Encapsulation of Human Spinal Cord Progenitor Cells in Hyaluronan-Gelatin Hydrogel for Spinal Cord Injury Treatment

Epithelial-Mesenchymal Transition of Cancer Cells on Micropillar Arrays

Epithelial-mesenchymal transition (EMT) is critical for tumor invasion and many other cell-relevant processes. While much progress has been made about EMT, no report concerns the EMT of cells on topological biomaterial interfaces with significant nuclear deformation. Herein, we prepared a poly(lactide-co-glycolide) micropillar array with an appropriate dimension to enable significant deformation of cell nuclei and examined EMT of a human lung cancer epithelial cell (A549). We show that A549 cells undergo serious nuclear deformation on the micropillar array. The cells express more E-cadherin and less vimentin on the micropillar array than on the smooth surface. After transforming growth factor-β1 (TGF-β1) treatment, the expression of E-cadherin as an indicator of the epithelial phenotype is decreased and the expression of vimentin as an indicator of the mesenchymal phenotype is increased for the cells both on smooth surfaces and on micropillar arrays, indicating that EMT occurs even when the cell nuclei are deformed and the culture on the micropillar array more enhances the expression of vimentin. Expression of myosin phosphatase targeting subunit 1 is reduced in the cells on the micropillar array, possibly affecting the turnover of myosin light chain phosphorylation and actin assembly; this makes cells on the micropillar array prefer the epithelial-like phenotype and more sensitive to TGF-β1. Overall, the micropillar array exhibits a promoting effect on the EMT.

Induced Pluripotent Stem Cells and Organoids in Advancing Neuropathology Research and Therapies

This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant potential for regenerative therapy and drug discovery. The adaptability of iPSCs, along with associated methodologies, enables the generation of various types of neural cell differentiations and their integration into three-dimensional organoid models, effectively replicating complex tissue structures in vitro. Key advancements in organoid and iPSC generation protocols, alongside the careful selection of donor cell types, are emphasized as critical steps in harnessing these technologies to mitigate tumorigenic risks and other hurdles. Encouragingly, iPSCs show promising outcomes in regenerative therapies, as evidenced by their successful application in animal models.

Reactive Oxygen Species Scavenging Injectable Hydrogel Potentiates the Therapeutic Potential of Mesenchymal Stem Cells in Skin Flap Regeneration

Cell-based therapies offer tremendous potential for skin flap regeneration. However, the hostile microenvironment of the injured tissue adversely affects the longevity and paracrine effects of the implanted cells, severely reducing their therapeutic effectiveness. Here, an injectable hydrogel (nGk) with reactive oxygen species (ROS) scavenging capability, which can amplify the cell viability and functions of encapsulated mesenchymal stem cells (MSCs), is employed to promote skin flap repair. nGk is formulated by dispersing manganese dioxide nanoparticles (MnO2 NPs) in a gelatin/κ-carrageenan hydrogel, which exhibits satisfactory injectable properties and undergoes a sol-gel phase transition at around 40 °C, leading to the formation of a solid gel at physiological temperature. MnO2 NPs enhance the mechanical properties of the hydrogel and give it the ability to scavenge ROS, thus providing a cell-protective system for MSCs. Cell culture studies show that nGk can mitigate the oxidative stress, improve cell viability, and boost stem cell paracrine function to promote angiogenesis. Furthermore, MSC-loaded nGk (nGk@MSCs) can improve the survival of skin flaps by promoting angiogenesis, reducing inflammatory reactions, and attenuating necrosis, providing an effective approach for tissue regeneration. Collectively, injectable nGk has substantial potential to enhance the therapeutic benefits of MSCs, making it a valuable delivery system for cell-based therapies.

Cell cycle control by cell-matrix interactions

Cell adhesion to the extracellular matrix (ECM) is required for normal cell cycle progression and accurate cell division. However, how cell adhesion to the wide range of ECM proteins found in human tissues influences the cell cycle is not fully understood. The composition and physical properties of the ECM can have profound effects on cell proliferation but can also promote cell cycle exit and quiescence. Furthermore, during tumor development and progression, changes in the ECM can drive both cancer cell proliferation and dormancy. Cell-matrix adhesion is primarily sensed via integrin-associated adhesion complexes, which in turn are regulated by the cell cycle machinery. In particular, cyclin-dependent kinase 1 (CDK1) has been shown to play a crucial role in regulating adhesion complexes during interphase and entry into mitosis. These reciprocal links between cell cycle progression and cell-matrix interactions are now being identified.