Nonlinear optical endomicroscopy for label-free functional histology in vivo

Abstract

This manuscript reports on the first two-photon, label-free, metabolic imaging of biological tissues in vivo at histological resolution on an extremely compact, fiber-optic endomicroscopy platform. This system provides new opportunities for performing non-invasive and functional histological imaging of internal organs in vivo, in situ and in real time. As a routine clinical procedure, traditional histology has made significant impacts on medicine. However, the procedure is invasive and time consuming, suffers random sampling errors, and cannot provide in vivo functional information. The technology reported here features an extremely compact and flexible fiber-optic probe ~2 mm in diameter, enabling direct access to internal organs. Unprecedented two-photon imaging quality comparable to a large bench-top laser scanning microscope was achieved through technological innovations in double-clad fiber optics and miniature objective lenses (among many others). In addition to real-time label-free visualization of biological tissues in situ with subcellular histological detail, we demonstrated for the first time in vivo two-photon endomicroscopic metabolic imaging on a functioning mouse kidney model. Such breakthroughs in nonlinear endoscopic imaging capability present numerous promising opportunities for paradigm-shifting applications in both clinical diagnosis and basic research.

Miniscope GRIN Lens System for Calcium Imaging of Neuronal Activity from Deep Brain Structures in Behaving Animals

“…Combined with the GRadient INdex (GRIN) lens which relays optical images from one end to the other, in vivo imaging has extended into deep brain regions more recently (Barretto, Messerschmidt, & Schnitzer, 2009). Moreover, with the development of miniature microscopes with epifluorescent (Ghosh et al, 2011) or two-photon light source (Helmchen, Fee, Tank, & Denk, 2001; Liang, Hall, Messerschmidt, Li, & Li, 2017; Sawinski et al, 2009; Zong et al, 2017), the accompanying behavior tests have expanded from head-fixed animals to freely-moving animals.…”

Intravital imaging of adriamycin-induced renal pathology using two-photon microscopy and optical coherence tomography

“…Two-photon microscopy (TPM) is a rapidly emerging technology for high-resolution°u orescence molecular imaging and intravital studies. 14,[19][20][21][22][23][24][25][26][27][28][29][30] TPM has been used for kidney function studies to image blood°ow, glomerular ltration and permeability, tubular°ow dynamics and tubular re-absorption. [14][15][16][31][32][33] Optical coherence tomography (OCT) is another established biophotonic imaging technology, which has been developed for subsurface imaging of tissues with high resolution (< 10 m) and 1-2 mm penetration depth.…”

A biopsy‐needle compatible varifocal multiphoton rigid probe for depth‐resolved optical biopsy

“…The fiber launch, the grating pair and the detection unit were mounted on an 18*12 inch breadboard with all-fiber-optic connections for easy integration with a portable femtosecond laser in the future. For kidney and small intestinal imaging, we adopted the same imaging protocol as previously published [35]. For kidney imaging, a small dorsal incision was created on an isoflurane sedated mouse, through which the left kidney was exteriorized and lifted for imaging.…”