Nanotopography Influences Host-Pathogen Quorum Sensing and Facilitates Selection of Bioactive Metabolites in Mesenchymal Stromal Cells and Pseudomonas aeruginosa Co-Cultures.

Orthopedic implant-related bacterial infections and resultant antibiotic-resistant biofilms hinder implant-tissue integration and failure. Biofilm quorum sensing (QS) communication determines the pathogen colonization success. However, it remains unclear how implant modifications and host cells are influenced by, or influence, QS. High aspect ratio nanotopographies have shown to reduce biofilm formation of Pseudomonas aeruginosa, a sepsis causing pathogen with well-defined QS molecules. Producing such nanotopographies in relevant orthopedic materials (i.e., titanium) allows for probing QS using mass spectrometry-based metabolomics. However, nanotopographies can reduce host cell adhesion and regeneration. Therefore, we developed a polymer (poly(ethyl acrylate), PEA) coating that organizes extracellular matrix proteins, promoting bioactivity to host cells such as human mesenchymal stromal cells (hMSCs), maintaining biofilm reduction. This allowed us to investigate how hMSCs, after winning the race for the surface against pathogenic cells, interact with the biofilm. Our approach revealed that nanotopographies reduced major virulence pathways, such as LasR. The enhanced hMSCs support provided by the coated nanotopographies was shown to suppress virulence pathways and biofilm formation. Finally, we selected bioactive metabolites and demonstrated that these could be used as adjuncts to the nanostructured surfaces to reduce biofilm formation and enhance hMSC activity. These surfaces make excellent models to study hMSC-pathogen interactions and could be envisaged for use in novel orthopedic implants.

Epidemiologic and clinical updates on viral infections in Saudi Arabia.

In the past two decades, the world has witnessed devastating pandemics affecting the global healthcare infrastructure and disrupting society and the economy worldwide. Among all pathogens, viruses play a critical role that is associated with outbreaks due to their wide range of species, involvement of animal hosts, easily transmitted to humans, and increased rates of infectivity. Viral disease outbreaks threaten public health globally due to the challenges associated with controlling and eradicating them. Implementing effective viral disease control programs starts with ongoing surveillance data collection and analyses to detect infectious disease trends and patterns, which is critical for maintaining public health. Viral disease control strategies include improved hygiene and sanitation facilities, eliminating arthropod vectors, vaccinations, and quarantine. The Saudi Ministry of Health (MOH) and the Public Health Authority (also known as Weqayah) in Saudi Arabia are responsible for public health surveillance to control and prevent infectious diseases. The notifiable viral diseases based on the Saudi MOH include hepatitis diseases, viral hemorrhagic fevers, respiratory viral diseases, exanthematous viral diseases, neurological viral diseases, and conjunctivitis. Monitoring trends and detecting changes in these viral diseases is essential to provide proper interventions, evaluate the established prevention programs, and develop better prevention strategies. Therefore, this review aims to highlight the epidemiological updates of the recently reported viral infections in Saudi Arabia and to provide insights into the recent clinical treatment and prevention strategies.

Effect of TGF-ß3 on wound healing of bone cell monolayer in static and hydrodynamic shear stress conditions.

Introduction: Wound healing is characterized as a complicated and sophisticated biological process through which tissue heals and repairs itself after injury. However, the normal wound healing process relies on different growth factors as well as the presence of an accurate cytokine level to ensure appropriate cellular responses. In the case of wound healing, the effects of various growth factors have been studied, but the effects of transforming growth factor beta (TGF-ß) on wound healing have been found to be more significant because of its broad spectrum of impacts on healing the wounded tissues or skins. Methods: In the current study, the impact of TGF-ß3 in bone cells' wound healing was examined in vitro. Furthermore, the activities and characteristics of TGF-ß3, as well as those of related growth factors throughout this wound healing process, were studied under hydrodynamic shear stress conditions as well as static conditions of cultured bone cells. Results: We demonstrated that a positive outcome of TGF-ß3 treatment was found after 24 h under a static condition, while TGF-ß3 treatment was found to be effective under a dynamic condition for wound closure. In the case of the dynamic condition, a full wound closure was obtained after 18 h in both the control and TGF-ß3 treatment, while in the case of static conditions, wounds were found to remain open, even after 24 h, for both the control and TGF-ß3 treatment. Additionally, in the static condition, the wound closure rate with TGF-ß3 treatment was found to be quicker than that of the control flask, which implies that wound healing can be postponed in the static condition. In the dynamic condition, the wound healing process became more rapid in a cultured cell environment. Conclusion: The synergistic effect of TGF-ß3 and hydrodynamic shear stress conditions had a positive impact on increasing wound healing and improving the rate of wound closure.

Bone-nerve crosstalk: a new state for neuralizing bone tissue engineering-A mini review.

Neuro bone tissue engineering is a multidisciplinary field that combines both principles of neurobiology and bone tissue engineering to develop innovative strategies for repairing and regenerating injured bone tissues. Despite the fact that regeneration and development are considered two distinct biological processes, yet regeneration can be considered the reactivation of development in later life stages to restore missing tissues. It is noteworthy that the regeneration capabilities are distinct and vary from one organism to another (teleost fishes, hydra, humans), or even in the same organism can vary dependent on the injured tissue itself (Human central nervous system vs. peripheral nervous system). The skeletal tissue is highly innervated, peripheral nervous system plays a role in conveying the signals and connecting the central nervous system with the peripheral organs, moreover it has been shown that they play an important role in tissue regeneration. Their regeneration role is conveyed by the different cells' resident in it and in its endoneurium (fibroblasts, microphages, vasculature associated cells, and Schwann cells) these cells secrete various growth factors (NGF, BDNF, GDNF, NT-3, and bFGF) that contribute to the regenerative phenotype. The peripheral nervous system and central nervous system synchronize together in regulating bone homeostasis and regeneration through neurogenic factors and neural circuits. Receptors of important central nervous system peptides such as Serotonin, Leptin, Semaphorins, and BDNF are expressed in bone tissue playing a role in bone homeostasis, metabolism and regeneration. This review will highlight the crosstalk between peripheral nerves and bone in the developmental stages as well as in regeneration and different neuro-bone tissue engineering strategies for repairing severe bone injuries.

Immunoprofiling of cytokines, chemokines, and growth factors in female patients with systemic lupus erythematosus- a pilot study.

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease affecting different organ systems. This study aimed to determine the concentrations of 30 different human cytokines, chemokines, and growth factors in human plasma to understand the role of these markers in the pathogenicity of SLE using Luminex Multiple Analyte Profiling (xMAP) technology. Plasma samples were obtained from patients with SLE (n = 28), osteoarthritis (OA) (n = 9), and healthy individuals (n = 12) were obtained. High levels of TNF, IL-6, IFN-γ, INF-α, IL-4, IL-5, IL-13, IL-8, IP-10, MIG, MCP-1, MIP-1ß, GM-CSF, G-CSF, EGF, VEGF, IL-12, IL-1RA, and IL-10 was detected in SLE patients compared with the OA and healthy control groups. xMAP analysis has been used to address the differential regulation of clinical heterogeneity and immunological phenotypes in SLE patients. In addition, complete disease phenotyping information along with cytokine immune profiles would be useful for developing personalized treatments for patients with SLE.

Enhanced and Stem-Cell-Compatible Effects of Nature-Inspired Antimicrobial Nanotopography and Antimicrobial Peptides to Combat Implant-Associated Infection.

Nature-inspired antimicrobial surfaces and antimicrobial peptides (AMPs) have emerged as promising strategies to combat implant-associated infections. In this study, a bioinspired antimicrobial peptide was functionalized onto a nanospike (NS) surface by physical adsorption with the aim that its gradual release into the local environment would enhance inhibition of bacterial growth. Peptide adsorbed on a control flat surface exhibited different release kinetics compared to the nanotopography, but both surfaces showed excellent antibacterial properties. Functionalization with peptide at micromolar concentrations inhibited Escherichia coli growth on the flat surface, Staphylococcus aureus growth on the NS surface, and Staphylococcus epidermidis growth on both the flat and NS surfaces. Based on these data, we propose an enhanced antibacterial mechanism whereby AMPs can render bacterial cell membranes more susceptible to nanospikes, and the membrane deformation induced by nanospikes can increase the surface area for AMPs membrane insertion. Combined, these effects enhance bactericidal activity. Since functionalized nanostructures are highly biocompatible with stem cells, they make promising candidates for next generation antibacterial implant surfaces.

Role of Polymers in Microfluidic Devices.

Polymers are sustainable and renewable materials that are in high demand due to their excellent properties. Natural and synthetic polymers with high flexibility, good biocompatibility, good degradation rate, and stiffness are widely used for various applications, such as tissue engineering, drug delivery, and microfluidic chip fabrication. Indeed, recent advances in microfluidic technology allow the fabrication of polymeric matrix to construct microfluidic scaffolds for tissue engineering and to set up a well-controlled microenvironment for manipulating fluids and particles. In this review, polymers as materials for the fabrication of microfluidic chips have been highlighted. Successful models exploiting polymers in microfluidic devices to generate uniform particles as drug vehicles or artificial cells have been also discussed. Additionally, using polymers as bioink for 3D printing or as a matrix to functionalize the sensing surface in microfluidic devices has also been mentioned. The rapid progress made in the combination of polymers and microfluidics presents a low-cost, reproducible, and scalable approach for a promising future in the manufacturing of biomimetic scaffolds for tissue engineering.

Deciphering SARS CoV-2-associated pathways from RNA sequencing data of COVID-19-infected A549 cells and potential therapeutics using in silico methods.

BACKGROUND: Coronavirus (CoV) disease (COVID-19) identified in Wuhan, China, in 2019, is mainly characterized by atypical pneumonia and severe acute respiratory syndrome (SARS) and is caused by SARS CoV-2, which belongs to the Coronaviridae family. Determining the underlying disease mechanisms is central to the identification and development of COVID-19-specific drugs for effective treatment and prevention of human-to-human transmission, disease complications, and deaths. METHODS: Here, next-generation RNA sequencing (RNA Seq) data were obtained using Illumina Next Seq 500 from SARS CoV-infected A549 cells and mock-treated A549 cells from the Gene Expression Omnibus (GEO) (GSE147507), and quality control (QC) was assessed before RNA Seq analysis using CLC Genomics Workbench 20.0. Differentially expressed genes (DEGs) were imported into BioJupies to decipher COVID-19 induced signaling pathways and small molecules derived from chemical synthesis or natural sources to mimic or reverse COVID -19 specific gene signatures. In addition, iPathwayGuide was used to identify COVID-19-specific signaling pathways, as well as drugs and natural products with anti-COVID-19 potential. RESULTS: Here, we identified the potential activation of upstream regulators such as signal transducer and activator of transcription 2 (STAT2), interferon regulatory factor 9 (IRF9), and interferon beta (IFNß), interleukin-1 beta (IL-1ß), and interferon regulatory factor 3 (IRF3). COVID-19 infection activated key infectious disease-specific immune-related signaling pathways such as influenza A, viral protein interaction with cytokine and cytokine receptors, measles, Epstein-Barr virus infection, and IL-17 signaling pathway. Besides, we identified drugs such as prednisolone, methylprednisolone, diclofenac, compound JQ1, and natural products such as Withaferin-A and JinFuKang as candidates for further experimental validation of COVID-19 therapy. CONCLUSIONS: In conclusion, we have used the in silico next-generation knowledge discovery (NGKD) methods to discover COVID-19-associated pathways and specific therapeutics that have the potential to ameliorate the disease pathologies associated with COVID-19.

Implications of SARS-CoV-2 infection on the clinical, hematological, and inflammatory parameters in COVID-19 patients: A retrospective cross-sectional study.

BACKGROUND: The current coronavirus pandemic (COVID-19) was caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2). COVID-19 is characterized by atypical pneumonia, mild colds, and more severe illnesses, such as severe acute respiratory distress, thrombosis, organ failure, and various secondary bacterial and fungal infections. Notably, the severity of COVID-19 in different age groups is not well known, and the validity of clinical laboratory data remains unclear. METHODS: In this retrospective cross-sectional study, we examined differential regulation of clinical, hematologic, and inflammatory biomarkers in COVID-19 patients. We divided 104 COVID-19 patients into five different groups according to age (0-17, 18-45, 46-65, 66-79, and >80 years). Baseline data (sex, comorbidities, intensive care admission, and medications), hematologic markers, liver, and renal function tests, coagulation, and inflammatory markers were examined in these groups. Receiver operator characteristic (ROC) analysis was used to determine the optimal threshold for predicting COVID-19 biological markers. RESULTS: We found that the highest percentage (45%) of COVID-19 patients was in the age group of 46-65 years. The hematologic parameters (WBC, HB, and PLT) were normal between the patient groups. The area under the curve in ROC analysis showed significant differences in the levels of creatine, GGT, BUN, CRP, D-dimer, ferritin, AST, and procalcitonin between the patients of age groups 46-65 and 66-79 years. Renal biomarkers were significantly high in most patients, regardless of age. In contrast, the liver biomarkers, did not differ significantly between patient groups. CONCLUSION: The main finding of our study is that laboratory parameters such as GGT, creatinine, BUN, CRP, procalcitonin, ferritin and D-dimer were differentially regulated in COVID -19 patients of different age groups. Importantly, these laboratory parameters may help as clinical predictors to assess the severity of the disease in the population. We conclude here that age is an important factor influencing COVID-19 severity.

Materials-driven fibronectin assembly on nanoscale topography enhances mesenchymal stem cell adhesion, protecting cells from bacterial virulence factors and preventing biofilm formation.

Post-operative infection is a major complication in patients recovering from orthopaedic surgery. As such, there is a clinical need to develop biomaterials for use in regenerative surgery that can promote mesenchymal stem cell (MSC) osteospecific differentiation and that can prevent infection caused by biofilm-forming pathogens. Nanotopographical approaches to pathogen control are being identified, including in orthopaedic materials such as titanium and its alloys. These topographies use high aspect ratio nanospikes or nanowires to prevent bacterial adhesion but these features also significantly reduce MSC adhesion and activity. Here, we use a poly (ethyl acrylate) (PEA) polymer coating on titanium nanowires to spontaneously organise fibronectin (FN) and to deliver bone morphogenetic protein 2 (BMP2) to enhance MSC adhesion and osteospecific signalling. Using a novel MSC-Pseudomonas aeruginosa co-culture, we show that the coated nanotopographies protect MSCs from cytotoxic quorum sensing and signalling molecules, enhance MSC adhesion and osteoblast differentiation and reduce biofilm formation. We conclude that the PEA polymer-coated nanotopography can both support MSCs and prevent pathogens from adhering to a biomaterial surface, thus protecting from biofilm formation and bacterial infection, and supporting osteogenic repair.

An Overview of RNA-Based Scaffolds for Osteogenesis.

Tissue engineering provides new hope for the combination of cells, scaffolds, and bifactors for bone osteogenesis. This is achieved by mimicking the bone's natural behavior in recruiting the cell's molecular machinery for our use. Many researchers have focused on developing an ideal scaffold with specific features, such as good cellular adhesion, cell proliferation, differentiation, host integration, and load bearing. Various types of coating materials (organic and non-organic) have been used to enhance bone osteogenesis. In the last few years, RNA-mediated gene therapy has captured attention as a new tool for bone regeneration. In this review, we discuss the use of RNA molecules in coating and delivery, including messenger RNA (mRNA), RNA interference (RNAi), and long non-coding RNA (lncRNA) on different types of scaffolds (such as polymers, ceramics, and metals) in osteogenesis research. In addition, the effect of using gene-editing tools-particularly CRISPR systems-to guide RNA scaffolds in bone regeneration is also discussed. Given existing knowledge about various RNAs coating/expression may help to understand the process of bone formation on the scaffolds during osseointegration.

Decoding the Role of Sphingosine-1-Phosphate in Asthma and Other Respiratory System Diseases Using Next Generation Knowledge Discovery Platforms Coupled With Luminex Multiple Analyte Profiling Technology.

Sphingosine-1-phosphate (S1P) is a pleiotropic sphingolipid derived by the phosphorylation of sphingosine either by sphingosine kinase 1 (SPHK1) or SPHK2. Importantly, S1P acts through five different types of G-protein coupled S1P receptors (S1PRs) in immune cells to elicit inflammation and other immunological processes by enhancing the production of various cytokines, chemokines, and growth factors. The airway inflammation in asthma and other respiratory diseases is augmented by the activation of immune cells and the induction of T-helper cell type 2 (Th2)-associated cytokines and chemokines. Therefore, studying the S1P mediated signaling in airway inflammation is crucial to formulate effective treatment and management strategies for asthma and other respiratory diseases. The central aim of this study is to characterize the molecular targets induced through the S1P/S1PR axis and dissect the therapeutic importance of this key axis in asthma, airway inflammation, and other related respiratory diseases. To achieve this, we have adopted both high throughput next-generation knowledge discovery platforms such as SwissTargetPrediction, WebGestalt, Open Targets Platform, and Ingenuity Pathway Analysis (Qiagen, United States) to delineate the molecular targets of S1P and further validated the upstream regulators of S1P signaling using cutting edge multiple analyte profiling (xMAP) technology (Luminex Corporation, United States) to define the importance of S1P signaling in asthma and other respiratory diseases in humans.

Rapid immunoprofiling of cytokines, chemokines and growth factors in patients with active rheumatoid arthritis using Luminex Multiple Analyte Profiling technology for precision medicine.

OBJECTIVES: Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease of unknown etiology, characterised by symmetric erosive synovitis, leading inevitably to the destruction of cartilage and bone as well as bursa and tendon sheaths of joints. Our aim of this study was to decipher the differential expression of cytokines, chemokines and growth factors in the plasma of RA patients with active disease, using magnetic bead-based Luminex Multiple Analyte Profiling (xMAP) technology, for precision medicine. METHODS: We obtained plasma samples from RA patients (n=25) from the Rheumatology Clinic at the King Abdulaziz University Hospital (KAUH), Jeddah, Kingdom of Saudi Arabia (KSA) after written informed consent for their inclusion in this study. Besides, we have used the plasma samples from inflammatory osteoarthritis (OA) patients (n=10) and healthy volunteers (n=10) for comparison analyses. Plasma samples were examined using the Human Cytokine Magnetic 30-plex panel (Novex®), Invitrogen, USA) and analysed by MAGPIX® instrument (Luminex Corporation, USA). RESULTS: Though several pro-inflammatory cytokines, chemokines and growth factors present in the 30plex magnetic bead panel were not significantly (p>0.05) increased in the plasma of RA patients, the levels of plasma Th1 associated proinflammatory cytokines TNFα, and IL-6 and Th2 associated cytokines such as IL-4, IL-5 and IL-13 were significantly (p<0.05) upregulated compared to OA and normal controls. The proinflammatory IL-12 as well as anti-inflammatory IL-10 and IL-1RA were significantly (p<0.05) upregulated in the plasma of RA patients compared to normal controls. Also, the chemokines such as IP-10, RANTES and IL-8 as well as growth factors such as EGF, and VEGF were significantly (p<0.05) increased in RA. CONCLUSIONS: The MAGPIX data showed that the cytokines, chemokines and growth factors were differentially regulated systemically in patients with active RA compared to OA and normal controls. Hence, the Luminex xMAP technology-based multiplex immunoassays offer clues to formulate effective therapeutic strategies for RA patients with active disease irrespective of their treatment regimen and duration of treatment and, thus, an indispensable tool in precision medicine.

Antibacterial surface modification of titanium implants in orthopaedics.

The use of biomaterials in orthopaedics for joint replacement, fracture healing and bone regeneration is a rapidly expanding field. Infection of these biomaterials is a major healthcare burden, leading to significant morbidity and mortality. Furthermore, the cost to healthcare systems is increasing dramatically. With advances in implant design and production, research has predominately focussed on osseointegration; however, modification of implant material, surface topography and chemistry can also provide antibacterial activity. With the increasing burden of infection, it is vitally important that we consider the bacterial interaction with the biomaterial and the host when designing and manufacturing future implants. During this review, we will elucidate the interaction between patient, biomaterial surface and bacteria. We aim to review current and developing surface modifications with a view towards antibacterial orthopaedic implants for clinical applications.

Impact of surface topography and coating on osteogenesis and bacterial attachment on titanium implants.

Titanium (Ti) plays a predominant role as the material of choice in orthopaedic and dental implants. Despite the majority of Ti implants having long-term success, premature failure due to unsuccessful osseointegration leading to aseptic loosening is still too common. Recently, surface topography modification and biological/non-biological coatings have been integrated into orthopaedic/dental implants in order to mimic the surrounding biological environment as well as reduce the inflammation/infection that may occur. In this review, we summarize the impact of various Ti coatings on cell behaviour both in vivo and in vitro. First, we focus on the Ti surface properties and their effects on osteogenesis and then on bacterial adhesion and viability. We conclude from the current literature that surface modification of Ti implants can be generated that offer both osteoinductive and antimicrobial properties.

Embedded Disposable Functionalized Electrochemical Biosensor with a 3D-Printed Flow Cell for Detection of Hepatic Oval Cells (HOCs).

Hepatic oval cells (HOCs) are considered the progeny of the intrahepatic stem cells that are found in a small population in the liver after hepatocyte proliferation is inhibited. Due to their small number, isolation and capture of these cells constitute a challenging task for immunosensor technology. This work describes the development of a 3D-printed continuous flow system and exploits disposable screen-printed electrodes for the rapid detection of HOCs that over-express the OV6 marker on their membrane. Multiwall carbon nanotube (MWCNT) electrodes have a chitosan film that serves as a scaffold for the immobilization of oval cell marker antibodies (anti-OV6-Ab), which enhance the sensitivity of the biomarker and makes the designed sensor specific for oval cells. The developed sensor can be easily embedded into the 3D-printed flow cell to allow cells to be exposed continuously to the functionalized surface. The continuous flow is intended to increase capture of most of the target cells in the specimen. Contact angle measurements were performed to characterize the nature and quality of the modified sensor surface, and electrochemical measurements (cyclic voltammetry (CV) and square wave voltammetry (SWV)) were performed to confirm the efficiency and selectivity of the fabricated sensor to detect HOCs. The proposed method is valuable for capturing rare cells and could provide an effective tool for cancer diagnosis and detection.

Combination of Mesenchymal Stem Cells, Cartilage Pellet and Bioscaffold Supported Cartilage Regeneration of a Full Thickness Articular Surface Defect in Rabbits.

BACKGROUND: Mesenchymal stem cells (MSCs) and/or biological scaffolds have been used to regenerate articular cartilage with variable success. In the present study we evaluated cartilage regeneration using a combination of bone marrow (BM)-MSCs, HyalofastTM and/or native cartilage tissue following full thickness surgical cartilage defect in rabbits. METHODS: Full-thickness surgical ablation of the medial-tibial cartilage was performed in New Zealand white (NZW) rabbits. Control rabbits (Group-I) received no treatment; Animals in other groups were treated as follows. Group-II: BM-MSCs (1 × 106 cells) + HyalofastTM; Group-III: BMMSCs (1 × 106 cells) + cartilage pellet (CP); and Group-IV: BM-MSCs (1 × 106 cells) + HyalofastTM + CP. Animals were sacrificed at 12 weeks and cartilage regeneration analyzed using histopathology, International Cartilage Repair Society (ICRS-II) score, magnetic resonance observation of cartilage repair tissue (MOCART) score and biomechanical studies. RESULTS: Gross images showed good tissue repair (Groups IV > III > Group II) and histology demonstrated intact superficial layer, normal chondrocyte arrangement, tidemark and cartilage matrix staining (Groups III and IV) compared to the untreated control (Group I) respectively. ICRS-II score was 52.5, 65.0, 66 and 75% (Groups I-IV) and the MOCART score was 50.0, 73.75 and 76.25 (Groups II-IV) respectively. Biomechanical properties of the regenerated cartilage tissue in Group IV closed resembled that of a normal cartilage. CONCLUSION: HyalofastTM together with BM-MSCs and CP led to efficient cartilage regeneration following full thickness surgical ablation of tibial articular cartilage in vivo in rabbits. Presence of hyaluronic acid in the scaffold and native microenvironment cues probably facilitated differentiation and integration of BM-MSCs.

Mesenchymal stem cell therapy of hepatocellular carcinoma in rats: Detection of cell homing and tumor mass by magnetic resonance imaging using iron oxide nanoparticles.

BACKGROUND: Bone marrow-derived mesenchymal stem cells (MSCs) are reported to improve hepatic fibrosis, and may impact the signaling mechanisms leading to the induction of hepatocellular carcinoma (HCC) in animal models of liver cirrhosis. OBJECTIVES: The aim of this study was to clarify and explain the therapeutic role played by MSCs in hepatic cirrhosis and HCC by tracking them using nanoparticles. MATERIAL AND METHODS: Liver cirrhosis and HCC were established in rats with the use of carbon tetrachloride and diethylnitrosamine injection. Magnetic resonance imaging (MRI) was used to track nanoparticlelabeled MSCs in the intact animal following injection and to monitor the changes in the hepatic parenchyma. RESULTS: Labeling of MSCs with iron oxide nanoparticles did not adversely affect their viability and proliferation. MRI indicated a significant reduction in tumor mass in the labeled MSCs group compared to the control group. Histopathologic examination of the liver, following MSCs treatment, showed an apparently normal looking liver with no evidence of neoplastic cellular changes. The biochemical results support these findings. CONCLUSIONS: This work documents that MSCs could be labeled with nanoparticles and traced in normal and cirrhotic liver and in liver with HCC in animals using MRI. MRI monitors the homing and localization of MSCs in the liver. MSCs infusion in animal models of cirrhosis and carcinoma may prove to be useful in limiting the cirrhotic process. Also, it may have a possible therapeutic potential on the carcinogenic process.

Mesenchymal stem cells: a future experimental exploration for recession of diabetic nephropathy.

BACKGROUND: The progresses made in stem cell therapy offer an innovative approach and exhibit great potential for the repair of damaged organs and tissues. This study was conducted with a view to find the mechanisms responsible for the effectiveness of bone marrow-derived mesenchymal stem cells (BM-MSCs) in the suppression of diabetes and experimentally-induced diabetic nephropathy. METHODS: To realize this objective, diabetic and diabetic nephropathy subject groups that underwent MSC treatment were studied through numerous biochemistry and molecular genetics analyses. RESULTS: The findings show that, relative to the control groups, the rats in the diabetic and diabetic nephropathy groups treated with stem cells infused with BM-MSCs showed a significant reversal in the levels of their insulin, glucose, heme-oxygenase-1 (HO-1) serum, and advanced glycation end product (AGEP). Moreover, BM-MSC therapy was also found to have a definite positive effect on the kidney functions. In addition, it also corresponded with a significant decrease in the availability of certain growth factors, namely the fibroblast growth factor (FGF), the platelet-derived growth factor (PDGF), and the transforming growth factor-ß (TGF-ß). BM-MSC treatment also improved the levels of expression of monocyte chemoatractant-1 (MCP-1) and interleukin-8 (IL-8) genes within kidney tissues. Lastly, the treatment recovered the organizational structure of the kidney and pancreas, a result demonstrated by a histopathological analysis. These results greatly coincide with those obtained through the biochemistry and molecular genetics analyses. CONCLUSION: Treatment using BM-MSCs is determined to be definitely effective in cases of diabetes and diabetic nephropathy.