Recent progress in stem cell differentiation directed by material and mechanical cues

Abstract

Stem cells play essential roles in tissue regeneration in vivo via specific lineage differentiation induced by environmental factors. In the past, biochemical signals were the focus of induced stem cell differentiation. As reported by Engler et al (2006 Cell 126 677-89), biophysical signal mediated stem cell differentiation could also serve as an important inducer. With the advancement of material science, it becomes a possible strategy to generate active biophysical signals for directing stem cell fate through specially designed material microstructures. In the past five years, significant progress has been made in this field, and these designed biophysical signals include material elasticity/rigidity, micropatterned structure, extracellular matrix (ECM) coated materials, material transmitted extracellular mechanical force etc. A large number of investigations involved material directed differentiation of mesenchymal stem cells, neural stem/progenitor cells, adipose derived stem cells, hematopoietic stem/progenitor cells, embryonic stem cells and other cells. Hydrogel based materials were commonly used to create varied mechanical properties via modifying the ratio of different components, crosslinking levels, matrix concentration and conjugation with other components. Among them, polyacrylamide (PAM) and polydimethylsiloxane (PDMS) hydrogels remained the major types of material. Specially designed micropatterning was not only able to create a unique topographical surface to control cell shape, alignment, cell-cell and cell-matrix contact for basic stem cell biology study, but also could be integrated with 3D bioprinting to generate micropattered 3D structure and thus to induce stem cell based tissue regeneration. ECM coating on a specific topographical structure was capable of inducing even more specific and potent stem cell differentiation along with soluble factors and mechanical force. The article overviews the progress of the past five years in this particular field.

Mechanical characterization of human brain tumors from patients and comparison to potential surgical phantoms

“…Polyacrylamide and polydimethylsiloxane (PDMS) are often used for 2D studies, while polyethylene-glycol (PEG) and collagen are often used to encapsulate cells in 3D (see exemplary review by Lin et al[46]). Collagen hydrogels have been used readily for nervous tissue scaffolds and neural tissue engineering[47–51], and a recent example from Wang et al demonstrates the utility of biomimetic hydrogels to study the effects of ECM stiffness on glioblastoma cells proliferation and subsequent remodeling of the 3D hydrogel [52].…”

Biofabrication and Bone Tissue Regeneration: Cell Source, Approaches, and Challenges

“…ECM coating on a definite topographical structure is able to induce even more precise and powerful stem cell differentiation along with soluble factors and mechanical forces (Lin et al, 2016). …”

Cell studies of hybridized carbon nanofibers containing bioactive glass nanoparticles using bone mesenchymal stromal cells

“…Cell proliferation and differentiation were influenced by many factors including material composition, topographical cue and soluble components23243334. For the prepared CNF/BG hybrids and pure CNF in this study, they were nanofibrous constructs, which favored the cell attachment and proliferation because they mimicked the three dimensional structure of natural ECM35.…”