Application of CRISPR-Cas9 genome editing system in biomedical studies: recent progress and future perspectives

Introduction: Recent advances in genome engineering are starting a revolution in biological research. The clustered regularly interspaced short palindromic repeats (CRISPR) and its associated protein (Cas9) enables diverse manipulations of genome function. It has become a predictable and precise method of choice for genome engineering by specifying a 20-nt targeting sequence within its guide RNA. Regarding its simplicity, broad applicability, and high efficiency, CRISPR-Cas9 tool can be used in understanding of cellular mechanisms, generating animal models, correcting defective gene(s) causing diseases, cancer treatment, removal of bacterial/ viral infections, and in drug discovery. Moreover, the capability of CRISPRi to gene regulation without altering its function can be utilized for exceeding our knowledge of gene expression in prokaryotic and eukaryotic systems. Results: In this lecture, the history and biology of CRISPR system were described firstly. Also, the applications of CRISPR-Cas9 in various ways, such as efficient generation of a wide variety of biomedical important cellular models as well as animal ones, modifying epigenomes, conducting genome-wide screens, labeling specific genomic loci in living cells, genome editing applications in xenotransplantation and endogenous gene expression regulation by an altered version of this system were reviewed. Moreover, we describe how this technology can be used as an antimicrobial or antiviral tool. However, this technology still needs optimization and will require a better understanding of how this system works on molecular level. Conclusions: The broad applications of CRISPR-Cas9 technology in biological research will greatly advance our knowledge of basic biology as well as opening a door to treat a wide spectrum of human diseases

Penicillium chrysogenum-Derived Silver Nanoparticles: Explorationof Their Antibacterial and Biofilm Inhibitory Activity Againstthe Standard and Pathogenic Acinetobacter baumannii Compared to Tetracycline

Abstract: This study was aimed to evaluate the antibacterial and biofilm inhibitory activity of Penicillium chrysogenum-derivedsilver nanoparticles (AgNPs) against the standard and pathogenic Acinetobacter baumannii using a 96-well microtiterplate-based method. The AgNPs were characterized by using UV–Vis, TEM, AFM, XRD, DLS, Zeta potential, and FT-IR.The nanoparticles (NPs) were fabricated with a spherical shape and an average hydrodynamic diameter of 48.2 nm. Theminimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNPs were found to be 4and 32 lg/mL respectively, whereas the MIC and MBC of tetracycline were found to be 1024 and 8192 lg/mL against A.baumannii (ATCC 19606). The AgNPs and tetracycline represented considerable biofilm inhibitory activity against boththe standard and pathogenic A. baumannii at the studied concentrations. However, the AgNPs depicted higher potency toinhibit the process of biofilm formation of some pathogenic A. baumannii species compared to tetracycline. The AgNPs atthe concentration of 0.5*MIC (2 lg/mL) inhibited above 90% biofilm inhibition, whereas tetracycline reached 90% biofilminhibition at the concentration of 4*MIC (4096 lg/mL) against A. baumannii (ATCC 19606). However, further studies arerequired to evaluate the biofilm inhibitory efficacy of biogenic AgNPs in vivo. Keywords: Silver nanoparticles, Biosynthesis, Antibacterial activity, Biofilm inhibitory activit

A Systematic Review of the Genotoxicity and Antigenotoxicity of Biologically Synthesized Metallic Nanomaterials: Are Green Nanoparticles Safe Enough for Clinical Marketing?

Abstract: Background and objectives: Although studies have elucidated the significant biomedical potential of biogenic metallic nanoparticles (MNPs), it is very important to explore the hazards associated with the use of biogenic MNPs. Evidence indicates that genetic toxicity causes mutation, carcinogenesis, and cell death. Materials and Methods: Therefore, we systematically review original studies that investigated the genotoxic effect of biologically synthesized MNPs via in vitro and in vivo models. Articles were systematically collected by screening the literature published online in the following databases; Cochrane, Web of Science, PubMed, Scopus, Science Direct, ProQuest, and EBSCO. Results: Most of the studies were carried out on the MCF-7 cancer cell line and phytosynthesis was the general approach to MNP preparation in all studies. Fungi were the second most predominant resource applied for MNP synthesis. A total of 80.57% of the studies synthesized biogenic MNPs with sizes below 50 nm. The genotoxicity of Ag, Au, ZnO, TiO2, Se, Cu, Pt, Zn, Ag-Au, CdS, Fe3O4, Tb2O3, and Si-Ag NPs was evaluated. AgNPs, prepared in 68.79% of studies, and AuNPs, prepared in 12.76%, were the two most predominant biogenic MNPs synthesized and evaluated in the included articles. Conclusions: Although several studies reported the antigenotoxic influence of biogenic MNPs, most of them reported biogenic MNP genotoxicity at specific concentrations and with a dose or time dependence. To the best of our knowledge, this is the first study to systematically evaluate the genotoxicity of biologically synthesized MNPs and provide a valuable summary of genotoxicity data. In conclusion, our study implied that the genotoxicity of biologically synthesized MNPs varies case-by-case and highly dependent on the synthesis parameters, biological source, applied assay, etc. The gathered data are required for the translation of these nanoproducts from research laboratories to the clinical market. Keywords: genotoxicity; biosynthesis; metal nanoparticles; systematic revie

Nanomaterials to aid wound healing and infection control

The management and treatment of infectious bacterial diseases in wound healing have both become significant research areas in the biomedical field. While current treatments show limitations related to toxicity and exposure time, nanotechnology has become a potential alternative to overcome such challenges. The application of different nanomaterials, with a wide range of elemental compositions, morphologies, and features, has become an essential tool in managing wound healing infections. This book chapter shows an updated view of the newest trends in the control and treatment of bacterial proliferation in the wound bed by utilizing various metal- and nonmetal-based nanostructures

Biofabrication of gold and silver nanoparticles for pharmaceutical applications

Biofabrication by using fungi is an exciting recent interest to develop an eco-friendly production of metallic nanoparticles (NPs) for pharmaceutical applications. This study aimed to synthesize and characterize gold (Au) and silver (Ag) NPs by using Penicillium simplisimum. The fungus was grown in fluid czapek dox broth on shaker at 28 ºC and 200 rpm for ten days. Then the supernatant was separated from the mycelia to convert HAuCl4 and AgNO3 solution into Au and Ag NPs separately. After 24 hours, synthesized Au and Ag NPs were characterized by using UV-Visible Spectroscopy as well as Photon Correlation spectroscopy (PCS) involves Polydispersity Index (PDI) and zeta potential. The UV-Visible Spectroscopy analysis revealed a plasmon bond peak around 533 nm and 400 nm suggesting formation of Au and Ag NPs, respectively. Furthermore, the PCS analysis showed an average diameter of 68 nm and 76 nm with PDI value of 0.2 and 0.23 for Au and Ag NPs, successively, which demonstrated that the nanoparticles formed with fairly well-defined dimensions and good monodispersity. Besides, a negative zeta potential were found for nanoparticles indicating their stability in the solution. The current approach suggests that the rapid synthesis of nanoparticles would be suitable for developing a green process for mass scale production. Besides, we believe that development of eco-friendly process for the formulation of metallic NPs is an important step in the field of application of nanotechnology and its optimization may make it a potential procedure for industrial production of NPs

Green Synthesis of Silver Nanoparticles Induced by the Fungus Penicillium citrinum

Purpose: To evaluate a green process for the extracellular production of silver (Ag) nanoparticles synthesized and stabilized using Penicillium citrinum isolated from soil. Methods: The pure colonies of Penicillium citrinum were cultured in Czapek dox broth. The supernatant of the broth was examined for the ability to produce silver nanoparticles. The reactions were performed in a dark compartment at 28 ºC. After 24 h, the synthesized silver nanoparticles were filtered through a membrane filter (0.45 μ) and characterized by UV-visible spectroscopy, fluorescence spectroscopy, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR) for particle size, shape and the presence of different functional groups in the nanoparticles. Results: The silver nanoparticles formed were fairly uniform in size with a spherical shape and a Zaverage diameter of 109 nm. FTIR spectra revealed the presence of amide linkage groups which were also found in the fungal extract itself. Conclusion: The current approach suggests that rapid synthesis of nanoparticles of silver nitrate would be suitable for developing a biological process for mass scale production of formulations

Anti-cancer green bionanomaterials: present status and future prospects

Cancer is one of the most common health problems responsible for outnumbered deaths worldwide. Nanomedicine plays an important role in developing alternative and more effective treatment strategies for cancer theranostics. However, the toxicity, high cost and nanoparticles (NPs) production complexity are some of the major issues that obstruct the use of existing nanomedicine. Recently, the green synthesis of biogenic NPs from plants and microbial sources has become an emerging field due to their safer, eco-friendly, simple, fast, energy efficient, low-cost and less toxic nature. Interestingly, NPs play a key role in diagnosis of tumor at the initial stage by allowing cellular visualization. Furthermore, prospective applications of green NPs include magnetically responsive drug delivery, anti-cancer activity, photo-thermal therapy and bio-imaging. The present review provides perspective on the use of anti-cancer green bionanomaterials with a focus on their present status and future prospects in the theranostics of cancer

Green Synthesis of Silver Nanoparticles Induced by the Fungus Penicillium citrinum

Purpose: To evaluate a green process for the extracellular production of silver (Ag) nanoparticles synthesized and stabilized using Penicillium citrinum isolated from soil. Methods: The pure colonies of Penicillium citrinum were cultured in Czapek dox broth. The supernatant of the broth was examined for the ability to produce silver nanoparticles. The reactions were performed in a dark compartment at 28 ºC. After 24 h, the synthesized silver nanoparticles were filtered through a membrane filter (0.45 μ) and characterized by UV-visible spectroscopy, fluorescence spectroscopy, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR) for particle size, shape and the presence of different functional groups in the nanoparticles. Results: The silver nanoparticles formed were fairly uniform in size with a spherical shape and a Zaverage diameter of 109 nm. FTIR spectra revealed the presence of amide linkage groups which were also found in the fungal extract itself. Conclusion: The current approach suggests that rapid synthesis of nanoparticles of silver nitrate would be suitable for developing a biological process for mass scale production of formulations

Trachyspermum copticum aqueous seed extract-derived silver nanoparticles: Exploration of their structural characterization and comparative antibacterial performance against gram-positive and gram-negative bacteria

In this study, the aqueous seed extract of Trachyspermum copticum was employed to fabricate silver nanoparticles (AgNPs) for their antibacterial performance. The structural characteristics of the phytofabricated AgNPs were investigated using ultraviolet–visible, energy dispersive X-ray, dynamic light scattering, zeta potential, field emission scanning electron microscope, and Fourier transform infrared spectroscopy. Further, the antibacterial effects of AgNPs were evaluated against two standard gram-positive strains of Staphylococcus aureus and Streptococcus pyogenes and two standard gram-negative strains of Escherichia coli and Klebsiella pneumoniae. The findings showed the phytofabrication of spherical-shaped AgNPs with a Z-average diameter of 119.7 nm and the polydispersity index of 0.56. The minimum inhibitory concentration of AgNPs against S. aureus, S. pyogenes, E. coli, and K. pneumoniae strains was 0.25, 1, 0.5, and 0.5 μg·mL−1, respectively. In addition, the minimum bactericidal concentration of these nanoparticles (NPs) against the mentioned strains was 8, 16, 4, and 4 μg·mL−1, respectively. Furthermore, the AgNPs enhanced the generation of reactive oxygen species significantly in all studied bacteria compared to the control (P < 0.05) suggesting an oxidative-associated antibacterial mechanism of AgNPs. Moreover, a dose-dependent cell death was found in all bacterial samples based on flow cytometry analysis. Overall, this study showed a biological approach for the biosynthesis of AgNPs with significant antibacterial effects