TY - JOUR
T1 - Human stratum corneum lipids have a distorted orthorhombic packing at the surface of cohesive failure
AU - Chen, Yen Lane
AU - Wiedmann, Timothy S.
PY - 1996
Y1 - 1996
N2 - The cohesive strength of the stratum corneum is determined by its unique molecular composition and structural architecture. Whereas the structure responsible for corneocyte cohesion has been visualized at the microscopic level, the structure of the intercellular domain has not been characterized at the molecular level. In this report, new insight into the molecular architecture of the stratum corneum has been provided by atomic force microscopy and x-ray photoelectron spectroscopy. The surface layer of human stratum corneum was stripped, yielding the characteristic polygonal corneocytes shown by scanning electron microscopy as well as low resolution atomic force microscopy. With atomic force microscopy, the resolution was increased to allow imaging of the molecular architecture of the stratum corneum. With the high resolution image, a repetitive pattern characteristic of lipids in an ordered state was visualized. The lattice appeared to be orthorhombic where the lattice distances were about 5.5 and 9 Å, and the lattice angle was close to 900. The atomic composition of the superficial layers was 82% carbon, 16.5% oxygen, and 1.4% nitrogen as determined by x-ray photoelectron spectroscopy. The high nitrogen content compared to the calculated stratum corneum lipid composition and measured model lipid composition suggests that proteins were detected. In summary, although proteins are present, the fracture plane of the stratum corneum is largely composed of lipids that appear to have a distorted orthorhombic packing.
AB - The cohesive strength of the stratum corneum is determined by its unique molecular composition and structural architecture. Whereas the structure responsible for corneocyte cohesion has been visualized at the microscopic level, the structure of the intercellular domain has not been characterized at the molecular level. In this report, new insight into the molecular architecture of the stratum corneum has been provided by atomic force microscopy and x-ray photoelectron spectroscopy. The surface layer of human stratum corneum was stripped, yielding the characteristic polygonal corneocytes shown by scanning electron microscopy as well as low resolution atomic force microscopy. With atomic force microscopy, the resolution was increased to allow imaging of the molecular architecture of the stratum corneum. With the high resolution image, a repetitive pattern characteristic of lipids in an ordered state was visualized. The lattice appeared to be orthorhombic where the lattice distances were about 5.5 and 9 Å, and the lattice angle was close to 900. The atomic composition of the superficial layers was 82% carbon, 16.5% oxygen, and 1.4% nitrogen as determined by x-ray photoelectron spectroscopy. The high nitrogen content compared to the calculated stratum corneum lipid composition and measured model lipid composition suggests that proteins were detected. In summary, although proteins are present, the fracture plane of the stratum corneum is largely composed of lipids that appear to have a distorted orthorhombic packing.
KW - Atomic force microscopy
KW - Desquamation
KW - Lipid packing
KW - X-ray photoelectron spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=0030018318&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030018318&partnerID=8YFLogxK
U2 - 10.1111/1523-1747.ep12296521
DO - 10.1111/1523-1747.ep12296521
M3 - Article
C2 - 8752832
AN - SCOPUS:0030018318
SN - 0022-202X
VL - 107
SP - 15
EP - 19
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
IS - 1
ER -