Infectious pneumonia is a major cause of morbidity/mortality, mainly due to the increasing rate of microorganisms resistant to antibiotics. Photodynamic Inactivation (PDI) is emerging as a promising treatment option, which effects are based on oxidative stress, targeting several biomolecules and probably preventing potential resistant strains. In previous studies, the in vitro inactivation of Streptococcus pneumoniae using indocyanine green (ICG) and infrared (IR) light source (780 nm) was successful, and achieving satisfactory reduction of colony-forming units (CFU/mL). In the present study, a proof-of-principle protocol was designed to treat lung infections by PDI using extracorporeal irradiation with a 780 nm laser device and nebulized ICG as photosensitizer. Balb/c mice were infected with S. pneumoniae and PDI was performed two days after infection using 800 μM of nebulized ICG and extracorporeal irradiation. Our results indicate that IR-extracorporeal PDI using nebulized ICG may be considered a potential pneumonia treatment, and pulmonary decontamination with PDI may be used as a single therapy or as an adjuvant for antibiotics.
While Optical Coherence Microscopy (OCM), Multiphoton Microscopy (MPM), and narrowband imaging are powerful imaging techniques that can be used to detect cancer, each imaging technique has limitations when used by itself. Combining them into an endoscope to work in synergy can help achieve high sensitivity and specificity for diagnosis at the point of care. Such complex endoscopes have an elevated risk of failure, and performing proper modelling ensures functionality and minimizes risk. We present full 2D and 3D models of a multimodality optical micro-endoscope to provide real-time detection of carcinomas, called a salpingoscope. The models evaluate the endoscope illumination and light collection capabilities of various modalities. The design features two optical paths with different numerical apertures (NA) through a single lens system with a scanning optical fiber. The dual path is achieved using dichroic coatings embedded in a triplet. A high NA optical path is designed to perform OCM and MPM while a low NA optical path is designed for the visible spectrum to navigate the endoscope to areas of interest and narrowband imaging. Different tests such as the reflectance profile of homogeneous epithelial tissue were performed to adjust the models properly. Light collection models for the different modalities were created and tested for efficiency. While it is challenging to evaluate the efficiency of multimodality endoscopes, the models ensure that the system is design for the expected light collection levels to provide detectable signal to work for the intended imaging.
Endomicroscopy techniques such as confocal, multi-photon, and wide-field imaging have all been demonstrated using coherent fiber-optic imaging bundles. While the narrow diameter and flexibility of fiber bundles is clinically advantageous, the number of resolvable points in an image is conventionally limited to the number of individual fibers within the bundle. We are introducing concepts from the compressed sensing (CS) field to fiber bundle based endomicroscopy, to allow images to be recovered with more resolvable points than fibers in the bundle. The distal face of the fiber bundle is treated as a low-resolution sensor with circular pixels (fibers) arranged in a hexagonal lattice. A spatial light modulator is located conjugate to the object and distal face, applying multiple high resolution masks to the intermediate image prior to propagation through the bundle. We acquire images of the proximal end of the bundle for each (known) mask pattern and then apply CS inversion algorithms to recover a single high-resolution image. We first developed a theoretical forward model describing image formation through the mask and fiber bundle. We then imaged objects through a rigid fiber bundle and demonstrate that our CS endomicroscopy architecture can recover intra-fiber details while filling inter-fiber regions with interpolation. Finally, we examine the relationship between reconstruction quality and the ratio of the number of mask elements to the number of fiber cores, finding that images could be generated with approximately 28,900 resolvable points for a 1,000 fiber region in our platform.
Usually, tissue images at cellular level need biopsies to be done. Considering this, diagnostic devices, such as microendoscopes, have been developed with the purpose of do not be invasive. This study goal is the development of a dual-channel microendoscope, using two fluorescent labels: proflavine and protoporphyrin IX (PpIX), both approved by Food and Drug Administration. This system, with the potential to perform a microscopic diagnosis and to monitor a photodynamic therapy (PDT) session, uses a halogen lamp and an image fiber bundle to perform subcellular image. Proflavine fluorescence indicates the nuclei of the cell, which is the reference for PpIX localization on image tissue. Preliminary results indicate the efficacy of this optical technique to detect abnormal tissues and to improve the PDT dosimetry. This was the first time, up to our knowledge, that PpIX fluorescence was microscopically observed in vivo, in real time, combined to other fluorescent marker (Proflavine), which allowed to simultaneously observe the spatial localization of the PpIX in the mucosal tissue. We believe this system is very promising tool to monitor PDT in mucosa as it happens. Further experiments have to be performed in order to validate the system for PDT monitoring.
Colorectal adenoma (CA) is a disease caused by various factors (such as genetic factors or environmental exposures). The appearance of colon polyp (CP) within colorectal might indicate the hint of CA development. Ball-lens hollow fiber Raman probe (BHRP) may has a high capability for detection of CA in living experimental animal and have already tested to rat’s CP in this study, which was designed to collaborate between BHRP with mini-endoscopy to observe the biochemical alteration within normal colon tissue and rat’s colon polyps in real time. BHRP and mini-endoscopy can distinguish the differences in their finger print spectra and make pictures the control and CP in the real time. At the first step, the real situation of normal colon and Rat’s CP were washed by saline and observed with mini-endoscopy. BHRP was introduced to Dextran sodium sulphate (DSS)-induced Rat's CP to detect some of biochemical alteration. The main purpose of this study was to introduce mini-endoscopy to guide the BHRP for diagnosing of CP in real time and to compare it with spectra of normal colon (control group) in living rat. As the result, BHRP can provide the differences in band of control and CP group, which can inform that the biochemical of normal and CP has changed. As a major parameter to distinct normal and CP tissue were phosphatidylinositol, phosphodiester group, lipid, and collagen. Mini endoscopy and BHRP is very sensitive devices for diagnosing of CP in real time.