title: In vivo Quantification of the Effects of Radiation and Presence of Hair Follicle Pores on the Proliferation of Fibroblasts in an Acellular Human Dermis in a Dorsal Skinfold Chamber: Relevance for Tissue Reconstruction following Neoadjuvant Therapy.
abstract: BACKGROUND
  In neoadjuvant therapy, irradiation has a deleterious effect on neoangiogenesis. The aim of this study was to examine the post-implantation effects of neoadjuvant irradiation on the survival and proliferation of autologous cells seeded onto an acellular human dermis (hAD; Epiflex). Additionally, we examined the influence of dermal hair follicle pores on viability and proliferation. We used dorsal skinfold chambers implanted in rats and in-situ microscopy to quantify cell numbers over 9 days.
  
  
  METHODS
  24 rats received a skinfold chamber and were divided into 2 main groups; irradiated and unirradiated. In the irradiated groups 20Gy were applied epicutaneously at the dorsum. Epiflex pieces were cut to size 5x5mm such that each piece had either one or more visible hair follicle pores, or no such visible pores. Fibroblasts were transduced lentiviral with a fluorescent protein for cell tracking. Matrices were seeded statically with 2.5x104 fluorescent fibroblasts and implanted into the chambers. In each of the two main groups, half of the rats received Epiflex with hair follicle pores and half received Epiflex without pores. Scaffolds were examined in-situ at 0, 3, 6 and 9 days after transplantation. Visible cells on the surface were quantified using ImageJ.
  
  
  RESULTS
  In all groups cell numbers were decreased on day 3. A treatment-dependent increase in cell numbers was observed at subsequent time points. Irradiation had an adverse effect on cell survival and proliferation. The number of cells detected in both irradiated and non-irradiated subjects was increased in those subjects that received transplants with hair follicle pores.
  
  
  CONCLUSIONS
  This in-vivo study confirms that radiation negatively affects the survival and proliferation of fibroblasts seeded onto a human dermis transplant. The presence of hair follicle pores in the dermis transplants is shown to have a positive effect on cell survival and proliferation even in irradiated subjects.
authors.affiliation: Division of Surgical Oncology and Thoracic Surgery, Department of Surgery, University Medical Centre Mannheim, University of Heidelberg, Germany.
authors.forename: Mario
authors.initials: M
authors.lastname: Vitacolonna
authors.affiliation: Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Germany.
authors.forename: Djeda
authors.initials: D
authors.lastname: Belharazem
authors.affiliation: Department of Radiation Oncology, University Medical Center Mannheim, University of Heidelberg, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Maier
authors.affiliation: Division of Surgical Oncology and Thoracic Surgery, Department of Surgery, University Medical Centre Mannheim, University of Heidelberg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Hohenberger
authors.affiliation: Division of Surgical Oncology and Thoracic Surgery, Department of Surgery, University Medical Centre Mannheim, University of Heidelberg, Germany.
authors.forename: Eric Dominic
authors.initials: ED
authors.lastname: Roessner
mesh_terms: D062088:Acellular Dermis; D000818:Animals; D049109:Cell Proliferation / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D005347:Fibroblasts / Q000166:cytology* / Q000528:radiation effects / Q000637:transplantation; D005720:Gamma Rays; D018859:Hair Follicle / Q000166:cytology* / Q000528:radiation effects / Q000637:transplantation; D006801:Humans; D008297:Male; D020360:Neoadjuvant Therapy; D009369:Neoplasms / Q000628:therapy; D051381:Rats; D011916:Rats, Inbred F344; D016038:Skin Transplantation; D023822:Tissue Engineering; D014182:Transplantation, Autologous; D014183:Transplantation, Heterologous; D014945:Wound Healing