skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Protocols for Full Thickness Skin Wound Repair Using Prevascularized Human Mesenchymal Stem Cell Sheet
Split thickness skin grafts (STSGs) are one of the standard treatments available for full thickness wound repair when full thickness grafts (FTGs) are not viable, such as in the case of wounds with large surface areas. The donor sites of STSGs may be harvested repeatedly, but STSG transplants are still limited by insufficient blood supply at the early stages of wound healing. Prevascularized human mesenchymal stem cell (hMSC) sheets may accelerate wound healing and improve regeneration by providing pre-formed vessel structures and angiogenic factors to overcome this limitation. This book chapter provides the protocol of co-culturing hMSCs and endothelial cells to attain a prevascularized hMSC cell sheet (PHCS). The protocols for implantation of the prevascularized stem cell sheet for full thickness skin wound repair in a rat autologous skin graft model as well as the evaluation of the wound healing effects are also provided.  more » « less
Award ID(s):
1703570
PAR ID:
10060499
Author(s) / Creator(s):
Date Published:
Journal Name:
Methods in molecular biology
ISSN:
1064-3745
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Wound healing presents a unique challenge for patients with diabetes. Gas therapies have gained significant attention in the wound-healing community. Carbon monoxide (CO) is a small molecule that is well known for its immune-modulating properties when administered at sublethal concentrations. CO is currently in clinical trials for lung disease, sickle cell anemia, and organ transplantation. Here, we investigated the effects of CO in an in vitro wound-healing model and subsequently developed and tested CO gas-entrapping materials (CO-GEMs) for topical application on wounds to promote healing. In this study, we report the efficacy of CO-GEMs in treating full-thickness wounds and pressure ulcers in diabetic mouse models. Collectively, our findings demonstrate that these novel gas entrapping materials could serve as an alternative therapy to both protect the wound bed and promote healing and replace bulky hyperbaric chambers, standard gauze wound dressings, or expensive skin grafts. 
    more » « less
  2. null (Ed.)
    A number of challenges in skin grafting for wound healing have drawn researchers to focus on skin tissue engineering as an alternative solution. The core idea of tissue engineering is to use scaffolds, cells, and/or bioactive molecules to help the skin to properly recover from injuries. Over the past decades, the field has significantly evolved, developing various strategies to accelerate and improve skin regeneration. However, there are still several concerns that should be addressed. Among these limitations, vascularization is known as a critical challenge that needs thorough consideration. Delayed wound healing of large defects results in an insufficient vascular network and ultimately ischemia. Recent advances in the field of tissue engineering paved the way to improve vascularization of skin substitutes. Broadly, these solutions can be classified into two categories as (1) use of growth factors, reactive oxygen species-inducing nanoparticles, and stem cells to promote angiogenesis, and (2) in vitro or in vivo prevascularization of skin grafts. This review summarizes the state-of-the-art approaches, their limitations, and highlights the latest advances in therapeutic vascularization strategies for skin tissue engineering. 
    more » « less
  3. Zwitterionic hydrogels, as highly hydrated and soft materials, have been considered as promising materials for wound dressing, due to their unique antifouling and mechanical properties. While the viscoelasticity and softness of zwitterionic hydrogels are hypothetically essential for creating adaptive cellular niches, the underlying mechanically regulated wound healing mechanism still remains elusive. To test this hypothesis, we fabricated zwitterionic poly(sulfobetaine methacrylate) (polySBMA) hydrogels with different elastic moduli prepared at different crosslinker contents, and then applied the hydrogels to full-thickness cutaneous wounds in mice. In vivo wound healing studies compared the mechanical cue-induced effects of soft and stiff polySBMA hydrogels on wound closure rates, granulation tissue formation and collagen deposition. Collective results showed that the softer and more viscoelastic hydrogels facilitated cell proliferation, granulation formation, collagen aggregation, and chondrogenic ECM deposition. Such high wound healing efficiency by the softer hydrogels is likely attributed to stress dissipation by expanding the cell proliferation, the up-regulation of blood vessel formation, and the enhanced polarization of M2/M1 macrophages, both of which would provide more oxygen and nutrients for cell proliferation and migration, leading to enhanced wound repair. This work not only reveals a mechanical property–wound healing relationship of zwitterionic polySBMA hydrogels, but also provides a promising candidate and strategy for the next-generation of wound dressings. 
    more » « less
  4. Abstract Preparation of human mesenchymal stem cell (hMSC) suspension for lymphedema treatment relies on conventional enzymatic digestion methods, which severely disrupts cell–cell and cell–extracellular matrix (ECM) connections, and drastically impairs cell retention and engraftment after transplantation. The objective of the present study is to evaluate the ability of hMSC‐secreted ECM to augment lymphangiogenesis by using an in vitro coculturing model of hMSC sheets with lymphatic endothelial cells (LECs) and an in vivo mouse tail lymphedema model. Results demonstrate that the hMSC‐secreted ECM augments the formation of lymphatic capillary‐like structure by a factor of 1.2–3.6 relative to the hMSC control group, by serving as a prolymphangiogenic growth factor reservoir and facilitating cell regenerative activities. hMSC‐derived ECM enhances MMP‐2 mediated matrix remodeling, increases the synthesis of collagen IV and laminin, and promotes lymphatic microvessel‐like structure formation. The injection of rat MSC sheet fragments into a mouse tail lymphedema model confirms the benefits of the hMSC‐derived ECM by stimulating lymphangiogenesis and wound closure. 
    more » « less
  5. Human mesenchymal stem cells (hMSCs) are instrumental in the wound healing process. They migrate to wounds from their native niche in response to chemical signals released during the inflammatory phase of healing. At the wound, hMSCs downregulate inflammation and regulate tissue regeneration. Delivering additional hMSCs to wounds using cell-laden implantable hydrogels has the potential to improve healing outcomes and restart healing in chronic wounds. For these materials to be effective, cells must migrate from the scaffold into the native tissue. This requires cells to traverse a step-change in material properties at the implant-tissue interface. Migration of cells in material with highly varying properties is not well characterized. We measure 3D encapsulated hMSC migration and remodeling in a well-characterized hydrogel with a step-change in stiffness. This cell-degradable hydrogel is composed of 4-arm poly(ethylene glycol)-norbornene cross-linked with an enzymatically-degradable peptide. The scaffold is made with two halves of different stiffnesses separated by an interface where stiffness changes rapidly. We characterize changes in structure and rheology of the pericellular region using multiple particle tracking microrheology (MPT). MPT measures Brownian motion of embedded particles and relates it to material rheology. We measure more remodeling in the soft region of the hydrogel than the stiff region on day 1 post-encapsulation and similar remodeling everywhere on day 6. In the interface region, we measure hMSC-mediated remodeling along the interface and migration towards the stiff side of the scaffold. These results can improve materials designed for cell delivery from implants to a wound to enhance healing. 
    more » « less