Polyelectrolyte multilayer film and human mesenchymal stem cells: An attractive alternative in vascular engineering applications

Stressful Surfaces: Cell Metabolism on a Poorly Adhesive Substrate

The adhesion and proliferation of cells are exquisitely sensitive to the nature of the surface to which they attach. Aside from cell counting, cell "health" on surfaces is typically established by measuring the metabolic rate with dyes that participate in the metabolic pathway or using "live/dead" assays with combinations of membrane permeable/impermeable dyes. The binary information gleaned from these tests-whether cells are attached or not, and whether they are living or dead-provides an incomplete picture of cell health. In the present work, proliferation rates and net metabolism of 3T3 fibroblasts seeded on "biocompatible" ultrathin polyelectrolyte multilayer films and on control tissue culture plastic were compared. Cells adhered to, and proliferated on, both surfaces, which were shown to be nontoxic according to live/dead assays. However, adhesion was poorer on the multilayer surface, illustrated by diffuse organization of the actin cytoskeleton and less-developed focal adhesions. Proliferation was also slower on the multilayer. When normalized for the total number of cells, it was shown that cells on multilayers experienced a five-day burst of metabolic stress, after which the metabolic rate approached that of the control surface. This initial state of high stress has not been reported or appreciated in studies of cell growth on multilayers, although the observation period for this system is usually a few days.

Establishment and characterization of female reproductive tract epithelial cell culture

The oviductal and uterine epithelial cells have a crucial role, but are still poorly understood. Numerous studies have tried to isolate the epithelial cells from different organs in various models. The current study aimed to establish and characterize an in vitro monolayer culture of the oviduct and uterine horn epithelial cells by using two different techniques. Female reproductive epithelial cells from sows were cultured in follicular phase. Combined protocols to isolate the epithelial cells were performed. The viability and cell number were determined. Monolayers of epithelial cells from each group were cultured in four-well plates and were subjected to immunostaining using a Vector ABC Elite Kit. The immunohistochemical staining step was performed to evaluate the quality of the epithelial cells. Oviductal cells reached confluence faster than uterine horn cells. Cilia were seen in oviduct and uterine horn tissue culture. All the isolated cells reached confluence prior to harvesting. The number of cells was increased over the time of incubation. Monolayer culture using the trypsin/EDTA method took longer than culture with the collagenase method. Immunohistochemistry of epithelial cells showed strong staining for cytokeratin. Oviductal and uterus epithelial cells were cultured and established. Both techniques used in this experiment were useful and showed no significant differences. This cell culture model has the potential to study the secretory interactions of the female reproductive tract with spermatozoa, oocytesor embryos.

Scaffolds and Cell-Based Tissue Engineering for Blood Vessel Therapy

The increasing morbidity of cardiovascular diseases in modern society has made it crucial to develop a small-caliber blood vessel. In the absence of appropriate autologous vascular grafts, an alternative prosthesis must be constructed for cardiovascular disease patients. The aim of this article is to describe the advances in making cell-seeded cardiovascular prostheses. It also discusses the combinations of types of scaffolds and cells, especially autologous stem cells, which are suitable for application in tissue-engineered vessels with the favorable properties of mechanical strength, antithrombogenicity, biocompliance, anti-inflammation, fatigue resistance and long-term durability. This article highlights the advancements in cellular tissue-engineered vessels in recent years.

Cell-based strategies for vascular regeneration

Vascular regeneration is known to play an essential role in the repair of injured tissues mainly through accelerating the repair of vascular injury caused by vascular diseases, as well as the recovery of ischemic tissues. However, the clinical vascular regeneration is still challenging. Cell-based therapy is thought to be a promising strategy for vascular regeneration, since various cells have been identified to exert important influences on the process of vascular regeneration such as the enhanced endothelium formation on the surface of vascular grafts, and the induction of vessel-like network formation in the ischemic tissues. Here are a vast number of diverse cell-based strategies that have been extensively studied in vascular regeneration. These strategies can be further classified into three main categories, including cell transplantation, construction of tissue-engineered grafts, and surface modification of scaffolds. Cells used in these strategies mainly refer to terminally differentiated vascular cells, pluripotent stem cells, multipotent stem cells, and unipotent stem cells. The aim of this review is to summarize the reported research advances on the application of various cells for vascular regeneration, yielding insights into future clinical treatment for injured tissue/organ.

Polyelectrolyte multilayer film modification for chemo-mechano-regulation of endothelial cell response

The new multilayer polyelectrolyte films (PEMs) that are able to simulate the structure and functions of the extracellular matrix have become a powerful tool for tailoring biointerfaces of “cardiovascular” implants.

Application of Nanoscaffolds in Mesenchymal Stem Cell-Based Therapy

Regenerative medicine is an alternative solution for organ transplantation. Stem cells and nanoscaffolds are two essential components in regenerative medicine. Mesenchymal stem cells (MSCs) are considered as primary adult stem cells with high proliferation capacity, wide differentiation potential, and immunosuppression properties which make them unique for regenerative medicine and cell therapy. Scaffolds are engineered nanofibers that provide suitable microenvironment for cell signalling which has a great influence on cell proliferation, differentiation, and biology. Recently, application of scaffolds and MSCs is being utilized in obtaining more homogenous population of MSCs with higher cell proliferation rate and greater differentiation potential, which are crucial factors in regenerative medicine. In this review, the definition, biology, source, characterization, and isolation of MSCs and current report of application of nanofibers in regenerative medicine in different lesions are discussed.

Effect of lumican on the migration of human mesenchymal stem cells and endothelial progenitor cells: involvement of matrix metalloproteinase-14

Background

Increasing number of evidence shows that soluble factors and extracellular matrix (ECM) components provide an optimal microenvironment controlling human bone marrow mesenchymal stem cell (MSC) functions. Successful in vivo administration of stem cells lies in their ability to migrate through ECM barriers and to differentiate along tissue-specific lineages, including endothelium. Lumican, a protein of the small leucine-rich proteoglycan (SLRP) family, was shown to impede cell migration and angiogenesis. The aim of the present study was to analyze the role of lumican in the control of MSC migration and transition to functional endothelial progenitor cell (EPC).

Methodology/Principal Findings

Lumican inhibited tube-like structures formation on Matrigel® by MSC, but not EPC. Since matrix metalloproteinases (MMPs), in particular MMP-14, play an important role in remodelling of ECM and enhancing cell migration, their expression and activity were investigated in the cells grown on different ECM substrata. Lumican down-regulated the MMP-14 expression and activity in MSC, but not in EPC. Lumican inhibited MSC, but not EPC migration and invasion. The inhibition of MSC migration and invasion by lumican was reversed by MMP-14 overexpression.

Conclusion/Significance

Altogether, our results suggest that lumican inhibits MSC tube-like structure formation and migration via mechanisms that involve a decrease of MMP-14 expression and activity.

Vascular potency of Sus scrofa bone marrow-derived mesenchymal stem cells: a progenitor source of medial but not endothelial cells

Short-term thrombotic occlusion and compliance mismatch hamper clinical use of synthetic small-diameter tissue engineered vascular grafts. It is felt that preconditioning of the graft with intimal (endothelial) and medial (vascular smooth muscle) cells contributes to patency of the graft. Autologous, non-vessel-derived cells are preferred because of systemic vascular pathology and immunologic concerns. We tested in a porcine model whether cultured bone marrow-derived mononuclear cells, also referred to as mesenchymal stem cells (MSC), are a potential source of intimal or medial cells in vascular tissue engineering. We show that MSC cultured in endothelial medium do not gain an endothelial phenotype or functional characteristics, even after enrichment for CD31, culturing under flow, treatment with additional growth factors (vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF)-2), or co-culture with microvascular endothelial cells (EC). On the other hand, we show that MSC cultured in MSC medium, but not in smooth muscle cell medium, show phenotypical and functional characteristics of vascular smooth muscle cells. We conclude that bone marrow-derived MSCs can be used as a bona fide source of medial, but not EC in small-diameter vascular tissue engineering.