title: [Experimental study of the effect of chitosan on the capsule inside the expanded flap].
abstract: OBJECTIVE
  To investigate the effect of chitosan on the capsule inside the expanded flap.
  
  
  METHODS
  The expanders were implanted in animals with the treatment of chitosan(experimental group, n = 15) or without (control group, n = 15). After taking out the expanders, the flap contraction rate was calculated. The samples were observed through HE, Masson dyeing and CD34 immunohistochemical study. The thickness of capsule inside the expanded flap was measured under microscope. The samples were also studied under electron microscope.
  
  
  RESULTS
  The thickness of capsule was 516.000 +/- 128.491 microm in the experimental group, and 833.000 +/- 227.379 microm in the control group (P < 0.05). The number of microvessels was 8.200 +/- 2.150 per visual in experimental group, and 7.900 +/- 1.729 per visual in control group (P > 0.05). Under the electron microscope, the rough endoplasmic reticulum (RER) in the capsule in experimental group decreased and enlarged with degranulation. The mitochondria emerged or disappeared. The number of ribosome was reduced. In the control group, the RER enlarged without degranulation, the mitochondria was intact. The number of ribosome was not reduced.
  
  
  CONCLUSIONS
  The chitosan can effectively reduce the contraction of expanded flap through collagen secretion of fibroblast, delaying the differentiation from fibroblast to fiber cell, inhibiting thansform from fibroblast to myofibroblast. It has no effect on the microvascular generation and expansion, so the flap blood supply will not be affected with thicker capsule.
authors.affiliation: Health Management Center, Beijing Electric Power Hospital, Beijing 100073, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Qiu
authors.forename: Guo-Hua
authors.initials: GH
authors.lastname: Chu
authors.forename: Wen-Zhe
authors.initials: WZ
authors.lastname: Guo
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.forename: Sheng
authors.initials: S
authors.lastname: Han
mesh_terms: D000818:Animals; D048271:Chitosan / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006085:Graft Survival; D008297:Male; D011817:Rabbits; D016038:Skin Transplantation / Q000379:methods; D013524:Surgical Flaps; D015626:Tissue Expansion
chemical_list: D048271:Chitosan