Special Issue: Selected papers from the Topical Problems of Biophotonics conference (2016)

The ensuing seven papers represent the sampling of the science presented at the Topical Problems in Biophotonics (TPB) conference that took place aboard a cruise ship on the river Volga and its tributaries in July 2015. This bi-annual gathering of active researchers and clinicians in the field of biomedical optics has, over the last decade, become globally renowned for its high-quality science, ample discussion opportunities, informal atmosphere, active participation of experienced and novice researchers alike, beautiful background scenery of the Russian “heartland”, and establishment of both scientific and personal connections and collaborations. It was the fifth conference organized by scientific and educational institutions of Nizhny Novgorod (Institute of Applied Physics RAS, Nizhny Novgorod State Medical Academy, and Nizhny Novgorod State University). We are grateful to the Journal of Biophotonics for providing the opportunity to showcase this special conference. The breadth and depth of TPB's science was reflected in its three sub-conferences (Optical BioImaging, Nanobiophotonics, and Novel Laser Bio-Applications) and two workshops (Clinical Biophotonics and Tumour & Stem Cell Biology). These seven representative Journal of Biophotonics papers were selected from various tracks of the conference, have undergone the journal's rigorous peer-review process, and span the range from volumetric optical imaging to novel contrast agents to advanced microscopies. Specifically, Liu et al. 1 report on a mouse study using optical coherence tomography (OCT) to enable high diagnostic accuracy for glomerulonephritis based on structural and elastic tissue parameters. Wang et al. 2 employed Doppler OCT for four-dimensional live monitoring of hemodynamics in a mammalian embryonic heart with quantification of blood flow velocity. Yashchenok et al. 3 describe the fabrication methodology of polyelectrolyte microcapsules characterized by very high absorption in NIR, with promising potential as contrast agents for both photoacoustic imaging and for therapy (theranostics). Another class of photonic contrast agents are nanodiamonds that are amenable to bio-functionalization; their nanotoxicity in a zebrafich embryo model is examined by Lin et al. 4. Razali et al. 5 report on imaging photoluminescent nanoruby probes with wide-field time-gated photoluminescence microscopy, demonstrating significant increase in imaging contrast. Kalinina et al. 6 present an approach to mapping cell metabolic parameters and pO2 by combined use of FLIM and PLIM, demonstrating an attractive imaging platform for ex vivo monitoring of tumor oxygen status (a key determinant for proper treatment strategy selection). In vivo monitoring of oxygen saturation in the brain by NIR spectroscopy provides unique opportunities for non-invasive brain disorder diagnostics and monitoring; thus, Clancy et al. 7 present MRI-based numerical simulation of NIR spectroscopy towards improving the accuracy of quantitative mapping of oxygen saturation in brain. As seen from this brief overview of the selected titles, research in biophotonics presented at TPB-15 is interesting and exciting indeed. On behalf of the TPB's organizing committee and its enthusiastic attendees, we wish you pleasant “light” reading of these papers and look forward to your active participation in TPB-17!