Microbial cellulose wound dressing shows potential

An inexpensive wound dressing made from microbial cellulose has demonstrated a notable ability to promote healing in intractable leg ulcers and pressure sores, according to researchers. The dressing received Food and Drug Administration approval in June for the care of all types of wounds, as well as first- and second-degree burns.

In a series of patients suffering a total of 31 leg ulcers, subjects responded well to the cellulose dressing. More than half of the wounds completely healed, and slightly less than half showed marked progress during an eight-week course of treatment. Results in patients with pressure ulcers also were good, but somewhat less impressive.

The dressing is made from high-quality microbial cellulose produced by a process patented by Rensselaer Polytechnic Institute in Troy, NY, and licensed to Xylos, a company located in the Rensselaer business incubator and partially owned by the school.

Xylos hopes to cash in on the moist wound dressing market, which the company expects to reach more than $350 million by the year 2000.

No one is quite sure why the dressings work so well, according to John Brennan, Xylos president. The answer may lie in the physical characteristics of the microbial cellulose, which is highly absorbent. It also is strong, has shape memory and durability, and it is nontoxic and biodegradable, Brennan says.

Most cellulose now used by industry comes from plants, but a microbe (Acetobacter xylinum) produces the world’s best cellulose, according to Gonzalo Serafica, Xylos vice president.

Traditionally, batches of the cellulose have been grown on the surface of plastic trays of a nutrient-rich liquid. Xylos has developed an improved process that produces high-quality cellulose at reduced cost.

New therapy for severe skin disease unveiled

A drug created by pooling blood from multiple donors appears to cure toxic epidermal necrolysis, according to researchers. The disease can be devastating, causing patients to lose large sections of skin. It is fatal in about 30% of cases.

In the Oct. 16 issue of the journal Science, Lars E. French, MD, and his colleagues at Geneva University in Switzerland reported that 10 patients with toxic epidermal necrolysis healed completely after receiving four days’ treatment with intravenous immunoglobulins (IVIG), which occur naturally in blood.

Toxic epidermal necrolysis, a rare condition, is caused most commonly by a reaction to nonsteroidal anti-inflammatory drugs, including aspirin, ibuprofen, and naproxen, and to some drugs used to treat bacterial infections or seizure disorders. IVIG appears to be the first effective treatment against the disease.

French says antibodies in IVIG halt the destruction of surface skin cells, which is a characteristic mechanism of toxic epidermal necrolysis. Symptoms of the disease include wide expanses of red, blistered, denuded skin. Patients often appear as if they’d been scalded.

Among patients in the pilot study of IVIG who received the compound, skin loss stopped within 48 hours after treatment began, according to French. Skin healing was complete in all patients four to 12 days after treatment began, and IVIG caused no significant side effects.

The study authors speculate that IVIG may be a useful therapy for other types of diseases that cause tissue destruction, such as graft-vs.-host disease, which can develop after organ or bone marrow transplants.

Aloe vera can promote wound healing

It’s been used for centuries to soothe burns, and today it’s commonly found as an ingredient in skin care products. But can aloe vera speed the healing of chronic wounds? A Texas A&M University researcher thinks so.

Veterinary pathobiologist Ian Tizard, DVM, PhD, is examining the components that make up the aloe vera plant’s clear jelly interior. He has found that the sugar that constitutes the gel can cut wound healing time by reducing inflammation, slowing the breakdown of growth factors that regulate healing, and stimulating macrophages — the cells that destroy dead or dying tissue and trigger healing.

According to Tizard, aloe vera holds the greatest potential benefit for the elderly, who do not possess the healing power of younger people. He claims that the only other preparations on the market that can accelerate wound healing faster than aloe vera are growth factors. And aloe vera demonstrates an almost total lack of toxicity. "There doesn’t seem to be a downside to aloe vera," he adds.

Tizard’s ongoing research is funded by Carrington Laboratories in Irving, TX.

First Internet wound care database goes on-line

Toronto-based Dumex Corp. has introduced the first on-line searchable wound care database. The WoundHealth Reference Library (WHRL) is accessible through the company’s site on the World Wide Web (

Once inside the WHRL, users can search for articles in six wound care journals. Other databases include chapters and articles from five wound care books, a listing of current wound care books, and the Agency for Health Care Policy and Research pressure ulcer guidelines. Use of the WHRL is free. For a fee, users can purchase full-text articles of abstracts they have found in their searches.

According to Dumex, the database will be updated continually to keep pace with new wound care journal articles and books. The WHRL also will feature free focused discussion groups on wound care hosted by specialists in the field. Discussion group participants will be able to post questions and receive answers from prominent wound care specialists and participate in "best practices" dialogues.

Dumex also offers a free service in which the latest abstracts from the six wound journals are e-mailed to subscribers monthly.

Dumex says the WHRL is the only database that compiles information only about wound care, which will streamline searches by limiting results to wound-related material. The database is available to clinicians, patients, families, and caregivers who have access to the World Wide Web.