A clinical study of carbon dioxide lattice laser-assisted or microneedle-assisted 5-aminolevulinic acid-based photodynamic therapy for the treatment of hypertrophic acne scars

Laser Therapy in Hypertrophic and Keloid Scars: A Systematic Review and Network Meta-analysis

BACKGROUND

Laser therapy has emerged as a promising treatment modality for improving the appearance and symptoms associated with hypertrophic and keloid scars. In this network meta-analysis, we aimed to evaluate the efficacy of different laser types in treating hypertrophic and keloid scars.

METHODS

A comprehensive search of four databases was conducted to identify relevant studies published up until July 2023. Data were extracted from eligible studies and pooled as mean difference (MD) for continuous outcomes and risk ratio (RR) for dichotomous data in a network meta-analysis (NMA) model, using R software.

RESULTS

A total of 18 studies, comprising 550 patients, were included in the analysis. Pooling our data showed that fractional carbon dioxide (FCO2) plus 5-fluorouracil (5-FU) was superior to control in terms of Vancouver Scar Scale (VSS), pliability score, and thickness; [MD = - 5.97; 95% CI (- 7.30; - 4.65)], [MD = - 2.68; 95% CI (- 4.03; - 1.33)], [MD = - 2.22; 95% CI (- 3.13; - 1.31)], respectively. However, insignificant difference was observed among FCO2 plus 5-FU compared to control group in terms of erythema, vascularity, redness and perfusion, and pigmentation [MD = - 0.71; 95% CI (- 2.72; 1.30)], [MD = - 0.44; 95% CI (- 1.26; 0.38)], respectively.

CONCLUSION

Our NMA found that the FCO2 plus 5-FU was the most effective intervention in decreasing the VSS and thickness, while FCO2 plus CO2 was the most effective intervention in decreasing the pliability score. Further research is needed to determine the optimal laser parameters and long-term efficacy of laser therapy in hypertrophic and keloid scars.

LEVEL OF EVIDENCE IV

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Pharmacotherapy for Keloids and Hypertrophic Scars

Keloids (KD) and hypertrophic scars (HTS), which are quite raised and pigmented and have increased vascularization and cellularity, are formed due to the impaired healing process of cutaneous injuries in some individuals having family history and genetic factors. These scars decrease the quality of life (QOL) of patients greatly, due to the pain, itching, contracture, cosmetic problems, and so on, depending on the location of the scars. Treatment/prevention that will satisfy patients' QOL is still under development. In this article, we review pharmacotherapy for treating KD and HTS, including the prevention of postsurgical recurrence (especially KD). Pharmacotherapy involves monotherapy using a single drug and combination pharmacotherapy using multiple drugs, where drugs are administered orally, topically and/or through intralesional injection. In addition, pharmacotherapy for KD/HTS is sometimes combined with surgical excision and/or with physical therapy such as cryotherapy, laser therapy, radiotherapy including brachytherapy, and silicone gel/sheeting. The results regarding the clinical effectiveness of each mono-pharmacotherapy for KD/HTS are not always consistent but rather scattered among researchers. Multimodal combination pharmacotherapy that targets multiple sites simultaneously is more effective than mono-pharmacotherapy. The literature was searched using PubMed, Google Scholar, and Online search engines.

Advances in photodynamic therapy of pathologic scar

Pathologic scars include keloids and hypertrophic scars due to abnormal wound healing. Both cause symptoms of itching and pain; they also affect one's appearance and may even constrain movement. Such scars place a heavy burden on the individual's physical and mental health; moreover, treatment with surgery alone is highly likely to leave more scarring. Therefore, there is an urgent need for a treatment that is both minimally invasive and convenient. Photodynamic therapy (PDT) is an emerging safe and noninvasive technology wherein photosensitizers and specific light sources are used to treat malignant tumors and skin diseases. Research on PDT from both the laboratory and clinic has been reported. These findings on the treatment of pathologic scars using photosensitizers, light sources, and other mechanisms are reviewed in the present article.

Application of microneedling in photodynamic therapy: A systematic review

BACKGROUND

The application of photodynamic therapy (PDT) is pivotal in the management of diverse dermatologic conditions. Microneedling (MN) is a minimally invasive tool that is capable of inducing transient pores on the skin to facilitate transdermal drug delivery. Several studies have reported augmentation of PDT combined with MN. This systematic review analyzes the current studies on the efficacy and safety of MN-assisted PDT for skin diseases.

METHODS

The literature search using the PRISMA standard was completed through PubMed, Embase, Web of Science and CENTRAL from the establishment of the databases to November 2023. Two independent researchers finished the procedure.

RESULTS

A total of 12 articles and 413 subjects met our study criteria. This systematic review suggests that MN-assisted PDT can decrease the incubation time required for the photosensitizer and reduce skin lesions of actinic keratosis (AK) . The common side effect is pain and no serious adverse events were reported.

CONCLUSIONS

MN is an effective method to increase the transdermal delivery rate of photosensitizers. For different photosensitizers and disease, MN may show different clinical effects.

ALA-PDT promotes the death and contractile capacity of hypertrophic scar fibroblasts through inhibiting the TGF-β1/Smad2/3/4 signaling pathway

BACKGROUND

Hypertrophic scars, an abnormal wound-healing response to burn injuries, are characterized by massive fibroblast proliferation and excessive deposition of extracellular matrix and collagen. 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) is a promising therapy for hypertrophic scar, details of the mechanisms remain to be elucidated. In this study, we aimed to investigate the molecular mechanisms involved in ALA-PDT against hypertrophic scar fibroblasts.

METHODS

The morphologies of hypertrophic scar fibroblasts (HSFs) treated with ALA-PDT were observed under a light microscopy. The viability of HSFs was detected using the CCK-8 assay. HSFs-populated collagen gel contraction assays were conducted to examine the fibroblast contractility and the cytotoxicity of HSFs in 3D collagen tissues were observed using confocal microscopy. The effect of ALA-PDT on TGF-β1/Smad2/3/4 signaling pathway activation and effector gene expression were verified by immunoprecipitation, western blot and real-time quantitative PCR analysis.

RESULTS

We observed significant changes in cell morphology after ALA-PDT treatment of HSFs. As ALA concentration and light dose increased, the viability of HSFs significantly decreased. ALA-PDT can significantly alleviate the contractile capacity and promote the death of HSFs induced by TGF-β1 treatment in a three-dimensional collagen culture model. TGF-β1 treatment of HSFs can significantly induce phosphorylation of Smad2/3 (p-Smad2/3) in whole cells, as well as p-Smad2/3 and Smad4 proteins into the nucleus and increase the mRNA levels of collagen 1/3 and α-SMA. ALA-PDT hampers the TGF-β1-Smad2/3/4 signaling pathway activation by inducing K48-linked ubiquitination and degradation of Smad4.

CONCLUSIONS

Our results provide evidence that ALA-PDT can inhibit fibroblast contraction and promote cell death by inhibiting the activation of the TGF-β1 signaling pathway that mediates hypertrophic scar formation, which may be the basis for the efficacy of ALA-PDT in the treatment of hypertrophic scars.

Exosome Derived from Mesenchymal Stem Cells Alleviates Hypertrophic Scar by Inhibiting the Fibroblasts via TNFSF-13/HSPG2 Signaling Pathway

Background

Mesenchymal stem cell-derived exosomes (MSC-exo) have been shown to have significant potential in wound healing and scar relief processes. According to reports, TNFSF13 and HSPG2 are associated with various fibrotic diseases. The aim of this study is to investigate how TNFSF13 and HSPG2 affect the formation of hypertrophic scar (HS) and the mechanism by which exosomes regulate HS.

Methods

Immunohistochemistry, qRT-PCR, Western blot, and immunofluorescence were performed to measure TNFSF13 expression in HS skin tissues and hypertrophic scar fibroblast (HSF). HSF were treated with recombinant TNFSF13 protein and TNFSF13 siRNAs to probe the effect of TNFSF13 on the activity of HSF. The CCK-8, EdU, Transwell, and Western blot were used to investigate the role of TNFSF13 in viability, proliferation and inflammation. The influence of MSC-exo on the proliferation and function of HSF was determined by scratch and Western blot.

Results

TNFSF13 was dramatically up-regulated in HS skin tissues and HSF. Recombinant TNFSF13 protein increased cell viability, proliferation, migration, fibrosis, inflammation, and the binding between TNFSF13 and HSPG2 of HSF. The opposite results were obtained in TNFSF13 siRNAs transferred HSF. Furthermore, TNFSF13 activated the nuclear factor-κB (NF-κB) signaling pathway. Silencing of HSPG2 and inhibition of NF-κB remarkably eliminated the promoting effects of TNFSF13 on cell viability, proliferation, migration, fibrosis and inflammation of HSF. MSC-exo reduced α-SMA and COL1A1 inhibited the proliferation and migration of HSF by inhibiting TNFSF13 and HSPG2.

Conclusion

TNFSF13 activates NF-κB signaling pathway by interacting with HSPG2, which regulates the proliferation, migration, fibrosis and inflammatory response of HSF. Through the above mechanisms, knocking out TNFSF13 can inhibit the proliferation, migration, fibrosis and inflammatory response of HSF, whereas MSC-exo could reverse this process. These results suggest that MSC-exo alleviates HS by inhibiting the fibroblasts via TNFSF-13/HSPG2 signaling pathway.

Clinical study of modified photodynamic therapy combined with Taohong Siwu Decoction in treating hypertrophic scar after severe burn

OBJECTIVE

The aim of this study was to study the curative effect and the relative mechanism of modified photodynamic therapy combined with Taohong Siwu Decoction in the treatment of hyperplastic scar after severe burn, in order to provide a stable, safe and satisfactory scheme for scar repair.

METHODS

Forty cases with hyperplastic scars after severe burns admitted to the plastic surgery department from May 2021 to May 2022 were divided into a control group and an observation group by means of the random number table method. The control group was treated with ordinary laser therapy combined with Taohong Siwu Decoction, while the observation group was treated with modified photodynamic therapy combined with Taohong Siwu Decoction. The Vancouver Scar Scale (VSS) was assessed in both groups, and the clinical effectiveness of both groups was compared. HE-staining was performed on the scar tissue of the same patient before and after treatment to observe the changes in the arrangement of fibroblasts. The Vascular Endothelial Growth Factor (VEGF), β-Transforming Growth Factor (TGF-β), and Platelet-Derived Growth Factor (PDGF) in the tissue samples of both groups were detected by quantitative real-time PCR. The patients were followed up for 6 months, and their satisfaction, side effects, and scar recurrence were observed.

RESULTS

Compared with the control group, the VSS score in the observation group was lower (p < 0.05). The therapeutic effect of the observation group was superior to the control group after 3 months (p < 0.05). After 3-months of therapy, the arrangement of fibroblasts in the scar became looser in two groups, and the observation group was more looser. The VEGF, TGF-β and PDGF levels in tissue samples of the observation group were lower than those in the control group after 3 months of treatment (p < 0.05). The satisfaction of the observation group was higher than that of the control group (p < 0.05). The adverse reactions between the two groups showed no difference (p > 0.05), while the recurrence rate was lower in the observation group (p < 0.05).

CONCLUSION

Modified photodynamic therapy combined with Taohong Siwu Decoction shows remarkable efficacy in patients with hyperplastic scars after severe burns. It can improve the color, thickness, vascular distribution, and softness of the scar, and reduce the level of cytokines related to tissue repair. At the same time, it can improve patients' satisfaction with the aesthetic appearance and reduce the recurrence rate, providing a new comprehensive therapy that is safer and more effective, simple and quick, and easy to promote in the clinic.

5-Aminolevulinic Acid Photodynamic Therapy Combined with Intralesional Triamcinolone and 5-Fluorouracil to Treat Acne Hypertrophic Scar

Background

Acne is a chronic inflammatory disease of the pilosebaceous unit. Improper treatment of acne can lead to skin lesions in some people. Acne hypertrophic scar is relatively rare, but it significantly affects the appearance and beauty, and usually has a great psychological and social impact on patients.

Objective

To evaluate the clinical efficacy and safety of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) combined with 5-fluorouracil (5-FU) injection and triamcinolone acetonide (TAC) solution in the treatment of acne hypertrophic scars.

Methods

This article included 13 outpatients with acne accompanied by acne hypertrophic scar who were treated from September 2018 to September 2022. All patients received ALA-PDT combined with intralesional injection of 5-FU and TAC. At first, patients received ALA-PDT once every two weeks. After the third ALA-PDT, 5-FU and TAC were mixed in a ratio of 3:7, and then immediately injected in the local scars. The effect was observed after 1 month. If the effect is not obvious, a further injection of 5-FU and TAC to the lesion is necessary. The patients were followed up for 6 months. The Vancouver Scars Scale (VSS) was used to evaluate the efficacy before and after treatment and photos of patients were collected.

Results

After ALA-PDT combined with intralesional 5-FU and TAC, all patients achieved good clinical efficacy. 23.08% of patients received one local injection and 76.92% received two local injections. After treatment, the scar lesions were reduced and flattened, and the scars became soft. The total score of VSS after treatment was significantly lower than before, and the difference was statistically significant (P<0.05). The main adverse reactions were pain, erythema, and pigmentation, which can subside within 3 weeks. There was no recurrence after 6 months of follow-up.

Conclusion

ALA-PDT combined with intralesional injection of 5-FU and TAC significantly affects acne hypertrophic scars, which is worthy of further in-depth and large-scale research.

Laser-Assisted Drug Delivery in the Treatment of Scars, Rhytids, and Melasma: A Comprehensive Review of the Literature

Although broad reviews on laser-assisted drug delivery (LADD) have been published in the past, an updated focused examination of its utility in the context of common, treatment-resistant, dermatologic conditions has not been published. This article reports a comprehensive scoping review of the potential benefits of LADD compared to laser or drug monotherapy for the treatment of 3 such conditions: scars, rhytids, and melasma. A PubMed (National Institutes of Health; Bethesda, MD) search was conducted for keywords including "laser-assisted drug delivery," "scar," "rhytid," and "melasma." Out-of-scope studies were excluded. To evaluate the efficacy of LADD for the treatment of scars, relevant articles were categorized by scar type: hypertrophic/keloid, atrophic, and hypopigmented. LADD, with both ablative and nonablative laser types, was studied in combination with corticosteroids, botulinum toxin-A (BTX-A), 5-fluorouracil, 5-aminolevulinic acid photodynamic therapy, stem cells, platelet-rich plasma, and prostaglandin analogs for the treatment of scars. Some randomized controlled trials demonstrated the efficacy of LADD, whereas others showed no significant differences in clinical outcomes but demonstrated reduced adverse effects. Regarding rhytids, laser treatment has been combined with various cosmeceuticals, including poly-L-lactic acid, topical retinaldehyde, and topical BTX-A. The studies reviewed supported the use of LADD with these drugs over monotherapy. Some studies showed that LADD was effective for the absorption of drugs such as poly-L-lactic acid and BTX-A which are often not effective topically. For melasma treatment, LADD with tranexamic acid and hydroquinone was superior in some studies, but not significantly different than monotherapy in other studies. LADD with certain drugs could be considered to treat scars, rhytids, and melasma.

LEVEL OF EVIDENCE: 5

A systematic review of the comparison between needling (RF-needling, meso-needling, and micro-needling) and ablative fractional lasers (CO2, erbium YAG) in the treatment of atrophic and hypertrophic scars

The aim of this study is to compare needling (RF-needling, meso-needling, micro-needling) and ablative fractional lasers (CO2, erbium-YAG) in the treatment of atrophic and hypertrophic scars in a systematic review. The database was searched, and 10 articles were selected that were relevant in terms of content, topic, and purpose and met the inclusion criteria. Of all the articles reviewed in this study, there were 2 randomized split-face trials (20%), 1 controlled nonrandomized trial (10%), 1 controlled randomized phase III clinical trial (10%), 1 prospective trial (10%), 1 prospective nonrandomized open-label trial (10%), and 1 randomized comparative trial (10%), with the type of study not reported in 3 articles. We used Endnote X8 to review the articles and extract data. After review, the studies were analyzed and categorized. No statistically significant difference was found between the two methods, laser and micro-needling, in the treatment of atrophic and hypertrophic scars in 60% of the articles studied, and both showed significant improvement (70% or more improvement to complete response). Significant improvement was noted in 20% of the studies reviewed for the laser and micro-needling treatment methods. The results of this study show that needling and ablative fractional lasers are tolerable and safe procedures with no significant difference in the treatment of skin scars in sixty percent of the studies.

Inhibition of ANGPT2 activates autophagy during hypertrophic scar formation via PI3K/AKT/mTOR pathway

BACKGROUND

Hypertrophic scar (HS), a fibroproliferative disorder caused by aberrant wound healing following skin injuries such as burns, lacerations and surgery, is characterized by invasive proliferation of fibroblasts and excessive extracellular matrix (ECM) accumulation. The dysregulation of autophagy is the pathological basis of HS formation. Previously, angiopoietin-2 (ANGPT2) was found to be overexpressed in HS fibroblasts (HSFs) compared with normal skin fibroblasts. However, whether ANGPT2 participates in the process of HS formation and the potential molecular mechanisms are not clear.

OBJECTIVE

This study is intended to figure out the role of ANGPT2 and ANGPT2-mediated autophagy during the development of HS.

METHODS

RT-qPCR was used to detect ANGPT2 expression in HS tissues and HSFs. HSFs were transfected with sh-ANGPT2 to knock down ANGPT2 expression and then treated with MHT1485, the mTOR agonist. The effects of sh-ANGPT2 or MHT1485 on the proliferation, migration, autophagy and ECM accumulation of HSFs were evaluated by CCK-8 assay, Transwell assay and western blotting. The expression of PI3K/Akt/mTOR pathway-related molecules (p-PI3K, p-Akt and p-mTOR) was assessed by western blotting.

RESULTS

ANGPT2 expression was markedly upregulated in HS tissues and HSFs. ANGPT2 knockdown decreased the expression of p-PI3K, p-Akt and p-mTOR. ANGPT2 knockdown activated autophagy and inhibited the proliferation, migration, and ECM accumulation of HSFs. Additionally, the treatment of MHT1485, the mTOR agonist, on ANGPT2-downregulated HSFs, partially reversed the influence of ANGPT2 knockdown on HSFs.

STUDY LIMITATIONS

The study lacks the establishment of more stable in vivo animal models of HS for investigating the effects of ANGPT2 on HS formation in experimental animals.

CONCLUSIONS

ANGPT2 downregulation represses growth, migration, and ECM accumulation of HSFs via autophagy activation by suppressing the PI3K/Akt/mTOR pathway. Our study provides a novel potential therapeutic target for HS.

Photoresponsive polymeric microneedles: An innovative way to monitor and treat diseases

Microneedles (MN) technology is an emerging technology for the transdermal delivery of therapeutics. When combined with photoresponsive (PR) materials, MNs can deliver therapeutics precisely and effectively with enhanced efficacy or synergistic effects. This review systematically summarizes the therapeutic applications of PRMNs in cancer therapy, wound healing, diabetes treatment, and diagnostics. Different PR approaches to activate and control the release of therapeutic agents from MNs are also discussed. Overall, PRMNs are a powerful tool for stimuli-responsive controlled-release therapeutic delivery to treat various diseases.

Photodynamic therapy for leishmaniasis: Recent advances and future trends

Leishmaniasis has infected more than 12 million people worldwide. This neglected tropical disease, causing 20,000-30,000 deaths per year, is a global health problem. The emergence of resistant parasites and serious side effects of conventional therapies has led to the search for less toxic and non-invasive alternative treatments. Photodynamic therapy is a promising therapeutic strategy to produce reactive oxygen species for the treatment of leishmaniasis. In this regard, natural and synthetic photosensitizers such as curcumin, hypericin, 5-aminolevulinic acid, phthalocyanines, phenothiazines, porphyrins, chlorins and nanoparticles have been applied. In this review, the recent advances on using photodynamic therapy for treating Leishmania species have been reviewed.