An official website of the United States government
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.
more »
« less
Overcoming big bottlenecks in vascular regeneration
Abstract Bioengineering and regenerative medicine strategies are promising for the treatment of vascular diseases. However, current limitations inhibit the ability of these approaches to be translated to clinical practice. Here we summarize some of the big bottlenecks that inhibit vascular regeneration in the disease applications of aortic aneurysms, stroke, and peripheral artery disease. We also describe the bottlenecks preventing three-dimensional bioprinting of vascular networks for tissue engineering applications. Finally, we describe emerging technologies and opportunities to overcome these challenges to advance vascular regeneration.
more »
« less
- PAR ID:
- 10524316
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Communications Biology
- Volume:
- 7
- Issue:
- 1
- ISSN:
- 2399-3642
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract A new approach is described for fabricating 3D poly(ε‐caprolactone) (PCL)/gelatin (1:1) nanofiber aerogels with patterned macrochannels and anisotropic microchannels by freeze‐casting with 3D‐printed sacrificial templates. Single layer or multiple layers of macrochannels are formed through an inverse replica of 3D‐printed templates. Aligned microchannels formed by partially anisotropic freezing act as interconnected pores between templated macrochannels. The resulting macro‐/microchannels within nanofiber aerogels significantly increase preosteoblast infiltration in vitro. The conjugation of vascular endothelial growth factor (VEGF)‐mimicking QK peptide to PCL/gelatin/gelatin methacryloyl (1:0.5:0.5) nanofiber aerogels with patterned macrochannels promotes the formation of a microvascular network of seeded human microvascular endothelial cells. Moreover, nanofiber aerogels with patterned macrochannels and anisotropic microchannels show significantly enhanced cellular infiltration rates and host tissue integration compared to aerogels without macrochannels following subcutaneous implantation in rats. Taken together, this novel class of nanofiber aerogels holds great potential in biomedical applications including tissue repair and regeneration, wound healing, and 3D tissue/disease modeling.more » « less
-
Adhesive hydrogels with tunable mechanical properties and strong adhesion to wet, dynamic tissues have emerged as promising materials for tissue repair, with potential applications in wound closure, hemorrhage control, and surgical adhesives. This review highlights the key design principles, material classifications, and recent advances in adhesive hydrogels designed for vascular repair. The limitations of existing adhesive hydrogels, including insufficient mechanical durability, suboptimal biocompatibility, and challenges in targeted delivery, are critically evaluated. Furthermore, innovative strategies—such as incorporating self-healing capabilities, developing stimuli-responsive systems, integrating functional nanocomposites, and employing advanced fabrication techniques like 3D bioprinting—are discussed to enhance adhesion, mechanical stability, and vascular tissue regeneration. While significant progress has been made, further research and optimization are necessary to advance these materials toward clinical translation, offering a versatile and minimally invasive alternative to traditional vascular repair techniques.more » « less
-
The extracellular matrix (ECM) represents a complex and dynamic framework for cells, characterized by tissue-specific biophysical, mechanical, and biochemical properties. ECM components in vascular tissues provide structural support to vascular cells and modulate their function through interaction with specific cell-surface receptors. ECM–cell interactions, together with neurotransmitters, cytokines, hormones and mechanical forces imposed by blood flow, modulate the structural organization of the vascular wall. Changes in the ECM microenvironment, as in post-injury degradation or remodeling, lead to both altered tissue function and exacerbation of vascular pathologies. Regeneration and repair of the ECM are thus critical toward reinstating vascular homeostasis. The self-renewal and transdifferentiating potential of stem cells (SCs) into other cell lineages represents a potentially useful approach in regenerative medicine, and SC-based approaches hold great promise in the development of novel therapeutics toward ECM repair. Certain adult SCs, including mesenchymal stem cells (MSCs), possess a broader plasticity and differentiation potential, and thus represent a viable option for SC-based therapeutics. However, there are significant challenges to SC therapies including, but not limited to cell processing and scaleup, quality control, phenotypic integrity in a disease milieu in vivo , and inefficient delivery to the site of tissue injury. SC-derived or -inspired strategies as a putative surrogate for conventional cell therapy are thus gaining momentum. In this article, we review current knowledge on the patho-mechanistic roles of ECM components in common vascular disorders and the prospects of developing adult SC based/inspired therapies to modulate the vascular tissue environment and reinstate vessel homeostasis in these disorders.more » « less
-
Abstract Fibrosis occurs in many chronic diseases with lymphatic vascular insufficiency (e.g., kidney disease, tumors, and lymphedema). New lymphatic capillary growth can be triggered by fibrosis‐related tissue stiffening and soluble factors, but questions remain for how related biomechanical, biophysical, and biochemical cues affect lymphatic vascular growth and function. The current preclinical standard for studying lymphatics is animal modeling, but in vitro and in vivo outcomes often do not align. In vitro models can also be limited in their ability to separate vascular growth and function as individual outcomes, and fibrosis is not traditionally included in model design. Tissue engineering provides an opportunity to address in vitro limitations and mimic microenvironmental features that impact lymphatic vasculature. This review discusses fibrosis‐related lymphatic vascular growth and function in disease and the current state of in vitro lymphatic vascular models while highlighting relevant knowledge gaps. Additional insights into the future of in vitro lymphatic vascular models demonstrate how prioritizing fibrosis alongside lymphatics will help capture the complexity and dynamics of lymphatics in disease. Overall, this review aims to emphasize that an advanced understanding of lymphatics within a fibrotic disease—enabled through more accurate preclinical modeling—will significantly impact therapeutic development toward restoring lymphatic vessel growth and function in patients.more » « less
