WOUND-HEALING - EFFECTS OF CLOSING TENSION, ZYPLAST(TM), AND PLATELET-DERIVED GROWTH-FACTOR

Previous studies have shown that beginning 5 to 7 days from wounding, the tensile strength of wounds closed under tension in rats is signifi cantly higher than the tensile strength of wounds closed without tensi on. This study evaluated the effects of increased closing tension, zyp last implant (ZI), and human recombinant platelet-derived growth facto r (PDGF) on the tensile strength of wounds, Six groups of 12 rats each were divided into two main subsets: wounds were closed without tensio n in three groups and with high tension of approximately 100 g in the three other groups, In both no-tension and high-tension groups, one su bgroup received no intervention (controls), one subgroup received ZI ( zyplast controls), and one subgroup received ZI-PDGF (ZI used as a car rier for PDGF), Healing was evaluated by tensile strength determinatio ns at 5 days. For the controls, wounds closed under tension showed a t rend toward higher tensile strength, but statistical significance was not reached, Compared with controls, tensile strength was 45% lower in the wounds with ZI and closure with tension (P = .0063) and 38% lower in the wounds with ZI and closure without tension (P = .007). Treatme nt with ZI-PDGF resulted in 69% higher tensile strengths (P = .049) as compared with ZI controls for wounds closed with tension, This study demonstrated the beneficial effect of PDGF in accelerating healing in wounds closed under tension. Although ZI was able to deliver PDGF to t he wound, the use of this substance as a carrier is questioned since i t was detrimental to healing.