title: Determination of efficacy of a novel alginate dressing in a lethal arterial injury model in swine.
abstract: BACKGROUND
  Alginate is a biocompatible polysaccharide that is commonly used in the pharmaceutical, biomedical, cosmetic, and food industries. Though solid dressings composed of alginate can absorb water and promote wound healing, they are not effective hemostatic materials, particularly against massive hemorrhage. The purpose of this study is to attempt to increase the hemostatic capabilities of alginate by means of hydrophobic modification. Previous studies have illustrated that modifying a different polysaccharide, chitosan, in this way enhances its hemostatic efficacy as well as its adhesion to tissue. Here, it was hypothesized that modifying alginate with hydrophobic groups would demonstrate analogous effects.
  
  
  METHODS
  Fifteen Yorkshire swine were randomized to receive hydrophobically-modified (hm) alginate lyophilized sponges (n=5), unmodified alginate lyophilized sponges (n=5), or standard Kerlix™ gauze dressing (n=5) for hemostatic control. Following a splenectomy, arterial puncture (6mm punch) of the femoral artery was made. Wounds were allowed to freely bleed for 30s, at which time dressings were applied and compressed for 3min in a randomized fashion. Fluid resuscitation was given to preserve the baseline mean arterial pressure. Wounds were monitored for 180min after arterial puncture, and surviving animals were euthanized.
  
  
  RESULTS
  Blood loss for the hm-alginate group was significantly less than the two control groups of (1) alginate and (2) Kerlix™ gauze (p=<0.0001). Furthermore, 80% of hm-alginate sponges were able to sustain hemostasis for the full 180min, whereas 0% of dressings from the control groups were able to achieve initial hemostasis.
  
  
  CONCLUSIONS
  Hm-alginate demonstrates a greatly superior efficacy, relative to unmodified alginate and Kerlix™ gauze dressings, in achieving hemostasis from a lethal femoral artery puncture in swine. This is a similar result as has been previously described when performing hydrophobic modification to chitosan. The current study further suggests that hydrophobic modification of a hydrophilic biopolymer backbone can significantly increase the hemostatic capabilities relative to the native biopolymer.
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Dowling
authors.affiliation: Department of Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
authors.forename: Apurva
authors.initials: A
authors.lastname: Chaturvedi
authors.affiliation: Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, MD 20742, United States.
authors.forename: Ian C
authors.initials: IC
authors.lastname: MacIntire
authors.affiliation: Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, MD 20742, United States.
authors.forename: Vishal
authors.initials: V
authors.lastname: Javvaji
authors.affiliation: Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, MD 20742, United States.
authors.forename: John
authors.initials: J
authors.lastname: Gustin
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States; Department of Chemical & Biomolecular Engineering, University of Maryland, College Park, MD 20742, United States.
authors.forename: Srinivasa R
authors.initials: SR
authors.lastname: Raghavan
authors.affiliation: R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Scalea
authors.affiliation: R Adams Cowley Shock Trauma Center, University of Maryland School of Medicine, Baltimore, MD 21201, United States. Electronic address: 21201mnarayan@umm.edu.
authors.forename: Mayur
authors.initials: M
authors.lastname: Narayan
mesh_terms: D000464:Alginates / Q000494:pharmacology*; D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D005263:Femoral Artery / Q000293:injuries / Q000473:pathology*; D020723:Glucuronic Acid / Q000494:pharmacology; D006470:Hemorrhage / Q000517:prevention & control*; D006487:Hemostasis; D006490:Hemostatics / Q000494:pharmacology*; D006603:Hexuronic Acids / Q000494:pharmacology; D008887:Military Medicine; D013552:Swine; D057772:Vascular System Injuries / Q000473:pathology*; D014945:Wound Healing
chemical_list: D000464:Alginates; D006490:Hemostatics; D006603:Hexuronic Acids; D020723:Glucuronic Acid
keywords: Hemostasis; Hemostatic dressing'; Hm alginate; Modified alginate dressing; Trauma