Methods of tissue decellularization used for preparation of biologic scaffolds and in vivo relevance

Abstract

Biologic scaffolds composed of extracellular matrix (ECM) are widely used in both preclinical animal studies and in many clinical applications to repair and reconstruct tissues. Recently, 3-dimensional ECM constructs have been investigated for use in whole organ engineering applications. ECM scaffolds are prepared by decellularization of mammalian tissues and the ECM provides natural biologic cues that facilitate the restoration of site appropriate and functional tissue. Preservation of the native ECM constituents (i.e., three-dimensional ultrastructure and biochemical composition) during the decellularization process would theoretically result in the ideal scaffold for tissue remodeling. However, all methods of decellularization invariably disrupt the ECM to some degree. Decellularization of tissues and organs for the production of ECM bioscaffolds requires a balance between maintaining native ECM structure and the removal of cellular materials such as DNA, mitochondria, membrane lipids, and cytosolic proteins. These remnant cellular components can elicit an adverse inflammatory response and inhibit constructive remodeling if not adequately removed. Many variables including cell density, matrix density, thickness, and morphology can affect the extent of tissue and organ decellularization and thus the integrity and physical properties of the resulting ECM scaffold. This review describes currently used decellularization techniques, and the effects of these techniques upon the host response to the material.

Chondroinduction from Naturally Derived Cartilage Matrix: A Comparison Between Devitalized and Decellularized Cartilage Encapsulated in Hydrogel Pastes

“…A grain-like appearance was noted only on the DCC and that the DCC microparticles had, in general, smoother surfaces than the DVC microparticles. Because it is known that decellularization can result in changes in matrix architecture and surface ligand landscape, 21 it is possible that these entities were altered in the decellularization process, and thus the decellularization process may have played a role in the reduction of yield stress that we observed. It was noted that the yield stress of DCC microparticles alone was higher than the yield stress of MeHA combined with the DCC, and this reduction in yield stress when MeHA and particles were combined differs from what was noted in previous work, where a 3.4-fold increase was observed in the yield stress of hyaluronic acid nanoparticles combined with MeHA in comparison with the nanoparticles alone, where the MeHA alone had no measurable yield stress.…”

“…20 Therefore, for some cartilage tissue applications, this success with a technology that includes cells brings up the question of whether or not decellularization is even necessary. Although the goal of decellularization is to remove all of the cells without destroying the structure and composition of the ECM, all decellularization processes inevitably cause some disruption to the matrix architecture, orientation, and surface landscape, 21 which may ultimately limit or hinder the chondroinductive potential of the matrix, especially if the decellularization removes or alters the bioactive molecules that are responsible for inducing chondrogenesis.…”

Chemical Decellularization Methods and Its Effects on Extracellular Matrix

“…Hence, it is the most commonly used detergent in decellularization (47,59,65). Although SDS cleaning power is stronger than many other detergents, it also has more destructive effects compared with other detergents (66)(67)(68)(69). A disadvantage of using SDS as a detergent is reducing the amount of GAG and growth factors from the ECM (43).…”

Bioengineering the Pancreas: Cell-on-Scaffold Technology

“…Physical decellularization protocols include several procedures that exploit physical strategies in order to remove cell from ECM, counting temperature-protocols (freeze-thaw cycles), mechanical-protocols (via the agitation and the immersion of samples) and pressure-based protocols [100]. Temperature-based decellularization protocols are relatively simple procedures that only necessitate of multiple freeze-thaw cycles to be effective in cellular removal [101].…”