Gold nanoparticles in combinatorial cancer therapy strategies

Hidden in Plants-A Review of the Anticancer Potential of the Solanaceae Family in In Vitro and In Vivo Studies

Many of the anticancer agents that are currently in use demonstrate severe side effects and encounter increasing resistance from the target cancer cells. Thus, despite significant advances in cancer therapy in recent decades, there is still a need to discover and develop new, alternative anticancer agents. The plant kingdom contains a range of phytochemicals that play important roles in the prevention and treatment of many diseases. The Solanaceae family is widely used in the treatment of various diseases, including cancer, due to its bioactive ingredient content. The purpose of this literature review is to highlight the antitumour activity of Solanaceae extracts-single isolated compounds and nanoparticles with extracts-and their synergistic effect with chemotherapeutic agents in various in vitro and in vivo cancer models. In addition, the biological properties of many plants of the Solanaceae family have not yet been investigated, which represents a challenge and an opportunity for future anticancer therapy.

Recent Progress in Nanostructured Smart Drug Delivery Systems for Cancer Therapy: A Review

Traditional treatment approaches for cancer involve intravenous chemotherapy or other forms of drug delivery. These therapeutic measures suffer from several limitations such as nonspecific targeting, poor biodistribution, and buildup of drug resistances. However, significant technological advancements have been made in terms of superior modes of drug delivery over the last few decades. Technical capability in analyzing the molecular mechanisms of tumor biology, nanotechnology─particularly the development of biocompatible nanoparticles, surface modification techniques, microelectronics, and material sciences─has increased. As a result, a significant number of nanostructured carriers that can deliver drugs to specific cancerous sites with high efficiency have been developed. This particular maneuver that enables the introduction of a therapeutic nanostructured substance in the body by controlling the rate, time, and place is defined as the nanostructured drug delivery system (NDDS). Because of their versatility and ability to incorporate features such as specific targeting, water solubility, stability, biocompatibility, degradability, and ability to reverse drug resistance, they have attracted the interest of the scientific community, in general, and nanotechnologists as well as biomedical scientists. To keep pace with the rapid advancement of nanotechnology, specific technical aspects of the recent NDDSs and their prospects need to be reported coherently. To address these ongoing issues, this review article provides an overview of different NDDSs such as lipids, polymers, and inorganic nanoparticles. In addition, this review also reports the challenges of current NDDSs and points out the prospective research directions of these nanocarriers. From our focused review, we conclude that still now the most advanced and potent field of application for NDDSs is lipid-based, while other significantly potential fields include polymer-based and inorganic NDDSs. However, despite the promises, challenges remain in practical implementations of such NDDSs in terms of dosage and stability, and caution should be exercised regarding biocompatibility of materials. Considering these aspects objectively, this review on NDDSs will be particularly of interest for small-to-large scale industrial researchers and academicians with expertise in drug delivery, cancer research, and nanotechnology.

Fe3O4@Au core-shell hybrid nanocomposite for MRI-guided magnetic targeted photo-chemotherapy

The combination of multiple therapeutic and diagnostic functions is fast becoming a key feature in the area of clinical oncology. The advent of nanotechnology promises multifunctional nanoplatforms with the potential to deliver multiple therapeutics while providing diagnostic information simultaneously. In this study, novel iron oxide-gold core-shell hybrid nanocomposites (Fe₃O₄@Au HNCs) coated with alginate hydrogel carrying doxorubicin (DOX) were constructed for targeted photo-chemotherapy and magnetic resonance imaging (MRI). The magnetic core enables the HNCs to be detected through MRI and targeted towards the tumor using an external magnetic field, a method known as magnetic drug targeting (MDT). The Au shell could respond to light in the near-infrared (NIR) region, generating a localized heating for photothermal therapy (PTT) of the tumor. The cytotoxicity assay showed that the treatment of CT26 colon cancer cells with the DOX-loaded HNCs followed by laser irradiation induced a significantly higher cell death as opposed to PTT and chemotherapy alone. The in vivo MRI study proved MDT to be an effective strategy for targeting the HNCs to the tumor, thereby enhancing their intratumoral concentration. The antitumor study revealed that the HNCs can successfully combine chemotherapy and PTT, resulting in superior therapeutic outcome. Moreover, the use of MDT following the injection of HNCs caused a more extensive tumor shrinkage as compared to non-targeted group. Therefore, the as-prepared HNCs could be a promising nanoplatform for image-guided targeted combination therapy of cancer.

Green synthesis of ZrO2 nanoparticles and nanocomposites for biomedical and environmental applications: a review

Pollution and diseases such as the coronavirus pandemic (COVID-19) are major issues that may be solved partly by nanotechnology. Here we review the synthesis of ZrO₂ nanoparticles and their nanocomposites using compounds from bacteria, fungi, microalgae, and plants. For instance, bacteria, microalgae, and fungi secret bioactive metabolites such as fucoidans, digestive enzymes, and proteins, while plant tissues are rich in reducing sugars, polyphenols, flavonoids, saponins, and amino acids. These compounds allow reducing, capping, chelating, and stabilizing during the transformation of Zr⁴⁺ into ZrO₂ nanoparticles. Green ZrO₂ nanoparticles display unique properties such as a nanoscale size of 5-50 nm, diverse morphologies, e.g. nanospheres, nanorods and nanochains, and wide bandgap energy of 3.7-5.5 eV. Their high stability and biocompatibility are suitable biomedical and environmental applications, such as pathogen and cancer inactivation, and pollutant removal. Emerging applications of green ZrO₂-based nanocomposites include water treatment, catalytic reduction, nanoelectronic devices, and anti-biofilms.

Collagen – A Newly Discovered Major Player in Protein Corona Formation on Nanoparticles

Tracking protein corona (PC) formation on the surface of nanoparticles (NPs) is a prerequisite for successful design of next generation nanocarriers with predictable fate and behavior. However, PC formation has...

Vaccine delivery systems toward lymph nodes

Strategies of improving vaccine targeting ability toward lymph nodes have been attracting considerable interest in recent years, though there are remaining delivery barriers based on the inherent properties of lymphatic systems and limited administration routes of vaccination. Recently, emerging vaccine delivery systems using various materials as carriers are widely developed to achieve efficient lymph node targeting and improve vaccine-triggered adaptive immune response. In this review, to further optimize the vaccine targeting ability for future research, the design principles of lymph node targeting vaccine delivery based on the anatomy of lymph nodes and vaccine administration routes are first summarized. Then different designs of lymph node targeting vaccine delivery systems, including vaccine delivery systems in clinical applications, are carefully surveyed. Also, the challenges and opportunities of current delivery systems for vaccines are concluded in the end.

Organic/Inorganic Self-Assembled Hybrid Nano-Architectures for Cancer Therapy Applications

Since the conceptualization of nanomedicine, numerous nanostructure-mediated drug formulations have progressed into clinical trials for treating cancer. However, recent clinical trial results indicate such kind of drug formulations has a limited improvement on the antitumor efficacy. This is due to the biological barriers associated with those formulations, for example, circulation stability, extravasation efficiency in tumor, tumor penetration ability, and developed multi-drug resistance. When employing for nanomedicine formulations, pristine organic-based and inorganic-based nanostructures have their own limitations. Accordingly, organic/inorganic (O/I) hybrids have been developed to integrate the merits of both, and to minimize their intrinsic drawbacks. In this context, the recent development in O/I hybrids resulting from a self-assembly strategy will be introduced. Through such a strategy, organic and inorganic building blocks can be self-assembled via either chemical covalent bonds or physical interactions. Based on the self-assemble procedure, the hybridization of four organic building blocks including liposomes, micelles, dendrimers, and polymeric nanocapsules with five functional inorganic nanoparticles comprising gold nanostructures, magnetic nanoparticles, carbon-based materials, quantum dots, and silica nanoparticles will be highlighted. The recent progress of these O/I hybrids in advanced modalities for combating cancer, such as, therapeutic agent delivery, photothermal therapy, photodynamic therapy, and immunotherapy will be systematically reviewed.

The promise of low-intensity ultrasound: A review on sonosensitizers and sonocatalysts by ultrasonic activation for bacterial killing

Antimicrobial resistance has become one of the main public health issues in modern society. Ultrasonicantimicrobial treatment (UAT) is expected to solve the problem of antimicrobial resistance since ultrasonic treatment does not cause drug resistance during inactivation. However, the ultrasonic application is hindered due to the high energy cost. To cast more lights on the ultrasound in tandem with catalysts as a superior strategy for bacterial inactivation, the present review focuses on the UAT with the assistant of continuous development of organic sonosensitizer and inorganic sonocatalyst. With the application of these nanomaterials, the ultrasonic parameters changed from low-frequency and high-power ultrasound to high-frequency and low-power ultrasound. The review also presents the composition of sonosensitizers/sonocatalysts including organic and inorganic nanoparticles and discusses the ultrasonic activation mechanisms triggered by these catalysts. Based on the synergistic effect of ultrasound and catalysts, we discuss the importance of extracellular oxidation and intracellular oxidation in the process of bacterial inactivation. Overall, UAT combined with catalysts appears to be an effective treatment strategy that can be successfully applied in the field of medicine, environmental treatment, and food industry.

Application of Gold Nanoparticle-Based Materials in Cancer Therapy and Diagnostics

Several metal nanoparticles have been developed for medical application. While all have their benefits, gold nanoparticles (AuNPs) are ideal in cancer therapy and diagnosis as they are chemically inert and minimally toxic. Several studies have shown the potential of AuNPs in the therapeutic field, as photosensitizing agents in sonochemical and photothermal therapy and as drug delivery, as well as in diagnostics and theranostics. Although there is a significant number of reviews on the application of AuNPs in cancer medicine, there is no comprehensive review on their application both in therapy and diagnostics. Therefore, considering the high number of studies on AuNPs’ applications, this review summarizes data on the application of AuNPs in cancer therapy and diagnostics. In addition, we looked at the influence of AuNPs’ shape and size on their biological properties. We also present the potential use of hybrid materials based on AuNPs in sonochemical and photothermal therapy and the possibility of their use in diagnostics. Despite their potential, the use of AuNPs and derivatives in cancer medicine still has some limitations. In this review, we provide an overview of the biological, physicochemical, and legal constraints on using AuNPs in cancer medicine.

Synthesis and characterization of gold nanorods coated by mesoporous silica MCM-41 as a platform bioapplication in photohyperthermia

Gold nanoparticles have been widely investigated for biomedical applications due to their optical properties. These particles present the interesting feature of absorbing light when stimulated with laser radiation to generate heating. Among the possible morphologies for synthetic gold nanoparticles, gold nanorods have properties of great interest for applications in the photohyperthermia processes. Due to their morphology, gold nanorods can absorb light at longer wavelengths comprising specific regions of the electromagnetic spectrum, such as the region of the biological window, in which laser radiation has less interaction with tissues. However, these nanoparticles present limitations in biomedical applications, such as low colloidal and thermal stabilities that can be overcome by coating the gold nanorods with silica MCM-41. The silicate covering can provide greater stability for gold nanorods and allow multifunctionality in treating different diseases through photohyperthermia. This work developed a specific chemical route through seed and growth solutions to synthesize gold nanorods with controlled particle size, rod morphology, and silica covering for photohyperthermia applications. The synthesized samples were characterized through a multi-technique approach that successfully demonstrated the presence of gold nanorods inside the silica coating, presenting high stability and desirable textural and morphological characteristics for bioapplications. Furthermore, silica-coated gold nanorods exhibit high biocompatibility and great performance in generating therapeutic heating by absorbing laser radiation in the biological window range, making the system developed in this work a promising agent in photohyperthermia.

Recent advances in assembled AIEgens for image-guided anticancer therapy

Image-guided therapy, with simultaneous imaging and therapy functions, has the potential to greatly enhance the therapeutic efficacy of anticancer therapy, and reduce the incidence of side effects. Fluorescence imaging has the advantages of easy operation, abundant signal, high contrast, and fast response for real-time and non-invasive tracking. Luminogens with aggregation-induced emission characteristics (AIEgens) can emit strong luminescence in an aggregate state, which makes them ideal materials to construct applicative fluorophores for fluorescence imaging. The opportunity for image-guided cancer treatment has inspired researchers to explore the theranostic application of AIEgens combined with other therapy methods. In recent years, many AIEgens with efficient photosensitizing or photothermal abilities have been designed by precise molecular engineering, with superior performance in image-guided anticancer therapy. Owing to the hydrophobic property of most AIEgens, an assembly approach has been wildly utilized to construct biocompatible AIEgen-based nanostructures in aqueous systems, which can be used for image-guided anticancer therapy. In the present review, we summarize the recent advances in the assembled AIEgens for image-guided anticancer therapy. Five types of image-guided anticancer therapy using assembled AIEgens are included: chemotherapy, photodynamic therapy, photothermal therapy, gene therapy, and synergistic therapy. Moreover, a brief conclusion with the discussion of current challenges and future perspectives in this area is further presented.

Snail slime-based gold nanoparticles: An interesting potential ingredient in cosmetics as an antioxidant, sunscreen, and tyrosinase inhibitor

Due to their properties, snail slime-based products have been appreciated and used worldwide. So, as an alternative and innovative use of snail slime, it was adopted to induce gold nanoparticles' formation, conferring them interesting properties. By a simple, one-pot, and eco-friendly approach, 14 ± 6 nm wide hybrid gold nanoparticles, having an inorganic metallic core decorated by the slime's main components, were obtained. Among their several properties, their antioxidant and tyrosinase inhibition activity were investigated through the DPPH and ABTS and the tyrosinase assays, respectively. After assessing their non-cytotoxicity in our previous work, the results revealed positive responses, enabling their use as a potential novel multifunctional ingredient in cosmetics. Interestingly, the gold nanoparticle photostability, investigated by means of a solar simulator lamp, suggests using them in commercial cosmetic sunscreen products as a potential alternative to the commonly used inorganic sunscreen ingredients. The theoretical Sun Protection Factor was evaluated, obtaining values in the range 0-12. The proposed environmentally friendly and cost-effective protocol for nanoparticle synthesis, following the principles of Green Chemistry, opens a hugely attractive space toward the study of snail slime-based gold nanoparticles as a potential multipurpose platform in cosmetics.

Prospects of Cationic Carbosilane Dendronized Gold Nanoparticles as Non-viral Vectors for Delivery of Anticancer siRNAs siBCL-xL and siMCL-1

Cancer is one of the most important problems of modern medicine. At the present time, gene therapy has been developed against cancer, which includes the delivery of anticancer small interfering RNAs (siRNAs) directed at cancer proteins. The prospect of creating drugs based on RNA interference implies the use of delivery systems. Metal nanoparticles are the most studied objects for medicine, including their application as non-viral vectors. We have synthesized gold nanoparticles (AuNPs) modified with cationic carbosilane dendrons of 1-3 generations, with a positive charge on the surface, gold nanoparticles can effectively bind small interfering RNAs. Using a photometric viability test and flow cytometry, we assessed the ability of dendronized gold nanoparticles in delivering siRNAs to tumor cells. The efficiency of the complexes in initiating apoptosis was measured and, also, the overall effect of proapoptotic siRNA on cells. AuNP15 has both the highest efficacy and toxicity. The delivery efficiency in suspension cell lines was 50-60%. Complexes with targeted siRNA decreased cell viability by 20% compared to control and initiated apoptosis.

Advances in Nanomaterials Used in Co-Delivery of siRNA and Small Molecule Drugs for Cancer Treatment

Recent advancements in nanotechnology have improved our understanding of cancer treatment and allowed the opportunity to develop novel delivery systems for cancer therapy. The biological complexities of cancer and tumour micro-environments have been shown to be highly challenging when treated with a single therapeutic approach. Current co-delivery systems which involve delivering small molecule drugs and short-interfering RNA (siRNA) have demonstrated the potential of effective suppression of tumour growth. It is worth noting that a considerable number of studies have demonstrated the synergistic effect of co-delivery systems combining siRNA and small molecule drugs, with promising results when compared to single-drug approaches. This review focuses on the recent advances in co-delivery of siRNA and small molecule drugs. The co-delivery systems are categorized based on the material classes of drug carriers. We discuss the critical properties of materials that enable co-delivery of two distinct anti-tumour agents with different properties. Key examples of co-delivery of drug/siRNA from the recent literature are highlighted and discussed. We summarize the current and emerging issues in this rapidly changing field of research in biomaterials for cancer treatments.

Nanomaterials for the Diagnosis and Treatment of Head and Neck Cancers: A Review

Head and neck cancer (HNC) is a category of cancers that typically arise from the nose-, mouth-, and throat-lining squamous cells. The later stage of HNC diagnosis significantly affects the patient's survival rate. This makes it mandatory to diagnose this cancer with a suitable biomarker and imaging techniques at the earlier stages of growth. There are limitations to traditional technologies for early detection of HNC. Furthermore, the use of nanocarriers for delivering chemo-, radio-, and phototherapeutic drugs represents a promising approach for improving the outcome of HNC treatments. Several studies with nanostructures focus on the development of a targeted and sustained release of anticancer molecules with reduced side effects. Besides, nanovehicles could allow co-delivering of anticancer drugs for synergistic activity to counteract chemo- or radioresistance. Additionally, a new generation of smart nanomaterials with stimuli-responsive properties have been developed to distinguish between unique tumor conditions and healthy tissue. In this light, the present article reviews the mechanisms used by different nanostructures (metallic and metal oxide nanoparticles, polymeric nanoparticles, quantum dots, liposomes, nanomicelles, etc.) to improve cancer diagnosis and treatment, provides an up-to-date picture of the state of the art in this field, and highlights the major challenges for future improvements.

Peptide-Enabled Targeted Delivery Systems for Therapeutic Applications

Receptor-targeting peptides have been extensively pursued for improving binding specificity and effective accumulation of drugs at the site of interest, and have remained challenging for extensive research efforts relating to chemotherapy in cancer treatments. By chemically linking a ligand of interest to drug-loaded nanocarriers, active targeting systems could be constructed. Peptide-functionalized nanostructures have been extensively pursued for biomedical applications, including drug delivery, biological imaging, liquid biopsy, and targeted therapies, and widely recognized as candidates of novel therapeutics due to their high specificity, well biocompatibility, and easy availability. We will endeavor to review a variety of strategies that have been demonstrated for improving receptor-specificity of the drug-loaded nanoscale structures using peptide ligands targeting tumor-related receptors. The effort could illustrate that the synergism of nano-sized structures with receptor-targeting peptides could lead to enrichment of biofunctions of nanostructures.

Lactoferrin-Bearing Gold Nanocages for Gene Delivery in Prostate Cancer Cells in vitro

BACKGROUND

Gold nanocages have been widely used as multifunctional platforms for drug and gene delivery, as well as photothermal agents for cancer therapy. However, their potential as gene delivery systems for cancer treatment has been reported in combination with chemotherapeutics and photothermal therapy, but not in isolation so far. The purpose of this work was to investigate whether the conjugation of gold nanocages with the cancer targeting ligand lactoferrin, polyethylene glycol and polyethylenimine could lead to enhanced transfection efficiency on prostate cancer cells in vitro, without assistance of external stimulation.

METHODS

Novel lactoferrin-bearing gold nanocages conjugated to polyethylenimine and polyethylene glycol have been synthesized and characterized. Their transfection efficacy and cytotoxicity were assessed on PC-3 prostate cancer cell line following complexation with a plasmid DNA.

RESULTS

Lactoferrin-bearing gold nanocages, alone or conjugated with polyethylenimine and polyethylene glycol, were able to condense DNA at conjugate:DNA weight ratios 5:1 and higher. Among all gold conjugates, the highest gene expression was obtained following treatment with gold complex conjugated with polyethylenimine and lactoferrin, at weight ratio 40:1, which was 1.71-fold higher than with polyethylenimine. This might be due to the increased DNA cellular uptake observed with this conjugate, by up to 8.65-fold in comparison with naked DNA.

CONCLUSION

Lactoferrin-bearing gold nanocages conjugates are highly promising gene delivery systems to prostate cancer cells.

Evaluation of the Anticancer Activity of Phytomolecules Conjugated Gold Nanoparticles Synthesized by Aqueous Extracts of Zingiber officinale (Ginger) and Nigella sativa L. Seeds (Black Cumin)

The conventional physical and chemical synthetic methods for the preparation of metal nanoparticles have disadvantages as they use expensive equipment and hazardous chemicals which limit their applications for biomedical purposes, and are not environment friendly. However, for the synthesis of biocompatible nanomaterials, plant-based techniques are eco-friendly and easy to handle. Herein a simple, single-step biosynthesis of gold nanoparticles using aqueous extracts of Nigella sativa (NSE) and Zingiber officinale (GE) as a reducing and capping agent has been demonstrated. The formation of gold nanoparticles (Au NPs) was confirmed by X-ray diffraction, UV-Vis, and EDS spectroscopies. Spectroscopic and chromatographic analysis of GE and NSE revealed the presence of bioactive phytochemical constituents, such as gingerol, thymoquinone, etc., which successfully conjugated the surface of resulting Au NPs. TEM analysis indicated the formation of smaller-sized, less-aggregated, spherical-shaped Au NPs both in the case of GE (~9 nm) and NSE (~11 nm). To study the effect of the concentration of the extracts on the quality of resulting NPs and their anticancer properties, three different samples of Au NPs were prepared from each extract by varying the concentration of extracts while keeping the amount of precursor constant. In both cases, high-quality, spherical-shaped NPs were obtained, only at a high concentration of the extract, whereas at lower concentrations, larger-sized, irregular-shaped NPs were formed. Furthermore, the as-prepared Au NPs were evaluated for the anticancer properties against two different cell lines including MDA-MB-231 (breast cancer) and HCT 116 (colorectal cancer) cell lines. GE-conjugated Au NPs obtained by using a high concentration of the extract demonstrated superior anticancer properties when compared to NSE-conjugated counterparts.

Lipoperoxide Nanoemulsion as Adjuvant in Cisplatin Cancer Therapy: In Vitro Study on Human Colon Adenocarcinoma DLD-1 Cells

Cisplatin is a first-choice chemotherapeutic agent used to treat solid tumors even though the onset of multi-drug resistance and the time-dose side-effects impair its mono-therapeutic application. Therefore, new drug-delivery approaches, based on nanomedicine strategies, are needed to enhance its therapeutic potential in favor of a dose-reduction of cisplatin. Polyunsaturated fatty acids and their metabolism-derived intermediates, as well as lipid peroxidation end-products, are used as adjuvants to improve the effectiveness of chemotherapy. Lipid hydroperoxides, derived from the oxidation of edible oils, can contribute to cell death, generating breakdown products (e.g., reactive aldehydes). In this regard, the aim of this present study was to evaluate an invitro combinatory strategy between a lecithin-based nanoemulsion system of K600, a patented mixture of peroxidated oil and peroxidated cholesterol, and cisplatin on DLD1 human adenocarcinoma cells. Our findings showed that nanoemulsions, acting in synergy with cisplatin, improve cisplatin bioactivity, in terms of enhancing its anti-cancer activity, towards DLD1 cells. Indeed, this combination approach, whilst maintaining cisplatin at low concentrations, induces a significant reduction in DLD1 cell viability, an increase in pro-apoptotic markers, and genotoxic damage. Therefore, K600 nanoemulsions as an efficient targeted delivery system of cisplatin allow for the reduction in the chemotherapeutic agent doses.

An Updated Review on Implications of Autophagy and Apoptosis in Tumorigenesis: Possible Alterations in Autophagy through Engineered Nanomaterials and Their Importance in Cancer Therapy

Most commonly recognized as a catabolic pathway, autophagy is a perplexing mechanism through which a living cell can free itself of excess cytoplasmic components, i.e., organelles, by means of certain membranous vesicles or lysosomes filled with degrading enzymes. Upon exposure to external insult or internal stimuli, the cell might opt to activate such a pathway, through which it can gain control over the maintenance of intracellular components and thus sustain homeostasis by intercepting the formation of unnecessary structures or eliminating the already present dysfunctional or inutile organelles. Despite such appropriateness, autophagy might also be considered a frailty for the cell, as it has been said to have a rather complicated role in tumorigenesis. A merit in the early stages of tumor formation, autophagy appears to be salutary because of its tumor-suppressing effects. In fact, several investigations on tumorigenesis have reported diminished levels of autophagic activity in tumor cells, which might result in transition to malignancy. On the contrary, autophagy has been suggested to be a seemingly favorable mechanism to progressed malignancies, as it contributes to survival of such cells. Based on the recent literature, this mechanism might also be activated upon the entry of engineered nanomaterials inside a cell, supposedly protecting the host from foreign materials. Accordingly, there is a good chance that therapeutic interventions for modulating autophagy in malignant cells using nanoparticles may sensitize cancerous cells to certain treatment modalities, e.g., radiotherapy. In this review, we will discuss the signaling pathways involved in autophagy and the significance of the mechanism itself in apoptosis and tumorigenesis while shedding light on possible alterations in autophagy through engineered nanomaterials and their potential therapeutic applications in cancer. SIGNIFICANCE STATEMENT: Autophagy has been said to have a complicated role in tumorigenesis. In the early stages of tumor formation, autophagy appears to be salutary because of its tumor-suppressing effects. On the contrary, autophagy has been suggested to be a favorable mechanism to progressed malignancies. This mechanism might be affected upon the entry of nanomaterials inside a cell. Accordingly, therapeutic interventions for modulating autophagy using nanoparticles may sensitize cancerous cells to certain therapies.

The reversal of chemotherapy-induced multidrug resistance by nanomedicine for cancer therapy

Multidrug resistance (MDR) of cancer is a persistent problem in chemotherapy. Scientists have considered the overexpressed efflux transporters responsible for MDR and chemotherapy failure. MDR extremely limits the therapeutic effect of chemotherapy in cancer treatment. Many strategies have been applied to solve this problem. Multifunctional nanoparticles may be one of the most promising approaches to reverse MDR of tumor. These nanoparticles can keep stability in the blood circulation and selectively accumulated in the tumor microenvironment (TME) either by passive or active targeting. The stimuli-sensitive or organelle-targeting nanoparticles can release the drug at the targeted-site without exposure to normal tissues. In order to better understand reversal of MDR, three main strategies are concluded in this review. First strategy is the synergistic effect of chemotherapeutic drugs and ABC transporter inhibitors. Through directly inhibiting overexpressed ABC transporters, chemotherapeutic drugs can enter into resistant cells without being efflux. Second strategy is based on nanoparticles circumventing over-expressed efflux transporters and directly targeting resistance-related organelles. Third approach is the combination of multiple therapy modes overcoming cancer resistance. At last, numerous researches demonstrated cancer stem-like cells (CSCs) had a deep relation with drug resistance. Here, we discuss two different drug delivery approaches of nanomedicine based on CSC therapy.

Nanomaterials to Fight Cancer: An Overview on Their Multifunctional Exploitability

In recent years the worldwide research community has highlighted innumerable benefits of nanomaterials in cancer detection and therapy. Nevertheless, the development of cancer nanomedicines and other bionanotechnology requires a huge amount of considerations about the interactions of nanomaterials and biological systems, since long-term effects are not yet fully known. Open issues remain the determination of the nanoparticles distributions patterns and the internalization rate into the tumor while avoiding their accumulation in internal organs or other healthy tissues. The purpose of this work is to provide a standard overview of the most recent advances in nanomaterials to fight cancer and to collect trends and future directions to follow according to some critical aspects still present in this field. Complementary to the very recent review of Wolfram and Ferrari which discusses and classifies successful clinically-approved cancer nanodrugs as well as promising candidates in the pipeline, this work embraces part of their proposed classification system based on the exploitation of multifunctionality and extends the review to peer-reviewed journal articles published in the last 3 years identified through international databases.

Facile synthesis of Au/ZnO/Ag nanoparticles using Glechoma hederacea L. extract, and their activity against leukemia

Metal combinations have been attracting the attention of scientists for some time. They usually exhibit new characteristics that are different from the ones possessed by their components. In this work, Au/ZnO/Ag nanoparticles were synthesized biologically using Glechoma hederacea L. extract. The synthesized Au/ZnO/Ag nanoparticles were characterized by UV-Vis, Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), and Atomic Force Microscopy (AFM). The microscopic methods confirmed the presence of spherical nanoparticles of 50–70 nm. The influence of biologically synthesized Au/ZnO/Ag nanoparticles on the vitality of human cells was evaluated in vitro with the use of established human Acute T Cell Leukemia cell line, Jurkat (ATCC® TIB-152™), as well as mononuclear cells isolated from peripheral blood (PBMC) of voluntary donors. Cell survival and the half-maximal inhibitory concentration index (IC50) were analyzed by the MTT test. The studies showed that the total loss of cell viability occurred at the Au/ZnO/Ag nanoparticle concentration range of 10 µmol–50 µmol. The use of Au/ZnO/Ag nanoparticles at the concentration of 100 µmol eliminated almost all living cells from the culture in 24h. The above observation confirms the result obtained during the MTT test.

Recent advances in cancer photo-theranostics: the synergistic combination of transition metal complexes and gold nanostructures

In this mini review, we highlight advances in the last five years in light-activated cancer theranostics by using hybrid systems consisting of transition metal complexes (TMCs) and plasmonic gold nanostructures (AuNPs). TMCs are molecules with attractive properties and high potential in biomedical application. Due to their antiproliferative abilities, platinum-based compounds are currently first-choice drugs for the treatment of several solid tumors. Moreover, ruthenium, iridium and platinum complexes are well-known for their ability to photogenerate singlet oxygen, a highly cytotoxic reactive species with a key role in photodynamic therapy. Their potential is further extended by the unique photophysical properties, which make TMCs particularly suitable for bioimaging. Recently, gold nanoparticles (AuNPs) have been widely investigated as one of the leading nanomaterials in cancer theranostics. AuNPs—being an inert and highly biocompatible material—represent excellent drug delivery systems, overcoming most of the side effects associated with the systemic administration of anticancer drugs. Furthermore, due to the thermoplasmonic properties, AuNPs proved to be efficient nano-sources of heat for photothermal therapy application. Therefore, the hybrid combination TMC/AuNPs could represent a synergistic merger of multiple functionalities for combinatorial cancer therapy strategies. Herein, we report the most recent examples of TMC/AuNPs systems in in-vitro in-vivo cancer tharanostics application whose effects are triggered by light-exposure in the Vis–NIR region, leading to a spatial and temporal control of the TMC/AuNPs activation for light-mediated precision therapeutics.

Combined cancer therapeutics-Tackling the complexity of the tumor microenvironment

Cancer treatment has yet to find a "silver bullet" capable of selectively and effectively kill tumor cells without damaging healthy cells. Nanomedicine is a promising field that can combine several moieties in one system to produce a multifaceted nanoplatform. The tumor microenvironment (TME) is considered responsible for the ineffectiveness of cancer therapeutics and the difficulty in the translation from the bench to bed side of novel nanomedicines. A promising approach is the use of combinatorial therapies targeting the TME with the use of stimuli-responsive nanomaterials which would increase tumor targeting. Contemporary combined strategies for TME-targeting nanoformulations are based on the application of external stimuli therapies, such as photothermy, hyperthermia or ultrasounds, in combination with stimuli-responsive nanoparticles containing a core, usually composed by metal oxides or graphene, and a biocompatible stimuli-responsive coating layer that could also contain tumor targeting moieties and a chemotherapeutic agent to enhance the therapeutic efficacy. The obstacles that nanotherapeutics must overcome in the TME to accomplish an effective therapeutic cargo delivery and the proposed strategies for improved nanotherapeutics will be reviewed. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Inorganic Nanomaterial-Mediated Gene Therapy in Combination with Other Antitumor Treatment Modalities

Cancer is a genetic disease originating from the accumulation of gene mutations in a cellular subpopulation. Although many therapeutic approaches have been developed to treat cancer, recent studies have revealed an irrefutable challenge that tumors evolve defenses against some therapies. Gene therapy may prove to be the ultimate panacea for cancer by correcting the fundamental genetic errors in tumors. The engineering of nanoscale inorganic carriers of cancer therapeutics has shown promising results in the efficacious and safe delivery of nucleic acids to treat oncological diseases in small-animal models. When these nanocarriers are used for co-delivery of gene therapeutics along with auxiliary treatments, the synergistic combination of therapies often leads to an amplified health benefit. In this review, an overview of the inorganic nanomaterials developed for combinatorial therapies of gene and other treatment modalities is presented. First, the main principles of using nucleic acids as therapeutics, inorganic nanocarriers for medical applications and delivery of gene/drug payloads are introduced. Next, the utility of recently developed inorganic nanomaterials in different combinations of gene therapy with each of chemo, immune, hyperthermal, and radio therapy is examined. Finally, current challenges in the clinical translation of inorganic nanomaterial-mediated therapies are presented and outlooks for the field are provided.

Abdulbaqi I, Parumasivam T, Mohtar N, A. Wahab H. Advances in Nanocarriers for Effective Delivery of Docetaxel in the Treatment of Lung Cancer: An Overview

Docetaxel (DCX) is a highly effective chemotherapeutic drug used in the treatment of different types of cancer, including non-small cell lung cancer (NSCLC). The drug is known to have low oral bioavailability due to its low aqueous solubility, poor membrane permeability and susceptibility to hepatic first-pass metabolism. To mitigate these problems, DCX is administered via the intravenous route. Currently, DCX is commercially available as a single vial that contains polysorbate 80 and ethanol to solubilize the poorly soluble drug. However, this formulation causes short- and long-term side effects, including hypersensitivity, febrile neutropenia, fatigue, fluid retention, and peripheral neuropathy. DCX is also a substrate to the drug efflux pump P-glycoprotein (P-gp) that would reduce its concentration within the vicinity of the cells and lead to the development of drug resistance. Hence, the incorporation of DCX into various nanocarrier systems has garnered a significant amount of attention in recent years to overcome these drawbacks. The surfaces of these drug-delivery systems indeed can be functionalized by modification with different ligands for smart targeting towards cancerous cells. This article provides an overview of the latest nanotechnological approaches and the delivery systems that were developed for passive and active delivery of DCX via different routes of administration for the treatment of lung cancer.

Effect of ultrasonic irradiation power on sonochemical synthesis of gold nanoparticles

In this work, optimized size distribution and optical properties in the colloidal synthesis of gold nanoparticles (GNPs) were obtained using a proposed ultrasonic irradiation assisted Turkevich-Frens method. The effect of three nominal ultrasound (20 kHz) irradiation powers: 60, 150, and 210 W have been analyzed as size and shape control parameters. The GNPs colloidal solutions were obtained from chloroauric acid (HAuCl₄) and trisodium citrate (C₆H₅Na₃O₇·2H₂O) under continuous irradiation for 1 h without any additional heat or stirring. The surface plasmon resonance (SPR) was monitored in the UV-Vis spectra every 10 min to found the optimal time for localized SPR wavelength (λ_LSPR), and the 210 sample procedure has reduced the λ_LSPR localization at 20 min, while 150 and 60 samples have showed λ_LSPR at 60 min. The nucleation and growth of GNPs showed changes in shape and size distribution associated with physical (cavitation, temperature) and chemical (radical generation, pH) conditions in the aqueous solution. The results showed quasi-spherical GNPs as pentakis dodecahedron (λ_LSPR = 560 nm), triakis icosahedron (λ_LSPR = 535 nm), and tetrakis hexahedron (λ_LSPR = 525 nm) in a size range from 12 to 16 nm. Chemical effects of ultrasound irradiation were suggested in the disproportionation process, electrons of AuCl₂^- are rapidly exchanged through the gold surface. After AuCl₄^- and Cl^- were desorbed, a tetrachloroaurate complex was recycled for the two-electron reduction by citrate, aurophilic interaction between complexes AuCl₂^-, electrons exchange, and gold seeds, the deposition of new gold atoms on the surface promoting the growth of GNPs. These mechanisms are enhanced by the effects of ultrasound, such as cavitation and transmitted energy into the solution. These results show that the plasmonic response from the reported GNPs can be tuned using a simple methodology with minimum infrastructure requirements. Moreover, the production method could be easily scalable to meet industrial manufacturing needs.

Gold nanoparticle-mediated bubbles in cancer nanotechnology

Microbubbles (MBs) have been extensively investigated in the field of biomedicine for the past few decades. Ultrasound and laser are the most frequently used sources of energy to produce MBs. Traditional acoustic methods induce MBs with poor localized areas of action. A high energy level is required to generate MBs through the focused continuous laser, which can be harmful to healthy tissues. As an alternative, plasmonic light-responsive nanoparticles, such as gold nanoparticles (AuNPs), are preferably used with continuous laser to decrease the energy threshold and reduce the bubbles area of action. It is also well-known that the utilization of the pulsed lasers instead of the continuous lasers decreases the needed AuNPs doses as well as laser power threshold. When well-confined bubbles are generated in biological environments, they play their own unique mechanical and optical roles. The collapse of a bubble can mechanically affect its surrounding area. Such a capability can be used for cargo delivery to cancer cells and cell surgery, destruction, and transfection. Moreover, the excellent ability of light scattering makes the bubbles suitable for cancer imaging. This review firstly provides an overview of the fundamental aspects of AuNPs-mediated bubbles and then their emerging applications in the field of cancer nanotechnology will be reviewed. Although the pre-clinical studies on the AuNP-mediated bubbles have shown promising data, it seems that this technique would not be applicable to every kind of cancer. The clinical application of this technique may basically be limited to the good accessible lesions like the superficial, intracavity and intraluminal tumors. The other essential challenges against the clinical translation of AuNP-mediated bubbles are also discussed.

Functional Application of Sulfur-Containing Spice Compounds

Sulfur-containing spice compounds possess diverse biological functions and play an important role in food, chemicals, pharmaceuticals, and agriculture. The development of functional spices has become increasingly popular, especially for medicinal functions for dietary health. Thus, this review focuses on the properties and functions of sulfur-containing spice compounds, including antioxidant, anti-inflammatory, antiobesity, anticancer, antibacterial, and insecticidal functions, among others. Developments over the last five years concerning the properties of sulfur-containing spice compounds are summarized and discussed.

Rosin-based chiral wormlike Micelles: Rheological behavior and its application in preparing ultrasmall gold nanoparticles

Innovations in surfactant structures are a feasible way to prepare unique molecular aggregates with interesting properties. Herein, taking dehydroabietic acid as the starting material, a new amine oxide surfactant, abbreviated as R-8-AO, was synthesized. Cryogenic transmission electron microscopy (cryo-TEM) images and circular dichroism (CD) spectra reveal that at suitable concentrations, R-8-AO molecules form rarely discovered right-handed chiral wormlike micelles, which have a cross-sectional diameter of 5-6 nm. The overlap concentration of R-8-AO is approximately 8 mM, above which the wormlike micelles began to entangle in solutions. Due to the strong van der Waals forces between R-8-AO molecules, the scaling law gives an exponent of 7.88, which is higher than the theory predicted value. Gold nanoparticles were synthesized in-situ by irradiating mixed solutions of HAuCl₄ and wormlike micelles formed by R-8-AO with UV light. These ultrasmall spherical gold nanoparticles, which are located at the surface of wormlike micelles, have a uniform particle size of 3 ± 1 nm, as observed by TEM. In addition, the gold nanoparticles form a worm-like morphology induced by the wormlike micelles, showing soft-aggregate-directed nanoparticle assembly. This work is first to reveal the effectiveness of preparing ultrasmall gold nanoparticles with new morphological wormlike micelles as soft templates. The resulting organic-inorganic hybrid aggregates are also expected to find applications in catalysis and electronic fields.

Applications and challenges of thermoplasmonics

Over the past two decades, there has been a growing interest in the use of plasmonic nanoparticles as sources of heat remotely controlled by light, giving rise to the field of thermoplasmonics. The ability to release heat on the nanoscale has already impacted a broad range of research activities, from biomedicine to imaging and catalysis. Thermoplasmonics is now entering an important phase: some applications have engaged in an industrial stage, while others, originally full of promise, experience some difficulty in reaching their potential. Meanwhile, innovative fundamental areas of research are being developed. In this Review, we scrutinize the current research landscape in thermoplasmonics, with a specific focus on its applications and main challenges in many different fields of science, including nanomedicine, cell biology, photothermal and hot-electron chemistry, solar light harvesting, soft matter and nanofluidics.

Advances in Gold Nanoparticle-Based Combined Cancer Therapy

According to the global cancer observatory (GLOBOCAN), there are approximately 18 million new cancer cases per year worldwide. Cancer therapies are largely limited to surgery, radiotherapy, and chemotherapy. In radiotherapy and chemotherapy, the maximum tolerated dose is presently being used to treat cancer patients. The integrated development of innovative nanoparticle (NP) based approaches will be a key to address one of the main issues in both radiotherapy and chemotherapy: normal tissue toxicity. Among other inorganic NP systems, gold nanoparticle (GNP) based systems offer the means to further improve chemotherapy through controlled delivery of chemotherapeutics, while local radiotherapy dose can be enhanced by targeting the GNPs to the tumor. There have been over 20 nanotechnology-based therapeutic products approved for clinical use in the past two decades. Hence, the goal of this review is to understand what we have achieved so far and what else we can do to accelerate clinical use of GNP-based therapeutic platforms to minimize normal tissue toxicity while increasing the efficacy of the treatment. Nanomedicine will revolutionize future cancer treatment options and our ultimate goal should be to develop treatments that have minimum side effects, for improving the quality of life of all cancer patients.

Energy-converting biomaterials for cancer therapy: Category, efficiency, and biosafety

Energy-converting biomaterials (ECBs)-mediated cancer-therapeutic modalities have been extensively explored, which have achieved remarkable benefits to overwhelm the obstacles of traditional cancer-treatment modalities. Energy-driven cancer-therapeutic modalities feature their distinctive merits, including noninvasiveness, low mammalian toxicity, adequate therapeutic outcome, and optimistical synergistic therapeutics. In this advanced review, the prevailing mainstream ECBs can be divided into two sections: Reactive oxygen species (ROS)-associated energy-converting biomaterials (ROS-ECBs) and hyperthermia-related energy-converting biomaterials (H-ECBs). On the one hand, ROS-ECBs can transfer exogenous or endogenous energy (such as light, radiation, ultrasound, or chemical) to generate and release highly toxic ROS for inducing tumor cell apoptosis/necrosis, including photo-driven ROS-ECBs for photodynamic therapy, radiation-driven ROS-ECBs for radiotherapy, ultrasound-driven ROS-ECBs for sonodynamic therapy, and chemical-driven ROS-ECBs for chemodynamic therapy. On the other hand, H-ECBs could translate the external energy (such as light and magnetic) into heat for killing tumor cells, including photo-converted H-ECBs for photothermal therapy and magnetic-converted H-ECBs for magnetic hyperthermia therapy. Additionally, the biosafety issues of ECBs are expounded preliminarily, guaranteeing the ever-stringent requirements of clinical translation. Finally, we discussed the prospects and facing challenges for constructing the new-generation ECBs for establishing intriguing energy-driven cancer-therapeutic modalities. This article is categorized under: Nanotechnology Approaches to Biology >Nanoscale Systems in Biology.