title: Human albumin solder supplemented with TGF-beta 1 accelerates healing following laser welded wound closure.
abstract: OBJECTIVE
  We examined the possibility that human albumin solder can be used as a vehicle for site specific delivery of growth factors for the purpose of accelerating tissue repair following laser welded wound closure. Certain human recombinant growth factors have been shown to accelerate wound healing in model systems. Pilot in vitro studies have established that several growth factors, including TGF-beta 1, maintain bioactivity following exposure to temperatures achieved during laser tissue welding. Using a temperature controlled laser delivery system (TCL) to precisely maintain welding temperatures, it is now possible to avoid thermal denaturation of exogenous bioactive molecules such as growth factors.
  
  
  METHODS
  HB-EGF, bFGF, and TGF-beta 1 were tested in vitro for maintenance of bioactivity after exposure to 80 degrees C. In vivo experiments using porcine skin determined the efficacy of solders augmented with growth factors. Incisions were repaired using human albumin alone or supplemented with HB-EGF (2 micrograms), bFGF (10 micrograms), or TGF-beta 1 (1 microgram). Wounds were excised at 3, 5, and 7 days post-operatively. Tensile strength, total collagen content, and histology were performed.
  
  
  RESULTS
  At 3 days, tensile strength (TS) of TGF-beta 1 wounds were 36% (P < 0.05) and 20% (n.s.) stronger than laser alone and suture closures, respectively. By 5 days the TS of the TGF-beta 1 group increased by 50% (P < 0.05) and 59% (P < 0.02) over laser alone and suture groups, respectively. At 7 days the TGF-beta 1 group was 50% (P < 0.05) and 79% (P < 0.01) stronger than laser solder alone or suture, respectively. The HB-EGF and bFGF groups were equivalent to the laser solder group at all time points. Total collagen TGF-beta 1 Accelerates Healing Following Laser Welding content at 7 days increased in the TGF-beta 1 group by 7% (n.s.) over the suture group and 21% (P < 0.05) in the laser group.
  
  
  CONCLUSIONS
  Human albumin solder supplemented with TGF-beta 1 increases the early post-operative strength of laser welded wounds. This novel application of laser tissue soldering augmented with a growth factor has the potential to bring about immediate fluid tight seals while providing site specific delivery of biological modifiers. This may lead to an overall improvement in post-operative convalescence, wound infections, and hospital costs.
authors.affiliation: Department of Surgery, Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Poppas
authors.forename: J M
authors.initials: JM
authors.lastname: Massicotte
authors.forename: R B
authors.initials: RB
authors.lastname: Stewart
authors.forename: A B
authors.initials: AB
authors.lastname: Roberts
authors.forename: A
authors.initials: A
authors.lastname: Atala
authors.forename: A B
authors.initials: AB
authors.lastname: Retik
authors.forename: M R
authors.initials: MR
authors.lastname: Freeman
mesh_terms: D000418:Albumins; D000818:Animals; D003094:Collagen / Q000032:analysis; D062109:Dermatologic Surgical Procedures; D006801:Humans; D066298:In Vitro Techniques; D053685:Laser Therapy; D011184:Postoperative Period; D012867:Skin / Q000473:pathology; D012879:Skin Physiological Phenomena; D013537:Sutures; D013552:Swine; D013718:Tensile Strength; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D000418:Albumins; D016212:Transforming Growth Factor beta; D003094:Collagen