Transdermal delivery of Chinese herbal medicine extract using dissolvable microneedles for hypertrophic scar treatment

Transdermal anti-inflammatory effects and mechanisms of hydrogel patches containing seco-iridoids from Gentiana macrophylla Pall

Gentiana macrophylla Pall. (GMP), known as "Qinjiao" in the Chinese Pharmacopeia, has a long history of clinical application in treating rheumatoid arthritis, primarily due to its iridoid components. However, the transdermal anti-inflammatory efficacy, active ingredients, and underlying mechanisms of these components remain under-investigated. This study aimed to clarify the transdermal anti-inflammatory effects and mechanisms of seco-iridoids from GMP by establishing a hydrogel patch transdermal drug delivery system. Using crude and refined GMP iridoid extracts as active components, the hydrogel patch system was established based on physicochemical properties, skin irritation tests, in vitro drug release, and skin permeation. The anti-inflammatory efficacy of these iridoid hydrogel patches was assessed using a carrageenan-induced paw edema model in mice. Content analysis and skin permeation studies identified gentiopicroside (GPS) and swertiamarin (SWE) as the key bioactive constituents. The hydrogel patch system demonstrated superior skin permeation and sustained drug release profiles compared to oral administration, addressing issues of poor bioavailability and rapid metabolism. Mechanistic studies revealed that these seco-iridoids exert their anti-inflammatory effects primarily through modulation of the iNOS/COX-2/NF-κB signaling cascade. Pharmacokinetic evaluations showed significant improvements in bioavailability and prolonged drug release, highlighting the clinical advantages of the transdermal approach. This work lays a solid foundation for the further optimization and clinical translation of GMP-based transdermal formulations, providing a framework for the investigation of iridoid transdermal systems and their therapeutic applications in inflammatory conditions.

Microneedle-Enabled Breakthroughs in Nucleic Acid Therapeutics

Nucleic acid therapy demonstrates great potential in cancer treatment, infectious disease prevention, and vaccine development due to its advantages, such as rapid production, long-lasting effects, and high target specificity. Although nucleic acid therapy is considered ideal for the development of novel therapeutic strategies, its clinical application still faces numerous challenges, including the lack of efficient delivery systems, insufficient drug formulation stability, and the limitations imposed by the skin barrier on drug dosage delivery. Microneedles, as an innovative transdermal drug delivery technology, can penetrate the stratum corneum and directly access the skin's microcirculation, enabling the efficient delivery of genes and drugs. This technology offers several advantages, such as ease of operation, minimally invasive and painless application, and high safety. Combining microneedle technology with nucleic acid therapy fully leverages the strengths of both approaches, significantly enhancing therapeutic efficacy and bioavailability while maximizing treatment potential. This review explores the application prospects and advantages of combining microneedle delivery systems with nucleic acid therapy.

Ultrasound-assisted preparation of shikonin-loaded emulsions for the treatment of bacterial infections

Bacteria can encapsulate themselves in a self-generated matrix of hydrated extracellular polymeric substances such as polysaccharides, proteins, and nucleic acids, thereby forming bacterial biofilm infections. These biofilms are drug resistant and will diminish the efficacy of antimicrobial agents, rendering treatment of such infections challenging. Herein, an innovative strategy is proposed to synergistically degrade bacterial biofilms and eradicate the entrapped bacteria through integrating α-amylase (α-Amy), shikonin (SK) and epigallocatechin gallate (EGCG) within an emulsion. The natural protein α-Amy is deployed to enzymatically hydrolyze the polysaccharide of biofilms. Due to the amphipilic properties of α-Amy and the cross-linking capability of EGCG, the formed α-Amy/SK@EGCG emulsion possess high stability. SK was encapsulated within the emulsion through ultrasound-assisted assembly, targeting to treat bacterial infection after biofilm degradation. In vitro and in vivo experiments demonstrate that the polyphenol-protein stabilized emulsion loaded with antibacterial SK achieves profound penetration into the biofilms due to the extracellular polysaccharide hydrolysis mediated by α-Amy. As a result, the α-Amy/SK@EGCG emulsion can significantly alleviate inflammation symptoms and accelerate the healing process of biofilm-infected wounds. This study provides a promising therapeutic strategy for the development of novel materials aimed for the enhanced treatment of bacterial biofilm infections.

Paper battery powered iontophoresis microneedles patch for hypertrophic scar treatment

Hypertrophic scar (HS) is a plaque fibrous and indurated dermal lesion that may cause physical, psychological, and cosmetic challenges for patients. Intralesional injection of triamcinolone acetonide (TA) is commonly used in clinical practice, which cause unbearable pain and uneven drug delivery within HS tissue. Herein, we developed a paper battery powered iontophoresis-driven microneedles patch (PBIMNP) for self-management of HS. The high integration of PBIMNP was achieved by incorporating a paper battery as the power source for iontophoresis. The transdermal drug delivery strategy of PBIMNP combined microneedles and iontophoresis techniques, involving "pressing and poking, phase transformation, and diffusion and iontophoresis", which can actively deliver 90.19% drug into the HS tissue with excellent in vitro drug permeation performance. PBIMNP administration effectively reduced the mRNA and protein levels, leading to a decrease in the expression of TGF-β1 and Col I associated with HS formation, demonstrating its efficacy in HS treatment. The microneedles and wearable design endow the PBIMNP as a highly promising platform for self-administration on HS treatment.

Dual-strategy microneedles of bio‑oxygen therapy and artificial enzyme anti-oxidation for psoriasis treatment

Oxidative stress results from an imbalance between the production of free radicals by oxidants and their removal by antioxidants. Chronic oxidative stress is a key factor in inflammation, characterized by hypoxic microenvironments and elevated levels of reactive oxygen species (ROS). Psoriasis, a common chronic inflammatory skin disorder, profoundly impacts the physical and psychological well-being of affected individuals. In response to this, we have innovatively developed a core-shell structured Chlorella-Prussian Blue Complex (Z-PB), integrating dual therapeutic strategies of biological oxygen therapy and oxidative stress regulation to address psoriasis. The Z-PB leveraged the unique ability of Chlorella to generate dissolved oxygen under light, combined with the broad enzymatic activity of Prussian Blue (PB), to effectively ameliorate the oxidative stress in the chronic inflammatory microenvironment. Additionally, the Z-PB overcame challenges such as the survival of Chlorella in high ROS environments and the aggregation of nanoenzymes. The Z-PB-loaded hyaluronic acid microneedles (Z-PBHA/MNs) demonstrated excellent skin permeability, in vitro release profiles, and biocompatibility. These Z-PBHA/MNs had been shown to alleviate psoriasis induced by imiquimod (IMQ). Overall, the Z-PBHA/MNs incorporating both biological oxygen therapy and artificial enzyme antioxidants represented a promising and innovative therapeutic strategy for the treatment of psoriasis.

A strategy for selective screening of dual-target bioactive compounds against hypertrophic scar through inhibiting angiotensin II type 1 receptor while stimulating type 2 receptor from Chinese herbs

BACKGROUND

Cutaneous hypertrophic scar is a fibro-proliferative hard-curing disease. Recent studies have proved that antagonists of angiotensin II type 1 receptor (AT1R) and agonists of type 2 receptor (AT2R) were able to relieve hypertrophic scar. Therefore, establishing new methods to pursue dual-target lead compounds from Chinese herbs is in much demand for treating scar.

METHODS

To this end, we immobilized AT1R or AT2R onto the surface of silica gel from cell lysates through a specific covalent bond by bioorthogonal chemistry. The columns containing immobilized AT1R or AT2R were jointly utilized to pursue potential bioactive compounds simultaneously binding to AT1R and AT2R from the extract of Rhei Radix et Rhizoma. Their functions on AT1R and AT2R expressions were investigated by in vitro and in vivo experiments.

RESULTS

Aloe-emodin and emodin were identified as the potential bioactive compounds binding to both of the two receptors, thereby improving the appearance and pathomorphology of hypertrophic scar. They blocked the AT1R pathway to down-regulate the expression of transforming growth factor-β1 (TGF-β1) and stimulate matrix metalloproteinase-1 (MMP-1) expression. As such, the expression of collagen I/III reduced. Conversely, the bindings of the two compounds to AT2R reduced the production of nuclear factor-кB1 (NF-кB1), whereby the generation of interleukin-6 (IL-6) was blocked.

CONCLUSION

We reasoned that aloe-emodin and emodin had the potential to become dual-target candidates against hypertrophic scar through the regulation of AT1R and AT2R signaling pathways. It showed considerable potential to become a universal strategy for pursuing multi-target bioactive compounds from Chinese herbs by the utilization of diverse immobilized receptors in a desired order.

Leveraging Microneedles for Raised Scar Management

Disruption of the molecular pathways during physiological wound healing can lead to raised scar formation, characterized by rigid, thick scar tissue with associated symptoms of pain and pruritus. A key mechanical factor in raised scar development is excessive tension at the wound site. Recently, microneedles (MNs) have emerged as promising tools for scar management as they engage with scar tissue and provide them with mechanical off-loading from both internal and external sources. This review explores the mechanisms by which physical intervention of drug-free MNs alleviates mechanical tension on fibroblasts within scar tissue, thereby promoting tissue remodeling and reducing scar severity. Additionally, the role of MNs as an efficient cargo delivery system for the controlled and sustained release of a wide range of therapeutic agents into scar tissue is highlighted. By penetrating scar tissue, MNs facilitate controlled and sustained localized drug administration to modulate inflammation and fibroblastic cell growth. Finally, the remaining challenges and the future perspective of the field have been highlighted.

Single-dose of integrated bilayer microneedles for enhanced hypertrophic scar therapy with rapid anti-inflammatory and sustained inhibition of myofibroblasts

Hypertrophic scar (HS) tends to raised above skin level with high inflammatory microenvironment and excessive proliferation of myofibroblasts. The HS therapy remains challenging due to dense scar tissue which makes it hard to penetrate, and the side effects resulting from intralesional corticosteroid injection which is the mainstay treatment in clinic. Herein, bilayer microneedle patches combined with dexamethasone and colchicine (DC-MNs) with differential dual-release pattern is designed. Two drugs loaded in commercially available materials HA and PLGA, respectively. Specifically, after administration, outer layer rapidly releases the anti-inflammatory drug dexamethasone, which inhibits macrophage polarization to pro-inflammatory phenotype in scar tissue. Subsequently, inner layer degrades sustainedly, releasing antimicrotubular agent colchicine, which suppresses the overproliferation of myofibroblasts with extremely narrow therapeutic window, and inhibits the overexpression of collagen, as well as promotes the regular arrangement of collagen. Only applied once, DC-MNs directly delivered drugs to the scar tissue. Compared to traditional treatment regimen, DC-MNs significantly suppressed HS at lower dosage and frequency by differential dual-release design. Therefore, this study put forward the idea of integrated DC-MNs accompany the development of HS, providing a non-invasive, self-applicable, more efficient and secure strategy for treatment of HS.

Dissolving microneedle patch loaded with adipokines-enriched adipose extract relieves atopic dermatitis in mouse via modulating immune disorders, microbiota imbalance, and skin barrier defects

Atopic dermatitis (AD) is a chronic relapsing dermatosis that demands new therapies. This research group previously developed a physically extracted adipose-derived extracellular matrix named adipose collagen fragments (ACF), which was determined containing massive adipose matrix-bound adipokines and medicable on AD through intradermal injection. However, problems concerning the control of drug release and inevitable pain caused by injection hinder the application of ACF in clinics. Microneedle (MN) is a rapid developing technique for precise and painless transdermal drug delivery. Therefore, a dissolving methacrylated gelatin/hyaluronic acid MN patch loaded with ACF was developed in this study. The morphological characteristics, mechanical properties, penetration ability, as well as biocompatibility and degradation efficiency of ACF-MN were evaluated, and its efficacy on ovalbumin-induced AD mice was also investigated. ACF-MN exhibited excellent penetration ability, biocompatibility, degradation efficiency, and satisfying efficacy on murine AD similar with fresh-made ACF. Furthermore, RNA-Seq combining bioinformatics were performed for mechanism exploration. ACF treatment showed a comprehensive efficacy on AD via restoring inflammatory dysregulation, microbiota imbalance, and skin barrier defects. This study offered a novel MN-based ACF-bound adipokines transdermal delivery system that may serve as a promising strategy for relieving AD.

Hispidulin-rich fraction of Clerodendrum fragrans Wild. (Sesewanua) dissolving microneedle as antithrombosis candidate: A proof of concept study

Existing conventional antithrombosis drugs have caused many side effects, opening up opportunities for the development of new thrombotic drugs. There is potential to use the hispidulin-rich fraction of sesewanua (HRFS) as a new antithrombotic. The oral route limitation of hispidulin, as a low water solubility and non-polar compound, can be addressed. This study explores the potential of HRFS in the form of dissolving microneedles (DMN). The formula was created using polymers such as polyvinyl alcohol (PVA), polyvinyl pyrrolidone K-30 (PVP), and non-ionic surfactant. Ex vivo permeation studies found that 184.95 µg/cm2 of hispidulin was released 60 h after the best formulation. After 14 days of applying HRFS-DMN, the anticoagulant and antioxidant activity in male albino rats showed higher Activated Partial Thromboplastin Time (aPTT) and Prothrombin Time (PT) values and lower Inter Cellular Adhesion Molecule-1 (ICAM-1) values. No statistically significant differences were found between the effects of two and four HRFS-DMN and the injection of heparin at a dosage of 200 IU per kilogram. However, notable distinctions were observed when comparing HRFS-DMN to negative controls, oral and quercetin as positive controls at anti-ICAM activity. The findings confirmed the feasibility of HRFS-DMN for thrombosis and its effectiveness in delivering Hispidulin (HIS) into the bloodstream. This DMN is non-irritating, safe, and painless, showing promising outcomes in enhancing the efficacy of thrombosis treatment via the transdermal route.

Research Progress on Chitosan Microneedle Arrays in Transdermal Drug Delivery

As a type of transdermal drug delivery system (TDDS), Microneedles (MNs) have garnered significant attention from researchers due to their ability to penetrate the stratum corneum (SC) of the skin, enhance drug permeability and bioavailability, avoid first-pass metabolism, and cause minimal damage to the skin. This makes them particularly suitable for localized transdermal drug delivery. Dissolvable microneedles (DMNs) can encapsulate sensitive particles, provide high drug-loading capacity, and possess biodegradability and biocompatibility, attracting extensive research interest. Chitosan (CS) has been selected as the matrix for manufacturing DMNs due to its excellent properties, including not eliciting an immune response in vivo and having active functional groups such as hydroxyl and amino groups that allow for modifications to impart appropriate mechanical strength and functionality to DMNs for specific applications. This paper provides a comprehensive review of the research status of various chitosan-based microneedles (CSMNs), explores the mechanisms of their dissolution in vivo, and discusses their applications in promoting wound healing, delivering macromolecular drugs, vaccine delivery, and anti-tumor therapies.

Microneedles as an Emerging Platform for Transdermal Delivery of Phytochemicals

Phytochemicals, which are predominantly found in plants, hold substantial medicinal value. Despite their potential, challenges such as poor oral bioavailability and instability in the gastrointestinal tract have limited their therapeutic use. Traditional intra/transdermal drug delivery systems offer some advantages over oral administration but still suffer from issues such as limited penetration depth, slow drug release rates, and inconsistent drug absorption. In contrast, microneedles (MNs) represent a significant advancement in intra/transdermal drug delivery by providing precise control over phytochemical delivery and enhanced penetration capabilities. By circumventing skin barriers, MNs directly access dermal layers rich in blood vessels and lymphatics, thus facilitating efficient phytochemical delivery. This review extensively discusses the obstacles of traditional oral delivery and the benefits of intra/transdermal delivery routes with a particular focus on the transformative potential of MNs for phytochemical delivery. This review explores the complexities of delivering phytochemicals through intra/transdermal routes, the development and types of MNs as innovative delivery tools, and the optimal design and properties of MNs for effective phytochemical delivery. Additionally, this review examines the versatile applications of MN-mediated phytochemical delivery, including its role in administering phytophotosensitizers for photodynamic therapy, and concludes with insights into relevant patents and future perspectives.

Antioxidative hydrogel based on hyaluronic acid/polyethylene glycol loaded with shikonin-coated flexible liposome and evaluation of its therapeutic effect on eczema

Eczema, a common skin condition, is gaining attention due to its increasing annual prevalence and severe influence on both bodily and mental health. Existing treatments for this disease often have significant side effects and safety concerns. Comfrey, a traditional Chinese herbal remedy, is commonly used to treat skin conditions. Shikonin, the primary active compound in comfrey, has demonstrated efficacy in treating eczema. Herein, a flexible liposome-containing SHI was dispersed in hydrogels based on hyaluronic acid (HA) and polyethylene glycol(PEG) for the treatment of eczema. The hydrogel performed well in delaying drug release. SHI-F-Gel demonstrated notable antioxidant properties, effectively eliminating over 80 % of free radicals. Compared to the SHI solution, SHI-F-Gel significantly increased drug skin retention by 312.9 %. In animal studies, SHI-F-Gel administration reduced epidermal thickness in the affected area by approximately 36.8 % and increased collagen deposition by 90.23 %. Additionally, SHI-F-Gel inhibited the expression of pro-inflammatory cytokines interleukin-4 (IL-4) and IL-17. This observed reduction in inflammation suggests that the treatment is effective. In conclusion, the flexible SHI-based liposome hydrogel demonstrates excellent adhesion and biocompatibility, making it a promising candidate for enhancing eczema treatment.

Emerging biomedical technologies for scarless wound healing

Complete wound healing without scar formation has attracted increasing attention, prompting the development of various strategies to address this challenge. In clinical settings, there is a growing preference for emerging biomedical technologies that effectively manage fibrosis following skin injury, as they provide high efficacy, cost-effectiveness, and minimal side effects compared to invasive and costly surgical techniques. This review gives an overview of the latest developments in advanced biomedical technologies for scarless wound management. We first introduce the wound healing process and key mechanisms involved in scar formation. Subsequently, we explore common strategies for wound treatment, including their fabrication methods, superior performance and the latest research developments in this field. We then shift our focus to emerging biomedical technologies for scarless wound healing, detailing the mechanism of action, unique properties, and advanced practical applications of various biomedical technology-based therapies, such as cell therapy, drug therapy, biomaterial therapy, and synergistic therapy. Finally, we critically assess the shortcomings and potential applications of these biomedical technologies and therapeutic methods in the realm of scar treatment.

Promising strategies for smart insulin delivery system: Glucose-sensitive microneedle

The diabetes treatment landscape is rapidly evolving towards intelligent and precise therapeutic interventions. Among these advancements, glucose-sensitive microneedle patches (GSMPs), which can automatically adjust the transdermal release rate of insulin based on glucose concentrations, are emerging as a promising strategy. In this work, a new classification method has been proposed for GSMPs, categorizing them into integrated, all-in-one, and core-shell structures. The working mechanism and performance of GSMPs are thoroughly analyzed to compare the advantages and disadvantages of these three forms. The correlation between glucose-sensitive performance and normal blood glucose maintenance time (NGT) is further explored. Our findings indicate that all-in-one GSMPs demonstrate a positive correlation between in vitro glucose-sensitive controlled-release performance and NGT, unlike assembled GSMPs, where the performance is influenced by the matrix material and crosslinking factors. Simultaneously, challenges in clinical translation and future development trends are discussed from a patient's perspective. In summary, the new classification method, in-depth explanation of mechanisms, and analysis of challenges in this work contribute to a better understanding of the field of GSMPs and provide guidance for the development of more advanced and efficient GSMPs.

Fabrication of Hybrid Coated Microneedles with Donepezil Utilizing Digital Light Processing and Semisolid Extrusion Printing for the Management of Alzheimer's Disease

Microneedle (MN) patches are gaining increasing attention as a cost-effective technology for delivering drugs directly into the skin. In the present study, two different 3D printing processes were utilized to produce coated MNs, namely, digital light processing (DLP) and semisolid extrusion (SSE). Donepezil (DN), a cholinesterase inhibitor administered for the treatment of Alzheimer's disease, was incorporated into the coating material. Physiochemical characterization of the coated MNs confirmed the successful incorporation of donepezil as well as the stability and suitability of the materials for transdermal delivery. Optical microscopy and SEM studies validated the uniform weight distribution and precise dimensions of the MN arrays, while mechanical testing ensured the MNs' robustness, ensuring efficient skin penetration. In vitro studies were conducted to evaluate the produced transdermal patches, indicating their potential use in clinical treatment. Permeation studies revealed a significant increase in DN permeation compared to plain coating material, affirming the effectiveness of the MNs in enhancing transdermal drug delivery. Confocal laser scanning microscopy (CLSM) elucidated the distribution of the API, within skin layers, demonstrating sustained drug release and transcellular transport pathways. Finally, cell studies were also conducted on NIH3T3 fibroblasts to evaluate the biocompatibility and safety of the printed objects for transdermal applications.

A flexible and dissolving traditional Chinese medicine microneedle patch for sleep-aid intervention

About a quarter of the world's population suffers from insomnia, and the number of the insomniacs is gradually increasing. However, the current drug therapy and non-drug therapy sleep-aid methods have certain limitations. In general, the sleep-aid effect of drug therapy is better than that of Non-drug therapy, but western medicine may lead to some side effects and drug abuse. Although the side effects of Chinese Herbal Medicine (CHM) are relatively small, making the herbal decoction is complex and time-consuming. Therefore, exploring a novel sleep-aid method is very significant. In this paper, a flexible and dissolving Traditional Chinese Medicine (TCM) microneedle patch is proposed for sleep-aid intervention. The TCM microneedle patch is a micrometer-scale intrusive object, and the herbal extracts are carried by the patch. The materials, design method, and fabrication process of the microneedle patch have been described in detail. Besides, the mechanical characteristics of the microneedle patch, sleep-aid effect evaluation method, and experimental scheme have been presented. Three microneedle tips with radii of 5 μm, 15 μm, and 22 μm are selected for simulation analysis. Abaqus simulation results indicate that the smaller the radius of the microneedle tip, the smaller the piercing force. Considering that the microneedle should easily penetrate the skin without buckling, that is, the piercing force should be larger than the buckling force, thus 15 μm, instead of 5 μm or 22 μm, is more suitable to be adopted as the radius of the microneedle tip. For the microneedle with the radius of 15 μm, the piercing force is 0.033 N, and the difference between the piercing force and buckling force is 0.036 N. Experimental results demonstrate that the fracture force of the microneedle is about 0.29 N, which is far larger than the piercing force and buckling force. The single-lead EEG signals of the frontal lobe are used to evaluate the sleep-aid effect of the TCM microneedle patch. After sleep-aid intervention on the Anmian and Yintang acupoints using the patches, for most subjects, the ratios of the low-frequency brain wave energies to the high-frequency brain wave energies are increased obviously, indicating that the proposed sleep-aid method is effective.

Baroreceptor-Inspired Microneedle Skin Patch for Pressure-Controlled Drug Release

Objective: We have developed a baroreceptor-inspired microneedle skin patch for pressure-controlled drug release. Impact Statement: This design is inspired by the skin baroreceptors, which are mechanosensitive elements of the peripheral nervous system. We adopt the finger touching to trigger the electric stimulation, ensuring a fast-response and user-friendly administration with potentially minimal off-target effects. Introduction: Chronic skin diseases bring about large, recurrent skin damage and often require convenient and timely transdermal treatment. Traditional methods lack spatiotemporal controllable dosage, leaving a risk of skin irritation or drug resistance issues. Methods: The patch consists of drug-containing microneedles and stretchable electrode array. The electrode array, integrated with the piezoconductive switch and flexible battery, provides a mild electric current only at the spot that is pressed. Drugs in microneedles will then flow along the current into the skin tissues. The stretchable feature also provides the mechanical robustness and electric stability of the device on large skin area. Results: This device delivers Cy3 dye in pig skin with spatiotemporally controlled dosage, showing ~8 times higher fluorescence intensity than the passive delivery. We also deliver insulin and observe the reduction of the blood glucose level in the mouse model upon pressing. Compared with passive delivery without pressing, the dosage of drugs released by the simulation is 2.83 times higher. Conclusion: This baroreceptor-inspired microneedle skin patch acts as a good example of the biomimicking microneedle device in the precise control of the drug release profile at the spatiotemporal resolution.

Rapid formed temperature-sensitive hydrogel for the multi-effective wound healing of deep second-degree burn with shikonin based scar prevention

Burns are a significant public health issue worldwide, resulting in prolonged hospitalization, disfigurement, disability and, in severe cases, death. Among them, deep second-degree burns are often accompanied by bacterial infections, insufficient blood flow, excessive skin fibroblasts proliferation and collagen deposition, all of which contribute to poor wound healing and scarring following recovery. In this study, SNP/MCNs-SKN-chitosan-β-glycerophosphate hydrogel (MSSH), a hydrogel composed of a temperature-sensitive chitosan-β-glycerophosphate hydrogel matrix (CGH), mesoporous carbon nanospheres (MCNs), nitric oxide (NO) donor sodium nitroprusside (SNP) and anti-scarring substance shikonin (SKN), is intended for use as a biomedical material. In vitro tests have revealed that MSSH has broad-spectrum antibacterial abilities and releases NO in response to near-infrared (NIR) laser to promote angiogenesis. Notably, MSSH can inhibit excessive proliferation of fibroblasts and effectively reduce scarring caused by deep second-degree burns, as demonstrated by in vitro and in vivo tests.

Microneedles Based on a Biodegradable Polymer-Hyaluronic Acid

Transdermal transport can be challenging due to the difficulty in diffusing active substances through the outermost layer of the epidermis, as the primary function of the skin is to protect against the entry of exogenous compounds into the body. In addition, penetration of the epidermis for substances hydrophilic in nature and particles larger than 500 Da is highly limited due to the physiological properties and non-polar nature of its outermost layer, namely the stratum corneum. A solution to this problem can be the use of microneedles, which "bypass" the problematic epidermal layer by dispensing the active substance directly into the deeper layers of the skin. Microneedles can be obtained with various materials and come in different types. Of special interest are carriers based on biodegradable and biocompatible polymers, such as polysaccharides. Therefore, this paper reviews the latest literature on methods to obtain hyaluronic acid-based microneedles. It focuses on the current advancements in this field and consequently provides an opportunity to guide future research in this area.

Preparation of Compound Salvia miltiorrhiza-Blumea balsamifera Nanoemulsion Gel and Its Effect on Hypertrophic Scars in the Rabbit Ear Model

Hypertrophic scars (HS) still remain an urgent challenge in the medical community. Traditional Chinese medicine (TCM) has unique advantages in the treatment of HS. However, due to the natural barrier of the skin, it is difficult for the natural active components of TCM to more effectively penetrate the skin and exert therapeutic effects. Therefore, the development of an efficient drug delivery system to facilitate enhanced transdermal absorption of TCM becomes imperative for its clinical application. In this study, we designed a compound Salvia miltiorrhiza-Blumea balsamifera nanoemulsion gel (CSB-NEG) and investigated its therapeutic effects on rabbit HS models. The prescription of CSB-NEG was optimized by single-factor, pseudoternary phase diagram, and central composite design experiments. The results showed that the average particle size and PDI of the optimized CSB-NE were 46.0 ± 0.2 nm and 0.222 ± 0.004, respectively, and the encapsulation efficiency of total phenolic acid was 93.37 ± 2.56%. CSB-NEG demonstrated excellent stability and skin permeation in vitro and displayed a significantly enhanced ability to inhibit scar formation compared to the CSB physical mixture in vivo. After 3 weeks of CSB-NEG treatment, the scar appeared to be flat, pink, and flexible. Furthermore, this treatment also resulted in a decrease in the levels of the collagen I/III ratio and TGF-β1 and Smad2 proteins while simultaneously promoting the growth and remodeling of microvessels. These findings suggest that CSB-NEG has the potential to effectively address the barrier properties of the skin and provide therapeutic benefits for HS, offering a new perspective for the prevention and treatment of HS.

Targeting Diverse Wounds and Scars: Recent Innovative Bio-design of Microneedle Patch for Comprehensive Management

Wounds and the subsequent formation of scars constitute a unified and complex phased process. Effective treatment is crucial; however, the diverse therapeutic approaches for different wounds and scars, as well as varying treatment needs at different stages, present significant challenges in selecting appropriate interventions. Microneedle patch (MNP), as a novel minimally invasive transdermal drug delivery system, has the potential for integrated and programmed treatment of various diseases and has shown promising applications in different types of wounds and scars. In this comprehensive review, the latest applications and biotechnological innovations of MNPs in these fields are thoroughly explored, summarizing their powerful abilities to accelerate healing, inhibit scar formation, and manage related symptoms. Moreover, potential applications in various scenarios are discussed. Additionally, the side effects, manufacturing processes, and material selection to explore the clinical translational potential are investigated. This groundwork can provide a theoretical basis and serve as a catalyst for future innovations in the pursuit of favorable therapeutic options for skin tissue regeneration.

Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Nano-formulated delivery of active ingredients from traditional Chinese herbal medicines for cancer immunotherapy

Cancer immunotherapy has garnered promise in tumor progression, invasion, and metastasis through establishing durable and memorable immunological activity. However, low response rates, adverse side effects, and high costs compromise the additional benefits for patients treated with current chemical and biological agents. Chinese herbal medicines (CHMs) are a potential treasure trove of natural medicines and are gaining momentum in cancer immunomodulation with multi-component, multi-target, and multi-pathway characteristics. The active ingredient extracted from CHMs benefit generalized patients through modulating immune response mechanisms. Additionally, the introduction of nanotechnology has greatly improved the pharmacological qualities of active ingredients through increasing the hydrophilicity, stability, permeability, and targeting characteristics, further enhancing anti-cancer immunity. In this review, we summarize the mechanism of active ingredients for cancer immunomodulation, highlight nano-formulated deliveries of active ingredients for cancer immunotherapy, and provide insights into the future applications in the emerging field of nano-formulated active ingredients of CHMs.

Overcoming challenges in dermal and transdermal delivery of herbal therapeutics with polymeric microneedles

Natural products are generally preferred medications owing to their low toxicity and irritancy potential. However, a good number of herbal therapeutics (HT) exhibit solubility, permeability and stability issues that eventually affect oral bioavailability. Transdermal administration has been successful in resolving some of these issues which has lead in commercialization of a few herbal transdermal products. Polymeric Microneedles (MNs) has emerged as a promising platform in transdermal delivery of HT that face problems in permeating the skin. Several biocompatible and biodegradable polymers used in the fabrication of MNs have been discussed. MNs have been exploited for cutaneous delivery of HT in management of skin ailments like skin cancer, acne, chronic wounds and hypertrophic scar. Considering the clinical need, MNs are explored for systemic delivery of potent HT for management of diverse disorders like asthma, disorders of central nervous system and nicotine replacement as it obviates first pass metabolism and elicits a quicker onset of therapeutic response. MNs of HT have found good number of aesthetic applications in topical delivery of HT to the skin. Interestingly, MNs have emerged as an attractive option as a minimally invasive diagnostic aid in sampling biomarkers from plants, skin and ocular interstitial fluid. The review updates the progress made by MN technology of HT for multiple therapeutic interventions along with the future challenges. An attempt is made to illustrate the challenging formulation strategies employed in the fabrication of polymeric MNs of HT. Efforts are on to extend the potential applications of polymeric MNs to HT for diverse therapeutic applications.

Electrostatic-Interaction-Aided Microneedle Patch for Enhanced Glucose-Responsive Insulin Delivery and Three-Meal-Per-Day Blood-Glucose Regulation

The phenylborate-ester-cross-linked hydrogel microneedle patch (MNP) was promising in the diabetic field for the glucose-responsive insulin-delivering property and simple fabrication process. However, the unfit design of the charging microneedle network limited the improvement of blood-glucose regulating performances. In this work, insulin-loaded phenylborate-ester-cross-linked MNPs, with the polyzwitterion property, were constructed based on the modified ε-polylysine and poly(vinyl alcohol). The relationship between the charging nature of the MNP network and insulin release was verified by regulating the content of postprotonated positively charged amino groups. The elaborately designed MNP possessed improved glucose-responsive insulin-delivering performance. The in vivo study revealed the satisfactory results on blood-glucose regulation by the optimized MNP under the mimic three-meal-per-day mode. Moreover, the insulin bioactivity in the MNP could be maintained for 2 weeks under 25 °C. In summary, this work developed an effective strategy to improve the glucose-responsive phenylborate-ester-cross-linked MNP and enhance its potential for clinical transformation.

Evidence of Potential Natural Products for the Management of Hypertrophic Scars

Hypertrophic scarring is an aberrant wound-healing response to reestablish dermal integrity after an injury and can cause significant abnormalities in physical, aesthetic, functional, and psychological symptoms, impacting the patient's quality of life. There is currently no gold standard for preventing and treating hypertrophic scars. Therefore, many researchers have attempted to search for antihypertrophic scar agents with greater efficacy and fewer side effects. Natural therapeutics are becoming attractive as potential alternative anti-scarring agents because of their high efficacy, safety, biocompatibility, low cost, and easy accessibility. This review demonstrates various kinds of natural product-based therapeutics, including onion, vitamin E, Gotu kola, green tea, resveratrol, emodin, curcumin, and others, in terms of their mechanisms of action, evidence of efficacy and safety, advantages, and disadvantages when used as anti-scarring agents. We reviewed the literature based on data from in vitro, in vivo, and clinical trials. A total of 23 clinical trials were identified in this review; most clinical trials were ranked as having uncertain results (level of evidence 2b; n = 16). Although these natural products showed beneficial effects in both in vitro and in vivo studies of potential anti-scarring agents, there was limited clinical evidence to support their efficacy due to the limited quality of the studies, with individual flaws including small sample sizes, poor randomization, and blinding, and short follow-up durations. More robust and well-designed clinical trials with large-scale and prolonged follow-up durations are required to clarify the benefits and risks of these agents.

Tiny titans- unravelling the potential of polysaccharides and proteins based dissolving microneedles in drug delivery and theranostics: A comprehensive review

In recent years, microneedles (MNs) have emerged as a promising alternative to traditional drug delivery systems in transdermal drug delivery. The use of MNs has demonstrated significant potential in improving patient acceptance and convenience while avoiding the invasiveness of traditional injections. Dissolving, solid, hollow, coated, and hydrogel microneedles are among the various types studied for drug delivery. Dissolving microneedles (DMNs), in particular, have gained attention for their safety, painlessness, patient convenience, and high delivery efficiency. This comprehensive review primarily focuses on different types of microneedles, fabrication methods, and materials used in fabrication of DMNs such as hyaluronic acid, chitosan, alginate, gelatin, collagen, silk fibroin, albumin, cellulose and starch, to list a few. The review also provides an exhaustive discussion on the applications of DMNs, including the delivery of vaccines, cosmetic agents, contraceptives, hormone and genes, and other therapeutic applications like for treating cancer, skin diseases, and diabetes, among others, are covered in this review. Additionally, this review highlights some of the DMN systems that are presently undergoing clinical trials. Finally, the review discusses current advances and trends in DMNs, as well as future prospective directions for this ground-breaking technology in drug delivery.

Metallic elements combine with herbal compounds upload in microneedles to promote wound healing: a review

Wound healing is a dynamic and complex restorative process, and traditional dressings reduce their therapeutic effectiveness due to the accumulation of drugs in the cuticle. As a novel drug delivery system, microneedles (MNs) can overcome the defect and deliver drugs to the deeper layers of the skin. As the core of the microneedle system, loaded drugs exert a significant influence on the therapeutic efficacy of MNs. Metallic elements and herbal compounds have been widely used in wound treatment for their ability to accelerate the healing process. Metallic elements primarily serve as antimicrobial agents and facilitate the enhancement of cell proliferation. Whereas various herbal compounds act on different targets in the inflammatory, proliferative, and remodeling phases of wound healing. The interaction between the two drugs forms nanoparticles (NPs) and metal-organic frameworks (MOFs), reducing the toxicity of the metallic elements and increasing the therapeutic effect. This article summarizes recent trends in the development of MNs made of metallic elements and herbal compounds for wound healing, describes their advantages in wound treatment, and provides a reference for the development of future MNs.

Microneedle-mediated drug delivery for scar prevention and treatment

Scars are an inevitable natural outcome of most wound healing processes and affect skin functions, leading to cosmetic, psychological and social problems. Several strategies, including surgery, radiation, cryotherapy, laser therapy, pressure therapy and corticosteroids, can be used to either prevent or treat scars. However, these strategies are ineffective, have side effects and are typically expensive. Microneedle (MN) technology is a powerful, minimally invasive platform for transdermal drug delivery. This review discusses the most recent progress in MN-mediated drug delivery to prevent and treat pathological scars (hypertrophic and keloids). A comprehensive overview of existing challenges and future perspectives is also provided.

Applications and recent advances in transdermal drug delivery systems for the treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic, systemic autoimmune disease predominantly based on joint lesions with an extremely high disability and deformity rate. Several drugs have been used for the treatment of rheumatoid arthritis, but their use is limited by suboptimal bioavailability, serious adverse effects, and nonnegligible first-pass effects. In contrast, transdermal drug delivery systems (TDDSs) can avoid these drawbacks and improve patient compliance, making them a promising option for the treatment of rheumatoid arthritis (RA). Of course, TDDSs also face unique challenges, as the physiological barrier of the skin makes drug delivery somewhat limited. To overcome this barrier and maximize drug delivery efficiency, TDDSs have evolved in terms of the principle of transdermal facilitation and transdermal facilitation technology, and different generations of TDDSs have been derived, which have significantly improved transdermal efficiency and even achieved individualized controlled drug delivery. In this review, we summarize the different generations of transdermal drug delivery systems, the corresponding transdermal strategies, and their applications in the treatment of RA.

The Progress in the Application of Dissolving Microneedles in Biomedicine

In recent years, microneedle technology has been widely used for the transdermal delivery of substances, showing improvements in drug delivery effects with the advantages of minimally invasive, painless, and convenient operation. With the development of nano- and electrochemical technology, different types of microneedles are increasingly being used in other biomedical fields. Recent research progress shows that dissolving microneedles have achieved remarkable results in the fields of dermatological treatment, disease diagnosis and monitoring, and vaccine delivery, and they have a wide range of application prospects in various biomedical fields, showing their great potential as a form of clinical treatment. This review mainly focuses on dissolving microneedles, summarizing the latest research progress in various biomedical fields, providing inspiration for the subsequent intelligent and commercial development of dissolving microneedles, and providing better solutions for clinical treatment.

Going below and beyond the surface: Microneedle structure, materials, drugs, fabrication, and applications for wound healing and tissue regeneration

Microneedle, as a novel drug delivery system, has attracted widespread attention due to its non-invasiveness, painless and simple administration, controllable drug delivery, and diverse cargo loading capacity. Although microneedles are initially designed to penetrate stratum corneum of skin for transdermal drug delivery, they, recently, have been used to promote wound healing and regeneration of diverse tissues and organs and the results are promising. Despite there are reviews about microneedles, few of them focus on wound healing and tissue regeneration. Here, we review the recent advances of microneedles in this field. We first give an overview of microneedle system in terms of its potential cargos (e.g., small molecules, macromolecules, nucleic acids, nanoparticles, extracellular vesicle, cells), structural designs (e.g., multidrug structures, adhesive structures), material selection, and drug release mechanisms. Then we briefly summarize different microneedle fabrication methods, including their advantages and limitations. We finally summarize the recent progress of microneedle-assisted wound healing and tissue regeneration (e.g., skin, cardiac, bone, tendon, ocular, vascular, oral, hair, spinal cord, and uterine tissues). We expect that our article would serve as a guideline for readers to design their microneedle systems according to different applications, including material selection, drug selection, and structure design, for achieving better healing and regeneration efficacy.

Establishment of FAP-overexpressing Cells for FAP-targeted Theranostics

OBJECTIVE

Fibroblast activation protein (FAP) has been widely studied and exploited for its clinical applications. One of the difficulties in interpreting reports of FAP-targeted theranostics is due to the lack of accurate controls, making the results less specific and less confirmative. This study aimed to establish a pair of cell lines, in which one highly expresses FAP (HT1080-hFAP) and the other has no detectable FAP (HT1080-vec) as control, to accurately evaluate the specificity of the FAP-targeted theranostics in vitro and in vivo.

METHODS

The cell lines of the experimental group (HT1080-hFAP) and no-load group (HT1080-vec) were obtained by molecular construction of the recombinant plasmid pIRES-hFAP. The expression of hFAP in HT1080 cells was detected by PCR, Western blotting and flow cytometry. CCK-8, Matrigel transwell invasion assay, scratch test, flow cytometry and immunofluorescence were used to verify the physiological function of FAP. The activities of human dipeptidyl peptidase (DPP) and human endopeptidase (EP) were detected by ELISA in HT1080-hFAP cells. PET imaging was performed in bilateral tumor-bearing nude mice models to evaluate the specificity of FAP.

RESULTS

RT-PCR and Western blotting demonstrated the mRNA and protein expression of hFAP in HT1080-hFAP cells but not in HT1080-vec cells. Flow cytometry confirmed that nearly 95% of the HT1080-hFAP cells were FAP positive. The engineered hFAP on HT1080 cells had its ability to retain enzymatic activities and a variety of biological functions, including internalization, proliferation-, migration-, and invasion-promoting activities. The HT1080-hFAP xenografted tumors in nude mice bound and took up ⁶⁸GA-FAPI-04 with superior selectivity. High image contrast and tumor-organ ratio were obtained by PET imaging. The HT1080-hFAP tumor retained the radiotracer for at least 60 min.

CONCLUSION

This pair of HT1080 cell lines was successfully established, making it feasible for accurate evaluation and visualization of therapeutic and diagnostic agents targeting the hFAP.

Co-Delivery of Loxoprofen and Tofacitinib by Photothermal Microneedles for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is an autoimmune disease of synovial inflammation that affects populations worldwide. Transdermal drug delivery systems for treating RA have increased but remain challenging. We fabricated a dissolving microneedle (MN) system with photothermal (PT) polydopamine (PDA) to co-load the non-steroidal anti-inflammatory drug loxoprofen (Lox) and the Janus kinase inhibitor tofacitinib (Tof), with the aim of co-delivering Lox and Tof directly to the articular cavity, aided by the combination of MN and PT. In vitro and in vivo permeation studies showed that the PT MN significantly promoted drug permeation and retention in the skin. An in vivo visualization of the drug distribution in the articular cavity showed that the PT MN significantly promoted drug retention in the articular cavity. Importantly, compared to the intra-articular injection of Lox and Tof, the application of the PT MN to a carrageenan/kaolin-induced arthritis rat model exhibited superior performance in reducing joint swelling, muscle atrophy, and cartilage destruction. Furthermore, the PT MN downregulated the mRNA expression levels of proinflammatory cytokines, including TNF-α, IL-1β, iNOS, JAK2, JAK3, and STAT3. The results show that the PT MN transdermal co-delivery of Lox and Tof is a new synergetic therapy with high compliance and good therapeutic efficacy for RA.

3D-printed morphology-customized microneedles: understanding the correlation between their morphologies and the received qualities

Despite remarkable progress in the last decade in transdermal microneedle drug delivery systems, great difficulties in precisely manufacturing microneedles with sophisticated microstructures still strongly retard their practical applications. Herein we propose morphology-customized microneedles (spiral, conical, cylindroid, ring-like, arrow-like and tree-like) fabricated by stereolithography (SLA) based 3D-printing technique, and in-depth investigate the correlation between the customized morphologies and the received qualities of the corresponding microneedles such as the mechanical properties and skin penetration behavior, drug loading capacity and the drug release profiles. Results indicated that 3D-printed morphology-customized microneedles not only enhanced the mechanical strength but also improved both drug loading capacity and drug release behavior, which resulted from their highly controllable and 3D-printable morphologies (surface area and volume). And the in vivo study demonstrated that the 3D-printed morphology-customized microneedles successfully promoted the transdermal delivery of the loaded drug (verapamil hydrochloride) with an enhanced therapeutic efficacy for the treatment of hypertrophic scar.

Enhanced skin drug delivery using dissolving microneedles: a potential approach for the management of skin disorders

INTRODUCTION

For decades, finding effective long-term or disease-modifying treatments for skin disorders has been a major focus of scientists. The conventional drug delivery systems showed poor efficacy with high doses and are associated with side effects, which lead to challenges in adherence to therapy. Therefore, to overcome the limitations of conventional drug delivery systems, drug delivery research has focused on topical, transdermal, and intradermal drug delivery systems. Among all, the dissolving microneedles have gained attention with a new range of advantages of drug delivery in skin disorders such as breaching skin barriers with minimal discomfort and its simplicity of application to the skin, which allows patients to administer it themselves.

AREAS COVERED

This review highlighted the insights into dissolving microneedles for different skin disorders in detail. Additionally, it also provides evidence for its effective utilization in the treatment of various skin disorders. The clinical trial status and patents for dissolving microneedles for the management of skin disorders are also covered.

EXPERT OPINION

The current review on dissolving microneedles for skin drug delivery is accentuating the breakthroughs achieved so far in the management of skin disorders. The output of the discussed case studies anticipated that dissolving microneedles can be a novel drug delivery strategy for the long-term treatment of skin disorders.

Transdermal delivery of Protocatechuic aldehyde using hyaluronic acid/gelatin-based microneedles for the prevention and treatment of hypertrophic scars

The formation of hypertrophic scar (HS) involves many pathological processes, such as reduced apoptosis in fibroblasts, excessive collagen deposition by fibroblasts, over-abundant angiogenesis, etc. The therapeutic effects of current treatments targeting one single pathological process are limited. Due to their diverse biological activities, natural products offer a potential solution to this issue. In this study reported herein, we investigated the effects of Protocatechuic aldehyde (PA) on both hypertrophic scar-derived fibroblasts (HSF) and vascular endothelial growth factor (VEGF)-stimulated human umbilical vein endothelial cells (HUVECs). Microneedles (MN) containing PA and hyaluronic acid (HA) or containing PA, HA, and gelatin were prepared by mixing PA stock solution with HA or HA/gelatin at a ratio of 1:10. The HS prevention and treatment outcomes of these HA-PA-MN and HA/gelatin-PA-MN were tested using a rabbit ear HS model. Our data indicate that PA induces apoptosis and reduces collagen deposition in HSF. In addition, PA attenuates VEGF-stimulated angiogenesis of HUVECs. Furthermore, HA-PA-MN or HA/gelatin-PA-MN are able to effectively penetrate the epidermis of the HS tissues and then quickly dissolve, enabling the fast release of PA directly into the dermis of the HS tissues. HA-PA-MN or HA/Gelatin-PA-MN have also been found to effectively prevent or alleviate HS in a rabbit ear HS model. In conclusion, this study demonstrates that PA can be used to prevent and treat HS by simultaneously regulating HSF and HUVECs, which offers a potential novel reagent for HS management.

Comparison of the efficacy of seven types of microneedles for treating a rabbit hypertrophic scar model

Microneedle technology can effectively suppress the formation of hypertrophic scarring in both animals and humans. Our previous research has revealed that this is due to the physical contact inhibition effect by using microneedles made of liquid-crystal polymers as the model device. One important factor we didn't study is the influence of the fabrication materials of microneedles. Therefore, this article examines this key point on a rabbit ear hypertrophic scar model. We monitor the thickness of the scars, and the expression of α-SMA and Ki-67 protein, and TGF-β1 mRNA in a period of 42 days. Among microneedles made of 6 polymeric materials and stainless steel, polymethylmethacrylate microneedles present superiority in all aspects including the reduction of tissue fibrosis, and the expression of α-SMA, Ki-67 protein and TGF-β1 mRNA. On the other hand, polycarbonates, polyurethane, and polylactic-co-glycolic acid microneedles could suppress three biomarker expressions.

Drug-loaded balloon with built-in NIR controlled tip-separable microneedles for long-effective arteriosclerosis treatment

Drug-eluting balloon (DEB) angioplasty has emerged as an effective treatment for cardiovascular and cerebrovascular diseases. However, distal embolism and late lumen restenosis could be caused by drug loss during DEB handling and rapid drug metabolization. Here, a drug-loaded balloon equipped with tip-separable microneedles on the balloon surface (MNDLB) was developed. Inbuilt near-infrared (NIR) ring laser inside the catheter inner shaft was introduced to activate the biodegradable microneedle tips for the first time. The drug-loaded tips thus could be embedded in the vasculature and then released antiproliferative drug - paclitaxel slowly via polymer degradation for more than half a year. A significant increase in drug delivery efficiency and superior therapeutic effectiveness compared with the standard DEB were demonstrated using an atherosclerosis rabbit model.

The most promising microneedle device: present and future of hyaluronic acid microneedle patch

Microneedle patch (MNP) is an alternative to the oral route and subcutaneous injection with unique advantages such as painless administration, good compliance, and fewer side effects. Herein, we report MNP as a prominent strategy for drug delivery to treat local or systemic disease. Hyaluronic acid (HA) has advantageous properties, such as human autologous source, strong water absorption, biocompatibility, and viscoelasticity. Therefore, the Hyaluronic acid microneedle patch (HA MNP) occupies a large part of the MNP market. HA MNP is beneficial for wound healing, targeted therapy of certain specific diseases, extraction of interstitial skin fluid (ISF), and preservation of drugs. In this review, we summarize the benefits of HA and cross-linked HA (x-HA) as an MNP matrix. Then, we introduce the types of HA MNP, delivered substances, and drug distribution. Finally, we focus on the biomedical application of HA MNP as an excellent drug carrier in some specific diseases and the extraction and analysis of biomarkers. We also discuss the future development prospect of HA MNP in transdermal drug delivery systems (TDDS).

Advances in microneedles for delivery of active ingredients of natural herbals

The active ingredients of natural herbs have been extracted to act on different targets in the body to exert multiple effects. However, traditional oral administration and intravenous injection of herbal medicines are also susceptible to many side effects. Transdermal drug delivery by microneedles can overcome the shortcomings of these traditional drug delivery systems. The active ingredients of natural herbs can be delivered to the dermis or the connective tissue layer by five types of microneedles: solid, hollow, coated, dissolving, and hydrogel. Subsequently, the herbal ingredients are delivered to different target points of the body through body circulation to exert their effects. In this study, we classified the microneedles that can deliver the active ingredients of natural herbs and summarized their advantages and disadvantages as well as their preparation methods and applications, to guide the development and clinical applications of other herbal transdermal microneedles.

New opportunities and challenges of natural products research: When target identification meets single-cell multiomics

Natural products, and especially the active ingredients found in traditional Chinese medicine (TCM), have a thousand-year-long history of clinical use and a strong theoretical basis in TCM. As such, traditional remedies provide shortcuts for the development of original new drugs in China, and increasing numbers of natural products are showing great therapeutic potential in various diseases. This paper reviews the molecular mechanisms of action of natural products from different sources used in the treatment of inflammatory diseases and cancer, introduces the methods and newly emerging technologies used to identify and validate the targets of natural active ingredients, enumerates the expansive list of TCM used to treat inflammatory diseases and cancer, and summarizes the patterns of action of emerging technologies such as single-cell multiomics, network pharmacology, and artificial intelligence in the pharmacological studies of natural products to provide insights for the development of innovative natural product-based drugs. Our hope is that we can make use of advances in target identification and single-cell multiomics to obtain a deeper understanding of actions of mechanisms of natural products that will allow innovation and revitalization of TCM and its swift industrialization and internationalization.

Traditional Chinese medicine for hypertrophic scars—A review of the therapeutic methods and potential effects

Hypertrophic scar (HS) is a typical pathological response during skin injury, which can lead to pain, itching, and contracture in patients and even affect their physical and mental health. The complexity of the wound healing process leads to the formation of HS affected by many factors. Several treatments are available for HS, whereas some have more adverse reactions and can even cause new injuries with exacerbated scarring. Traditional Chinese Medicine (TCM) has a rich source, and most botanical drugs have few side effects, providing new ideas and methods for treating HS. This paper reviews the formation process of HS, the therapeutic strategy for HS, the research progress of TCM with its relevant mechanisms in the treatment of HS, and the related new drug delivery system of TCM, aiming to provide ideas for further research of botanical compounds in the treatment of HS, to promote the discovery of more efficient botanical candidates for the clinical treatment of HS, to accelerate the development of the new drug delivery system and the final clinical application, and at the same time, to promote the research on the anti-HS mechanism of multiherbal preparations (Fufang), to continuously improve the quality control and safety and effectiveness of anti-HS botanical drugs in clinical application.

Overcoming skin barriers through advanced transdermal drug delivery approaches

Upon exhaustive research, the transdermal drug delivery system (TDDS) has appeared as a potential, well-accepted, and popular approach to a novel drug delivery system. Ease of administration, easy handling, minimum systemic exposure, least discomfort, broad flexibility and tunability, controlled release, prolonged therapeutic effect, and many more perks make it a promising approach for effective drug delivery. Although, the primary challenge associated is poor skin permeability. Skin is an intact barrier that serves as a primary defense mechanism to preclude any foreign particle's entry into the body. Owing to the unique anatomical framework, i.e., compact packing of stratum corneum with tight junction and fast anti-inflammatory responses, etc., emerged as a critical physiological barrier for TDDS. Fusion with other novel approaches like nanocarriers, specially designed transdermal delivery devices, permeation enhancers, etc., can overcome the limitations. Utilizing such strategies, some of the products are under clinical trials, and many are under investigation. This review explores all dimensions that overcome poor permeability and allows the drug to attain maximum potential. The article initially compiles fundamental features, components, and design of TDDS, followed by critical aspects and various methods, including in vitro, ex vivo, and in vivo methods of assessing skin permeability. The work primarily aimed to highlight the recent advancement in novel strategies for effective transdermal drug delivery utilizing active methods like iontophoresis, electroporation, sonophoresis, microneedle, needleless jet injection, etc., and passive methods such as the use of liposomes, SLN, NLC, micro/nanoemulsions, dendrimers, transferosomes, and many more nanocarriers. In all, this compilation will provide a recent insight on the novel updates along with basic concepts, the current status of clinical development, and challenges for the clinical translation of TDDS.

A Novel lncRNA FPASL regulates fibroblasts proliferation via PI3K/AKT and MAPK signaling pathways in Hypertrophic scar

Hypertrophic scar is a problem for numerous patients, especially after burns, and is characterized by increased fibroblast proliferation and collagen deposition. Increasing evidence demonstrates that lncRNAs contribute to the development and progression of various diseases. However, the function of lncRNAs in hypertrophic scar formation remains poorly characterized. In this study, a novel fibroblast proliferation-associated lncRNA, named lncRNA FPASL (MSTRG.389905.1), which is mainly localized in the cytoplasm, is found to be downregulated in hypertrophic scar, as detected by lncRNA microarray and qRT-PCR. The full-length FPASL is characterized and further investigation confirms that it has no protein-coding potential. FPASL knockdown in fibroblasts triggers fibroblast proliferation, whereas overexpression of FPASL directly attenuates the proliferation of fibroblasts. Furthermore, target genes of the differentially expressed lncRNAs in hypertrophic scars and the matched adjacent normal tissues are enriched in fibroblast proliferation signaling pathways, including the PI3K/AKT and MAPK signaling pathways, as determined by GO annotation and KEGG enrichment analysis. We also demonstrate that knockdown of FPASL activates the PI3K/AKT and MAPK signaling pathways, and specific inhibitors of the PI3K/AKT and MAPK signaling pathways can reverse the proliferation of fibroblasts promoted by FPASL knockdown. Our findings contribute to a better understanding of the role of lncRNAs in hypertrophic scar and suggest that FPASL may act as a potential novel therapeutic target for hypertrophic scar.