The Yucatan miniature swine as a model for post-inflammatory hyperpigmentation

Post-inflammatory hyperpigmentation (PIH) is a hypermelanosis that often occurs secondary to skin irritation or injury, especially in darker skin tones, for which there is currently a lack of effective treatment options. Few preclinical models are available to study PIH. Here, we show that the Yucatan miniature pig consistently develops PIH after skin injuries. Skin wounds were produced on Yucatan pigs by needle punches, full-thickness excisions, or burns. Wound sites were monitored and photographed regularly. Tissue samples were collected after 24 weeks and processed for histology/immunohistochemistry. Skin pigmentation and histologic changes were quantified by computer-assisted image analyses. All injury methods resulted in hyperpigmentation. Melanin content at the histologic level was quantified in the larger (burn and excision) wounds, showing a significant increase compared to uninjured skin. Increased melanin was found for both epidermal and dermal regions. Dermal melanin deposits were primarily clustered around the papillary vasculature, and were associated not with melanocytes but with leukocytes. The Yucatan miniature pig model recapitulates key clinical and histologic features of PIH in humans, including skin hyperpigmentation at both gross and histologic levels, and persistence of dermal melanin subsequent to injury. This model could be used to further our understanding of the etiology of PIH, and for new therapy development.

Increased susceptibility to ischemia causes exacerbated response to microinjuries in the cirrhotic liver

Fractional laser ablation is a technique developed in dermatology to induce remodeling of skin scars by creating a dense pattern of microinjuries. Despite remarkable clinical results, this technique has yet to be tested for scars in other tissues. As a first step toward determining the suitability of this technique, we aimed to (1) characterize the response to microinjuries in the healthy and cirrhotic liver, and (2) determine the underlying cause for any differences in response. Healthy and cirrhotic rats were treated with a fractional laser then euthanized from 0 h up to 14 days after treatment. Differential expression was assessed using RNAseq with a difference-in-differences model. Spatial maps of tissue oxygenation were acquired with hyperspectral imaging and disruptions in blood supply were assessed with tomato lectin perfusion. Healthy rats showed little damage beyond the initial microinjury and healed completely by 7 days without scarring. In cirrhotic rats, hepatocytes surrounding microinjury sites died 4-6 h after ablation, resulting in enlarged and heterogeneous zones of cell death. Hepatocytes near blood vessels were spared, particularly near the highly vascularized septa. Gene sets related to ischemia and angiogenesis were enriched at 4 h. Laser-treated regions had reduced oxygen saturation and broadly disrupted perfusion of nodule microvasculature, which matched the zones of cell death. Our results demonstrate that the cirrhotic liver has an exacerbated response to microinjuries and increased susceptibility to ischemia from microvascular damage, likely related to the vascular derangements that occur during cirrhosis development. Modifications to the fractional laser tool, such as using a femtosecond laser or reducing the spot size, may be able to prevent large disruptions of perfusion and enable further development of a laser-induced microinjury treatment for cirrhosis.

Noninvasive treatment of cutaneous neurofibromas (cNFs): Results of a randomized prospective, direct comparison of four methods

BACKGROUND

People with Neurofibromatosis Type 1 (NF1) suffer disfigurement and pain when hundreds to thousands of cutaneous neurofibromas (cNFs) appear and grow throughout life. Surgical removal of cNFs under anesthesia is the only standard therapy, leaving surgical scars.

OBJECTIVE

Effective, minimally-invasive, safe, rapid, tolerable treatment(s) of small cNFs that may prevent tumor progression.

METHODS

Safety, tolerability, and efficacy of 4 different treatments were compared in 309, 2-4 mm cNFs across 19 adults with Fitzpatrick skin types (FST) I-IV: radiofrequency (RF) needle coagulation, 755 nm alexandrite laser with suction, 980 nm diode laser, and intratumoral injection of 10 mg/mL deoxycholate. Regional pain, clinical responses, tumor height and volume (by 3D photography) were assessed before, 3 and 6 months post-treatment. Biopsies were obtained electively at 3 months.

RESULTS

There was no scarring or adverse events > grade 2. Each modality significantly (P < .05) reduced or cleared cNFs, with large variation between tumors and participants. Alexandrite laser and deoxycholate were fast and least painful; 980 nm laser was most painful. Growth of cNFs was not stimulated by treatment(s) based on height and volume values at 3 and 6 months compared to baseline.

LIMITATIONS

Intervention was a single treatment session; dosimetry has not been optimized.

CONCLUSIONS

Small cNFs can be rapidly and safely treated without surgery.

Autofluorescence Excitation Imaging of Nonmelanoma Skin Cancer for Margin Assessment Before Mohs Micrographic Surgery: A Pilot Study

BACKGROUND

Autofluorescence photography can detect specific light-tissue interactions and record important pathophysiological changes associated with nonmelanoma skin cancer (NMSC), which has been ascribed to the fluorescence of an aromatic amino acid, tryptophan.

OBJECTIVE

To assess the impact of a novel, autofluorescence imaging (AFI) device on margin control for NMSCs before Mohs micrographic surgery (MMS) in an effort to decrease overall operating time.

METHODS

Before the initial stage of MMS, NMSCs were measured with a 2-mm margin as standard of care (normal margin). The tumor was then imaged with the AFI device. A 2-mm margin was drawn around the fluorescent area captured by the AFI device and was referred to as the camera margin. The tumor was excised based on the normal margin and evaluated on frozen histological section.

RESULTS

Imaging based on the AFI device resulted in appropriate recommendations for margin control in 8 of 11 tumors. Four of these tumors did not fluoresce and demonstrated a lack of tumor residuum on stage I specimen, as anticipated. There were no side effects from the AFI device.

CONCLUSION

This is an initial pilot study that supports the use of a novel, noninvasive imaging device to help with margin assessment before MMS. On optimization, this device has potential to extend applicability to surgical excisions for tumors that do not fulfill criteria for MMS.

Blue Light Potentiates Antibiotics in Bacteria via Parallel Pathways of Hydroxyl Radical Production and Enhanced Antibiotic Uptake

In the age of antimicrobial resistance, the urgency by which novel therapeutic approaches need to be introduced into the clinical pipeline has reached critical levels. Antimicrobial blue light (aBL), as an alternative approach, has demonstrated promise as a stand-alone therapeutic method, albeit with a limited window of antimicrobial activity. Work by others indicates that treatment with antibiotics increases the production of reactive oxygen species (ROS) which may, in part, contribute to the bactericidal effects of antibiotics. These findings suggest that there may be potential for synergistic interactions with aBL, that similarly generates ROS. Therefore, in this study, the mechanism of aBL is investigated, and the potential for aBL to synergistically promote antibiotic activity is similarly evaluated. Furthermore, the translatability of using aBL and chloramphenicol in combination within a mouse model of Acinetobacter baumanii burn infection is assessed. It is concluded that porphyrins and hydroxyl radicals driven by "free iron" are paramount to the effectiveness of aBL; and aBL is effective at promoting multiple antibiotics in different multidrug-resistant bacteria. Moreover, rROS up-regulation, and promoted antibiotic uptake are observed during aBL+antibiotic exposure. Lastly, aBL combined with chloramphenicol appears to be both effective and safe for the treatment of A. baumannii burn infection. In conclusion, aBL may be a useful adjunct therapy to antibiotics to potentiate their action.

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.

Vitamin K3 (Menadione) is a multifunctional microbicide acting as a photosensitizer and synergizing with blue light to kill drug-resistant bacteria in biofilms

Cutaneous bacterial wound infections typically involve gram-positive cocci such as Staphylococcus aureus (SA) and usually become biofilm infections. Bacteria in biofilms may be 100-1000-fold more resistant to an antibiotic than the clinical laboratory minimal inhibitory concentration (MIC) for that antibiotic, contributing to antimicrobial resistance (AMR). AMR is a growing global threat to humanity. One pathogen-antibiotic resistant combination, methicillin-resistant SA (MRSA) caused more deaths globally than any other such combination in a recent worldwide statistical review. Many wound infections are accessible to light. Antimicrobial phototherapy, and particularly antimicrobial blue light therapy (aBL) is an innovative non-antibiotic approach often overlooked as a possible alternative or adjunctive therapy to reduce antibiotic use. We therefore focused on aBL treatment of biofilm infections, especially MRSA, focusing on in vitro and ex vivo porcine skin models of bacterial biofilm infections. Since aBL is microbicidal through the generation of reactive oxygen species (ROS), we hypothesized that menadione (Vitamin K3), a multifunctional ROS generator, might enhance aBL. Our studies suggest that menadione can synergize with aBL to increase both ROS and microbicidal effects, acting as a photosensitizer as well as an ROS recycler in the treatment of biofilm infections. Vitamin K3/menadione has been given orally and intravenously worldwide to thousands of patients. We conclude that menadione/Vitamin K3 can be used as an adjunct to antimicrobial blue light therapy, increasing the effectiveness of this modality in the treatment of biofilm infections, thereby presenting a potential alternative to antibiotic therapy, to which biofilm infections are so resistant.

Optical, flow, and thermal analysis of a phototherapy extracorporeal membrane oxygenator for treating carbon monoxide poisoning

BACKGROUND

Extracorporeal membrane oxygenators (ECMO) are currently utilized to mechanically ventilate blood when lung or lung and heart function are impaired, like in cases of acute respiratory distress syndrome (ARDS). ARDS can be caused by severe cases of carbon monoxide (CO) inhalation, which is the leading cause of poison-related deaths in the United States. ECMOs can be further optimized for severe CO inhalation using visible light to photo-dissociate CO from hemoglobin (Hb). In previous studies, we combined phototherapy with an ECMO to design a photo-ECMO device, which significantly increased CO elimination and improved survival in CO-poisoned animal models using light at 460, 523, and 620 nm wavelengths. Light at 620 nm was the most effective in removing CO.

OBJECTIVE

The aim of this study is to analyze the light propagation at 460, 523, and 620 nm wavelengths and the 3D blood flow and heating distribution within the photo-ECMO device that increased CO elimination in CO-poisoned animal models.

METHODS

Light propagation, blood flow dynamics, and heat diffusion were modeled using the Monte Carlo method and the laminar Navier-Stokes and heat diffusion equations, respectively.

RESULTS

Light at 620 nm propagated through the device blood compartment (4 mm), while light at 460 and 523 nm only penetrated 48% to 50% (~2 mm). The blood flow velocity in the blood compartment varied with regions of high (5 mm/s) and low (1 mm/s) velocity, including stagnant flow. The blood temperatures at the device outlet for 460, 523, and 620 nm wavelengths were approximately 26.7°C, 27.4°C, and 20°C, respectively. However, the maximum temperatures within the blood treatment compartment rose to approximately 71°C, 77°C, and 21°C, respectively.

CONCLUSIONS

As the extent of light propagation correlates with efficiency in photodissociation, the light at 620 nm is the optimal wavelength for removing CO from Hb while maintaining blood temperatures below thermal damage. Measuring the inlet and outlet blood temperatures is not enough to avoid unintentional thermal damage by light irradiation. Computational models can help eliminate risks of excessive heating and improve device development by analyzing design modifications that improve blood flow, like suppressing stagnant flow, further increasing the rate of CO elimination.

Boot camp: Training and dressing regimens for modeling plantar wounds in the swine

Foot ulceration annually affects millions of patients and accounts for billions of dollars in medical expenses in the US alone. Many previous studies have investigated co-morbidities associated with impaired healing, such as microbial infection, compromised circulation, and diabetes. By comparison, little is known about how wound healing proceeds in plantar skin, despite its many unique specializations related to its load-bearing function. One of the main challenges in modeling plantar wounds is the difficulty in maintaining wound dressings, as animals generally have a low tolerance to wearing bandages on their feet. With assistance from the MGH Center for Comparative Medicine, we developed a positive reinforcement-based behavioral training regimen that successfully induced tolerance for plantar dressings in swine, which is a critical first step towards enabling in vivo study of the wound healing process in this highly specialized skin area. This training program will be described in detail in this manuscript.

Cryoneurolysis with Injectable Ice Slurry Modulates Mechanical Skin Pain

Cutaneous pain is a common symptom of skin disease, and available therapies are inadequate. We developed a neural selective and injectable method of cryoneurolysis with ice slurry, which leads to a long-lasting decrease in mechanical pain. The aim of this study is to determine whether slurry injection reduces cutaneous pain without inducing the side effects associated with conventional cryoneurolysis. Using the rat sciatic nerve, we examined the effects of slurry on nerve structure and function in comparison with the effects of a Food and Drug Administration‒approved cryoneurolysis device (Iovera). Coherent anti-Stokes Raman scattering microscopy and immunofluorescence staining were used to investigate histological effects on the sciatic nerve and on downstream cutaneous nerve fibers. Complete Freund's Adjuvant model of cutaneous pain was used to study the effect of the slurry on reducing pain. Structural changes in myelin induced by slurry were comparable with those induced by Iovera, which uses much colder temperatures. Compared with that of Iovera, the decrease in mechanical pain due to slurry was less profound but lasted longer without signs of dysesthesia. Slurry did not cause a reduction of epidermal nerve fibers or a change in thermal pain sensitivity. Slurry-treated rats showed reduced cutaneous mechanical pain in response to Complete Freund's Adjuvant. Slurry injection can be used to successfully reduce cutaneous pain without causing dysesthesia.

Total ice content and lipid saturation determine adipose tissue cryolipolysis by injection of ice-slurry

OBJECTIVES

Cryolipolysis uses tissue cooling to solidify lipids, preferentially damaging lipid-rich cells. Topical cooling is popular for the reduction of local subcutaneous fat. Injection of biocompatible ice-slurry is a recently introduced alternative. We developed and verified a quantitative model that simulates the heat exchange and phase changes involved, offering insights into ice-slurry injection for treating subcutaneous fat.

METHODS

Finite element method was used to model the spatial and temporal progression of heat transfer between adipose tissue and injected ice-slurry, estimating dose-response relationships between properties of the slurry and size of tissue affected by cryolipolysis. Phase changes of both slurry and adipose tissue lipids were considered. An in vivo swine model was used to validate the numerical solutions. Oils with different lipid compositions were exposed to ice-slurry in vitro to evaluate the effects of lipid freezing temperature. Microscopy and nuclear magnetic resonance (NMR) were performed to detect lipid phase changes.

RESULTS

A ball of granular ice was deposited at the injection site in subcutaneous fat. Total injected ice content determines both the effective cooling region of tissue, and the duration of tissue cooling. Water's high latent heat of fusion enables tissue cooling long after slurry injection. Slurry temperature affects the rate of tissue cooling. In swine, when 30 ml slurry injection at -3.5°C was compared to 15 ml slurry injection at -4.8°C (both with the same total ice content), the latter led to almost twice faster tissue cooling. NMR showed a large decrease in diffusion upon lipid crystallization; saturated lipids with higher freezing temperatures were more susceptible to solidification after ice-slurry injection.

CONCLUSIONS

Total injected ice content determines both the volume of tissue treated by cryolipolysis and the cooling duration after slurry injection, while slurry temperature affects the cooling rate. Lipid saturation, which varies with diet and anatomic location, also has an important influence.

Local vasoregulative interventions impact drug concentrations in the skin after topical laser-assisted delivery

INTRODUCTION

The ability of ablative fractional lasers (AFL) to enhance topical drug uptake is well established. After AFL delivery, however, drug clearance by local vasculature is poorly understood. Modifications in vascular clearance may enhance AFL-assisted drug concentrations and prolong drug dwell time in the skin. Aiming to assess the role and modifiability of vascular clearance after AFL-assisted delivery, this study examined the impact of vasoregulative interventions on AFL-assisted 5-fluorouracil (5-FU) concentrations in in vivo skin.

METHODS

5-FU uptake was assessed in intact and AFL-exposed skin in a live pig model. After fractional CO₂ laser exposure (15 mJ/microbeam, 5% density), vasoregulative intervention using topical brimonidine cream, epinephrine solution, or pulsed dye laser (PDL) was performed in designated treatment areas, followed by a single 5% 5-FU cream application. At 0, 1, 4, 48, and 72 h, 5-FU concentrations were measured in 500 and 1500 μm skin layers by mass spectrometry (n = 6). A supplemental assessment of blood flow following AFL ± vasoregulation was performed using optical coherence tomography (OCT) in a human volunteer.

RESULTS

Compared to intact skin, AFL facilitated a prompt peak in 5-FU delivery that remained elevated up to 4 hours (1500 μm: 1.5 vs. 31.8 ng/ml [1 hour, p = 0.002]; 5.3 vs. 14.5 ng/ml [4 hours, p = 0.039]). However, AFL's impact was transient, with 5-FU concentrations comparable to intact skin at later time points. Overall, vasoregulative intervention with brimonidine or PDL led to significantly higher peak 5-FU concentrations, prolonging the drug's dwell time in the skin versus AFL delivery alone. As such, brimonidine and PDL led to twofold higher 5-FU concentrations than AFL alone in both skin layers by 1 hour (e.g., 500 μm: 107 ng/ml [brimonidine]; 96.9 ng/ml [PDL], 46.6 ng/ml [AFL alone], p ≤ 0.024), and remained significantly elevated at 4 hours (p ≤ 0.024). A similar pattern was observed for epinephrine, although trends remained nonsignificant (p ≥ 0.09). Prolonged 5-FU delivery was provided by PDL, resulting in sustained drug deposition compared to AFL alone at both 48 and 72 hours in the superficial skin layer (p ≤ 0.024). Supporting drug delivery findings, OCT revealed that increases in local blood flow after AFL were mitigated in test areas also exposed to PDL, brimonidine, or epinephrine, with PDL providing the greatest, sustained reduction in flow over 48 hours.

CONCLUSION

Vasoregulative intervention in conjunction with AFL-assisted delivery enhances and prolongs 5-FU deposition in in vivo skin.

Full Recovery after Multiple Treatments with Injectable Ice Slurry

Background

Cryoneurolysis uses tissue cooling as an opioid-sparing, long-lasting treatment for peripheral nerve pain. A nerve-selective method for cryoneurolysis by local injection of ice-slurry was developed to allow cryoneurolysis to be performed with a standard needle and syringe, similar to peripheral nerve blocks. Since the treatment of patients with chronic pain may require repeated injections, we investigated the safety and tolerance of repeated treatments in a rat model.

Methods

Three repeated ice-slurry treatments, given 6 weeks apart were performed around the rat sciatic nerve. Nerve and surrounding tissues were collected up to 4 months after the third treatment for analysis. Coherent anti-Stokes Raman scattering (CARS) microscopy was used to study effects on myelin sheaths and axon structure. Immunofluorescence (IF) staining was used to study effects on axon density. Hematoxylin and Eosin (H&E) staining was used to examine histologic effects on sciatic nerve and surrounding tissue.

Results

Histologic and CARS image analysis of nerve tissue collected months after three injections demonstrated recovery of nerve structure, myelin organization and axon density to baseline levels, without any residual inflammation, scarring or neuroma formation. No inflammation or scarring was detected in surrounding skin and muscle tissues.

Conclusion

Repeated ice-slurry injections cause temporary, nerve-selective and reversible changes in the peripheral nerve. There was no histologic damage to surrounding skin and muscle tissues. Repeated treatments with injectable ice-slurry for cryoneurolysis appear to be safe and well tolerated. Clinical studies for patients with chronic pain are warranted.

Safety and feasibility of selective tongue fat reduction with injected ice‐slurry

Objectives

There is growing evidence that excess adipose tissue within the head and neck contributes to obstructive sleep apnea (OSA), particularly in obese patients. This subset of the population is often difficult to treat with surgical therapies. We theorized that a novel, transcervical method of injectable cryoablation using ice‐slurry can achieve low temperatures without causing neurovascular damage or airway distress in a swine model.

Methods

Four Yorkshire pigs were injected with ice‐slurry comprised of normal saline and 10% glycerol cooled to −6°C via a transcervical, ultrasound guided approach. Direct laryngoscopy was used to confirm accurate placement of the slurry. Thermocouple placement at the needle‐tip was used to measure temperatures at injection site. Swine were monitored for clinical signs of tongue necrosis and airway edema for 2 months, and then euthanized. Twelve biopsy samples from the base of the tongue were collected for histology. These were assessed for presence of tissue damage, inflammation and collagen formation by a blinded board‐certified pathologist.

Results

Tongue tissue temperature below 10°C was achieved for 13.5 ± 1.1 min. Minimum tissue temperature was −4 ± 0.6°C. There was no clinical or pathological evidence of tongue damage to include damage to the lingual nerve or artery. There was some histologic evidence of new collagen formation in areas of the tongue.

Conclusions

Transcervical ultrasound‐guided ice‐slurry injection is feasible, well‐tolerated at temperatures previously shown to be capable of selectively targeting adipose tissue in the base of the tongue in a preclinical swine model, without causing neurovascular damage or airway distress when properly injected.

Antimicrobial Blue Light for Prevention and Treatment of Highly Invasive Vibrio vulnificus Burn Infection in Mice

Vibrio vulnificus is an invasive marine bacterium that causes a variety of serious infectious diseases. With the increasing multidrug-resistant variants, treatment of V. vulnificus infections is becoming more difficult. In this study, we explored antimicrobial blue light (aBL; 405 nm wavelength) for the treatment of V. vulnificus infections. We first assessed the efficacy of aBL against five strains of V. vulnificus in vitro. Next, we identified and quantified intracellular porphyrins in V. vulnificus to provide mechanistic insights. Additionally, we measured intracellular reactive oxygen species (ROS) production and bacterial membrane permeabilization following aBL exposures. Lastly, we conducted a preclinical study to investigate the efficacy and safety of aBL for the prevention and treatment of burn infections caused by V. vulnificus in mice. We found that aBL effectively killed V. vulnificus in vitro in both planktonic and biofilm states, with up to a 5.17- and 4.57-log₁₀ CFU reduction being achieved, respectively, following an aBL exposure of 216 J/cm². Protoporphyrin IX and coproporphyrins were predominant in all the strains. Additionally, intracellular ROS was significantly increased following aBL exposures (P < 0.01), and there was evidence of aBL-induced permeabilization of the bacterial membrane (P < 0.0001). In the preclinical studies, we found that female mice treated with aBL 30 min after bacterial inoculation showed a survival rate of 81% following 7 days of observation, while only 28% survival was observed in untreated female mice (P < 0.001). At 6 h post-inoculation, an 86% survival was achieved in aBL-treated female mice (P = 0.0002). For male mice, 86 and 63% survival rates were achieved when aBL treatment was given 30 min and 6 h after bacterial inoculation, respectively, compared to 32% survival in the untreated mice (P = 0.0004 and P = 0.04). aBL did not reduce cellular proliferation or induce apoptosis. We found five cytokines were significantly upregulated in the males after aBL treatment, including MCSF (P < 0.001), MCP-5 (P < 0.01), TNF RII (P < 0.01), CXCL1 (P < 0.01), and TIMP-1 (P < 0.05), and one in the females (TIMP-1; P < 0.05), suggesting that aBL may induce certain inflammatory processes. In conclusion, aBL may potentially be applied to prevent and treat V. vulnificus infections.

UV emitting nanoparticles enhance the effect of ionizing radiation in 3D lung cancer spheroids

PURPOSE

Radiation therapy for cancer is limited by damage to surrounding normal tissues, and failure to completely eradicate a tumor. This study investigated a novel radiosensitizer, composed of lutetium phosphate nanoparticles doped with 1% praseodymium and 1.5% neodymium cations (LuPO₄:Pr³⁺,Nd³⁺). During X-ray exposure, the particles emit UVC photons (200-280 nm), resulting in increased tumor cell death, by oxygen-independent UVC-induced damage.

METHODS AND MATERIALS

Specially designed LuPO₄:Pr³⁺,Nd³⁺ nanoscintillator particles were characterized by dynamic light scattering, TEM and emission spectroscopy upon excitation. Cell death was determined by reduction in tumor spheroid growth over a 3-week period using a 3D A549 lung cancer model. Cell cycle was evaluated by flow cytometry and cell death pathways were assessed by Annexin V/PI stain as well as quantify apoptotic bodies.

RESULTS

Lung cancer cells expressed no long-term or non-specific toxicity when incubated with LuPO₄:Pr³⁺,Nd³⁺ nanoscintillators. In contrast, there was significant growth inhibition of cell spheres treated with 2.5 mg/ml LuPO₄:Pr³⁺,Nd³⁺ in combination with ionizing radiation (4 or 8 Gy X-ray), compared to radiation alone. A homogeneous distribution of small NPs throughout the entire sphere resulted in more pronounced lethality and growth inhibition, compared to particle distribution limited to the outer cell layers. Growth inhibition after the combined treatment was caused by necrosis, apoptosis and G₂/M cell cycle arrest.

CONCLUSIONS

Newly designed UVC-emitting nanoscintillators (LuPO₄:Pr³⁺,Nd³⁺) in combination with ionizing radiation cause tumor sphere growth inhibition by inducing cell cycle arrest, apoptosis and necrosis. UVC-emitting nanoparticles offer a promising new strategy for enhancing local tumor response to ionizing radiation treatment.

"Photon recycling" can enhance cutaneous response to lasers: A pilot human study

BACKGROUND

Depending on wavelength and pigmentation, human skin can reflect up to 70% of incident laser light.

AIMS

We tested the hypothesis that returning ("recycling") this diffusely reflected light to the site of laser exposure would increase cutaneous response.

MATERIALS AND METHODS

Thirteen adult volunteers with Fitzpatrick skin types I-IV participated in this IRB-approved study. Matched contralateral test sites on the volar forearms were exposed to a pulsed dye laser operated at 585 nm, 450 microseconds pulse duration in a uniform 5 mm circular exposure spot without skin cooling. On one arm, the laser handpiece was fitted with an aluminized hemispherical mirror with a reflectance of 67%. The minimum fluence causing skin purpura, and the purpura lesion diameter were measured.

RESULTS

The mean purpura threshold fluence with the reflector was 3.1 J/cm² (0.5 SD), and 3.7 J/cm² without the reflector (0.36 SD) (p < 0.001). The mean laser-induced purpura lesion diameter was approximately 5.3 mm with the reflector and 5.0 mm without the reflector.

CONCLUSION

Consistent with a theoretical model and in vitro measurements, this human study confirms that "recycling" reflected laser light can increase skin response. Potentially, the therapeutic response can also be improved with "photon recycling."

Multifunctional patch for use during laser procedures: Optimization and feasibility testing

OBJECTIVE

The objective of this study was to develop a patch that can be placed on the skin during laser hair removal and similar procedures, that serves to reduce the laser-induced plume, provides a ready indicator to the laser surgeon of where pulses have been applied, and cools the skin.

METHODS

A two-layer patch composed of a cooling hydrogel layer and an indicator layer was optimized and tested ex vivo. The hydrogel was composed of gelatin and glycerin. The concentration of each hydrogel component was optimized to determine the minimum gelatin concentration at which the gel can be handled without breakage and the minimum glycerin concentration that allows for storage at -20°C without crystallization. This is the temperature of a conventional freezer; application of the cooling layer to the skin would help prevent epidermal injury. The indicator layer was composed of a plastic transparency sheet with small dots of black ink particles printed onto its surface. Transparency sheets were printed from templates created in Adobe Photoshop in which dots are at a specified density; additionally, Photoshop's opacity function was used to vary the opacity of the dots themselves. Performance was tested using a 755 nm alexandrite laser used clinically for hair removal by measuring light transmission through the patch and observing the sheet's ability to indicate the location of laser exposures. The transmittance of patch components across a broad spectrum was also measured using a microplate reader. Several adhesives, including a two-part epoxy, silicone rubber, and cyanoacrylate, were tested for their ability to adhere to the hydrogel and indicator layers. Assembled patches composed of the hydrogel layer, indicator layer, and adhesive were tested ex vivo for their ability to mitigate the laser hair removal plume by measuring airborne particulate matter during simulated laser hair removal.

RESULTS

A minimum gelatin concentration of 5% was found to enable easy handling of the hydrogel. A mixture composed of 60% water and 40% glycerin by volume consistently allowed storage at -20°C without crystallization. For the indicator layer, ink particle density of 50% and opacity of 5% provided a readily apparent indicator function following laser exposure. Transmission through the sheet measured during alexandrite laser exposures was 90% and was not different than transmission through the sheet alone without ink particles. A cyanoacrylate glue was found to adhere to the hydrogel and indicator layers, while the other adhesives proved inadequate. Measurements using a microplate reader confirmed that the reflection from the transparency sheet itself was the primary contributor to energy loss. In experiments exposing hair clippings to the laser with and without the patch, the patch allowed an increase of 5000 particles/cc relative to baseline particles in the environmental air, while the absence of the patch allowed an increase of 150,000 particles/cc relative to baseline, indicating that the patch decreased particle debris in the plume by 97%.

CONCLUSIONS

A two-layer patch composed of hydrogel and plastic indicator layer with cyanoacrylate adhesive can be stored in a conventional freezer without crystallization, then placed over an area of skin to be treated for laser hair removal. The patch clearly indicates the pattern and sites of laser exposure, while blocking almost all (97%) of particles in the laser-induced plume. Future work will include safety validation and in vivo testing of efficacy, as these were not undertaken in this study.

Hyperbaric phototherapy augments blood carbon monoxide removal

BACKGROUND AND OBJECTIVES

Carbon monoxide (CO) poisoning is responsible for nearly 50,000 emergency department visits and 1200 deaths per year. Compared to oxygen, CO has a 250-fold higher affinity for hemoglobin (Hb), resulting in the displacement of oxygen from Hb and impaired oxygen delivery to tissues. Optimal treatment of CO-poisoned patients involves the administration of hyperbaric 100% oxygen to remove CO from Hb and to restore oxygen delivery. However, hyperbaric chambers are not widely available and this treatment requires transporting a CO-poisoned patient to a specialized center, which can result in delayed treatment. Visible light is known to dissociate CO from carboxyhemoglobin (COHb). In a previous study, we showed that a system composed of six photo-extracorporeal membrane oxygenation (ECMO) devices efficiently removes CO from a large animal with CO poisoning. In this study, we tested the hypothesis that the application of hyperbaric oxygen to the photo-ECMO device would further increase the rate of CO elimination.

STUDY DESIGN/MATERIAL AND METHODS

We developed a hyperbaric photo-ECMO device and assessed the ability of the device to remove CO from CO-poisoned human blood. We combined four devices into a "hyperbaric photo-ECMO system" and compared its ability to remove CO to our previously described photo-ECMO system, which was composed of six devices ventilated with normobaric oxygen.

RESULTS

Under normobaric conditions, an increase in oxygen concentration from 21% to 100% significantly increased CO elimination from CO-poisoned blood after a single pass through the device. Increased oxygen pressure within the photo-ECMO device was associated with higher exiting blood PO₂ levels and increased CO elimination. The system of four hyperbaric photo-ECMO devices removed CO from 1 L of CO-poisoned blood as quickly as the original, normobaric photo-ECMO system composed of six devices.

CONCLUSION

This study demonstrates the feasibility and efficacy of using a hyperbaric photo-ECMO system to increase the rate of CO elimination from CO-poisoned blood. This technology could provide a simple portable emergency device and facilitate immediate treatment of CO-poisoned patients at or near the site of injury.

MagneTEskin-Reconstructing skin by magnetically induced assembly of autologous microtissue cores

Skin wounds are immense medical and socioeconomic burdens, and autologous skin grafting remains the gold standard for wound repair. We recently found that full-thickness micro skin tissue columns (MSTCs) can be harvested with minimal donor site morbidity, and that MSTCs applied to wounds “randomly” (without maintaining their natural epidermal-dermal orientation) can accelerate re-epithelialization. However, despite MSTCs containing all the cellular and extracellular contents of full-thickness skin, normal dermal architecture was not restored by random MSTCs. In this study, we developed a magnetically induced assembly method to produce constructs of densely packed, oriented MSTCs that closely resemble the overall architecture of full-thickness skin to test the hypothesis that maintaining MSTCs’ orientation could further hasten healing and restore a normal dermis. Our method led to faster and more orderly re-epithelialization but unexpectedly did not improve the retention of dermal architecture, which reveals a hitherto unappreciated role for tissue morphology in determining dermal remodeling outcomes.

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-t_1/2 ), 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-t_1/2 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.

Validating Techniques for Measurement of Cutaneous Neurofibromas: Recommendations for Clinical Trials

OBJECTIVE

To assess the reliability and variability of digital calipers, 3D photography, and high-frequency ultrasound (HFUS) for measurement of cutaneous neurofibromas (cNF) in patients with neurofibromatosis type 1 (NF1).

BACKGROUND

cNF affect virtually all patients with NF1 and are a major source of morbidity. Reliable techniques for measuring cNF are needed to develop therapies for these tumors.

METHODS

Adults with NF1 were recruited. For each participant, 6 cNF were assessed independently by 3 different examiners at 5 different time points using digital calipers, 3D photography, and HFUS. The intraclass correlation coefficient (ICC) was used to assess intrarater and interrater reliability of linear and volumetric measurements for each technique, with ICC values >0.90 defined as excellent reliability. The coefficient of variation (CV) was used to estimate the minimal detectable difference (MDD) for each technique.

RESULTS

Fifty-seven cNF across 10 participants were evaluated. The ICC for image acquisition and measurement was >0.97 within and across examiners for HFUS and 3D photography. ICC for digital calipers was 0.62-0.88. CV varied by measurement tool, linear vs volumetric measurement, and tumor size.

CONCLUSIONS

HFUS and 3D photography demonstrate excellent reliability whereas digital calipers have good to excellent reliability in measuring cNF. The MDD for each technique was used to create tables of proposed thresholds for investigators to use as guides for clinical trials focused on cNF size. These criteria should be updated as the performance of these end points is evaluated.

Selective Cryolysis of Melanocytes: Critical Temperature and Exposure Time to Induce Selective Pigmentary Loss in Yucatan Pig Skin

BACKGROUND AND OBJECTIVES

Cryotherapy for melanocytic lesions is often accompanied by collateral damage to the surrounding skin, resulting in skin necrosis and scarring. Adipocytes, like melanocytes, are neural crest-derived cells. Adipocytes have been shown to be more sensitive to cold exposure than their neighboring cells of ectodermal origin, such as epidermal keratinocytes. Such differential sensitivity to cold exposure has led to the development of novel treatment modalities, like cryolipolysis, to selectively target a cell type while sparing neighboring cells.

STUDY DESIGN/MATERIALS AND METHODS

In this study, we investigated the roles of controlled skin freezing, tissue temperature, and exposure time in inducing selective loss of melanocytes and skin depigmentation in swines.

RESULTS

The results of our study demonstrated that contact cooling of the skin surface causes selective loss of epidermal melanocytes when the tissue temperature reaches -7.5°C or cooler with an exposure time of 10 minutes or longer, leading to partial skin depigmentation in swine skin. Longer exposures combined with colder temperature exposure led to more complete depigmentation in the treated skin surface.

CONCLUSION

Cold-sensitivity of melanocytes can be harnessed to selectively remove melanocytes while sparing surrounding keratinocytes. The results from this study demonstrated that improved clinical treatments specifically targeting melanocytic lesions is possible using skin cooling to achieve tissue temperatures capable of inducing selective loss of melanocytes without skin necrosis or scarring. Additional studies are needed to optimize the treatment conditions to prolong the selective removal of melanocytes. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Phototherapy and extracorporeal membrane oxygenation facilitate removal of carbon monoxide in rats

Inhaled carbon monoxide (CO) displaces oxygen from hemoglobin, reducing the capacity of blood to carry oxygen. Current treatments for CO-poisoned patients involve administration of 100% oxygen; however, when CO poisoning is associated with acute lung injury secondary to smoke inhalation, burns, or trauma, breathing 100% oxygen may be ineffective. Visible light dissociates CO from hemoglobin. We hypothesized that the exposure of blood to visible light while passing through a membrane oxygenator would increase the rate of CO elimination in vivo. We developed a membrane oxygenator with optimal characteristics to facilitate exposure of blood to visible light and tested the device in a rat model of CO poisoning, with or without concomitant lung injury. Compared to ventilation with 100% oxygen, the addition of extracorporeal removal of CO with phototherapy (ECCOR-P) doubled the rate of CO elimination in CO-poisoned rats with normal lungs. In CO-poisoned rats with acute lung injury, treatment with ECCOR-P increased the rate of CO removal by threefold compared to ventilation with 100% oxygen alone and was associated with improved survival. Further development and adaptation of this extracorporeal CO photo-removal device for clinical use may provide additional benefits for CO-poisoned patients, especially for those with concurrent acute lung injury.

Construction and validation of UV-C decontamination cabinets for filtering facepiece respirators

We present evidence-based design principles for three different UV-C based decontamination systems for N95 filtering facepiece respirators (FFRs) within the context of the SARS-CoV-2 outbreak of 2019-2020. The approaches used here were created with consideration for the needs of low- and middle-income countries (LMICs) and other under-resourced facilities. As such, a particular emphasis is placed on providing cost-effective solutions that can be implemented in short order using generally available components and subsystems. We discuss three optical designs for decontamination chambers, describe experiments verifying design parameters, validate the efficacy of the decontamination for two commonly used N95 FFRs (3M, #1860 and Gerson #1730), and run mechanical and filtration tests that support FFR reuse for at least five decontamination cycles.

Corneal Stromal Filler Injection as a Novel Approach to Correct Presbyopia-An Ex Vivo Pilot Study

Purpose

To evaluate the ex vivo feasibility of corneal stromal filler injection to create bifocality to correct presbyopia by flattening the central posterior corneal surface and thus increase refractive power.

Methods

Femtosecond laser-assisted corneal stromal pockets of varying diameters close to the posterior corneal curvature were cut into rabbit eyes ex vivo. Subsequently, hyaluronic acid was injected to flatten the central posterior curvature. Refractive parameters were determined using perioperatively acquired three-dimensional optical coherence tomography (OCT) scans. Using micrometer-resolution OCT, corneal endothelial cell morphology and density were evaluated.

Results

Following filler injection into the corneal stromal pockets, a fair volume-dependent increase of central refractive power up to 4 diopters (dpt) was observed. Unremarkable refractive changes of the peripheral posterior (3 mm, 0.20 ± 0.11 dpt; 2 mm, 0.11 ± 0.10 dpt) and the anterior corneal curvature (3 mm, 0.20 ± 0.34 dpt; 2 mm, 0.33 ± 0.31 dpt) occurred. Only negligible changes in astigmatism were observed. Different sizes of optical zones could be established. Furthermore, no alterations of corneal endothelial morphology or endothelial cell density (2831 ± 356 cells/mm² vs. 2734 ± 292 cells/mm²; P = 0.552) due to the adjacent laser treatment were observed.

Conclusions

The ex vivo investigations proved the principle of injecting a filler material into femtosecond laser-created corneal stromal pockets close to the posterior corneal curvature as an efficacious, individually adjustable, and novel approach to correct presbyopia without ablating corneal tissue.

Translational Relevance

Due to the aging population worldwide, presbyopia is an increasing problem; thus, our study may encourage further exploration to extend the treatment spectrum of clinically used femtosecond laser systems to correct presbyopia.

Skin Microcolumns as a Source of Paracrine Signaling Factors

Objective: We recently developed the approach of using “microcolumns” of autologous full-thickness skin tissue for wound repair. The small size of these micro skin tissue columns (MSTCs, ∼0.5 mm in diameter) allows donor sites to heal quickly without scarring. Treatment with MSTCs significantly accelerate wound healing, and suppled various skin cell types and skin structures to replenish the wound volume. This technology is now starting clinical use. In this study, we investigate whether MSTCs may also influence wound healing by releasing soluble signaling factors.

Approach: Freshly harvested MSTCs were incubated in culture medium for 24 h. The conditioned medium was collected and tested for its effects on migration and proliferation of human dermal fibroblasts, and its ability to induce tube formation by human umbilical vein endothelial cells (HUVECs). Proteins released into the conditioned medium were characterized by multiplex enzyme-linked immunosorbent assay (ELISA), and compared with medium conditioned by an equivalent mass of intact full-thickness skin.

Results: MSTC-conditioned medium increased fibroblast migration and proliferation, as well as HUVEC tube formation. MSTCs released many soluble factors known to play prominent roles in wound healing. A subset of proteins showed significantly different release profiles compared with intact full-thickness skin.

Innovation: The technology for harvesting and using MSTCs to augment wound healing was recently developed as an alternative to conventional autologous skin grafting. This study shows that MSTCs could also function as “cytokine factories.”

Conclusion: In addition to supplying autologous cells to repopulate the wound volume, MSTCs can also function as a source of growth factors and cytokines to further enhance wound healing.

Subcutaneous Fat Reduction with Injected Ice Slurry

BACKGROUND

Cryolipolysis is a noninvasive method for removal of subcutaneous fat for body contouring. Conventional cryolipolysis with topical cooling requires extracting heat from subcutaneous fat by conduction across the skin, thus limiting the amount and the location of the fat removed. The authors hypothesized that local injection of a physiological ice slurry directly into target adipose tissue would lead to more efficient and effective cryolipolysis.

METHODS

Injectable slurries containing 20 percent and 40 percent ice content were made using common parenteral agents (normal saline and glycerol), then locally injected into the subcutaneous fat of swine. Ultrasound imaging, photography, histological, and gross tissue responses were monitored before and periodically up to 8 weeks after injection.

RESULTS

Fat loss occurred gradually over several weeks following a single ice slurry injection. There was an obvious and significant 55 ± 6 percent reduction in adipose tissue thickness compared with control sites injected with the same volume of melted slurry (p < 0.001, t test). The amount of fat loss correlated with the total volume of ice injected. There was no scarring or damage to surrounding tissue.

CONCLUSION

Physiological ice slurry injection is a promising new strategy for selective and nonsurgical fat removal.

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.

UVC-Emitting LuPO4:Pr3+ Nanoparticles Decrease Radiation Resistance of Hypoxic Cancer Cells

Radiation-resistant hypoxic tumor areas continue to present a major limitation for successful tumor treatment. To overcome this radiation resistance, an oxygen-independent treatment is proposed using UVC-emitting LuPO₄:Pr³⁺ nanoparticles (NPs) and X rays. The uptake of the NPs as well as their effect on cell proliferation was investigated on A549 lung cancer cells by using inverted time-lapse microscopy and transmission electron microscopy. Furthermore, cytotoxicity of the combined treatment of X rays and LuPO₄:Pr³⁺ NPs was assessed under normoxic and hypoxic conditions using the colony formation assay. Transmission electron microscopy (TEM) images showed no NP uptake after 3 h, whereas after 24 h incubation an uptake of NPs was documented. LuPO₄:Pr³⁺ NPs alone caused a concentration-independent cell growth delay within the first 60 h of incubation. The combined treatment with UVC-emitting NPs and X rays reduced the radiation resistance of hypoxic cells by a factor of two to the level of cells under normoxic condition. LuPO₄:Pr³⁺ NPs cause an early growth delay but no cytotoxicity for the tested concentration. The combination of these NPs with X rays increases cytotoxicity of normoxic and hypoxic cancer cells. Hypoxic cells become sensitized to normoxic cell levels.

A crosslinked polymer skin barrier film for moderate to severe atopic dermatitis: A pilot study in adults

BACKGROUND

Occlusive treatments are a mainstay in atopic dermatitis (AD) management but may not be well tolerated or lack compliance. A comfortable, semiocclusive, artificial skin barrier that is well tolerated, provides protection, and reduces water loss is needed.

OBJECTIVE

To evaluate the potential tolerability and therapeutic benefits of a crosslinked polymer layer (XPL) in adults with AD.

METHODS

A single-center, open-label pilot study was conducted involving 10 subjects with moderate to severe AD. Subjects applied XPL up to twice daily for 30 days on a selected treatment area. Investigator's Global Assessment, clinical signs of eczema, and pruritus were assessed on days 1, 3, 5, 15, and 30. Film durability and patient satisfaction were also evaluated.

RESULTS

Investigator's Global Assessment scores improved from moderate to severe at baseline to clear to almost clear in 8 of 9 patients at day 30. Pruritus improved from trace to severe itching (baseline) to all subjects having trace to no itching at day 30. There was 1 adverse event of mild exudative dermatitis.

LIMITATIONS

The study was limited by small sample size, open-label design, and lack of control.

CONCLUSION

XPL may be an effective adjuvant in AD treatment. A larger study with a control group is warranted.

ONYCHOMYCOSIS: A Review of New and Emerging Topical and Device-based Treatments

Onychomycosis is a challenging nail condition to treat. The gold standard treatment relies on long-term systemic therapy, which carries risks of potential side effects and drug interactions. Topical alternatives exist; however, treatment outcomes remain disappointing. In this article, we review newer topical formulations that are approved by the United States Food and Drug Administration, as well as other topical drugs that are still undergoing clinical trials. Lasers and energy-based devices have also been used for the treatment of onychomycosis; however, standardized parameters and clear treatment endpoints have yet to be specified. Currently, device-based therapies are considered as options for improving the cosmetic appearance of nails. The use of lasers to improve the penetration of topical antifungal treatments as possible combination treatments is also reviewed.

A microscale, full-thickness, human skin on a chip assay simulating neutrophil responses to skin infection and antibiotic treatments

Human skin models are essential for understanding dermatological diseases and testing new treatment strategies. The use of skin biopsies ex vivo is the most accurate model. However, their use is expensive and exposes the donor to pain and scarring. While bioengineered skin samples provide a cheaper alternative, they have limitations due to their simple structure and functionality compared to human skin. Here, we present a skin-on-a-chip device designed to study neutrophil responses to Staphylococcus aureus skin infections. We integrate human skin microcolumns, which have a cross-section that is ∼100 times smaller than traditional skin biopsies, are full-thickness, and are collected using minimally invasive skin sampling techniques. We use human neutrophils directly from one drop of blood, without the need for blood separation. Using the skin-on-a-chip device with skin and blood samples from healthy donors, we show that the neutrophil responses correlate with the bacteria-load in the skin. A pre-incubation step increases the number of migrating neutrophils in response to a low concentration of bacteria. Antibiotic treatment of S. aureus-infected skin samples reduces the number of neutrophils migrating towards the skin. Overall, we validate a skin on a chip model that enables the study of neutrophil migration to the skin in the presence of microbes and following the administration of antibiotics, two situations relevant to clinical cases of human skin and soft tissue infections.

Correction of hyperopia by intrastromal cutting and liquid filler injection

Correction of hyperopia requires an increase of the refractive power by steepening of the corneal surface. Present refractive surgical techniques based on corneal ablation (LASIK) or intrastromal lenticule extraction (SMILE) are problematic due to epithelial regrowth. Recently, it was shown that correction of low hyperopia can be achieved by implanting intracorneal inlays or allogeneic lenticules. We demonstrate a steepening of the anterior corneal surface after injection of a transparent, liquid filler material into a laser-dissected intrastromal pocket. We performed the study on ex-vivo porcine eyes. The increase of the refractive power was evaluated by optical coherence tomography (OCT). For a circular pocket, injection of 1 μl filler material increased the refractive power by +4.5 diopters. An astigmatism correction is possible when ellipsoidal intrastromal pockets are created. Injection of 2 μl filler material into an ellipsoidal pocket increased the refractive power by +10.9  dpt on the short and +5.1  dpt on the long axis. OCT will enable to monitor the refractive change during filler injection and is thus a promising technique for real-time dosimetry.

Laser-assisted delivery enhances topical uptake of the anticancer agent cisplatin

Systemic chemotherapy with the anticancer agent cisplatin is approved for advanced non-melanoma skin cancer (NMSC), but topical treatment is limited by insufficient cutaneous penetration. We studied the impact of ablative fractional laser (AFL) exposure on topical cisplatin’s pharmacokinetics and biodistribution in skin, using microscopic ablation zones reaching the mid- (MAZ-MD; 620 μm depth) and deep dermis (MAZ-DD; 912 μm depth) (λ = 10,600 nm, 196 MAZ/cm²). Assessed in an in vitro Franz cell model after 0.5-, 4-, 24 h topical exposure (n = 8), cisplatin delivery was greatly accelerated by AFL, shown by quantitative- and imaging-based inductively coupled plasma-mass spectrometry (ICP-MS). After 30 minutes, cisplatin concentrations were 91.5, 90.8 and 37.8 μg/cm³ in specific 100-, 500, and 1500 μm skin layers respectively, contrasting to 8.08, 3.12, 0.64 μg/cm³ in non-laser-exposed control skin (p < .001; control vs MAZ-MD). Supported by element bioimaging, the greatest relative increases occurred in the deep skin compartment and at later time points. After 24 h, cisplatin concentrations thus rose to 1829, 1732 and 773 μg/cm³, representing a 25-, 103- and 447-fold enhancement in the 100, 500, and 1500 μm deep skin layers versus corresponding controls (p < .001; MAZ-MD). A significant difference in cutaneous uptake using MAZ-MD and MAZ-DD was not shown at any time point, though deeper laser channels resulted in increased transdermal cisplatin permeation (p ≤ .015). In conclusion, AFL is a rapid, practical and existing skin treatment that may provide greatly enhanced uptake of topical cisplatin for treatment of superficial and deep skin cancer.

UV scintillating particles as radiosensitizer enhance cell killing after X-ray excitation

BACKGROUND AND PURPOSE

Radiation therapy is the gold standard treatment for inoperable malignant tumors. However, due to the heterogeneity of the tumor, some regions are more radio resistant and can lead to metastasis and tumor recurrence. In this study, we propose combining traditional X-ray treatment with UVC-emitting LuPO4:Pr3+ nanoparticles (NPs) to increase the tumor control as well as to reduce tumor recurrence and metastasis. These NPs convert ionizing radiation into UVC-photons (UVC range: 200-280 nm) locally at the tumor site. Unlike X-ray, UVC-photons damage DNA directly via an oxygen-independent mechanism, which could improve treatment of radioresistant tumors such as hypoxic tumors.

MATERIALS AND METHODS

The effect of X-ray generated UVC-photons was tested on human fibroblasts incubated with NPs prior to radiation treatment. The surviving fraction of the cells was assessed by means of colony formation assay. Experiments were performed on normal and UVC sensitive cell lines to demonstrate the presence of UVC photons during treatment. In addition, UV-specific DNA damages were investigated using an immunofluorescence assay to measure cyclopyrimidine dimers (CPDs).

RESULTS

Combined treatment showed an increased cell death of over 50%, compared to radiation alone. This results in a dose equivalent of 4 Gy for the combined treatment with 2 Gy irradiation. The formation of CPDs and the increased effect on UV sensitive cells indicate the presence of UV photons. The generated amount of CPDs is comparable to an UVC exposure of about 15 J × m-2.

CONCLUSION

Combining NPs with ionizing radiation results in a localized dose surge, which could increase tumor control. It could also allow lowering the total applied dose to minimize unwanted side effects to the surrounding normal tissue while maintaining tumor control.

Apparatus for Harvesting Tissue Microcolumns

This manuscript describes the production process for a laboratory apparatus, made from off-the-shelf components, that can be used to collect microcolumns of full-thickness skin tissue. The small size of the microcolumns allows donor sites to heal quickly without causing donor site scarring, while harvesting full-thickness tissue enables the incorporation of all cellular and extracellular components of skin tissue, including those associated with deeper dermal regions and the adnexal skin structures, which have yet to be successfully reproduced using conventional tissue engineering techniques. The microcolumns can be applied directly into skin wounds to augment healing, or they can be used as the autologous cell/tissue source for other tissue engineering approaches. The harvesting needles are made by modifying standard hypodermic needles, and they can be used alone for harvesting small amounts of tissue or coupled with a simple suction-based collection system (also made from commonly available laboratory supplies) for high-volume harvesting to facilitate studies in large animal models.

Considerations for development of therapies for cutaneous neurofibroma

Objective

The only therapies currently available for cutaneous neurofibromas (cNF) are procedural. The goals of the Therapies Development Working Group were to (1) summarize currently available treatment options for cNF, (2) define key considerations for drug discovery and development generally, and specifically for cNF, and (3) outline recommendations for the successful development of medical therapies for cNF.

Methods

The subgroup reviewed published and unpublished data on procedural, drug/device, and medical treatment approaches utilized for cNFs via literature search. The team defined disease- and patient-specific factors to consider for therapies development in a series of consensus meetings.

Results

The team identified 5 approaches entailing procedural and drug/device methods currently under study. There have been 4 clinical studies exploring various interventional therapies, from which outcomes were highly variable. The team identified 4 key factors to prioritize during the development of products for the treatment for cNF: safety, anatomic distribution of cNF, numbers of tumors to be treated, and route of administration.

Conclusions

The number, size, and distribution of cNF is highly variable among patients with NF1 and it is possible that different phenotypes will require different drug development paths. The nonfatal nature of the disease and relatively limited patient numbers suggest that for any product to have a higher likelihood of acceptance, it will have to (1) demonstrate an effect that is clinically meaningful, (2) have a safety profile conducive to long-term dosing, and (3) have a low manufacturing cost.

Fabrication and characterization of UV-emitting nanoparticles as novel radiation sensitizers targeting hypoxic tumor cells

Radiation therapy is one of the primary therapeutic techniques for treating cancer, administered to nearly two-thirds of all cancer patients. Although largely effective in killing cancer cells, radiation therapy, like other forms of cancer treatment, has difficulty dealing with hypoxic regions within solid tumors. The incomplete killing of cancer cells can lead to recurrence and relapse. The research presented here is investigating the enhancement of the efficacy of radiation therapy by using scintillating nanoparticles that emit UV photons. UV photons, with wavelengths between 230 nm and 280 nm, are able to inactivate cells due to their direct interaction with DNA, causing a variety of forms of damage. UV-emitting nanoparticles will enhance the treatment in two ways: first by generating UV photons in the immediate vicinity of cancer cells, leading to direct and oxygen-independent DNA damage, and second by down-converting the applied higher energy X-rays into softer X-rays and particles that are more efficiently absorbed in the targeted tumor region. The end result will be nanoparticles with a higher efficacy in the treatment of hypoxic cells in the tumor, filling an important, unmet clinical need. Our preliminary experiments show an increase in cell death using scintillating LuPO₄:Pr nanoparticles over that achieved by the primary radiation alone. This work describes the fabrication of the nanoparticles, their physical characterization, and the spectroscopic characterization of the UV emission. The work also presents in vitro results that demonstrate an enhanced efficacy of cell killing with x-rays and a low unspecific toxicity of the nanoparticles.

Evaluation and Treatment of Hirsutism in Premenopausal Women: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To update the "Evaluation and Treatment of Hirsutism in Premenopausal Women: An Endocrine Society Clinical Practice Guideline," published by the Endocrine Society in 2008.

PARTICIPANTS

The participants include an Endocrine Society-appointed task force of seven medical experts and a methodologist.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

Group meetings, conference calls, and e-mail communications facilitated consensus development. Endocrine Society committees, members, and cosponsoring organizations reviewed and commented on preliminary drafts of the guidelines.

CONCLUSION

We suggest testing for elevated androgen levels in all women with an abnormal hirsutism score. We suggest against testing for elevated androgen levels in eumenorrheic women with unwanted local hair growth (i.e., in the absence of an abnormal hirsutism score). For most women with patient-important hirsutism despite cosmetic measures (shaving, plucking, waxing), we suggest starting with pharmacological therapy and adding direct hair removal methods (electrolysis, photoepilation) for those who desire additional cosmetic benefit. For women with mild hirsutism and no evidence of an endocrine disorder, we suggest either pharmacological therapy or direct hair removal methods. For pharmacological therapy, we suggest oral combined estrogen-progestin contraceptives for the majority of women, adding an antiandrogen after 6 months if the response is suboptimal. We recommend against antiandrogen monotherapy unless adequate contraception is used. We suggest against using insulin-lowering drugs. For most women who choose hair removal therapy, we suggest laser/photoepilation.

Smartphone confocal microscopy for imaging cellular structures in human skin in vivo

We report development of a low-cost smartphone confocal microscope and its first demonstration of in vivo human skin imaging. The smartphone confocal microscope uses a slit aperture and diffraction grating to conduct two-dimensional confocal imaging without using any beam scanning devices. Lateral and axial resolutions of the smartphone confocal microscope were measured as 2 and 5 µm, respectively. In vivo confocal images of human skin revealed characteristic cellular structures, including spinous and basal keratinocytes and papillary dermis. Results suggest that the smartphone confocal microscope has a potential to examine cellular details in vivo and may help disease diagnosis in resource-poor settings, where conducting standard histopathologic analysis is challenging.

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.

An expanded study of long-pulsed 1064 nm Nd:YAG laser treatment of basal cell carcinoma

BACKGROUND AND OBJECTIVE

Basal cell carcinoma (BCC) is an indolent form of skin cancer that is rarely life threatening, but can cause significant cosmetic and functional morbidity. Surgical treatments often result in disfiguring scars, while topical therapies frequently result in recurrence. The need for a more effective nonsurgical alternative has led to the investigation of laser treatment of BCC. We have previously conducted a pilot study which showed 100% histologic clearance at high fluences. Treatments were well tolerated with no significant adverse events. The objective of this larger study was to confirm preliminary results that the 1064 nm Nd:YAG laser is a safe and effective method for treating non-facial BCC.

DESIGN

This is an IRB-approved, prospective, multi-center study evaluating the safety and efficacy of the 1064 nm Nd:YAG laser for the treatment of BCC on the trunk and extremities. Thirty-three subjects seeking treatment for biopsy-proven BCC that did not meet the criteria for Mohs surgery were recruited. Subjects on current anticoagulation therapy, or with a history of immunosuppression were excluded. Subjects received one treatment with the 1064 nm Nd:YAG laser as follows: 5-6 mm spot, fluence of 125-140 J/cm2 and a pulse duration of 7-10 ms. Standard excision with 5 mm clinical margins was performed at 30 days after laser treatment to evaluate clinical and histologic clearance of BCC. Standardized photographs and adverse assessments were taken at the baseline visit, immediately after laser treatment and on the day of excision.

RESULTS

Thirty-one subjects completed the study. BCC tumors had a 90% (28 of 31 BCC tumors) histologic clearance rate after one treatment with the long-pulsed 1064 nm Nd:YAG laser. Treatments were generally well tolerated without any anesthesia. Immediate side effects included edema and erythema. At 1-month follow-up, some patients had residual crusting. No significant adverse events occurred.

CONCLUSION

The 1064 nm long-pulsed Nd:YAG laser is an alternative for treating non-facial BCC for those that are poor surgical candidates. Lasers Surg. Med. © 2018 Wiley Periodicals, Inc.