Recent Developments in Biomaterial-Based Hydrogel as the Delivery System for Repairing Endometrial Injury

Hydrogels, due to their unique biocompatibility, flexible methods of synthesis, range of constituents, and desirable physical characteristics, have been the material of choice for many applications in regenerative medicine. They can serve as scaffolds that provide structural integrity to tissue constructs, control drug and protein delivery to tissues and cultures, and serve as adhesives or barriers between tissue and material surfaces. In this work, the properties of hydrogels that are important for tissue engineering applications and the inherent material design constraints and challenges are discussed. Recent research involving several different hydrogels polymerized from a variety of synthetic and natural monomers using typical and novel synthetic methods are highlighted. Finally, special attention is given to the microfabrication techniques that are currently resulting in important advances in the field. Show more

Mesenchymal stem cell transplantation is undergoing extensive evaluation as a cellular therapy in human clinical trials. Because MSCs are easily isolated and amenable to culture expansion in vitro there is a natural desire to test MSCs in many diverse clinical indications. This is exemplified by the rapidly expanding literature base that includes many in vivo animal models. More recently, MSC-derived extracellular vesicles (EVs), which include exosomes and microvesicles (MV), are being examined for their role in MSC-based cellular therapy. These vesicles are involved in cell-to-cell communication, cell signaling, and altering cell or tissue metabolism at short or long distances in the body. The exosomes and MVs can influence tissue responses to injury, infection, and disease. MSC-derived exosomes have a content that includes cytokines and growth factors, signaling lipids, mRNAs, and regulatory miRNAs. To the extent that MSC exosomes can be used for cell-free regenerative medicine, much will depend on the quality, reproducibility, and potency of their production, in the same manner that these parameters dictate the development of cell-based MSC therapies. However, the MSC exosome's contents are not static, but rather a product of the MSC tissue origin, its activities and the immediate intercellular neighbors of the MSCs. As such, the exosome content produced by MSCs appears to be altered when MSCs are cultured with tumor cells or in the in vivo tumor microenvironment. Therefore, careful attention to detail in producing MSC exosomes may provide a new therapeutic paradigm for cell-free MSC-based therapies with decreased risk. Stem Cells 2017;35:851-858. Show more