title: Polyethylene glycol formulations show different soft tissue remodeling and angiogenesis features.
abstract: BACKGROUND
  Soft tissue regeneration and remodeling is fundamental in periodontal surgery, thus we investigated the angiogenic response elicited in the subcutaneous tissue of rats by a proprietary, polyethylene glycol hydrogel formulation (PEG) alone or conjugated with specific amelogenins (EMD) or nanobioglass particles (NBG).
  
  
  METHODS
  Discs with three different formulations (PEG, PEG-EMD, and PEG-NBG) were inserted into four unconnected subcutaneous pouches, produced on the back of Sprague-Dawley rats (n=56, divided into three groups), and used for blood flow evaluation by Laser Doppler analysis at 1, 2, 4, 8, and 16 weeks or for histological and immunohistochemical analysis at 1, 2, 4, 8, and 16 weeks.
  
  
  RESULTS
  All formulations showed tissue integration, absence of inflammatory reaction (as revealed by myeloperoxidase staining), and increased vascularization (by counting microvascular density following CD31 staining). Laser Doppler analysis revealed a statistically significant increase in blood flow after 1 week for PEG-EMD and after 2 weeks for PEG-NBG. The angiogenic response was significantly increased at 1, 2, and 8 weeks for PEG-EMD, but only at 4 weeks for PEG-NBG.
  
  
  CONCLUSIONS
  The studied biomaterials revealed equal biocompatibility and tissue integration properties. PEG-EMD showed the most pronounced and consistent angiogenic response in the early phases of wound healing, while the PEG-NBG formulation provided a slower and delayed, but relevant, response.
authors.affiliation: 1 Department of Dentistry and Medical and Surgical Experimental Sciences, University of Messina , Messina, Italy .
authors.forename: Giacomo
authors.initials: G
authors.lastname: Oteri
authors.forename: Gabriele
authors.initials: G
authors.lastname: Pizzino
authors.forename: Michele
authors.initials: M
authors.lastname: Pisano
authors.forename: Matteo
authors.initials: M
authors.lastname: Peditto
authors.forename: Francesco
authors.initials: F
authors.lastname: Squadrito
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bitto
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis; D004339:Drug Compounding; D004867:Equipment Design; D019544:Equipment Failure Analysis; D048091:Guided Tissue Regeneration / Q000295:instrumentation* / Q000379:methods; D016557:Guided Tissue Regeneration, Periodontal / Q000295:instrumentation*; D008422:Materials Testing; D018919:Neovascularization, Physiologic / Q000502:physiology*; D011092:Polyethylene Glycols / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D023822:Tissue Engineering / Q000295:instrumentation; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D011092:Polyethylene Glycols