Ageing of facial fat, the role of extracellular collagen from an Electron microscopy point of view

Fine anatomy and ultrastructural composition of
adipose tissue is well known nowadays, On the other
hand better understanding of adipose tissue ageing,
especially in key district as face is a fundamental step
for regenerative medicine and translational research in
field such as plastic surgery. A lot of scientific studies
have been published on the molecular and biochemical
side of this matter, but less work has been performed on
Extra cellular matrix collagen fibrils of face adipose tissue
pads.
This work aims to describe collagen organization,
through different ages, in samples harvested from two
fat areas of the face using Scanning and Transmission
Electron Microscopy techniques and Light microscopy.
During mayor maxillofacial surgery samples have
been harvested from different patients aged 18 to 83
years old specifically Buccal Fat pad and deep malar fat
pad. Fat samples have been fixed in Karnovsky. Later on,
standard SEM, TEM and light Microscopy preparation
was performed.
Collagen fibrils organization in face adipose tissue
can be described mainly by 2 patterns; The first is a
thick mash of small collagen fibrils, known as a pericellular
basket like-structure that we found in all the samples
with low variability. The second pattern is represented
by bundles of intercellular fibrils with same diameter.
Collagen bundles are the structural element giving
adipose tissue the specific mechanical and histological
properties.
Observation of Electron microscopy, both SEM and
TEM, suggested that the quantity of intercellular collagen
fibrils and bundles increase with growing age in
both the fat-pads type analyzed. However, the organization
and the cohesion of the collagen bundles gets lost as
the age of the person increases. Taking into consideration
lower magnification SEM pictures it is clear how the quantity of collagen increases whereas the bond between
adipocytes decreases, therefore also the septa arrangement
blends and gets less defined.