title: Label-free evaluation of angiogenic sprouting in microengineered devices using ultrahigh-resolution optical coherence microscopy.
abstract: Understanding the mechanism of angiogenesis could help to decipher wound healing and embryonic development and to develop better treatment for diseases such as cancer. Microengineered devices were developed to reveal the mechanisms of angiogenesis, but monitoring the angiogenic process nondestructively in these devices is a challenge. In this study, we utilized a label-free imaging technique, ultrahigh-resolution optical coherence microscopy (OCM), to evaluate angiogenic sprouting in a microengineered device. The OCM system was capable of providing ∼1.5-μm axial resolution and ∼2.3-μm transverse resolution. Three-dimensional (3-D) distribution of the sprouting vessels in the microengineered device was imaged over 0.6×0.6×0.5  mm3, and details such as vessel lumens and branching points were clearly visualized. An algorithm based on stretching open active contours was developed for tracking and segmenting the sprouting vessels in 3-D-OCM images. The lengths for the first-, second-, and third-order vessels were measured as 127.8±48.8  μm (n=8), 67.3±25.9  μm (n=9), and 62.5±34.7  μm (n=10), respectively. The outer diameters for the first-, second-, and third-order vessels were 13.2±1.0, 8.0±2.1, and 4.4±0.8  μm, respectively. These results demonstrate OCM as a promising tool for nondestructive and label-free evaluation of angiogenic sprouting in microengineered devices.
authors.affiliation: Lehigh University, Department of Electrical and Computer Engineering, Bethlehem, Pennsylvania 18015bLehigh University, Center for Photonics and Nanoelectronics, Bethlehem, Pennsylvania 18015.
authors.forename: Fengqiang
authors.initials: F
authors.lastname: Li
authors.affiliation: Lehigh University, Department of Computer Science and Engineering, Bethlehem, Pennsylvania 18015.
authors.forename: Ting
authors.initials: T
authors.lastname: Xu
authors.affiliation: University of Pennsylvania, Department of Chemical and Biomolecular Engineering, Philadelphia, Pennsylvania 19104fBoston University, Department of Biomedical Engineering, Boston, Massachusetts 02115gHarvard University, Wyss Institute for Biologically Insp.
authors.forename: Duc-Huy T
authors.initials: DH
authors.lastname: Nguyen
authors.affiliation: Lehigh University, Department of Computer Science and Engineering, Bethlehem, Pennsylvania 18015hLehigh University, Bioengineering Program, Bethlehem, Pennsylvania 18015.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Huang
authors.affiliation: University of Pennsylvania, Department of Chemical and Biomolecular Engineering, Philadelphia, Pennsylvania 19104eUniversity of Pennsylvania, Department of Bioengineering, Philadelphia, Pennsylvania 19104fBoston University, Department of Biomedical Engine.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Chen
authors.affiliation: Lehigh University, Department of Electrical and Computer Engineering, Bethlehem, Pennsylvania 18015bLehigh University, Center for Photonics and Nanoelectronics, Bethlehem, Pennsylvania 18015hLehigh University, Bioengineering Program, Bethlehem, Pennsylvan.
authors.forename: Chao
authors.initials: C
authors.lastname: Zhou
mesh_terms: D000465:Algorithms; D000818:Animals; D003094:Collagen / Q000737:chemistry; D006801:Humans; D021621:Imaging, Three-Dimensional; D008027:Light; D018613:Microscopy, Confocal; D018919:Neovascularization, Physiologic; D041623:Tomography, Optical Coherence / Q000379:methods*
chemical_list: D003094:Collagen