Oxaloacetate as new inducer for osteogenic differentiation of human adipose tissue-derived mesenchymal stem cells in vitro.

BACKGROUND: Mitochondrial organelles play a crucial role in cellular metabolism so different cell types exhibit diverse metabolic and energy demands. Therefore, alternations in the intracellular distribution, quantity, function, and structure of mitochondria are required for stem cell differentiation. Finding an effective inducer capable of modulating mitochondrial activity is critical for the differentiation of specific stem cells into osteo-like cells for addressing issues related to osteogenic disorders. This study aimed to investigate the effect of oxaloacetate (OAA) on the osteogenic differentiation of human adipose-derived mesenchymal stem cells (hADSCs) in vitro. METHODS AND RESULTS: First, the most favorable OAA concentration was measured through MTT assay and subsequently confirmed using acridine orange staining. Human ADSCs were cultured in osteogenic medium supplemented with OAA and analyzed on days 7 and 14 of differentiation. Various assays including alkaline phosphatase assay (ALP), cellular calcium content assay, mineralized matrix staining with alizarin red, catalase (CAT) and superoxide dismutase (SOD) activity, and real-time RT-PCR analysis of three bone-specific markers (ALP, osteocalcin, and collagen type I) were conducted to characterize the differentiated cells. Following viability assessment, OAA at a concentration of 1 µM was considered the optimal dosage for further studies. The results of osteogenic differentiation assays showed that OAA at a concentration of 1 × 10- 6 M significantly increased ALP enzyme activity, mineralization, CAT and SOD activity and the expression of bone-specific genes in differentiated cells compared to control groups in vitro. CONCLUSIONS: In conclusion, the fundings from this study suggest that OAA possesses favorable properties that make it a potential candidate for application in medical bone regeneration.

Mesenchymal stem cells osteogenic differentiation by ZnO nanoparticles and polyurethane bimodal foam nanocomposites.

Mesenchymal stem cells with tissue repair capacity involve in regenerative medicine. MSCs can promote bone repair when employed with nano scaffolds/particles. Here, the MTT and Acridine Orange assay enabled the cytotoxic concentration of Zinc oxide nanoparticles and Polyurethane evaluation. Following culturing adipose tissue-derived MSCs, ADSCs' proliferation, growth, and osteogenic differentiation in the presence of PU with and without ZnO NPs is tracked by a series of biological assays, including Alkaline Phosphatase activity, Calcium deposition, alizarin red staining, RT-PCR, scanning electron microscope, and immunohistochemistry. The results showed boosted osteogenic differentiation of ADSCs in the presence of 1% PU scaffold and ZnO NPS and can thus apply as a new bone tissue engineering matrix. The expression level of Osteonectin, Osteocalcin, and Col1 increased in PU-ZnO 1% on the 7th and 14th days. There was an increase in the Runx2 gene expression on the 7th day of differentiation in PU-ZnO 1%, while it decreased on day 14th. In conclusion, Polyurethane nano scaffolds supported the MSCs' growth and rapid osteogenic differentiation. The PU-ZnO helps not only with cellular adhesion and proliferation but also with osteogenic differentiation.

Activated mesenchymal stem cells increase drug susceptibility of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa.

Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa are major causes of hospital-acquired infections and sepsis. Due to increasing antibiotic resistance, new treatments are needed. Mesenchymal stem cells (MSCs) have antimicrobial effects, which can be enhanced by preconditioning with antibiotics. This study investigated using antibiotics to strengthen MSCs against MRSA and P. aeruginosa. MSCs were preconditioned with linezolid, vancomycin, meropenem, or cephalosporin. Optimal antibiotic concentrations were determined by assessing MSC survival. Antimicrobial effects were measured by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antimicrobial peptide (AMP) gene expression. Optimal antibiotic concentrations for preconditioning MSCs without reducing viability were 1 µg/mL for linezolid, meropenem, and cephalosporin and 2 µg/mL for vancomycin. In MIC assays, MSCs preconditioned with linezolid, vancomycin, meropenem, or cephalosporin inhibited MRSA or P. aeruginosa growth at lower concentrations than non-preconditioned MSCs (p ≤ 0.001). In MBC assays, preconditioned MSCs showed enhanced bacterial clearance compared to non-preconditioned MSCs, especially when linezolid and vancomycin were used against MRSA (p ≤ 0.05). Preconditioned MSCs showed increased expression of genes encoding the antimicrobial peptide genes hepcidin and LL-37 compared to non-preconditioned MSCs. The highest hepcidin expression was seen with linezolid and vancomycin preconditioning (p ≤ 0.001). The highest LL-37 expression was with linezolid preconditioning (p ≤ 0.001). MSCs' preconditioning with linezolid, vancomycin, meropenem, or cephalosporin at optimal concentrations enhances their antimicrobial effects against MRSA and P. aeruginosa without compromising viability. This suggests preconditioned MSCs could be an effective adjuvant treatment for antibiotic-resistant infections. The mechanism may involve upregulation of AMP genes.

VZV Encephalitis with Brucella coinfection-case report.

Encephalitis occasionally occurs due to the central nervous system (CNS) infection by Varicella-zoster virus (VZV). The coincidence of herpes Encephalitis-brain infection and brucellosis occurs rarely. In this case, a 56-year-old woman was described with low consciousness, seizures, fever, and mood disorders. The brain CT revealed no pathological lesions, but MR showed non-specific plaques in the periventricular white matter. VZV was detected in molecular tests for the panel of viral Encephalitis in cerebrospinal fluid (CSF). The blood culture and the Wright test revealed the presence of Brucella spp. The antiviral treatment of choice was Acyclovir, Levetiracetam to control seizures, and Ampicillin/Sulbactam as prophylaxis antibiotics. Coinfections common poor prognoses makes it crucial to administer antiviral medications immediately. Many clinical challenges require a multidisciplinary team, including involvement of the CNS, resistance to viral strains, reactivation of diseases, and drug toxicity. The early detection of Encephalitis and treatment can promptly prevent exacerbation and complications.

Staphylococcal enterotoxin B as DNA vaccine against breast cancer in a murine model / Enterotoxina B estafilocócica como vacuna de ADN contra el cáncer de mama en un modelo murino

Recently, many efforts have been made to treat cancer using recombinant bacterial toxins and this strategy has been used in clinical trials of various cancers. Therapeutic DNA cancer vaccines are now considered as a promising strategy to activate the immune system against cancer. Cancer vaccines could induce specific and long-lasting immune responses against tumors. This study aimed to evaluate the antitumor potency of the SEB DNA vaccine as a new antitumor candidate against breast tumors in vivo. To determine the effect of the SEB construct on inhibiting tumor cell growth in vivo, the synthetic SEB gene, subsequent codon optimization, and embedding the cleavage sites were sub-cloned to an expression vector. Then, SEB construct, SEB, and PBS were injected into the mice. After being vaccinated, 4T1 cancer cells were injected subcutaneously into the right flank of mice. Then, the cytokine levels of IL-4 and IFN-γ were estimated by the ELISA method to evaluate the antitumor activity. The spleen lymphocyte proliferation, tumor size, and survival time were assessed. The concentration of IFN-γ in the SEB-Vac group showed a significant increase compared to other groups. The production of IL-4 in the group that received the DNA vaccine did not change significantly compared to the control group. The lymphocyte proliferation increased significantly in the mice group that received SEB construct than PBS control group (p < 0.001). While there was a meaningful decrease in tumor size (p < 0.001), a significant increase in tumor tissue necrosis (p < 0.01) and also in survival time of the animal model receiving the recombinant construct was observed.(AU)

A biomimetic multi-layer scaffold with collagen and zinc doped bioglass as a skin-regeneration agent in full-thickness injuries and its effects in vitro and in vivo.

Due to the multilayer structure of skin tissue, the fabrication of a 3-layer scaffold could result in planned dermal regeneration. Herein, polyurethane (PU) and polycaprolactone (PCL), as a function of their mechanical stability and collagen due to its arginine-glycine-aspartic acid sequences, zinc ions because of overcoming the common problems of biological factors were employed. The scaffolds' physical, mechanical, and biological properties were examined by SEM, FTIR, contact angle, mechanical tensile, bacteriocidal efficacy, and hemolysis. Also, after L-929 fibroblast seeding, their biological activity was determined by SEM, DAPI, and MTT assays. Then, the cell-seeded scaffolds were implanted in full-thickness wounds of rats and evaluated by wound closure, histological, and molecular techniques. The in vivo studies showed better wound closure with the composite scaffold containing zinc ions. While its dermal re-organization was retarded in the presence of zinc ions compared to the composite scaffold containing non-doped bioglass. Despite this, the doped composite scaffold indicated better observations with the histological evaluations than the nontreated and bare scaffold groups. Real-time PCR confirmed the higher expression of FGF2 and FGFR genes in rats treated with the zinc-doped composite scaffold. In conclusion, PU/PCL-collagen/PCL-collagen containing the doped or non-doped nanoparticles showed better potential to heal dermal injuries.

Schizophyllan promotes osteogenic differentiation of human adipose tissue-derived mesenchymal stem cells in vitro.

BACKGROUND: Bioactive polysaccharides are a promising way for bone disease prevention with high efficiency. Schizophyllan (SPG) is a polysaccharide derived from a species of fungus with anticancer, antitumor, and anti-inflammatory effects. In the present study, for the first time, the cell proliferation, osteogenic markers, mineral deposition, and osteogenic gene expression of human adipose tissue-derived mesenchymal stem cells (hADMSCs) grown on SPG were evaluated by in vitro assays. METHODS AND RESULTS: The cytotoxicity of SPG was measured using the MTT assay and acridine orange staining. Differentiation of hADMSCs was assessed using alkaline phosphatase (ALP) activity test, cellular calcium content assay, and mineralized matrix staining. To this end, Alizarin red S, von Kossa staining, and the expression of bone-specific markers, including ALP, Runx2, and osteonectin, were used by real-time RT-PCR over a 2-week period. According to the results, SPG at 10 µg/ml concentration was determined as the optimal dosage for differentiation studies. The results of osteogenic differentiation tests showed that compared to the control groups in vitro, SPG enhanced the osteogenic markers and mineralization as well as upregulation of the expression of bone specific genes in differentiated hADMSCs during differentiation. CONCLUSIONS: The results revealed that SPG could be applied as effective factor for osteogenic differentiation in the future. The current study provides insights into the hADMSC-based treatment and introduces promising therapeutic material for individuals who suffer from bone defects and injuries.

Apoptotic effects of mesenchymal stem cells' conditioned medium on colorectal cancer cell lines.

Multipotent Mesenchymal stem cells (MSCs) have vigorous immunomodulatory activity, apoptotic effects, and the capacity to migrate to inflammatory and tumor sites. This study focuses on the apoptotic effects of MSCs conditioned medium (CM) on colorectal cancer cell lines. MSCs were preconditioned with lipopolysaccharide (LPS) to induce apoptosis in colorectal cancer cells. The conditioned medium (LPS-CM) from the preconditioned cells was isolated and used to treat colorectal cancer cells (HT29 and SW48). The survival and proliferation of cancer cells were assessed using Trypan blue staining and MTT assay. The apoptosis rate was evaluated through flow cytometry analysis and caspase-3 activity. Additionally, Real-Time PCR was used to measure the mRNA level of apoptotic and anti-apoptotic factors, including bcl2, bax, and p53 genes. The results showed that LPS-CM significantly increased (p < 0.001) the percentage of apoptosis in the SW48 and HT29 cell lines. Caspase-3 activity significantly increased (p < 0.001) in these cell lines after treatment with LPS-CM. The mRNA level of bcl2 was significantly decreased (p < 0.001), while bax and p53 genes were significantly overexpressed (p < 0.001) in the LPS-CM treated cell lines. Notably, the mRNA level of bcl2 and bax genes was significantly altered at a higher concentration of LPS-CM. In conclusion, the conditioned medium from LPS-preconditioned MSCs can effectively induce apoptosis in colorectal cancer cells. This finding suggests that LPS-CM could be a potential strategy for inhibiting the proliferation and progression of colorectal cancer cells.

Monitoring saliva compositions for non-invasive detection of diabetes using a colorimetric-based multiple sensor.

The increasing population of diabetic patients, especially in developing countries, has posed a serious risk to the health sector, so that the lack of timely diagnosis and treatment process of diabetes can lead to threatening complications for the human lifestyle. Here, a multiple sensor was fabricated on a paper substrate for rapid detection and controlling the progress of the diabetes disease. The proposed sensor utilized the sensing ability of porphyrazines, pH-sensitive dyes and silver nanoparticles in order to detect the differences in saliva composition of diabetic and non-diabetic patients. A unique color map (sensor response) was obtained for each studied group, which can be monitored by a scanner. Moreover, a good correlation was observed between the colorimetric response resulting from the analysis of salivary composition and the fasting blood glucose (FBG) value measured by standard laboratory instruments. It was also possible to classify participants into two groups, including patients caused by diabetes and those were non-diabetic persons with a total accuracy of 88.9%. Statistical evaluations show that the multiple sensor can be employed as an effective and non-invasive device for continuous monitoring of diabetes, substantially in the elderly.

Accelerating synergistic effects of preconditioned mesenchymal stem cells with Crocin and dexamethasone in pulmonary epithelial cells injury.

Chemical warfare victims suffer from bronchiolitis and chronic pulmonary obstruction caused by sulfur mustard (SM) toxicity. Despite the mesenchymal stem cells capacity to alleviate inflammation, their low survival rate under oxidative stress severely limits their effectiveness. This study aimed to examine how natural (Crocin) and synthetic (Dexamethasone) antioxidants might affect MSC efficacy. MSCs were treated with the optimal doses of Crocin (Cr.), Dexamethasone (Dex.), and their combination. The A549 cells line was pretreated with the optimal dose of the CEES to mimic the lung disease. Then, the affected A549 cells were exposed to the preconditioned MSCs and conditioned media, and then their survival rates were estimated by MTTor2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Annexin-V PI apoptosis test was conducted for MSCs and A549 cells. Reactive Oxygen Species (ROS) assay and Enzyme-linked immunosorbent assay (ELISA) test demonstrated the percentage of production of ROS and the cytokines levels in A549/CEES, respectively. The results revealed significant increases in Cr. + Dex. treated MSCs (P < .01) and A549 cells treated with MSCs-CM/Cr/Dex (P < .01) groups' survival. The apoptosis rate and ROS production were reduced in the MSCs-CM/Cr/Dex. Also, considerable decreases in IL-1ß (P < .01) and IL-6 (P < .01) and a significant increase in IL-10 (P < .05) in treated A549/CEES by Cr/Dex and MSCs-CM/Cr/Dex supported the synergistic effects of Crocin and Dexamethasone.

Targeting glioblastoma multiforme using a novel fusion protein comprising interleukin-13 and staphylococcal enterotoxin B in vitro.

Targeting cell surface receptors with immunotoxins provides a novel, unique and highly potent treatment against cancers. A high expression of interleukin-13 (IL13) receptor α2 (IL13Rα2) has been reported in different types of cancers including glioblastoma multiforme (GBM). In this paper, to target IL13Rα2 on GBM cells, a fusion protein was generated comprising human IL13 and staphylococcal enterotoxin B (SEB), termed IL13-linker-SEB. The fusion protein was cloned into pET28a(+) and expressed in Escherichia coli strain BL21 (DE3); U251 (IL13Rα2-positive) and T98G (IL13Rα2-negative) GBM cell lines were employed and the functional activity of IL13-linker-SEB was evaluated by cell ELISA, cytotoxicity (MTT and LDH), apoptosis (flow cytometry and caspase-3 activity), adhesion, scratch and RT-PCR tests. SEB and chemotherapeutic drugs were employed to be compared to IL13-linker-SEB function. The IL13-linker-SEB exhibited higher binding affinity and cytotoxicity compared to SEB on U251 cells, although both recombinant proteins had shown similar behavior regarding T98G cells. Furthermore, the highest induction of apoptosis was observed in U251 cells treated with IL13-linker-SEB which was confirmed by Bax/Bcl-2 ratio. The expression of MMP2, MMP9 and VEGFR2 in U251 cells experienced a significant reduction after treatment with IL13-linker-SEB compared to SEB and T98G treated cells. The data showed that IL13-linker-SEB can be considered as a novel potential agent for GBM treatment; however, further research is needed to investigate the efficacy.

A comparative study of the arazyme-based fusion proteins with various ligands for more effective targeting cancer therapy: an in-silico analysis.

Background and purpose: Recently, the use of immunotoxins for targeted cancer therapy has been proposed, to find new anticancer drugs with high efficacy on tumor cells with minimal side effects on normal cells. we designed and compared several arazyme (AraA)-based fusion proteins with different ligands to choose the best-targeted therapy for interleukin 13 receptor alpha 2 (IL13Rα2)-overexpressed cancer cells. For this purpose, IL13Rα2 was selected as a receptor and IL13 and IL13.E13K were evaluated as native and mutant ligands, respectively. In addition, Pep-1 and A2b11 were chosen as the peptide ligands for targeted cancer therapy. Experimental approach: Several bioinformatics servers were used for designing constructs and optimization. The structures of the chimeric proteins were predicted and verified by I-TASSER, Q-Mean, ProSA, Ramachandran plot, and Verify3D program. Physicochemical properties, toxicity, and antigenicity were predicted by ProtParam, ToxinPred, and VaxiJen. HawkDock, LigPlot+, and GROMACS software were used for docking and molecular dynamics simulation of the ligand-receptor interaction. Findings/Results: The in silico results showed AraA-A2b11 has higher values of confidence score and Q-mean score was obtained for high-resolution crystal structures. All chimeric proteins were stable, non-toxic, and non-antigenic. AraA-(A(EAAAK)4ALEA(EAAAK)4A)2-IL13 retained its natural structure and based on ligand-receptor docking and molecular dynamic analysis, the binding ability of AraA-(A(EAAAK)4ALEA(EAAAK)4A)2-IL13 to IL13Rα2 was sufficiently strong. Conclusion and implications: Based on the bioinformatics result AraA-(A(EAAAK)4ALEA(EAAAK)4A)2-IL13 was a stable fusion protein with two separate domains and high affinity with the IL13Rα2 receptor. Therefore, AraA-(A(EAAAK)4ALEA(EAAAK)4A)2-IL13 fusion protein could be a new potent candidate for target cancer therapy.

Staphylococcal enterotoxin B as DNA vaccine against breast cancer in a murine model.

Recently, many efforts have been made to treat cancer using recombinant bacterial toxins and this strategy has been used in clinical trials of various cancers. Therapeutic DNA cancer vaccines are now considered as a promising strategy to activate the immune system against cancer. Cancer vaccines could induce specific and long-lasting immune responses against tumors. This study aimed to evaluate the antitumor potency of the SEB DNA vaccine as a new antitumor candidate against breast tumors in vivo. To determine the effect of the SEB construct on inhibiting tumor cell growth in vivo, the synthetic SEB gene, subsequent codon optimization, and embedding the cleavage sites were sub-cloned to an expression vector. Then, SEB construct, SEB, and PBS were injected into the mice. After being vaccinated, 4T1 cancer cells were injected subcutaneously into the right flank of mice. Then, the cytokine levels of IL-4 and IFN-γ were estimated by the ELISA method to evaluate the antitumor activity. The spleen lymphocyte proliferation, tumor size, and survival time were assessed. The concentration of IFN-γ in the SEB-Vac group showed a significant increase compared to other groups. The production of IL-4 in the group that received the DNA vaccine did not change significantly compared to the control group. The lymphocyte proliferation increased significantly in the mice group that received SEB construct than PBS control group (p < 0.001). While there was a meaningful decrease in tumor size (p < 0.001), a significant increase in tumor tissue necrosis (p < 0.01) and also in survival time of the animal model receiving the recombinant construct was observed. The designed SEB gene construct can be a new model vaccine for breast cancer because it effectively induces necrosis and produces specific immune responses. This structure does not hurt normal cells and is a safer treatment than chemotherapy and radiation therapy. Its slow and long-term release gently stimulates the immune system and cellular memory. It could be applied as a new model for inducing apoptosis and antitumor immunity to treat cancer.

A Novel Nanocomposite Scaffold Based on Polyurethane (PU) Containing Cobalt Nanoparticles (CoNPs) for Bone Tissue Engineering Applications.

BACKGROUND: Bone tissue engineering, as a relatively new approach, has focused on combining biodegradable scaffolds, cells, and biologically active molecules for the recovery of different damaged tissues, such as bone defects. Polyurethane (PU), as a synthetic polymer, benefits from a porous structure which impersonates bone's natural environment. However, PU lacks osteoinduction activities. Cobalt nanoparticles (CoNPs) stimulate angiogenesis and biomineralization, which greatly favors osteogenesis. METHODS: Here, we designed a novel scaffold based on PU and combined it with CoNPs for bone regeneration applications. The composition and structure of PU-CoNPs nanocomposite were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). MTT and AO data showed biocompatibility and enhanced viability and proliferation of fibroblasts on PU-CoNPs scaffold. Ascorbic acid-2-phosphate, ß-glycerophosphate, and dexamethasone-induced osteogenesis for 14 days. RESULTS: The alkaline phosphatase test asserts the increased mineralization of hADSCs cultured on PUCoNPs compared to pure PU scaffold. Further, the results disclosed an elevated osteogenic differentiation at the level of genes and proteins using immunocytochemical analysis (ICC) and quantitative real-time PCR (qPCR). CONCLUSION: These findings provide an evidence that PU-CoNPs nanocomposite might be a promising candidate for bone repair applications.

Improved Neural Differentiation of Human-induced Pluripotent Stem Cell [hiPSCs] on a Novel Polyurethane-based Scaffold Containing Iron Oxide Nanoparticles [Fe2O3 NPs].

BACKGROUND: Repair of the nervous system in humans has always been complicated and faced difficulties. Cell transplantation approaches using biocompatible scaffolds might be an attractive therapeutic strategy for neuronal regeneration. OBJECTIVE: We designed a cell delivery platform based on polyurethane [PU] and modified it with iron oxide nanoparticles [Fe2O3 NPs] for neural induction of human-induced pluripotent stem cells [hiPSC]. Forskolin, IBMX, and different ratios of FBS were employed to induce neurogenesis of hiPSCs. Neural differentiations were assessed at the level of genes and proteins. METHODS: As was shown by MTT colorimetric assay, the proliferation and viability of SNL 76/7 on PU/ Fe2O3 were superior in comparison with pure PU and Fe2O3. hiPSCs cultured with PU/Fe2O3 exhibited an elevated expression of ß3-tubulin, MAP2, NSE, OLIG2, as compared to controls. Furthermore, Acridine Orange staining assured the survival and viability of hiPSCs after 14 days of differentiation. RESULTS: All in all, our findings pointed out the biocompatibility and positive regulatory effect of PU/Fe2O3 on neural markers. CONCLUSION: We believe this scaffold could be a potential candidate for future nerve differentiation applications.

Safety and immunogenicity of a recombinant receptor-binding domain-based protein subunit vaccine (Noora vaccine™) against COVID-19 in adults: A randomized, double-blind, placebo-controlled, Phase 1 trial.

The development of a safe and effective vaccine is essential to protect populations against coronavirus disease 2019 (COVID-19). There are several vaccine candidates under investigation with different mechanisms of action. In the present study, we have evaluated the safety and immunogenicity of a recombinant receptor-binding domain (RBD)-based protein subunit vaccine (Noora vaccine) against COVID-19 in adults. This Phase 1 trial is a randomized, double-blind, placebo-controlled study to evaluate the safety and immunogenicity of the recombinant RBD-based protein subunit vaccine (Noora vaccine) against COVID-19 in healthy adults volunteers. Eligible participants were included in this study after evaluating their health status and considering the exclusion criteria. They were then randomized into three groups and received three doses of vaccine (80 µg, 120 µg, and placebo) on Days 0, 21, and 35. Primary outcomes including solicited, unsolicited, and medically attended adverse events were recorded during this study. Secondary outcomes including the humoral and cellular immunity (including anti-RBD IgG antibody and neutralizing antibody) were measured on Days 0, 21, 28, 35, 42, and 49 by using the ELISA kit and the Virus Neutralization Test (VNT) was performed on day 49. Totally 70 cases were included in this Phase 1 trial and 60 of them completed the study. Safety assessments showed no severe adverse events. Local pain at the vaccine injection site occurred in 80% of the vaccinated volunteers. Induration and redness at the injection site were the other adverse reactions of this vaccine. There was no significant difference between the studied groups regarding adverse reactions. Anti-RBD IgG antibody and neutralizing antibody assessment showed significant seroconversion in comparison to the placebo group (80%, and 100% respectively, p < 0.001). The cellular immunity panel also showed mild to moderate induction of TH1 responses and the VNT showed 78% of seroprotection. The results of this Phase 1 trial showed acceptable safety without serious adverse events and significant seroconversions in the humoral and cellular immunity panel. The dose of 80 µg is an appropriate dose for injection in the next phases of the trial.

Visual diagnosis of COVID-19 disease based on serum metabolites using a paper-based electronic tongue.

This study aims to use a paper-based sensor array for point-of-care detection of COVID-19 diseases. Various chemical compounds such as nanoparticles, organic dyes and metal ion complexes were employed as sensing elements in the array fabrication, capturing the metabolites of human serum samples. The viral infection caused the type and concentration of serum compositions to change, resulting in different color responses for the infected and control samples. For this purpose, 118 serum samples of COVID-19 patients and non-COVID controls both men and women with the age range of 14-88 years were collected. The serum samples were initially subjected to the sensor, followed by monitoring the variation in the color of sensing elements for 5 min using a scanner. By taking into consideration the statistical information, this method was capable of discriminating COVID-19 patients and control samples with 83.0% accuracy. The variation of age did not influence the colorimetric patterns. The desirable correlation was observed between the sensor responses and viral load values calculated by the PCR test, proposing a rapid and facile way to estimate the disease severity. Compared to other rapid detection methods, the developed assay is cost-effective and user-friendly, allowing for screening COVID-19 diseases reliably.

A new hydrogel with fluorapatite nanoparticles for osteogenic differentiation of human adipose-derived stem cells in tissue engineering field.

Since scaffolds are engineered to support functional tissue formation, their design and materials play an essential role in medical fields by providing different mechanical function. The aim of this study was to investigate the synthesis and structural characterization of collagen-gelatin (COL-GEL) composite scaffolds containing fluorapatite (FA) nanoparticles as well as evaluation of the osteogenic differentiation of human adipose-derived stem cells (hADSCs). First, the composite scaffolds were evaluated using Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. The cytotoxicity of scaffolds and various concentrations of FA nanoparticles was studied through MTT assay and acridine orange/ethidium bromide staining. Next, the differentiated hADSCs were analyzed using Alizarin red and von Kossa staining, calcium content assay, alkaline phosphatase (ALP) activity, real-time RT-PCR, and immunocytochemical analyses. According to the characterization analyses, the composite scaffolds were properly integrated. The results also illustrated that COL-GEL composite scaffolds in the presence of FA nanoparticles not only showed no cytotoxicity but also increased ALP activity and calcium deposition as well as the expression of osteogenic genes, including Runx2, Col-I, ALP, and osteocalcin and the synthesis of proteins such as osteocalcin and osteopontin in vitro. The obtained data were confirmed by Alizarin red and von Kossa staining. These results are very promising for further tissue engineering experiments, in which FA nanoparticle incorporation into COL-GEL composite scaffolds is a novel approach that improves the surface COL-GEL composite scaffolds for tissue engineering application in vitro.

Osteogenic differentiation of pre-conditioned bone marrow mesenchymal stem cells with Nisin on modified poly-L-lactic-acid nanofibers.

Introduction: Human bone marrow-derived mesenchymal stem cells (hBM-MSCs) are undifferentiated cells with self-renewing ability and multi-lineage differentiation beneficial for regenerative medicine. Nano scaffolds are novel materials employed in bone repair and regeneration. Nisin is a prebiotic that can increase stem cells' lifespan and proliferation. This study attempted to provide a proper strategy for bone marrow mesenchymal stem cells differentiation into the Osteocytes on a Poly-L-lactic-acid (PLLA) scaffold after pretreating with Nisin. Methods: MSC osteogenic differentiation was evaluated by measuring Calcium, Alkaline phosphatase, and quantitative tests such as Real-Time PCR, Acridine Orange, Alizarin Red, Von Kossa, and others. Results: The result of the MTT test showed that the optimal dose of Nisin prebiotic for the MSCs' preconditioning was 200 IU/mL on the 1st, 3rd, and 5th days of culture. Real-time PCR data indicated that the expression rate of ALP, Osteonectin, Osteocalcin, and Collagen I have increased in the presence of Nisin, while the RUNX-2 gene expression has decreased. Furthermore, the results of Alizarin Red and Von Kossa tests, as well as Scanning electron microscopy (SEM), revealed that the cell proliferation in the preconditioned samples with Nisin increased significantly. Conclusions: The study concluded that the cell proliferation and differentiation increased in samples pretreated with Nisin on the PLLA Nano scaffolds.