A dose-response study of nanosecond electric energy pulses on facial skin.

Nanosecond pulsed electric fields, also known as Nano-Pulse Stimulation or NPS, can trigger regulated cell death to clear skin lesions that are cellular in nature. Before treating facial lesions, it is important to demonstrate the effects of these pulses on normal facial skin. Here we have applied a range of NPS energies to the epidermis and dermis of normal facial skin scheduled for excision to establish a safe dose range of energies prior to use in clinical applications. This was an open-label, non-randomized study under the direction of a single Principal Investigator. The time course of the treated tissue changes was determined by histological analysis. All energy settings generated a delayed epidermal loss followed by re-epithelialization by day 7 and a normal course of healing. One day after NPS treatment, the cellular membranes of the treated epidermis were intact, but their nuclei no longer stained with H&E, resulting in a hollow appearance that has been referred to as "ghost cells." Cellular structures in the dermis, such as sebaceous glands and melanocytes, exhibited regulated cell death observed by 1 day post treatment. Melanocytes recovered to their normal density within 7 days. The 60-day samples indicated that epidermis, hair follicles, and eccrine glands appeared normal. The selective effect of NPS treatment on cellular structures in the epidermal and dermal layers suggests that this non-thermal modality of energy delivery is ideal for treating cellular targets including benign and malignant skin lesions. NPS skin treatments provide a promising method for clearing skin lesions with a cellular basis.

A dose-response study of a novel method of selective tissue modification of cellular structures in the skin with nanosecond pulsed electric fields.

BACKGROUND AND OBJECTIVES: This study describes the effects of nanosecond pulsed electric fields (nsPEF) on the epidermis and dermis of normal skin scheduled for excision in a subsequent abdominoplasty. NsPEF therapy applies nanosecond pulses of electrical energy to induce regulated cell death (RCD) in cellular structures, with negligible thermal effects. Prior pre-clinical studies using nsPEF technology have demonstrated the ability to stimulate a lasting immune response in animal tumor models, including melanoma. This first-in-human-use of nsPEF treatment in a controlled study to evaluate the dose-response effects on normal skin and subcutaneous structures is intended to establish a safe dose range of energies prior to use in clinical applications using nsPEF for non-thermal tissue modification. STUDY DESIGN/MATERIALS AND METHODS: Seven subjects with healthy tissue planned for abdominoplasty excision were enrolled. Five subjects were evaluated in a longitudinal, 60-day study of effects with doses of six nsPEF energy levels. A total of 30 squares of spot sizes 25mm2 or less within the planned excision area were treated and then evaluated at 1 day, 5 days, 15 days, 30 days, and 60 days prior to surgery. Photographs were taken over time of each treated area and assessed by three independent and blinded dermatologists for erythema, flaking and crusting using a 5-point scale (0 = low, 4 = high). Punch biopsies of surgically removed tissue were processed and evaluated for tissue changes using hematoxylin and eosin, trichome, caspase-3, microphthalmia transcription factor, and elastin stains and evaluated by a dermatopathologist. The skin of two subjects received additional treatments at 2 and 4 hours post-nsPEF and was evaluated in a similar manner. RESULTS: Most energy settings exhibited delayed epidermal loss followed by re-epithelization by day 15 and a normal course of healing. Histologic analysis identified the appearance of activated caspase-3 at two and four hours after nsPEF treatment, but not at later time points. At the 1-day time point, a nucleolysis effect was observed in epidermal cells, as evidenced by the lack of nuclear staining while the epidermal plasma membranes were still intact. Cellular structures within the treatment zone such as melanocytes, sebaceous glands, and hair follicles were damaged while acellular structures such as elastic fibers and collagen were largely unaffected except for TL6 which showed signs of dermal damage. Melanocytes reappeared at levels comparable with untreated controls within 1 month of nsPEF treatment. CONCLUSIONS: The selective effect of nsPEF treatment on cellular structures in the epidermal and dermal layers suggests that this non-thermal mechanism for targeting cellular structures does not affect the integrity of dermal tissue within a range of energy levels. The specificity of effects and a favorable healing response makes nsPEF ideal for treating cellular targets in the epidermal or dermal layers of the skin, including treatment of benign and malignant lesions. NsPEF skin treatments provide a promising, non-thermal method for treating skin conditions and removing epidermal lesions. © 2019 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Safety and Efficacy of Nanosecond Pulsed Electric Field Treatment of Seborrheic Keratoses.

BACKGROUND: Nanosecond pulsed electric field technology (also known as Nano-Pulse Stimulation or NPS) is a nonthermal, drug-free, energy-based technology that has demonstrated effects on cellular structures of the dermis and epidermis in previous clinical studies. OBJECTIVE: To evaluate the safety and efficacy of a single NPS treatment for clearing seborrheic keratoses (SKs). MATERIALS AND METHODS: This study was a prospective, randomized, open-label, multisite, nonsignificant risk trial in which each subject served as their own control. Fifty-eight subjects had 3 of 4 confirmed SK lesions treated, resulting in 174 total treated lesions. Subjects returned for 5 to 6 follow-up evaluations and photographs. RESULTS: At 106 days after NPS treatment, 82% of treated seborrheic keratoses were rated clear or mostly clear by the assessing physician. Seventy-one percent of lesions were rated clear or mostly clear by the 3 independent reviewers based on the 106-day photographs. All treated subjects returned for all study visits, and 78% of the subjects were satisfied or mostly satisfied with the outcome of the treatment. No adverse events were reported. CONCLUSION: The NPS procedure was well tolerated and effective in the removal of SKs.

Safety and Efficacy of Nanosecond Pulsed Electric Field Treatment of Sebaceous Gland Hyperplasia.

BACKGROUND: Nanosecond pulsed electric field (nsPEF) technology involves delivery of ultrashort pulses of electrical energy and is a nonthermal, drug-free technology that has demonstrated favorable effects on cellular structures of the dermis and epidermis. OBJECTIVE: Determine the tolerability and effectiveness of nsPEF treatment of sebaceous gland hyperplasia (SGH). METHODS: This study was a prospective, randomized, open-label, multisite, nonsignificant risk trial in which each subject served as their own control. After injection of local anesthetic, high-intensity, ultrashort pulses of electrical energy were used to treat 72 subjects resulting in a total of 222 treated lesions. Subjects returned for 3 to 4 follow-up evaluations with photographs. RESULTS: At the final study visit, 99.6% of treated SGH lesions were rated clear or mostly clear and 79.3% of the subjects were satisfied or mostly satisfied with the outcome. At 60 days after nsPEF treatment, 55% of the lesions were judged to have no hyperpigmentation and 31% exhibited mild post-treatment hyperpigmentation. At the last observation for all lesions, 32% of the 222 lesions were noted as having slight volume loss. CONCLUSION: Nanosecond pulsed electric field procedure is well tolerated and is very effective in the removal of SGHs. TRIAL REGISTRATION: ClinicalTrials.gov NCT03612570.