Selective reduction of visceral adipose tissue with injectable ice slurry.

Reduction in visceral adipose tissue (VAT) mass reduces body weight and metabolic disease risk in obese patients. However surgical removal of VAT is highly invasive and thus not clinically feasible. We developed an injectable ice slurry for selective reduction of adipose tissue through cryolipolysis. The aim of this study was to investigate safety, feasibility and mechanism of ice slurry-induced cryolipolysis of VAT. Perigonadal VAT in diet-induced obese mice and rats was subjected to slurry or sham treatment. Body weight and blood chemistry were monitored for 56 days post-treatment. Histological analysis and molecular studies were performed to elucidate mechanisms of fat reduction. Treatment of VAT was well tolerated in all animals. Slurry induced adipocyte cell death via selective cryolipolysis; significant weight loss was noted at day 21 post-treatment. RNA sequencing from treated VAT samples showed increased expression of genes involved in inflammation, immune response, collagen biosynthesis and wound healing, and decreased expression of adipokines. This study demonstrates that slurry treatment is safe and effective in inducing cryolipolysis of VAT and subsequent weight loss in mice. Ice slurry is promising as a minimally-invasive treatment to reduce visceral adipose tissue.

Veno-venous extracorporeal blood phototherapy increases the rate of carbon monoxide (CO) elimination in CO-poisoned pigs.

BACKGROUND AND OBJECTIVES: Carbon monoxide (CO) inhalation is the leading cause of poison-related deaths in the United States. CO binds to hemoglobin (Hb), displaces oxygen, and reduces oxygen delivery to tissues. The optimal treatment for CO poisoning in patients with normal lung function is the administration of hyperbaric oxygen (HBO). However, hyperbaric chambers are only available in medical centers with specialized equipment, resulting in delayed therapy. Visible light dissociates CO from Hb with minimal effect on oxygen binding. In a previous study, we combined a membrane oxygenator with phototherapy at 623 nm to produce a "mini" photo-ECMO (extracorporeal membrane oxygenation) device, which improved CO elimination and survival in CO-poisoned rats. The objective of this study was to develop a larger photo-ECMO device ("maxi" photo-ECMO) and to test its ability to remove CO from a porcine model of CO poisoning. STUDY DESIGN/MATERIALS AND METHODS: The "maxi" photo-ECMO device and the photo-ECMO system (six maxi photo-ECMO devices assembled in parallel), were tested in an in vitro circuit of CO poisoning. To assess the ability of the photo-ECMO device and the photo-ECMO system to remove CO from CO-poisoned blood in vitro, the half-life of COHb (COHb-t1/2 ), as well as the percent COHb reduction in a single blood pass through the device, were assessed. In the in vivo studies, we assessed the COHb-t1/2 in a CO-poisoned pig under three conditions: (1) While the pig breathed 100% oxygen through the endotracheal tube; (2) while the pig was connected to the photo-ECMO system with no light exposure; and (3) while the pig was connected to the photo-ECMO system, which was exposed to red light. RESULTS: The photo-ECMO device was able to fully oxygenate the blood after a single pass through the device. Compared to ventilation with 100% oxygen alone, illumination with red light together with 100% oxygen was twice as efficient in removing CO from blood. Changes in gas flow rates did not alter CO elimination in one pass through the device. Increases in irradiance up to 214 mW/cm2 were associated with an increased rate of CO elimination. The photo-ECMO device was effective over a range of blood flow rates and with higher blood flow rates, more CO was eliminated. A photo-ECMO system composed of six photo-ECMO devices removed CO faster from CO-poisoned blood than a single photo-ECMO device. In a CO-poisoned pig, the photo-ECMO system increased the rate of CO elimination without significantly increasing the animal's body temperature or causing hemodynamic instability. CONCLUSION: In this study, we developed a photo-ECMO system and demonstrated its ability to remove CO from CO-poisoned 45-kg pigs. Technical modifications of the photo-ECMO system, including the development of a compact, portable device, will permit treatment of patients with CO poisoning at the scene of their poisoning, during transit to a local emergency room, and in hospitals that lack HBO facilities.

Laser Treatment of Traumatic Scars and Contractures: 2020 International Consensus Recommendations.

BACKGROUND AND OBJECTIVES: There is currently intense multidisciplinary interest and a maturing body of literature regarding laser treatments for traumatic scars, but international treatment guidelines and reimbursement schemes have not yet caught up with current knowledge and practice in many centers. The authors intend to highlight the tremendous potential of laser techniques, offer recommendations for safe and efficacious treatment, and promote wider patient access guided by future high-quality research. STUDY DESIGN/MATERIALS AND METHODS: An international panel of 26 dermatologists and plastic and reconstructive surgeons from 13 different countries and a variety of practice backgrounds was self-assembled to develop updated consensus recommendations for the laser treatment of traumatic scars. A three-step modified Delphi method took place between March 2018 and March 2019 consisting of two rounds of emailed questionnaires and supplementary face-to-face meetings. The panel members approved the final manuscript via email correspondence, and the threshold for consensus was at least 80% concurrence among the panel members. RESULTS: The manuscript includes extensive detailed discussion regarding a variety of laser platforms commonly used for traumatic scar management such as vascular lasers and ablative and non-ablative fractional lasers, special considerations such as coding and laser treatments in skin of color, and 25 summary consensus recommendations. CONCLUSIONS: Lasers are a first-line therapy in the management of traumatic scars and contractures, and patients without access to these treatments may not be receiving the best available care after injury. Updated international treatment guidelines and reimbursement schemes, additional high-quality research, and patient access should reflect this status. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Laser-assisted delivery of synergistic combination chemotherapy in in vivo skin.

The effectiveness of topical drugs for treatment of non-melanoma skin cancer is greatly reduced by insufficient penetration to deep skin layers. Ablative fractional lasers (AFLs) are known to enhance topical drug uptake by generating narrow microchannels through the skin, but information on AFL-drug delivery in in vivo conditions is limited. In this study, we examined pharmacokinetics, biodistribution and toxicity of two synergistic chemotherapy agents, cisplatin and 5-fluorouracil (5-FU), following AFL-assisted delivery alone or in combination in in vivo porcine skin. Detected at 0-120 h using mass spectrometry techniques, we demonstrated that fractional CO2 laser pretreatment (196 microchannels/cm2, 852 µm ablation depth) leads to rapid drug uptake in 1500 µm deep skin layers, with a sixfold enhancement in peak cisplatin concentrations versus non-laser-treated controls (5 h, P = 0.005). Similarly, maximum 5-FU deposition was measured within an hour of AFL-delivery, and exceeded peak deposition in non-laser-exposed skin that had undergone topical drug exposure for 5 days. Overall, this accelerated and deeper cutaneous drug uptake resulted in significantly increased inflammatory and histopathological effects. Based on clinical scores and transepidermal water loss measurement, AFL intensified local toxic responses to drugs delivered alone and in combination, while systemic drug exposure remained undetectable. Quantitative histopathologic analyses correspondingly revealed significantly reduced epidermal proliferation and greater cellular apoptosis after AFL-drug delivery; particularly after combined cisplatin + 5-FU exposure. In sum, by overcoming the primary limitation of topical drug penetration and providing accelerated, enhanced and deeper delivery, AFL-assisted combination chemotherapy may represent a promising treatment strategy for non-melanoma skin cancer.

Transient Alterations of Cutaneous Sensory Nerve Function by Noninvasive Cryolipolysis.

Cryolipolysis is a noninvasive, skin cooling treatment for local fat reduction that causes prolonged hypoesthesia over the treated area. We tested the hypothesis that cryolipolysis can attenuate nociception of a range of sensory stimuli, including stimuli that evoke itch. The effects of cryolipolysis on sensory phenomena were evaluated by quantitative sensory testing (QST) in 11 healthy subjects over a period of 56 days. Mechanical and thermal pain thresholds were measured on treated and contralateral untreated (control) flanks. Itch duration was evaluated following histamine iontophoresis. Unmyelinated epidermal nerve fiber and myelinated dermal nerve fiber densities were quantified in skin biopsies from six subjects. Cryolipolysis produced a marked decrease in mechanical and thermal pain sensitivity. Hyposensitivity started between two to seven days after cryolipolysis and persisted for at least thirty-five days post treatment. Skin biopsies revealed that cryolipolysis decreased epidermal nerve fiber density, as well as dermal myelinated nerve fiber density, which persisted throughout the study. In conclusion, cryolipolysis causes significant and prolonged decreases in cutaneous sensitivity. Our data suggest that controlled skin cooling to specifically target cutaneous nerve fibers has the potential to be useful for prolonged relief of cutaneous pain and might have a use as a research tool to isolate and study cutaneous itch-sensing nerves in human skin.

Selective Cryolysis of Sebaceous Glands.

Acne vulgaris is a nearly universal cutaneous inflammatory disease. Excess sebum production is an integral part of disease pathogenesis. Medical therapies that reduce sebum excretion result in clinical improvement of acne. Given the preferential susceptibility of lipid-containing cells to cold, we investigated the hypothesis that controlled local skin cooling causes preferential injury to sebaceous glands, in murine and swine models using a range of temperatures as low as -10 °C, and then on the backs of human subjects. In mouse ears, peak histologic damage occurred 72 hours after treatment; eosinophilic necrotic plugs formed within sebaceous glands, and the number of glands was significantly reduced up to 1 week post treatment. Cooling disrupted sebocyte cell membranes, alkaline phosphatase activity, and significantly reduced sebocyte lipid content. In human volunteers, cooling damaged sebaceous glands and reduced sebum output for 2 weeks, with minimal injury to surrounding tissues. Selective cryolysis of sebaceous glands is achievable through brief, non-invasive skin cooling, suggesting that controlled cooling could be developed as an effective treatment for acne vulgaris.

Longitudinal, 3D in vivo imaging of sebaceous glands by coherent anti-stokes Raman scattering microscopy: normal function and response to cryotherapy.

Sebaceous glands perform complex functions, and they are centrally involved in the pathogenesis of acne vulgaris. Current techniques for studying sebaceous glands are mostly static in nature, whereas the gland's main function-excretion of sebum via the holocrine mechanism-can only be evaluated over time. We present a longitudinal, real-time alternative-the in vivo, label-free imaging of sebaceous glands using Coherent Anti-Stokes Raman Scattering (CARS) microscopy, which is used to selectively visualize lipids. In mouse ears, CARS microscopy revealed dynamic changes in sebaceous glands during the holocrine secretion process, as well as in response to damage to the glands caused by cooling. Detailed gland structure, plus the active migration of individual sebocytes and cohorts of sebocytes, were measured. Cooling produced characteristic changes in sebocyte structure and migration. This study demonstrates that CARS microscopy is a promising tool for studying the sebaceous gland and its associated disorders in three dimensions in vivo.

Endovenous laser ablation: mechanism of action.

OBJECTIVES: The objective of this study is to review the basics of laser and established tissue response patterns to thermal injury, with specific reference to endovenous laser ablation (EVLA). This study also reviews the current theories and supporting aspects for the mechanism of action of EVLA in the treatment of superficial venous reflux. METHODS: The method involves the review of published literature and original investigation of histological effects of 810 nm and 980 nm wavelength EVLA on explanted blood-filled bovine saphenous vein in an in vitro system. RESULTS: The existing histological reports confirm that EVLA produces a transmural vein wall injury, typically associated with perforations and carbonization. The pattern of injury is eccentrically distributed, with maximum injury occurring along the path of laser contact. Intravenous temperature monitoring studies during EVLA have confirmed that the peak temperatures at the fibre tip exceed 1000 degrees C, and continuous temperatures of at least 300 degrees C are maintained in the firing zone for the majority of the procedure. Steam production during EVLA, which occurs early in the photothermolytic process when temperatures reach 100 degrees C, accounts for only 2% of applied energy dose, and is therefore unlikely to be the primary mechanism of action of thermal injury during the procedure. CONCLUSION: EVLA causes permanent vein closure through a high-temperature photothermolytic process at the point of contact between the vein and the laser.

Laser-beam-triggered microcavitation: a novel method for selective cell destruction.

We describe a new method of cell destruction that may have potential for use in antitumor therapy. Cells are loaded by phagocytosis with microparticles (<1 microm) and irradiated with short laser pulses. Absorption of laser energy by the microparticles causes localized vaporization of the fluid surrounding the microparticles, leading to the generation of transient vapor bubbles (microcavitation) around the microparticles. Using cultures of bovine aortic endothelial cells, we demonstrate that induction of intralysosomal microcavitation is an efficient, rapid and selective method of cell killing that is dependent on the number of microparticles, the number of laser pulses, and the fluence of the laser pulses. Cell killing by microcavitation is a very selective process that is restricted to cells containing microparticles, leaving other cells unaffected. Intracytoplasmic release of lysosomal hydrolases is, in part, responsible for cell death, because the protease inhibitors E64d and TLCK diminished cell killing. Using the broad-specificity caspase inhibitor Z-VAD-fmk, we determined that lysosomal hydrolases could induce apoptosis in a caspase-independent manner. We also examined the possibility of microcavitation-induced delayed effects in the cells that survived the treatment. Using flow cytometry, we determined that there was no delayed cell death between 1 and 4 days after microcavitation. Moreover, we did not observe changes in the cell cycle, in expression of the proteins BCL2, HSP70 and HSP27, or in PARP degradation. In conclusion, microcavitation induces rapid and specific cells death (limited only to cells containing microparticles), without producing delayed effects among the surviving cells.