Polyhedron

Deformation (meteorology)

Biology

Biomedical engineering

Materials science

Endocrinology

Atomic physics

Electron microscope

Classical mechanics

Hexagonal crystal system

Immunology

Thermodynamics

Contraction (grammar)

Oblate spheroid

Physics

Finite element method

Anatomy

Quadrilateral

Mathematics

Optics

Prolate spheroid

Geometry

Composite material

Crystallography

Compression (physics)

Medicine

Chemistry

Fibrin

Biophysics

Platelet

Scientific Reports

Polyhedral erythrocytes, named polyhedrocytes, are formed in contracted blood clots and thrombi, as a result of compression by activated contractile platelets pulling on fibrin. This deformation was shown to be mechanical in nature and polyhedrocytes were characterized using light and electron microscopy. Through three-dimensional reconstruction, we quantified the geometry of biconcave, intermediate, and polyhedral erythrocytes within contracting blood clots. During compression, erythrocytes became less oblate and more prolate than the biconcave cells and largely corresponded to convex, irregular polyhedra with a total number of faces ranging from 10 to 16. Faces were polygons with 3 to 6 sides. The majority of the faces were quadrilaterals, though not all sides were straight and not all faces were flat. There were no changes in the surface area or volume. These results describe the gradual natural deformation of erythrocytes as a part of compaction into a tightly packed array that is an important but understudied component of mature blood clots and thrombi.

Shape changes of erythrocytes during blood clot contraction and the structure of polyhedrocytes