NNT mediates redox-dependent pigmentation via a UVB- and MITF-independent mechanism.

Ultraviolet (UV) light and incompletely understood genetic and epigenetic variations determine skin color. Here we describe an UV- and microphthalmia-associated transcription factor (MITF)-independent mechanism of skin pigmentation. Targeting the mitochondrial redox-regulating enzyme nicotinamide nucleotide transhydrogenase (NNT) resulted in cellular redox changes that affect tyrosinase degradation. These changes regulate melanosome maturation and, consequently, eumelanin levels and pigmentation. Topical application of small-molecule inhibitors yielded skin darkening in human skin, and mice with decreased NNT function displayed increased pigmentation. Additionally, genetic modification of NNT in zebrafish alters melanocytic pigmentation. Analysis of four diverse human cohorts revealed significant associations of skin color, tanning, and sun protection use with various single-nucleotide polymorphisms within NNT. NNT levels were independent of UVB irradiation and redox modulation. Individuals with postinflammatory hyperpigmentation or lentigines displayed decreased skin NNT levels, suggesting an NNT-driven, redox-dependent pigmentation mechanism that can be targeted with NNT-modifying topical drugs for medical and cosmetic purposes.

Mechanism of mesenchymal stem cells in spinal cord injury repair through macrophage polarization.

Treatment and rehabilitation of spinal cord injury (SCI) is a major problem in clinical medicine. Modern medicine has achieved minimal progress in improving the functions of injured nerves in patients with SCI, mainly due to the complex pathophysiological changes that present after injury. Inflammatory reactions occurring after SCI are related to various functions of immune cells over time at different injury sites. Macrophages are important mediators of inflammatory reactions and are divided into two different subtypes (M1 and M2), which play important roles at different times after SCI. Mesenchymal stem cells (MSCs) are characterized by multi-differentiation and immunoregulatory potentials, and different treatments can have different effects on macrophage polarization. MSC transplantation has become a promising method for eliminating nerve injury caused by SCI and can help repair injured nerve tissues. Therapeutic effects are related to the induced formation of specific immune microenvironments, caused by influencing macrophage polarization, controlling the consequences of secondary injury after SCI, and assisting with function recovery. Herein, we review the mechanisms whereby MSCs affect macrophage-induced specific immune microenvironments, and discuss potential avenues of investigation for improving SCI treatment.

Using elongated microparticles to enhance tailorable nanoemulsion delivery in excised human skin and volunteers.

This study demonstrates, for the first time, clinical testing of elongated silica microparticles (EMP) combined with tailorable nanoemulsions (TNE) to enhance topical delivery of hydrophobic drug surrogates. Likewise, this is the first report of 6-carboxyfluorescein (a model molecule for topically delivered hydrophobic drugs) AM1 & DAMP4 (novel short peptide surfactants) used in volunteers. The EMP penetrates through the epidermis and stop at the dermal-epidermal junction (DEJ). TNE are unusually stable and useful because the oil core allows high drug loading levels and the surface properties can be easily controlled. At first, we chose alginate as a crosslinking agent between EMP and TNE. We initially incorporated a fluorescent lipophilic dye, DiI, as a hydrophobic drug surrogate into TNE for visualization with microscopy. We compared four different coating approaches to combine EMP and TNE and tested these formulations in freshly excised human skin. The delivery profile characterisation was imaged by dye- free coherent anti-Stoke Raman scattering (CARS) microscopy to detect the core droplet of TNE that was packed with pharmaceutical grade lipid (glycerol) instead of DiI. These data show the EMP penetrating to the DEJ followed by controlled release of the TNE. Freeze-dried formulations with crosslinking resulted in a sustained release profile, whereas a freeze-dried formulation without crosslinking showed an immediate burst-type release profile. Finally, we tested the crosslinked TNE coated EMP formulation in volunteers using multiphoton microscopy (MPM) and fluorescence-lifetime imaging microscopy (FLIM) to document the penetration depth characteristics. These forms of microscopy have limitations in terms of image acquisition speed and imaging area coverage but can detect fluorescent drug delivery through the superficial skin in volunteers. 6-Carboxyfluorescein was selected as the fluorescent drug surrogate for the volunteer study based on the similarity of size, charge and hydrophobicity characteristics to small therapeutic drugs that are difficult to deliver through skin. The imaging data showed a 6-carboxyfluorescein signal deep in volunteer skin supporting the hypothesis that EMP can indeed enhance the delivery of TNE in human skin. There were no adverse events recorded at the time of the study or after the study, supporting the use of 6-carboxyfluorescein as a safe and detectable drug surrogate for topical drug research. In conclusion, dry formulations, with controllable release profiles can be obtained with TNE coated EMP that can effectively enhance hydrophobic payload delivery deep into the human epidermis.

In vivo coherent Raman imaging of the melanomagenesis-associated pigment pheomelanin.

Melanoma is the most deadly form of skin cancer with a yearly global incidence over 232,000 patients. Individuals with fair skin and red hair exhibit the highest risk for developing melanoma, with evidence suggesting the red/blond pigment known as pheomelanin may elevate melanoma risk through both UV radiation-dependent and -independent mechanisms. Although the ability to identify, characterize, and monitor pheomelanin within skin is vital for improving our understanding of the underlying biology of these lesions, no tools exist for real-time, in vivo detection of the pigment. Here we show that the distribution of pheomelanin in cells and tissues can be visually characterized non-destructively and noninvasively in vivo with coherent anti-Stokes Raman scattering (CARS) microscopy, a label-free vibrational imaging technique. We validated our CARS imaging strategy in vitro to in vivo with synthetic pheomelanin, isolated melanocytes, and the Mc1re/e, red-haired mouse model. Nests of pheomelanotic melanocytes were observed in the red-haired animals, but not in the genetically matched Mc1re/e; Tyrc/c ("albino-red-haired") mice. Importantly, samples from human amelanotic melanomas subjected to CARS imaging exhibited strong pheomelanotic signals. This is the first time, to our knowledge, that pheomelanin has been visualized and spatially localized in melanocytes, skin, and human amelanotic melanomas.

Inhibitory effects of Silibinin combined with doxorubicin in hepatocellular carcinoma; an in vivo study.

PURPOSE: Hepatocellular carcinoma (HCC) is the one of the most common cancers and the third leading cause of cancer related mortality in the world. Unacceptable side effect and development of treatment resistance are the major concerns with the conventional chemotherapeutic agents. Combination therapy using phytotherapeutic agents is attracting the attention of investigators in view of the current needs. METHODS: In the present study we have evaluated the synergistic effect of silibinin, a nontoxic phytotherapeutic agent in combination with doxorubicin, in advanced HCC using HEPG2 cells and an orthotopic rat model of HCC. RESULTS: The results showed that silibinin strongly synergized with doxorubicin-induced growth inhibition, G2-M arrest, and apoptosis of HEPG2 cells. Silibinin-doxorubicin combination also inhibited cdc2/p34 kinase activity when histone H1 was used as substrate. The combination regimen also moderately increased the expression of cdc25C-cyclin B1-cdc2/p34 associated upstream kinases (Chk1). Simultaneous treatment with silibinin-doxorubicin combination showed a 41% increase in the apoptotic cell death (p=0.01), which was 3-fold higher than what was observed with silibinin or doxorubicin individually. In the orthotopic rat model treatment with silibinin-doxorubicin reduced tumor growth by close to 30% at nearly twice lower dose of individual drugs in the combination group. CONCLUSIONS: Our study suggests that combination therapy using silibinin-doxorubicin may show a better therapeutic efficacy in patients with HCC. These findings need to be further validated in human clinical trials.

Longitudinal, label-free, quantitative tracking of cell death and viability in a 3D tumor model with OCT.

Three-dimensional in vitro tumor models are highly useful tools for studying tumor growth and treatment response of malignancies such as ovarian cancer. Existing viability and treatment assessment assays, however, face shortcomings when applied to these large, complex, and heterogeneous culture systems. Optical coherence tomography (OCT) is a noninvasive, label-free, optical imaging technique that can visualize live cells and tissues over time with subcellular resolution and millimeters of optical penetration depth. Here, we show that OCT is capable of carrying out high-content, longitudinal assays of 3D culture treatment response. We demonstrate the usage and capability of OCT for the dynamic monitoring of individual and combination therapeutic regimens in vitro, including both chemotherapy drugs and photodynamic therapy (PDT) for ovarian cancer. OCT was validated against the standard LIVE/DEAD Viability/Cytotoxicity Assay in small tumor spheroid cultures, showing excellent correlation with existing standards. Importantly, OCT was shown to be capable of evaluating 3D spheroid treatment response even when traditional viability assays failed. OCT 3D viability imaging revealed synergy between PDT and the standard-of-care chemotherapeutic carboplatin that evolved over time. We believe the efficacy and accuracy of OCT in vitro drug screening will greatly contribute to the field of cancer treatment and therapy evaluation.

ANTIVIRAL ACTIVITY OF DIANTHUS SUPERBUSN L. AGAINST HEPATITIS B VIRUS IN VITRO AND IN VIVO.

BACKGROUND: Hepatitis is a viral infection of hepatitis B virus (HBV). Limitations of drug used in the management of it opens the interest related to alternative medicine. The given study deals with the antiviral activity of Dianthus superbusn L. (DSL) against HBV in vitro & in vivo. MATERIAL AND METHODS: In vitro study liver cell line HepG2.2.15 was used by transinfected it with HBV. Cytotoxicity stduy was performed by using different concentrations of DSL such as 50, 100, 200, 500 & 1000 µg/ml. Anti HBV activity of DSL was estimated by assesing the concentration of HBsAg and HbeAg in cell culture medium by using ELISA. Whereas in vivo study was performed on ducklings and antiviral activity of DSL (100, 200, 400 mg/kg) was confirmed by estimating the serum concentration of HBV DNA and histopathology study of hepatocytes in HBV infected ducklings. RESULT: Result of the study suggested that >500 µg/ml concentration of hydroalcoholic extract of DSL was found tobe cytotoxic. It was also observed that DSL significantly (p<0.05) reduces the concentration of antigenes in cell culture media as per the concentration and days of treatment dependent. Moreover in vivo study confirms the anti viral activity of DSL (200 & 400 mg/kg) as it significantly (p<0.05) decreases the serum concenetration of HBV DNA in HBV infected dukling compared to control group. Histopathology study was also reveals the hepatprotective effect of DSL in HBV infected ducklings. CONCLUSION: The given study concludes the antiviral activity DSL against HBV by in vitro and in vivo models.

Multimodal optical imaging can reveal changes in microcirculation and tissue oxygenation during skin wound healing.

BACKGROUND AND OBJECTIVE: Faster and better wound healing is a longstanding goal. Blood flow, angiogenesis, and tissue oxygenation are important parameters in evaluating the healing process. Optical microangiography (OMAG) allows 3D imaging of tissue vasculature and can provide quantitative blood flow information down to the capillary level of resolution. Dual wavelength laser speckle imaging (DW-LSI) can measure tissue oxygenation status. MATERIALS AND METHODS: Cutaneous wound healing of a mouse ear model using a multimodal imaging system that combines OMAG with DWLSI was studied. RESULTS: A complete microvasculature map of the ear in vivo was obtained. The imaging system revealed both hemodynamic and metabolic changes during acute stage wound healing. Blood flow velocity, blood flow direction, as well as changes in concentration of oxygenated hemoglobin (ΔHbO) and deoxygenated hemoglobin (ΔHb) were measured and quantified. In addition, capillary recruitment and angiogenesis were visualized during the chronic stage of repairing. CONCLUSIONS: The combination of DW-LSI and OMAG imaging technique may be a powerful tool to visualize and understand microvascular, hemodynamic, and metabolic changes during cutaneous wound healing.

Imaging directed photothermolysis through two-photon absorption demonstrated on mouse skin - a potential novel tool for highly targeted skin treatment.

One-photon absorption based traditional laser treatment may not necessarily be selective at the microscopic level, thus could result in un-intended tissue damage. Our objective is to test whether two-photon absorption (TPA) could provide highly targeted tissue alteration of specific region of interest without damaging surrounding tissues. TPA based laser treatments (785 nm, 140 fs pulse width, 90 MHz) were performed on ex vivo mouse skin using different average power levels and irradiation times. Reflectance confocal microscopy (RCM) and combined second-harmonic-generation (SHG) and two-photon fluorescence (TPF) imaging channels were used to image before, during, and after each laser treatment. The skin was fixed, sectioned and H & E stained after each experiment for histological assessment of tissue alterations and for comparison with the non-invasive imaging assessments. Localized destruction of dermal fibers was observed without discernible epidermal damage on both RCM and SHG + TPF images for all the experiments. RCM and SHG + TPF images correlated well with conventional histological examination. This work demonstrated that TPA-based light treatment provides highly localized intradermal tissue alteration. With further studies on optimizing laser treatment parameters, this two-photon absorption photothermolysis method could potentially be applied in clinical dermatology.

Imaging-guided two-photon excitation-emission-matrix measurements of human skin tissues.

There are increased interests on using multiphoton imaging and spectroscopy for skin tissue characterization and diagnosis. However, most studies have been done with just a few excitation wavelengths. Our objective is to perform a systematic study of the two-photon fluorescence (TPF) properties of skin fluorophores, normal skin, and diseased skin tissues. A nonlinear excitation-emission-matrix (EEM) spectroscopy system with multiphoton imaging guidance was constructed. A tunable femtosecond laser was used to vary excitation wavelengths from 730 to 920 nm for EEM data acquisition. EEM measurements were performed on excised fresh normal skin tissues, seborrheic keratosis tissue samples, and skin fluorophores including: NADH, FAD, keratin, melanin, collagen, and elastin. We found that in the stratum corneum and upper epidermis of normal skin, the cells have large sizes and the TPF originates from keratin. In the lower epidermis, cells are smaller and TPF is dominated by NADH contributions. In the dermis, TPF is dominated by elastin components. The depth resolved EEM measurements also demonstrated that keratin structure has intruded into the middle sublayers of the epidermal part of the seborrheic keratosis lesion. These results suggest that the imaging guided TPF EEM spectroscopy provides useful information for the development of multiphoton clinical devices for skin disease diagnosis.

Differentiation of HaCaT cell and melanocyte from their malignant counterparts using micro-Raman spectroscopy guided by confocal imaging.

BACKGROUND: Skin cancer is the most common type of cancer in humans. Current techniques for identifying normal and neoplastic tissues are either destructive or not sensitive and specific enough. Raman spectroscopy and confocal imaging may obviate many limitations of existing methods by providing noninvasive, high-resolution, and real-time morphological and biochemical analysis of living tissues and cells. METHODS: We conducted micro-Raman spectroscopy studies on HaCaT cells, melanocytes (MC) and their malignant counterparts squamous cell carcinoma (SCC) and melanoma (MM) cells, respectively. Reflectance confocal imaging is used as guidance for the spectral measurements. RESULTS: Significant differences were found between the spectra of HaCaT cells and SCC cells, MC cells and MM cells, as well as all normal cells (HaCaT and MC) and all tumor cells (SCC and MM). Approximately 90% sensitivity and specificity was achieved for all the separations that we performed. CONCLUSION: Our results demonstrated the robust capability of confocal Raman spectroscopy in separating different cell lines. The acquired Raman spectra of major types of skin cells and their malignant counterparts will be useful for the interpretation of Raman spectra from in vivo skin. We believe it will eventually help diagnosis of skin cancer and other skin disease in clinical dermatology.

Full range characterization of the Raman spectra of organs in a murine model.

Raman spectroscopy is a minimally-invasive optical technique with great potential for in vivo cancer detection and disease diagnosis. However, there is no systematic study of the Raman spectra from different organs to date. We measured and characterized the Raman spectra eighteen naïve mouse organs in a broad frequency range of 700 to 3100 cm⁻¹. The peaks of generic proteins and lipids appeared in Raman spectra of all organs. Some organs like bone, teeth, brain and lung had unique Raman peaks. The autofluorescence was strong in liver, spleen, heart, and kidney. These results suggest that organ specific Raman probe design and specific data processing strategies are required in order to get the most useful information.

Single-wall carbon nanotubes assisted photothermal cancer therapy: animal study with a murine model of squamous cell carcinoma.

BACKGROUND AND OBJECTIVES: There has been a dramatic increase in photothermal therapy as a minimally invasive treatment modality for cancer treatment due to the development of novel nanomaterials as the light absorption agents. Single-wall carbon nanotubes (SWNTs) with strong optical absorption in the broad visible and near IR offer unique advantages for photothermal cancer therapy. A broad range of wavelengths can be used for the treatment with SWNTs, whereas conventional photothermal therapeutic agent is designed to absorb light only near one selected wavelength. The objective of this study is to validate the hypothesis that intratumoral injected SWNTs can absorb 785 nm near IR laser light and generate significant local hyperthermia to destroy tumors. STUDY DESIGN/MATERIALS AND METHODS: SCCVII tumor in C3H/HeN mice was exposed to 785-nm laser after intratumoral injection of SWNTs with different light and SWNTs dose combinations. The temperatures of the tumor with laser irradiation were monitored. In vivo and ex vivo Raman spectra in different organs were obtained with a rapid Raman system. Tumor responses (tumor volume and mouse survival) were documented daily after treatment up to day 45 to assess the effectiveness of the treatment. RESULTS: The temperature within the tumors increased in a light- and SWNTs-dose dependent manner. Squamous cell carcinomas can be eradicated at a moderate light irradiance and fluence (200 mW/cm² and 120 J/cm²). This light dose is also comparable to those used with photodynamic therapy. Tissue Raman spectroscopy measurements revealed that SWNTs remained localized in the tumor even 3 months after injection but was not found in other organs. CONCLUSIONS: This animal study represents a significant step forward towards the goal of advancing SWNTs based photothermal cancer therapy into clinical applications.

[Study on the pathological uterine tissues with a fiber Raman spectrometry].

The Raman spectrum can reflect the differences in chemical components and molecular structures of tissues and cells, and significant progress has been made in the research on structures, functions and diseases of cells and tissues with Raman spectroscopy. A fiber Raman spectrometer was used to measure the Raman spectra of some uterine malignant, benign, and normal tissues, such as uterine myometrium tissue, uterine myoma tissue, normal endometrium tissue, malignant endometrium tissue and adenomyosis tissue. After having compared the Raman spectrum of pathological tissues with that of the corresponding normal tissues, we observed that the peak referring to Methionine upsilon(C--S) (Met upsilon(C--S)) splits into two peaks in the uterine myoma tissues caused by the vibrations of tryptophan (Trp) and cartotene, which are not present in the normal tissues. There is a peak at 1447 cm(-1) in the endometrium tissues corresponding to CH2--CH3 def, which is one of the characteristic peaks of cancerous tissues. For the adenomyosis tissues, a peak caused by upsilon(C--C) skeletal-alpha helix is obviously weaker than that in normal tissue, and the peak induced by delta(C--O) shifts from 1160 cm(-1) in normal tissues to 1173 cm(-1) in the adenomyosis tissues. Thus, it was demonstrated that the technology of Raman spectroscopy is available for distinguishing different pathological uterine tissues at molecular level. This study is not only helpful on early diagnosis of uterine diseases, but also very crucial for the basic research on uterine diseases. And the Raman spectroscopy technology based on optic-fibers has a potential to evolve into a highly sensitive technology for diagnosis.