Improved Therapeutic Efficiency against Obesity through Transdermal Drug Delivery Using Microneedle Arrays

Hyaluronic acid-based hesperidin nanostructured lipid carriers loaded dissolving microneedles: A localized delivery approach loaded for the management of obesity

Obesity, a persistent imbalance of calories, has become one of the major clinical factors that result in many metabolic disorders. Despite excellent anti-obesity properties, the poor aqueous solubility of hesperidin (HES), a flavonoid, hampers its applicability. To resolve this issue and conquer oral administration's drawbacks, our study has concentrated on encapsulating HES in nanostructured lipid carriers (NLCs) and incorporating the NLCs into microneedles (MNs). By developing HES-loaded NLCs (HES-NLCs) with hyaluronic acid (HA) as a base design to form a microneedle patch (HES-NLCMNP), the study aimed to increase the stability and bioavailability of HES and provide an innovative way for the management of obesity. HES-NLCs were loaded to the microneedle, to promote anti-obesity activity. The microneedle tip, which has been composed of HA, will act as a biodegradable polymer that could effectively deliver the activity of HES-NLC to the blood stream. Furthermore, the base of the microneedle patch composed of polyvinyl alcohol (PVA) offered excellent flexibility, releasing HES and providing resistance to any adverse effects. Analysis revealed that the prepared HES-NLCs have desirable physical characteristics with an extended-release profile. The optimised NLC formulation (F3F) was later incorporated into HA-base-designed MNs that demonstrated mechanical solid integrity and effective skin penetration. In vivo pharmacokinetics significantly improved all parameters with a reduced elimination rate. Physiological, haematological, and antioxidant markers improved in treated rats, with histopathological analysis showing significant tissue alterations. The results suggest that HES-NLCMNP is a promising platform to improve drug effectiveness, patient compliance, and treatment outcomes for obesity.

Role of Microneedles for Improved Treatment of Obesity: Progress and Challenges

Obesity is a global metabolic health epidemic characterized by excessive lipid and fat accumulation, leading to severe conditions such as diabetes, cancer, and cardiovascular disease. Immediate attention and management of obesity-related health risks are most warranted. The imbalance between fat absorption, metabolic rate, and environmental and genetic factors is responsible for obesity. Treatment typically involves lifestyle modifications, pharmacotherapy, and surgery. While lifestyle changes are crucial, effective treatment often necessitates medication as a preferred adjunct strategy. However, medications commonly used, such as oral pharmacotherapy, often show side effects due to systemic exposure and, thus, may not effectively target the intended areas, leading to drug loss. On the other hand, transdermal administration of drugs with microneedle (MN)-based technologies, a painless drug delivery approach with patient compliance, is gaining interest as an alternative obesity treatment, as it directly targets adipose tissue via local delivery, minimizing system exposure and dose reduction. This Review addresses the pathophysiology of obesity, current treatment strategies, challenges in the treatment of obesity using conventional formulations, the importance of the use of nano-based medications through transdermal delivery, and the use of MNs as a promising platform for the effective delivery of nanoparticle-based anti-obesity medications. The potential of combining MNs with stimuli-responsive and non-responsive adjuvant therapies to enhance treatment efficacy and patient outcomes is explored. In addition, the limitations and future perspectives related to the use of MNs for obesity are addressed to highlight the transformative potential of this technology for obesity management. MNs hold promise in precisely delivering anti-obesity drugs while requiring lower dosages and minimizing side effects compared to conventional oral or injectable therapies and ultimately improving the quality of life for individuals struggling with obesity and its associated comorbidities.

Design and development of a soluble PDA-Emodin-PVP-MN patch and its anti-obesity effect in rats

Emodin has been proven to have weight-reducing and lipid-lowering effects. In order to make emodin play a better anti-obesity role, we designed and developed an emodin loaded dissolving microneedle patch, in which emodin existed in the form of emodin-polyvinylpyrrolidone co-precipitate (Emodin-PVP). Meanwhile, polydopamine (PDA) was added to the microneedle patch (PDA-Emodin-PVP-MN) for photothermal-enhanced chemotherapy of obesity. The average weight of the patch was 0.1 ± 0.05 g and the drug loading was 0.37 ± 0.031 mg. After 5 min of NIR irradiation (808 nm, 0.6 W/cm2), the rat abdominal temperature could reach 48 ℃, and the cumulative release of emodin reached 96.25%. The diffusion coefficient of emodin in the in vitro agar diffusion experiment was 249.27 mm2 h-1. No obvious toxicity was observed in hemolysis test, CCK-8 assay and microscopic histopathological analysis. The patch significantly reduced the percent of body weight ( P < 0.01), lipid-body ratio ( P < 0.001), serum FFAs ( P < 0.01) and the cell volume of peritesticular adipose tissue in the high-fat diet induced obese rats, indicating the patch had good anti-obesity effect. The mechanism of action may be related to the up-regulation of HSL and LPL protein levels in rat peritesticular adipose tissue.

Brown and Beige Adipose Tissue: One or Different Targets for Treatment of Obesity and Obesity-Related Metabolic Disorders?

The failure of the fight against obesity makes us turn to new goals in its treatment. Now, brown adipose tissue has attracted attention as a promising target for the treatment of obesity and associated metabolic disorders such as insulin resistance, dyslipidemia, and glucose tolerance disorders. Meanwhile, the expansion of our knowledge has led to awareness about two rather different subtypes: classic brown and beige (inducible brown) adipose tissue. These subtypes have different origin, differences in the expression of individual genes but also a lot in common. Both tissues are thermogenic, which means that, by increasing energy consumption, they can improve their balance with excess intake. Both tissues are activated in response to specific inducers (cold, beta-adrenergic receptor activation, certain food and drugs), but beige adipose tissue transdifferentiates back into white adipose tissue after the cessation of inducing action, while classic brown adipose tissue persists, but its activity decreases. In this review, we attempted to understand whether there are differences in the effects of different groups of thermogenesis-affecting drugs on these tissues. The analysis showed that this area of research is rather sparse and requires close attention in further studies.

Microneedles with Implantable Tip-Accumulated Therapeutics for the Long-Term Management of Psoriasis

Methotrexate is successfully used as the gold standard for managing moderate-to-severe psoriasis. However, the low bioavailability and short half-life of the oral pills and the invasiveness of the parenteral injections make these suboptimal therapeutic options. Microneedles, bridging the advantages of the former forms, are successfully used to deliver methotrexate for different therapeutic purposes. However, the utilized dissolving microneedles demand frequent administration, potentially compromising patients' compliance. Additionally, the high toxicity of methotrexate prompts a quest for safer alternatives. Phloretin, a natural compound with confirmed antipsoriatic potential, emerges as a promising candidate. Herein, microneedle patches with separable, slow-degrading tips are developed for the sustained delivery of methotrexate and phloretin, as a comprehensive solution for long-term psoriasis management. Both compounds are individually loaded at varying doses and display sustained-release profiles. The developed microneedle patches demonstrate high mechanical strength, favorable drug delivery efficiency, and remarkable antipsoriatic potential both in vitro in keratinocytes and in vivo in a psoriasis mouse model. Comparative analysis with two subcutaneous injections reveals a similar antipsoriatic efficacy with a single patch of either compound, with prominent phloretin safety. Therefore, the developed patches present a superior alternative to methotrexate's current marketed forms and provide a viable alternative (phloretin) with comparable antipsoriatic efficacy and higher safety.

Semaglutide alleviates gut microbiota dysbiosis induced by a high-fat diet

This study investigated the effects of semaglutide (Sema) on the gut microbiota of obese mice induced with high-fat diet (HFD). Male C57BL/6 J mice aged 6 weeks were enrolled and randomly distributed to four groups, which were provided with a normal control diet (NCD,NCD + Sema) and a 60% proportion of a high-fat diet (HFD,HFD + Sema), respectively. HFD was given for 10 weeks to develop an obesity model and the intervention was lasted for 18 days. The results showed semaglutide significantly reduced body weight gain, areas under the curve (AUC) of glucose tolerance test and insulin resistance test, as well as adipose tissue weight in mice. Semaglutide effectively reduced lipid deposition and lipid droplet formation in the liver of obese mice, and regulated the expression of genes related to abnormal blood glucose regulation. Additionally, semaglutide influenced the composition of gut microbiota, mitigating the microbial dysbiosis induced by a high-fat diet by impacting the diversity of the gut microbiota. After the high-fat diet intervention, certain strains such as Akkermansia, Faecalibaculum, and Allobaculum were significantly decreased, while Lachnospiraceae and Bacteroides were significantly increased. However, the application of semaglutide restored the lost flora and suppressed excessive bacterial abundance. Moreover, semaglutide increased the content of tight junction proteins and repaired the damage to intestinal barrier function caused by the high-fat diet intervention. Furthermore, correlation analysis revealed inverse relationship among Akkermansia levels and weight gain, blood glucose levels, and various obesity indicators. Correlation analysis also showed that Akkermansia level was negatively correlated with weight gain, blood glucose levels and a range of obesity indicators. This phenomenon may explain the anti-obesity effect of semaglutide, which is linked to alterations in gut microbiota, specifically an increase in the abundance of Akkermansia. In summary, our findings indicate that semaglutide has the potential to alleviate gut microbiota dysbiosis, and the gut microbiota may contribute to the obesity-related effects of this drug.

Recent advances in drug delivery systems based on natural and synthetic polymes for treating obesity

Obesity stands as a pervasive global public health issue, posing a formidable threat to human well-being as its prevalence continues to surge year by year. Presently, pharmacological treatment remains the favored adjunct strategy for addressing obesity. However, conventional delivery methods suffer from low bioavailability and the potential for side effects, underscoring the pressing need for more efficient and targeted delivery approaches. Recent research has delved extensively into emerging drug delivery systems employing polymers as carriers, with numerous preclinical studies contributing to the growing body of knowledge. This review concentrates on the utilization of natural polymers as drug delivery systems for the treatment of obesity, encompassing recent advancements in both natural and synthetic polymers. The comprehensive exploration includes an analysis of the advantages and disadvantages associated with these polymer carriers. The examination of these characteristics provides valuable insights into potential future developments in the field of drug delivery for obesity treatment.

Anti-obesity and metabolic benefits of metformin: Comparison of different delivery routes

Obesity is a severe public health problem. Healthy lifestyle interventions are commonly recommended for fighting obesity. But they are hard to follow and have low efficacy. Pharmacotherapy and surgery are of high efficacy but are beset with side effects. Browning subcutaneous white adipose tissue (WAT) is a practical and efficient approach for combating obesity. Metformin, a commonly used FDA-approved antidiabetic drug, is potent to induce browning of WAT through phosphorylation and activation of AMP-activated protein kinase. However, oral administration of metformin has low oral bioavailability, fast renal clearance, and low target specificity that limit metformin's application in browning WAT. Local and transdermal delivery of metformin directly to subcutaneous WAT using injection or microneedle (MN) in combination with iontophoresis (INT) may solve these problems. In this paper, we administered metformin to C57BL/6J obese mice using the following three routes: transdermal delivery (MN and INT), local injection into inguinal WAT (IgWAT, a type of subcutaneous WAT in mice), and oral gavage. The anti-obesity and metabolic effects of metformin via these delivery routes were determined and compared. As compared to local IgWAT injection and oral gavage delivery, transdermal delivery of metformin using MN and INT resulted in 9% lower body weight and 7% decrease in body fat% accompanied by improved energy metabolism and decreased inflammation through browning IgWAT in obese C57BL/6J mice. Transdermal delivery of metformin using MN and INT is an effective approach in browning subcutaneous WAT for combating obesity and improving metabolic health.

Wearable Sensor Patch with Hydrogel Microneedles for In Situ Analysis of Interstitial Fluid

Continuous real-time monitoring of biomarkers in interstitial fluid is essential for tracking metabolic changes and facilitating the early detection and management of chronic diseases such as diabetes. However, developing minimally invasive sensors for the in situ analysis of interstitial fluid and addressing signal delays remain a challenge. Here, we introduce a wearable sensor patch incorporating hydrogel microneedles for rapid, minimally invasive collection of interstitial fluid from the skin while simultaneously measuring biomarker levels in situ. The sensor patch is stretchable to accommodate the swelling of the hydrogel microneedles upon extracting interstitial fluid and adapts to skin deformation during measurements, ensuring consistent sensing performance in detecting model biomarker concentrations, such as glucose and lactate, in a mouse model. The sensor patch exhibits in vitro sensitivities of 0.024 ± 0.002 μA mM-1 for glucose and 0.0030 ± 0.0004 μA mM-1 for lactate, with corresponding linear ranges of 0.1-3 and 0.1-12 mM, respectively. For in vivo glucose sensing, the sensor patch demonstrates a sensitivity of 0.020 ± 0.001 μA mM-1 and a detection range of 1-8 mM. By integrating a predictive model, the sensor patch can analyze and compensate for signal delays, improving calibration reliability and providing guidance for potential optimization in sensing performance. The sensor patch is expected to serve as a minimally invasive platform for the in situ analysis of multiple biomarkers in interstitial fluid, offering a promising solution for continuous health monitoring and disease management.

Anti-Obesity Drug Delivery Systems: Recent Progress and Challenges

Obesity has reached an epidemic proportion in the last thirty years, and it is recognized as a major health issue in modern society now with the possibility of serious social and economic consequences. By the year 2030, nearly 60% of the global population may be obese or overweight, which emphasizes a need for novel obesity treatments. Various traditional approaches, such as pharmacotherapy and bariatric surgery, have been utilized in clinical settings to treat obesity. However, these methods frequently show the possibility of side effects while remaining ineffective. There is, therefore, an urgent need for alternative obesity treatments with improved efficacy and specificity. Polymeric materials and chemical strategies are employed in emerging drug delivery systems (DDSs) to enhance therapy effectiveness and specificity by stabilizing and controlling the release of active molecules such as natural ingredients. Designing DDSs is currently a top priority research objective with an eye towards creating obesity treatment approaches. In reality, the most recent trends in the literature demonstrate that there are not enough in-depth reviews that emphasize the current knowledge based on the creation and design of DDSs for obesity treatment. It is also observed in the existing literature that a complex interplay of different physical and chemical parameters must be considered carefully to determine the effectiveness of the DDSs, including microneedles, for obesity treatment. Additionally, it is observed that these properties depend on how the DDS is synthesized. Although many studies are at the animal-study stage, the use of more advanced DDS techniques would significantly enhance the development of safe and efficient treatment approaches for obese people in the future. Considering these, this review provides an overview of the current anti-obesity treatment approaches as well as the conventional anti-obesity therapeutics. The article aims to conduct an in-depth discussion on the current trends in obesity treatment approaches. Filling in this knowledge gap will lead to a greater understanding of the safest ways to manage obesity.

Progress in the preparation and evaluation of glucose-sensitive microneedle systems and their blood glucose regulation

Glucose-sensitive microneedle systems (GSMSs) as an intelligent strategy for treating diabetes can well solve the problems of puncture pain, hypoglycemia, skin damage, and complications caused by the subcutaneous injection of insulin. According to the various functions of each component, herein, therapeutic GSMSs are reviewed based on three parts (glucose-sensitive models, diabetes medications, and microneedle body). Moreover, the characteristics, benefits, and drawbacks of three types of typical glucose-sensitive models (phenylboronic acid based polymer, glucose oxidase, and concanavalin A) and their drug delivery models are reviewed. In particular, phenylboronic acid-based GSMSs can provide a long-acting drug dose and controlled release rate for the treatment of diabetes. Moreover, their painless, minimally invasive puncture also greatly improves patient compliance, treatment safety, and potential application prospects.

The use of cellulose, chitosan and hyaluronic acid in transdermal therapeutic management of obesity: A review

Obesity is a clinical condition with rising popularity and detrimental impacts on human health. According to the World Health Organization, obesity is the sixth most common cause of death worldwide. It is challenging to combat obesity because medications that are successful in the clinical investigation have harmful side effects when administered orally. The conventional approaches for treating obesity primarily entail synthetic compounds and surgical techniques but possess severe adverse effects and recurrences. As a result, a safe and effective strategy to combat obesity must be initiated. Recent studies have shown that biological macromolecules of the carbohydrate class, such as cellulose, hyaluronic acid, and chitosan, can enhance the release and efficacy of medications for obesity but due to their short biological half-lives and poor oral bioavailability, their distribution rate is affected. This helps to comprehend the need for an effective therapeutic approach via a transdermal drug delivery system. This review focuses on the transdermal administration, utilizing cellulose, chitosan, and hyaluronic acid via microneedles, as it offers a promising solution to overcome existing therapy limitations in managing obesity and it also highlights how microneedles can effectively deliver therapeutic substances through the skin's outer layer, bypassing pain receptors and specifically targeting adipose tissue.

Flexible Monitoring, Diagnosis, and Therapy by Microneedles with Versatile Materials and Devices toward Multifunction Scope

Microneedles (MNs) have drawn rising attention owing to their merits of convenience, noninvasiveness, flexible applicability, painless microchannels with boosted metabolism, and precisely tailored multifunction control. MNs can be modified to serve as novel transdermal drug delivery, which conventionally confront with the penetration barrier caused by skin stratum corneum. The micrometer-sized needles create channels through stratum corneum, enabling efficient drug delivery to the dermis for gratifying efficacy. Then, incorporating photosensitizer or photothermal agents into MNs can conduct photodynamic or photothermal therapy, respectively. Besides, health monitoring and medical detection by MN sensors can extract information from skin interstitial fluid and other biochemical/electronic signals. Here, this review discloses a novel monitoring, diagnostic, and therapeutic pattern by MNs, with elaborate discussion about the classified formation of MNs together with various applications and inherent mechanism. Hereby, multifunction development and outlook from biomedical/nanotechnology/photoelectric/devices/informatics to multidisciplinary applications are provided. Programmable intelligent MNs enable logic encoding of diverse monitoring and treatment pathways to extract signals, optimize the therapy efficacy, real-time monitoring, remote control, and drug screening, and take instant treatment.

Recent advances in polymer microneedles for drug transdermal delivery: Design strategies and applications

In recent years, the transdermal drug delivery based on microneedles (MNs) technology has received extensive attention, which offers a safer and painless alternative to hypodermic needle injection. They can pierce the stratum corneum and deliver drugs to the epidermis and dermis-structures of skin, showing prominent properties such as minimally invasive, bypassing first-pass metabolism, and self-administered. A range of materials have been used to fabricate MNs, such as silicon, metal, glass, and polymers. Among them, polymer MNs have gained increasing attention from pharmaceutical and cosmetic companies as one of the promising drug delivery methods. Microneedle products have recently become available on the market, and some of them are under evaluation for efficacy and safety. This paper focuses on current state of polymer MNs in the drug transdermal delivery. The materials and methods for the fabrication of polymer MNs and their drug administration are described. The recent progresses of polymer MNs for treatment of cancer, vaccine delivery, blood glucose regulation, androgenetic alopecia, obesity, tissue healing, myocardial infarction and gout are reviewed. The challenges of MNs technology are summarized and the future development trend of MNs is also prospected. This article is protected by copyright. All rights reserved.

Transdermal Drug Delivery Systems and Their Use in Obesity Treatment

Transdermal drug delivery (TDD) has recently emerged as an effective alternative to oral and injection administration because of its less invasiveness, low rejection rate, and excellent ease of administration. TDD has made an important contribution to medical practice such as diabetes, hemorrhoids, arthritis, migraine, and schizophrenia treatment, but has yet to fully achieve its potential in the treatment of obesity. Obesity has reached epidemic proportions globally and posed a significant threat to human health. Various approaches, including oral and injection administration have widely been used in clinical setting for obesity treatment. However, these traditional options remain ineffective and inconvenient, and carry risks of adverse effects. Therefore, alternative and advanced drug delivery strategies with higher efficacy and less toxicity such as TDD are urgently required for obesity treatment. This review summarizes current TDD technology, and the main anti-obesity drug delivery system. This review also provides insights into various anti-obesity drugs under study with a focus on the recent developments of TDD system for enhanced anti-obesity drug delivery. Although most of presented studies stay in animal stage, the application of TDD in anti-obesity drugs would have a significant impact on bringing safe and effective therapies to obese patients in the future.