Collagen preparations in aesthetic medicine

Collagen is a natural fibrillar protein that forms the basis of the connective tissue of the body in humans and animals. It supports the structure of bones, skin, tendons, blood vessels and strengthens tissues, ensuring their strength and elasticity. All collagens are destroyed by the enzyme collagenase. With age, the number of collagen fibers decreases - it loses elasticity, which underlies many external signs of aging.

Used since the early 1980s for facial contouring, collagen injections into wrinkles replenish the collagen matrix and promote external rejuvenation. The effect lasts from several weeks to several months [Glogau R, Narins R, Weiss R. Advances in cosmetic procedures. Fall Clinical Dermatology Conference Supplement Proceedings. Supplement to skin and aging. - 2004. - R. 20–27].

In aesthetic medicine, collagen preparations of animal (bovine, porcine) and non-animal (human) origin are used. Bovine collagen is very similar to human collagen, with a specific difference only in the terminal peptides (telopeptides). These regions are removed during processing, leaving a central protein similar to human protein.

Collagen fillers contain lidocaine and therefore rarely require local anesthesia or nerve block. In addition, lidocaine reduces edema and prevents the formation of ecchymosis by inhibiting eosinophil activation, thereby reducing the risk of hematoma. Most collagen fillers should be stored in the refrigerator [Murray CA, Zloty D, Warshawski L. The evolution of soft tissue fillers in clinical practice. Dermatol Clin. 2005 Apr. 23(2) : 343-63].

Since late 2010, all collagen fillers have been unavailable and withdrawn from the US market.

Animal collagen preparations

Bovine dermal collagen is dispersed in phosphate-buffered saline containing 0.3% lidocaine (eg, Zyderm). This product contains 35 mg/ml and 65 mg/ml highly purified bovine dermal collagen [Cheng JT, Perkins SW, Hamilton MM (2002) Collagen and injectable fillers. Otolaryngol Clin North Am 35(1) : 73–85].

Another preparation (for example, Zyplast) contains bovine collagen cross-linked with glutaraldehyde in a saline solution with 3 mg/ml lidocaine. The connection with glutaraldehyde makes collagen stronger and more resistant to degradation by proteolytic enzymes. Such a microimplant is more durable and binds more water [Elson M. Soft tissue augmentation techniques: Update on available materials. Cosmetic Dermatol (May): 1999. - 13–15].

Bovine collagen preparations are considered an affordable and least expensive treatment option. All dermal filler options in this group contain 95% bovine type I collagen and 5% type III. However, because bovine collagen protein is different from human collagen, allergy is possible - the risk is thought to be 3% [Alam M, Gladstone H, Kramer EM, Murphy JP Jr, Nouri K, Neuhaus IM, et al. ASDS guidelines of care: injectable fillers. Dermatol Surg. 2008 Jun. 34 Suppl 1:S115-48]. Therefore, before starting treatment, it is necessary to carry out two tests: the first - at least six weeks before the start of treatment; the second - in four weeks. The procedure itself can be done no earlier than two weeks after the second negative test.

Allergy test The drug is injected in an amount of 0.1 ml into the superficial layers of the dermis on the anterior surface of the forearm. The result is recorded 48 hours after the injection. The test is considered positive in case of redness, swelling, itching.

Precautions There are two types of adverse reactions: non-allergic and allergic. The former include bruising, granulomatosis, skin necrosis, cyst formation, abscesses, bacterial and herpes infections. The risk of these reactions can be significantly reduced by taking certain precautions.

Thus, patients are advised to stop taking blood thinning drugs (aspirin, non-steroidal anti-inflammatory drugs, vitamin E, warfarin) 10 days before the start of treatment to reduce the risk of hematomas. For patients suffering from herpes, treatment with systemic antiviral drugs should begin 24 hours before the procedure.

Allergic complications are possible even if both intradermal tests were negative. Such allergic reactions last 4-24 months and are corrected by local, intralesional and/or systemic corticosteroids. In such cases, topical use of tacrolimus and systemic use of cyclosporine turned out to be successful [Lowe NJ, Maxwell CA, Patnaik R. Adverse reactions to dermal fillers: review. Dermatol Surg. 2005 Nov. 31(11 Pt 2):1616-25].

Porcine collagen is a dermal filler based on collagen obtained from pork tendons (Evolence). Because pork collagen closely resembles human collagen, the risk of an allergy is so low that a test is usually not necessary. This drug is used to treat moderate to deep wrinkles. As with other collagen fillers, treatment results are immediately visible.

Unlike bovine and bioengineered human collagen fillers, Evolence does not include glutaraldehyde for cross-linking, but instead uses the natural sugar D-ribose. The manufacturer recommends injections into the middle and deep layers of the dermis. The result lasts up to 6 months. [US Food and Drug Administration. Device Approval. US Department of Health and Human Services. Available at www.FDA.gov. Accessed: June 15, 2008].

Precautions Local reactions are extremely rare. Mild swelling, redness and injection pain were the only adverse reactions reported in the literature. Pork collagen preparations should be stored at room temperature.

Collagen preparations of non-animal origin

Collagen isolated from human fibroblast culture (eg, CosmoDerm) is highly purified human collagen dispersed in phosphate-buffered saline containing 0.3% lidocaine. The source is a controlled laboratory culture of human fibroblast cells. [Bisaccia D, Scarborough D. The esthetic correction of the aging mouth. Cosmetic Dermatol (11): 1992. - 8–11].

Another preparation is highly purified human collagen cross-linked with glutaraldehyde and dispersed in phosphate-buffered saline with 0.3% lidocaine solution (for example, CosmoPlast), which is used for deep correction of pronounced defects.

Since these drugs do not contain bovine protein, an allergy test is not required and treatment can be started without delay - even in patients with intolerance to bovine collagen, no cross-allergic reactions have been reported when using bioengineered human collagen [Murray CA, Zloty D, Warshawski L. The evolution of soft tissue fillers in clinical practice. Dermatol Clin. 2005 Apr. 23(2):343-63].

Text: Svetlana Tkachenko, Candidate of Medical Sciences, Associate Professor of the Department of Dermatology, Venereology and Medical Cosmetology, Kharkov National Medical University (Kharkiv).