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

Laser-mediated Solutions: Breaking Barriers in Transdermal Drug Delivery

Skin diseases pose challenges in treatment due to the skin's complex structure and protective functions. Topical drug delivery has emerged as a preferred method for treating these conditions, offering localized therapy with minimal systemic side effects. However, the skin's barrier properties frequently limit topical treatments' efficacy by preventing drug penetration into deeper skin layers. In recent years, laser-assisted drug delivery (LADD) has gained attention as a promising strategy to overcome these limitations. LADD involves using lasers to create microchannels in the skin, facilitating the deposition of drugs and enhancing their penetration into the target tissue. Several lasers, such as fractional CO2, have been tested to see how well they work at delivering drugs. Despite the promising outcomes demonstrated in preclinical and clinical studies, several challenges persist in implementing LADD, including limited penetration depth, potential tissue damage, and the cost of LADD systems. Furthermore, selecting appropriate laser parameters and drug formulations is crucial to ensuring optimal therapeutic outcomes. Nevertheless, LADD holds significant potential for improving treatment efficacy for various skin conditions, including skin cancers, scars, and dermatological disorders. Future research efforts should focus on optimizing LADD techniques, addressing safety concerns, and exploring novel drug formulations to maximize the therapeutic benefits of this innovative approach. With continued advancements in laser technology and pharmaceutical science, LADD has the potential to revolutionize the field of dermatology and enhance patient care.

A Comprehensive Review of Non-Surgical Treatments for Hypertrophic and Keloid Scars in Skin of Color

Hypertrophic and keloid scars are fibroproliferative growths resulting from aberrant wound healing. Individuals with Fitzpatrick skin types (FSTs) IV-VI are particularly predisposed to hypertrophic and keloid scarring, yet specific guidelines for these populations are still lacking within the literature. Therefore, this comprehensive review provides a list of various treatments and considerations for hypertrophic and keloid scarring in patients with skin of color. We constructed a comprehensive PubMed search term and performed quadruple-blinded screening on all resulting studies to achieve this objective. Our findings demonstrate 1) the lack of efficacious treatments for raised scars within this population and 2) the need to empirically investigate individualized and multimodal therapeutic options for those with skin of color.

Comprehensive Review of Thermomechanical Fractional Injury Device: Applications in Medical and Cosmetic Dermatology

Objective

Our aim was to review the current and emerging dermatological applications of the novel thermomechanical fractional injury (TMFI) device, Tixel® (Novoxel, Netanya, Israel).

Methods

A systematic review of PubMed using the search terms of "Tixel", "thermomechanical fractional", ["thermomechanical ablation" and "skin"], and ["thermomechanical ablation" and "dermatology"].

Results

Thirty-six articles matched our inquiry. Fifteen articles did not meet inclusion criteria. Of the remaining 21 articles, eight were related to device-assisted drug delivery, seven related to photoaging, and seven related to scientific/ preclinical exploration. Preclinical studies have shown ablative and non-ablative microchannel formation similar to that of CO₂ laser but without charring, with clinical studies demonstrating efficacy for a wide range of applications including rhytides, hypertrophic scarring, infantile hemangiomas, and acne/rosacea. The treatment is well tolerated with minimal discomfort and downtime, showing promise for pain-averse and pediatric populations. Few adverse events have been reported, with a high degree of safety demonstrated in all Fitzpatrick types.

Limitations

Heterogeneous result reporting among studies. Limited number of randomized controlled trials.

Conclusion

Tixel® is an emerging TMFI device with a wide range of current and potential applications, including device-assisted drug delivery and treatment of rhytides, photoaging, and scars among other conditions. The device has both ablative and non-ablative settings and has been safely used in all Fitzpatrick skin types. Larger and randomized controlled trials are needed to compare this device to current standard of care treatments.

Platycodin D inhibits the proliferation and migration of hypertrophic scar-derived fibroblasts and promotes apoptosis through a caspase-dependent pathway

Abnormal fibroblast proliferation and excessive extracellular matrix (ECM) deposition lead to the formation of hypertrophic scars (HSs). However, there is no satisfactory method to inhibit the occurrence and development of HSs. In our study, platycodin D (PD), a natural compound extracted from Platycodon grandiflorus, inhibited HSs formation both in vitro and in vivo. First, qRT-PCR and Western blot were used to confirm PD dose-dependently downregulated the expression of Col I, Col III and α-SMA in human hypertrophic scar-derived fibroblasts (HSFs) (p < 0.05). Second, cck-8, transwell and wound healing assays verified PD suppressed the proliferation (p < 0.05) and migration of HSFs (p < 0.05), and inhibited the differentiation of HSFs into myofibroblasts. Moreover, PD-induced HSFs apoptosis were analyzed by flow cytometry and the apoptosis was activated through a caspase-dependent pathway. The rabbit ear scar model was used to further confirm the inhibitory effect of PD on collagen and α-SMA deposition. Finally, Western blot analysis showed that PD reduced TGF-β RI expression (p < 0.05) and affected matrix metalloproteinase 2 (MMP2) protein levels (p < 0.05). In conclusion, our study showed that PD inhibited the proliferation and migration of HSFs by inhibiting fibrosis-related molecules and promoting apoptosis via a caspase-dependent pathway. The TGF-β/Smad pathway also mediated the inhibition of HSFs proliferation and HSFs differentiation into myofibroblasts. Therefore, PD is a potential therapeutic agent for HSs and other fibrotic diseases.

A Review of Hypertrophic Scar and Keloid Treatment and Prevention in the Pediatric Population: Where Are We Now?

Significance: This body of work gives a concise and comprehensive overview for the clinician and scientist on the latest treatment modalities for hypertrophic scars (HTS) and keloids in the pediatric population, as well as the most promising methods of prevention currently being investigated. This review will serve as a guide to the clinician for treatment selection and as an efficient tool for the scientist to achieve a comprehensive overview of the scientific literature to guide their future experiments aimed at pathologic scar prevention. Recent Advances: Current studies in the literature suggest carbon dioxide (CO₂) laser and E-light (bipolar radiofrequency, intense pulsed light, and cooling) are two of the most effective treatment modalities for HTS, while surgical excision+CO₂ laser+triamcinolone injection was one of the most successful treatments for keloids. In animal models, drug impregnated electrospun nanofiber dressings offer encouraging results for HTS prevention, while Kelulut honey showed promising results for keloid prevention. Critical Issues: Treatment outcome reproducibility is hindered by small cohorts of patients, inadequate-follow up, and variability in assessment tools. Prevention studies show multiple ways of achieving the same result, yet fall short of complete prevention. Furthermore, some studies that have purported full prevention have not been validated. Future Directions: To establish a standard of care, large clinical trials of the most successful modalities in small cohorts are needed. The key for prevention will be validation in animal models of the most successful methods, followed by translational and clinical studies.

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.

Botulinum toxin type a intralesional monotherapy for treating human hypertrophic scar in a dose-dependent manner: In an animal model

BACKGROUND

The effect of Botulinum toxin type A (BTX-A) in treating or preventing a hypertrophic scar (HS) had been reported in clinical studies. However, the dose-effect relationship remains unclear.

OBJECTIVE

To study the dose-effect relationship of BTX-A intralesional monotherapy treating human HS.

METHODS

Six HS tissues were collected from six patients. Each tissue was segmented into 24 specimens and split into four groups: negative control (group A), 0.5U BTX-A (group B), 1U BTX-A (group C), and 2U BTX-A (group D). Six nude mice, each was prepared by implanting four specimens (one from each group) into the back for a total of 24 specimens. The process mentioned above were repeated six times. A re-entry operation was performed to obtain the specimens after 8 weeks. The weight of HS, the expression of decorin and TGF-β₁, the proliferation, and migration ability of hypertrophic scar fibroblasts (HSFBs) were compared among groups.

RESULTS

The weight of HS, the expression of decorin and TGF-β₁, the proliferation, and migration ability of HSFBs showed significant differences in groups C and D as compared to group A; there has been no statistical significance in group B.

CONCLUSION

BTX-A showed significant therapeutic efficacy when compared with the negative control group in a dose-dependent manner. BTX-A can reduce the weight of HS, upregulate the expression of decorin, downregulate the expression of TGF-β₁, and inhibit HSFBs proliferation and migration ability. This study indicates that BTX-A intralesional monotherapy treating HS should reach a threshold dose to achieve an effective treatment, and a high dose of BTX-A is more effective than a low dose.

High-Dose Steroid Dissolving Microneedle for Relieving Atopic Dermatitis

Dissolving microneedles (DMN) supplemented with therapeutic molecules have been developed to enhance transdermal delivery efficiency of topically applied drugs in a minimally invasive manner. However, the dose of the drugs in DMN system is limited owing to the low solubility of drug. In fact, although triamcinolone acetonide (TA) is one of the most widely prescribed drugs for relieving atopic dermatitis (AD), its poor dissolving nature makes it difficult to design and fabricate DMN containing therapeutic dosage of TA. In this study, TA suspension is introduced to encapsulate therapeutic dosage of TA. Sonication and composition optimization of polymers is key to fabricate high dose TA-DMN to induce particle size reduction and dispersion stability of suspension, respectively. After confirming the physical performance of TA-DMN using the selected formulation in vitro, the anti-inflammatory effects of TA-DMN are evaluated in vivo using a mouse model affected with skin inflammation to mimic AD in humans. Herein, high-dose TA-DMN is presented as a candidate agent for relieving AD and, furthermore, for wide application in the treatment of skin inflammatory diseases in which high-dose steroid drugs are required.

Drug delivery to optimize angiogenesis imbalance in keloid: A review

The wound healing process involves three continuous stages. Where, any imbalance can lead to the formation of unwanted keloids, hypertrophic scar, or tumors. Keloids are any unpleasant, non-compliant comorbidity affecting a major section of people around the globe who acquire it either genetically or by pathological means as a result of a skin injury. Angiogenesis is unavoidable in the healing process after an injury or disruption of skin to promote tissue regeneration. Uncontrolled angiogenesis during the healing process can initiate the unwanted response in the wound that facilitate keloid. Angiogenic therapy is adapted to accelerate healing after an injury. Else ways, there exists a risk of keloid formation due to excessive angiogenesis during the wound healing process. There are numerous strategies to treat keloid. Anti-angiogenic factors are provided to patients post-surgery to prevent the keloid formation; however, they come into the picture after the formation of keloid. The available strategies to treat keloids are steroidal injections, surgical excision of the keloid, radiotherapy, pressure therapy, the use of cryosurgery, and many more. The available treatments are not promising in reducing the recurrent rate of keloids as there are chances of high re-occurrences with similar/larger lesions on the removed keloid site. In this review, we are discussing the importance of controlled angiogenesis with the help of controlled drug delivery strategies enabling the wound healing process without the induction of keloid.

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.