LifeCell Corp. and BioSurface Technology on Monday reportedpromising data from early wound treatment trials.
LifeCell (NASDAQ:LIFC) said its dermal tissue product fortreating full-thickness wounds becomes vascularized andsupports the growth of host fibroblasts.
And BioSurface Technology, a private company based inCambridge, Mass., said that its wound healing dressing, whichconsists of cultured human cells, appears to promote healing inpartial thickness burns.
Both companies presented their preliminary clinical trial dataat the Fifth international Symposium on Wound Healing andWound Management, sponsored by the International BurnFoundation and held in New Orleans over the weekend.
The preliminary results on LifeCell's product come fromobservations of four patients from three different burn centers,Jane Lee Hicks, LifeCell's vice president of corporatedevelopment told BioWorld.
Each patient received a small piece of the AlloDerm tissue grafton part of the surface of the open wound. The entire full-thickness burn wound bed was then covered with a split-skingraft from another part of the patient's body. The cliniciansperformed a biopsy on one of these graft sites at day 12.
Histologically, "what we are seeing indicates thatvascularization and cell proliferation will occur, at least by day12," Hicks said. And, she added, in all four patients thesuperficial appearance of the wound -- such as adherence ofthe graft to the wound bed and pink color -- is encouraging.
Although it's "too early to measure an immune response," Hicksadded, there was no visible rejection of the tissue graft.
"It's the first clinical indication that AlloDerm may be acceptedby burn patients as a replacement for the foundational skinlayer," said Paul Frison, president and chief executive officer ofThe Woodlands, Texas-based LifeCell. Eventually, about 60patients at six burn centers will be enrolled in the AlloDermclinical trials, Hicks said.
The trouble with conventional skin grafts is that they don'ttake; the patient often rejects them within weeks afterapplication, if not sooner. LifeCell's proprietary tissueengineering approach removes from living human donor skinthe epidermal keratinocytes and fibroblast cells that causerejection, leaving intact the underlying dermis.
David Stone, an analyst with Cowen & Co. in Boston, explainedthat the keratinocytes are the most prone to stimulatingrejection. "Fibroblasts will be rejected ultimately as well, butnot as quickly," he said.
"Skin is one of the most difficult organs to transplant acrosshistocompatibility barriers, " said Stone.
A full-thickness wound larger than a 50-cent piece will notheal by itself, said Stone, but partial-thickness wounds will re-epithelialize on their own. And adding cultured fibroblasts andkeratinocytes to the wound bed, for instance, may provide abiologically active dressing to accelerate the healing process --a more efficient biobandage, Stone said.
BioSurface Technology's Acticel wound healing dressing couldbe just such a band-aid for deep partial thickness burns. TimSurgenor, BioSurface's vice president, claimed that this is thefirst controlled trial to show that lab-grown tissue is effectivein wound-healing. The results suggested that Acticel canpromote healing in these wounds as rapidly as skin grafts. Deeppartial-thickness burns will not heal spontaneously withinthree weeks.
The product, which consists of cultured human fibroblastsderived from foreskins, was tested against two others: a split-thickness skin graft and an inert plastic dressing. "Acticelhealed 43 percent faster than the inert dressing, and wasequivalent to the split-thickness graft," said Surgenor. Acticeldoesn't take permanently, he said. Both treatments healed thewounds in about eight days.
"Acticel works by stimulating the healing of cells that arealready there," said Surgenor. "These cells are known toproduce over 25 different growth factors and maintenanceproteins."
-- Jennifer Van Brunt Senior Editor
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