The photobleaching of 5-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) was investigated during superficial photodynamic therapy (PDT) in normal skin the SKH HR1 hairless mouse. effects light dose and fluence rate on dynamics magnitude corresponding PDT-induced damage were examined. results show that PDT cannot be predicted by total dose. Photobleaching monitored over a wide range initial PpIX fluorescence intensities. is not simple function but dependent concentration...

Photodynamic therapy (PDT) induces cell death through local light activation of a photosensitizer (PS) and has been used to treat head neck cancers. Yet, common PS lack tumor specificity, which leads collateral damage normal tissues. Targeted delivery via antibodies pre-clinically improved selectivity. However, have long half-lives relatively poor tissue penetration, could limit therapeutic efficacy lead photosensitivity. Here, in this feasibility study, we evaluate at the pre-clinical level...

A substantial number of breast cancer patients with an overexpression the human epidermal growth factor receptor 2 (HER2) have residual disease after neoadjuvant therapy or become resistant to trastuzumab. Photodynamic (PDT) using nanobodies targeted HER2 is a promising treatment option for these patients. Here we investigate in vitro and vivo antitumor efficacy HER2-targeted nanobody-photosensitizer (PS) conjugate PDT. Nanobodies targeting were obtained from phage display selections....

Multi diameter single fiber reflectance (MDSFR) spectroscopy is a non-invasive optical technique based on using multiple fibers of different diameters to determine both the reduced scattering coefficient (μs') and parameter γ that related angular distribution scattering, where = (1-g2)/(1-g1) g1 g2 first second moment phase function, respectively. Here we present in vivo MDSFR measurements μs'(λ) γ(λ) their wavelength dependence. performed nineteen mice four tissue types including skin,...

Nonlinear spectral imaging microscopy (NSIM) allows simultaneous morphological and spectroscopic investigation of intercellular events within living animals. In this study we used NSIM for in vivo time-lapse in-depth monitoring protein-bound free reduced nicotinamide adenine dinucleotide (NADH) mouse keratinocytes following total acute ischemia 3.3 h at ~3 min time intervals. The high resolution images discrimination between the two-photon excited fluorescence emission NAD(P)H by applying...

Targeted photodynamic therapy (PDT) has the potential to selectively damage tumor tissue and increase vessel permeability.Here we characterize biodistribution of two EGFR-targeted nanobody-photosensitizer conjugates (NB-PS), monovalent 7D12-PS biparatopic 7D12-9G8-PS.In addition, report on local acute phototoxic effects triggered by illumination these NB-PS which have previously shown lead extensive damage.Methods: Intravital microscopy skin-fold chamber model, containing OSC-19-luc2-cGFP...

Fluorescence photobleaching of protoporphyrin IX (PpIX) during superficial photodynamic therapy (PDT), using 514 nm excitation, was studied in UVB-induced tumor tissue the SKH-HR1 hairless mouse. The effects different irradiance and light fractionation regimes upon kinetics PDT-induced damage were examined. Results show that rate PpIX (i.e., fluorescence intensity vs fluence) PDT both increase with decreasing irradiance. We have also detected formation fluorescent photoproducts PDT, although...

We report on two-photon autofluorescence and second harmonic spectral imaging of live mouse tissues. The use a high sensitivity detector ultraviolet optics allowed us to record razor-sharp deep-tissue images weak short-wavelength generation by skin. Real-color image representation combined with depth-resolved analysis enabled identify tissue structures. results show that linking nonlinear microscopy spectroscopy has the potential provide important information for diagnosis skin

Experimental therapies for Barrett's esophagus, such as 5-aminolevulinic acid (ALA)–based photodynamic therapy (PDT), aim to ablate the premalignant epithelium. However, reproducibility of effects should be improved optimize treatment. Accurate irradiation with light a proper wavelength (633 nm), fluence and rate has shown critical successful ALA-PDT. Here, we have used in situ dosimetry adjust measured within esophagus individual animals monitored protoporphyrin IX (PpIX) fluorescence...

Light fractionation with dark periods of the order hours has been shown to considerably increase efficacy 5-aminolevulinic acid-photodynamic therapy (ALA-PDT). Recent investigations have suggested that this may be due resynthesis protoporphyrin IX (PpIX) during period following first illumination is then utilized in second light fraction. We investigated kinetics PpIX fluorescence and PDT-induced damage PDT normal skin SKH1 HR hairless mouse. A single (514 nm), fluences 5, 10 50 J cm−2 was...

Photodynamic therapy (PDT) using protoporphyrin IX (PpIX) induced by topically applied 5-aminolevulinic acid (ALA) seems a promising alternative for the treatment of superficial non-melanoma skin cancer and actinic keratosis. In this study, kinetics new PpIX fluorescence arising after PDT that had photobleached original were determined. Our purpose was to examine feasibility multiple irradiations, following single topical ALA application, increase efficacy. addition, photobleaching during...

<p>Supplementary Figure 3. Positive control X-ray. (A) Confocal 40x images of T-cell high (left hand side) and low (right KPC clones nucleus (DAPI) yH2AX, 1 hour after X-ray radiation (+) or without (-). (B) Average yH2AX foci per in (magenta) (blue) clones. All the statistics produced here were calculated using two-way ANOVA (analysis variance) followed by Tukey’s method for multiple mean comparison * p < 0.05, ** 0.01, *** 0.005, **** 0.0001.</p>

<div>Abstract<p>Pancreatic ductal adenocarcinoma (PDAC) is one of the most challenging types cancer with little or no response to immune checkpoint inhibitors (ICI). Photodynamic therapy (PDT) has been shown ablate tumors and induce an response. In our study, we investigated effect PDT using photosensitizer Bremachlorin, in its ability reduce tumor burden immunologically sensitize T-cell–high T-cell–low murine PDAC ICIs that blocks PD-1 checkpoint. addition, monitored on survival...

<p>Supplementary Figure 1. Confocal 40x images of control conditions: negative - no Bremachlorin, Mitotracker® Green (left hand side); 100 µM Bremachlorin alone and (middle), MitoTracker® (right side). From top to bottom: Green, composite bright field in T-cell low clones.</p>

<p>Supplementary Figure 6. Representative hematoxylin and eosin (H&E) images of whole tissue slice from T-cell low tumors the different treatment groups, top row (left to right): control, anti-PD-1 alone, PDT alone TS NTS. Bottom TS= treated side, NTS= non-treated side.</p>

<p>Supplementary Figure 7. Representative images at 20x magnification of immunofluorescence analysis CD8+ cells T-cell high 500% tumor tissue PDT and anti-PD-1 treated side (left) non-treated (right) (A). Absolute number quantified in (B). TS= side, NTS= side.</p>

<p>Supplementary Figure 2. Pre-screening the photosensitizer in vitro PDT dose. was performed at four different concentrations of Bremachlorin: 100, 10, 1 and 0.1 µM as well a control (just media) 20mW/cm2 0 (dark control), 5, 20 J/cm2 (biological replicate n=1) T-cell high (top) low (bottom). MTS assay 24 hours after PDT. Dark Ctrl = dark control.</p>

<p>Supplementary Figure 4. Bremachlorin’s ex-vivo bio-distribution of non-homogenized organs. Ex-vivo Bremachlorin from mice with T-cell high (magenta) and low (blue) tumors their organs shown as µg Bremachlorin/g, 6 24 hours after administration (n=4 per group).</p>

<p>Supplementary Figure 5. Representative hematoxylin and eosin (H&E) images of whole tissue slice from T-cell high tumors the different treatment groups, top row (left to right): control, anti-PD-1 alone, PDT alone TS NTS. Bottom TS, NTS Bremachlorin control. TS= treated side, NTS= non-treated side.</p>

Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor, with a median overall survival of 14.6 months. GBM incurable because its invasive growth. These local cells, significantly glioblastoma stem cells (GSCs), when left behind, resist standard treatment, and cause almost all recurrences. However, treatment these infiltrative margins remains significant challenge, as there are currently no options to reach safely. Photodynamic therapy (PDT) shows promise localized option...

Abstract Objective This study aims to determine whether rigid autofluorescence imaging can differentiate cholesteatoma from surrounding tissues reduce residual disease after surgery. Study Design Ex vivo proof‐of‐principle study. Setting Erasmus University Medical Center, Rotterdam, the Netherlands. Methods Autofluorescence signals of cholesteatoma, mucosa, and bone were measured using confocal microscopy confirm distinguishable spectral differences. Subsequently, with specific filter...