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.

A Bayesian network meta-analysis of 14 molecules inhibiting UV daylight-induced pigmentation.

INTRODUCTION: Hyperpigmentation disorders are very frequent, affect the quality of life and may become a psychological burden for afflicted patients. Many anti-pigmenting or depigmenting agents are available with various efficacy and almost no comparative data. 2-mercaptonicotinoyl glycine (2-MNG) was recently proposed as a viable candidate showing safe and effective results on hyperpigmentation control in vitro and in vivo. OBJECTIVES: A Bayesian network meta-analysis (BNMA) was conducted to map and rank the anti-pigmenting and depigmenting efficacy of 2-MNG 0.5% on UV daylight (UVDL)-induced pigmentation together with 13 other reference molecules. A comparison in the kinetics of 2-MNG 0.5% was also performed. METHODOLOGY: Fourteen studies were conducted, for each, on 15-30 women of skin phototype III in Shanghai, China and Paris, France. The products were applied on mini zone, in randomized and blinded protocol, on the back, 5 days a week during 6 weeks, at a dose of 4 mg/cm2 . During the second week, volunteers were exposed under to varying minimum erythemal dose of UVDL during 4 consecutive days-adapted to obtain a similar induction of skin pigmentation regardless of the population. Assessments were performed instrumentally using Chromameter®. Ascorbic acid 7% was used as a positive control for all experiments. A Bayesian network meta-analysis was then established to map and follow the kinetics of 2-MNG 0.5% performance with 13 reference molecules (glutathione 2%, kojic acid 1%, hydroquinone 4%, ascorbyl glucoside 2%, niacinamide 4%, etc.). RESULTS: 2-MNG 0.5% dominated the ranking at all time points with a significant high probability of strong efficacy against UVDL-induced pigmentation. Ascorbic acid 7% ranks second after 4 days of irradiations (D12 ) whereas hydroquinone 4% ranks second 1 month after irradiations (D40 ). In the kinetics, 2-MNG at 0.5% was effective as from the end of irradiations (D12 ) to the study endpoint (D40 ). This suggested an immediate and persistent efficacy across all timepoints evaluated. CONCLUSION: The BNMA revealed a rapid and lasting efficacy of 2-MNG 0.5% on the anti-pigmenting and depigmenting phases of the clinical protocol. 2-MNG 0.5% ranked first, with immediate and lasting effect compared to 13 other references. This study is the first allowing comparison between reference anti-pigmenting and depigmenting agents and will help clinicians for proposing the most effective approach for their patients.

Hydrogen Isotope Separation Using Graphene-Based Membranes in Liquid Water.

Hydrogen isotope separation has been effectively achieved electrochemically by passage of gaseous H2/D2 through graphene/Nafion composite membranes. Nevertheless, deuteron nearly does not exist in the form of gaseous D2 in nature but as liquid water. Thus, it is a more feasible way to separate and enrich deuterium from water. Herein, we have successfully transferred monolayer graphene to a rigid and porous polymer substrate, PITEM (polyimide track-etched membrane), which could avoid the swelling problem of the Nafion substrate as well as keep the integrity of graphene. Meanwhile, defects in the large area of CVD graphene could be successfully repaired by interfacial polymerization resulting in a high separation factor. Moreover, a new model was proposed for the proton transport mechanism through monolayer graphene based on the kinetic isotope effect (KIE). In this model, graphene plays a significant role in the H/D separation process by completely breaking the O-H/O-D bond, which can maximize the KIE, leading to increased H/D separation performance. This work suggests a promising application for using monolayer graphene in the industry and proposes a pronounced understanding of proton transport in graphene.

Does eating with others promote happiness among older adults living alone? A 3-year longitudinal study of the Japan gerontological evaluation study.

OBJECTIVE: Living a happy life is an essential issue for old adults. However, how eating with others contributes to happiness and whether this association is different by living arrangements or not is unknown. The current study examined the relationship between the frequency of eating with others and happiness among older adults according to their living arrangements using 3-year longitudinal data. METHODS: The analyzed sample comprised 18,727 people (10,920 males and 7807 females) with low happiness (0-7 points on score of 0-10 points) from Japan Gerontological Evaluation Study (JAGES) in 2016. Our exposure was the frequency of eating with others: rarely, a few times a year, a few times a month, and a few times a week or more. We performed Modified Poisson Regression to examine the association between the frequency of eating with others and high happiness (8-10 points) in 2019 stratified by living arrangement (living alone/with others). RESULTS: A total of 4352 (23.2%) people showed high happiness in 2019. After adjusting for age, sex, marital status, education, household income, social participation, illnesses under treatment, and depressive symptoms in 2016, the cumulative incidence ratio (CIR) for high happiness in 2019 among people living alone was more significant, that is, 1.28 (95% confidence intervals: 0.88-1.87), 1.50 (1.05-2.14), and 1.82 (1.26-2.63), than 1.28 (1.11-1.48), 1.30 (1.12-1.50), and 1.33 (1.16-1.52) among people living with others for those who ate with others a few times a year, a few times a month, and a few times a week or more compared to those who rarely ate with others, respectively. The interaction between the frequency of eating with others and living arrangements was statistically significant. The trend test showed that higher frequency of eating with others was significantly associated with high happiness. CONCLUSIONS: Eating with others was associated with improved happiness among older adults, with such an association being stronger among people living alone.

[Promoting community gathering places "Kayoinoba" for healthy aging reduce health inequalities among communities: An eight-year ecological study].

Objectives　This study aimed to investigate whether health inequalities among communities would be reduced by intensively enhancing the "Kayoinoba" program in model communities where many high-risk, older adults live.Methods　Kobe City and the Japan Gerontological Evaluation Study created a mail survey for older adults in 78 communities (community ≈ junior high school district) to conduct community diagnosis. Sixteen communities showed poor values along multiple dimensions of risk and required priority measures. From 2014 to 2019, we designated these 16 communities as model communities. Then, municipal officials and researchers cooperated to support the establishment and management of "Kayoinoba." By using four-waves of mail survey data (in 2011, 2013, 2016, and 2019 with n=8,872, 10,572, 10,063, and 5,759, respectively), secular transitions of nine intermediate outcome indicators (three=social participation, two=social network, and four=social support) and five health outcome indicators (physical function, malnutrition, oral function, cognitive function, and depressive symptoms) were compared between model (n=16) and non-model (n=62) communities via multilevel mixed-effects linear regression analysis.Results　In the 2011 and 2013 surveys, model communities showed poor value compared to the non-model communities in 13 of the 14 indicators. A significant interaction between the year and model/non-model communities was confirmed for four intermediate outcome indicators (sports and hobby group participation, number of friends met, and providing emotional support) and three health outcome indicators (oral function, cognitive function, and depressive symptoms). The differences were reduced or eliminated in the 2016 and 2019 surveys. For example, hobby group participation in 2011 was 29.7% vs. 35.0% in model vs. non-model communities; the difference narrowed to 35.2% vs. 36.1% (P=0.008). Similarly, providing emotional support increased from 83.9% vs. 87.0% to 93.3% vs. 93.3% (P=0.007). Depressive symptoms decreased from 31.4% vs. 27.2% to 18.6% vs. 20.3% (P<0.001).Conclusions　Promoting community gathering places "Kayoinoba" for six years in communities where many high-risk older adults live may foster social participation, networking, and support and may help reduce health inequalities among communities.

APETALA 2 transcription factor CBX1 is a regulator of mycorrhizal symbiosis and growth of Lotus japonicus.

KEY MESSAGE: An AP2 family gene CBX1 is involved in mycorrhizal symbiosis and growth of Lotus japonicus. APETALA 2 (AP2) transcriptional regulator is highly conserved in plants. CBX1 from Lotus japonicus is a member of AP2 family. AMF (Arbuscular mycorrhizal fungi) inoculation experiment demonstrated that expression of CBX1 was significantly induced by AMF. Further promoter analysis showed that the - 764 to - 498 bp region of the CBX1 promoter containing CTTC motif is the AMF responsive region. Functional analysis of cbx1 mutant suggested CBX1 is critical for mycorrhizal symbiosis, especially for arbuscule formation. Moreover, under noncolonized condition, overexpression of CBX1 reduced the root length of L. japonicus but increased the size of root system and shoot length, whereas cbx1 mutant reduced the root size and shoot length, but not effect on root length. In addition, cbx1 altered activity of monolignol biosynthetic gene and increased lignin levels. Collectively, these data indicated that CBX1 is a positive regulator of symbiotic activity and plays roles in the growth of L. japonicus.

Novel confocal Raman microscopy method to investigate hydration mechanisms in human skin.

BACKGROUND: Skin hydration is essential for maintaining stratum corneum (SC) flexibility and facilitating maturation events. Moisturizers contain multiple ingredients to maintain and improve skin hydration although a complete understanding of hydration mechanisms is lacking. The ability to differentiate the source of the hydration (water from the environment or deeper skin regions) upon application of product will aid in designing more efficacious formulations. MATERIALS AND METHODS: Novel confocal Raman microscopy (CRM) experiments allow us to investigate mechanisms and levels of hydration in the SC. Using deuterium oxide (D2 O) as a probe permits the differentiation of endogenous water (H2 O) from exogenous D2 O. Following topical application of D2 O, we first compare in vivo skin depth profiles with those obtained using ex vivo skin. Additional ex vivo experiments are conducted to quantify the kinetics of D2 O diffusion in the epidermis by introducing D2 O under the dermis. RESULTS: Relative D2 O depth profiles from in vivo and ex vivo measurements compare well considering procedural and instrumental differences. Additional in vivo experiments where D2 O was applied following topical glycerin application increased the longevity of D2 O in the SC. Reproducible rates of D2 O diffusion as a function of depth have been established for experiments where D2 O is introduced under ex vivo skin. CONCLUSION: Unique information regarding hydration mechanisms are obtained from CRM experiments using D2 O as a probe. The source and relative rates of hydration can be delineated using ex vivo skin with D2 O underneath. One can envision comparing these depth-dependent rates in the presence and absence of topically applied hydrating agents to obtain mechanistic information.

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.

Real-time visualization of melanin granules in normal human skin using combined multiphoton and reflectance confocal microscopy.

BACKGROUND: Recent advances in biomedical optics have enabled dermal and epidermal components to be visualized at subcellular resolution and assessed noninvasively. Multiphoton microscopy (MPM) and reflectance confocal microscopy (RCM) are noninvasive imaging modalities that have demonstrated promising results in imaging skin micromorphology, and which provide complementary information regarding skin components. This study assesses whether combined MPM/RCM can visualize intracellular and extracellular melanin granules in the epidermis and dermis of normal human skin. METHODS: We perform MPM and RCM imaging of in vivo and ex vivo skin in the infrared domain. The inherent three-dimensional optical sectioning capability of MPM/RCM is used to image high-contrast granular features across skin depths ranging from 50 to 90 µm. The optical images thus obtained were correlated with conventional histologic examination including melanin-specific staining of ex vivo specimens. RESULTS: MPM revealed highly fluorescent granular structures below the dermal-epidermal junction (DEJ) region. Histochemical staining also demonstrated melanin-containing granules that correlate well in size and location with the granular fluorescent structures observed in MPM. Furthermore, the MPM fluorescence excitation wavelength and RCM reflectance of cell culture-derived melanin were equivalent to those of the granules. CONCLUSION: This study suggests that MPM can noninvasively visualize and quantify subepidermal melanin in situ.

[Dynamic change of four triterpenic acids contents in different organs of loquat (Eriobotrya japonica) and phenology].

The loquat is widely cultivated in China, its succulent fruits, leaves and flower are used as a traditional medicine for the treatment of many diseases. The study is aimed to analyse the content of the four triterpene compounds ( ursolic acid, corosolic acid, maslinic acid, oleanolic acid) in different organs, and investigate the dynamic changes in different phenological period. The triterpenic acids content in the samples was measured by HPLC based on the plant phenological observations. The results showed that order of four triterpenic acids content in different organs from high to low was defoliation (23.2 mg x g(-1)) > mature leaves (21.7 mg x g(-1)) > young leaves (17.5 mg x g(-1)) > fruits (7.36 mg x g(-1)) > flowers (6.40 mg x g(-1)). The triterpenic acids were not detected in the seeds. The total amount of the four triterpenic acids in the loquat leaves collected in the different phenological stages of sprout, flower bud, blossom and fruit varied between 17.8 and 26.2 mg x g(-1) (defoliation), 16.5 and 23.5 mg x g(-1) (mature leaves), 14.7 and 21.5 mg x g(-1) (young leaves), respectively. The content increased progressively with the leaf development, maturation and aging. There was a higher level of the dry material and triterpenic acids accumulation in the mature leaves during fruit enlargement. This paper attempts to present the case for medicinal plants of a broad geographical distribution to study on the secondary metabolites and harvesting time.

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.

Efficacy and safety of a facial serum and a mask containing salicylic acid and lipohydroxy acid in acne management: A randomized controlled trial.

BACKGROUND: Inflammatory and non-inflammatory acne lesions constitute a significant clinical challenge in acne subjects. AIM: To evaluate the efficacy and safety of a facial serum and a mask containing salicylic acid and lipohydroxy acid for improving skin conditions. METHODS: This randomized controlled trial included adults with comedones, post-inflammatory erythema (PIE) and/or hyperpigmentation (PIH) in Shanghai, China in July 2021. Participants were randomly assigned 1:1 to receive the study Serum + Mask or serum alone for 8 weeks. Acne severity, comedones, papules, pustules, PIE, PIH, skin pores, skin tone evenness, sebum secretion, skin hydration, and trans-epidermal water loss were evaluated at T0d, T1d, T7d, T14d, T28d, and T56d. RESULTS: Eighty-three participants were included, including 41 and 42 in the Serum + Mask and Serum groups, respectively. Acne severity, density of skin pores, skin tone evenness, PIH foci on face, PIE foci on nose, intensity of PIE and PIH, closed comedones on face, open comedones on nose, sebum secretion, and skin hydration were significantly improved from baseline after 8 weeks of treatment in both groups (all p < 0.05). Addition of the mask improved the number of closed comedones (-6.56 ± 0.39 vs. -5.19 ± 0.44, p = 0.022) and acne severity (-0.39 ± 0.08 vs. -0.12 ± 0.09, p = 0.026) substantially more than using the serum alone. No adverse reaction was reported in either group. CONCLUSIONS: The study serum improved skin conditions by regulating skin barrier function and achieving a balance of skin hydration and sebum secretion, removing comedones and improving PIE and PIH. Addition of the mask accelerated the effects without compromising safety.

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.

Heart rate estimation from facial videos with motion interference using T-SNE-based signal separation.

Remote photoplethysmography (RPPG) can detect heart rate from facial videos in a non-contact way. However, head movement often affects its performance in the real world. In this paper, a novel anti-motion interference method named T-SNE-based signal separation (TSS) is proposed to solve this problem. TSS first decomposes the observed color traces into pulse-related vectors and noise vectors using the T-SNE algorithm. Then, it selects the vector with the most significant spectral peak as the pulse signal for heart rate measurement. The proposed method is tested on a self-collected dataset (17 males and 8 females) and two public datasets (UBFC-RPPG and VIPL-HR). Experimental results show that the proposed method outperforms state-of-the-art methods, especially on the videos containing head movements, improving the Pearson correlation coefficient by 5% compared with the best contrasting method. To summarize, this work significantly strengthens the motion robustness of RPPG, which makes a substantial contribution to the development of video-based heart rate detection.

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.

In vivo video rate multiphoton microscopy imaging of human skin.

We present a multiphoton microscopy instrument specially designed for in vivo dermatological use that is capable of imaging human skin at 27 frames per second with 256 pixels × 256 pixels resolution without the use of exogenous contrast agents. Imaging at fast frame rates is critical to reducing image blurring due to patient motion and to providing practically short clinical measurement times. Second harmonic generation and two-photon fluorescence images and videos acquired at optimized wavelengths are presented showing cellular and tissue structures from the skin surface down to the reticular dermis.

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.

A Predictive Self-Organizing Multicellular Computational Model of Infant Skin Permeability to Topically Applied Substances.

Computational models of skin permeability are typically based on assumptions of fixed geometry and homogeneity of the whole epidermis or of epidermal strata and are often limited to adult skin. Infant skin differs quantitatively from that of the adult in its structure and its functional properties, including its barrier function to permeation. To address this problem, we developed a self-organizing multicellular epidermis model of barrier formation with realistic cell morphology. By modulating the parameters relating to cell turnover reflecting those in adult or infant epidermis, we were able to generate accordingly two distinct models. Emerging properties of these models reflect the corresponding experimentally measured values of epidermal and stratum corneum thickness. Diffusion of an externally applied substance (e.g., caffeine) was simulated by a molecular exchange between the model agents, defined by the individual cells and their surrounding extracellular space. By adjusting the surface concentration and the intercellular exchange rate, the model can recapitulate experimental permeability data after topical exposure. By applying these parameters to an infant model, we were able to predict the caffeine concentration profile in infant skin, closely matching experimental results. This work paves the way for a better understanding of skin physiology and function during the first years of life.

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.

Spectroscopic characterization and microscopic imaging of extracted and in situ cutaneous collagen and elastic tissue components under two-photon excitation.

BACKGROUND/PURPOSES: Understanding the two-photon excitation spectral characteristics and microscopic morphology of cutaneous collagen and elastic tissue components is important for applying multiphoton microscopy (MPM) in basic skin biology research and for clinical diagnosis. METHODS: We developed a system for two-photon excitation spectral measurements at various excitation wavelengths. The microscopic morphology was studied using a commercial multiphoton microscope. RESULTS: We obtained two-photon excitation fluorescence (TPEF) excitation-emission matrices (EEM), for the first time, of purified collagen and elastin samples, as well as in situ collagen and elastic fibers within excised human dermis. The EEM of the dermis was found to be similar to that of elastin. The excitation spectra for second harmonic generation (SHG) from purified collagen and excised dermis were also studied and were found to have similar spectral shapes. CONCLUSION: This study, using the EEM spectroscopic approach, confirmed a previous imaging study inference that in the dermis, TPEF predominantly originates from elastic fibers, while SHG originates solely from collagen fibers. The EEM data and SHG excitation spectra obtained in this study can be used to guide the selection of excitation wavelengths for MPM applications in basic skin biology research and for clinical diagnosis.