An overview on different strategies for the stemness maintenance of MSCs

Recent evidence suggests that mesenchymal stem cells (MSCs) have promising therapeutic potential for a broad range of diseases. Because the percentage of MSCs obtained from tissues is very low for cell therapy applications, ex vivo expansion of MSCs is necessary, but aging, loss of stemness and undesired differentiation of them during in vitro cultivation reduces their effectiveness. For achieving ideal therapeutic potential of MSCs in tissue regenerative purposes, it is necessary to retain their stemness properties in vitro. This review emphasis on the last updates in preserving the self-renewal capability of stem cells through in vitro expansion with different parameters

Vancomycin Capped with Silver Nanoparticles as an Antibacterial Agent against Multi-Drug Resistance Bacteria

Purpose: Many antimicrobial medications are available to combat infections. However, the indiscriminate use of antibiotics has produced antibiotic resistance in the case of many bacterial pathogens. This study focuses on the development of nanoparticles (NPs) that enhance the in vitro antibiotic activity of vancomycin against multi-drug resistant (MDR) organisms. Methods: Spherical shaped thioglycolic acid-stabilized silver nanoparticles (TGA-AgNPs) were prepared by using a simple chemical reduction method. Then, vancomycin was conjugated to the terminal carboxyl of TGA in the presence of N-Hydroxysuccinimide (NHS) and N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC). Afterwards, the antibacterial activity of these nanoconjugates was examined by using the minimum inhibitory concentration (MIC) assay against MDR bacteria. Results: The rate of vancomycin bound to the AgNPs was 19.6%. The MIC values of vancomycin (Van)-capped AgNPs against tested pathogens were in the range of (3.2, 1.6, 0.8, 0.4, 0.2, 0.1, 0.05, and 0.025 µl/ml). The MIC was 0.1 µg/ml for VRE, MIC≤0.02 µg/ml for MRSE, and 0.05 µg/ml for S. aureus. The MIC corresponded to the MBC for all bacterial species. Conclusion: This study indicated that some antimicrobial agents like vancomycin can be conjugated with AgNPs. This can lead to increased antimicrobial activity against MDR microorganisms

A bioengineering method for modeling alveolar Rhabdomyosarcoma and assessing chemotherapy responses

Rhabdomyosarcoma (RMS) is the most common pediatric soft-tissue malignant tumor. Treatment of RMS usually includes primary tumor resection along with systemic chemotherapy. Two-dimensional (2D) cell culture systems and animal models have been extensively used for investigating the potential efficacy of new RMS treatments. However, RMS cells behave differently in 2D culture than in vivo, which has recently inspired the adoption of three-dimensional (3D) culture environments. In the current paper, we will describe the detailed methodology we have developed for fabricating a 3D engineered model to study alveolar RMS (ARMS) in vitro. This model consists of a thermally cross-linked collagen disk laden with RMS cells that mimics the structural and bio-chemical aspects of the tumor extracellular matrix (ECM). This process is highly reproducible and produces a 3D engineered model that can be used to analyze the cytotoxicity and autophagy induction of drugs on ARMS cells. The most improtant bullet points are as following: • We fabricated 3D model of ARMS. • The current ARMS 3D model can be used for screening of chemotherapy drugs. • We developed methods to detect apoptosis and autophagy in ARMS 3D model to detect the mechansims of chemotherapy agents