Ablative fractional resurfacing in topical drug delivery: an update and outlook

Application of integrated skincare in medical aesthetics: A literature review

Integrated skincare combines clinically proven skincare products with professional medical aesthetics to provide a comprehensive solution for beauty pursuers. Studies have demonstrated that a combination of medical aesthetic procedures and maintenance therapies is more effective than either treatment alone. This review outlines the current applications of integrated skincare, including different regimens of energy-based aesthetic devices and active ingredients in cosmeceuticals or chemical peels. Additionally, the benefits and limitations of integrated skincare are discussed. Lastly, this review highlights the potential for improved satisfaction and long-term maintenance of the desired outcomes through appropriate integrated skincare procedures.

Fractional CO2 Laser for Transcutaneous Drug Delivery of Onabotulinum Toxin in Palmar Hyperhidrosis

BACKGROUND

Palmar hyperhidrosis is a common disorder of excessive sweating due to over-stimulation of cholinergic receptors on eccrine glands.

OBJECTIVE

To compare the efficacy of laser-assisted drug delivery of onabotulinum toxin A (BoNTA) and intradermal BoNTA injections in the management of palmar hyperhidrosis.

PATIENTS AND METHODS

This intrapatient comparative study was conducted on 30 adult patients with idiopathic palmar hyperhidrosis. The palms of the patients were divided into 2 groups. Group 1 was treated with intradermal injections of 50 units of BoNTA, whereas Group 2 was subjected to laser-assisted transcutaneous BoNTA delivery using fractional CO2 laser at different doses (25, 50, and 75 units). Each treatment modality was evaluated using the iodine starch test, hyperhidrosis disease severity scale, and gravimetric scoring.

RESULTS

Delivery of 75 units of BoNTA to the dermis on the right-sided palms assisted by fractional CO2 laser was clinically equivalent to 50 units of injection on the left side. Pain intensity was significantly higher on the injected side than on the other side.

CONCLUSION

Laser-assisted drug delivery of botulinum toxin can be considered an effective and safe alternative for treatment of palmar hyperhidrosis with minimal side effects and complications.

Topical methotrexate in dermatology: a review of the literature

Background: Systemic methotrexate (MTX) is a useful treatment for many dermatologic conditions, however, the risk of adverse events prevents its use in patients with minimal or localized disease. Topical application of MTX may be an option to avoid the systemic adverse effects of oral MTX.Objective: To assess what is known about the efficacy and safety of topical methotrexate.Methods: A search on Pubmed was conducted. There were no limits on publication date.Results: A total of 963 articles were discovered. Using our exclusion criteria, 916 articles were excluded; 47 articles were used for full text assessment. Topical MTX has been used primarily in psoriasis but also in mycosis fungoides, lymphomatoid papulosis, and oral precancerous lesions. Optimal delivery system and formulation for adequate penetration is still under investigation.Conclusion: The quality of evidence for the utility of topical methotrexate in psoriasis is good, however, for other dermatologic diseases, the quality is poor. Topical MTX with improved delivery methods may be a viable tool against certain localized dermatologic conditions for patients who do not tolerate oral MTX. Further double-blinded randomized controled studies are needed to substantiate the utility of topical methotrexate.

Advanced trends in protein and peptide drug delivery: a special emphasis on aquasomes and microneedles techniques

Proteins and peptides have a great potential as therapeutic agents; they have higher efficiency and lower toxicity, compared to chemical drugs. However, their oral bioavailability is very low; also, the transdermal peptide delivery faces absorption limitations. Accordingly, most of proteins and peptides are administered by parenteral route, but there are many problems associated with this route such as patient discomfort, especially for pediatric use. Thus, it is a great challenge to develop drug delivery systems for administration of proteins and peptides by routes other than parenteral one. This review provides an overview on recent advances adopted for protein and peptide drug delivery, focusing on oral and transdermal routes. This is followed by an emphasis on two recent approaches adopted as delivery systems for protein and peptide drugs, namely aquasomes and microneedles. Aquasomes are nanoparticles fabricated from ceramics developed to enhance proteins and peptides stability, providing an adequate residence time in circulation. It consists of ceramic core coated with poly hydroxyl oligomer, on which protein and peptide drug can be adsorbed. Aquasomes preparation, characterization, and application in protein and peptide drug delivery are discussed. Microneedles are promising transdermal approach; it involves creation of micron-sized pores in the skin for enhancing the drug delivery across the skin, as their length ranged between 150 and 1500 μm. Types of microneedles with different drug delivery mechanisms, characterization, and application in protein and peptide drug delivery are discussed. Graphical abstract.

Factors Affecting Depth of Penetration in Microneedling- and Laser-Assisted Drug Delivery: The Importance of Timing of Topical Application

BACKGROUND

Microneedling- and laser-assisted drug delivery are emerging techniques used to treat various conditions. However, key parameters affecting drug penetration remain unknown.

OBJECTIVE

This study aims to investigate the importance of timing of topical application, needle length, and device type for drug delivery.

MATERIALS AND METHODS

Skin harvested from cosmetic surgeries was treated with black ink applied before or after treatment with a microneedling pen (MP), roller, or fractional ablative CO2 laser, and incubated for different time intervals. Ink penetration was additionally tested using different needle lengths. Sandwich estimator was used for statistical analysis.

RESULTS

Ink applied before MP penetrated deeper compared to ink applied afterward at 1 and 3 hours, and roller microneedling in both the ink-before and -after scenarios at 1, 3, and 6 hours (p < .05). Microneedling demonstrated lateral extension of ink beyond microchannels with increased ink penetration over time. CO2 laser demonstrated ink localization within microthermal zones without time-dependent increases in depth after 30 minutes. Ink penetration increases by 0.06 mm per 1 mm increase in needle length.

CONCLUSION

Ink applied before MP results in the deepest penetration of ink. Microneedling offers unique advantages in transdermal delivery as its channels exhibit increasing penetration over time and lateral extension of product.

The Scar Bane, Without the Pain: A New Approach in the Treatment of Elevated Scars: Thermomechanical Delivery of Topical Triamcinolone Acetonide and 5-Fluorouracil

Introduction

Keloids are challenging to treat due to their inadequate response to treatment and high recurrence rate. Intralesional triamcinolone acetonide (TAC) injection with or without 5-fluorouracil (5FU) is considered the first-line treatment for keloids. Three significant disadvantages of intralesional injections are the pain associated with the procedure, the uneven topography, and epidermal atrophy. Fractionated ablative carbon dioxide (CO₂) laser-assisted drug delivery (LADD) of the topical solution can help facilitate transdermal drug delivery and shows promise in scar remodeling. This study examined the use of a thermomechanical device (Tixel, Novoxel) to facilitate the transdermal delivery of TAC and 5-FU in the treatment of keloid scars.

Methods

Seven patients each received eight topical thermal ablations, with one ablation performed every 2–3 weeks. TAC and 5FU were applied after each ablation. Outcomes were evaluated using the Vancouver Scar Scale (VSS), and pain was assessed using the Visual Analog Scale (VAS).

Results

Mean keloid VSS reduced from 8.6 ± 1.2 to 5 ± 2.7 after the eight treatments. Mean treatment pain VAS score was 2.4 ± 0.7. Patients rated their satisfaction level as moderate–high. No severe adverse reactions were noted.

Conclusion

Thermomechanical drug delivery of TAC and 5-FU is safe and effective. This is a promising option for the treatment of keloid scars, particularly in the pediatric population.

Individually coated microneedles for co-delivery of multiple compounds with different properties

Microneedle (MN) patches provide a simple method for delivery of drugs that might otherwise require hypodermic injection. Conventional MN patch fabrication methods typically can load only one or possibly multiple miscible agents with the same formulation on all MNs, which limits the combination and spatial distribution of drugs and formulations having different properties (such as solubility) in a single patch. In this study, we coated MNs individually instead of coating all MNs from the same formulation, making possible a patch where each individual MN is coated with different formulations and drugs. In this way, individually coated MN patches co-delivered multiple agents with different physicochemical characteristics (immiscible molecules, proteins, and nanoparticles) and in different spatial patterns in the skin. MN loading was adjusted by modifying the number of coating layers, and co-delivery of multiple agents was demonstrated in the porcine skin. We conclude that individually coating MNs enables co-delivery of multiple different compounds and formulations with needle-by-needle spatial control in the skin.

Fractional ablative carbon dioxide laser followed by topical sodium stibogluconate application: A treatment option for pediatric cutaneous leishmaniasis

BACKGROUND

Leishmaniasis is a protozoan zoonotic parasitic infection with cutaneous, mucocutaneous, and visceral manifestations. Israel is endemic for cutaneous leishmaniasis, which is a self-limited disease but is associated with scarring, which is often a source of psychological and social burden for patients. Scars can be especially devastating for children and teenagers. A wide range of physical and medical approaches is used to treat cutaneous leishmaniasis, among which intralesional injections of sodium stibogluconate rank among the most frequently used. Unfortunately, despite being effective, this therapeutic modality can be very painful. Fractional ablative laser creates a controlled mesh-like pattern of tissue ablation in the skin that promotes dermal remodeling and collagen production while at the same time facilitating enhanced delivery of topically applied medications.

METHODS

Patients were treated with fractional ablative carbon dioxide laser followed by immediate topical application of sodium stibogluconate. All children were diagnosed with cutaneous leishmaniasis prior to treatment initiation..

RESULTS

Ten children were treated. One leishmania tropica-positive girl failed to respond. The other nine patients achieved clinical cure and demonstrated good to excellent final cosmesis. Self-rated patient satisfaction and tolerance were high No adverse effects were observed or reported during treatment.

CONCLUSION

Fractional ablative carbon dioxide laser followed by topical sodium stibogluconate application appears to be a safe and promising treatment for cutaneous leishmaniasis infection in children. Future controlled studies are required to validate these findings and compare this technique with traditional approaches.

Comparative study of fractional CO2 laser and fractional CO2 laser-assisted drug delivery of topical steroid and topical vitamin C in macular amyloidosis

Macular amyloidosis (MA) represents a common variant of primary localized cutaneous amyloidosis. It has a characteristic female predominance; none of the treatment modalities described is either curative or uniformly effective in patients with macular amyloidosis. To determine the effect of fractional CO₂ laser in macular amyloidosis in comparison to fractional CO₂ laser-assisted drug delivery of topical steroids and topical vitamin C, the study includes 10 female patients with cutaneous macular amyloidosis aged between 20 and 62 years. Patients were treated with four sessions of fractional CO₂ laser with 4 weeks interval. Laser treatments were performed using fractional CO₂ laser with the following parameters (power 18 W, spacing 800 μm, dwell time 600 μs, stacking 3). The lesion is divided into three areas: area 1, treated by fractional laser only; area 2, treated by fractional laser followed by topical corticosteroid application under occlusion for 24 h; and area 3, treated by fractional laser followed by topical vitamin C serum application under occlusion for 24 h. All lesions were examined clinically and histologically before the therapy and 1 month after the end of the therapy to evaluate the degree of improvement. All treated areas show significant decrease in pigmentation score after treatment, significant drop in rippling (P value < 0.016), and improvement of lichenification; as regards the histological improvement, there was a significant decrease of the amyloid amount after treatment. As regards the amyloid amount, results show significant decrease in the amount of amyloid in all of the three treated areas. Area 2 reported the highest decrease in the amyloid amount followed by areas 1 and 3. One patient (10%) was highly satisfied by the treatment, 6 (60%) reported moderate degree of satisfaction, while only 3 (30%) reported mild satisfaction. Minimal complication occurred in the form of post-inflammatory hyperpigmentation in 1 patient. None of the patients suffered pain, ulceration, or infection. Fractional CO₂ alone can be used to improve the texture of macular amyloidosis. If used to assist the delivery of topical steroids and topical vitamin C, improvement can be highly increased.

Laser-Assisted Delivery to Treat Facial Scars

Treatment of facial scars is a multispecialty endeavor for optimal patient recovery. One new innovation helping in facial scar treatments are lasers. Fractional laser predictably (tunable) disrupts the barrier of the skin creating deep channels that allow the delivery of drug and cellular materials; this is called laser-assisted drug delivery (LAD). Without exception thus far, LAD has been found to enhance the local uptake of any drug or substance applied to the skin. These zones may be used postoperatively to deliver drugs and other substances to create an enhanced scar therapeutic response to drug or substance applied to the skin.

Semiconductor diode laser device adjuvanting intradermal vaccine

A brief exposure of skin to a low-power, non-tissue damaging laser light has been demonstrated to augment immune responses to intradermal vaccination. Both preclinical and clinical studies show that this approach is simple, effective, safe and well tolerated compared to standard chemical or biological adjuvants. Until now, these laser exposures have been performed using a diode-pumped solid-state laser (DPSSL) devices, which are expensive and require labor-intensive maintenance and special training. Development of an inexpensive, easy-to-use and small device would form an important step in translating this technology toward clinical application. Here we report that we have established a handheld, near-infrared (NIR) laser device using semiconductor diodes emitting either 1061, 1258, or 1301nm light that costs less than $4000, and that this device replicates the adjuvant effect of a DPSSL system in a mouse model of influenza vaccination. Our results also indicate that a broader range of NIR laser wavelengths possess the ability to enhance vaccine immune responses, allowing engineering options for the device design. This small, low-cost device establishes the feasibility of using a laser adjuvant approach for mass-vaccination programs in a clinical setting, opens the door for broader testing of this technology with a variety of vaccines and forms the foundation for development of devices ready for use in the clinic.

Topically applied methotrexate is rapidly delivered into skin by fractional laser ablation

OBJECTIVES

Methotrexate (MTX) is a chemotherapeutic and anti-inflammatory drug that may cause systemic adverse effects. This study investigated kinetics and biodistribution of MTX delivered topically by ablative fractional laser (AFXL).

METHODS

In vitro passive diffusion of 10 mg/ml MTX (1 w/v%) was measured from 0.25 to 24 h through AFXL-processed and intact porcine skin in Franz Cells (n = 46). A 2,940 nm fractional Erbium Yttrium Aluminium Garnet laser generated mid-dermal microchannels at 2.4% density, and 256 mJ/microchannel. HPLC quantified MTX-concentrations in extracts from mid-dermal skin sections, donor and receiver compartments. Fluorescence microscopy of UVC-activated MTX-fluorescence and desorption electro-spray ionization mass spectrometry imaging (DESI-MSI) evaluated MTX biodistribution.

RESULTS

AFXL-processed skin facilitated rapid MTX delivery through cone-shaped microchannels of 690 µm ablation depth, lined by the 47 µm thermal coagulation zone (CZ). Quantitatively, MTX was detectable by HPLC in mid-dermis after 15 min, significantly exceeded deposition in intact skin after 1.5 h, and saturated skin after 7 h at a 10-fold increased MTX-deposition versus intact skin (3.08 vs 0.30 mg/cm(3), p = 0.002). Transdermal permeation was < 1.5% of applied MTX before skin saturation, and increased up to 8.0% after 24 h. Qualitatively, MTX distributed into CZ within 15 min (p = 0.015) and further into surrounding dermal tissue after 1.5 h (p = 0.004). After skin saturation at 7 h, MTX fluorescence intensities in CZ and tissue were similar and DESI-MSI confirmed MTX biodistribution throughout the mid-dermal skin section.

CONCLUSIONS

MTX absorbs rapidly into mid-dermis of AFXL-processed skin with minimal transdermal permeation until skin saturation, suggesting a possible alternative to systemic MTX for some skin disorders.

Cutaneous drug delivery: an update

Cutaneous delivery of therapeutics represents a proven and attractive option for treating a variety of dermatologic conditions with minimal systemic side effects. Although there have been many innovations in drug delivery systems, the number of effective cutaneous drugs remains small, primarily because of the stratum corneum permeability barrier. Overcoming this barrier safely and reversibly to deliver large hydrophilic drugs cutaneously is one of the major challenges in the field of dermatologic therapy.

Skin resurfacing procedures: new and emerging options

The demand for skin resurfacing and rejuvenating procedures has progressively increased in the last decade and has sparked several advances within the skin resurfacing field that promote faster healing while minimizing downtime and side effects for patients. Several technological and procedural skin resurfacing developments are being integrated into clinical practices today allowing clinicians to treat a broader range of patients' skin types and pathologies than in years past, with noteworthy outcomes. This article will discuss some emerging and developing resurfacing therapies and treatments that are present today and soon to be available.

Pretreatment with ablative fractional laser changes kinetics and biodistribution of topical 5-aminolevulinic acid (ALA) and methyl aminolevulinate (MAL)

BACKGROUND AND OBJECTIVES

5-Aminolevulinic acid (ALA) and methyl aminolevulinate (MAL) are porphyrin precursors used topically for photodynamic therapy (PDT). Previous studies have established that ablative fractional laser (AFXL) increases topical drug uptake. We evaluated kinetics and biodistribution of ALA- and MAL-induced porphyrins on intact and disrupted skin due to AFXL.

MATERIALS AND METHODS

Two Yorkshire swine were exposed to CO2 AFXL (10.6 µm, 1,850 µm ablation depth) and subsequent topical application of ALA and MAL cream formulations (20%, weight/weight). Porphyrin fluorescence was quantified by digital fluorescence photography (30, 90, and 180 minutes) and fluorescence microscopy at specific skin depths (180 minutes).

RESULTS

Porphyrins gradually formed over time, differently on intact and AFXL-disrupted skin. On intact skin (no AFXL), fluorescence photography showed that MAL initially induced higher fluorescence than ALA (t = 30 minutes MAL 21.1 vs. ALA 7.7 au, t = 90 minutes MAL 39.0 vs. ALA 26.6 (P < 0.009)) but reached similar intensities for long-term applications (t = 180 minutes MAL 56.6 vs. ALA 52 au, P = ns). AFXL considerably enhanced porphyrin fluorescence from both photosensitizers (P < 0.05). On AFXL-exposed skin, MAL expressed higher fluorescence than ALA for short-term application (t = 30 minutes, AFXL-MAL 26.4 vs. AFXL-ALA 14.1 au, P < 0.001), whereas ALA over time overcame MAL and induced the highest fluorescence intensities obtained (t = 180 minutes, AFXL-MAL 98.6 vs. AFXL-ALA 112.0 au, P < 0.001). In deep skin layers, fluorescence microscopy showed higher fluorescence in hair follicle epithelium for ALA than MAL (t = 180 minutes, 1.8 mm, AFXL-MAL 35.3 vs. AFXL-ALA 46.7 au, P < 0.05).

CONCLUSIONS

AFXL changes kinetics and biodistribution of ALA and MAL. It appears that AFXL-ALA favors targeting deep structures.

Ablative laser assisted topical delivery of antifibrotics in the management of cicatricial ectropion

A variety of surgical techniques have traditionally been used to manage cicatricial ectropion. These techniques primarily aim at vertical lengthening of the anterior lamella and include a variety of skin flaps and grafts. Alternative techniques such as dermal filler injection to support the eyelid margin may also be used in the management of select patients with cicatricial ectropion. The application of different types of laser for scar revision throughout the body has rapidly evolved; similar mechanisms, principles and treatment rationale can be applied to the use of lasers in the management of cicatricial ectropion. Additionally, ablative lasers, such as Carbon Dioxide and Erbium:yttrium-aluminum-garnet lasers, may be used in the transdermal delivery of antifibrotic agents, such as interferon gamma, interferon alpha, vitamin D, triamcinolone and 5-fluorouracil, resulting in efficient target tissue penetration, limitation of systemic drug toxicity and decreased degradation. Although the combination of ablative fractional resurfacing and topical antifibrotic agents is a new treatment modality, there is a great potential for its efficient utility in the management of periocular scarring and cicatricial ectropion. The introduction of these innovative therapeutic modalities offers ophthalmologists a greater range of possible effective treatments to address periocular scar tissue and the resultant cicatricial ectropion.

Physical energy for drug delivery; poration, concentration and activation

Techniques for controlling the rate and duration of drug delivery, while targeting specific locations of the body for treatment, to deliver the cargo (drugs or DNA) to particular parts of the body by what are becoming called "smart drug carriers" have gained increased attention during recent years. Using such smart carriers, researchers have also been investigating a number of physical energy forces including: magnetic fields, ultrasound, electric fields, temperature gradients, photoactivation or photorelease mechanisms, and mechanical forces to enhance drug delivery within the targeted cells or tissues and also to activate the drugs using a similar or a different type of external trigger. This review aims to cover a number of such physical energy modalities. Various advanced techniques such as magnetoporation, electroporation, iontophoresis, sonoporation/mechnoporation, phonophoresis, optoporation and thermoporation will be covered in the review. Special emphasis will be placed on photodynamic therapy owing to the experience of the authors' laboratory in this area, but other types of drug cargo and DNA vectors will also be covered. Photothermal therapy and theranostics will also be discussed.

An update on the use of laser technology in skin vaccination

Vaccination via skin often induces stronger immune responses than via muscle. This, in line with potential needle-free, painless delivery, makes skin a very attractive site for immunization. Yet, despite decades of effort, effective skin delivery is still in its infant stage and safe and potent adjuvants for skin vaccination remain largely undefined. We have shown that laser technologies including both fractional and non-fractional lasers can greatly augment vaccine-induced immune response without incurring any significant local and systemic side effects. Laser illumination at specific settings can accelerate the motility of antigen-presenting cells or trigger release of 'danger' signals stimulating the immune system. Moreover, several other groups including the authors explore laser technologies for needle-free transcutaneous vaccine delivery. As these laser-mediated resurfacing technologies are convenient, safe and cost-effective, their new applications in vaccination warrant clinical studies in the very near future.

Basics and recent advances in peptide and protein drug delivery

While the peptide and protein therapeutic market has developed significantly in the past decades, delivery has limited their use. Although oral delivery is preferred, most are currently delivered intravenously or subcutaneously due to degradation and limited absorption in the gastrointestinal tract. Therefore, absorption enhancers, enzyme inhibitors, carrier systems and stability enhancers are being studied to facilitate oral peptide delivery. Additionally, transdermal peptide delivery avoids the issues of the gastrointestinal tract, but also faces absorption limitations. Due to proteases, opsonization and agglutination, free peptides are not systemically stable without modifications. This review discusses oral and transdermal peptide drug delivery, focusing on barriers and solutions to absorption and stability issues. Methods to increase systemic stability and site-specific delivery are also discussed.

Laser microporation of the skin: prospects for painless application of protective and therapeutic vaccines

Introduction:

In contrast to muscle and subcutaneous tissue, the skin is easily accessible and provides unique immunological properties. Increasing knowledge about the complex interplay of skin-associated cell types in the development of cutaneous immune responses has fueled efforts to target the skin for vaccination as well as for immunotherapy.

Areas covered:

This review provides an overview on skin layers and their resident immunocompetent cell types. Advantages and shortcomings of standard methods and innovative technologies to circumvent the outermost skin barrier are addressed. Studies employing fractional skin ablation by infrared lasers for cutaneous delivery of drugs, as well as high molecular weight molecules such as protein antigens or antibodies, are reviewed, and laserporation is introduced as a versatile transcutaneous vaccination platform. Specific targeting of the epidermis or the dermis by different laser settings, the resulting kinetics of uptake and transport and the immune response types elicited are discussed, and the potential of this transcutaneous delivery platform for allergen-specific immunotherapy is demonstrated.

Expert opinion:

Needle-free and painless vaccination approaches have the potential to replace standard methods due to their improved safety and optimal patient compliance. The use of fractional laser devices for stepwise ablation of skin layers might be advantageous for both vaccination against microbial pathogens, as well as immunotherapeutic approaches, such as allergen-specific immunotherapy. Thorough investigation of the underlying immunological mechanisms will help to provide the knowledge for a rational design of transcutaneous protective/therapeutic vaccines.