Tumor Treating Fields (TTFields) Concomitant with Immune Checkpoint Inhibitors Are Therapeutically Effective in Non-Small Cell Lung Cancer (NSCLC) In Vivo Model.

Tumor Treating Fields (TTFields) are electric fields that exert physical forces to disrupt cellular processes critical for cancer cell viability and tumor progression. TTFields induce anti-mitotic effects through the disruption of the mitotic spindle and abnormal chromosome segregation, which trigger several forms of cell death, including immunogenic cell death (ICD). The efficacy of TTFields concomitant with anti-programmed death-1 (anti-PD-1) treatment was previously shown in vivo and is currently under clinical investigation. Here, the potential of TTFields concomitant with anti- PD-1/anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA-4) or anti-programmed death-ligand 1 (anti-PD-L1) immune checkpoint inhibitors (ICI) to improve therapeutic efficacy was examined in lung tumor-bearing mice. Increased circulating levels of high mobility group box 1 protein (HMGB1) and elevated intratumoral levels of phosphorylated eukaryotic translation initiation factor 2α (p-eIF2α) were found in the TTFields-treated mice, indicative of ICD induction. The concomitant application of TTFields and ICI led to a significant decrease in tumor volume as compared to all other groups. In addition, significant increases in the number of tumor-infiltrating immune cells, specifically cytotoxic T-cells, were observed in the TTFields plus anti-PD-1/anti-CTLA-4 or anti-PD-L1 groups. Correspondingly, cytotoxic T-cells isolated from these tumors showed higher levels of IFN-γ production. Collectively, these results suggest that TTFields have an immunoactivating role that may be leveraged for concomitant treatment with ICI to achieve better tumor control by enhancing antitumor immunity.

The Modulatory Effect of Adipose-Derived Stem Cells on Endometrial Polyp Fibroblasts.

Endometrial polyps (EPs) are benign overgrowths of the endometrium, with the potential to cause severe complications, ranging from discomfort to inflammation and infertility. Dysfunction of endometrial fibroblasts may be a critical component leading to the development of polyps. Although surgical intervention is the common remedy for severe cases, it comes with drawbacks, including infection, bleeding, and risk of damage to the cervix and adjacent tissues. Adipose-derived mesenchymal stromal cells (ASCs) are at the focus of modern medicine, as key modulators of tissue homeostasis, inflammation, and tissue repair, rendering them prime candidate agents for tissue regeneration and cell-based therapies. In this study, EPs were isolated from patients admitted to the OB/GYN department at the Galilee Medical Center and extracted fibroblasts (endometrial polyp fibroblasts, EPFs) were isolated and characterized. ASCs were isolated from healthy patients. The effect of EPF- and ASC-conditioned media (CM) on polyp-derived fibroblasts was evaluated, in both 2D and 3D assays, as well as on the expression of matrix-related gene expression. Herein, EPFs exposed to ASC-CM exhibited reduced migration, invasion, contraction of hydrogels, and extracellular matrix deposition, compared with those exposed to EPF-CM. Altogether, this study suggests that ASCs may have a modulating effect on fibroblasts involved in forming EPs and may serve as the basis for conservative treatment strategies aimed at treating severe cases of EPs.

COVID-19 Vaccine Acceptance Among Dental Professionals Based on Employment Status During the Pandemic.

The COVID-19 pandemic spread rapidly across the globe, leading governments to impose prolonged lockdowns on both movement and commerce. Although lockdowns decrease the rates of novel infections, they can have devastating consequences on the economy and employment levels. One of the most severely affected sectors during this crisis has been dental medicine. Dental professionals are uniquely exposed to environments with high levels of occupational hazards, conferring additional risks of viral exposure and transmission. We analyzed 506 anonymous questionnaires completed by dentists and residents regarding acceptance of a future potential SARS-CoV-2 vaccine. Our results demonstrate a statistically significant correlation between the individual's unemployment rate and their willingness to inoculate with a SARS-CoV-2 vaccine when it becomes available. This information can be used to predict trends of vaccine acceptance or rejection based on economic burden during the COVID-19 pandemic by different sectors as part of the preparedness toward global vaccination programs.

A Multichamber Gas System to Examine the Effect of Multiple Oxygen Conditions on Cell Culture.

The classic bone tissue engineering model for bone regeneration combines three elements: scaffolds, biomaterials, and mesenchymal stem cells (MSCs). Incorporation of MSCs and growth factors into a scaffold implanted into the area of bone injury is a proven strategy to achieve successful bone regeneration as demonstrated in the literature. However, a major limitation of using bone grafts or scaffolds is oxygen (O2) deprivation in the inner sections of the construct, due to lack of adequate vascularization. To address this limitation, we proposed two treatment strategies for MSC-seeded constructs or adipose tissue scaffolds before implantation: (1) O2 enrichment and (2) acclimation to hypoxia. Based on previous studies, the significance of the different O2 concentrations on MSC biological characteristics remains controversial. Therefore, the optimal O2 condition for engineered bone tissues should be determined. Thus, we designed an innovative multichamber gas system aimed to simultaneously assess the effects of different O2 levels on cell culture. This system was assembled using three isolated chambers integrated into a single incubator. To explore the efficacy of our method, we investigated the effect of hyperoxia, normoxia, and hypoxia, (50-60%, 21%, and 5-7.5% O2, respectively) on the biological characteristics of human adipose-derived MSCs: immunophenotyping, adhesion, proliferation, and osteogenic, and angiogenic differentiation. Our findings demonstrated that hypoxic adipose-derived mesenchymal stem cells (ASCs) conditions exhibited significantly lower levels of CD34 (p = 0.014), with significantly higher osteogenic and angiogenic differentiation capacities (p = 0.023 and p = 0.0042, respectively) than normoxia. Conversely, hyperoxia-cultured ASCs demonstrated significantly higher levels of CD73 and CD90 expression than both normoxic ASCs (p = 0.006 and p = 0.025, respectively) and hypoxic ASCs (p = 0.003 and p = 0.003, respectively). In addition, hyperoxic ASCs showed significantly reduced proliferation capacity by day 11 (p = 0.032) and significantly enhanced migration rates after 48 h (p = 0.044). The newly developed controllable multichamber gas system was cost-effective and easy to use. Different assays can be performed concurrently while preserving all other conditions identical, and the use of other ranges of O2 concentrations is feasible and also necessary to determine the ideal O2 concentration. Furthermore, the multichamber gas system has the potential for wide application, including other cell cultures, grafts, or scaffolds for in vitro and in vivo experimentation. This study was approved by the Galilee Medical Center Helsinki Committee (No. 0009-19-NHR). Impact statement The introduced multichamber gas system provides a custom-made setup for simultaneous control of three oxygen (O2) levels in a single incubator. The use of our innovative multichamber gas system is essential to determine the ideal O2 levels for engineered tissues by examining multiple O2 concentrations on cells in vitro. The determined ideal O2 concentration will then be used through this system to investigate the engrafted cell survival ex vivo, to ensure successful integration of the engineered tissues and tissue regeneration in vivo. Use of this method may promote a therapeutic tool for a major limitation in tissue engineering due to the problematic O2 insufficiency in tissue scaffolds.

An ECM-Mimicking, Mesenchymal Stem Cell-Embedded Hybrid Scaffold for Bone Regeneration.

While biologically feasible, bone repair is often inadequate, particularly in cases of large defects. The search for effective bone regeneration strategies has led to the emergence of bone tissue engineering (TE) techniques. When integrating electrospinning techniques, scaffolds featuring randomly oriented or aligned fibers, characteristic of the extracellular matrix (ECM), can be fabricated. In parallel, mesenchymal stem cells (MSCs), which are capable of both self-renewing and differentiating into numerous tissue types, have been suggested to be a suitable option for cell-based tissue engineering therapies. This work aimed to create a novel biocompatible hybrid scaffold composed of electrospun polymeric nanofibers combined with osteoconductive ceramics, loaded with human MSCs, to yield a tissue-like construct to promote in vivo bone formation. Characterization of the cell-embedded scaffolds demonstrated their resemblance to bone tissue extracellular matrix, on both micro- and nanoscales and MSC viability and integration within the electrospun nanofibers. Subcutaneous implantation of the cell-embedded scaffolds in the dorsal side of mice led to new bone, muscle, adipose, and connective tissue formation within 8 weeks. This hybrid scaffold may represent a step forward in the pursuit of advanced bone tissue engineering scaffolds.