A novel thermo-mechanical system enhanced transdermal delivery of hydrophilic active agents by fractional ablation

Percutaneous delivery of liquid tetracycline using a thermal resurfacing drug delivery system for the treatment of festoons

OBJECTIVES

To examine the effects of percutaneous tetracycline delivery to the malar area using a thermomechanical device (Tixel) in patients suffering from festoons.

METHODS

This retrospective study included patients who underwent combination treatment with a thermomechanical device (Tixel) followed by application of topical tetracycline 1% at two private clinics between 2019 and 2023. Demographic and medical data, treatment parameters along with before and after treatment photographs were retrieved retrospectively. All patients were asked to answer a questionnaire, assessing self-reported pre and posttreatment disturbance, patient global impression of change (PGIC) score, overall satisfaction with treatment, and the onset and duration of treatment effect. Finally, three masked reviewers evaluated and graded the severity of before and after treatment photographs.

RESULTS

Twenty healthy patients received the combination treatment. The mean age was 59.4 ± 8.2 years (range: 45-72 years), and 90.0% (n = 18) were female. The number of treatment sessions per patient ranged from 2 to 8, mean of 5.0 ± 1.9, performed at 5.4 ± 1.2-week intervals. The masked reviewers' grading scores demonstrated a significant improvement (2.81 ± 1.3 before vs. 1.6 ± 1.1 after, p < 0.001). The self-reported disturbance caused by the festoons improved significantly as well (4.7 ± 0.98 vs. 1.7 ± 1.1, p < 0.001). On the PGIC score, 85% (17/20) reported moderate (grade 5) to significant (grade 7) improvement of symptoms and life quality after treatment. Improvement onset was reported to occur 11.2 ± 6.6 days after the first treatment (range 2-30 days), and 90% (18/20) of the patients reported improvement lasting at least 4 months after completion of the second treatment.

CONCLUSIONS

Topical tetracycline application following Tixel treatment induced significant improvement in patient with festoons.

Development of a Microfluidic Formatted Ultrasound-Controlled Monodisperse Lipid Vesicles' Hydrogel Dressing Combined with Ultrasound for Transdermal Drug Delivery System

Transdermal drug delivery system (TDDS) has attracted much attention in the pharmaceutical technology area. However, the current methods are difficult to ensure penetration efficiency, controllability, and safety in the dermis, so its widespread clinical use has been limited. This work proposes an ultrasound-controlled monodisperse lipid vesicles (U-CMLVs) hydrogel dressing, which combines with ultrasound to form TDDS. Using microfluidic technology, prepare size controllable U-CMLVs with high drug encapsulation efficiency and quantitative encapsulation of ultrasonic response materials, and even uniform mix them with hydrogel to prepare the required thickness of dressings. The high encapsulation efficiency can ensure sufficient dosage of the drugs and further realize the control of ultrasonic response through quantitative encapsulation of ultrasound-responsive materials. Using high frequency (5 MHz, 0.4 W cm-2 ) and low frequency (60 kHz, 1 W cm-2 ) ultrasound to control the movement and rupture of U-CMLVs, the contents not only penetrate the stratum corneum into the epidermis but also break through the bottleneck of penetration efficiency, and deep into the dermis. These findings provide the groundwork for deep, controllable, efficient, and safe drug delivery through TDDS and lay a foundation for further expanding its application.

Research progress of physical transdermal enhancement techniques in tumor therapy

The advancement and popularity of transdermal drug delivery (TDD) based on the physical transdermal enhancement technique (PTET) has opened a new paradigm for local tumor treatment. The drug can be directly delivered to the tumor site through the skin, thus avoiding the toxic side effects caused by the first-pass effect and achieving high patient compliance. Further development of PTETs has provided many options for antitumor drugs and laid the foundation for future applications of wearable closed-loop targeting drug delivery systems. In this highlight, the different types of PTETs and related mechanisms, and applications of PTET-related tumor detection and therapy are highlighted. According to their type and characteristics, PTETs are categorized as follows: (1) iontophoresis, (2) electroporation, (3) ultrasound, (4) thermal ablation, and (5) microneedles. PTET-related applications in the local treatment of tumors are categorized as follows: (1) melanoma, (2) breast tumor, (3) squamous cell carcinoma, (4) cervical tumor, and (5) others. The challenges and future prospects of existing PTETs are also discussed. This highlight will provide guidance for the design of PTET-based wearable closed-loop targeting drug delivery systems and personalized therapy for tumors.

Derivatives of L-Ascorbic Acid in Emulgel: Development and Comprehensive Evaluation of the Topical Delivery System

The dual controlled release of emulgels makes them efficient drug delivery systems of increasing interest. The framework of this study was to incorporate selected L-ascorbic acid derivatives into emulgels. From the formulated emulgels, the release profiles of actives were evaluated considering their different polarities and concentrations, and consequently their effectiveness on the skin via a long-term in vivo study that lasted for 30 days was determined. Skin effects were assessed by measuring the electrical capacitance of the stratum corneum (EC), trans-epidermal water loss (TEWL), melanin index (MI) and skin pH. In addition, the sensory and textural properties of emulgel formulations were compared with each other. The changes in the rate of the release of the L-ascorbic acid derivatives were monitored using the Franz diffusion cells. The obtained data were statistically significant, and indicated an increase in the degree of hydration of the skin and skin whitening potential, while no significant changes in TEWL and pH values were detected. The consistency, firmness and stickiness of the emulgels were estimated by volunteers applying the established sensory evaluation protocol. In addition, it was revealed that the difference in hydrophilic/lipophilic properties of L-ascorbic acid derivatives influenced their release profiles without changing their textural characteristics. Therefore, this study highlighted emulgels as L-ascorbic acid suitable carrier systems and one of the promising candidates as novel drug delivery systems.

The effect of thermo-mechanical device (Tixel) treatment on evaporative dry eye disease - A pilot prospective clinical trial

PURPOSE

To examine the effects of treatment with a thermomechanical skin device to the eyelid area on the clinical signs and symptoms of patients who suffer from dry eye disease (DED) secondary to meibomian gland dysfunction (MGD).

METHODS

Forty patients aged 45 years or older with DED due to MGD were recruited. Both eyes (n = 80) of each patient received three treatments with the Tixel device (Novoxel®, Israel), with each treatment separated by a 2-week period. Treatment was applied across the upper and lower eyelids, with the same intensity, tip protrusion distance, and contact duration. Two additional follow-up visits were performed at 2-week intervals after treatment cessation. DED status was evaluated during each visit via SPEED II questionnaire, tear break-up time (TBUT), corneal staining score (CSS), MGD score, and frequency of lubricant use. Visual acuity (VA) was recorded during first and last visits.

RESULTS

Mean age was 64.3 ± 12.4 years and 72.5 % (n = 29) were female. 45 % (n = 18) had a history of blepharitis, 12.5 % (n = 5) had chalazia, and 17.5 % (n = 7) suffered from allergic conjunctivitis. Mean follow-up time was 2.1 ± 0.6 months. Comparing the first and last visits, all parameters showed significant improvement after Tixel treatment: mean SPEED II scores (16.5 ± 5.9 to 11.8 ± 6.7, p < 0.001), CSS (2.0 ± 1.3 to 0.5 ± 0.9, p < 0.001), TBUT (2.7 ± 0.8 s to 6.5 ± 2.2 s, p < 0.001), MGD score (2.7 ± 0.5 to 1.2 ± 0.4, p < 0.001), and rate of lubricant use (3.4 ± 2.4 per day to 1.9 ± 2.0, p < 0.001). VA also improved (0.10 ± 0.11 logMAR to 0.08 ± 0.10 logMAR, p < 0.05). No major side effects were observed.

CONCLUSIONS

In this pilot study Tixel treatment induced significant improvement of signs and symptoms among patients with DED due to MGD. Benefits persisted for at least one month. Further randomized controlled double-blinded studies are needed.

Evaluation of Device-Based Cutaneous Channels Using Optical Coherence Tomography: Impact for Topical Drug Delivery

BACKGROUND

Topical medications play a large role in the management of cutaneous diseases, but penetration is limited. Device-assisted drug delivery using mechanical destruction, lasers, and other energy-based modalities can increase penetration and absorption through creation of transcutaneous channels.

OBJECTIVE

To examine real-time, in vivo cutaneous changes in response to various devices used to improve topical drug delivery through optical coherence tomography (OCT) imaging.

METHODS AND MATERIALS

Treatment was performed with 8 medical devices, including mechanical destruction, lasers, and other energy-based modalities. Optical coherence tomography was used for real-time, noninvasive, in vivo imaging.

RESULTS

Using OCT, microneedling and radiofrequency microneedling demonstrated no cutaneous channels. Both low-energy, low-density, fractional nonablative lasers produced transient channels, which closed within hours. The fractional nonablative 1,927-nm thulium fiber and 1,550-nm erbium fiber lasers created channels with epidermal debris within, which were still closing at 24 hours. The fractional thermomechanical ablative device and the fractional ablative CO2 laser produced channels that were still open at 24 hours. CO2 laser channels had thick rims of coagulated tissue and remained open for longer.

CONCLUSION

Demonstrable differences among the devices were seen, and only some can produce observable channels, the characteristics of which vary with each technology.

Efficacy and safety of thermomechanical fractional injury-assisted corticosteroid delivery versus intralesional corticosteroid injection for the treatment of hypertrophic scars: A randomized split-scar trial

BACKGROUND

Disruption of the natural skin barrier in a controlled manner may be used to deliver drugs that enhance scar resolution.

OBJECTIVE

To compare the efficacy and safety of thermomechanical fractional injury (TMFI)-assisted topical corticosteroid delivery with corticosteroid injection in the treatment of hypertrophic scar (HTS).

MATERIALS AND METHODS

This was a randomized, split-scar, double-blinded study. Twenty-one subjects with HTS on the abdomen received five split-scar treatments of TMFI + Steroid and steroid injection alone. Changes in scar thickness, scar volume, and Vancouver Scar Scale (VSS) were analyzed. Patient self-assessment, VAS scores, and adverse effects were also evaluated.

RESULTS

Scar thickness, volume, and VSS scores of both segments improved significantly compared to baseline. On every follow-up visit, there were no significant differences in mean scar thickness reduction between the two treatment groups except at the 6-month follow-up where the mean scar thickness reduction of the steroid injection segment was significantly lower than that of the TMFI + Steroid segment (95% confidence interval [CI], 0.09-0.35; p = 0.002). Scar volume, VSS scores, and patient self-assessment also showed no significant differences between both segments on all visits. The steroid injection segment was significantly more painful than the TMFI + Steroid segment (95% CI, -2.16 to -1.29; p < 0.001). Adverse effects of skin atrophy, telangiectasia, and post-inflammatory hyperpigmentation were noted in the steroid injection segment, while no adverse effects were observed at the TMFI + Steroid segment.

CONCLUSIONS

TMFI-assisted topical corticosteroid delivery is an effective treatment for HTS with a lower risk of adverse effects compared with corticosteroid injection.

Thermo-vibrational analyses of skin tissue subjected to laser heating source in thermal therapy

Laser-induced thermal therapy, due to its applications in various clinical treatments, has become an efficient alternative, especially for skin ablation. In this work, the two-dimensional thermomechanical response of skin tissue subjected to different types of thermal loading is investigated. Considering the thermoelastic coupling term, the two-dimensional differential equation of heat conduction in the skin tissue based on the Cattaneo–Vernotte heat conduction law is presented. The two-dimensional differential equation of the tissue displacement coupled with the two-dimensional hyperbolic heat conduction equation in the tissue is solved simultaneously to analyze the thermal and mechanical response of the skin tissue. The existence of mixed complicated boundary conditions makes the problem so complex and intricate. The Galerkin-based reduced-order model has been utilized to solve the two-sided coupled differential equations of vibration and heat transfer in the tissue with accompanying complicated boundary conditions. The effect of various types of heating sources such as thermal shock, single and repetitive pulses, repeating sequence stairs, ramp-type, and harmonic-type heating, on the thermomechanical response of the tissue is investigated. The temperature distribution in the tissue along depth and radial direction is also presented. The transient temperature and displacement response of tissue considering different relaxation times are studied, and the results are discussed in detail.

Treatment of periorbital wrinkles using thermo-mechanical fractional injury therapy versus fractional non-ablative 1565 nm laser: A comparative prospective, randomized, double-arm, controlled study

BACKGROUND

Non-ablative fractional laser is an effective modality for the treatment of periorbital wrinkling, one of the earliest signs of skin aging. Thermo-mechanical fractional injury (TMFI) therapy (Tixel®, Novoxel®, Israel) is an innovative technology that is now being used for facial skin rejuvenation. Our study compares the clinical results, side effects, and downtime profile between TMFI treatment and non-ablative fractional 1565 nm laser (ResurFX®, Luminis, Israel).

METHODS

This was a prospective study of 68 patients (64 women, 4 men) with skin types I-VI in two medical centers (34 from Israel, 34 from the USA) that were randomized to receive either TMFI or NAFL treatment for periorbital wrinkling. Patients received 3-5 treatments, 3-5 weeks apart. Six months after the last treatment, the change in Fitzpatrick Wrinkling Classification System (FWCS) was calculated by three non-involved physicians and compared to pretreatment results. Side effects and downtime profiles were assessed in each group (including VAS pain assessment, time required to refrain from work and social activity, and time required for the resolution of redness, edema, and crusts.) RESULTS: A moderate improvement in periorbital wrinkling was demonstrated in both groups, with an average improvement of 1.6 ± 0.6 in FWCS in the TMFI group and an average improvement of 1.7 ± 0.8 in the NAFL group (p < 0.001). Postprocedural VAS score was 5.86 ± 2.3 in the NAFL group and 4.01 ± 2.6 in the Tixel® group. Approximately 80% of subjects returned to both work and social activities two days postprocedure. Crusts were reported by 52% of patients in the TMFI group, compared to 16% of patients in the NAFL group more than 48 hours postprocedure (p < 0.05). There were no statistically significant differences in the other parameters between the two groups.

CONCLUSION

TMFI is an effective and safe modality for the treatment of periorbital wrinkling, with comparable results to the 1565 nm NAFL.

Thermo-Mechanical Fractional Injury Enhances Skin Surface- and Epidermis- Protoporphyrin IX Fluorescence: Comparison of 5-Aminolevulinic Acid in Cream and Gel Vehicles

BACKGROUND AND OBJECTIVES

Thermo-mechanical fractional injury (TMFI) impacts the skin barrier and may increase cutaneous drug uptake. This study investigated the potential of TMFI in combination with 5-aminolevulinic acid (ALA) cream and gel formulations to enhance Protoporphyrin IX (PpIX) fluorescence at the skin surface and in the skin.

STUDY DESIGN/MATERIALS AND METHODS

In healthy volunteers (n = 12) a total of 144 test areas were demarcated on the upper back. Test areas were randomized to (i) TMFI (6 milliseconds, 400 µm at a single pass) or no pretreatment and (ii) 20% ALA in cream or gel formulations. Skin surface PpIX fluorescence was quantified by PpIX fluorescence photography and photometry in 30-minute intervals until 3 hours. PpIX fluorescence microscopy quantified separate PpIX fluorescence in the epidermis, and in superficial-, mid-, and deep- dermis from punch biopsies sampled after 3 hours of ALA incubation. Local skin reactions (LSR) and pain intensities (numerical rating scale 0-10) were evaluated immediately, at 3 hours and 14 days after the intervention.

RESULTS

TMFI exposure before photosensitizer application significantly increased skin surface PpIX fluorescence, both for ALA cream (TMFI-ALA-cream 7848 arbitrary units [AU] vs. ALA-cream 5441 AU, 3 hours, P < 0.001) and ALA gel (TMFI + ALA-gel 4591 AU vs. ALA-gel 3723 AU, 3 hours, P < 0.001). The TMFI-mediated increase in PpIX fluorescence was similar for ALA-cream and -gel formulations (P = 0.470) at the skin surface. In the epidermis, PpIX fluorescence intensities increased from combination treatment with TMFI and ALA-cream (TMFI + ALA-cream 421 AU vs. ALA-cream 293 AU, P = 0.034) but not from combination with TMFI and ALA-gel (TMI + ALA-gel 264 AU vs. ALA-gel 261 AU, P = 0.791). Dermal fluorescence intensities (superficial-, mid-, or deep dermis) were unaffected by TMFI pretreatment in both ALA-cream and ALA-gel exposed skin (P = 0.339). ALA-cream generally induced higher PpIX fluorescence intensities than ALA-gel (skin surface P < 0.001 and epidermis P < 0.03). TMFI induced low pain intensities (median 3) and mild LSR that were resolved at 14 days follow-up.

CONCLUSION

Given the present study design, TMFI, in combination with the standardized application of 20% ALA cream and gel formulations, significantly enhanced skin surface PpIX fluorescence compared to no pretreatment. Additionally, TMFI increased epidermal PpIX fluorescence combined with 20% ALA cream vehicle. Thus, TMFI pretreatment and formulation characteristics exert influence on PpIX fluorescence intensities in normal skin. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Enhancement of skin permeability with thermal ablation techniques: concept to commercial products

Traditionally, the skin is considered as a protective barrier which acts as a highly impermeable region of the human body. But in recent times, it is recognized as a specialized organ that aids in the delivery of a wide range of drug molecules into the skin (intradermal drug delivery) and across the skin into systemic circulation (transdermal drug delivery, TDD). The bioavailability of a drug administered transdermally can be improved by several penetration enhancement techniques, which are broadly classified into chemical and physical techniques. Application of mentioned techniques together with efforts of various scientific and innovative companies had made TDD a multibillion dollar market and an average of 2.6 new transdermal drugs are being approved each year. Out of various techniques, the thermal ablation techniques involving chemicals, heating elements, lasers, and radiofrequency (RF) are proved to be more effective in terms of delivering the drug across the skin by disrupting the stratum corneum (SC). The reason behind it is that the thermal ablation technique resulted in improved bioavailability, quick treatment and fast recovery of the SC, and more importantly it does not cause any damage to underlying dermis layer. This review article mainly discussed about various thermal ablation techniques with commercial products and patents in each classes, and their safety aspects. This review also briefly presented anatomy of the skin, penetration pathways across the skin, and different generations of TDD.

Enhanced Percutaneous Delivery of Beta-Blockers Using Thermal Resurfacing Drug Delivery System for Topical Treatment of Infantile Hemangiomas

<b><i>Background:</i></b> Infantile hemangiomas (IHs) are the most common vascular tumors in children. In the past few years, topical beta-blockers (bBs) have been reported to be an effective treatment of superficial IHs. <b><i>Objective:</i></b> We sought to evaluate the clinical effectiveness and safety profile of enhanced percutaneous delivery of bBs for the treatment of IH. <b><i>Methods:</i></b> A retrospective study of all cases of IHs treated with enhanced percutaneous delivery of bBs between 2018 and 2019 was performed. Epidemiologic, clinical, and treatment data, including effectiveness score and safety, were reviewed. <b><i>Results:</i></b> The study included 11 patients with a total of 11 IHs. Of the total number of IHs, 7 (63.7%) showed a good response to treatment and 4 (36.3%) had a partial response; thus all patients (100%) had good or partial response to treatment. No systemic or local adverse effects were reported. <b><i>Limitations:</i></b> This is an uncontrolled retrospective study. <b><i>Conclusion:</i></b> Enhanced percutaneous delivery of bBs is a safe and efficient topical therapy for IH.

A New Method for Percutaneous Drug Delivery by Thermo-Mechanical Fractional Injury

BACKGROUND AND OBJECTIVES

Percutaneous drug delivery (PDD) is a means of increasing the uptake of topically applied agents into the skin. Successful delivery of a photosensitizer into the skin is an important factor for effective photodynamic therapy. To evaluate the efficacy of pretreatment by thermomechanical fractional injury (TMFI) (Tixel®, Novoxel®, Israel) at low-energy settings in increasing the permeability of the skin to a known hydrophilic-photosensitizer medication, 5-amino-levulinic-acid hydrochloride (ALA) in compounded 20% ALA gel. To compare the effect of TMFI on ALA permeation into the skin in compounded gel to three commercial photosensitizing medications in different vehicles: ALA microemulsion gel, methyl-amino-levulinic-acid hydrochloride (MAL) cream, and ALA hydroalcoholic solution.

STUDY DESIGN/MATERIALS AND METHODS

Five healthy subjects were treated in two separate experiments and on a total of 136 test sites, with four topical photosensitizer preparations as follows: compounded 20% ALA gel prepared in a good manufacturing practice (GMP)-certified pharmacy (Super-Pharm Professional, Israel), 10% ALA microemulsion gel (Ameluz®, Biofrontera Bioscience GmbH, Leverkusen, Germany), 16.8% MAL cream (Metvix®, Galderma, Lausanne, Switzerland), and 20% ALA hydroalcoholic solution (Levulan Kerastick®, DUSA Pharmaceuticals, Inc., Wilmington, MA, USA). The dermal sites were pretreated by Tixel® (Novoxel® Ltd., Israel) prior to topical drug application. One site was untreated to serve as control. Protoporphyrin IX (PpIX) fluorescence intensity readouts were taken immediately and 1, 2, 3, 4, and 5 hours posttreatment.

RESULTS

The highest average PpIX fluorescence intensity measurements were obtained for the compounded 20% ALA gel following pre-treatment by TMFI at 6 milliseconds pulse duration. After 2 and 3 hours, TMFI-treated sites exhibited an increased hourly rate in readouts of FluoDerm units, which were 156-176% higher than the control rates (P ≤ 0.004). TMFI pre-treatment did not enhance the percutaneous permeation of either ALA or MAL following the microemulsion gel, hydroalcoholic solution, and cream applications.

CONCLUSIONS

Pretreatment with low-energy TMFI at a pulse duration of 6 milliseconds increased the percutaneous permeation of ALA linearly over the first 5 hours from application when the compounded 20% ALA gel was used. Formulation characteristics have substantial influence on the ability of TMFI pretreatment to significantly increase the percutaneous permeation of ALA and MAL. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Ascorbic acid derivative-loaded modified aspasomes: formulation, in vitro, ex vivo and clinical evaluation for melasma treatment

Vitamin C (L-Ascorbic acid) has many favourable effects on the skin such as antioxidant, anti-aging and whitening effects. Its instability and low permeability limit its pharmaceutical use in cosmetic and dermatological products. Instead, Mg ascorbyl phosphate (MAP), an ascorbic acid derivative, has the same effect with higher stability is being used. In this work, a vesicular system, aspasomes, containing MAP was developed and evaluated. Aspasomes are multilayered vesicles formed by amphiphiles molecules, Ascorbyl palmitate (ASP), in combination with cholesterol and charged lipids for drug encapsulation. Here, we investigated the use of lecithin instead of the charged lipid dicetyl phosphate for aspasomes development. Nine formulations were prepared and evaluated for their entrapment efficiency, particle size, polydispersity index (PDI) and zeta potential. Their entrapment efficiency ranged from 33.00 ± 2.27 to 95.18 ± 1.06, while their particle size was from 373.34 ± 60.85 to 464.37 ± 93.46 nm with acceptable PDI (from 0.212 ± 0.068 to 0.351 ± 0.061) and zeta potential (from -37.52 ± 2.42 to -50.36 ± 1.82). Three formulations were selected and evaluated for their drug release, permeation and retention into skin. One formulation was selected to be formulated as aspasomal topical cream and gel. The aspasomal cream was found to have enhanced drug permeation and skin retention over the aspasomal gel as well as the aspasomes formulation. MAP aspasomal cream was evaluated clinically as an effective treatment for melasma against 15% trichloroacetic acid (TCA) and the results recorded that the aspasomal cream showed the greatest degree of improvement regarding the hemi-MASI scores with 35% of patients rating it as excellent treatment. The study showed that MAP aspasomal cream can be considered a novel treatment of melasma which is free of side effects. Its efficacy as a monotherapy is superior to that of chemical peeling using 15% TCA.

Microcapsule-embedded hydrogel patches for ultrasound responsive and enhanced transdermal delivery of diclofenac sodium

Transdermal delivery of diclofenac sodium (DS) has drawn much attention for the advantages of avoiding first-pass metabolism, reduced systemic toxicity and better patient compliance, but the successful translation of reported transdermal drug delivery systems (TDDSs) is still limited by poor skin permeability and uncontrollable drug release. Herein, we designed and fabricated a novel ultrasound responsive TDDS by embedding DS-loaded polyester microcapsules into a hydrogel patch based on four-armed poly(ethylene glycol). The rational design endows the microcapsule-embedded hydrogel patch with good biocompatibility, excellent skin-adhesion properties and well-controlled ultrasound responsive release behavior. More importantly, by employing ultrasound as a simultaneous trigger of drug release and efficient penetration enhancer, the encapsulated drug could be released and pass through the skin barrier rapidly under ultrasound, while without the action of ultrasound, a negligible amount of drug was released and penetrated into the subcutaneous tissues in ex vivo and in vivo transdermal drug release experiments, indicating that improved and controllable transdermal delivery of DS was achieved. Our work demonstrated that the microcapsule-embedded hydrogel patch may be a promising candidate as an ultrasound responsive and enhanced TDDS of DS for treating diseases such as arthritis and topical soft tissue injuries.

The toxic edge-A novel treatment for refractory erythema and flushing of rosacea

PURPOSE

Rosacea is a common, chronic facial skin disease that affects the quality of life. Treatment of facial erythema with intradermal botulinum toxin injection has previously been reported. The primary objective of the study was the safety and efficacy of thermal decomposition of the stratum corneum using a novel non-laser thermomechanical system (Tixel, Novoxel, Israel) to increase skin permeability for Botulinum toxin in the treatment of facial flushing of rosacea.

METHODS

A retrospective review of16 patients aged 23-45 years with Fitzpatrick Skin Types II to IV and facial erythematotelangiectatic rosacea treated by Tixel followed by topical application of 100 U of abobotulinumtoxin. A standardized high-definition digital camera photographed the patients at baseline and 1, 3, and 6 months after the last treatment. Objective and subjective assessments of the patients were done via Mexameter, the Clinicians Erythema Assessment (CEA), and Patients self-assessment (PSA) scores and the dermatology life quality index (DLQI) validated instrument.

RESULTS

The average Maxameter, CEA, and PSA scores at 1, 3, and 6 months were significantly improved compared with baseline (all had a P-value <0.001). DLQI scores significantly improved with an average score of 18.6 at baseline at 6 months after treatment (P < 0.001). Self-rated patient satisfaction was high. There were no motor function side-effects or drooping.

CONCLUSION

Thermal breakage of the stratum corneum using the device to increase skin permeability for botulinum toxin type A in the treatment of facial flushing of rosacea seems both effective and safe. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.

Biomechano-Interactive Materials and Interfaces

The reciprocal mechanical interaction of engineered materials with biointerfaces have long been observed and exploited in biomedical applications. It contributes to the rise of biomechano-responsive materials and biomechano-stimulatory materials, constituting the biomechano-interactive interfaces. Here, endogenous and exogenous biomechanical stimuli available for mechanoresponsive interfaces are briefed and their mechanistic responses, including deformation and volume change, mechanomanipulation of physical and chemical bonds, dissociation of assemblies, and coupling with thermoresponsiveness are summarized. The mechanostimulatory materials, however, are capable of delivering mechanical cues, including stiffness, viscoelasticity, geometrical constraints, and mechanical loads, to modulate physiological and pathological behaviors of living tissues through the adaptive cellular mechanotransduction. The biomechano-interactive materials and interfaces are widely implemented in such fields as mechanotriggered therapeutics and diagnosis, adaptive biophysical sensors, biointegrated soft actuators, and mechanorobust tissue engineering, which have offered unprecedented opportunities for precision and personalized medicine. Pending challenges are also addressed to shed a light on future advances with respect to translational implementations.

Combined use of nanocarriers and physical methods for percutaneous penetration enhancement

Dermal and transdermal drug delivery (due to its non-invasiveness, avoidance of the first-pass metabolism, controlling the rate of drug input over a prolonged time, etc.) have gained significant acceptance. Several methods are employed to overcome the permeability barrier of the skin, improving drug penetration into/through skin. Among chemical penetration enhancement methods, nanocarriers have been extensively studied. When applied alone, nanocarriers mostly deliver drugs to skin and can be used to treat skin diseases. To achieve effective transdermal drug delivery, nanocarriers should be applied with physical methods, as they act synergistically in enhancing drug penetration. This review describes combined use of frequently used nanocarriers (liposomes, novel elastic vesicles, lipid-based and polymer-based nanoparticles and dendrimers) with the most efficient physical methods (microneedles, iontophoresis, ultrasound and electroporation) and demonstrates superiority of the combined use of nanocarriers and physical methods in drug penetration enhancement compared to their single use.

Nano-patterning of a stainless steel microneedle surface to improve the dip-coating efficiency of a DNA vaccine and its immune response

DNA vaccination with microneedles (MNs) into the skin represents a potential therapeutic approach for the clinical treatment of viral diseases as well as for intradermal genetic immunization. In this study, we investigated a DNA vaccination against the severe fever with thrombocytopenia syndrome virus (SFTSV) delivered by nano-patterned microneedles (nMNs) to improve the efficiency compared to a conventional MN vaccination. Because DNA vaccinations delivered by coated MNs have major disadvantages such as a poor coating efficiency and immunogenicity, additional excipients are necessary. Therefore, we developed nMNs to improve the affinity of stainless steel for plasmid DNA vaccinations. The results show that the nMNs have an improved DNA vaccine loading capacity because their surfaces have an increased hydrophilicity from the high surface/volume ratio. The cytocompatibility analysis also showed a higher cell proliferation when using the nMNs. Finally, the in vivo experiments with balb/c mice vaccinated with the SFTSV DNA vaccine-coated nMNs generated a higher level of cellular immune responses than that of the unmodified MNs.