Botulinum toxin type A: implications in wound healing, facial cutaneous scarring, and cleft lip repair

Evaluation of the Effect of Botulinum Toxin A on the Lymphatic Endothelial Cells

INTRODUCTION

Botulinum toxin A (BoTA) is a neurotoxin formed by Clostridium botulinum, with a broad medical application spectrum. While the primary effect of BoTA is on the muscles, the effects of BoTA in other systems including the blood vasculature have already been examined, revealing unexpected actions. However, no studies exist to the best of our knowledge regarding the potential effects of BoTA on the lymphatic vascular system, possessing a critical role in health and disease. Isolated human lymphatic endothelial cells (LECs) were cultured in dedicated in vitro culture systems. The analysis including imaging and cell culture approaches as well as molecular biology techniques is performed to examine the LEC alterations occurring upon exposure to different concentrations of BoTA.

MATERIALS AND METHODS

Human LECs were cultured and expanded on collagen-coated petri dishes using endothelial basal medium and the commercial product Botox from Allergan as used for all our experiments. Harvested cells were used in various in vitro functional tests to assess the morphologic and functional properties of the BoTA-treated LECs. Gene expression analysis was performed to assess the most important lymphatic system-related genes and pathways.

RESULTS

Concentrations of 1, 5 or 10 U of BoTA did not demonstrate a significant effect regarding the proliferation and migration capacity of the LECs versus untreated controls. Interestingly, even the smallest BoTA dose was found to significantly decrease the cord-like-structure formation capacity of the seeded LECs. Gene expression analysis was used to underpin possible molecular alterations, suggesting no significant effect of BoTA in the modification of gene expression versus the starvation medium control.

CONCLUSION

LECs appear largely unaffected to BoTA treatment, with an isolated effect on the cord-like-structure formation capacity. Further work needs to assess the effect of BoTA on the smooth-muscle-cell-covered collecting lymphatic vessels and the possible aesthetic implications of such an effect, due to edema formation.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Five decades of the use of botulinum toxin in ophthalmology

Botulinum toxin (BoNT) has been known for over 50 years. It has conquered many areas of medicine and has become indispensable in contemporary medicine. Now, BoNT is used to treat at least 26 conditions in six medical specialties. Although the use of BoNT began in strabology, it became the gold standard for many ophthalmologic pathologies. The present review of the literature focuses on the use of BoNT in ophthalmology and treatment of the following conditions: blepharospasm, facial hemispasm, facial palsy, spastic entropion, strabismus, endocrine orbitopathy, convergence spasm, and facial trauma. We conclude that nearly half a century of experience in utilizing BoNT in ophthalmology ensured a satisfactory level of effectiveness and safety for patients with many pathologies. Areas of future research include the application of BoNT in new selected indications, the development of the route of application without injections, and the development of long-acting BoNT forms for patients who require repeated long-term treatment.

Experimental study on the effect and mechanism of adipose stem cell-derived exosomes combined with botulinum toxin A on skin trauma in rats

BACKGROUND

Adipose stem cell-derived exosomes (ADSC-EXO) and botulinum toxin type A (BTX-A) individually showed a therapeutic effect on skin wound repair.

AIMS

This study investigated their synergistic effect on promoting skin wound healing in vitro and in vivo and the underlying molecular events.

METHODS

ADSCs were isolated from Sprague-Dawley (SD) rats to obtain ADSC-EXO by ultrafiltration and ultracentrifugation and were confirmed using nanoparticle tracking analysis and transmission electron microscopy. Human skin fibroblasts (HSF) were cultured and treated with or without ADSC-EXO, BTX-A, or their combination. Changes in cell phenotypes and protein expression were analyzed using different in vitro assays, and a rat skin wound model was used to assess their in vivo effects.

RESULTS

The isolated ADSC-EXO from primarily cultured ADSCs had a circular vesicle shape with a 30-180 nm diameter. Treatment of HSF with ADSC-EXO and/or BTX-A significantly accelerated HSF migration in vitro and skin wound healing in a rat model. Moreover, ADSC-EXO plus BTX-A treatment dramatically induced VEGFA expression but reduced COL III and COL I levels in vivo. ADSC-EXO and/or BTX-A treatment significantly upregulated TGF-β3 expression on Day 16 after surgery but downregulated TGF-β1 expression, suggesting that ADSC-EXO plus BTX-A promoted skin wound healing and reduced inflammatory cell infiltration.

CONCLUSIONS

The ADSC-EXO plus BTX-A treatment demonstrated a synergistic effect on skin wound healing through upregulation of VEGF expression and the TGF-β3/TGF-β1 and COL III/COL I ratio.

The effects of mechanical force on fibroblast behavior in cutaneous injury

Wound healing results in the formation of scar tissue which can be associated with functional impairment, psychological stress, and significant socioeconomic cost which exceeds 20 billion dollars annually in the United States alone. Pathologic scarring is often associated with exaggerated action of fibroblasts and subsequent excessive accumulation of extracellular matrix proteins which results in fibrotic thickening of the dermis. In skin wounds, fibroblasts transition to myofibroblasts which contract the wound and contribute to remodeling of the extracellular matrix. Mechanical stress on wounds has long been clinically observed to result in increased pathologic scar formation, and studies over the past decade have begun to uncover the cellular mechanisms that underly this phenomenon. In this article, we will review the investigations which have identified proteins involved in mechano-sensing, such as focal adhesion kinase, as well as other important pathway components that relay the transcriptional effects of mechanical forces, such as RhoA/ROCK, the hippo pathway, YAP/TAZ, and Piezo1. Additionally, we will discuss findings in animal models which show the inhibition of these pathways to promote wound healing, reduce contracture, mitigate scar formation, and restore normal extracellular matrix architecture. Recent advances in single cell RNA sequencing and spatial transcriptomics and the resulting ability to further characterize mechanoresponsive fibroblast subpopulations and the genes that define them will be summarized. Given the importance of mechanical signaling in scar formation, several clinical treatments focused on reducing tension on the wound have been developed and are described here. Finally, we will look toward future research which may reveal novel cellular pathways and deepen our understanding of the pathogenesis of pathologic scarring. The past decade of scientific inquiry has drawn many lines connecting these cellular mechanisms that may lead to a map for the development of transitional treatments for patients on the path to scarless healing.

Botulinum Toxin Type A for the Treatment of Skin Ulcers: A Review Article

The normal biological wound healing process consists of three precisely and highly programmed phases that require optimal conditions including internal and external factors. Any negative factors that disrupt the sequence or time frame of the healing mechanism can result in a non-healing wound or chronic ulcers. Botulinum neurotoxin A (BoNT-A) which is generally known as anti-contraction of muscles has been reported as a successful treatment in various types of chronic ulcers. The aim of this study is to review the outcome of treatment with BoNT-A for chronic skin ulcers. The results demonstrated some positive effects of BoNT-A on chronic ulcers. Ischemic ulcers secondary to Raynaud’s phenomenon seem to be the most promising type of ulcers that have benefited from BoNT-A. The rationale behind using BoNT-A to fasten the wound healing process is also discussed. Further clinical trial studies should be conducted to affirm the efficacy of wound healing using BoNT-A administration.

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 1: therapeutic applications

Objective An evidence-based review on the safety and efficacy of botulinum toxin type-A (BoNTA) in orofacial conditions, focusing on the therapeutic applications and role of BoNTA as an adjuvant treatment.Data source and selection Data was collected using PubMed (Medline), Cochrane Library of Systematic Reviews and Cochrane Central Register of Controlled Trials electronic databases. Having satisfied the search parameters, 32 studies for therapeutic applications and 26 for BoNTA as an adjunctive treatment were included. The quality of relevant studies was assessed using the Best Evidence Topics (BETs) Critical Appraisal Tool.Data extraction The highest level of evidence (LOE) behind BoNTA safety and efficacy was for wound healing and scar management in the orofacial surgery context, where BoNTA was presented as an adjunctive modality. Level-I evidence was controversial for temporomandibular disorders and bruxism. However, it showed promising results for painful temporomandibular disorders of myogenic origin refractory to conservative therapies, and to decrease muscle contraction intensity in sleeping bruxism. There was only one level-II study for persistent recurrent aphthous stomatitis. Data showed limited level-III evidence for orofacial pain conditions (temporomandibular joint recurrent dislocation and pain, burning mouth syndrome or atypical odontalgia), oral cancer complications, or as an adjuvant to maxillofacial and orthognathic surgeries. Benefits of BoNTA in prosthodontics had weak level-IV evidence. No evidence was found among the periodontology field.Conclusion There is growing evidence to support the safety and efficacy of BoNTA in the investigated orofacial pathological conditions, with high levels of satisfaction from the patient and clinician perspective. However, there are some inconsistencies and limited high-quality evidence available. Well-designed controlled clinical trials are necessary to evaluate long-term safety, efficacy and cost-effectiveness before BoNTA is widely adopted with irrefutable evidence-based clinical guidelines.

The effect of botulinum toxin A in unilateral cleft lip scar: comparison of results with different sites of injection

Botulinum toxin type A (BTA) injections into the subjacent orbicularis oris muscle have been shown to improve appearance and produce narrower cheiloplasty scars. This study was performed to determine the effect of BTA injected at different sites on the unilateral cleft lip scar and cleft side nostril width. A double-blind, randomized prospective trial was conducted involving 64 consecutive patients with unilateral cleft lip undergoing primary cheiloplasty between September 2016 and January 2019. The patients were randomized to receive BTA injections either into the subjacent orbicularis oris muscle (4 points group) or into the bilateral nasolabial fold region (6 points group) during cheiloplasty. The scars were assessed by photographic scar width measurements and Vancouver scar scale assessment tool. The cleft side nostril width was compared to the non-cleft side width. Fifty-six patients completed the trial, 24 in the 4 points group and 31 in the 6 points group. There was no significant difference in scar width or nostril width measurements between the groups at the end of follow-up. The Vancouver scar scale assessment was also similar between the groups. There was no significant difference in scar width or nostril width measurements after cleft lip repair between patients treated with botulinum toxin injections to the subjacent orbicularis oris muscle and patients treated with injections in the nasolabial region.

A novel treatment for prevention of post-traumatic elbow stiffness using onaBotulinum toxin type A: a prospective placebo controlled randomized trial

Approximately 30% of all upper extremity fractures are elbow fractures which may result elbow stiffness. This study aimed to investigate the efficacy of onaBotulinum Toxin type A injection to prevent post-traumatic pain and elbow-stiffness. All patients were included who presented to a single surgeon with supracondylar/ intraarticular distal humerus fractures, proximal ulna and radius fractures. The study was developed in a randomized placebo controlled study between 2003-2007. The Disabilities of the Arm, Shoulder, and Hand (DASH) score as well as the arc-of-motion (AOM) were assessed after three, six, twelve-months and final follow up for evaluation. Of the 31-patients included, 15-patients (48.4%) received Botox injections. In all patients no complication was observed when injecting a dosage 100-units for the brachialis and biceps brachii muscles. Furthermore, it was an effective method to prevent post-traumatic elbow stiffness, lasting six- months. Significant differences in DASH, VAS-score and ROM after three-months between the Botox and control group (DASH 21.6±11.0 vs. 55.3±11.0 ; VAS 1.2±5.2 vs. 5.7±21.9 ; ROM 103±7.6 vs. 73±6.3 ; p>0.05) were identified in the prospective group. Botulinum toxin is a safe, reliable and effective treatment to prevent post-traumatic elbow stiffness. Our study demonstrates improved early range-of- motion (p<0.05), better extension after 6 weeks and improved functional outcome including VAS and DASH score (p<0.05).

Treatment of keloids and hypertrophic scars. Position statement of the Brazilian expert group GREMCIQ

Keloids (K) and hypertrophic scars (HS) are abnormal responses to wound healing that occur as the result of dermal inflammation. Despite the advances on their treatment, many patients still suffer from the negative effects of excessive scarring; its approach is impaired by the lack of objective data on different treatments and the large genetic variability among patients and the difficulties in producing multicentre studies. Their incidence among the Brazilian population is high, as the result of an admixture of Amerindians, Europeans and Africans ancestral roots. With the aim of producing multicentre studies on K and HS, a panel of senior Brazilian dermatologists focused on their treatment was invited to contribute with the K and HS Treatment Brazilian Guidelines. In the first part of this study, different treatment modalities for keloids and HS are fully reviewed by the panel. The second part of the study presents a consensus recommendation of treatment for different types of lesions. More than a literature review, this article aims to show the pitfalls and pearls of each therapeutic option, as well as a therapeutic approach by the Panel of Experts on keloids and Scars on a highly mixed population, providing simple guidelines.

Non-invasive Intrauterine Administration of Botulinum Toxin A Enhances Endometrial Angiogenesis and Improves the Rates of Embryo Implantation

Endometrial angiogenesis plays crucial roles in determining the endometrial receptivity. Defects in endometrial receptivity often cause repeated implantation failure, which is one of the major unmet needs for infertility and contributes a major barrier to the assisted reproductive technology. Despite the numerous extensive research work, there are currently no effective evidence-based treatments to prevent or cure this condition. As a non-invasive treatment strategy, botulinum toxin A (BoTA) was administered into one side of mouse uterine horns, and saline was infused into the other side of horns for the control. Impact of BoTA was assessed in the endometrium at 3 or 8 days after infusion. We demonstrated that BoTA administration enhances the capacity of endothelial cell tube formation and sprouting. The intrauterine BoTA administration significantly induced endometrial angiogenesis displaying increased numbers of vessel formation and expression levels of related marker genes. Moreover, BoTA intrauterine application promoted the endometrial receptivity, and the rates of embryo implantation were improved with BoTA treatment with no morphologically retarded embryos. Intrauterine BoTA treatment has a beneficial effect on vascular reconstruction of functional endometrium prior to embryo implantation by increasing endometrial blood flow near the uterine cavity suggesting BoTA treatment as a potential therapeutic strategy for patients who are suffering from repeated implantation failure with the problems with endometrial receptivity.

Dramatic neurological and biological effects by botulinum neurotoxin type A on SH-SY5Y neuroblastoma cells, beyond the blockade of neurotransmitter release

BACKGROUND

Gene expression profile analysis on mammalian cell lines and animal models after exposure to botulinum neurotoxin (BoNT) has been investigated in several studies in recent years. Microarray analysis provides a powerful tool for identifying critical signaling pathways involved in the biological and inflammatory responses to BoNT and helps determine the mechanism of the function of botulinum toxins. One of the pivotal clinical characteristics of BoNT is its prolonged on-site effects. The role of BoNT on the blockage of neurotransmitter acetylcholine release in the neuromuscular junction has been well established. However, the effects of the treatment time of BoNT on the human cellular model and its potential mechanism remain to be defined.

METHODS

This study aimed to use gene microarray technology to compare the two physiological critical time points of BoNT type A (BoNT/A) treatment of human neuroblastoma cells and to advance our understanding of the profound biological influences that toxin molecules play in the neuronal cellular system. SH-SY5Y neuroblastoma cells were treated with BoNT/A for 4 and 48 h, which represent the time needed for the entrance of toxin into the cells and the time necessary for the initial appearance of the on-site effects after BoNT application, respectively.

RESULTS

A comparison of the two time points identified 122 functional groups that are significantly changed. The top five groups are alternative splicing, phosphoprotein, nucleus, cytoplasm, and acetylation. Furthermore, after 48 h, there were 744 genes significantly up-regulated, and 624 genes significantly down-regulated (p‹ 0.01). These genes fell into the following neurological and biological annotation groups: Nervous system development, proteinaceous extracellular matrix, signaling pathways regulating pluripotency of stem cells, cellular function and signal transduction, and apoptosis. We have also noticed that the up-regulated groups contained neuronal cell development, nervous system development, and metabolic processes. In contrast, the down-regulated groups contained many chromosomes and cell cycle categories.

CONCLUSIONS

The effects of BoNT/A on neuronal cells extend beyond blocking the neurotransmitter release, and that BoNT/A is a multifunctional molecule that can evoke profound cellular responses which warrant a more in-depth understanding of the mechanism of the toxin's effects after administration.

Appropriate Timing of Early Postoperative Botulinum Toxin Type A Injection for Thyroidectomy Scar Management: A Split-Scar Study

BACKGROUND

Botulinum toxin type A (BTxA) injection is effective for surgical scar prevention. Although some studies have aimed to confirm the efficacy of BTxA injection at different time points, none has been conducted to determine the most appropriate timing of injection for scar management. The authors predicted that the injection of BTxA at different times during the wound healing process would cause differing scar quality improvement and clarify unknown molecular mechanisms.

METHODS

The study included adults who underwent thyroidectomy. All patients received paralesional BTxA injections on the day of the surgery on either the right or left side of the operative site. The same dose was injected on the noninjected side by means of the same method after 2 weeks. At 2, 4, 12, and 24 weeks postoperatively, the modified Stony Brook Scar Evaluation Scale, visual analogue scale, and erythema index were used for objective, subjective, and quantitative evaluations of the scar. At week 24 postoperatively, a quantitative scar assessment was performed with respect to the erythema index, skin elasticity, melanin index, and friction.

RESULTS

On objective evaluation of the scar and patient satisfaction at 24 weeks postoperatively, the operation-day injection side showed better outcomes than the 2-week-postoperative injection side. These differences were significant from postoperative week 4. In the final quantitative scar assessment at postoperative week 24, significant improvements were observed in the erythema index and skin elasticity.

CONCLUSION

These results suggest that immediate postoperative BTxA injection is more effective for thyroidectomy scar management in terms of erythema, skin elasticity, and patient satisfaction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Botulinum Toxin A Injection for Treatment of Chronic Skin Ulcer: A Case Series and Literature Review

Chronic skin ulcer (CSU) often combines with a variety of refractory factors that respond poorly to routine treatments. Botulinum toxin A (BTX-A) can be injected subcutaneously to improve the local blood supply, to reduce pain, and to promote wound healing. At present, few reports have mentioned BTX-A injection for chronic skin ulcer treatment. We observed the effect of four cases that used BTX-A to treat CSU and provided a brief review of the literature. Four cases of CSUs with 4 different causes were treated with BTX-A injection (4 U/cm²). The specific operation is as follows: local, multipoint, cyclic, equidistant, and subcutaneous injections with a depth of 6 to 8 mm. The ulcer area was significantly reduced. Subsequently, the ulcer healed within 20 to 48 days. Botulinum toxin A is recommended as an important treatment for chronic skin ulcer that can improve healing of skin ulcers with various etiologies.

Efficacy and possible mechanisms of botulinum toxin treatment of oily skin

BACKGROUND

Oily skin is one of the most common dermatological complaints. Oily skin may be accompanied by enlarged pores, acne, and seborrheic dermatitis. Moreover, oily skin has negative effects on self-perception. Most therapeutic approaches used to treat oily skin have had varying degrees of efficacy and include topical treatments, such as photodynamic therapy and lasers. However, certain of these therapies for oily skin may lead to severe side effects. With the expanding use and high safety profile of botulinum toxin type A (BoNT-A), its use in the treatment of oily skin has caused significant concerns; moreover, relevant reports have gradually accumulated to address the efficacy of BoNT-A and explore its mechanisms of action.

AIMS

The objective of this article was to review the efficacy and possible treatment mechanisms of BoNT-A on oily skin.

METHODS

A retrospective review of the published data was conducted.

RESULTS

Most studies have suggested that the intradermal injection of BoNT-A decreased sebum production and pore size. Furthermore, this treatment attained high patient satisfaction without significant side effects. BoNT-A effectively decreased sebum production and excretion, which was in keeping with previous studies, possibly via its blockade of cholinergic signaling and its neuromodulatory effects.

CONCLUSIONS

Intradermal BoNT-A injection may represent a promising new treatment for oily skin and other relevant dermatological problems, such as enlarged pores, acne, and seborrheic dermatitis. Further study is still needed to determine the specific mechanisms of BoNT-A and the optimal injection techniques and doses for oily skin and other relevant cosmetic concerns.

A Randomized, Placebo-Controlled, Double-Blind, Prospective Clinical Trial of Botulinum Toxin Type A in Prevention of Hypertrophic Scar Development in Median Sternotomy Wound

BACKGROUND

Linear hypertrophic scar is a common surgical problem that can be difficult to manage, especially for the median sternotomy scar. Botulinum toxin type A (BTA) is widely used in cosmetic surgery and has been shown to improve scar quality recently. The aim of this study was to evaluate the efficacy of BTA injected in the early postoperative of median sternotomy on preventing scar formation.

METHODS

In this prospective randomized controlled trial, 19 consecutive patients who underwent median sternotomy were enrolled. The median sternotomy wound in each patient was divided into the upper half and the lower half. Both halves of the wound were randomized to receive the treatment with either BTA or normal saline. At 6-month follow-up, scars were assessed using the Vancouver Scar Scale, scar widths were measured, and patients were asked to evaluate their overall satisfaction.

RESULTS

Seventeen patients with median sternotomy wounds completed the entire study. At 6-month follow-up, the mean Vancouver Scar Scale score for the BTA-treated group was 3.44 ± 1.68 and for the normal saline control group was 6.29 ± 2.39, and there was a statistically significant difference between the two groups (P < 0.05). There were also significant improvements in scar width and patient satisfaction for the BTA-treated halves of the wounds (P < 0.05).

CONCLUSIONS

The study demonstrates that early postoperative BTA injection can decrease scar formation and reduce scar width in median sternotomy wounds, and the overall appearance is more satisfactory.

LEVEL OF EVIDENCE I

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The application of W-plasty combined Botox-A injection in treating sunk scar on the face

This study was aimed to explore the effect of W-plasty combined Botox-A injection in improving appearance of scar.According to the inclusive and exclusive criteria, patients received W-plasty combined Botox-A injection (study group) or traditional (control group) scar repairment were enrolled in this study. After surgery, a follow-up ranged from 1 to 2 years was conducted. The effectiveness of surgery was assessed by visual analogue scale (VAS).A total of 38 patients were enrolled in this study, including 21 cases in the study group and 17 cases in the control group. There were no significant difference were identified in age (t = 0.339, P = .736), gender ratio (χ = 0.003, P = .955) and scar forming reason (χ = 0.391, P = .822) between 2 groups. After treatment, the VAS score in the study group was significantly higher than that in the control group (P < .001).W-plasty combined Botox-A injection can significantly improve the appearance of sunk scar on the face.

Botulinum Toxin A: Dose-dependent Effect on Reepithelialization and Angiogenesis

Background:

Botulinum (neuro)toxin A (BoNT) is widely used in the field of plastic and reconstructive surgery. Among treatment of pain, hyperhidrosis, or aesthetic purposes, it is also used to enhance wound healing and prevent excessive scar formation. Some clinical data already exist, but only little is known on a cellular level. The aim of this study was to evaluate the effect of BoNT on cells essential for wound healing in vitro. Therefore, primary human keratinocytes and endothelial cells were treated with different concentrations of BoNT and tested on proliferation, migration, and angiogenic behavior.

Methods:

BoNT was exposed to human keratinocytes and endothelial cells in a low (1 IU/mL), medium (10 IU/mL), and high (20 IU/mL) concentrations in cell culture. Proliferation and migration of the 2 cell types were observed and also the angiogenic potential of endothelial cells in vitro.

Results:

BoNT 20 IU/mL negatively influenced proliferation and migration of keratinocytes but not those of endothelial cells. Angiogenesis in vitro was less effective with the highest BoNT concentrations tested. Low concentrations of BoNT supported sprouting of endothelial cells.

Conclusions:

High concentrations of botulinum toxin interfered with wound closure as keratinocytes’ proliferation and migration were deteriorated. Furthermore, BoNT concentrations of 20 IU/mL constrain in vitro vessel formation but do not influence proliferation or migration of endothelial cells.

The Efficacy and Safety of Fractional CO₂ Laser Combined with Topical Type A Botulinum Toxin for Facial Rejuvenation: A Randomized Controlled Split-Face Study

Objective. We evaluated synergistic efficacy and safety of combined topical application of Botulinum Toxin Type A (BTX-A) with fractional CO₂ laser for facial rejuvenation. Methods. Twenty female subjects were included for this split-face comparative study. One side of each subject's cheek was treated with fractional CO₂ plus saline solution, and the other side was treated with fractional CO₂ laser plus topical application of BTX-A. Patients received one session of treatment and evaluations were done at baseline, one, four, and twelve weeks after treatment. The outcome assessments included subjective satisfaction scale; blinded clinical assessment; and the biophysical parameters of roughness, elasticity, skin hydration, transepidermal water loss (TEWL), and the erythema and melanin index. Results. BTX-A combined with fractional CO₂ laser sides showed higher physician's global assessment score, subject satisfaction score, roughness, skin hydration, and skin elasticity compared to that of fractional CO₂ plus saline solution side at 12 weeks after treatment. TEWL and erythema and melanin index showed no significant differences between two sides at baseline, one, four, and twelve weeks after treatment. Conclusion. Topical application of BTX-A could enhance the rejuvenation effect of fractional CO₂ laser.

Botulinum Toxin Type A and the Prevention of Hypertrophic Scars on the Maxillofacial Area and Neck: A Meta-Analysis of Randomized Controlled Trials

Background

The purpose of the meta-analysis was to evaluate the efficiency of therapeutic botulinum toxin type A (BTX-A) in the prevention of maxillofacial and neck scars.

Methods and Findings

Information came from the following electronic databases: Medline, PubMed, Cochrane Library, and EMBASE (time was ended by August 31, 2015) to retrieve RCTs evaluating the effect of the BTX-A for hypertrophic scar on the maxillofacial or neck. All languages were included as long as they met the inclusion criteria. Here the effects of BTX-A were evaluated by comparing the width of the scar, patient satisfaction, and the visual analysis scores (VAS), respectively. Pooled weighted mean differences (WMDs), pooled odds ratios (ORs), and 95% confidence intervals (CI) were calculated. Nine RCTs covering a total of 539 patients were included. A statistically significant difference in scar width was identified between the BTX-A group and control group (non-BTX-A used) (WMD = -0.41, 95% CI = -0.68 to -0.14, P = 0.003). A statistically significant difference in patient satisfaction was observed between the BTX-A group and control group (OR = 25.76, 95% CI = 2.58 to 256.67, P = 0.006). And in patients regarding visual analysis scores (VAS), a statistically significant difference was also observed between the BTX-A group and control group (WMD = 1.30, 95% CI = 1.00 to 1.60, P < 0.00001).

Conclusions

This meta-analysis evaluates the efficacy of the BTX-A and confirms that BTX-A is a suitable potential therapy for the prevention of hypertrophic scars in patients in the maxillofacial and neck areas.

Botulinum toxin A and lidocaine have an impact on adipose-derived stem cells, fibroblasts, and mature adipocytes in vitro

Lipofilling with autologous fat tissue is widely used in plastic and reconstructive surgery to treat soft-tissue deficiency. Unfortunately, implanted cells disappear gradually and make it difficult to predict the resorption rate. Several adjuvants are used to improve the success of fat tissue grafting. In this study, the effect of botulinum toxin (BoNT) on mature adipocytes, as well as adipose-derived stem cells (ASC) and fibroblasts was evaluated. As lidocaine is the most prevalent drug to anesthetize the donor site as well as the area to be treated with autologous fat, this local anesthetic was examined too. Primary ASCs, fibroblasts, and mature adipocytes were exposed to 1, 10, and 20 IU/ml BoNT A and 1% lidocaine. Cells were tested on proliferation, viability, and LDH release. Adipogenic differentiation potential was evaluated by quantitative real-time PCR analyzing the expression of FABP4. BoNT had no significant influence on the proliferation or viability of tested cells. By trend, low concentrations of BoNT improved adipogenic potential of ASCs. Lidocaine had a strong diminishing effect on the proliferation of ASCs and fibroblasts and on the viability of these cells. Mature adipocytes show no significant inferior viability after BoNT or lidocaine treatment. BoNT has no negative effect on ASCs, mature adipocytes, or fibroblasts in vitro. Lidocaine (1%) negatively influences the proliferation and viability of fibroblasts and partly of ASCs but not of mature adipocytes.