Collagen-based wrinkle fillers

Bovine injectable collagen (ZyDerm, ZyPlast, etc.) has been around the longest and is the least expensive. Unfortunately, around 3-7 percent (estimates wary widely) of people develop an allergy due to small but important structural differences between human and bovine collagen. As a result, every patient considering bovine collagen treatment requires a skin test to determine sensitivity. Only if no reaction is observed at the injection site after four weeks, the treatment may proceed.

Importantly, people with connective tissue diseases such as rheumatoid arthritis, systemic lupus erythematosus, scleroderma and dermatomyositis appear more likely to develop an allergic reaction to bovine collagen. It is prudent to avoid bovine collagen injections in people with such conditions. There have also been reports of connective tissue disease arising for the first time after bovine collagen injections. However, a causative link between the injections and connective tissue disease has not been established.

Injectable bovine collagen is used mainly for wrinkles of varying depth and depressed scars. The existing range of brands allows to select a product optimal for the size of target wrinkles or scars.

Since collagen is gradually degraded by the body's enzymes, the effects tend to disappear after 3-6 month and the treatment must be repeated to maintain results.

Human collagen

Human injectable collagen (CosmoDerm, CosmoPlast, Autologen, etc.) is similar to bovine collagen in terms of its uses, durability and other properties but has one important advantage: lower risk or allergic and other immune reactions. It does not require allergy testing. However, human collagen tends to be more expensive. The sources vary depending on the brand and include human tissue culture, cadaver tissue obtained at the time of death, and patient's own excess skin removed during cosmetic procedures.

Human acellular dermal matrix

Human acellular dermal matrix is human dermis stripped of all cells and specially treated to increase stability and reduce the risk of immunological reactions. Acellular dermal matrix is typically obtained from the skin of human cadavers. It is tested for diseases (HIV, hepatitis, etc.), treated to remove all cells and other potentially immunogenic elements and processed into an implantable or injectable form. The donor matrix serves not only as a filler but also to provide scaffolding for the recipient's own cells to attach to. This results in better tissues integration and durability. Still, since dermal matrix consists primarily of collagen, it is gradually broken down by collagen-digesting enzymes.

Human acellular dermal matrix comes either as a sheet (AlloDerm) or small particle suspension (Cymetra a.k.a. Micronized AlloDerm). The sheet is more durable (1-2 years or longer) and is suitable for repairing substantial imperfections, such as deep lines, folds and furrows. However, it requires implantation via a small incision. The suspension can be injected but lasts only about 6 month on average, i.e. only slightly longer than conventional bovine collagen. It is used mainly for problems like medium wrinkles, lines and pitted scars.

Fibroblast injections

Collagen injections, whether bovine or human, have an important drawback: injected collagen is gradually broken up by the proteolytic enzymes and can only be replenished by more injections. An interesting new approach is to inject collagen-producing cells (fibroblasts) instead of collagen itself. If the injected fibroblasts take hold in your skin, they can keep producing collagen for a long time. However, the use of fibroblasts from donor skin is difficult because of tissue rejection problems. (You wouldn't want to take immunosupressive drugs just to soften your wrinkles, would you?). One currently available alternative (patented under the brand name Isolagen) is to harvest the patient's own fibroblasts (from a small skin sample), grow them in tissues culture and then inject into wrinkles and scars. For information on the proc and cons of this method, see our article on autologous transplant-based fillers and the fact-sheet on cultured fibroblasts (Isolagen).

Acellular human cadaveric dermis (AlloDerm)
Micronized acellular human cadaveric dermis (Cymetra, Micronized AlloDerm)
Autologous human collagen (Autologen)
Cultured autologous human fibroblasts (Isolagen)