Understanding cell homing-based tissue regeneration from the perspective of materials

Abstract

Homing of cells to their target organs for tissue defect repair poses a significant challenge to biomaterials scientists and tissue engineers, due to the low efficiency of homing of effective cells to defect sites as well as the difficulties in coordinating cell migration, adhesion, spreading and differentiations. Recent advances in biomaterials have successfully improved the efficiency of homing of mesenchymal stem cells (MSCs) and cell homing-based tissue regeneration. In this review, the process of cell-homing based tissue regeneration was discussed from three different perspectives, including cell surface engineering, scaffold optimization and signaling molecules interactions. Cell surface modification by using polymeric materials offers a simple way to administrate cell migration. Besides, the ordered or anisotropic structures are proved to be more efficient for cell adhesion, spreading and infiltration than relatively random or isotropy structures. Moreover, the coordinated release of different growth factors (GFs), e.g. achieved via core-shell microspheres, can orchestrate the biological processes, including cell growth and differentiations, and significantly enhance the osteogenic differentiation of low population density of MSCs. These developments in biomaterials are not only important for fundamental understanding of materials-cell interactions, but also help understand cell homing-based tissue regeneration from the perspective of materials, which is crucial for the design and fabrication of a new generation of highly functional biomaterials for tissue regeneration.

Engineering a Cell Home for Stem Cell Homing and Accommodation

“…In this context, materials have to offer informative microenvironments that mimic a physiological niche in the sense that their intrinsic nature and structure will transmit beneficial signals that host stem cells may respond, read, and decode; accordingly, these cells will target their terminal to the implanted materials. Thereafter, these cells modify their behavior and fate in response to the local signals as well as the physicochemical cues rendered by the materials . Therefore, a suitable material device can be used as a home that offers an optimum microenvironmental condition to cells, as a template to instruct new tissue reorganization, and as a vehicle to deliver bioactive cargoes that can be released in a controlled manner, thus leading to a local artificial niche that orchestrates cell behavior and ensures in situ tissue remodeling and regeneration …”

“…The marriage of cell biology with advanced biomaterials approaches provides the possibility of furthering our basic knowledge of niche composition and how components control stem cells to expand new regenerative technologies . Meanwhile, as the driving force in tissue engineering, biomimicry has sparked a large number of biological innovations over the years and has inspired many cutting‐edge material designs to mimic multiple naturally occurring ECM components, if not all aspects of the niche . Together with the rapid progress of bioengineering and the fast expansion of knowledge, biomimicry could move the field of regenerative medicine forward at a deeper level.…”

“…Together with the rapid progress of bioengineering and the fast expansion of knowledge, biomimicry could move the field of regenerative medicine forward at a deeper level. Although refinement and ameliorations are still desired, many of the described biomaterials or biotechnologies can be envisaged in the near future to pattern relevant biochemical and biophysical features with a specific distribution, converging into the realization of directing cell homing and function within the in situ reparative process at the injury areas …”

The Critical Role of Cell Homing in Cytotherapeutics and Regenerative Medicine

“…For instance, approximately 10 9 functional stem cells are required to repair a small part (1/3) of the left ventricle by regenerating the diseased tissue following myocardial infarction . Homing of a large number of cells to their target sites for tissue repair poses a significant challenge due not only to a low homing efficiency but also to difficulties in coordinating cell movement, repopulation, and gene expression . Nevertheless, recruitment of the patient's own reparative cells into a porous biomaterial transplanted at the site of insult as part of a wound repair strategy has been extensively investigated 9b,10b.…”

Administration of signalling molecules dictates stem cell homing for in situ regeneration

“…Intravital microscopy can visualize labelled cells in a given tissue or organ after surgical dissection, thus revealing the in vivo chemokine‐directed interactions between MSCs and the endothelium and the subsequent cell migration within the ECM . However, we still cannot identify native MSCs and track their chemotaxis in situ , and the actual roles of endogenously recruited cell populations in tissue regeneration remain unclear . Advancements in in vitro and in vivo model investigations will be rewarded with increased potential across the arena of stem cell biology and therapy .…”