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Biomaterial-assisted stem cell therapies hold immense promise for regenerative medicine, yet clinical translation remains challenging. This review focuses on recent advances and persistent limitations in applying induced pluripotent stem cells (iPSCs), endothelial colony-forming cells (ECFCs), multipotent mesenchymal stromal cells (MSCs), and embryonic stem cells (ESCs) within engineered microenvironments. We introduce a novel “bottom-up” approach to biomaterial design. This approach focuses first on understanding the fundamental biological properties and microenvironmental needs of stem cells, then engineering cell-instructive biomaterials to support them. Unlike conventional methods that adapt cells to pre-existing materials, this strategy prioritizes designing biomaterials from the molecular level upward to address key challenges, including differentiation variability, incomplete matching of iPSCs to somatic counterparts, functional maturity of derived cells, and survival of ECFCs/MSCs in therapeutic niches. By replicating lineage-specific mechanical, chemical, and spatial cues, these tailored biomaterials enhance differentiation fidelity, reprogramming efficiency, and functional integration. This paradigm shift from passive scaffolds to dynamic, cell-instructive platforms bridges critical gaps between laboratory success and clinical translation, offering a transformative roadmap for regenerative medicine and tissue engineering. 

Introduction: Generating new lymphatic vessels has been postulated as an innovative therapeutic strategy for various disease phenotypes, including neurodegenerative diseases, metabolic syndrome, cardiovascular disease, and lymphedema. Yet, compared to the blood vascular system, protocols to differentiate human induced pluripotent stem cells (hiPSCs) into lymphatic endothelial cells (LECs) are still lacking. Methods: Transcription factors, ETS2 and ETV2 are key regulators of embryonic vascular development, including lymphatic specification. While ETV2 has been shown to efficiently generate blood endothelial cells, little is known about ETS2 and its role in lymphatic differentiation. Here, we describe a method for rapid and efficient generation of LECs using transcription factors, ETS2 and ETV2. Results: This approach reproducibly differentiates four diverse hiPSCs into LECs with exceedingly high efficiency. Timely activation of ETS2 was critical, to enable its interaction with Prox1, a master lymphatic regulator. Differentiated LECs express key lymphatic markers, VEGFR3, LYVE-1, and Podoplanin, in comparable levels to mature LECs. The differentiated LECs are able to assemble into stable lymphatic vascular networks in vitro, and secrete key lymphangiocrine, reelin. Conclusion: Overall, our protocol has broad applications for basic study of lymphatic biology, as well as toward various approaches in lymphatic regeneration and personalized medicine. 

The role of the circulatory system, containing the blood and lymphatic vasculatures, within the body, has become increasingly focused on by researchers as dysfunction of either of the systems has been linked to serious complications and disease. Currently, in vivo models are unable to provide the sufficient monitoring and level of manipulation needed to characterize the fluidic dynamics of the microcirculation in blood and lymphatic vessels; thus in vitro models have been pursued as an alternative model. Microfluidic devices have the required properties to provide a physiologically relevant circulatory system model for research as well as the experimental tools to conduct more advanced research analyses of microcirculation flow. In this review paper, the physiological behavior of fluid flow and electrical communication within the endothelial cells of the systems are detailed and discussed to highlight their complexities. Cell co-culturing methods and other relevant organ-on-a-chip devices will be evaluated to demonstrate the feasibility and relevance of the in vitro microfluidic model. Microfluidic systems will be determined as a noteworthy model that can display physiologically relevant flow of the cardiovascular and lymphatic systems, which will enable researchers to investigate the systems' prevalence in diseases and identify potential therapeutics. 

Surface coating with dopamine conjugated hyaluronic acid (HA–DP) can interact with lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) to preserve the phenotypes and functionality of lymphatic endothelial cells (LECs). 

Abstract Spatial patterning of different cell types is crucial for tissue engineering and is characterized by the formation of sharp boundary between segregated groups of cells of different lineages. The cell−cell boundary layers, depending on the relative adhesion forces, can result in kinks in the border, similar to fingering patterns between two viscous partially miscible fluids which can be characterized by its fractal dimension. This suggests that mathematical models used to analyze the fingering patterns can be applied to cell migration data as a metric for intercellular adhesion forces. In this study, we develop a novel computational analysis method to characterize the interactions between blood endothelial cells (BECs) and lymphatic endothelial cells (LECs), which form segregated vasculature by recognizing each other through podoplanin. We observed indiscriminate mixing with LEC−LEC and BEC−BEC pairs and a sharp boundary between LEC−BEC pair, and fingering-like patterns with pseudo-LEC−BEC pairs. We found that the box counting method yields fractal dimension between 1 for sharp boundaries and 1.3 for indiscriminate mixing, and intermediate values for fingering-like boundaries. We further verify that these results are due to differential affinity by performing random walk simulations with differential attraction to nearby cells and generate similar migration pattern, confirming that higher differential attraction between different cell types result in lower fractal dimensions. We estimate the characteristic velocity and interfacial tension for our simulated and experimental data to show that the fractal dimension negatively correlates with capillary number (Ca), further indicating that the mathematical models used to study viscous fingering pattern can be used to characterize cell−cell mixing. Taken together, these results indicate that the fractal analysis of segregation boundaries can be used as a simple metric to estimate relative cell−cell adhesion forces between different cell types. 

Encapsulation of single cells in a thin hydrogel provides a more precise control of stem cell niches and better molecular transport. Despite the recent advances in microfluidic technologies to allow encapsulation of single cells, existing methods rely on special crosslinking agents that are pre-coated on the cell surface and subject to the variation of the cell membrane, which limits their widespread adoption. This work reports a high-throughput single-cell encapsulation method based on the “tip streaming” mode of alternating current (AC) electrospray, with encapsulation efficiencies over 80% after tuned centrifugation. Dripping with multiple cells is curtailed due to gating by the sharp conic meniscus of the tip streaming mode that only allows one cell to be ejected at a time. Moreover, the method can be universally applied to both natural and synthetic hydrogels, as well as various cell types, including human multipotent mesenchymal stromal cells (hMSCs). Encapsulated hMSCs maintain good cell viability over an extended culture period and exhibit robust differentiation potential into osteoblasts and adipocytes. Collectively, electrically induced tip streaming enables high-throughput encapsulation of single cells with high efficiency and universality, which is applicable for various applications in cell therapy, pharmacokinetic studies, and regenerative medicine. 

Abstract Granular hydrogels show great promise in biomedical applications by mimicking the extracellular matrix and fostering a supportive microenvironment for tissue regeneration. This study investigates how tuning granular hydrogel properties influences lymphatic tube formation. Microgels were fabricated using norbornene‐modified hyaluronic acid (NorHA) via pipetting or vortexing for 90 s (V90s) and 180 s (V180s), then assembled into granular hydrogels under loose and tight packing conditions. These conditions produced gels with varied pore morphologies and bulk rheological properties. Lymphatic capillary formation occurred only in tightly packed gels, where mechanical properties converged, highlighting the importance of gel morphology over stiffness. V180s samples showed earlier vessel formation as seen in lymphatic gene and protein expression, while pipetted gels exhibited greater capillary connectivity, forming larger vessel clusters and fewer small satellite structures. The pipetting gels also supported lower‐curvature, more linear capillary networks that bridged multiple droplets, likely due to reduced entrapment in large voids compared to vortexed gels. These findings suggest that in bulk granular gels, lymphatic tube formation is governed not by mechanical stiffness but by pore size and gel topology (periodicity). Understanding and optimizing these morphological parameters can inform future strategies in lymphatic tissue engineering and regenerative medicine.