Nanouric acid or nanocalcium phosphate as central nidus to induce calcium oxalate stone formation: a high-resolution transmission electron microscopy study on urinary nanocrystallites

Int J Nanomedicine. 2014 Sep 16:9:4399-409. doi: 10.2147/IJN.S66000. eCollection 2014.

Abstract

Purpose: This study aimed to accurately analyze the relationship between calcium oxalate (CaOx) stone formation and the components of urinary nanocrystallites.

Method: High-resolution transmission electron microscopy (HRTEM), selected area electron diffraction, fast Fourier transformation of HRTEM, and energy dispersive X-ray spectroscopy were performed to analyze the components of these nanocrystallites.

Results: The main components of CaOx stones are calcium oxalate monohydrate and a small amount of dehydrate, while those of urinary nanocrystallites are calcium oxalate monohydrate, uric acid, and calcium phosphate. The mechanism of formation of CaOx stones was discussed based on the components of urinary nanocrystallites.

Conclusion: The formation of CaOx stones is closely related both to the properties of urinary nanocrystallites and to the urinary components. The combination of HRTEM, fast Fourier transformation, selected area electron diffraction, and energy dispersive X-ray spectroscopy could be accurately performed to analyze the components of single urinary nanocrystallites. This result provides evidence for nanouric acid and/or nanocalcium phosphate crystallites as the central nidus to induce CaOx stone formation.

Keywords: EDS; HRTEM; calcium oxalate stones; heterogeneous nucleation; nanocrystallites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium Oxalate / chemistry
  • Calcium Oxalate / urine
  • Calcium Phosphates / chemistry*
  • Calcium Phosphates / urine*
  • Humans
  • Microscopy, Electron, Transmission
  • Nanoparticles / chemistry*
  • Nanoparticles / ultrastructure*
  • Uric Acid / chemistry
  • Uric Acid / urine*
  • Urinary Calculi / chemistry*
  • Urinary Calculi / urine*

Substances

  • Calcium Phosphates
  • Calcium Oxalate
  • Uric Acid
  • calcium phosphate