Drug Penetration Research Articles

CAF to the Rescue! Potential and Challenges of Combination Antifungal Therapy for Reducing Morbidity and Mortality in Hospitalized Patients With Serious Fungal Infections.

The global burden of invasive fungal disease is substantial and escalating. Combination antifungal therapy (CAF) may improve patient outcomes by reducing development of resistance, improving drug penetration and rate of fungal clearance, and allowing for lower and less toxic antifungal drug doses; yet, increased cost, antagonism, drug-drug interactions, and toxicity are concerns. Clinical practice guidelines recommend antifungal monotherapy, rather than CAF, for most invasive fungal diseases due to a lack of comparative randomized clinical trials. An examination of the existing body of CAF research should frame new hypotheses and determine priorities for future CAF clinical trials. We performed a systematic review of CAF clinical studies for invasive candidiasis, cryptococcosis, invasive aspergillosis, and mucormycosis. Additionally, we summarized findings from animal models of CAF and assessed laboratory methods available to evaluate CAF efficacy. Future CAF trials should be prioritized according to animal models showing improved survival and observational clinical data supporting efficacy and safety.

Transcytosable and Ultrasound-Activated Liposome Enables Deep Penetration of Biofilm for Surgical Site Infection Management.

Biofilm-associated surgical site infection (BSSI) is a common and grievous postoperative complication lacking effective remedies, mainly due to the poor drug accumulation and penetration in the biofilms featured by dense extracellular polymeric substances (EPSs). Here, it is found that the vascular cell adhesion molecule-1 (VCAM1) is highly overexpressed in the vascular cells of BSSI. It is proposed that the combination of VCAM1-mediated transcytosis and ultrasonic cavitation can consecutively overcome the biological barriers of vascular endothelial cells and EPS for biofilm eradication. To demonstrate the feasibility, a VCAM1-targeted and ultrasound (US)-activated liposome (LPCOTML) loaded with a reactive-oxygen-species (ROS)-responsive lipoid prodrug of oleoyl meropenem, sonosensitizer of lipoid Ce6, and perfluoropentane is developed. LPCOTML can recognize the receptors on vascular cells, and initiate receptor-mediated transcytosis for transendothelial transport into the BSSI periphery. LPCOTML subsequently transforms from nanoparticle into microbubble via liquid-gas phase transition under US irradiation, triggering strong ultrasonic cavitation to blow up the EPS and deeply penetrate the biofilms. The sonosensitizer Ce6 induces ROS production under US irradiation and triggers the release of meropenem to induce potent antibacterial effect in a BSSI model. This study presents an effective strategy to tackle the biological barriers in BSSI via combining receptor-mediated transcytosis and ultrasonic cavitation.

Development and optimization of hydrogel-forming microneedles fabricated with 3d-printed molds for enhanced dermal diclofenac sodium delivery: a comprehensive in vitro, ex vivo, and in vivo study.

With the developing manufacturing technologies, the use of 3D printers in microneedle production is becoming widespread. Hydrogel-forming microneedles (HFMs), a variant of microneedles, demonstrate distinctive features such as a high loading capacity and controlled drug release. In this study, the conical microneedle master molds with approximately 500μm needle height and 250μm base diameter were created using a Stereolithography (SLA) 3D printer and were utilized to fabricate composite HFMs containing diclofenac sodium. Using Box-Behnken Design, the effects of different polymers on swelling index and mechanical strength of the developed HFMs were evaluated. The optimum HFMs were selected according to experimental design results with the aim of the highest mechanical strength with varying swelling indexes, which was needed to use 20% Gantrez S97 and 0.1% (F22), 0.42% (F23), and 1% (F24) hyaluronic acid. The skin penetration and drug release properties of the optimum formulations were assessed. Ex vivo studies were conducted on formulations to determine drug penetration and accumulation. F24, which has the highest mechanical strength and optimized swelling index, achieved the highest drug accumulation in the skin tissue (17.70 ± 3.66%). All optimum HFMs were found to be non-cytotoxic by the MTT cell viability test (> 70% cell viability). In in vivo studies, the efficacy of the F24 was assessed for the treatment of xylene-induced ear edema by contrasting it to the conventional dosage form. It was revealed that HFMs might be an improved replacement for conventional dosage forms in terms of dermal diseases such as actinic keratosis.

Anisotropic Hollow Structure with Chemotaxis Enabling Intratumoral Autonomic Therapy.

Effective intratumoral drug penetration is pivotal for successful cancer treatment. However, due to the disrupted capillary networks and poor perfusion in solid tumors, there exist challenges to realize autonomous directional drug penetration and controlled drug release within the tumor. Considering the specificity of glucose within tumor tissue, we draw inspiration from nature and engineer asymmetrical hollow structures exhibiting chemotaxis towards high glucose levels. By incorporating multiple shells into these structures, we enhance the local chemical concentration gradients, thereby improving cellular uptake and precise targeting. The advantages of anisotropic hollow multishell structure (a-HoMS) can be reflected from the diffusion coefficient and directivity, which increase by 73.4% and 265% respectively compared to conventional isotropic hollow spheres, achieving the most linear movement while ensuring the speed of movement. Furthermore, the multi-level porosity and temporal-spatial order of a-HoMS enable sequential drug delivery that inhibits angiogenesis with inducing cell apoptosis. After the eradication of localized tumor cells, the a-HoMS can automatically migrate to the alive tumor cells under the glucose gradient, inducing another cycle of drug delivery and chemotaxis, resulting in excellent antitumor efficacy. These anisotropic HoMS demonstrate intelligence, adaptability, and precision in tumor therapy, providing valuable insights for programmable treatment within tissues.

Anisotropic Hollow Structure with Chemotaxis Enabling Intratumoral Autonomic Therapy

Effective intratumoral drug penetration is pivotal for successful cancer treatment. However, due to the disrupted capillary networks and poor perfusion in solid tumors, there exist challenges to realize autonomous directional drug penetration and controlled drug release within the tumor. Considering the specificity of glucose within tumor tissue, we draw inspiration from nature and engineer asymmetrical hollow structures exhibiting chemotaxis towards high glucose levels. By incorporating multiple shells into these structures, we enhance the local chemical concentration gradients, thereby improving cellular uptake and precise targeting. The advantages of anisotropic hollow multishell structure (a‐HoMS) can be reflected from the diffusion coefficient and directivity, which increase by 73.4% and 265% respectively compared to conventional isotropic hollow spheres, achieving the most linear movement while ensuring the speed of movement. Furthermore, the multi‐level porosity and temporal‐spatial order of a‐HoMS enable sequential drug delivery that inhibits angiogenesis with inducing cell apoptosis. After the eradication of localized tumor cells, the a‐HoMS can automatically migrate to the alive tumor cells under the glucose gradient, inducing another cycle of drug delivery and chemotaxis, resulting in excellent antitumor efficacy. These anisotropic HoMS demonstrate intelligence, adaptability, and precision in tumor therapy, providing valuable insights for programmable treatment within tissues.

An Automated Digital Microfluidic System Based on Inkjet Printing

Cellular interactions, such as intercellular communication and signal transduction, can be enhanced within three-dimensional cell spheroids, contributing significantly to cellular viability and proliferation. This is crucial for advancements in cancer research, drug testing, and personalized medicine. The dimensions of the cell spheroids play a pivotal role in their functionality, affecting cell proliferation and differentiation, intercellular interactions, gene expression, protein synthesis, drug penetration, and metabolism. Consequently, different spheroid sizes may be required for various drug sensitivity experiments. However, conventional 3D cell spheroid cultures suffer from challenges such as size inconsistency, poor uniformity, and low throughput. To address these issues, we have developed an automated, intelligent system based on inkjet printing. This system allows for precise control of droplet volume by adjusting algorithms, thereby enabling the formation of spheroids of varying sizes. For spheroids of a single size, the printing pattern can be modified to achieve a coefficient of variation within 10% through a bidirectional compensation method. Furthermore, the system is equipped with an automatic pipetting module, which facilitates the high-throughput preparation of cell spheroids. We have implemented a 3 × 3 spheroid array in a 24-well plate, printing a total of 216 spheroids in just 11 min. Last, we attempted to print mouse small intestinal organoids and cultured them for 7 days, followed by immunofluorescent staining experiments. The results indicate that our equipment is capable of supporting the culture of organoids, which is of great significance for high-throughput drug screening and personalized medicine.

Recent Patents and Applications of Nanoemulsion and Nanoemulgel for Topical Drug Delivery

Nanocarriers like nanoemulsions and nanoemulgels have emerged as revolutionary platforms in the realm of topical drug delivery, addressing many limitations of traditional dosage forms. Conventional methods often struggle with challenges such as poor skin penetration, inconsistent drug targeting, and potential local toxicity, which can undermine therapeutic outcomes and patient adherence. Nanoemulsions, with their submicron-sized droplets, offer a promising solution by enhancing the delivery and bioavailability of therapeutic agents, especially those that are poorly soluble. Nanoemulgels further elevate this potential by providing a versatile vehicle for lipophilic drugs, overcoming the limitations of traditional formulations. These advanced formulations not only improve drug penetration through the skin but also expand the range of active compounds viable for clinical use. Their ability to target specific skin regions more effectively reduces adverse reactions and increases therapeutic efficacy. This article delves into the physicochemical properties, preparation techniques, and latest advancements in nanoemulsions and nanoemulgels. By exploring recent clinical trials and patents, the review provides valuable insights into the development and optimization of these cutting-edge topical drug delivery systems, offering a promising avenue for enhancing dermatological treatments and patient outcomes.

Enhancing the tissue penetration to improve sonodynamic immunotherapy for pancreatic ductal adenocarcinoma using membrane-camouflaged nanoplatform.

Sonodynamic therapy (SDT) is a promising strategy as an "in situ vaccine" to enhance activation of antitumor immune responses in solid tumors. However, the dense extracellular matrix (ECM) in pancreatic ductal adenocarcinoma (PDAC) lead to hypoxia and limited penetration of most drugs, aggravating the immunosuppressive tumor microenvironment and limiting the efficacy of synergistic sonodynamic immunotherapy. Therefore, it is essential to regulate ECM in order to alleviate tumor hypoxia and enhance the efficacy of sonodynamic immunotherapy for PDAC. The CPIM nanoplatform, consisting of a macrophage membrane-coated oxygen and drug delivery system (CM@PFOB-ICG-α-Mangostin), was synthesized using ultrasound and extrusion methods. The in vivo homologous targeting and hypoxia alleviation capabilities of CPIM were evaluated through near-infrared (NIR) imaging and photoacoustic (PA) imaging. The tumor growth inhibition potential and ability to reprogram the tumor microenvironment by the CPIM nanoplatform were also investigated. Co-delivery of α-Mangostin inhibits CAFs and enhances stromal depletion, thereby facilitating better infiltration of macromolecules. Additionally, the nanoemulsion containing perfluorocarbon (PFC) can target tumor cells and accumulate within them through homologous targeting. The US irradiation results in the rapid release of oxygen, serving as a potential source of sonodynamic therapy for hypoxic tumors. Moreover, CPIM reshapes the immunosuppressive microenvironment increasing the population of cytotoxic T lymphocytes (CTLs), and enhancing their anti-tumor immune response through the use of anti-PDL1 antibodies to block immune checkpoints. The present study offers a potential strategy for the co-delivery of oxygen and α-Mangostin, aiming to enhance the penetration of tumors to improve SDT. This approach effectively addresses the existing limitations of immune checkpoint blockade (ICB) treatment in solid tumors, while simultaneously boosting the immune response through synergistic sonodynamic immunotherapy.

All Blood Brain Barrier Cell Types Demonstrate Capability to Influence Differential Tenofovir and Emtricitabine Metabolism and Transport in the Brain.

The blood brain barrier (BBB) represents a significant obstacle in brain drug penetration that challenges efforts in the treatment of neurological disorders. Therapeutically targeting the brain requires interactions with each BBB cell type, including endothelial cells, pericytes, and astrocytes. Yet, the relative contribution of these BBB cell types to the mechanisms that facilitate brain drug disposition is not well characterized. Here, we use first-line antiretroviral therapies, tenofovir (TFV) and emtricitabine (FTC), as models to investigate the mechanisms of drug transport and metabolism at the BBB that may influence access of the drug to the brain. We evaluated regional and cell-type-specific drug metabolism and transport mechanisms using rhesus macaques and in vitro treatment of primary human cells. We report heterogeneous distribution of TFV, FTC, and their active metabolites, which cerebrospinal fluid measures could not reflect. We found that all BBB cell types possessed functional drug-metabolizing enzymes and transporters that promoted TFV and FTC uptake and pharmacologic activation. Pericytes and astrocytes emerged as pharmacologically dynamic cells that rival hepatocytes and were uniquely susceptible to modulation by disease and treatment. Together, our findings demonstrate the importance of considering the BBB as a unique pharmacologic entity rather than viewing it as an extension of the liver, as each cell type possesses distinct drug metabolism and transport capacities that contribute to differential brain drug disposition. Further, our work highlights pharmacologically active pathways at the BBB that may regulate brain drug disposition and impact therapeutic efforts to alleviate neurologic disease.

Tethered gold-liposome nanoparticles for iontophoresis-enhanced topical delivery for anti-inflammation

Topical delivery is a widely utilized drug administration route globally due to its convenience, non-invasiveness, and minimal drug metabolism. However, the skin barrier, particularly the stratum corneum (SC), poses a challenge by hindering drug absorption and permeation. To address this issue, green-synthesized gold nanoparticles (AuG) were loaded into liposomes to increase electron density and facilitate cathodal iontophoresis for topical drug delivery enhancement. Ginger rhizome extract served as a model hydrophobic compound encapsulated within the gold-liposomes to evaluate its anti-inflammatory effect. Our study demonstrated that the ginger-gold loaded liposomes (AuGL) enhanced cellular uptake of the hydrophobic payload and improved drug penetration through skin layers compared to conventional liposomes following iontophoresis. We investigated different ratios of gold nanoparticles to liposomes and characterized the nanoparticles using DLS, TEM, and FT-IR. Additionally, AuGL significantly inhibited nitric oxide release and TNF-α in RAW 264.7 cells. Furthermore, we formulated AuGL-loaded topical emulgel, which exhibited good stability under accelerated conditions. Our findings suggest that the AuGL combined with iontophoresis offers superior benefits for topical drug delivery, potentially enabling the treatment of skin inflammations and inflammation-related skin cancers.

Microorganism microneedle micro-engine depth drug delivery

As a transdermal drug delivery method, microneedles offer minimal invasiveness, painlessness, and precise in-situ treatment. However, current microneedles rely on passive diffusion, leading to uncontrollable drug penetration. To overcome this, we developed a pneumatic microneedle patch that uses live Enterobacter aerogenes as microengines to actively control drug delivery. These microbes generate gas, driving drugs into deeper tissues, with adjustable glucose concentration allowing precise control over the process. Our results showed that this microorganism-powered system increases drug delivery depth by over 200%, reaching up to 1000 μm below the skin. In a psoriasis animal model, the technology effectively delivered calcitriol into subcutaneous tissues, offering rapid symptom relief. This innovation addresses the limitations of conventional microneedles, enhancing drug efficiency, transdermal permeability, and introducing a creative paradigm for on-demand controlled drug delivery.

Innovative Use of Nanomaterials in Treating Retinopathy of Prematurity

Background/Objectives: Retinopathy of prematurity (ROP) is a severe condition primarily affecting premature infants with a gestational age (GA) of 30 weeks or less and a birth weight (BW) of 1500 g or less. The objective of this review is to examine the risk factors, pathogenesis, and current treatments for ROP, such as cryotherapy, laser photocoagulation, and anti-VEGF therapy, while exploring the limitations of these approaches. Additionally, this review evaluates emerging nanotherapeutic strategies to address these challenges, aiming to improve ROP management. Methods: A comprehensive literature review was conducted to gather data on the pathogenesis, traditional treatment methods, and novel nanotherapeutic approaches for ROP. This included assessing the efficacy and safety profiles of cryotherapy, laser treatment, anti-VEGF therapy, and nanotherapies currently under investigation. Results: Traditional treatments, while effective in reducing disease progression, exhibit limitations, including long-term complications, tissue damage, and systemic side effects. Nanotherapeutic approaches, on the other hand, have shown potential in offering targeted drug delivery with reduced systemic toxicity, improved ocular drug penetration, and sustained release, which could decrease the frequency of treatments and enhance therapeutic outcomes. Conclusions: Nanotherapies represent a promising advancement in ROP treatment, offering safer and more effective management strategies. These innovations could address the limitations of traditional therapies, reducing complications and improving outcomes for premature infants affected by ROP. Further research is needed to confirm their efficacy and safety in clinical practice.

Scanning Transmission Soft X-Ray Microscopy Probes Topical Drug Delivery of Rapamycin Facilitated by Microneedles.

Scanning Transmission X-ray microscopy (STXM) is a sensitive and selective probe for the penetration of rapamycin which is topically applied to human skin ex vivo and is facilitated by skin treatment with microneedles puncturing the skin. Inner-shell excitation serves as a selective probe for detecting rapamycin by changes in optical density as well as linear combination modeling using reference spectra of the most abundant species. The results indicate that mechanical damage induced by microneedles allows this drug to accumulate in the stratum corneum without reaching the viable skin layers. This is unlike intact skin which shows no drug penetration at all and underscores the mechanical impact of microneedle skin treatment. These results are compared to drug penetration profiles of other drugs highlighting the importance of skin barriers. High spatial resolution studies also indicate that the lipophilic drug rapamycin is observed in corneocytes. Attempts in data evaluation are reported to probe rapamycin also in the lipid layers between the corneocytes, which was not accomplished before. These results are compared to recent results on rapamycin uptake in skin where barrier impairment was induced by pre-treatment with the enzyme trypsin and drug formulations leading to occlusion.

Utilizing an Ex Vivo Skin Penetration Analysis Model for Predicting Ocular Drug Penetration: A Feasibility Study with Curcumin Formulations

Objective: This study aimed to investigate the feasibility of using the digital image processing technique, developed to semi-quantitatively study dermal penetration, to study corneal penetration in an ex vivo porcine eye model. Here, we investigated various formulation strategies intended to enhance dermal and corneal bioavailability of the model hydrophobic drug, curcumin. Methods: Several formulation principles were explored, including oily solutions, oily suspensions, aqueous nanosuspension, micelles, liposomes and cyclodextrins. The dermal penetration efficacy was tested using an ex vivo porcine ear model previously developed at Philipps-Universität Marburg with subsequent digital image processing. This image analysis method was further applied to study corneal penetration using an ex vivo porcine whole-eye model. Results: For dermal penetration, oily solutions, oily suspensions and nanosuspensions exhibited the least penetration, whereas liposomes and cyclodextrins showed enhanced penetration. Corneal curcumin penetration correlated with dermal penetration, with curcumin loaded into cyclodextrins penetrating the deepest. Conclusions: Overall, our study suggests that the image analysis method previously developed for ex vivo skin penetration can easily be repurposed to study corneal penetration of hydrophobic drugs.

Multifunctional Hydrogel Microneedle Patches Modulating Oxi-inflamm-aging for Diabetic Wound Healing.

Oxidative stress, chronic inflammation, and immune senescence are important pathologic factors in diabetic wound nonhealing. This study loads taurine (Tau) into cerium dioxide (CeO2) to develop CeO2@Tau nanoparticles with excellent antioxidant, anti-inflammatory, and anti-aging properties. To enhance the drug penetration efficiency in wounds, CeO2@Tau is encapsulated in gelatin methacryloyl (GelMA) hydrogel to prepare CeO2@Tau@Hydrogel@Microneedle (CTH@MN) patch system. Microneedle technology achieves precise and efficient delivery of CeO2@Tau, ensuring their deep penetration into the wound tissue for optimal efficacy. Rigorous in vitro and in vivo tests have confirmed the satisfactory therapeutic effect of CTH@MN patch on diabetic wound healing. Mechanistically, CTH@MN attenuates oxidative damage and inflammatory responses in macrophages by inhibiting the ROS/NF-κB signaling pathway. Meanwhile, CTH@MN activated autophagy-mediated anti-aging activity, creating a favorable immune microenvironment for tissue repair. Notably, in a diabetic mouse wound model, the multifunctional CTH@MN patch significantly promotes wound healing by systematically regulating the oxidation-inflammation-aging (oxi-inflamm-aging) pathological axis. In conclusion, the in-depth exploration of the CTH@MN system in this study provides new strategies and perspectives for treating diabetic non-healing wounds.

Studies on drug delivery from dissolving microneedle and its uptake in tissue

Abstract In this study, a mathematical model for transdermal drug administration using a dissolving conical microneedle (MN) is developed. The drug is absorbed in the blood compartment after passing through the skin’s viable epidermis. Reversible reaction kinetics then allow the drug to enter the tissue compartment. An unsteady reaction equation is used to predict the drug’s distribution into the skin following MN’s dissolution. An unsteady reaction mechanism is used to determine the concentrations in the blood and tissue compartments. Using the fourth-order Runge–Kutta method, the governing equations with their initial conditions are solved numerically. The MN is expected to dissolve completely in 108.1 s, according to the predicted results, while the concentration in the skin peaks at 94.4 s. The concentrations in the tissue and blood compartments, however, reach their respective maximal amounts later on. In this investigation, the impacts of the drug’s mass fraction, volume fraction, and penetration rate cannot be completely ruled out. A thorough sensitivity analysis has been carried out for some of the parameters involved. Our findings closely align with the findings reported in the literature.

Development of transferosomes for topical ocular drug delivery of curcumin

BackgroundTransferosomes (TFS) are ultra-deformable elastic bilayer vesicles that have previously been used to enhance gradient driven penetration through the skin. This study aimed to evaluate the potential of TFS for topical ocular drug delivery and to compare their penetration enhancing properties in different ocular tissues. MethodsCurcumin-loaded TFS were prepared using Tween 80 as the edge activator. Drug release and precorneal retention of the TFS were evaluated in vitro, while their ocular biocompatibility and bioavailability were evaluated ex vivo using a curcumin solution in medium chain triglycerides as the oily control. ResultsThe TFS had a narrow size distribution with a particle size less than 150 nm and an entrapment efficiency greater than 99.96 %. Burst release from the TFS was minimal and the formulation showed good corneal biocompatibility. Moreover, enhanced corneal and conjunctival drug penetration with significantly greater and deeper drug delivery was observed with TFS. ConclusionTFS offer a promising platform for ocular delivery of hydrophobic drugs. This study, for the first time, elucidates the effect of tissue morphology and osmotic gradients on drug penetration in different ocular tissues.

GDNF and cAMP significantly enhance in vitro blood-brain barrier integrity in a humanized tricellular transwell model

Blood-brain barrier (BBB) is a crucial membrane safeguarding neural tissue by controlling the molecular exchange between blood and the brain. However, assessing BBB permeability presents challenges for central nervous system (CNS) drug development. In vitro studies of BBB-permeable agents before animal testing are essential to mitigate failures. Improved in vitro models are needed to mimic physiologically relevant BBB integrity. Here, we established an in vitro human-derived triculture BBB model, coculturing hCMEC/D3 with primary astrocytes and pericytes in a transwell format. This study found that the triculture BBB model exhibited significantly higher paracellular tightness (TEER 147.6 ± 6.5 Ω × cm2) than its monoculture counterpart (106.3 ± 1.0 Ω × cm2). Additionally, BBB permeability in the triculture model was significantly lower. While GDNF and cAMP have been shown to promote BBB integrity in monoculture models, their effect in our model was previously unreported. Our study demonstrates that both GDNF and cAMP increased TEER values (around 200 Ω × cm2 for each; 237.6 ± 17.7 Ω × cm2 for co-treatment) compared to untreated control, and decreased BBB permeability, mediated by increased claudin-5 expression. In summary, this humanized triculture BBB model, enhanced by GDNF and cAMP, offers an alternative for exploring in vitro drug penetration into the human brain.

A biodegradable lipid nanoparticle delivers a Cas9 ribonucleoprotein for efficient and safe in situ genome editing in melanoma

The development of melanoma is closely related to Braf gene, which is a suitable target for CRISPR/Cas9 based gene therapy. CRISPR/Cas9-sgRNA ribonucleoprotein complexes (RNPs) stand out as the safest format compared to plasmid and mRNA delivery. Similarly, lipid nanoparticles (LNPs) emerge as a safer alternative to viral vectors for delivering the CRISPR/Cas9-sgRNA gene editing system. Herein, we have designed multifunctional cationic LNPs specifically tailored for the efficient delivery of Cas9 RNPs targeting the mouse Braf gene through transdermal delivery, aiming to treat mouse melanoma. LNPs are given a positive charge by the addition of a newly synthesized polymer, deoxycholic acid modified polyethyleneimine (PEI-DOCA). Positive charge enables LNPs to be delivered in vivo by binding to negatively charged cell membranes and proteins, thereby facilitating efficient skin penetration and enhancing the delivery of RNPs into melanoma cells for gene editing purposes. Our research demonstrates that these LNPs enhance drug penetration through the skin, successfully delivering the Cas9 RNPs system and specifically targeting the Braf gene. Cas9 RNPs loaded LNPs exert a notable impact on gene editing in melanoma cells, significantly suppressing their proliferation. Furthermore, in mice experiments, the LNPs exhibited skin penetration and tumor targeting capabilities. This innovative LNPs delivery system offers a promising gene therapy approach for melanoma treatment and provides fresh insights into the development of safe and effective delivery systems for Cas9 RNPs in vivo. Statement of significanceCRISPR/Cas9 technology brings new hope for cancer treatment. Cas9 ribonucleoprotein offers direct genome editing, yet delivery challenges persist. For melanoma, transdermal delivery minimizes toxicity but faces skin barrier issues. We designed multifunctional lipid nanoparticles (LNPs) for Cas9 RNP delivery targeting the Braf gene. With metal microneedle pretreatment, our LNPs effectively edited melanoma cells, reducing Braf expression and inhibiting tumor growth. Our study demonstrates LNPs' potential for melanoma therapy and paves the way for efficient in vivo Cas9 RNP delivery systems in cancer therapy.

Advancements in the Transdermal Drug Delivery Systems Utilizing Microemulsion-based Gels.

Microemulsion gel, as a promising transdermal nanoparticle delivery system, addresses the limitations of microemulsions and enhances their performance in drug delivery and release. This article aims to discuss the advantages of microemulsion gel, including improved drug bioavailability, reduced drug irritation, enhanced drug penetration and skin adhesion, and increased antimicrobial properties. It explores the methods for selecting microemulsion formulations and the general processes of microemulsion preparation, as well as commonly used oil phases, surfactants, and co-surfactants. Additionally, the biomedical applications of microemulsion gel in treating conditions, such as acne and psoriasis, are also discussed. Overall, this article elucidates the significant potential of microemulsion gel in topical drug delivery, providing insights into future development and clinical applications.