title: Frequent Application of the New Gelatin-Collagen Nonwoven Accelerates Wound Healing.
abstract: OBJECTIVE
  Mortality after chronic wounds is high. Thus, proper and effective therapy is of critical importance. Adult mammalian skin cannot regenerate spontaneously. It heals under scar formation in a process of repair. In general, wound closure is achieved through a combination of contraction, scar formation, and regeneration. To enhance wound healing, research groups are continuously inventing and evaluating novel skin replacement products. A single application of a new gelatin-collagen nonwoven accelerates wound closure of full-thickness skin defects. Therefore, the authors' objective was to evaluate the effect of a higher application frequency of the nonwoven on wound closure in a minipig model.
  
  
  METHODS
  Four full-thickness skin defects were created surgically on the dorsum of 12 Göttingen minipigs. Next, 3 wounds were treated randomly with a novel gelatin-collagen nonwoven in different thicknesses, while the fourth wound was left untreated and served as the control wound. Moreover, 6 minipigs achieved multiple applications of the wound dressing. During the experimental period of 21 days, a close-up photographic documentation was performed. Finally, the areas of the initial wounds were excised and examined histologically.
  
  
  RESULTS
  More frequent application of the nonwoven achieved accelerated wound healing and better epidermis quality compared with a single application. Mean time until wound closure of all wounds treated with a multiple application of the nonwoven was 11.0 (± 1.2) days, compared with a single application of the nonwoven with 12.4 (± 1.26) days and control wounds with 13.5 (± 1.19) days. Furthermore, the epidermal thickness of all wounds treated with multiple applications of the nonwoven was increased by 10.67 μm (31.89 ± 8.86 μm, P = .0007) compared with a single application of the nonwoven and by 6.53 μm (27.75 ± 7.24 μm, P = .0435) compared with the control group.
  
  
  CONCLUSIONS
  Multiple applications of the gelatin-collagen nonwoven may be an appropriate treatment for chronic wounds leading to a fast wound closure through a combination of contraction and re-epithelialization.
authors.affiliation: Jennifer L. Schiefer, MD, is a Resident, Clinic for Plastic and Hand Surgery, Burn Care Center, University of Witten/Herdecke, Cologne Merheim Medical Center, Cologne, Germany. Rebekka Rath, MD, was a student at the time of this writing; Manuel Held, MD, is a Resident; Wiebke Petersen, MD, is a Resident; Jan-Ole Werner, MD, was a student at the time of this writing; Hans-Eberhard Schaller, MD, is Director; all at the Clinic of Plastic, Reconstructive, Hand and Burn Surgery, BG-Trauma Center, Eberhard-Karls University, Tuebingen, Germany. Afshin Rahmanian-Schwarz, MD, is Director of the Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, Helios Clinic, Wuppertal, Germany. The authors disclose that this research project was supported in part by a grant from Freudenberg New Technologies SE & Co KG Group and Biopharm GmbH, Weinheim, Germany. The authors acknowledge that study animals were treated according to the German Law on the Protection of Animals, and the study was performed with permission from the Baden-Württemberg Animal Welfare Committee. Submitted April 20, 2014; accepted in revised form September 12, 2014.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Schiefer
authors.forename: Rebekka
authors.initials: R
authors.lastname: Rath
authors.forename: Manuel
authors.initials: M
authors.lastname: Held
authors.forename: Wiebke
authors.initials: W
authors.lastname: Petersen
authors.forename: Jan-Ole
authors.initials: JO
authors.lastname: Werner
authors.forename: Hans-Eberhard
authors.initials: HE
authors.lastname: Schaller
authors.forename: Afshin
authors.initials: A
authors.lastname: Rahmanian-Schwarz
mesh_terms: D000818:Animals; D001458:Bandages; D003094:Collagen; D004195:Disease Models, Animal; D012883:Skin Ulcer / Q000473:pathology / Q000628:therapy*; D013552:Swine; D054457:Tissue Scaffolds; D014945:Wound Healing
chemical_list: D003094:Collagen