Here - EWMA 2013

ETRS GUEST SESSION: WOUND HEALING AND WOUND RESEARCH
ETRS Guest Session: Wound Healing and Wound Research
95
The role of cellular senescence in tissue homeostasis and
in cell replacement therapies
Dimitris Kletas 1
1 Laboratory of Cell Proliferation & Ageing, Institute of Biosciences and Applications,
National Centre for Scientific Research “Demokritos” (Athens, Greece).
96
ETRS Guest Session: Wound Healing and Wound Research
Influence of topical negative pressure therapy on formation of
new granulation tissue
Gerrolt Jukema 1 , Michael S.Timmers 2
1 Department of Surgery, Division of Trauma Surgery, University Hospital Zürich (Zürich,
Switzerland);
2 Departrment of Surgery, Red Cross Hospital (Beverwik, the Netherlands)
Background: Infektion of wounds and implants cause prolonge hospitalisation of
patients and can lead to multiple surgical procedure. And in the case there is an ongoing
infektion or posttraumatic osteomyelitis, even invalidating amputations can’t be
prevented in all cases. Negative pressure wound therapy can influence local blood flow
circulation in the wound bed, thus improving wound healing. To investigate the influence
of negative pressure setting on local blood flow, a swine study was perforemd.
Materials and Methods: In a swine study with full thinknes wounds (10x15 cm) Laser
Doppler measurements of the local blood flow in the woundbed were performed for the
polyurthane und polyvinyl alkoholfoam. Each swine became four surigical wounds and
was randomised for the position of both types of foam (front or back position). Each
swine became both foams simultaneously during the experiments. The range of negative
pressure was between 25 and 500 mm Hg, and was during the experiement gradually
raised. For both foams a statistical significant rise of the Laser Doppler blood flow in the
wounds was measured in the range from 25 to 200/300 mm Hg (P < 0.05). During the
experiements with follow up of 1 week, a negative pressure setting related observation
with stimulation of granulation tissue in wounds was observed.
Conclusions: After the randomsized Laser Doppler blood flow study of the skin in
humans (1), now in a open wound model in swine, a negative pressure setting
dependent influence in stimulating the local blood flow and formation of granulating
tissue in wounds could be demonstrated.
References: 1. Timmers MS, Le Cessie S, Banwell P, Jukema GN: The effects of
varying degrees of pressure delivered by negative pressure wound therapy on skin/
tissue perfusion. Ann Plast Surg 2005:Dec;55(6)665-671
Normal cells can enter a state of permanent arrest after serial subculturing (“replicative
senescence”) or after exposure to different types of genotoxic stresses (“stress-induced
premature senescence”). Both types of senescence are characterized by a common
underlying mechanism, i.e. the activation of a DNA damage response leading to the
triggering of the p53-p21-pRb axis and subsequently to growth arrest. Beyond their
inability for proliferation, senescent cells express a catabolic/pro-inflammatory
phenotype, thus affecting tissue homeostasis locally and most probably play a role in
various age-related diseases. One of the most promising approaches for tissue repair
and regeneration is the use of mesenchymal stem cells due to their potency to
differentiate towards various cell lineages. However, the number of stem cells from
various sources is limited, thus making their serial subculture before their use
imperative. Interestingly, mesenchymal stem cells have also a limited lifespan in vitro.
Senescent stem cells also express a pro-inflammatory phenotype and, in addition, they
have a diminished ability for differentiation towards many cell lineages. Interestingly,
several genotoxic stresses, such as anticancer treatments, accelerate the senescence
process and the alterations in their capacity to differentiate, thus intervening with their
ability for tissue regeneration.
EWMA 2013
COPENHAGEN
15-17 May · 2013
Danish Wound
Healing Society
67