Prisma wound dressing, sold as Promogran Prisma, is a collagen-based wound treatment designed for chronic and hard-to-heal wounds that produce fluid. It is FDA-cleared for a wide range of wound types, from diabetic foot ulcers and venous leg ulcers to surgical wounds that have reopened after closure. The dressing works by calming the destructive chemical environment inside stalled wounds so healing can restart.
Wound Types It Treats
Prisma is cleared for use on exuding (fluid-producing) wounds under the supervision of a healthcare professional. The full list of indicated wound types is broad:
- Diabetic ulcers, typically on the feet
- Venous ulcers, usually on the lower legs
- Pressure ulcers (bedsores)
- Ulcers from mixed circulation problems
- Full-thickness and partial-thickness wounds
- Skin donor sites and other bleeding surface wounds
- Abrasions and traumatic wounds healing from the inside out
- Surgical wounds that have split open after initial closure
It can also be paired with negative pressure wound therapy (wound vac systems) for a more limited set of these wound types, including partial-thickness burns.
What the Dressing Is Made Of
Prisma is a sterile, freeze-dried sheet composed of three active components: 55% collagen, 44% oxidized regenerated cellulose (ORC), and 1% silver-ORC. The collagen and ORC form a matrix that interacts directly with the wound environment. The silver component provides a low level of antimicrobial protection, delivering about 20 micrograms of silver per square centimeter of dressing.
When placed on a moist wound, the dry matrix absorbs fluid and forms a soft gel that conforms to the wound bed. This gel is what delivers the dressing’s therapeutic effects directly where they’re needed.
How It Helps Stalled Wounds Heal
Chronic wounds often get stuck in a cycle of inflammation. The body floods the wound with enzymes called proteases, which are meant to clean up damaged tissue. In a healing wound, these enzymes do their job and taper off. In a chronic wound, they stay elevated and start destroying the new tissue the body is trying to build. The wound essentially tears itself apart faster than it can repair.
Prisma’s collagen and ORC matrix works by physically binding to those excess enzymes, pulling them out of the wound fluid and inactivating them. Research using wound fluid from diabetic foot ulcer patients showed the dressing significantly reduced the activity of several key destructive enzymes compared to standard wet gauze. By lowering the protease levels, the dressing shifts the wound environment from one that breaks tissue down to one that supports new tissue growth.
The Role of Silver
The 1% silver-ORC component is designed to help manage bacteria in the wound. Silver ions are released into the wound bed as the dressing absorbs fluid, providing a barrier against bacterial colonization. Importantly, testing has shown this silver concentration does not harm the skin cells (fibroblasts) responsible for rebuilding tissue, which is a common concern with silver-containing products.
That said, the antimicrobial effect has limits. Lab studies found the dressing had a modest impact on mature bacterial biofilms and was not very effective against MRSA. It performed better against younger, less established bacterial colonies. For wounds with a significant active infection, additional antimicrobial treatment is typically needed alongside the dressing rather than relying on the silver component alone.
What Clinical Studies Show
The largest randomized trial of the collagen/ORC matrix studied 276 patients with diabetic foot ulcers over 12 weeks. Overall, 37% of patients using the dressing achieved complete wound closure compared to 28% using standard moist gauze. That difference, while favoring Prisma, did not reach statistical significance for the full study group.
The more telling finding came from a subgroup analysis. Among patients whose ulcers were less than six months old, 45% healed with the dressing versus 33% with gauze. For ulcers that had persisted six months or longer, healing rates were nearly identical between the two groups (around 19-20%). This suggests Prisma offers the greatest benefit when used on wounds that haven’t yet become deeply entrenched, rather than as a last resort for very long-standing ulcers.
Safety outcomes were equivalent to standard gauze. Both patients and clinicians in the trial reported a strong preference for the Prisma dressing over moistened gauze, likely due to easier handling and the comfort of the gel it forms.
How It Is Applied
Prisma comes as a flat, dry sheet that can be cut to fit the wound. The wound bed needs to be moist for the dressing to work properly, since it relies on absorbing wound fluid to form its gel matrix. If the wound is too dry, it is typically moistened with saline before application. A secondary dressing is placed over the top to keep it in place and manage any excess fluid.
Dressing changes depend on how much fluid the wound produces. Heavily draining wounds may need daily changes, while wounds with less fluid output can go longer between changes. As the dressing absorbs exudate, it gradually breaks down into a gel, so finding a soft, dissolved matrix at dressing change is normal and expected. Any remaining gel is gently rinsed away before a fresh sheet is applied.
Because the dressing is collagen-based, it should not be used in patients with known allergies to collagen or ORC materials, or in wounds with active, heavy bleeding that requires surgical intervention rather than a topical dressing.
Where Prisma Fits in Wound Care
Prisma is not a first-line dressing for simple cuts or acute surgical wounds that are healing normally. Its value is in chronic, stalled wounds where standard moist dressings aren’t producing progress. It fills a specific niche: modifying the wound chemistry to give the body a better chance at doing what it already knows how to do. For wounds under six months old that have adequate blood supply but are simply not closing, the clinical evidence suggests it can meaningfully improve outcomes compared to basic wound care alone.