Infusion of Some but Not All Types of Human Perinatal Stromal Cells Prevent Organ Fibrosis in a Humanized Graft versus Host Disease Murine Model.

Allogeneic transplant rejection represents a medical complication that leads to high morbidity and mortality rates. There are no treatments to effectively prevent fibrosis; however, there is great interest in evaluating the use of perinatal mesenchymal stromal cells (MSCs) and other MSCs to prevent fibrosis associated with chronic rejection. In this study, we isolated human perinatal stromal cells (PSCs) from amnion (AM-PSC), placental villi (PV-PSC), and umbilical cord (UC-PSC) tissues, demonstrating the phenotypic characteristics of MSCs as well as a >70% expression of the immunomodulatory markers CD273 and CD210. The administration of a single dose (250,000 cells) of each type of PSC in a humanized graft versus host disease (hGvHD) NSG® murine model delayed the progression of the disease as displayed by weight loss and GvHD scores ranging at various levels without affecting the hCD3+ population. However, only PV-PSCs demonstrated an increased survival rate of 50% at the end of the study. Furthermore, a histopathological evaluation showed that only PV-PSC cells could reduce human CD45+ cell infiltration and the fibrosis of the lungs and liver. These findings indicate that not all PSCs have similar therapeutic potential, and that PV-PSC as a cell therapeutic may have an advantage for targeting fibrosis related to allograft rejection.

Umbilical cord plasma concentrate has beneficial effects on DNA methylation GrimAge and human clinical biomarkers.

Plasma transfusions are standard treatments to replace missing proteins in people with rare genetic diseases. Prior studies have demonstrated that heterochronic parabiosis has beneficial effects on several tissues of old animals receiving young blood. Human clinical trials are currently underway to investigate whether the infusion of plasma or plasma-derived factors from young donors can be used to mitigate human age-related conditions. Here, we use data from a safety study (n = 18, mean age 74) to investigate whether human umbilical cord plasma concentrate (hereinafter Plasma Concentrate) injected weekly (1 ml intramuscular) into elderly human subjects over a 10-week period affects different biomarkers, including epigenetic age measures, standard clinical biomarkers of organ dysfunction, mitochondrial DNA copy number (mtDNA-CN), and leukocyte telomere length. This study shows that treatment with plasma concentrate is safe. More than 20 clinical biomarkers were significantly and beneficially altered following the treatments. For example, creatinine was significantly decreased (p = 0.0039), while estimated glomerular filtration rate (eGFR) was increased (p = 0.0044), indicating the treatment may improve biomarkers of kidney function. Three of four immunoglobulin biomarkers decreased, while telomere length and mtDNA-CN were not significantly affected by the treatment. The treatment reduced DNA methylation-based GrimAge by an average of 0.82 years (p = 0.0093), suggests a reduction in morbidity and mortality risk. By contrast, no significant results could be observed for epigenetic clocks that estimate chronological age. Our results support the view that plasma concentrate contains youth-promoting factors.

PEGylated Platelet-Free Blood Plasma-Based Hydrogels for Full-Thickness Wound Regeneration.

Objective: To develop a cost-effective and clinically usable therapy to treat full-thickness skin injuries. We accomplished this by preparing a viscoelastic hydrogel using polyethylene glycol (PEG)-modified platelet-free plasma (PEGylated PFP) combined with human adipose-derived stem cells (ASCs). Approach: PEGylated PFP hydrogels were prepared by polymerizing the liquid mixture of PEG and PFP±ASCs and gelled either by adding calcium chloride (CaCl2) or thrombin. Rheological and in vitro studies were performed to assess viscoelasticity and the ability of hydrogels to direct ASCs toward a vasculogenic phenotype, respectively. Finally, a pilot study evaluated the efficacy of hydrogels±ASCs using an athymic rat full-thickness skin wound model. Results: Hydrogels prepared within the range of 11 to 27 mM for CaCl2 or 5 to 12.5 U/mL for thrombin exhibited a storage modulus of ∼62 to 87 Pa and ∼47 to 92 Pa, respectively. The PEGylated PFP hydrogels directed ASCs to form network-like structures resembling vasculature, with a fourfold increase in perivascular specific genes that were confirmed by immunofluorescent staining. Hydrogels combined with ASCs exhibited an increase in blood vessel density when applied to excisional rat wounds compared with those treated with hydrogels (110.3 vs. 95.6 BV/mm2; p < 0.05). Furthermore, ASCs were identified in the perivascular region associated with newly forming blood vessels. Innovation: This study demonstrates that PFP modified with PEG along with ASCs can be used to prepare cost-effective stable hydrogels, at the bed-side, to treat extensive skin wounds. Conclusion: These results indicate that PEGylated plasma-based hydrogels combined with ASCs may be a potential regenerative therapy for full-thickness skin wounds.

Hepatocyte-like cells derived from human amniotic epithelial, bone marrow, and adipose stromal cells display enhanced functionality when cultured on decellularized liver substrate.

Transplantation of primary hepatocytes has been used in treatments for various liver pathologies and end-stage liver disease. However, shortage of donor tissue and the inability of hepatocyte proliferation in vitro have lead to alternative methods such as stem cell-derived hepatocyte-like cells (HLCs). Mesenchymal stromal/stem cells, and amniotic epithelial cells were isolated from human bone marrow (BM-MSCs), lipoaspirates (ASCs), and amniotic tissue (AECs) respectively. All cells were differentiated into HLCs on plates coated with Type I collagen or Porcine Liver Extracellular Matrix (PLECM-AA) matrix. Flow cytometry of BM-MSCs and ASCs, and AECs showed high expression of MSC-specific and embryonic stem cell markers respectively. All cell types differentiated into osteocytes, chondrocytes, and adipocytes. All cell type-derived HLCs presented the typical cuboidal primary hepatocyte morphology on PLECM-AA and fewer vacuoles (AECs) compared to HLCs cultured on type I collagen. Gene analysis of all cell type-derived HLCs cultured on PLECM-AA revealed higher upregulation of genes involved in drug transportation and metabolism compared to HLCs cultured on type I collagen. Although, HLCs cultured on PLECM-AA displayed some hepatocyte-related function and bioactivity, overall gene expression was lower compared to that of primary hepatocytes suggesting that caution should be taken when considering using HLCs to replace total hepatocyte functionality.

Decellularization and Solubilization of Porcine Liver for Use as a Substrate for Porcine Hepatocyte Culture: Method Optimization and Comparison.

Biologic substrates, prepared by decellularizing and solubilizing tissues, have been of great interest in the tissue engineering field because of the preservation of complex biochemical constituents found in the native extracellular matrix (ECM). The integrity of the ECM is critical for cell behavior, adhesion, migration, differentiation, and proliferation that in turn affect homeostasis and tissue regeneration. Previous studies have shown that various processing methods have a distinctive way of affecting the composition of the decellularized ECM. In this study, we developed a bioactive substrate for hepatocytes in vitro, made of decellularized and solubilized liver tissue. The present work is a comparative approach of 2 different methods. First, we decellularized porcine liver tissue with ammonium hydroxide versus a sodium deoxycholate method, then characterized the decellularized tissue using various methods including double stranded DNA (dsDNA) content, DNA size, immunogenicity, and mass spectrometry. Second, we solubilized the decellularized porcine liver with hydrochloric acid versus acetic acid (AA) and characterized the resultant solubilized tissues using relevant methodologies including protein yield, immunogenicity, and bioactivity. Finally, we isolated primary porcine hepatocytes, cultured, and evaluated their bioactivity on the optimized decellularized-solubilized liver substrate. The decellularized porcine liver ECM processed by the ammonium hydroxide method and solubilized with AA displayed higher ECM integrity, low dsDNA, no evidence of intact nuclei, low human monocyte chemoattraction, and the presence of key molecules typically found in the native liver, a very important element for normal cell function. In addition, primary porcine hepatocytes showed enhanced functionality including albumin and urea production and bile canaliculi formation when cultured on the developed liver substrate compared to type I collagen.

Adsorption of Proteins to Thin-Films of PDMS and Its Effect on the Adhesion of Human Endothelial Cells.

This paper describes a simple and inexpensive procedure to produce thin-films of poly(dimethylsiloxane). Such films were characterized by a variety of techniques (ellipsometry, nuclear magnetic resonance, atomic force microscopy, and goniometry) and used to investigate the adsorption kinetics of three model proteins (fibrinogen, collagen type-I, and bovine serum albumin) under different conditions. The information collected from the protein adsorption studies was then used to investigate the adhesion of human dermal microvascular endothelial cells. The results of these studies suggest that these films can be used to model the surface properties of microdevices fabricated with commercial PDMS. Moreover, the paper provides guidelines to efficiently attach cells in BioMEMS devices.