Gold nanoparticles and electroporation impose both separate and synergistic radiosensitizing effects in HT-29 tumor cells: an in vitro study

Recent Insights into Nanotechnology in Colorectal Cancer

Colorectal cancer (CRC) is the third cancer among the known causes of cancer that impact people. Although CRC drug options are imperfect, primary detection of CRC can play a key role in treating the disease and reducing mortality. Cancer tissues show many molecular markers that can be used as a new way to advance therapeutic methods. Nanotechnology includes a wide range of nanomaterials with high diagnostic and therapeutic power. Several nanomaterials and nanoformulations can be used to treat cancer, especially CRC. In this review, we discuss recent insights into nanotechnology in colorectal cancer.

Improving NonViral Gene Delivery Using MHz Bursts of Nanosecond Pulses and Gold Nanoparticles for Electric Field Amplification

Gene delivery by the pulsed electric field is a promising alternative technology for nonviral transfection; however, the application of short pulses (i.e., nanosecond) is extremely limited. In this work, we aimed to show the capability to improve gene delivery using MHz frequency bursts of nanosecond pulses and characterize the potential use of gold nanoparticles (AuNPs: 9, 13, 14, and 22 nm) in this context. We have used bursts of MHz pulses 3/5/7 kV/cm × 300 ns × 100 and compared the efficacy of the parametric protocols to conventional microsecond protocols (100 µs × 8, 1 Hz) separately and in combination with nanoparticles. Furthermore, the effects of pulses and AuNPs on the generation of reactive oxygen species (ROS) were analyzed. It was shown that gene delivery using microsecond protocols could be significantly improved with AuNPs; however, the efficacy is strongly dependent on the surface charge of AuNPs and their size. The capability of local field amplification using AuNPs was also confirmed by finite element method simulation. Finally, it was shown that AuNPs are not effective with nanosecond protocols. However, MHz protocols are still competitive in the context of gene delivery, resulting in low ROS generation, preserved viability, and easier procedure to trigger comparable efficacy.

Enhanced Therapeutic Potential of Irreversible Electroporation under Combination with Gold-Doped Mesoporous Silica Nanoparticles against EMT-6 Breast Cancer Cells

Irreversible electroporation (IRE) is a non-thermal tumor ablation technique that delivers short pulses of strong electric fields to cancer tissues and induces cell death through the destruction of cell membranes. Here, we synthesized gold-doped mesoporous silica nanoparticles (Au-MSNs) via incipient wetness impregnation and evaluated the therapeutic potentials of combination therapy with IRE. The fabricated Au-MSNs had around 80-100 nm of particle size and were successfully end-doped with Au nanoparticles. Combination treatment of IRE (800 V/cm) and Au-MSNs (100 μg/mL) increased cell membrane permeability by 25-fold compared with single IRE treatment. Cellular reactive oxygen species (ROS) and lipid peroxidation of EMT-6 cells were significantly increased by 14- and 265-fold, respectively, under combination treatment of IRE (800 V/cm) and Au-MSNs (100 µg/mL). Cytotoxic cell death increased by 28% under a combination treatment of IRE (800 V/cm) and Au-MSNs (100 ug/mL) over single IRE. Our studies suggest that the combination treatment of IRE with Au-MSNs can enhance the therapeutic efficacy of IRE for breast cancer.

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 Emerging Role of Ultrasonic Nanotechnology for Diagnosing and Treatment of Diseases

Nanotechnology has been commonly used in a variety of applications in recent years. Nanomedicine has also gotten a lot of attention in the medical and treatment fields. Ultrasonic technology is already being used in research as a powerful tool for manufacturing nonmaterial and in the decoration of catalyst supports for energy applications and material processing. For the development of nanoparticles and the decoration of catalytic assisted powders with nanoparticles, low or high-frequency Ultrasonic are used. The Ultrasonic is frequently used in joint venture with the nanotechnology from the past few years and bring tremendous success in various diseases diagnosing and treatment. Numerous kinds of nanoparticles are fabricated with desired capabilities and targeted toward different targets. This review first highlights the Ultrasonic Treatment and processing of Nanoparticles for Pharmaceuticals. Next, we explain various nanoparticles with ultrasonic technology for different diagnosing and treatment of various diseases. Finally, we explain the challenges face by current approaches for their translation in clinics.

Gold Nanoparticle Drug Delivery System: Principle and Application

In recent years, gold nanoparticles (GNPs) have gradually become a major choice of drug delivery cargoes due to unique properties. Compared to traditional bulk solid gold, GNPs have basic physical and chemical advantages, such as a larger surface area-to-volume ratio and easier surface modification. Furthermore, these have excellent biocompatibility, can induce the directional adsorption and enrichment of biological macromolecules, help retain biological macromolecule activity, and cause low harm to the human body. All these make GNPs good drug delivery cargoes. The present study introduces the properties of GNPs, including factors that affect the properties and synthesis. Then, focus was given on the application in drug delivery, not only on the molecular mechanism, but also on the clinical application. Furthermore, the properties and applications of peptide GNPs were also introduced. Finally, the challenges and prospects of GNPs for drug delivery were summarized.

Matrix Metalloproteinases (MMPs) in Targeted Drug Delivery: Synthesis of a Potent and Highly Selective Inhibitor against Matrix Metalloproteinase- 7

BACKGROUND

Matrix metalloproteinases (MMPs) are a family of zinc endopeptidases that play a key role in both physiological and pathological tissue degradation. MMPs have reportedly shown great potentials in the degradation of the Extracellular Matrix (ECM), have shown great potentials in targeting bioactive and imaging agents in cancer treatment. MMPs could provoke Epithelial to Mesenchymal Transition (EMT) of cancer cells and manipulate their signaling, adhesion, migration and invasion to promote cancer cell aggressiveness. Therefore, targeting and particularly inhibiting MMPs within the tumor microenvironment is an effective strategy for cancer treatment. Based on this idea, different MMP inhibitors (MMPIs) have been developed to manipulate the tumor microenvironment towards conditions appropriate for the actions of antitumor agents. Studies are ongoing to improve the selectivity and specificity of MMPIs. Structural optimization has facilitated the discovery of selective inhibitors of the MMPs. However, so far no selective inhibitor for MMP-7 has been proposed.

AIMS

This study aims to comprehensively review the potentials and advances in applications of MMPs particularly MMP-7 in targeted cancer treatment approaches with the main focus on targeted drug delivery. Different targeting strategies for manipulating and inhibiting MMPs for the treatment of cancer are discussed. MMPs are upregulated at all stages of expression in cancers. Different MMP subtypes have shown significant targeting applicability at the genetic, protein, and activity levels in both physiological and pathophysiological conditions in a variety of cancers. The expression of MMPs significantly increases at advanced cancer stages, which can be used for controlled release in cancers in advance stages.

METHODS

Moreover, this study presents the synthesis and characteristics of a new and highly selective inhibitor against MMP-7 and discusses its applications in targeted drug delivery systems for therapeutics and diagnostics modalities.

RESULTS

Our findings showed that the structure of the inhibitor P3' side chains play the crucial role in developing an optimized MMP-7 inhibitor with high selectivity and significant degradation activities against ECM.

CONCLUSION

Optimized NDC can serve as a highly potent and selective inhibitor against MMP-7 following screening and optimization of the P3' side chains, with a Ki of 38.6 nM and an inhibitory selectivity of 575 of MMP-7 over MMP-1.

Membrane Derived Vesicles as Biomimetic Carriers for Targeted Drug Delivery System

Extracellular vesicles (EVs) are membrane vesicles (MVs) playing important roles in various cellular and molecular functions in cell-to-cell signaling and transmitting molecular signals to adjacent as well as distant cells. The preserved cell membrane characteristics in MVs derived from live cells, give them great potential in biological applications. EVs are nanoscale particulates secreted from living cells and play crucial roles in several important cellular functions both in physiological and pathological states. EVs are the main elements in intercellular communication in which they serve as carriers for various endogenous cargo molecules, such as RNAs, proteins, carbohydrates, and lipids. High tissue tropism capacity that can be conveniently mediated by surface molecules, such as integrins and glycans, is a unique feature of EVs that makes them interesting candidates for targeted drug delivery systems. The cell-derived giant MVs have been exploited as vehicles for delivery of various anticancer agents and imaging probes and for implementing combinational phototherapy for targeted cancer treatment. Giant MVs can efficiently encapsulate therapeutic drugs and deliver them to target cells through the membrane fusion process to synergize photodynamic/photothermal treatment under light exposure. EVs can load diagnostic or therapeutic agents using different encapsulation or conjugation methods. Moreover, to prolong the blood circulation and enhance the targeting of the loaded agents, a variety of modification strategies can be exploited. This paper reviews the EVs-based drug delivery strategies in cancer therapy. Biological, pharmacokinetics and physicochemical characteristics, isolation techniques, engineering, and drug loading strategies of EVs are discussed. The recent preclinical and clinical progresses in applications of EVs and oncolytic virus therapy based on EVs, the clinical challenges and perspectives are discussed.

Glycyrrhetinic Acid and TAT Peptide Modified Dual-functional Liposomes for Treatment of Hepatocellular Cancer

BACKGROUND

Surgery remains the front-line therapeutic strategy to treat early hepatocellular carcinoma (HCC). However, the 5-year recurrence rates of HCC patients are high. 10- Hydroxycamptothecin (10-HCPT) is a known anti-HCC agent but its poor solubility and bioavailability have limited its clinical use.

OBJECTIVE

In this study, we developed a novel nanoliposome encapsulated 10-hydroxycamptothecin modified with glycyrrhetinic acid (GA) and TAT peptide (GA/TAT-HCPT-LP) for the treatment of HCC. Dual modified GA and TAT can enhance tumor targeting and tumor penetration.

METHODS

The GA/TAT-HCPT-LP NPs were synthesized using the thin-film dispersion method. GA/TAT-HCPT-LP were characterized for particle size, zeta potential and morphology. Drug release from the GA/TAT-HCPT-LP liposomes was measured by dialysis. Cell-uptake was assessed by microscopy and flow cytometry. Cell proliferation, migration and apoptosis were measured to evaluate in vitro antitumor activity of GA/TAT-HCPT-LP via CCK-8 assays, Transwell assays, and flow cytometry, respectively. The in vivo distribution of GA/TAT-HCPT-LP was evaluated in HCC animal models. Tumor- bearing mouse models were used to assess the in vivo therapeutic efficacy of GA/TAT-HCPT-LP.

RESULTS

The mean particle size and mean zeta potential of GA/TAT-HCPT-LP were 135.55 ± 2.76 nm and -4.57 ± 0.23 mV, respectively. Transmission electron micrographs (TEM) showed that the GA/TAT-HCPT-LP had a near spherical shape and a double-membrane structure. GA/TAT-HCPT-LP led to slow and continuous drug release, and could bind to HepG2 cells more readily than other groups. Compared to control groups, treatment with GA/TAT-HCPT-LP had a significantly large effect on inhibiting cell proliferation, tumor cell migration and cell apoptosis. In vivo assays showed that GA/TATHCPT- LP selectively accumulated in tumor tissue with obvious antitumor efficacy.

CONCLUSION

In conclusion, the synthesized GA/TAT-HCPT-LP could effectively target tumor cells and enhance cell penetration, highlighting its potential for hepatocellular cancer therapy.

Cellular and Molecular Targeted Drug Delivery in Central Nervous System Cancers: Advances in Targeting Strategies

Central nervous system (CNS) cancers are among the most common and treatment-resistant diseases. The main reason for the low treatment efficiency of the disorders is the barriers against targeted delivery of anticancer agents to the site of interest, including the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB). BBB is a strong biological barrier separating circulating blood from brain extracellular fluid that selectively and actively prevents cytotoxic agents and majority of anticancer drugs from entering the brain. BBB and BBTB are the major impediments against targeted drug delivery into CNS tumors. Nanotechnology and its allied modalities offer interesting and effective delivery strategies to transport drugs across BBB to reach brain tissue. Integrating anticancer drugs into different nanocarriers improves the delivery performance of the resultant compounds across BBB. Surface engineering of nanovehicles using specific ligands, antibodies and proteins enhances the BBB crossing efficacy as well as selective and specific targeting to the target cancerous tissues in CNS tumors. Multifunctional nanoparticles (NPs) have brought revolutionary advances in targeted drug delivery to brain tumors. This study reviews the main anatomical, physiological and biological features of BBB and BBTB in drug delivery and the recent advances in targeting strategies in NPs-based drug delivery for CNS tumors. Moreover, we discuss advances in using specific ligands, antibodies, and surface proteins for designing and engineering of nanocarriers for targeted delivery of anticancer drugs to CNS tumors. Finally, the current clinical applications and the perspectives in the targeted delivery of therapeutic molecules and genes to CNS tumors are discussed.

Trends in targeted delivery of nanomaterials in colon cancer diagnosis and treatment

Colon cancer is an adenocarcinoma, which subsequently develops into malignant tumors, if not treated properly. The current colon cancer therapy mainly revolves around chemotherapy, radiotherapy and surgery, but the search continues for more effective interventions. With the advancement of nanoparticles (NPs), it is now possible to diagnose and treat colon cancers with different types, shapes, and sizes of NPs. Nanoformulations such as quantum dots, iron oxide, polymeric NPs, dendrimers, polypeptides, gold NPs, silver NPs, platinum NPs, and cerium oxide have been either extensively used alone or in combination with other nanomaterials or drugs in colon cancer diagnosis, and treatments. These nanoformulations possess high biocompatibility and bioavailability, which makes them the most suitable candidates for cancer treatment. The size and shape of NPs are critical to achieving an effective drug delivery in cancer treatment and diagnosis. Most NPs currently are under different testing phases (in vitro, preclinical, and clinical), whereas some of them have been approved for therapeutic applications. We have comprehensively reviewed the recent advances in the applications of NPs-based formulations in colon cancer diagnosis and treatment.

Pien Tze Huang (PZH) as a Multifunction Medicinal Agent in Traditional Chinese Medicine (TCM): a review on cellular, molecular and physiological mechanisms

RELEVANCE

Pien Tze Huang (PZH) is a well-known Traditional Chinese Medicine (TCM), characterized by a multitude of pharmacological effects, such as hepatoprotection and inhibition of inflammation and cell proliferative conditions. Many of these effects have been validated at the cellular, molecular and physiological levels but, to date, most of these findings have not been comprehensively disclosed.

OBJECTIVES

This review aims to provide a critical summary of recent studies focusing on PZH and its multiple pharmacological effects. As a result, we further discuss some novel perspectives related to PZH's mechanisms of action and a holistic view of its therapeutic activities.

METHODS

A systematic review was performed focusing on PZH studies originated from original scientific resources. The scientific literature retrieved for this work was obtained from International repositories including NCBI/PubMed, Web of Science, Science Direct and China National Knowledge Infrastructure (CNKI) databases.

RESULTS

The major active componentes and their potential functions, including hepatoprotective and neuroprotective effects, as well as anti-cancer and anti-inflammatory activities, were summarized and categorized accordingly. As indicated, most of the pharmacological effects were validated in vitro and in vivo. The identification of complex bioactive components in PZH may provide the basis for further therapeutic initiatives.

CONCLUSION

Here we have collectively discussed the recent evidences covering most, if not all, pharmacological effects driven by PZH. This review provides novel perspectives on understanding the modes of action and the holistic view of TCM. The rational development of future clinical trials will certainly provide evidence-based medical evidences that will also confirm the therapeutic advantages of PZH, based on the current information available.

Radiation-Induced Sarcoma of the Head and Neck Following Radiotherapy for Nasopharyngeal Carcinoma: A Single Institutional Experience and Literature Review

Background and Objective

Radiotherapy (RT) is the primary treatment option for nasopharyngeal carcinoma (NPC), but it is associated with radiation-induced sarcomas (RISs). This study aims to investigate clinicopathological features and head and neck RIS prognosis after NPC RT.

Methods

The medical and radiological records of the NPC patients (n =14,074) referred to Zhejiang Cancer Hospital, Hang Zhou, China between January 1995 and December 2018 were retrospectively reviewed. Among them, 22 patients were determined to have RIS after RT for NPC. The clinicopathological data, diagnosis, treatment, and follow-up results of 22 patients with RIS were analyzed in this retrospective research. All 22 patients underwent surgery as the main treatment. The levels of Overall Survival (OS) were determined through the Log-rank test and Kaplan-Meier method.

Results

Among these patients, 13 were males and nine females with the male/female ratio of 1.44:1. The age during the primary RT of NPC ranged from 25 to 61 years old (median age: 37 years old). Patients' ages ranged from 33 to 73 years old (median age: 52.5 years old) when diagnosed with RIS. The latency period for development of the RIS was between 3 and 36 years (median: 8.5 years) after RT. In this cohort, R0 resection was achieved in 13 cases, R1 resection in five cases, and R2 resection in four cases. During the follow-up period ranged from 2 to 102 months (median 14 months), 15 patients had died of the disease. Kaplan-Meier method showed that the 2-year, 3-year, and the 5-year cumulative OS rate was 50.3, 43.2, and 14.4%, respectively. The median survival time was 34 months. Surgical resection with R0 resection achieves a significantly better prognosis (P = 0.012). Patients under the age of 37 years old at the time of initial RT had a relatively better prognosis (P = 0.035).

Conclusions

Although the incidence of RIS after RT of NPC is generally low, the treatment of RIS is very difficult. The RISs are associated with poor overall prognosis. R0 resection can improve the prognosis thus it should be considered as the primary and optimal choice for the treatment of RIS.

Quantitative Structure-activity Relationships; Studying the Toxicity of Metal Nanoparticles

Background:

Metal nanomaterials are widely used in various fields, including targeted therapy and diagnosis. They are extensively used in targeted drug delivery and local treatments. However, the toxicity associated with these materials could lead to severe adverse health effects.

Methods:

In this study, we investigated the relationships between the toxicity and structures of metal nanoparticles by using theoretical calculations and quantitative structure-activity relationships. Twenty four physicochemical descriptors and toxicity data of 23 types of metal nanoparticles were selected as samples, and a multiple linear regression model was established to obtain a toxicity prediction equation with 5 descriptors with an R2 of 0.910. Structures of copper nanoparticles were designed based on the model, and the structure with low toxicity was searched. The multiple nonlinear regression model was used to further improve the prediction accuracy.

Results:

The R2 values were 0.995 in the training set and 0.988 in the test set, which indicated that the prediction accuracy improved. Based on the result of multiple linear regression, we designed copper nanoparticles with low toxicity.

Conclusion:

The study confirmed that the quantitative structure-activity relationship was a reasonable method for predicting the toxicity and designing the structures with low toxicity of metal nanoparticles.

Main Approaches to Enhance Radiosensitization in Cancer Cells by Nanoparticles: A Systematic Review

In recent years, high atomic number nanoparticles (NPs) have emerged as promising radio-enhancer agents for cancer radiation therapy due to their unique properties. Multi-disciplinary studies have demonstrated the potential of NPs-based radio-sensitizers to improve cancer therapy and tumor control at cellular and molecular levels. However, studies have shown that the dose enhancement effect of the NPs depends on the beam energy, NPs type, NPs size, NPs concentration, cell lines, and NPs delivery system. It has been believed that radiation dose enhancement of NPs is due to the three main mechanisms, but the results of some simulation studies failed to comply well with the experimental findings. Thus, this study aimed to quantitatively evaluate the physical, chemical, and biological factors of the NPs. An organized search of PubMed/Medline, Embase, ProQuest, Scopus, Cochrane and Google Scholar was performed. In total, 77 articles were thoroughly reviewed and analyzed. The studies investigated 44 different cell lines through 70 in-vitro and 4 in-vivo studies. A total of 32 different types of single or core-shell NPs in different sizes and concentrations have been used in the studies.

Chemical Mechanisms of Nanoparticle Radiosensitization and Radioprotection: A Review of Structure-Function Relationships Influencing Reactive Oxygen Species

Metal nanoparticles are of increasing interest with respect to radiosensitization. The physical mechanisms of dose enhancement from X-rays interacting with nanoparticles has been well described theoretically, however have been insufficient in adequately explaining radiobiological response. Further confounding experimental observations is examples of radioprotection. Consequently, other mechanisms have gained increasing attention, especially via enhanced production of reactive oxygen species (ROS) leading to chemical-based mechanisms. Despite the large number of variables differing between published studies, a consensus identifies ROS-related mechanisms as being of significant importance. Understanding the structure-function relationship in enhancing ROS generation will guide optimization of metal nanoparticle radiosensitisers with respect to maximizing oxidative damage to cancer cells. This review highlights the physico-chemical mechanisms involved in enhancing ROS, commonly used assays and experimental considerations, variables involved in enhancing ROS generation and damage to cells and identifies current gaps in the literature that deserve attention. ROS generation and the radiobiological effects are shown to be highly complex with respect to nanoparticle physico-chemical properties and their fate within cells. There are a number of potential biological targets impacted by enhancing, or scavenging, ROS which add significant complexity to directly linking specific nanoparticle properties to a macroscale radiobiological result.

Free Radical Scavenging and Some Pharmaceutical Utilities of Nanoparticles in the Recent Scenario

BACKGROUND

Nanopharmaceuticals have rapidly emerged as a means to cure several diseases. There are numerous reports describing the development and application of nanopharmaceuticals. Here, we discussed nanoparticle synthesis and the mechanisms to scavenge free radicals. We also discuss their major properties and list several commercially available nanomedicines.

RESULTS

Reactive oxygen and hydrogen species are formed during normal metabolism, and excessive reactive species can damage proteins, lipids, and DNA and cause disease. Plant- and microbe-based nanoparticles, which can protect tissues from free radical damage, have recently gained research momentum because they are inexpensive and safe.

CONCLUSION

Synthetic and biocompatible nanoparticles exhibit antioxidant, antidiabetic, anti-inflammatory, and anticancer properties, which can be used to treat several diseases. Further studies are needed to investigate their sizes, dose-dependent activities, and mechanisms of action.

Atomically Precise Gold-Levonorgestrel Nanocluster as a Radiosensitizer for Enhanced Cancer Therapy

Gold nanoclusters have become promising radiosensitizers due to their ultrasmall size and robust ability to adsorb, scatter, and re-emit radiation. However, most of the previously reported gold nanocluster radiosensitizers do not have a precise atomic structure, causing difficulties in understanding the structure-activity relationship. In this study, a structurally defined gold-levonorgestrel nanocluster consisting of Au₈(C₂₁H₂₇O₂)₈ (Au₈NC) with bright luminescence (58.7% quantum yield) and satisfactory biocompatibility was demonstrated as a nanoradiosensitizer. When the Au₈NCs were irradiated with X-rays, they produced reactive oxygen species (ROS), resulting in irreversible cell apoptosis. As indicated by in vivo tumor formation experiments, tumorigenicity was significantly suppressed after one radiotherapy treatment with the Au₈NCs. In addition, compared with tumors treated with X-rays (4 Gy) alone, tumors treated with the nanosensitizer exhibited an inhibition rate of 74.2%. This study contributes to the development of atomically precise gold nanoclusters as efficient radiosensitizers.

Synthesis and characterization of gold nanoparticles from Abies spectabilis extract and its anticancer activity on bladder cancer T24 cells

In recent times, Gold nanoparticles (AuNPs) synthesized from plant extracts and their anticancer activity have attracted significant attention. We report the green approach for the synthesis of AuNPs using extract from Abies spectabilis plant. In this study, the reaction parameters were optimized to control the size of the nanoparticle, which was confirmed by Transmission Electron microscopy (TEM). Various characterization technique such as SAED pattern, UV visible spectroscopy, EDX, FTIR, and AFM were employed to analyze the synthesized AuNPs obtained from A. spectabilis plant extract. Furthermore, we investigated the anticancer activities using T24 cell lines. Interestingly, the results of extensive screening on the applications of newly synthesized AuNPs were tested for their cytotoxicity effects on anticancer activity against T24 cells by MTT assay. The cell apoptosis was studied using TUNEL, DAPI, caspase activity, cell invasion and migration. Nanoparticles at different concentrations ranging from 1 to 25 μg/ml exhibited a dose dependent cytotoxicity for 24 h. Condensation and DNA fragmentation are characteristic of apoptosis by DAPI, TUNEL staining, and the significant up regulations of Beclin-1, Bax and caspase 3, whereas the expressions of anti-apoptotic Bcl-2 and Bid were down regulated. However, this study, therefore attempts to report the synthesis, characterization, and anticancer activity of gold nanoparticles of A. spectabilis plant extract beneficial for cancer therapeutics.

Gold as a Possible Alternative to Platinum-Based Chemotherapy for Colon Cancer Treatment

Due to the increasing incidence and high mortality associated with colorectal cancer (CRC), novel therapeutic strategies are urgently needed. Classic chemotherapy against CRC is based on oxaliplatin and other cisplatin analogues; however, platinum-based therapy lacks selectivity to cancer cells and leads to deleterious side effects. In addition, tumor resistance to oxaliplatin is related to chemotherapy failure. Gold(I) derivatives are a promising alternative to platinum complexes, since instead of interacting with DNA, they target proteins overexpressed on tumor cells, thus leading to less side effects than, but a comparable antitumor effect to, platinum derivatives. Moreover, given the huge potential of gold nanoparticles, the role of gold in CRC chemotherapy is not limited to gold(I) complexes. Gold nanoparticles have been found to be able to overcome multidrug resistance along with reduced side effects due to a more efficient uptake of classic drugs. Moreover, the use of gold nanoparticles has enhanced the effect of traditional therapies such as radiotherapy, photothermal therapy, or photodynamic therapy, and has displayed a potential role in diagnosis as a consequence of their optic properties. Herein, we have reviewed the most recent advances in the use of gold(I) derivatives and gold nanoparticles in CRC therapy.

The role of thioredoxin reductase in gold nanoparticle radiosensitization effects

Aim: To identify new mechanisms responsible for the radiosensitization effect of gold nanoparticles (GNPs). Materials & methods: A549 lung carcinoma cells were incubated with 10-nm GNPs during 6 or 24 h before to be exposed to 25 keV/μm protons or 225 kV x-rays. Results: GNP incubation led to a time-dependent mitochondria membrane depolarization, oxidative stress and to x-ray and proton radiosensitization. Moreover, a marked inhibition of thioredoxin reductase was observed. Irradiation of cells invalidated for thioredoxin reductase evidenced a radiosensitization effect, suggesting that this enzyme is a potential GNP target. Conclusion: We suggest that GNPs play a radiosensitizer role by weakening detoxification systems. Altogether, these results open up promising novel strategies for the development of nanotechnologies associated to radiotherapy.

Single Intense Microsecond Electric Pulse Induces Radiosensitization to Ionizing Radiation: Effects of Time Intervals Between Electric Pulse and Ionizing Irradiation

Background and Objective: Recent studies have shown the potential of electroporation (EP) as a physical radiosensitizer for ionizing radiation (IR). The amount of sensitizing effect depends on some factors the most important of them is the time interval between the EP and IR. This experimental in vitro study aims to investigate the radiosensitizing effect of EP exposure prior to IR and also evaluate the effects of EP-IR time intervals on the amount of radiosensitizing effects.

Methods: Chinese hamster ovary (CHO) cell lines were cultured in vitro. The cells were divided into 10 groups including one untreated or control group, IR, and EP treatment alone groups, and seven combined EP-IR groups with 10, 20, 30, 40, 50, 60, and 70 min intervals. The dose enhancement factors (DEFs) for 6 MV X-rays IR were comparatively investigated between the groups using MTT assay.

Results: The EP significantly induced radiosensitizing effect and its amount depends on the time intervals. The viability rate of the cells in the combined EP-IR treatment groups for intervals of 10, 20, 30, 40, and 50 min was significantly lower than the IR alone group. The highest DEF (1.18) was observed 10 min time interval between EP and IR.

Conclusion: The radiosensitizing effects of EP persist long enough, 10–50 min, which allows safe application of EP as a radiosensitizer before IR in clinical setting.