AmnioMatrix

For decades, amniotic tissue has been studied and recognized as an effective biological dressing for burns and wounds due to its capacity to prevent contamination and infection of soft tissue injury and observations of its ability to accelerate wound healing and tissue repair (Gruss & Jirsch, 1978). Amniotic tissue has since been confirmed to contain a biological cocktail of cellular factors believed to be relevant to wound healing processes (Steed, et al., 2008).

Based on extensions of this research, AmnioMatrix™ is a cryo-preserved (frozen) complex of amniotic tissue that has been developed and approved by the Federal Drug Administration (FDA) as a liquid human allograft used in the treatment of soft-tissue defects and areas of local inflammation which may cause pain (Applied Biologics, 2011). An allograft refers to tissue transplanted from one individual human to another. The producers of AmnioMatrix™ have reported successful use of the product in the localized treatment of soft tissue pathology, in which a tear, injury or wound exists (Applied Biologics, 2011). Reported uses include the treatment of:

  • Skin and soft tissue ulcerations
  • Plantar fasciitis
  • Muscle tears and other soft tissue injuries
  • Repetitive motion/overuse injuries
  • Tendinopathies
  • Bone injuries resistant to healing
  • Arthritis
  • Failed back surgery syndrome due to epidural scar formation

AmnioMatrix tissue is most commonly used as a filling agent for soft tissue injuries, hollow regions of bone, and as an anti-inflammatory wound dressing. It is indicated to promote the healing of these injuries, as well as improve any associated pain.

Anatomy

During fetal development, the fetus is surrounded by two membranous structures: a translucent innermost amnion layer attached to the developing fetus, and an outer chorion layer, which attaches to maternal structures (Guller, 2012). Over the course of pregnancy, these layers become fused, and the space between the fetus and the amnion fills with fluid, becoming the amniotic sac. The fluid that fills the amniotic sac originates from the mother’s blood plasma and is mostly water, mixed with some macronutrients (proteins, carbohydrates, lipids) and micronutrients (electrolytes, urea, hyaluronic acid) (Ross & Beall, 2011). When labor reaches term and a woman’s “water breaks,” it is the amniotic sac that has spontaneously ruptured.

The amniotic sac serves to protect and nourish the developing fetus. A fetus will both inhale and swallow amniotic fluid throughout its time in the womb. Nutrients and growth factors in the amniotic fluid are critical to normal lung development, and when swallowed, contribute to the formation of fetal urine (Ross & Beall, 2011). Protection comes in the form of fluid cushioning which diminishes forces applied to the mother’s abdomen and allows for fetal movement within the womb — critical for musculoskeletal development.

During pregnancy, amniotic fluid from the sac can be collected and analyzed for fetal cells to track certain data and information pertaining to the health of the unborn child. When amniotic fluid is collected through the mother’s abdomen and the amniotic membrane via needle, the procedure is termed amniocentesis, and is valuable for detecting genetic defects, fetal infection and fetal lung maturity (Ghidini, 2012). Amniocentesis can also detect abnormal levels of amniotic fluid; either too much or too little amniotic fluid can lead to potential life-threatening complications for the child (Ross & Beall, 2011).

Studies have discovered that amniotic fluid contains significant quantities of fetal stem cells, or amniotic stem cells, which hold the potential for many revolutionary medical applications. These stem cells are termed multipotent, which signifies their ability to differentiate into many different tissues found throughout the body; tissues which include skin, cartilage, nerves, muscle and bone. Amniotic tissue also contains significant quantities of the protein collagen, as well as other nutrients and growth factors which allow it to be an ideal scaffold for tissue repair and cellular proliferation. AmnioMatrix™ is created from the collection and cryo-preservation of this amniotic tissue, directly in conjunction with scheduled cesarean sections (Applied Biologics, 2011).

For ethical considerations, it is important to note that amniotic stem cells are not embryonic stem cells, and amniotic tissue is collected with a very small risk of harming an embryo or the mother.

Procedure

Prior to the procedure, amniotic tissue is collected, cryo-preserved and stored as the AmnioMatrix™ product until ready for use.
The procedure for AmnioMatrix™ treatment is dependent upon the nature of the injury. For pain due to bone or deep soft tissue injury, an injection site that allows adequate access to the injury is determined. The injection site can then be prepared, sterilized and numbed with a local anesthetic before a needle is inserted to the site of injury to deliver the AmnioMatrix™ tissue. The needle may be guided by ultrasound or another imaging modality. For more superficial injuries, such as with ulcers, burns and wounds, AmnioMatrix™ may be applied topically on the surface as an anti-inflammatory and anti-microbial dressing to promote healing and reduce pain.

Under certain medical circumstances, most notably a weakened immune system from disease or medical therapy, AmnioMatrix™ may be contraindicated (Applied Biologics, 2011). Patients should discuss such conditions with the treating physician.

Benefits

AmnioMatrix™ offers the possibility to treat a wide variety of tissue injuries, but just as importantly, has been shown to help reduce the pain associated with these injuries.

In many cases, patients will experience relief from pain and injury repair with just one treatment of AmnioMatrix™ therapy; however, multiple treatments may be necessary depending on the nature and extent of the injury (Applied Biologics, 2011).

Risks

Because AmnioMatrix ™ has been developed from homologous human tissue, there is a risk of allergic reaction to the foreign tissue, or transmission of a communicable disease from the donor. But since the cryo-preserved tissue is selected from screened, healthy donors, this risk is fairly small (Applied Biologics, 2011).

For injections, complications tend to be rare, and when they do occur, they tend to be mild. Potential complications of deep injection can include post-procedural pain, bleeding or infection.

Outcomes

AmnioMatrix™ is a relatively new medical therapy, and is based largely on an extension of research into the restorative nature of amniotic tissue. Because of this, evidence for its benefit is limited to a few small trials and case reports, however this base of evidence will grow and AmnioMatrix™ continues to be utilized in medical applications.

Individual case reports have shown AmnioMatrix™ to be an effective therapy from conditions ranging from Achilles tendonitis to small fractures of bones within the foot. A small clinical trial sponsored by the creators of AmnioMatrix™ showed great promise in the treatment of treatment-resistant wounds; 18 of the 19 patients in the study reached successful wound closure with 100% improvement regardless of wound origin (Applied Biologics, 2004). A similar study on the healing of leg ulcers showed a significant healing response for 80% of patients, with a significant reduction in pain rapidly after administration of amniotic tissue (Mermet, et al., 2007). Animal studies have shown amniotic tissue to be promising toward reducing epidural adhesions, or scar tissue, that commonly causes pain following back surgery (Tao & Fan, 2009). These findings were confirmed in a human trial shortly thereafter (Ploska, 2010).

From these small trials and individual case reports, outcomes following the use of amniotic tissue have been positive, although significantly more research remains to be conducted.

References

Applied Biologics. (2004). AMNIOMATRIX & CHRONIC WOUND MANAGEMENT TWELVE WEEK CLINICAL OUTCOME. Retrieved from http://www.dfcon.com/abstracts2012/47.pdf
Applied Biologics. (2011). Amniomatrix FAQ. Retrieved from Applied Biologics Website: http://www.appliedbiologics.com/index.php/frequently-asked-questions
Ghidini, A. (2012). Diagnostic amniocentesis. Retrieved from In: UpToDate, Basow. DS (Ed), Waltham, MA.
Gruss, J., & Jirsch, D. (1978). Human amniotic membrane: a versatile wound dressing. CMA Journal , 1237-1254.
Guller, S. (2012). Fetal membranes: Anatomy and biochemistry. Retrieved from In: UpToDate, Basow. DS (Ed), Waltham, MA.
Mermet, I., & al., e. (2007). Use of amniotic membrane transplantation in the treatment of venous leg ulcers. Wound Rep Reg , 459-464.
Ploska, P. (2010). Summary of Clinical Outcome related to the Use of Human Amnion Tissue Allograft in Right L4-L5 Decompression Procedure. Retrieved from Clinical Abstract. Applied Biologics: http://appliedbiologics.com/images/pub/ploska.pdf
Ross, M., & Beall, M. (2011). Physiology of amniotic fluid volume regulation. Retrieved from In: UpToDate, Basow. DS (Ed), Waltham, MA.
Steed, D., & al., e. (2008). Amnion-derived Cellular Cytokine Solution. Eplasty .
Tao, H., & Fan, H. (2009). Implantation of amniotic membrane to reduce post-laminectomy epidural adhesions. Eur Spine J .