Non-invasive Transdermal Delivery Research Articles

Non-Invasive Delivery of Negatively Charged Nanobodies by Anodal Iontophoresis: When Electroosmosis Dominates Electromigration.

Iontophoresis enables the non-invasive transdermal delivery of moderately-sized proteins and the needle-free cutaneous delivery of antibodies. However, simple descriptors of protein characteristics cannot accurately predict the feasibility of iontophoretic transport. This study investigated the cathodal and anodal iontophoretic transport of the negatively charged M7D12H nanobody and a series of negatively charged variants with single amino acid substitutions. Surprisingly, M7D12H and its variants were only delivered transdermally by anodal iontophoresis. In contrast, transdermal permeation after cathodal iontophoresis and passive diffusion was <LOQ. The anodal iontophoretic delivery of these negatively charged proteins was achieved because electroosmosis was the dominant electrotransport mechanism. Cutaneous deposition after the anodal iontophoresis of M7D12HWT (wild type), and the R54E and K65E variants, was statistically superior to that after cathodal iontophoresis (6.07 ± 2.11, 9.22 ± 0.80, and 14.45 ± 3.45 μg/cm2, versus 1.12 ± 0.30, 0.72 ± 0.27, and 0.46 ± 0.07 µg/cm2, respectively). This was not the case for S102E, where cutaneous deposition after anodal and cathodal iontophoresis was 11.89 ± 0.87 and 8.33 ± 2.62 µg/cm2, respectively; thus, a single amino acid substitution appeared to be sufficient to impact the iontophoretic transport of a 17.5 kDa protein. Visualization studies using immunofluorescent labeling showed that skin transport of M7D12HWT was achieved via the intercellular and follicular routes.

Non-invasive transdermal delivery of biomacromolecules with fluorocarbon-modified chitosan for melanoma immunotherapy and viral vaccines

Transdermal drug delivery has been regarded as an alternative to oral delivery and subcutaneous injection. However, needleless transdermal delivery of biomacromolecules remains a challenge. Herein, a transdermal delivery platform based on biocompatible fluorocarbon modified chitosan (FCS) is developed to achieve highly efficient non-invasive delivery of biomacromolecules including antibodies and antigens. The formed nanocomplexes exhibits effective transdermal penetration ability via both intercellular and transappendageal routes. Non-invasive transdermal delivery of immune checkpoint blockade antibodies induces stronger immune responses for melanoma in female mice and reduces systemic toxicity compared to intravenous injection. Moreover, transdermal delivery of a SARS-CoV-2 vaccine in female mice results in comparable humoral immunity as well as improved cellular immunity and immune memory compared to that achieved with subcutaneous vaccine injection. Additionally, FCS-based protein delivery systems demonstrate transdermal ability for rabbit and porcine skins. Thus, FCS-based transdermal delivery systems may provide a compelling opportunity to overcome the skin barrier for efficient transdermal delivery of bio-therapeutics.

Non-Invasive Transdermal Delivery of Antisense Oligonucleotides with Biocompatible Ionic Liquids.

Nucleic acid drugs, including antisense oligonucleotides (ASOs), have received considerable attention as novel therapeutics for the treatment of intractable diseases. Despite their potential benefits, ASOs are currently administered via injection, which can negatively impact patient quality of life because of the prevalence of severe injection site reactions. Non-invasive transdermal administration of ASOs is desirable but highly challenging owing to the strong barrier imposed by the stratum corneum, which only permits the penetration of small molecules under 500 Da. For ASOs to exert their antisense effect, they must traverse the negatively charged cell membrane and reach the cytoplasm. In this study, we used the solid-in-oil (S/O) dispersion technology to facilitate the skin permeation of ASOs by coating the drug with a hydrophobic surfactant molecule, specifically lipid-based ionic liquid (IL) surfactants with high biocompatibility and transdermal penetration-enhancing properties. To induce the antisense effect, it was important to achieve simultaneous transdermal delivery and intracellular entrapment of ASOs. In vitro investigations indicated that the newly prepared IL-S/O enhanced the transdermal penetration and intracellular delivery of ASOs, thus inhibiting mRNA translation of the target TGF-β. In addition, in vivo investigations of tumor-bearing mice suggested that the anti-tumor effect of the IL-S/O was similar to that of injection. This study demonstrates the potential of non-invasive transdermal delivery carriers based on biocompatible ILs, which can be applied to a variety of nucleic acid drugs.

Hydrogel-forming microarray patches with solid dispersion reservoirs for transdermal long-acting microdepot delivery of a hydrophobic drug.

Hydrogel-forming microarray patches (HF-MAPs) are used to circumvent the skin barrier and facilitate the noninvasive transdermal delivery of many hydrophilic substances. However, their use in the delivery of hydrophobic agents is a challenging task. This work demonstrates, for the first time, the successful transdermal long-acting delivery of the hydrophobic atorvastatin (ATR) via HF-MAPs using poly(ethylene)glycol (PEG)-based solid dispersion (SD) reservoirs. PEG-based SDs of ATR were able to completely dissolve within 90 s in vitro. Ex vivo results showed that 2.05 ± 0.23 mg of ATR/0.5 cm2 patch was delivered to the receiver compartment of Franz cells after 24 h. The in vivo study, conducted using Sprague Dawley rats, proved the versatility of HF-MAPs in delivering and maintaining therapeutically-relevant concentrations (> 20 ng·mL-1) of ATR over 14 days, following a single HF-MAP application for 24 h. The long-acting delivery of ATR suggests the successful formation of hydrophobic microdepots within the skin, allowing for the subsequent sustained delivery as they gradually dissolve over time, as shown in this work. When compared to the oral group, the use of the HF-MAP formulation improved the overall pharmacokinetics profile of ATR in plasma, where significantly higher AUC values resulting in ~10-fold higher systemic exposure levels were obtained. This novel system offers a promising, minimally-invasive, long-acting alternative delivery system for ATR that is capable of enhancing patient compliance and therapeutic outcomes. It also proposes a unique promising platform for the long-acting transdermal delivery of other hydrophobic agents.

Hyaluronate-Black Phosphorus-Upconversion Nanoparticle Complex for Non-invasive Theranosis of Skin Cancer.

Despite the wide investigation on black phosphorus (BP) for biophotonic applications, the finite depth of light penetration has limited further development of BP-based photomedicines. Here, we developed a hyaluronate-BP-upconversion nanoparticle (HA-BP-UCNP) complex for near-infrared (NIR) light-mediated multimodal theranosis of skin cancer with photoacoustic (PA) bioimaging, photodynamic therapy (PDT), and photothermal therapy (PTT). In contrast to the conventional BP-based skin cancer theranosis, the HA-BP-UCNP complex could be non-invasively delivered into the tumor tissue to induce the cancer cell apoptosis upon NIR light irradiation. The PA imaging of BP successfully visualized the non-invasive transdermal delivery of the HA-BP-UCNP complex into the mice skin. HA in the complex facilitated the transdermal delivery of BP into the tumor tissue under the skin. Upon 980 nm NIR light irradiation, the UCNP converted the light to UV-blue light to generate reactive oxygen species by sensitizing BP in the HA-BP-UCNP complex for PDT. Remarkably, 808 nm NIR irradiation with PTT triggered the apoptosis of tumor cells. Taken together, we could confirm the feasibility of the HA-BP-UCNP complex for NIR light-mediated multimodal theranosis of skin cancers.

Iontophoresis of Biological Macromolecular Drugs.

Over the last few decades, biological macromolecular drugs (e.g., peptides, proteins, and nucleic acids) have become a significant therapeutic modality for the treatment of various diseases. These drugs are considered superior to small-molecule drugs because of their high specificity and favorable safety profiles. However, such drugs are limited by their low oral bioavailability and short half-lives. Biological macromolecular drugs are typically administrated via invasive methods, e.g., intravenous or subcutaneous injections, which can be painful and induce needle phobia. Noninvasive transdermal delivery is an alternative administration route for the local and systemic delivery of biological macromolecular drugs. However, a challenge with the noninvasive transdermal delivery of biological macromolecular drugs is the outermost layer of the skin, known as the stratum corneum, which is a physical barrier that restricts the entry of extraneous macromolecules. Iontophoresis (IP) relies on the application of a low level of electricity for transdermal drug delivery, in order to facilitate the skin permeation of hydrophilic and charged molecules. The IP of several biological macromolecular drugs has recently been investigated. Herein, we review the IP-mediated noninvasive transdermal delivery of biological macromolecular drugs, their routes of skin permeation, their underlying mechanisms, and their advance applications.

Effective Anticancer Therapy by Combination of Nanoparticles Encapsulating Chemotherapeutic Agents and Weak Electric Current.

Delivery of medicines using nanoparticles via the enhanced permeability and retention (EPR) effect is a common strategy for anticancer chemotherapy. However, the extensive heterogeneity of tumors affects the applicability of the EPR effect, which needs to overcome for effective anticancer therapy. Previously, we succeeded in the noninvasive transdermal delivery of nanoparticles by weak electric current (WEC) and confirmed that WEC regulates the intercellular junctions in the skin by activating cell signaling pathways (J. Biol. Chem., 289, 2014, Hama et al.). In this study, we applied WEC to tumors and investigated the EPR effect with polyethylene glycol (PEG)-modified doxorubicin (DOX) encapsulated nanoparticles (DOX-NP) administered via intravenous injection into melanoma-bearing mice. The application of WEC resulted in a 2.3-fold higher intratumor accumulation of nanoparticles. WEC decreased the amount of connexin 43 in tumors while increasing its phosphorylation; therefore, the enhancing of intratumor delivery of DOX-NP is likely due to the opening of gap junctions. Furthermore, WEC combined with DOX-NP induced a significant suppression of tumor growth, which was stronger than with DOX-NP alone. In addition, WEC alone showed tumor growth inhibition, although it was not significant compared with non-treated group. These results are the first to demonstrate that effective anticancer therapy by combination of nanoparticles encapsulating chemotherapeutic agents and WEC.

Noninvasive Transdermal Delivery of Biomolecules Using Arc-Poration

Noninvasive Transdermal Delivery of Biomolecules Using Arc-Poration

Non-invasive transdermal delivery of chemotherapeutic molecules in vivo using superparamagnetic iron oxide nanoparticles

BackgroundThe skin is both a target and a potential conduit for the delivery of drugs, but its cornified cell layer resists penetration by most molecules. This study investigated the potential of superparamagnetic iron oxide nanoparticles to facilitate the transdermal delivery of anticancer agents.ResultsChemotherapeutic cancer drugs were applied with or without nanoparticles to the skin of hairless mice, and their ability to penetrate the skin was assessed using fluorescence microscopy and tumor growth. Nanoparticles enhanced the penetration of the skin by doxorubicin and 5-fluorouracil as determined by fluorescence microscopy and growth retardation of experimental melanoma in immunocompetent, syngeneic mice. This drug enhancement did not require conjugation or encapsulation of the drugs by the nanoparticles—simple co-administration sufficed. Nanoparticles applied topically to melanomas increased the cytotoxicity and immune cell infiltration induced by co-administered 5-fluorouracil, and also reduced vascularization of the tumors independently of 5-fluorouracil.ConclusionCorrectly formulated superparamagnetic iron oxide nanoparticles can facilitate the chemotherapeutic effectiveness of cytotoxic drugs on skin tumors by both increasing their transdermal penetration and ameliorating host–tumor interactions. This enhancement of skin penetration occurs without the need for conjugation or encapsulation of the co-administered drugs, and so will likely be applicable to other drugs, also.

Non-invasive Transdermal Delivery of Human Insulin Using Ionic Liquids: In vitro Studies.

In this research project, synthesis and characterization of ionic liquids and their subsequent utilization as facilitators of transdermal delivery of human insulin was pursued. Choline geranate and choline oleate ionic liquids (and their deep eutectic solvents) were produced and characterized by nuclear magnetic resonance (1H NMR), water content, oxidative stability, cytotoxicity and genotoxicity assays, and ability to promote transdermal protein permeation. The results gathered clearly suggest that all ionic liquids were able to promote/facilitate transdermal permeation of insulin, although to various extents. In particular, choline geranate 1:2 combined with its virtually nil cyto- and geno-toxicity was chosen to be incorporated in a biopolymeric formulation making it a suitable facilitator aiming at transdermal delivery of insulin.

Noninvasive transdermal delivery of liposomes by weak electric current.

Noninvasive transdermal drug delivery (NTDD) offers an exciting new method of administration relative to conventional routes, but is associated with some challenges. Liposomes are capable of encapsulating transdermally-unfavorable drugs. However, the horny layer of skin is a significant barrier that limits efficient transdermal delivery of liposomes. Iontophoresis using weak electric current (WEC) represents a NTDD technology. WEC treatment of liposomes applied to the skin surface improves transdermal penetration of encapsulated drugs by cooperative effects. In this review, we provide an overview of the application of WEC/liposomes for transdermal delivery of macromolecules and low molecular weight drugs. We compare the transdermal delivery and therapeutic efficiency of the combined system with conventional routes of administration and their individual use. We discuss a novel perspective on the mechanism of WEC-mediated transdermal delivery of liposomes, which suggests that WEC activates the intracellular signaling pathway for transdermal permeation and induces unique endocytosis in skin cells.

Optimized Transferosomal Bovine Lactoferrin (BLF) as a Promising Novel Non-Invasive Topical Treatment for Genital Warts Caused by Human Papiluma Virus (HPV).

Human papillomavirus (HPV) cause common warts, laryngeal papilloma, and genital condylomata and might lead to development of cervical cancer. Lactoferrin (LF) is a member of the transferrin family, which has antiviral activity against HPV-16. LF is an important player in the defense against pathogenic microorganisms and has also been shown to have activity against several viruses including herpesvirus, adenovirus, rotavirus, and poliovirus. Bovine LF (BLF) has been reported to be a more potent inhibitor of HPV entry in comparison to human LF. The goal of the present study is to formulate, evaluate and optimize transfersomal vesicles as a non-invasive transdermal delivery system which assumed to be a suitable for treatment of genital warts. Transfersomes have been prepared by two methods including reverse phase evaporation and thin film hydration with different ratios of cholesterol: lecithin: DOTAP in the presence of SDS or Tween 80. The transferosomes were then evaluated regarding size, polydispersity, and LF loading. In-vitro release studies in pH 5.3 and 7.4, stability evaluation in 4 °C and 25 °C, and TEM imaging hve been performed on optimized transferosomal lactoferrin. The optimized transferosomes were found to have 100 nm sizes with good polydispersity index and encapsulation efficiency of 91% for lactoferrin as well as sustained release of lactoferrin during 24 h. Transferosomal lactoferrin efficacy was evaluated by MTT assay. It was seen that the viral inhibitory concentration (IC50) of transfersomal lactoferrin has been significantly improved to nearly one tenth in comparison to free lactoferrin.

Noninvasive Transdermal Delivery System of Lidocaine Using an Acoustic Droplet-Vaporization Based Wearable Patch.

Current technologies for managing acute and chronic pain have focused on reducing the time required for achieving high therapeutic efficiency. Herein a wearable transdermal patch is introduced, employing an acoustic droplet vaporization (ADV) methodology, as an effective noninvasive transdermal platform, for a fast local delivery of the anesthetic agent lidocaine. The skin-worn patch consists of a flexible drug reservoir containing hundreds of micropores loaded with lidocaine, and mixed with the perfluorocarbon (PFC) emulsion. The ultrasound-triggered vaporization of the PFC emulsion provides the necessary force to breach dermal barriers. The drug release kinetics of our model was investigated by measuring the amount of lidocaine that passed through phantom tissue and pigskin barriers. The ADV platform increases the payload skin penetration resulting in shorter treatment times compared to passive diffusion or ultrasound alone, holding considerable promise for addressing the delayed therapeutic action and slow pain relief of existing delivery protocols. It is envisioned that the integration of ADV-based transdermal devices could be expanded to the depth-dependent delivery of other pain management, vaccines, and gene therapy modalities.

Hyaluronate-Gold Nanorod/DR5 Antibody Complex for Noninvasive Theranosis of Skin Cancer.

Noninvasive transdermal delivery is a promising method with distinct advantages including patient compliance over other delivery routes. Here, hyaluronate-gold nanorod/death receptor 5 antibody (HA-AuNR/DR5 Ab) complex was developed for transdermal theranosis of skin cancer. The successful formation of the complex was corroborated by 1H nuclear magnetic resonance, UV-vis spectroscopy, dynamic light scattering, zeta potential, and transmission electron microscopy. In vitro biological activity of the complex was verified by ELISA and MTT assay using HCT116 cancer cells. In addition, in vivo photoacoustic imaging and two-photon microscopy clearly visualized the transdermal delivery of HA-AuNR/DR5 Ab complex through the inevitable barrier of stratum corneum in the skin. Furthermore, in vivo antitumor effect on skin cancer model mice was confirmed from statistically significant decrease of tumor-reflecting luciferase expression levels and apoptotic signals in terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Taken together, we could confirm the feasibility of HA-AuNR/DR5 Ab complex as a novel theranostic platform for noninvasive transdermal treatment of skin cancers.

Combination of nanoparticles with photothermal effects and phase-change material enhances the non-invasive transdermal delivery of drugs

We describe a promising non-invasive transdermal delivery system comprising block copolymer composite micelles that contained a phase-change material (PCM), photothermal Au nanoparticles (AuNPs), and hydrophobic drugs in the core. To minimize cell toxicity, we developed block copolymer micelles with a poly(ɛ-caprolactone) (PCL) biodegradable core and a hyperbranched polyglycol (hbPG) shell. The hbPG block formed micelles at a low-molecular-weight fraction of a low-molecular-weight block copolymer. The composite micelles showed excellent biocompatibility with cell viability at high concentrations. Visible light irradiation (λ=520nm) of the composite micelles induced the photothermal effects of the AuNPs and melting of the PCM (lauric acid); hence, the drugs were released along with the PCM liquid. The release rate was controlled by the light intensity. Based on in vitro and in vivo skin penetration studies, the skin permeability of the drug remarkably improved under mild light irradiation (18J/cm2) that was much lower than the dose that causes skin damage.

Novel Self-assembled, Gel-core Hyaluosomes for Non-invasive Management of Osteoarthritis: In-vitro Optimization, Ex-vivo and In-vivo Permeation.

Hyaluronic acid (HA) is an imperative biomaterial with desirable rheological properties to alleviate symptoms of osteoarthritis. Nevertheless, scantly percutaeous permeation of this macromolecule handicaps its effective use for orthopedics and triggers intra-articular injection as the only surrogate. This study presents novel self-assembeld HA-based gel core elastic nanovesicles, (hyaluosomes; GC-HS), for non-invasive transdermal delivery of HA. GC-HS were prepared with 1% HA using simple film hydration technique. Their size, zeta potential, percentage entrapment efficiency (% EE), elasticity, and ex-vivo transdermal permeation were evaluated compared to conventional liposomes CL. Structure elucidation of the formed novel system was performed using light, polarizing and transmission electron microscopy. In-vivo permeation of GC-HS through knee joints of female Sprague Dawley rats was compared to CL and HA alone. GC-HS showed nanosize (232.8 ± 7.2), high negative zeta potential (-45.1 ± 8.3) and higher elasticity (size alteration 5.43%) compared to CL. This novel system has self-penetration enhancing properties compared to CL and plain gel. GC-HS showed self-assembled properties and high physically stable for at least 6 months at 4°C. Ex-vivo permeation of HS was significantly higher than CL and plain HA gel alone. In-vivo study exhibited significant six folds increase in transdermal permeation of HA to knee joints from GC-HS compared to plain HA gel. Novel GC-HS are promising nanogels for topical management of osteoarthritis surrogating the need for intra-articular injection.

Finite element static displacement optimization of 20–100 kHz flexural transducers for fully portable ultrasound applicator

This paper focuses on the development of a finite-element model and subsequent stationary analysis performed to optimize individual flexural piezoelectric elements for operation in the frequency range of 20–100kHz. These elements form the basic building blocks of a viable, un-tethered, and portable ultrasound applicator that can produce intensities on the order of 100mW/cm2 spatial-peak temporal-peak (ISPTP) with minimum (on the order of 15V) excitation voltage. The ultrasound applicator can be constructed with different numbers of individual transducer elements and different geometries such that its footprint or active area is adjustable.The primary motivation behind this research was to develop a tether-free, battery operated, fully portable ultrasound applicator for therapeutic applications such as wound healing and non-invasive transdermal delivery of both naked and encapsulated drugs.It is shown that careful selection of the components determining applicator architecture allows the displacement amplitude to be maximized for a specific frequency of operation. The work described here used the finite-element analysis software COMSOL to identify the geometry and material properties that permit the applicator’s design to be optimized. By minimizing the excitation voltage required to achieve the desired output (100mW/cm2ISPTP) the power source (rechargeable Li-Polymer batteries) size may be reduced permitting both the electronics and ultrasound applicator to fit in a wearable housing [1].

Optimization of un-tethered, low voltage, 20–100 kHz flexural transducers for biomedical ultrasonics applications

This paper describes optimization of un-tethered, low voltage, 20–100kHz flexural transducers for biomedical ultrasonics applications. The goal of this work was to design a fully wearable, low weight (<100g), battery operated, piezoelectric ultrasound applicator providing maximum output pressure amplitude at the minimum excitation voltage.Such implementation of ultrasound applicators that can operate at the excitation voltages on the order of only 10–25V is needed in view of the emerging evidence that spatial-peak temporal-peak ultrasound intensity (ISPTP) on the order of 100mW/cm2 delivered at frequencies below 100kHz can have beneficial therapeutic effects. The beneficial therapeutic applications include wound management of chronic ulcers and non-invasive transdermal delivery of insulin and liposome encapsulated drugs.The early prototypes of the 20 and 100kHz applicators were optimized using the maximum electrical power transfer theorem, which required a punctilious analysis of the complex impedance of the piezoelectric disks mounted in appropriately shaped metal housings.In the implementation tested, the optimized ultrasound transducer applicators were driven by portable, customized electronics, which controlled the excitation voltage amplitude and facilitated operation in continuous wave (CW) or pulsed mode with adjustable (10–90%) duty cycle. The driver unit was powered by remotely located rechargeable lithium (Li) polymer batteries. This was done to further minimize the weight of the applicator unit making it wearable. With DC voltage of approximately 15V the prototypes were capable of delivering pressure amplitudes of about 55kPa or 100mW/cm2 (ISPTP). This level of acoustic output was chosen as it is considered safe and side effects free, even at prolonged exposure.

Effect of microneedle on the pharmacokinetics of ketoprofen from its transdermal formulations

Non-invasive transdermal delivery using microneedle arrays was recently introduced to deliver a variety of large and hydrophilic compounds into the skin, including proteins and DNA. In this study, a microneedle array was applied to the delivery of a hydrophobic drug, ketoprofen, to determine if transdermal delivery in rats can be improved without the need for permeation enhancers. The ability of a microneedle to increase the skin permeability of ketoprofen was tested using the following procedure. A microneedle array was inserted into the lower back skin of a rat using a clip for 10 min. Subsequently, 24 mg/kg of a ketoprofen gel was loaded on the same site where the microneedle had been applied. Simultaneously, the microneedle was coated with 24 mg/kg of a ketoprofen gel, and inserted into the skin using a clip for 10 min. As a negative control experiment, only 24 mg/kg of the ketoprofen gel was applied to the shaved lower back of a rat. Blood samples were taken at the indicated times. The plasma concentration (Cp) was obtained as a function of time (t), and the pharmacokinetic parameters were calculated using the BE program. The group loaded with the microneedle coated with ketoprofen gel showed a 1.86-fold and 2.86-fold increase in the AUC and Cmax compared with the ketoprofen gel alone group. These results suggest that a microneedle can be an ideal tool for transdermal delivery products.

Structure–permeation relationships for the non-invasive transdermal delivery of cationic peptides by iontophoresis

Transdermal iontophoresis enables the controlled, non-invasive administration of peptide therapeutics. The aims of this study were (i) to evaluate the effect of amino acid sequence and the spatial distribution of peptide physicochemical properties on electrotransport, and (ii) to develop a quantitative model to predict peptide transport rates. Experimental results showed that the distribution of molecular properties over the peptide surface significantly affected iontophoretic delivery: different arrangements of the same residues resulted in different transport behavior. Computational studies generated three-dimensional quantitative structure–permeation relationships (3D-QSPR) based on 3D descriptors. The model predicted that iontophoresis was favored by peptide hydrophilicity but hindered by voluminous, localized hydrophobicity. Molecular characteristics that favor electrotransport are the converse of those required for passive diffusion across biological membranes. The data represent the first analysis of peptide electrotransport in terms of the spatial distribution of molecular properties and provide insight into the ab initio prediction of transdermal iontophoretic peptide delivery.