title: Combining micro-computed tomography with histology to analyze biomedical implants for peripheral nerve repair.
abstract: BACKGROUND
  Biomedical implants used in tissue engineering repairs, such as scaffolds to repair peripheral nerves, can be too large to examine completely with histological analyses. Micro-computed tomography (micro-CT) with contrast agents allows ex vivo visualization of entire biomaterial implants and their interactions with tissues, but contrast agents can interfere with histological analyses of the tissues or cause shrinkage or loss of antigenicity.
  
  
  METHODS
  Soft tissue, ex vivo micro-CT imaging using Lugol's iodine was compatible with histology after using a rapid (48 h) method of removing iodine.
  
  
  RESULTS
  Adult normal and repaired rat sciatic nerves were infiltrated ex vivo with iodine, imaged with micro-CT and then the iodine was removed by incubating tissues in sodium thiosulfate. Subsequent paraffin sections of normal nerve tissues showed no differences in staining with hematoxylin and eosin or immunostaining with multiple antibodies. Iodine treatment and removal did not alter axonal diameter, nuclear size or relative area covered by immunostained axons (p>0.05). Combining imaging modalities allowed comparisons of macroscopic and microscopic features of nerve tissues regenerating through simple nerve conduits or nerve conduits containing a titanium wire for guidance.
  
  
  METHODS
  Quantification showed that treatment with iodine and sodium thiosulfate did not result in tissue shrinkage or loss of antigenicity.
  
  
  CONCLUSIONS
  Because this combination of treatments is rapid and does not alter tissue morphology, this expands the ex vivo methods available to examine the success of biomaterial implants used for tissue engineering repairs.
authors: Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, United States.
authors: Tracy M
authors: TM
authors: Hopkins
authors: Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, United States.
authors: Alexander M
authors: AM
authors: Heilman
authors: Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, United States.
authors: James A
authors: JA
authors: Liggett
authors: Vontz Core Imaging Lab (VCIL), University of Cincinnati College of Medicine, Cincinnati, United States.
authors: Kathleen
authors: K
authors: LaSance
authors: Division of Pediatric Orthopaedics, Cincinnati Children's Hospital Medical Center, Cincinnati, United States.
authors: Kevin J
authors: KJ
authors: Little
authors: Division of Facial Plastic & Reconstructive Surgery, Program Director for the Facial Paralysis Clinic, Department of Otolaryngology-Head and Neck Surgery, University of Cincinnati College of Medicine, Cincinnati, United States.
authors: David B
authors: DB
authors: Hom
authors: Department of Bioengineering, University of Pittsburgh, Pittsburgh, United States.
authors: Danielle M
authors: DM
authors: Minteer
authors: Departments of Plastic Surgery and Bioengineering, University of Pittsburgh, Pittsburgh, United States; Plastic Surgery Research Laboratory, Faculty, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, United States.
authors: Kacey G
authors: KG
authors: Marra
authors: Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Cincinnati, United States. Electronic address: Sarah.pixley@uc.edu.
authors: Sarah K
authors: SK
authors: Pixley
mesh_terms: D000818:Animals; D001369:Axons / Q000000981:diagnostic imaging / Q000473:pathology; D002208:Caproates; D048429:Cell Size; D003287:Contrast Media; D005260:Female; D007150:Immunohistochemistry / Q000379:methods*; D007454:Iodides; D007783:Lactones; D008297:Male; D008856:Microscopy, Fluorescence / Q000379:methods; D064847:Multimodal Imaging / Q000379:methods; D009416:Nerve Regeneration; D016612:Paraffin Embedding / Q000379:methods; D010784:Photomicrography; D011917:Rats, Inbred Lew; D012584:Sciatic Nerve / Q000166:cytology / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery; D013885:Thiosulfates; D054457:Tissue Scaffolds; D014025:Titanium; D055114:X-Ray Microtomography / Q000379:methods*
chemical_list: D002208:Caproates; D003287:Contrast Media; D007454:Iodides; D007783:Lactones; D013885:Thiosulfates; C121056:caprolactone; D014025:Titanium; C017717:sodium thiosulfate; C010389:Lugol's solution
keywords: Biomedical implants; Immunostaining; Iodine; Lugol's; Micro-CT; Peripheral nerve regeneration; Sodium thiosulfate; Tissue engineering