underutilization of metformin. Innovative drug-delivery systems such as fast-dissolving tablets, micro/nanoparticle formulations, hydrogel and microneedles have been explored to optimize metformin therapy. These strategies enhance metformin dosage, targeting, bioavailability and stability, and provide personalized treatment options for improved glucose homeostasis, antiobesity and metabolic health benefits. Developing new delivery systems for metformin shows potential for improving therapeutic outcomes, broadening its applications beyond diabetes management and addressing unmet medical needs in various clinical settings. However, it is important to improve drug-delivery systems, addressing issues such as complexity, cost, biocompatibility, stability during storage and transportation, loading capacity, required technologies and biomaterials, targeting precision and regulatory approval. Addressing these limitations is crucial for effective, safe and accessible drug delivery in clinical practice. In this review, recent advances in the development and application of metformin-delivery systems for diabetes and obesity are discussed.

Novel Administration Routes, Delivery Vectors, and Application of Vaccines Based on Biotechnologies: A Review

Traditional vaccines can be classified into inactivated vaccines, live attenuated vaccines, and subunit vaccines given orally or via intramuscular (IM) injection or subcutaneous (SC) injection for the prevention of infectious diseases. Recently, recombinant protein vaccines, DNA vaccines, mRNA vaccines, and multiple/alternative administering route vaccines (e.g., microneedle or inhalation) have been developed to make vaccines more secure, effective, tolerable, and universal for the public. In addition to preventing infectious diseases, novel vaccines have currently been developed or are being developed to prevent or cure noninfectious diseases, including cancer. These vaccine platforms have been developed using various biotechnologies such as viral vectors, nanoparticles, mRNA, recombination DNA, subunit, novel adjuvants, and other vaccine delivery systems. In this review, we will explore the development of novel vaccines applying biotechnologies, such as vaccines based on novel administration routes, vaccines based on novel vectors, including viruses and nanoparticles, vaccines applied for cancer prevention, and therapeutic vaccines.

Microneedling in Dermatology: A Comprehensive Review of Applications, Techniques, and Outcomes

Microneedling, also known as collagen induction therapy, is a minimally invasive dermatological procedure that has gained widespread popularity for treating various skin conditions, including acne scars, wrinkles, hyperpigmentation, and stretch marks. By creating controlled micro-injuries in the skin, microneedling stimulates the body's natural healing processes, resulting in increased collagen and elastin production, essential for maintaining skin elasticity and firmness. Over the past few decades, microneedling has evolved significantly, with advancements such as automated devices, radiofrequency microneedling, and combination therapies enhancing its effectiveness and safety profile. This comprehensive review explores the mechanisms of action, various techniques, and clinical applications of microneedling, highlighting its advantages over other skin rejuvenation methods. The review also examines patient satisfaction, safety considerations, and potential complications, providing a balanced perspective on its clinical utility. Furthermore, the discussion includes future directions in microneedling technology and research, focusing on emerging innovations and potential new applications. As the field advances, microneedling is poised to play an increasingly important role in aesthetic medicine, offering a reliable and effective solution for skin rejuvenation and beyond. This review is a valuable resource for healthcare professionals, guiding the optimization of microneedling practices and informing future research efforts.

Novel Drug Delivery Systems: An Important Direction for Drug Innovation Research and Development

The escalating demand for enhanced therapeutic efficacy and reduced adverse effects in the pharmaceutical domain has catalyzed a new frontier of innovation and research in the field of pharmacy: novel drug delivery systems. These systems are designed to address the limitations of conventional drug administration, such as abbreviated half-life, inadequate targeting, low solubility, and bioavailability. As the disciplines of pharmacy, materials science, and biomedicine continue to advance and converge, the development of efficient and safe drug delivery systems, including biopharmaceutical formulations, has garnered significant attention both domestically and internationally. This article presents an overview of the latest advancements in drug delivery systems, categorized into four primary areas: carrier-based and coupling-based targeted drug delivery systems, intelligent drug delivery systems, and drug delivery devices, based on their main objectives and methodologies. Additionally, it critically analyzes the technological bottlenecks, current research challenges, and future trends in the application of novel drug delivery systems.

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.

Current approaches in smart nano-inspired drug delivery: A narrative review

Background and Aim

The traditional drug delivery approach involves systemic administration of a drug that could be nonspecific in targeting, low on efficacy, and with severe side-effects. To address such challenges, the field of smart drug delivery has emerged aiming at designing and developing delivery systems that can target specific cells, tissues, and organs and have minimal off-target side-effects.

Methods

A literature search was done to collate papers and reports about the currently available various strategies for smart nano-inspired drug delivery. The databases searched were PubMed, Scopus, and Google Scholar. Based on selection criteria, the most pertinent and recent items were included.

Results

Smart drug delivery is a cutting-edge revolutionary intervention in modern medicines to ensure effective and safe administration of therapeutics to target sites. These hold great promise for targeted and controlled delivery of therapeutic agents to improve the efficacy with reduced side-effects as compared to the conventional drug delivery approaches. Current smart drug delivery approaches include nanoparticles, liposomes, micelles, and hydrogels, each with its own advantages and limitations. The success of these delivery systems lies in engineering and designing them, and optimizing their pharmacokinetics and pharmacodynamics properties.

Conclusion

Development of drug delivery systems that can get beyond various physiological and clinical barriers, as observed in conventionally administered chemotherapeutics, has been possible through recent advancements. Using multifunctional targeting methodologies, smart drug delivery tries to localize therapy to the target location, reduces cytotoxicity, and improves the therapeutic index. Rapid advancements in research and development in smart drug delivery provide wider and more promising avenues to guarantee a better healthcare system, improve patient outcomes, and achieve higher levels of effective medical interventions like personalized medicine.

Efficient Loading and Sustained Delivery of Methotrexate Using a Tip-Swellable Microneedle Array Patch for Psoriasis Treatment

Methotrexate (MTX), a primary treatment for moderate to severe psoriasis, is limited in clinical use due to suboptimal results and severe side effects from subcutaneous (SC) injection and oral administration. Microneedles offer a promising alternative for direct MTX delivery to targeted skin lesions, but issues such as drug wastage, dosage inaccuracy, and limited drug residence time in the lesions remain. This study introduces a tip-swellable microneedle array patch (TSMAP) using photo-cross-linked methacrylated hyaluronic acid (MeHA) and biocompatible resin for effective MTX loading and sustained delivery. A two-cast micromolding with vacuum drying is employed to concentrate cross-linked MeHA in about 30% of the needle's height at the tip, thereby ensuring that only the TSMAP tip swells. Efficient MTX loading into TSMAP tips is achieved through a 30 s drug solution immersion and 10 min drying, potentially minimizing drug waste from incomplete skin insertion due to skin elasticity. The MTX-loaded TSMAP effectively penetrates both porcine and psoriasis-like mouse skin with its tips detaching from the resin substrate and embedding deeply into the skin tissue, thereby functioning as a drug release reservoir. TSMAP significantly prolongs drug retention in skin compared with SC injection and dissolvable microneedles. The in vivo study demonstrates that TSMAP-mediated MTX delivery substantially enhances therapeutic outcomes in alleviating psoriasis symptoms and downregulating psoriasis-associated cytokines, outperforming oral administration, SC injection, and dissolvable microneedles. Thus, TSMAP could offer an efficient and user-friendly alternative for drug administration in the treatment of various skin diseases.

3D Printing of Biodegradable Polymeric Microneedles for Transdermal Drug Delivery Applications

Microneedle (MN) technology is an optimal choice for the delivery of drugs via the transdermal route, with a minimally invasive procedure. MN applications are varied from drug delivery, cosmetics, tissue engineering, vaccine delivery, and disease diagnostics. The MN is a biomedical device that offers many advantages including but not limited to a painless experience, being time-effective, and real-time sensing. This research implements additive manufacturing (AM) technology to fabricate MN arrays for advanced therapeutic applications. Stereolithography (SLA) was used to fabricate six MN designs with three aspect ratios. The MN array included conical-shaped 100 needles (10 × 10 needle) in each array. The microneedles were characterized using optical and scanning electron microscopy to evaluate the dimensional accuracy. Further, mechanical and insertion tests were performed to analyze the mechanical strength and skin penetration capabilities of the polymeric MN. MNs with higher aspect ratios had higher deformation characteristics suitable for penetration to deeper levels beyond the stratum corneum. MNs with both 0.3 mm and 0.4 mm base diameters displayed consistent force-displacement behavior during a skin-equivalent penetration test. This research establishes guidelines for fabricating polymeric MN for high-accuracy and low-cost 3D printing.

Fabrication Technology of Self-Dissolving Sodium Hyaluronate Gels Ultrafine Microneedles for Medical Applications with UV-Curing Gas-Permeable Mold

Microneedles are of great interest in diverse fields, including cosmetics, drug delivery systems, chromatography, and biological sensing for disease diagnosis. Self-dissolving ultrafine microneedles of pure sodium hyaluronate hydrogels were fabricated using a UV-curing TiO2-SiO2 gas-permeable mold polymerized by sol-gel hydrolysis reactions in nanoimprint lithography processes under refrigeration at 5 °C, where thermal decomposition of microneedle components can be avoided. The moldability, strength, and dissolution behavior of sodium hyaluronate hydrogels with different molecular weights were compared to evaluate the suitability of ultrafine microneedles with a bottom diameter of 40 μm and a height of 80 μm. The appropriate molecular weight range and formulation of pure sodium hyaluronate hydrogels were found to control the dissolution behavior of self-dissolving ultrafine microneedles while maintaining the moldability and strength of the microneedles. This fabrication technology of ultrafine microneedles expands their possibilities as a next-generation technique for bioactive gels for controlling the blood levels of drugs and avoiding pain during administration.

Fabrication of dissolving microneedles for transdermal delivery of protein and peptide drugs: polymer materials and solvent casting micromoulding method

Proteins and peptides are rapidly developing pharmaceutical products and are expected to continue growing in the future. However, due to their nature, their delivery is often limited to injection, with drawbacks such as pain and needle waste. To overcome these limitations, microneedles technology is developed to deliver protein and peptide drugs through the skin. One type of microneedles, known as dissolving microneedles, has been extensively studied for delivering various proteins and peptides, including ovalbumin, insulin, bovine serum albumin, polymyxin B, vancomycin, and bevacizumab. This article discusses polymer materials used for fabricating dissolving microneedles, which are poly(vinylpyrrolidone), hyaluronic acid, poly(vinyl alcohol), carboxymethylcellulose, GantrezTM, as well as other biopolymers like pullulan and ulvan. The paper is focused solely on solvent casting micromoulding method for fabricating dissolving microneedles containing proteins and peptides, which will be divided into one-step and two-step casting micromoulding. Additionally, future considerations in the market plan for dissolving microneedles are discussed in this article.

Cubosomes-assisted transdermal delivery of doxorubicin and indocyanine green for chemo-photothermal combination therapy of melanoma

Melanoma is a highly aggressive form of skin cancer with limited therapeutic options. Chemo-photothermal combination therapy has demonstrated potential for effectively treating melanoma, and transdermal administration is considered the optimal route for treating skin diseases due to its ability to bypass first-pass metabolism and enhance drug concentration. However, the stratum corneum presents a formidable challenge as a significant barrier to drug penetration in transdermal drug delivery. Lipid-nanocarriers, particularly cubosomes, have been demonstrated to possess significant potential in augmenting drug permeation across the stratum corneum. Herein, cubosomes co-loaded with doxorubicin (DOX, a chemotherapeutic drug) and indocyanine green (ICG, a photothermal agent) (DOX-ICG-cubo) transdermal drug delivery system was developed to enhance the therapeutic efficiency of melanoma by improving drug permeation. The DOX-ICG-cubo showed high encapsulation efficiency of both DOX and ICG, and exhibited good stability under physiological conditions. In addition, the unique cubic structure of the DOX-ICG-cubo was confirmed through transmission electron microscopy (TEM) images, polarizing microscopy, and small angle X-ray scattering (SAXS). The DOX-ICG-cubo presented high photothermal conversion efficiency, as well as pH and thermo-responsive DOX release. Notably, the DOX-ICG-cubo exhibited enhanced drug permeation efficiency, good biocompatibility, and improved in vivo anti-melanoma efficacy through the synergistic effects of chemo-photothermal therapy. In conclusion, DOX-ICG-cubo presented a promising strategy for melanoma treatment.

Long-acting microneedle formulations

The minimally-invasive and painless nature of microneedle (MN) application has enabled the technology to obviate many issues with injectable drug delivery. MNs not only administer therapeutics directly into the dermal and ocular space, but they can also control the release profile of the active compound over a desired period. To enable prolonged delivery of payloads, various MN types have been proposed and evaluated, including dissolving MNs, polymeric MNs loaded or coated with nanoparticles, fast-separable MNs hollow MNs, and hydrogel MNs. These intricate yet intelligent delivery platforms provide an attractive approach to decrease side effects and administration frequency, thus offer the potential to increase patient compliance. In this review, MN formulations that are loaded with various therapeutics for long-acting delivery to address the clinical needs of a myriad of diseases are discussed. We also highlight the design aspects, such as polymer selection and MN geometry, in addition to computational and mathematical modeling of MNs that are necessary to help streamline and develop MNs with high translational value and clinical impact. Finally, up-scale manufacturing and regulatory hurdles along with potential avenues that require further research to bring MN technology to the market are carefully considered. It is hoped that this review will provide insight to formulators and clinicians that the judicious selection of materials in tandem with refined design may offer an elegant approach to achieve sustained delivery of payloads through the simple and painless application of a MN patch.

Recent Advances in Formulations for Long-Acting Delivery of Therapeutic Peptides

Recent preclinical and clinical studies have focused on the active area of therapeutic peptides due to their high potency, selectivity, and specificity in treating a broad range of diseases. However, therapeutic peptides suffer from multiple disadvantages, such as limited oral bioavailability, short half-life, rapid clearance from the body, and susceptibility to physiological conditions (e.g., acidic pH and enzymolysis). Therefore, high peptide dosages and dose frequencies are required for effective patient treatment. Recent innovations in pharmaceutical formulations have substantially improved therapeutic peptide administration by providing the following advantages: long-acting delivery, precise dose administration, retention of biological activity, and improvement of patient compliance. This review discusses therapeutic peptides and challenges in their delivery and explores recent peptide delivery formulations, including micro/nanoparticles (based on lipids, polymers, porous silicon, silica, and stimuli-responsive materials), (stimuli-responsive) hydrogels, particle/hydrogel composites, and (natural or synthetic) scaffolds. This review further covers the applications of these formulations for prolonged delivery and sustained release of therapeutic peptides and their impact on peptide bioactivity, loading efficiency, and (in vitro/in vivo) release parameters.

Transdermal drug delivery via microneedles for musculoskeletal systems

As the population is ageing and lifestyle is changing, the prevalence of musculoskeletal (MSK) disorders is gradually increasing with each passing year, posing a serious threat to the health and quality of the public, especially the elderly. However, currently prevalent treatments for MSK disorders, mainly administered orally and by injection, are not targeted to the specific lesion, resulting in low efficacy along with a series of local and systemic adverse effects. Microneedle (MN) patches loaded with micron-sized needle array, combining the advantages of oral administration and local injection, have become a potentially novel strategy for the administration and treatment of MSK diseases. In this review, we briefly introduce the basics of MNs and focus on the main characteristics of the MSK systems and various types of MN-based transdermal drug delivery (TDD) systems. We emphasize the progress and broad applications of MN-based transdermal drug delivery (TDD) for MSK systems, including osteoporosis, nutritional rickets and some other typical types of arthritis and muscular damage, and in closing summarize the future prospects and challenges of MNs application.

Bacterial cellulose-based composites as vehicles for dermal and transdermal drug delivery: A review

In recent years, a significant amount of drugs have been taken orally, which are not as effective as desired. To solve this problem, bacterial cellulose-based dermal/transdermal drug delivery systems (BC-DDSs) with unique properties such as cell compatibility, hemocompatibility, tunable mechanical properties, and the ability to encapsulate various therapeutic agents with the controlled release have been introduced. A BC-dermal/transdermal DDS reduces first-pass metabolism and systematic side effects while improving patient compliance and dosage effectiveness by controlling drug release through the skin. The barrier function of the skin, especially the stratum corneum, can interfere with drug delivery. Few drugs can pass through the skin to reach effective concentrations in the blood to treat diseases. Due to their unique physicochemical properties and high potential to reduce immunogenicity and improve bioavailability, BC-dermal/transdermal DDSs are widely used to deliver various types of drugs for disease treatment. In this review, we describe the different types of BC-dermal/ transdermal DDSs, along with a critical discussion of the advantages and disadvantages of these systems. After the general presentation, the review is focused on recent advances in the preparation and applications of BC-based dermal/transdermal DDSs in various types of disease treatment.