Properties of the amniotic membrane for potential use in tissue engineering

Abstract

An important component of tissue engineering (TE) is the supporting matrix upon which cells and tissues grow, also known as the scaffold. Scaffolds must easily integrate with host tissue and provide an excellent environment for cell growth and differentiation. Most scaffold materials are naturally derived from mammalian tissues. The amniotic membrane (AM) is considered an important potential source for scaffolding material. The AM represents the innermost layer of the placenta and is composed of a single epithelial layer, a thick basement membrane and an avascular stroma. The special structure and biological viability of the AM allows it to be an ideal candidate for creating scaffolds used in TE. Epithelial cells derived from the AM have the advantages of stem cells, yet are a more suitable source of cells for TE than stem cells. The extracellular matrix components of the basement membrane of the AM create an almost native scaffold for cell seeding in TE. In addition, the AM has other biological properties important for TE, including anti-inflammatory, anti-microbial, anti-fibrosis, anti-scarring, as well as reasonable mechanical property and low immunogenicity. In this review, the various properties of the AM are discussed in light of their potential use for TE.

Histologic changes of the fetal membranes after fetoscopic laser surgery for twin-twin transfusion syndrome

“…The amniotic layer of the fetal membranes is made up of a lining of cuboidal epithelial cells attached to a thick basement membrane over a collagenous matrix with a fibroblast layer. The outermost layer is the chorion, comprised of a layer of extravillous trophoblasts (cEVTs) embedded in a loose stroma with minimal amounts of collagen (12,13). A shared histological feature of both structures is their lack of vascular supply implying that in any event of injury the process of healing cannot follow traditional mechanisms of repair (13).…”

“…The outermost layer is the chorion, comprised of a layer of extravillous trophoblasts (cEVTs) embedded in a loose stroma with minimal amounts of collagen (12,13). A shared histological feature of both structures is their lack of vascular supply implying that in any event of injury the process of healing cannot follow traditional mechanisms of repair (13). Although not specifically tested, it then becomes more natural for fetal membranes to follow the repair sequence of other avascular human tissues such as cornea and tympanic membrane where the key event is the migration of the epithelium adjacent to the site of injury across the defect (14)(15)(16).…”

Repair of Oronasal Fistulae by Interposition of Multilayered Amniotic Membrane Allograft

“…39 It exhibits anti-inflammatory effects and has low immunogenicity. 40 This study reports the first The axis of the ordinates shows the mean degree of local redness in all animals of a group. The axis of the abscissas displays postoperative days (POD) 3, 7, 10, and 76.…”

Rolling the Human Amnion to Engineer Laminated Vascular Tissues

“…The hAM is an abundant birthing tissue that, due to its unique structure, composition, and neonatal derivation, has had promising results when used in a number of tissue repair applications. [11][12][13][14][15][16][17]33 Based on these clinical successes and a novel approach that takes advantage of the hAM's unique properties, we have developed a concentric rolling approach that aims at rapidly forming cell-dense and mechanically stable tissue-engineered blood vessels.…”

“…[11][12][13][14][15][16][17] However, all these applications have used the hAM as an acellular material, without taking advantage of the material's capacity to be seeded or used as a layered construct to speed and potentially enhance tissue regeneration. The hAM presents a number of desirable characteristics (advantageous for blood vessel regeneration and a wide range of tissue-engineering applications), including biocompatibility, biostability, noninflammatory, nontoxic, noncarcinogenic, nonimmunogenic, 17 vasoactivity, thromboresistance, 18 ability to remodel, 16 infection resistance, suture-holding capacity, 19 and its wide availability.…”