MicroRNAs targeted mTOR as therapeutic agents to improve radiotherapy outcome.

MicroRNAs (miRNAs) are small RNA molecules that regulate genes and are involved in various biological processes, including cancer development. Researchers have been exploring the potential of miRNAs as therapeutic agents in cancer treatment. Specifically, targeting the mammalian target of the rapamycin (mTOR) pathway with miRNAs has shown promise in improving the effectiveness of radiotherapy (RT), a common cancer treatment. This review provides an overview of the current understanding of miRNAs targeting mTOR as therapeutic agents to enhance RT outcomes in cancer patients. It emphasizes the importance of understanding the specific miRNAs that target mTOR and their impact on radiosensitivity for personalized cancer treatment approaches. The review also discusses the role of mTOR in cell homeostasis, cell proliferation, and immune response, as well as its association with oncogenesis. It highlights the different ways in which miRNAs can potentially affect the mTOR pathway and their implications in immune-related diseases. Preclinical findings suggest that combining mTOR modulators with RT can inhibit tumor growth through anti-angiogenic and anti-vascular effects, but further research and clinical trials are needed to validate the efficacy and safety of using miRNAs targeting mTOR as therapeutic agents in combination with RT. Overall, this review provides a comprehensive understanding of the potential of miRNAs targeting mTOR to enhance RT efficacy in cancer treatment and emphasizes the need for further research to translate these findings into improved clinical outcomes.

Nanofibrous polycaprolactone/gelatin scaffold containing gold nanoparticles: Physicochemical and biological characterization for wound healing.

In this study, gold nanoparticles were loaded into poly (ε-caprolactone) (PCL)/gelatin nanofibrous matrices to fabricate a potential wound dressing. The mats were produced by electrospinning of PCL/gelatin solution supplemented with synthesized gold nanoparticles (200, 400 and 800 ppm). Prepared scaffolds were investigated regarding their chemical properties, morphology, mechanical properties, surface wettability, water-uptake capacity, water vapor permeability, porosity, blood compatibility, microbial penetration test and cellular response. In addition to in vivo study, a full-thickness excisional wound in a rat model was used to evaluate the healing effect of prepared scaffolds. Results showed appropriate mechanical properties and porosity of prepared scaffolds. With L929 cells, the PCL/gelatin scaffold containing 400 ppm gold nanoparticles demonstrated the greatest cell growth. In vivo results validated the favorable wound-healing benefits of the scaffold incorporating gold nanoparticles, which triggered wound healing compared to sterile gauze. Our results showed the capability of nanofibrous matrices containing gold nanoparticles for successful wound treatment.

The Therapeutic Effects of Curcumin-coated Gold Nanoparticle Against Leishmania Major Causative Agent of Zoonotic Cutaneous Leishmaniasis (ZCL): An In Vitro and In Vivo Study.

We synthesized and characterized curcumin-coated gold nanoparticles (Cur@AuNPs) and investigated their stability, cytotoxicity, leishmanicidal activity in in vitro and in in vivo experiments. Cur@AuNPs synthesized through a simple one-pot green chemistry technique. The in vitro leishmanicidal activity of curcumin-coated gold nanoparticles against extracellular promastigotes and intracellular amastigotes of protozoan parasite Leishmania major (L. major) was determined by applying the tetrazolium reduction colorimetric quantitative MTT technique. For in vivo assessment, the footpad lesion size and parasite burden in two infection site organs including lymph nodes and footpads of susceptible BALB/c mice infected with L. major were measured. Mice immune responses in all study groups were quantified by measuring the levels of gamma interferon (IFN-γ) and interleukin-4 (IL-4). Viability of Leishmania promastigotes significantly diminished with the inhibition in promastigotes growth (IC50) of 64.79 µg/mL and 29.89 µg/mL for 24 h and 48 h, respectively. In vitro nanoparticles treatment efficiently cleared the L. major amastigotes explanted in macrophages but had no harmful toxicity on the mice cells. In the in vivo condition, in the treated infected BALB/c mice the CL lesion size, Leishmania parasite burden, and IL-4 were decreased, while IFN-γ was significantly increased. The results suggest that Cur@AuNP was an effective compound against Leishmania parasite in vitro and in vivo, efficiently induced T-helper 1 (Th1) responses and augmented host cellular immune responses, and ending in a reduced Leishmania parasite burden. Therefore, it may be identified as a novel potential therapeutic approach for the local therapy of zoonotic CL treatment with high cure rates.

Synthesis, surface modifications, and biomedical applications of carbon nanofibers: Electrospun vs vapor-grown carbon nanofibers.

Engineered nanostructures are materials with promising properties, enabled by precise design and fabrication, as well as size-dependent effects. Biomedical applications of nanomaterials in disease-specific prevention, diagnosis, treatment, and recovery monitoring require precise, specific, and sophisticated approaches to yield effective and long-lasting favorable outcomes for patients. In this regard, carbon nanofibers (CNFs) have been indentified due to their interesting properties, such as good mechanical strength, high electrical conductivity, and desirable morphological features. Broadly speaking, CNFs can be categorized as vapor-grown carbon nanofibers (VGCNFs) and carbonized CNFs (e.g., electrospun CNFs), which have distinct microstructure, morphologies, and physicochemical properties. In addition to their physicochemical properties, VGCNFs and electrospun CNFs have distinct performances in biomedicine and have their own pros and cons. Indeed, several review papers in the literature have summarized and discussed the different types of CNFs and their performances in the industrial, energy, and composites areas. Crucially however, there is room for a comprehensive review paper dealing with CNFs from a biomedical point of view. The present work therefore, explored various types of CNFs, their fabrication and surface modification methods, and their applications in the different branches of biomedical engineering.

The Functional Roles of Curcumin on Astrocytes in Neurodegenerative Diseases.

Progressive abnormality and loss of axons and neurons in the central nervous system (CNS) cause neurodegenerative diseases (NDs). Protein misfolding and its collection are the most important pathological features of NDs. Astrocytes are the most plentiful cells in the mammalian CNS (about 20-40% of the human brain) and have several central functions in the maintenance of the health and correct function of the CNS. Astrocytes have an essential role in the preservation of brain homeostasis, and it is not surprising that these multifunctional cells have been implicated in the onset and progression of several NDs. Thus, they become an exciting target for the study of NDs. Over almost 15 years, it was revealed that curcumin has several therapeutic effects in a wide variety of diseases' treatment. Curcumin is a valuable ingredient present in turmeric spice and has several essential roles, including those which are anticarcinogenic, hepatoprotective, thrombosuppressive, cardioprotective, anti-arthritic, anti-inflammatory, antioxidant, chemopreventive, chemotherapeutic, and anti-infectious. Furthermore, curcumin can suppress inflammation; promote angiogenesis; and treat diabetes, pulmonary problems, and neurological dysfunction. Here, we review the effects of curcumin on astrocytes in NDs, with a focus on Alzheimer's disease, Parkinson's disease, multiple scleroses, Huntington's disease, and amyotrophic lateral sclerosis.

Plasmonic hyperthermia or radiofrequency electric field hyperthermia of cancerous cells through green-synthesized curcumin-coated gold nanoparticles.

Nanoparticle-mediated hyperthermia is one of the prominent adjuvant therapies which has been faced by many problematic challenges such as efficiency and safety. To compare the nanoparticle-mediated photothermal therapy and radiofrequency electric field hyperthermia, green-synthesized curcumin-coated gold nanoparticles (Cur@AuNPs) were applied in an in vitro study. Using recently published methodologies, each step of the study was performed. Through green chemistry, curcumin was applied as both a reducing and a capping agent in the gold nanoparticle synthesis process. Various techniques were applied for the characterization of the synthesized nanoparticles. The heating rate of Cur@AuNPs in the presence of RFEF or laser irradiation was recorded by using a non-contact thermometer. The cellular uptake of the Cur@AuNPs was studied by ICP-AES. The cellular viability and apoptosis rate of different treatment were measured to investigate the effect of two different nano-hyperthermia techniques on the murine colorectal cancer cell line. The average size of Cur@AuNPs was 7.2 ± 3.3 nm. The stability of the gold nanoparticles in the phosphate buffer saline with and without fetal bovine serum was verified by UV-Vis spectroscopy. FTIR, UV-Vis spectroscopy, and TEM indicate that the stability is a result of phenolic coating on the surface of nanoparticles. Cur@AuNPs can absorb both light and radiofrequency electric field exposure in a way that could kill cancerous cells in a significant number (30% in 64 µg/ml concentration). Green-synthesized Cur@AuNPs could induce apoptosis cell death in photothermal therapy and radiofrequency electric field hyperthermia.

Expression analysis of circulating plasma long noncoding RNAs in colorectal cancer: The relevance of lncRNAs ATB and CCAT1 as potential clinical hallmarks.

Long noncoding RNAs (lncRNAs) have been demonstrated to regulate a variety of cell processes and involve in the development and progression of colorectal cancer (CRC). Recently, the circulating lncRNAs have emerged as minimally invasive biomarkers for cancer diagnosis and prognosis. We aimed to examine the plasma expression level of long noncoding RNAs lnc-ATB, lnc-CCAT1, and lnc-OCC-1 in CRC patients and evaluate the clinical values. A total of 74 pretreatment CRC and 74 healthy blood biopsies were subjected to differentially evaluate the expression levels of three lncRNAs (OCC-1, CCAT1, and ATB). Briefly, after plasma separation and total RNA extraction, RNAs were reversely transcribed to complementary DNA followed by amplification using a quantitative real-time polymerase chain reaction technique for lncRNA expression analysis. The results showed that the expression levels of lnc-ATB (p < 0.001) and CCAT1 (p = 0.024), but not OCC-1 (p = 0.24), were significantly upregulated in the CRC compared with the healthy group. The calculated AUC of ROC was 0.78 (95% confidence interval [CI]: 0.811-0.94) for lnc-ATB and 0.64 (95% CI: 0.811-0.94) for CCAT1, which were indicative of a high discriminatory power (p < 0.001). The highest accuracy for lncRNA-ATB was obtained at a cutoff point of 2.5, which corresponded to sensitivity and specificity of 82% and 75%, respectively. Our results suggested a significant accuracy of lncRNA-ATB and lncRNA-CCAT1 in distinguishing CRC patients from healthy individuals.

Gold nanostructures absorption capacities of various energy forms for thermal therapy applications.

This mini-review has investigated the recent progress regarding gold nanostructures capacities of energy absorption for thermal therapy applications. Unselective thermal therapy of malignant and normal tissues could lead to irreversible damage to healthy tissues without effective treatment on target malignant tissues. In recent years, there has been a considerable progress in the field of cancer thermal therapy for treating target malignant tissues using nanostructures. Due to the remarkable physical properties of the gold nanoparticle, it has been considered as an exceptional element for thermal therapy techniques. Different types of gold nanoparticles have been used as energy absorbent for thermal therapy applications under several types of energy exposures. Electromagnetic, ultrasound, electric and magnetic field are examples for these energy sources. Well-known plasmonic photothermal therapy which applies electromagnetic radiation is under clinical investigation for the treatment of various medical conditions. However, there are many other techniques in this regard which should be explored.

Revolutionizing Cancer Treatment: Harnessing the Power of Mesenchymal Stem Cells for Precise Targeted Therapy in the Tumor Microenvironment.

In recent years, mesenchymal stem cells (MSCs) have emerged as promising anti-- cancer mediators with the potential to treat several cancers. MSCs have been modified to produce anti-proliferative, pro-apoptotic, and anti-angiogenic molecules that could be effective against a variety of malignancies. Additionally, customizing MSCs with cytokines that stimulate pro-tumorigenic immunity or using them as vehicles for traditional chemical molecules with anti-cancer characteristics. Even though the specific function of MSCs in tumors is still challenged, promising outcomes from preclinical investigations of MSC-based gene therapy for a variety of cancers inspire the beginning of clinical trials. In addition, the tumor microenvironment (TME) could have a substantial influence on normal tissue stem cells, which can affect the treatment outcomes. To overcome the complications of TME in cancer development, MSCs could provide some signs of hope for converting TME into unequivocal therapeutic tools. Hence, this review focuses on engineered MSCs (En-MSCs) as a promising approach to overcoming the complications of TME.

Apigenin-coated gold nanoparticles as a cardioprotective strategy against doxorubicin-induced cardiotoxicity in male rats via reducing apoptosis.

Aims: Cardiotoxicity is associated with doxorubicin (DOX), an effective anticancer drug. Apigenin has cardioprotective properties; it may be employed as a capping and reducing agent in synthesizing gold nanoparticles (AuNPs). This study examined the cardioprotective impact of AuNPs synthesized with apigenin (Api) in DOX-induced cardiotoxicity (DIC). Main methods: Api-AuNPs were synthesized in a single pot without needing additional reagents for reducing gold ions or stabilizing the NPs. The cytotoxicity of Api-AuNPs on H9c2 heart cells was subsequently determined using the MTT assay. In the animal investigation, 40 male rats were randomly assigned to one of four groups: control, cardiotoxicity (DOX), DOX treated with apigenin (DOX + Api), or DOX treated with Api-AuNPs (DOX + Api-AuNPs). To examine heart function, echocardiography was conducted. Blood samples were obtained to evaluate injury indicators (Lactate dehydrogenase (LDH), creatine kinase MB (CK-MB), Cardiac Troponin I (cTn-I), Alanine transaminase (ALT), and Aspartate transaminase (AST)). The heart was removed under general anesthetic, weighed, and preserved in formalin solution. Six micrometer-thick cardiac tissue sections were stained with hematoxylin, eosin (H&E), and immunohistochemistry to identify cardiomyocyte apoptotic markers (Bax, Bcl-2, and caspase3). Key findings: Api-AuNPs have an average size of 21.4 ± 11.6 nm and are stable in physiological environments. Api-AuNPs therapy substantially reduced body and heart weight loss compared to the DOX group. Injury indicators were reduced dramatically by Api-AuNPs treatment. Api-AuNPs inhibited myocardial apoptosis via modulating Bax, caspase3, and Bcl-2 and ameliorating tissue damage caused by DOX. Significance: Api-AuNPs' anti-apoptotic activities provide cardioprotection against DIC. It has the potential to reduce cardiotoxicity and boost myocardial performance.

Radiosensitising effect of iron oxide-gold nanocomplex for electron beam therapy of melanoma in vivo by magnetic targeting.

Melanoma is a dangerous type of skin cancer sometimes treated with radiotherapy. However, it induces damage to the surrounding healthy tissue and possibly further away areas. Therefore, it is necessary to give a lower dose to the patient with targeted therapy. In this study, the radio-sensitising effect of gold-coated iron oxide nanoparticles on electron beam radiotherapy of a melanoma tumour with magnetic targeting in a mouse model was investigated. Gold-coated iron oxide nanoparticles were prepared in a steady procedure. The melanoma tumour model was induced in mice. Animals were divided into five groups: (1) normal; (2) melanoma; (3) gold-coated iron oxide nanoparticles alone; (4) electron beam radiotherapy; (5) electron beam radiotherapy plus gold-coated iron oxide nanoparticles. The magnet was placed on the tumour site for 2 h. The tumours were then exposed to 6 MeV electron beam radiotherapy for a dose of 8 Gy. Inductively coupled plasma optical emission spectrometry test, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay blood test were also performed. Gold-coated iron oxide nanoparticles with magnetic targeting before electron beam radiotherapy reduced the growth of the tumour compared to the control group. Blood tests did not show any significant toxicity. Deposition of nanoparticles was more in the tumour and spleen tissue and to a lesser extent in the liver, kidney, and lung tissues. The synergistic effect of nanoparticles administered by the intraperitoneal route and then concentrated into the tumour area by application of an external permanent magnet, before delivery of the electron beam radiotherapy improved the overall cancer treatment outcome and prevented metal distribution side effects.

Gold cluster encapsulated liposomes: theranostic agent with stimulus triggered release capability.

Cancer is a major cause of death worldwide. Cancer-resistant to chemo or radiotherapy treatment is a challenge that could be overcome by a nanotechnology approach. Providing a theranostic nano-platform for different cancer treatment strategies could be revolutionary. Here we introduce a multifunctional theranostic nanostructure which has the capacity for improving cancer diagnosis and treatment through better chemo and radiotherapy and current x-ray imaging systems through co-encapsulation of a small gold cluster and anticancer drug doxorubicin. 2 nm gold clusters represent good heating under radio frequency electric field (RF-EF) exposure and have been used for in vitro hyperthermia treatment of cancerous cells. Liposomal doxorubicin (169 ± 19.8 nm) with gold clusters encapsulation efficiency of 13.2 ± 3.0% and doxorubicin encapsulation efficiency of 64.7 ± 0.7% were prepared and studied as a theranostic agent with a high potential in different cancer treatment modalities. Exposure to a radiofrequency electric field on prepared formulation caused 20.2 ± 2.1% drug release and twice decreasing of IC50 on colorectal carcinoma cells. X-ray attenuation efficiency of the liposomal gold cluster was better than commercial iohexol and free gold clusters in different concentrations. Finally, treatment of gold clusters on cancerous cells results in a significant decrease in the viability of irradiated cells to cobalt-60 beam. Based on these experiments, we concluded that the conventional liposomal formulation of doxorubicin that has been co-encapsulated with small gold clusters could be a suitable theranostic nanostructure for cancer treatment and merits further investigation.

Antifungal activity of green-synthesized curcumin-coated silver nanoparticles alone and in combination with fluconazole and itraconazole against Candida and Aspergillus species.

Background and Purpose: Regarding the wide-spectrum antimicrobial effects of curcumin and silver, this study aimed to evaluate the antifungal activity of green-synthesized curcumin-coated silver nanoparticles (Cur-Ag NPs) against a set of Candida and Aspergillus species. Materials and Methods: Cur-Ag NPs were synthesized by mixing 200 µL of curcumin solution (40 mM) and 15 mL of deionized water. The mixture was stirred for 3-5 min, followed by the addition of 2.5 mL of silver nitrate solution (2.5 mM). The resulting solution was incubated for 3 days. Antifungal susceptibility of 30 fungal isolates of Aspergillus and Candida to fluconazole and itraconazole, as well as the activity of Cur-Ag NPs against the isolates, were determined, both alone and in combination, using broth microdilution according to the Clinical and Laboratory Standards Institute guidelines. Results: Cur-Ag NPs demonstrated promising antifungal activity, particularly against Candida species. The geometric mean value of the minimum inhibitory concentration of Cur-Ag NPs was significantly lower than that of fluconazole for all the studied fungi. Similarly, it was lower than those of itraconazole in C. albicans and A. fumigatus. The minimum fungicidal concentrations of Cur-Ag NPs were markedly better than those of fluconazole but still inferior to those of itraconazole. Conclusion: Cur-Ag NPs demonstrated indisputable antifungal activity and great potential that can be harnessed to combat fungal infections, particularly those caused by azole-resistant strains of Aspergillus and Candida.

Hydrogel nanocomposite based on alginate/zeolite for burn wound healing: In vitro and in vivo study.

Objectives: The main objective of the current assay was to evaluate the antibacterial and regenerative effects of hydrogel nanocomposite containing pure natural zeolite (clinoptilolite) integrated with alginate (Alg) as wound healing/dressing biomaterials. Materials and Methods: The zeolites were size excluded, characterized by SEM, DLS, XRD, FTIR, and XRF, and then integrated into Alg hydrogel followed by calcium chloride crosslinking. The Alg and alginate zeolite (Alg/Zeo) hydrogel was characterized by swelling and weight loss tests, also the antibacterial, hemocompatibility, and cell viability tests were performed. In animal studies, the burn wound was induced on the back of rats and treated with the following groups: control, Alg hydrogel, and Alg/Zeo hydrogel. Results: The results showed that the hydrodynamic diameter of zeolites was 367 ± 0.2 nm. Zeolites did not show any significant antibacterial effect, however, the hydrogel nanocomposite containing zeolite had proper swelling as well as hemocompatibility and no cytotoxicity was observed. Following the creation of a third-degree burn wound on the back of rats, the results indicated that the Alg hydrogel and Alg/Zeo nanocomposite accelerated the wound healing process compared with the control group. Re-epithelialization, granulation tissue thickness, collagenization, inflammatory cell recruitment, and angiogenesis level were not significantly different between Alg and Alg/Zeo nanocomposite. Conclusion: These findings revealed that although the incorporation of zeolites did not induce a significant beneficial effect in comparison with Alg hydrogel, using zeolite capacity in hydrogel for loading the antibiotics or other effective compounds can be considered a promising wound dressing.

Folate functionalized gold-coated magnetic nanoparticles effect in combined electroporation and radiation treatment of HPV-positive oropharyngeal cancer.

The rate of HPV-positive oropharyngeal cancer incidence is increasing, especially in the young population. While these patients show good responses to radiotherapy. The major complication of radiotherapy is normal tissue involvement. Thus, finding an effective treatment method is essential. Multimodal therapy with the lowest side effect could be an effective treatment method. Theranostic gold magnetic core-shell nanostructure was developed as a platform for multimodal therapy of HPV-positive oropharyngeal cancer. The folate functionalized gold-magnetic core-shell nanostructure has been synthesized in a stepwise approach and characterized with various techniques including TEM, UV-Vis, and FTIR spectroscopy. KB was selected as a host for HPV and folate receptor-positive cancer. HGF as normal cell lines was selected. Both cell lines have been treated with nanoparticles, electric field and radiotherapy, either separately or in combination. Cell viability and apoptosis rate were determined by MTT and flow cytometry assay. In addition, cellular uptake of the nanoparticles was measured by ICP-OES analysis. The average size of folate functionalized gold-magnetic core-shell nanostructure was 13.8 ± 6.4 nm. A characteristic plasmonic peak of gold nanoshells was observed in the UV-Vis spectrum. The functionalization of synthesized nanostructure was confirmed with FTIR spectroscopy. None of the treatments alone can cause a significant death in cancerous cells. Combination treatments can increase cancer cell mortality and increase the proportion of apoptotic cells in them. Furthermore, it has been observed that the electric field enhanced the cellular uptake of nanoparticles just in cancerous cells. Based on our findings, we conclude that the combination of folate functionalized nanoparticles and electroporation opens a new way to improve radiation therapy efficacy of HPV-positive cancers.

The application of selenium nanoparticles for enhancing the efficacy of photodynamic inactivation of planktonic communities and the biofilm of Streptococcus mutans.

OBJECTIVE: Streptococcus mutans is one of the principal causative agents of dental caries (tooth decay) found in the oral cavity. Therefore, this study investigates whether selenium nanoparticles (SeNPs) enhance the efficacy of photodynamic therapy (PDT) against both planktonic communities and the one-day-old biofilm of S. mutans. In this study, the planktonic and 24-h biofilm of S. mutans have been prepared in 96-cell microplates. These forms were treated by methylene blue (MB) and SeNPs and then were exposed to light-emitting diode (LED) lighting. Finally, the results have been reported as CFU/ml. RESULTS: The outcomes demonstrated that MB-induced PDT and SeNPs significantly reduced the number of planktonic bacteria (P-value < 0.001). The comparison between the treated and untreated groups showed that combining therapy with SeNPs and PDT remarkably decreased colony-forming units of one-day-old S. mutans biofilm (P-value < 0.05). The findings revealed that PDT modified by SeNPs had a high potential to destroy S. mutans biofilm. This combination therapy showed promising results to overcome oral infection in dental science.

Investigating the in vitro photothermal effect of green synthesized apigenin-coated gold nanoparticle on colorectal carcinoma.

Applying toxic chemical to the synthesis of stable gold nanoparticles is one of the limitations of gold nanoparticles for therapeutic applications such as photothermal therapy. Plant compounds such as apigenin (API) with therapeutic potential can be applied in the synthesis of gold nanoparticles. API-coated gold nanoparticles (Api@AuNPs) with an average size of 19.1 nm and a surface charge of -4.3 mV have been synthesized by a simple and efficient technique. The stability of Api@AuNPs in the biological environment was verified through UV-Vis spectroscopy. Based on Raman and FTIR spectroscopy analysis, chemical binding of API on the surface of Api@AuNPs through hydroxyl and carbonyl functional groups was found to be the main reason for the stability of the Api@AuNPs in comparison with citrate-coated gold nanoparticles (Cit@AuNPs). The synthesized Api@AuNPs do not cause major toxic effects up to 128 ppm. Api@AuNP-mediated photothermal therapy leads to the indiscriminate eradication of almost half of both mouse fibroblastic (L929) and colorectal cancer (CT26) cells. Flow-cytometry analysis revealed that the cell death mechanism is mainly apoptosis. In the apoptosis triggered cell death in photothermal treatment, Api@AuNPs are preferred over commonly used gold nanoparticles in photothermal treatments which mostly trigger the necrosis cell death pathway.

Antimicrobial effects of selenium nanoparticles in combination with photodynamic therapy against Enterococcus faecalis biofilm.

BACKGROUND: Selenium Nanoparticles (SeNPs) were reported as an agent that may enhance the effectiveness of Photodynamic Antimicrobial Chemotherapy (PACT). This in vitro study evaluates the effect of SeNPs on the efficacy of Methylene Blue (MB)-induced PACT against the biofilm formated in 96-well plates and the dentine tubule biofilm of Enterococcus faecalis. METHODS: Chitosan coated SeNPs were synthesized using chemical reduction method and were characterized by Transmission Electron Microscope (TEM) and Dynamic Light Scattering (DLS). Twenty-four-hour biofilms of E. faecalis were developed on 96-well plates and treated with SeNPs, MB, and Light-Emitting Diode (LED). Also, three-week biofilms of E. faecalis were formed on 67 specimens of dentinal tubules, and the antibacterial effects of MB+SeNPs on these biofilms were studied. RESULTS: The average hydrodynamic diameter of SeNPs was 80/3 nm according to DLS measurement. The combined use of MB and SeNPs significantly reduced Colony-Forming Units (CFUs) of one-day-old E. faecalis biofilms in comparison with the control group (P value < 0.05). Besides, combination therapy had the most antibacterial effect on root canal E. faecalis biofilms at both 200 and 400 µm depths of dentine tubules (P value < 0.001). Of note, about 50% of human fibroblast cells survived at a concentration of 128 µg/ml of SeNPs, compared to the control group. CONCLUSION: The results demonstrated that the photodynamic therapy modified by SeNPs could be an effective disinfection alternative to the destruction of E. faecalis biofilms and root canal treatment.

Cross-talk between oxidative stress signaling and microRNA regulatory systems in carcinogenesis: Focused on gastrointestinal cancers.

Molecular mechanisms underlying development and progression of gastrointestinal (GI) cancers are mediated by both oxidative stress (OS) and microRNAs (miRNAs) involvement. Notably, OS signaling may regulate the expression of miRNAs, and miRNAs function as imperative players in OS-initiated tumors. Given the defined biological roles of both OS systems and miRNAs in GI carcinogenesis, a possible interplay between these two key cellular networks is considered. A growing body of evidence has indicated a reciprocal connection between OS signaling pathways and miRNA regulatory machines in GI cancer development and progression. Illumination of the molecular cross-talking between miRNAs and the OS would improve our pathophysiological insight into carcinogens. Also, understanding the molecular mechanisms in which these systems are reciprocally regulated may imply in future medical practice mainly GI cancer therapy. Nowadays, therapeutic strategies focusing on miRNA and OS in GI cancer treatment are increasingly delineated. Since the use of antioxidants is limited owing to the contrasting consequences of OS signaling in cancer, the discovery of OS-responsive miRNAs may provide a potential new strategy to overcome OS-mediated GI carcinogenesis. Given the possible interaction between OS and miRNAs in GI cancers, this review aimed to elucidate the existing evidence on the interaction between OS and miRNA regulatory machinery and its role in GI carcinogenesis. In this regard, we will illustrate the function of miRNAs which target OS systems during homeostasis and tumorigenesis. We also discuss the biological cross-talk between OS systems and miRNAs and corresponding cell signaling pathways.

Preparation of antimicrobial metallic nanoparticles with bioactive compounds.

Despite the all recent advancements in medicine, infectious diseases continue to be major causes of death worldwide. Developing nanomaterials as preventive and therapeutic agents against infectious diseases has been one of the research priorities in medicine. However, the application of metal nanoparticles as antimicrobial agents is hampered due to environmental and safety concerns. Using green chemistry, researchers can produce biocompatible nanoparticles that have fewer detrimental effects on human health and the environment. Although chemical compounds have been considered as traditional sources for producing nanomaterials, a wide variety of biocompatible plant-derived secondary metabolites have recently been introduced that can be used to synthesize and stabilize metal nanoparticles. These metabolites have shown potent antibacterial effects making them suitable substitutes for the chemical agents in nanoparticle synthesis. This review has focused on the antimicrobial properties of metal nanoparticles synthesized using plant-derived secondary metabolites instead of crude extract. The mechanisms of metal nanoparticles synthesis and antimicrobial activity are also discussed for different phytochemicals and metal nanoparticles. Finally, the evaluation of the toxicity and safety of phytochemicals coated metal nanoparticles has been conducted. I believe that this is the first review on the antimicrobial and other biological properties of metal nanoparticles synthesized or coated utilizing specific plant-derived secondary metabolites.