Direct Observation of Calcium Oxalate Monohydrate Precipitation at Phospholipid Monolayers with Brewster Angle Microscopy

2003 ◽  
Vol 774 ◽  
Author(s):  
Isa O. Benítez ◽  
Rénal Backov ◽  
Saeed R. Khan ◽  
Daniel R. Talham
Keyword(s):  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Brewster Angle ◽  
Brewster Angle Microscopy ◽  
Phase Boundaries ◽  
Phospholipid Monolayers ◽  
Bright Spots ◽  
Two Phases ◽  
Scanning Electron

AbstractThe precipitation of calcium oxalate monohydrate (COM) at phospholipid monolayers has been observed in-situ by Brewster angle microscopy (BAM). A monolayer of 1,2-dipalmitoylsn-glycero-3-phosphocholine (DPPC) compressed to a LC state over a calcium oxalate subphase shows the growth of COM as very bright spots. The identity of COM was confirmed in a transferred film by scanning electron microscopy. BAM can also be used to determine where COM precipitates when the monolayer has two phases at equilibrium. Monolayers of DPPC and 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (DPPG) crystallize COM at phase boundaries. In addition, phase separated binary phospholipid mixtures of DPPC and 1,2-dimiristoyl-sn-glycero-3-phosphocholine (DMPC) have been prepared and monitored by BAM. The crystal growth in this case is confined to domains of DPPC due to its ability to form a liquid condensed phase.

Calcium Oxalate Monohydrate Precipitation at Phospholipid Monolayer Phase Boundaries

2004 ◽  
Vol 823 ◽  
Author(s):  
Isa O. Benítez ◽  
Daniel R. Talham
Keyword(s):  
Calcium Oxalate ◽  
Phase Boundary ◽  
Langmuir Monolayers ◽  
Calcium Oxalate Monohydrate ◽  
Brewster Angle ◽  
Crystal Formation ◽  
Brewster Angle Microscopy ◽  
Phase Boundaries ◽  
Phospholipid Monolayer

AbstractThe precipitation of calcium oxalate monohydrate (COM) was observed at biphasic phospholipid Langmuir monolayers with the aid of Brewster angle microscopy. COM appears preferentially at phase boundaries of a monolayer of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) in a state of liquid expanded/liquid condensed coexistance. However, when the phase boundary is created by two different phospholipids that are phase segregated, such as DPPC and 1,2-dimiristoyl-sn-glycero-3-phosphocholine (DMPC), crystal formation occurs away from the interface. It is suggested that COM growth at phase boundaries is preferred only when there is molecular exchange between the phases.

Epitaxial Relationships in Urolithiasis: The Brushite—Whewellite System

1977 ◽  
Vol 52 (2) ◽  
pp. 143-148 ◽  
Author(s):  
J. L. Meyer ◽  
J. H. Bergert ◽  
L. H. Smith
Keyword(s):  
Crystal Growth ◽  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Supersaturated Solution ◽  
Scanning Electron Micrographs ◽  
Phosphate Dihydrate ◽  
Acid Environment ◽  
Time Required ◽  
Insight Into ◽  
Scanning Electron

1. Whewellite (calcium oxalate monohydrate) crystals were found to induce epitaxially the heterogeneous nucleation of brushite (calcium monohydrogen phosphate dihydrate) from its metastable supersaturated solution in approximately one-quarter of the time required for spontaneous precipitation in the absence of added nucleating agents. Scanning electron-microscope observation of the crystalline phase showed brushite crystals originating from the whewellite seed crystals. 2. Crystal growth, upon nucleation, proceeded rapidly, and the metastable solutions quickly approached saturation. 3. Brushite crystals also induced the precipitation of calcium oxalate crystals in about one-quarter of the time required for spontaneous precipitation; however, the rate of crystal growth was considerably slower. In support of the chemical data, scanning electron micrographs showed few crystals of calcium oxalate nucleated on the surface of the brushite seed. 4. The results provide some insight into the cause of stones containing calcium oxalate or calcium phosphate (or both), which form in the normally acid environment of human urine.

Oriented growth of calcium oxalate monohydrate crystals beneath phospholipid monolayers

1998 ◽  
Vol 1380 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Shelli R Letellier ◽  
Michael J Lochhead ◽  
Allison A Campbell ◽  
Viola Vogel
Keyword(s):  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Oriented Growth ◽  
Phospholipid Monolayers

Probing Crystallization of Calcium Oxalate Monohydrate and the Role of Macromolecule Additives with in Situ Atomic Force Microscopy

Langmuir ◽  
2004 ◽  
Vol 20 (20) ◽  
pp. 8587-8596 ◽  
Author(s):  
Taesung Jung ◽  
Xiaoxia Sheng ◽  
Chang Kyun Choi ◽  
Woo-Sik Kim ◽  
Jeffrey A. Wesson ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Force Microscopy ◽  
Atomic Force
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