Enhancing cell migration in shape-memory alginate–collagen composite scaffolds: In vitro and ex vivo assessment for intervertebral disc repair

Abstract

Lower lumbar disc disorders pose a significant problem in an ageing society with substantial socioeconomic consequences. Both inner tissue (nucleus pulposus, NP) and outer tissue (annulus fibrosus, AF) of the intervertebral disc (IVD) are affected by such debilitating disorders and can lead to disc herniation and lower back pain. In this study, we developed an alginate-collagen composite porous scaffold with shape-memory properties to fill defects occurring in AF tissue of degenerated IVDs, which has the potential to be administered using minimal invasive surgery. In the first part of this work we assessed how collagen incorporation on pre-formed alginate scaffolds influences the physical properties of the final composite scaffold. We also evaluated the ability of AF cells to attach, migrate and proliferate on the composite alginate-collagen scaffolds compared to control scaffolds (alginate only). In vitro experiments, performed in IVD-like microenvironmental conditions (low glucose and low oxygen concentrations), revealed that for alginate only scaffolds, AF cells agglomerated in clusters with limited infiltration and migration capacity. In comparison, for alginatecollagen scaffolds, AF cells readily attached and colonized constructs, while preserving their typical fibroblastic-like cell morphology with spreading behavior and intense cytoskeleton expression. In a second part of this study, we investigated the effects of alginate-collagen scaffold when seeded with bone marrow derived mesenchymal stem cells (MSCs). In vitro, we observed that alginate-collagen porous scaffolds supported cell proliferation and extracellular matrix (ECM) deposition (collagen type I); which secretion was amplified by the local release of TGF-ß3. In addition, when cultured in ex vivo organ defect model, alginatecollagen scaffolds maintained viability of transplanted MSCs for up to 5 weeks. Taken together, these findings illustrate the advantages of incorporating collagen as a means to enhance cell migration and proliferation in porous scaffolds which could be used to augment tissue repair strategies.

In situ repair of bone and cartilage defects using 3D scanning and 3D printing

“…Suitable biomaterials and stimulating factors, which could recruit stem cells from bone marrow and synovialis 13 , 23 , are important component of bioink for 3D bioprinting. Several studies confirmed that alginate combined with bone morphogenetic protein 2 (BMP-2), collagen, and oligosaccharides plays vital roles in bone cell proliferation, migration, and differentiation 24 – 28 . HA hydrogel with different molecular weight could facilitate cell migration and modulate cell proliferation 29 – 31 .…”

Development of a bovine decellularized extracellular matrix-biomaterial for nucleus pulposus regeneration

“…Collagen and GAGs are the main ECM protein components of the NP, which are important for determining cellular behavior such as proliferation, differentiation, migration and maturation . Decellularization of the ECM resulted in a loose structure of the matrix within the small tissue fragments (Fig.…”

3D Bioprinting of Developmentally Inspired Templates for Whole Bone Organ Engineering

“…Cell viability was assessed after 24 h using a LIVE/DEAD™ viability/cytotoxicity assay kit as previously described [45] . Live dead quantification was carried out using image J.…”