The Basement Membrane Component of Biologic Scaffolds Derived from Extracellular Matrix

Abstract

The extracellular matrix (ECM) has been successfully used as a scaffold for constructive remodeling of multiple tissues in both preclinical studies and in human clinical applications. The basement membrane is a specialized form of the ECM that supports and facilitates the growth of epithelial cell populations. The morphology and the molecular composition of the ECM, including the basement membrane, vary depending upon the organ from which the ECM is harvested and the methods by which it is processed for use as a medical device. Processing steps, such as decellularization, lyophilization, disinfection, and terminal sterilization, may affect the morphology and composition of an ECM scaffold, including, but not limited to, the integrity of a basement membrane complex. The present study evaluated the presence and integrity of a basement membrane complex in processed ECM derived from three different tissues: the urinary bladder, small intestine, and liver. Immunohistochemical determination of the presence and localization of three basement membrane molecules, collagen IV, laminin, and collagen VII, was conducted for each ECM scaffold. Scanning electron microscopy (SEM) was used to further explore the surface ultrastructure of selected ECM scaffolds. The effect of a surface basement membrane presence upon the pattern of in vitro growth of two separate cell types, NIH 3T3 fibroblasts and human microvascular endothelial cells (HMEC), was also evaluated for each ECM scaffold. Results showed that the only intact basement membrane complex was found on the luminal surface of the ECM derived from the urinary bladder and that the basement membrane was an effective barrier to penetration of the scaffold by the seeded cells. We conclude that the urinary bladder ECM but not the small intestine- or liver-derived ECM contains a surface with composition and morphology consistent with that of an intact basement membrane complex, that the basement membrane complex can survive processing, and that the basement membrane structure can modulate in vitro cell growth patterns.

Preparation of Ex Vivo–Based Biomaterials Using Convective Flow Decellularization

“…2,[4][5][6][7] The general approach used in current decellularization methods is to submerge the tissue in one or more treatment solutions and incubate either statically or expose the tissue to some form of agitation. 8 These decellularization strategies are based mainly on passive diffusion, and commonly require extensive washing steps to not only strip the cellular fragments from the ECM, but also remove solvent residues. Decellularization efficiency is dependent on both tissue thickness and architecture, as the resistance to solvent diffusivity increases when samples are thicker or present a highly dense ECM.…”

“…13 The small intestinal submucosa is processed by physically removing the muscle layer and some portions of the mucosa, followed by chemical treatments to produce an acellular matrix. 8,14,15 More recently, Karim et al 16 used a rotating perfusion bioreactor to decellularize and re-seed porcine heart valves, and Ott et al 17 decellularized whole rat hearts using a modified Langendorff apparatus.…”

Use of a bioscaffold to improve healing of a patellar tendon defect after graft harvest for ACL reconstruction: A study in rabbits

“…Our findings suggest that the luminal side of SIS indeed acted as a barrier to limit cellular infiltration, while the abluminal side of SIS helped cellular proliferation and matrix production. 25,26 The lack of adhesion between the neo-PT and fat pad is of clinical relevance, as the maintenance of patellofemoral kinematics and knee mobilization may be achieved after BPTB graft harvest. Furthermore, the maintenance of relative motion between the PT and fat pad could provide the needed mechanical stimuli for PT healing while concomitantly reducing the deterioration of the remaining medial and lateral portions of the PT.…”

“…24 Further, SIS allows cellular infiltration only through its abluminal side, and thus, can prevent adhesion formation on its luminal side. 25,26 When a single layer of SIS was applied to a gap injury of the rabbit medial collateral ligament (MCL), the healing ligament had better collagen fiber alignment with larger collagen fibril diameters. 22,23 Also, the mechanical properties of the healing MCL were significantly improved with a 33% increase in tangent modulus and a 50% increase in tensile strength.…”

“…Using the right knee of the New Zealand White rabbit as a model, one layer of SIS was placed between the PT defect and the fat pad, and a second layer was placed over the anterior surface of the defect. As SIS has been shown to contain growth factors which can cause chemotaxis and to possess a preferential alignment of collagen fibers which may provide contact guidance to healing tissues, [24][25][26][27] the experiment was designed to test the hypothesis that SIS can cause increased cell proliferation and matrix production as well as improved matrix organization and biomechanical properties of the neo-PT. Secondly, based on the previous literature showing the ability of SIS to prevent cellular infiltration on its luminal side, 25,26 the SIS can serve as a natural barrier in order to limit cellular and vascular infiltration from the fat pad, thus limiting adhesion formation.…”