Current Research of the Renin-Angiotensin System Effect on Stem Cell Therapy

The renin-angiotensin system (RAS) is a chief regulator of the cardiovascular system and body fluid homeostasis. Stem/progenitor cell therapy has pointed towards a novel tool for medical and therapeutic intervention. In addition to the physiological and pathological role of the RAS and its pharmacological inhibitors, the proliferation, differentiation in stem cells is mediated through various cell-signalling pathways. This book chapter reviews the new role of RAS components, distinct from other common roles by considering its regulating impact on the several signalling pathways involved in different body tissues, as well as in stem cell therapy

Cell junctions and oral health

The oral cavity and its appendices are exposed to considerable environmental and mechanical stress. This frequently involves cell junctions, which are goalkeepers of tissue homeostasis. Among those, gap junctions permit the exchange of compounds between cells, thereby controlling processes such as cell growth and differentiation. Tight junctions restrict paracellular transportation and inhibit movement of integral membrane proteins between the different plasma membrane poles. Adherens junctions attach cells one to another and provide a solid backbone for resisting to mechanistical stress. The integrity of oral mucosa, normal tooth development and saliva secretion depends on the proper function of all these types of cell junctions. Furthermore, deregulation of junctional proteins and/or mutations in their genes can alter tissue functioning and may result in various human disorders, including dental and periodontal problems, salivary gland malfunction, hereditary and infectious diseases as well as tumorigenesis. The present paper reviews the role of cell junctions in the (patho)physiology of the oral cavity and its appendices

Cytoprotective Properties of Carnosine against Isoniazid-Induced Toxicity in Primary Cultured Rat Hepatocytes

Background: Drug-induced liver injury is a critical clinical complication. Hence, finding new and safe protective agents with potential clinical application is of value. Isoniazid (INH) is an antituberculosis agent widely used against Mycobacterium tuberculosis infection in human. On the other hand, hepatotoxicity is a clinical complication associated with isoniazid therapy. Oxidative stress and its associated events are major mechanisms identified for INH-induced liver injury. Carnosine is an endogenously found peptide widely investigated for its hepatoprotective effects. On the other hand, robust antioxidant and cytoprotective effects have been attributed to this peptide. Methods: The current study designed to evaluate the potential cytoprotective properties of carnosine against INH-induced cytotoxicity in drug-exposed primary cultured rat hepatocytes. Primary cultured rat hepatocytes were incubated with INH (1.2 mM). Results: INH treatment caused significant increase in cell death and lactate dehydrogenase (LDH) release. On the other hand, it was found that markers of oxidative stress including reactive oxygen species were significantly increased in INH-treated cells. Cellular glutathione reservoirs were also depleted in INH-treated group. Carnosine treatment (50 and 100 µM) significantly diminished INH-induced oxidative stress and cytotoxicity. Conclusion: These data mention carnosine as a potential protective agent with therapeutic capability against INH hepatotoxicity

Curcumin Nanocrystals: Production, Physicochemical Assessment, and In Vitro Evaluation of the Antimicrobial Effects against Bacterial Loading of the Implant Fixture

Background: This study aimed to prepare and study physicochemical properties as well as the antibacterial action of curcumin nanocrystals inside the implant fixture against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Enterococcus faecalis (E. faecalis). Methods: Curcumin nanocrystals were prepared via precipitation combined with the spray drying method. The produced curcumin nanocrystals were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Moreover, the in vitro antimicrobial effect of curcumin nanocrystals inside the implant fixture was assessed against E. coli, S. aureus, and E. faecalis. All implant-abutment assemblies were immersed in bacterial suspensions and were incubated at 24, 48, and 72 h. The contents of each implant were cultured to count the colony of bacteria at 37 ◦C for 24 h. Results: The prepared curcumin nanocrystals with a mean particle size of 95 nm and spherical morphology exhibited a removal rate of 99.99% for all bacteria. In addition, the colony-forming unit (CFU) of bacteria in exposure to nanocrystals significantly was reduced (p < 0.010) by increasing the time. Conclusions: Curcumin nanocrystals can be used inside the implant fixture as an antimicrobial agent in order to more stabilization of the implant

The Use of Infrapatellar Fat Pad-Derived Mesenchymal Stem Cells in Articular Cartilage Regeneration: A Review.

Cartilage is frequently damaged with a limited capacity for repair. Current treatment strategies are insufficient as they form fibrocartilage as opposed to hyaline cartilage, and do not prevent the progression of degenerative changes. There is increasing interest in the use of autologous mesenchymal stem cells (MSC) for tissue regeneration. MSCs that are used to treat articular cartilage defects must not only present a robust cartilaginous production capacity, but they also must not cause morbidity at the harvest site. In addition, they should be easy to isolate from the tissue and expand in culture without terminal differentiation. The source of MSCs is one of the most important factors that may affect treatment. The infrapatellar fat pad (IPFP) acts as an important reservoir for MSC and is located in the anterior compartment of the knee joint in the extra-synovial area. The IPFP is a rich source of MSCs, and in this review, we discuss studies that demonstrate that these cells have shown many advantages over other tissues in terms of ease of isolation, expansion, and chondrogenic differentiation. Future studies in articular cartilage repair strategies and suitable extraction as well as cell culture methods will extend the therapeutical application of IPFP-derived MSCs into additional orthopedic fields, such as osteoarthritis. This review provides the latest research concerning the use of IPFP-derived MSCs in the treatment of articular cartilage damage, providing critical information for the field to grow

Editorial: Biological/chemical-based metallic nanoparticles synthesis, characterization, and environmental applications

[No Abstract Available]We would like to express our gratitude to the authors of the articles that were published on this Research Topic for their original and insightful research, and for the methodical updates in the review articles, all of which have helped to significantly advance our understanding of this vital scientific area. We would also like to emphasize how the utmost professionalism of the reviewers enabled the authors to meet the journal’s highest standards. Finally, we would like to express our gratitude for the efforts made by the journal’s Editorial Board and Management, who supported the entire process with precision and expertise and greatly enhanced the caliber of this Research Topic

The Use of Nanomaterials in Tissue Engineering for Cartilage Regeneration; Current Approaches and Future Perspectives

The repair and regeneration of articular cartilage represent important challenges for orthopedic investigators and surgeons worldwide due to its avascular, aneural structure, cellular arrangement, and dense extracellular structure. Although abundant efforts have been paid to provide tissue-engineered grafts, the use of therapeutically cell-based options for repairing cartilage remains unsolved in the clinic. Merging a clinical perspective with recent progress in nanotechnology can be helpful for developing efficient cartilage replacements. Nanomaterials, < 100 nm structural elements, can control different properties of materials by collecting them at nanometric sizes. The integration of nanomaterials holds promise in developing scaffolds that better simulate the extracellular matrix (ECM) environment of cartilage to enhance the interaction of scaffold with the cells and improve the functionality of the engineered-tissue construct. This technology not only can be used for the healing of focal defects but can also be used for extensive osteoarthritic degenerative alterations in the joint. In this review paper, we will emphasize the recent investigations of articular cartilage repair/regeneration via biomaterials. Also, the application of novel technologies and materials is discussed

Simulation and modeling of physiological processes of vital organs in organ-on-a-chip biosystem

The limited adequacy of animal cell cultures and models to mimic the complexity of human bodies in laboratory conditions has emphasized researchers to find its quintessential bioelectronic alternative with improved competence. In this regard, tissue engineering has emerged as one of the most precise biomaterial technologies in terms of creating new tissues to model vital organs. An organ-on-a-chip biosystem has shown a plethora of applications in tissue engineering and drug delivery. Organ-on-a-chip is a microfluidic device that provides a completely controlled microenvironment, similar to the natural tissues for the cultured cells of an organ, by amalgamating cell biology and biomaterial science. The device contains several microchambers and microchannels embedded in a layer of a biocompatible polymer, such as polydimethylsiloxane. Microchambers house the cells, while microchannels provide nutrients and growth factors. Over the past few years, organ-on-a-chip technology has displayed ample applications in the field of biomedicine, not only by simulating the normal functions of disparate organs, but also by understanding the inter-relation between diversified systems. In this review, we have spotlighted recent advancements and applications of organ-on-a-chip biosystems to construct physiological models for the heart, lung, kidney, liver, and brain. Part of this review is also concentrated on abridging the desperate essentiality as well as future perspectives of organ-on-a-chip technology in biomedicine, disease modeling, and drug development process

A Comprehensive Review of Detection Methods for SARS-CoV-2

Recently, the outbreak of the coronavirus disease 2019 (COVID-19), caused by the SARSCoV-2 virus, in China and its subsequent spread across the world has caused numerous infections and deaths and disrupted normal social activity. Presently, various techniques are used for the diagnosis of SARS-CoV-2 infection, with various advantages and weaknesses to each. In this paper, we summarize promising methods, such as reverse transcription-polymerase chain reaction (RT-PCR), serological testing, point-of-care testing, smartphone surveillance of infectious diseases, nanotechnology-based approaches, biosensors, amplicon-based metagenomic sequencing, smartphone, and wastewaterbased epidemiology (WBE) that can also be utilized for the detection of SARS-CoV-2. In addition, we discuss principles, advantages, and disadvantages of these detection methods, and highlight the potential methods for the development of additional techniques and products for early and fast detection of SARS-CoV-2