Photothermal enhancement of chemotherapy in breast cancer by visible irradiation of Gold Nanoparticles

Tailoring Plasmonic Nanoheaters Size for Enhanced Theranostic Agent Performance

The introduction of optimized nanoheaters, which function as theranostic agents integrating both diagnostic and therapeutic processes, holds significant promise in the medical field. Therefore, developing strategies for selecting and utilizing optimized plasmonic nanoheaters is crucial for the effective use of nanostructured biomedical agents. This work elucidates the use of the Joule number (Jo) as a figure of merit to identify high-performance plasmonic theranostic agents. A framework for optimizing metallic nanoparticles for heat generation was established, uncovering the size dependence of plasmonic nanoparticles optical heating. Gold nanospheres (AuNSs) with a diameter of 50 nm and gold nanorods (AuNRs) with dimensions of 41×10 nm were identified as effective nanoheaters for visible (530 nm) and infrared (808 nm) excitation. Notably, AuNRs achieve higher Jo values than AuNSs, even when accounting for the possible orientations of the nanorods. Theoretical results estimate that 41×10 nm gold nanorods have an average Joule number of 80, which is significantly higher compared to larger rods. The photothermal performance of optimal and suboptimal nanostructures was evaluated using photoacoustic imaging and photothermal therapy procedures. The photoacoustic images indicate that, despite having larger absorption cross-sections, the large nanoparticle volume of bigger particles leads to less efficient conversion of light into heat, which suggests that the use of optimized nanoparticles promotes higher contrast, benefiting photoacoustic-based procedures in diagnostic applications. The photothermal therapy procedure was performed on S180-bearing mice inoculated with 41×10 nm and 90×25 nm PEGylated AuNRs. Five minutes of laser irradiation of tumor tissue with 41×10 nm produced an approximately 9.5% greater temperature rise than using 90×25 AuNRs in the therapy trials. Optimizing metallic nanoparticles for heat generation may reduce the concentration of the nanoheaters used or decrease the light fluence for bioscience applications, paving the way for the development of more economical theranostic agents.

Strategic Developments in Polymer-Functionalized Liposomes for Targeted Colon Cancer Therapy: An Updated Review of Clinical Trial Data and Future Horizons

Liposomes, made up of phospholipid bilayers, are efficient nanocarriers for drug delivery because they can encapsulate both hydrophilic and lipophilic drugs. Conventional cancer treatments sometimes involve considerable toxicities and adverse drug reactions (ADRs), which limits their clinical value. Despite liposomes' promise in addressing these concerns, clinical trials have revealed significant limitations, including stability, targeted distribution, and scaling challenges. Recent clinical trials have focused on enhancing liposome formulations to increase therapeutic efficacy while minimizing negative effects. Notably, the approval of liposomal medications like Doxil demonstrates their potential in cancer treatment. However, the intricacy of liposome preparation and the requirement for comprehensive regulatory approval remain substantial impediments. Current clinical trial updates show continued efforts to improve liposome stability, targeting mechanisms, and payload capacity in order to address these issues. The future of liposomal drug delivery in cancer therapy depends on addressing these challenges in order to provide patients with more effective and safer treatment alternatives.

Nanoparticle-mediated photoporation - an emerging versatile physical drug delivery method

Facilitating the delivery of impermeable molecules into cells stands as a pivotal step for both basic research and therapeutic delivery. While current methods predominantly use nanoparticles or viral vectors, the exploration of physical phenomena, particularly light-based techniques, remains relatively under-explored. Photoporation, a physical method, employs either pulsed or continuous wave lasers to create transient pores in cell membranes. These openings enable the entry of exogenous, membrane-impermeable molecules into the cytosol while preserving cell viability. Poration can either be achieved directly through focusing a laser beam onto a cell membrane, or indirectly through the addition of sensitizing nanoparticles that interact with the laser pulses. Nanoparticle-mediated photoporation specifically has recently been receiving increasing attention for the high-throughput ability to transfect cells, which also has exciting potential for clinical translation. Here, we begin with a snapshot of the current state of direct and indirect photoporation and the mechanisms that contribute to cell pore formation and molecule delivery. Following this, we present an outline of the evolution of photoporation methodologies for mammalian and non-mammalian cells, accompanied by a description of variations in experimental setups among photoporation systems. Finally, we discuss the potential clinical translation of photoporation and offer our perspective on recent key findings in the field, addressing unmet needs, gaps, and inconsistencies.

Preadsorbed Chymotrypsin Modulated the Composition of Protein Corona and Immunological Response

It is well-known that proteins after administration into biological environments adsorb on the surface of nanoparticles (NPs). The biological identity could be determined by protein corona, but whether and how the preadsorbed molecules impact the composition of the corona and immunological response have rarely been reported. Here, the effects of preadsorbed chymotrypsin (Chy) on forming protein corona and subsequent immunological response are reported. We find that preadsorbed Chy on the surface of AuNPs results in a protein corona with enriched immunoglobulins and reduced human serum albumin protein, which further affect the polarization of macrophages into specific phenotypes. Our study suggests that the protein surrounding the nanoparticles could affect the protein corona and immunological response, which may direct the preparation of multifunctional nanomedicine for future studies.

Diagnosis and treatment status of inoperable locally advanced breast cancer and the application value of inorganic nanomaterials

Locally advanced breast cancer (LABC) is a heterogeneous group of breast cancer that accounts for 10-30% of breast cancer cases. Despite the ongoing development of current treatment methods, LABC remains a severe and complex public health concern around the world, thus prompting the urgent requirement for innovative diagnosis and treatment strategies. The primary treatment challenges are inoperable clinical status and ineffective local control methods. With the rapid advancement of nanotechnology, inorganic nanoparticles (INPs) exhibit a potential application prospect in diagnosing and treating breast cancer. Due to the unique inherent characteristics of INPs, different functions can be performed via appropriate modifications and constructions, thus making them suitable for different imaging technology strategies and treatment schemes. INPs can improve the efficacy of conventional local radiotherapy treatment. In the face of inoperable LABC, INPs have proposed new local therapeutic methods and fostered the evolution of novel strategies such as photothermal and photodynamic therapy, magnetothermal therapy, sonodynamic therapy, and multifunctional inorganic nanoplatform. This article reviews the advances of INPs in local accurate imaging and breast cancer treatment and offers insights to overcome the existing clinical difficulties in LABC management.

Current development of theragnostic nanoparticles for women's cancer treatment

In the biomedical industry, nanoparticles (NPs-exclusively small particles with size ranging from 1-100 nanometres) are recently employed as powerful tools due to their huge potential in sophisticated and enhanced cancer theragnostic (i.e. therapeutics and diagnostics). Cancer is a life-threatening disease caused by carcinogenic agents and mutation in cells, leading to uncontrolled cell growth and harming the body's normal functioning while affecting several factors like low levels of reactive oxygen species, hyperactive antiapoptotic mRNA expression, reduced proapoptotic mRNA expression, damaged DNA repair, and so on. NPs are extensively used in early cancer diagnosis and are functionalized to target receptors overexpressing cancer cells for effective cancer treatment. This review focuses explicitly on how NPs alone and combined with imaging techniques and advanced treatment techniques have been researched against 'women's cancer' such as breast, ovarian, and cervical cancer which are substantially occurring in women. NPs, in combination with numerous imaging techniques (like PET, SPECT, MRI, etc) have been widely explored for cancer imaging and understanding tumor characteristics. Moreover, NPs in combination with various advanced cancer therapeutics (like magnetic hyperthermia, pH responsiveness, photothermal therapy, etc), have been stated to be more targeted and effective therapeutic strategies with negligible side effects. Furthermore, this review will further help to improve treatment outcomes and patient quality of life based on the theragnostic application-based studies of NPs in women's cancer treatment.

Biohybrid Flexible Sperm-like Microrobot for Targeted Chemo-Photothermal Therapy

Magnetic micro/nanorobots are promising platforms for targeted drug delivery, and their construction with soft and flexible features has received extensive attention for practical applications. Despite significant efforts in this field, facile fabrication of magnetic microrobots with flexible structures and versatility in targeted therapy remains a big challenge. Herein, we proposed a novel universal strategy to fabricate a biohybrid flexible sperm-like microrobot (BFSM) based on a Chlorella (Ch.) cell and artificial flagella, which showed great potential for targeted chemo-photothermal therapy for the first time. In this approach, microspherical Ch. cells were utilized to construct the microrobotic heads, which were intracellularly deposited with core-shell Pd@Au, extracellularly magnetized with Fe3O4, and further loaded with anticancer drug. The magnetic heads with excellent photothermal and chemotherapeutic capability were further assembled with flexible polypyrrole nanowires via biotin-streptavidin bonding to construct the BFSMs. Based on the exquisite head-to-tail structures, the BFSMs could be effectively propelled under precessing magnetic fields and move back and forth without a U-turn. Moreover, in vitro chemo-photothermal tests were conducted to verify their performance of targeted drug delivery toward localized HeLa cells. Due to this superior versatility and facile fabrication, the BFSMs demonstrated great potential for targeted anticancer therapy.

Niosomes containing paclitaxel and gold nanoparticles with different coating agents for efficient chemo/photothermal therapy of breast cancer

Breast cancer (BC) is one of the most common cancers in women, and chemotherapy is usually used to overcome this cancer. To improve drug delivery to cancer sites and reduce their side effects, nanocarriers such as niosomes (NIOs) are used. Moreover, a combination of other therapeutic methods like photothermal therapy (PTT) can help to enhance the chemotherapy effect. The aim of this research is the design a nanocarrier that simultaneously delivers chemotherapy and PTT agents. To achieve this goal, NIOs containing paclitaxel (PTX) as a chemotherapeutic agent and spherical gold nanoparticles (AuNPs) coated with citrate, chitosan (CS), and polyamidoamine (PAMAM) as a PTT agent were synthesized by thin hydration methods. Their physicochemical properties were determined by dynamic light scattering, UV-Vis, Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) analysis. Cellular uptake, cell cytotoxicity, hyperthermia, and apoptosis effects of the proposed system were investigated in the MCF-7 BC cell line. The cellular uptake of NIOs/AuNPs-PAMAM (99.21%) and NIOs/AuNPs-CS (98.93%) by MCF-7 cells was higher than that of NIOs/AuNPs (79.55%), demonstrating that surface charge plays a key role in the cellular uptake of NPs. The MTT assay showed the cell viability of 45.48% for NIOs/AuNPs/PTX, 34.24% for NIOs/AuNPs-CS/PTX, and 37.67% for NIOs/AuNPs-PAMAM/PTX after 48 h of treatment. However, the application of hyperthermia significantly decreased the viability of cells treated with NIOs/AuNPs/PTX (37.72%), NIOs/AuNPs-CS/PTX (10.49%), and NIOs/AuNPs-PAMAM/PTX (4.1%) after 48 h. The apoptosis rate was high in NIOs/AuNPs-PAMAM/PTX (53.24%) and NIOs/AuNPs-CS/PTX (55.4%) confirming the data from MTT. In conclusion, the result revealed that combined PTT with chemotherapy increased cell cytotoxicity effects against the MCF-7 cells, and the AuNPs with various coating agents affected cellular uptake and hyperthermia which can be considered for efficient BC therapy.

Nanomaterials-assisted photothermal therapy for breast cancer: State-of-the-art advances and future perspectives

Breast cancer (BC) remains an enigmatic fatal modality ubiquitously prevalent in different parts of the world. Contemporary medicines face severe challenges in remediating and healing breast cancer. Due to its spatial specificity and nominal invasive therapeutic regime, photothermal therapy (PTT) has attracted much scientific attention down the lane. PTT utilizes a near-infrared (NIR) light source to irradiate the tumor target intravenously or non-invasively, which is converted into heat energy over an optical fibre. Dynamic progress in nanomaterial synthesis was achieved with specialized visual, physicochemical, biological, and pharmacological features to make up for the inadequacies and expand the horizon of PTT. Numerous nanomaterials have substantial NIR absorption and can function as efficient photothermal transducers. It is achievable to limit the wavelength range of an absorbance peak for specific nanomaterials by manipulating their synthesis, enhancing the precision and quality of PTT. Along the same lines, various nanomaterials are conjugated with a wide range of surface-modifying chemicals, including polymers and antibodies, which may modify the persistence of the nanomaterial and diminish toxicity concerns. In this article, we tend to put forth specific insights and fundamental conceptualizations on pre-existing PTT and its advances upon conjugation with different biocompatible nanomaterials working in synergy to combat breast cancer, encompassing several strategies like immunotherapy, chemotherapy, photodynamic therapy, and radiotherapy coupled with PTT. Additionally, the role or mechanisms of nanoparticles, as well as possible alternatives to PTT, are summarized as a distinctive integral aspect in this article.

Graphene Oxide (GO) for the Treatment of Bone Cancer: A Systematic Review and Bibliometric Analysis

Cancer is a severe disease that, in 2022, caused more than 9.89 million deaths worldwide. One worrisome type of cancer is bone cancer, such as osteosarcoma and Ewing tumors, which occur more frequently in infants. This study shows an active interest in the use of graphene oxide and its derivatives in therapy against bone cancer. We present a systematic review analyzing the current state of the art related to the use of GO in treating osteosarcoma, through evaluating the existing literature. In this sense, studies focused on GO-based nanomaterials for potential applications against osteosarcoma were reviewed, which has revealed that there is an excellent trend toward the use of GO-based nanomaterials, based on their thermal and anti-cancer activities, for the treatment of osteosarcoma through various therapeutic approaches. However, more research is needed to develop highly efficient localized therapies. It is suggested, therefore, that photodynamic therapy, photothermal therapy, and the use of nanocarriers should be considered as non-invasive, more specific, and efficient alternatives in the treatment of osteosarcoma. These options present promising approaches to enhance the effectiveness of therapy while also seeking to reduce side effects and minimize the damage to surrounding healthy tissues. The bibliometric analysis of photothermal and photochemical treatments of graphene oxide and reduced graphene oxide from January 2004 to December 2022 extracted 948 documents with its search strategy, mainly related to research papers, review papers, and conference papers, demonstrating a high-impact field supported by the need for more selective and efficient bone cancer therapies. The central countries leading the research are the United States, Iran, Italy, Germany, China, South Korea, and Australia, with strong collaborations worldwide. At the same time, the most-cited papers were published in journals with impact factors of more than 6.0 (2021), with more than 290 citations. Additionally, the journals that published the most on the topic are high impact factor journals, according to the analysis performed, demonstrating the high impact of the research field.

Nano-phototherapy: Favorable prospects for cancer treatment

Nanotechnology-based phototherapies have drawn interest in the fight against cancer because of its noninvasiveness, high flexibility, and precision in terms of cancer targeting and drug delivery based on its surface properties and size. Phototherapy has made remarkable development in recent decades. Approaches to phototherapy, which utilize nanomaterials or nanotechnology have emerged to contribute to advances around nanotechnologies in medicine, particularly for cancers. A brief overviews of the development of photodynamic therapy as well as its mechanism in cancer treatment is provided. We emphasize the design of novel nanoparticles utilized in photodynamic therapy while summarizing the representative progress during the recent years. Finally, to forecast important future research in this area, we examine the viability and promise of photodynamic therapy systems based on nanoparticles in clinical anticancer treatment applications and briefly make mention of the elimination of all reactive metabolites pertaining to nano formulations inside living organisms providing insight into clinical mechanistic processes. Future developments and therapeutic prospects for photodynamic treatments are anticipated. Our viewpoints might encourage scientists to create more potent phototherapy-based cancer therapeutic modalities. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

TACkling Cancer by Targeting Selective Protein Degradation

Targeted protein degradation has emerged as an alternative therapy against cancer, offering several advantages over traditional inhibitors. The new degrader drugs provide different therapeutic strategies: they could cross the phospholipid bilayer membrane by the addition of specific moieties to extracellular proteins. On the other hand, they could efficiently improve the degradation process by the generation of a ternary complex structure of an E3 ligase. Herein, we review the current trends in the use of TAC-based technologies (TACnologies), such as PROteolysis TArgeting Chimeras (PROTAC), PHOtochemically TArgeting Chimeras (PHOTAC), CLIck-formed Proteolysis TArgeting Chimeras (CLIPTAC), AUtophagy TArgeting Chimeras (AUTAC), AuTophagosome TEthering Compounds (ATTEC), LYsosome-TArgeting Chimeras (LYTAC), and DeUBiquitinase TArgeting Chimeras (DUBTAC), in experimental development and their progress towards clinical applications.

Unveiling the mechanisms underlying photothermal efficiency of gold shell-isolated nanoparticles (AuSHINs) on ductal mammary carcinoma cells (BT-474)

Gold nanoparticles are valuable photothermal agents owing to their efficient photothermal conversion, photobleaching resistance, and potential surface functionalization. Herein, we combined bioinspired membranes with in vitro assays to elicit the molecular mechanisms of gold shell-isolated nanoparticles (AuSHINs) on ductal mammary carcinoma cells (BT-474). Langmuir and Langmuir-Schaefer (LS) films were handled to build biomembranes from BT-474 lipid extract. AuSHINs incorporation led to surface pressure-area (π-A) isotherms expansion, increasing membrane flexibility. Fourier-transform infrared spectroscopy (FTIR) of LS multilayers revealed electrostatic AuSHINs interaction with head portions of BT-474 lipid extract, causing lipid chain disorganization. Limited AuSHINs insertion into monolayer contributed to hydroperoxidation of the unsaturated lipids upon irradiation, consistently with the surface area increments of ca. 2.0%. In fact, membrane disruption of irradiated BT-474 cells containing AuSHINs was confirmed by confocal microscopy and LDH leakage, with greater damage at 2.2 × 1013 AuSHINs/mL. Furthermore, the decrease in nuclei dimensions indicates cell death through photoinduced damage.

Gold Nanoparticles Functionalized with 2-Thiouracil for Antiproliferative and Photothermal Therapies in Breast Cancer Cells

Nanoparticles have been used to transport drugs to various body parts to treat cancer. Our interest is in gold nanoparticles (AuNPs) since they have the capacity to absorb light and convert it to heat, inducing cellular damage. This property is known as photothermal therapy (PTT) and has been studied in cancer treatment. In the present study, biocompatible citrate-reduced AuNPs were functionalized with a biologically active compound, 2-thiouracil (2-TU), of potential anticancer activity. Both the unfunctionalized (AuNPs) and functionalized (2-TU-AuNPs) were purified and characterized by UV-Vis absorption spectrophotometry, Zeta potential, and Transmission Electron Microscopy. Results showed monodispersed, spherical AuNPs with a mean core diameter of 20 ± 2 nm, a surface charge of -38 ± 5 mV, and a localized surface plasmon resonance peak at 520 nm. As a result of functionalization, the mean core diameter of 2-TU-AuNPs increased to 24 ± 4 nm, and the surface charge increased to -14 ± 1 mV. The functionalization of AuNPs and the load efficiency were further established through Raman spectroscopy and UV-Vis absorption spectrophotometry. The antiproliferative activities of AuNPs, 2-TU and 2-TU-AuNPs were examined by a 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay in the MDA-MB-231 breast cancer cell line. It was established that AuNPs significantly enhanced the antiproliferative activity of 2-TU. Furthermore, the irradiation of the samples with visible light at 520 nm decreased the half-maximal inhibitory concentration by a factor of 2. Thus, the 2-TU drug concentration and its side effect during treatments could be significantly reduced by synergistically exploiting the antiproliferative activity of 2-TU loaded onto AuNPs and the PTT effect of AuNPs.

Photothermal treatment of glioblastoma cells based on plasmonic nanoparticles

Photothermal therapy based on plasmonic gold nanoparticles is considered a promising approach for cancer treatment. Here, we investigate the in vitro photothermal effect of 30-nm gold nanoparticles, optically excited with a 532-nm continuous laser, on the U87MG malignant glioblastoma cells, and demonstrate the role of nanoparticle concentration and exposure power density in achieving its optimum performance. Laser-induced collective oscillation of electrons in plasmonic gold nanoparticles is employed to generate localized heat to denature tumor cells. Optical spectroscopy is used to measure the plasmonic band of nanoparticles and select the excitation laser light. The MTT assay for the IC50 viability assessment is performed to evaluate the live and metabolically active cells after treatment with plasmonic nanoparticles. The quantitative data is statistically analyzed using analysis of variance followed by Tukey's post hoc test. The viability test demonstrates that the metabolic activity of treated U87MG was decreased compared with untreated cells, leading to the determination of the IC50 as 92 [Formula: see text]. A 532-nm laser light was selected for the excitation of gold nanoparticles since the maximum plasmonic band is at 524 nm. The viability tests show that although cells have natural photothermal agents, their absorption efficiency is very low; therefore, the laser-induced plasmonic effect is necessary to observe photothermal effects. The optimal condition was achieved when the nanoparticle concentration was 92 [Formula: see text], and the exposure power density was 96 [Formula: see text]. Thus, it is demonstrated that plasmonic nanoparticle concentration and laser exposure power density are among the key parameters in the photothermal treatment of cancer cells, and higher concentrations of Au-NPs and laser power density lead to less cell viability in the selected range due to the excitation of gold nanoparticles' localized surface plasmon resonance.

Safety of Gold Nanoparticles: From In Vitro to In Vivo Testing Array Checklist

In recent years, gold nanoparticles (AuNPs) have aroused the interest of many researchers due to their unique physicochemical and optical properties. AuNPs are being explored in a variety of biomedical fields, either in diagnostics or therapy, particularly for localized thermal ablation of cancer cells after light irradiation. Besides the promising therapeutic potential of AuNPs, their safety constitutes a highly important issue for any medicine or medical device. For this reason, in the present work, the production and characterization of physicochemical properties and morphology of AuNPs coated with two different materials (hyaluronic and oleic acids (HAOA) and bovine serum albumin (BSA)) were firstly performed. Based on the above importantly referred issue, the in vitro safety of developed AuNPs was evaluated in healthy keratinocytes, human melanoma, breast, pancreatic and glioblastoma cancer cells, as well as in a three-dimensional human skin model. Ex vivo and in vivo biosafety assays using, respectively, human red blood cells and Artemia salina were also carried out. HAOA-AuNPs were selected for in vivo acute toxicity and biodistribution studies in healthy Balb/c mice. Histopathological analysis showed no significant signs of toxicity for the tested formulations. Overall, several techniques were developed in order to characterize the AuNPs and evaluate their safety. All these results support their use for biomedical applications.

Carbon Dots: Opportunities and Challenges in Cancer Therapy

Recently, carbon dots (CDs) have been actively studied and reported for their various properties. In particular, the specific characteristics of carbon dots have been considered as a possible technique for cancer diagnosis and therapy. This is also a cutting-edge technology that offers fresh ideas for treating various disorders. Though carbon dots are still in their infancy and have not yet shown their value to society, their discovery has already resulted in some noteworthy advancements. The application of CDs indicates conversion in natural imaging. Photography using CDs has demonstrated extraordinary appropriateness in bio-imaging, the discovery of novel drugs, the delivery of targeted genes, bio-sensing, photodynamic therapy, and diagnosis. This review seeks to provide a comprehensive understanding of CDs, including their benefits, characteristics, applications, and mode of action. In this overview, many CD design strategies will be highlighted. In addition, we will discuss numerous studies on cytotoxic testing to demonstrate the safety of CDs. The current study will address the production method, mechanism, ongoing research, and application of CDs in cancer diagnosis and therapy.

Inorganic Nanomaterials Used in Anti-Cancer Therapies:Further Developments

In this article, we provide an overview of the progress of scientists working to improve the quality of life of cancer patients. Among the known methods, cancer treatment methods focusing on the synergistic action of nanoparticles and nanocomposites have been proposed and described. The application of composite systems will allow precise delivery of therapeutic agents to cancer cells without systemic toxicity. The nanosystems described could be used as a high-efficiency photothermal therapy system by exploiting the properties of the individual nanoparticle components, including their magnetic, photothermal, complex, and bioactive properties. By combining the advantages of the individual components, it is possible to obtain a product that would be effective in cancer treatment. The use of nanomaterials to produce both drug carriers and those active substances with a direct anti-cancer effect has been extensively discussed. In this section, attention is paid to metallic nanoparticles, metal oxides, magnetic nanoparticles, and others. The use of complex compounds in biomedicine is also described. A group of compounds showing significant potential in anti-cancer therapies are natural compounds, which have also been discussed.

Neoadjuvant Gold Nanoshell-Based Photothermal Therapy Combined with Liposomal Doxorubicin in a Mouse Model of Colorectal Cancer

Introduction

Traditional cancer treatments, such as chemotherapy, are often incapable of achieving complete responses as standalone therapies. Hence, current treatment strategies typically rely on a combination of several approaches. Nanoparticle-based photothermal therapy (PTT) is a technique used to kill cancer cells through localized, severe hyperthermia that has shown promise as an add-on treatment to multiple cancer therapies. Here, we evaluated whether the combination of gold nanoshell (NS)-based PTT and liposomal doxorubicin could improve outcome in a mouse model of colorectal cancer.

Methods

First, NS-based PTT was performed on tumor-bearing mice. Radiolabeled liposomes were then injected at different timepoints to follow their accumulation in the tumor and determine the ideal injection time after PTT. In addition, fluorescent liposomes were used to observe the liposomal distribution in the tumor after PTT. Finally, we combined PTT and doxorubicin-loaded liposomes and studied the effect of the treatment strategy on the mice by following tumor growth and survival.

Results

PTT significantly improved liposomal accumulation in the tumor, but only when the liposomes were injected immediately after the therapy. The liposomes accumulated mostly in regions adjacent to the ablated areas. When PTT was combined with liposomal doxorubicin, the mice experienced a slowdown in tumor growth and an improvement in survival.

Conclusion

According to our preclinical study, NS-based PTT seems promising as an add-on treatment for liposomal chemotherapy and potentially other systemic therapies, and could be relevant for future application in a clinical setting.

Triphenylphosphonium conjugated gold nanotriangles impact Pi3K/AKT pathway in breast cancer cells: a photodynamic therapy approach

Although gold nanoparticles based photodynamic therapy (PDT) were reported to improve efficacy and specificity, the impact of surface charge in targeting cancer is still a challenge. Herein, we report gold nanotriangles (AuNTs) tuned with anionic and cationic surface charge conjugating triphenylphosphonium (TPP) targeting breast cancer cells with 5-aminoleuvinic acid (5-ALA) based PDT, in vitro. Optimized surface charge of AuNTs with and without TPP kill breast cancer cells. By combining, 5-ALA and PDT, the surface charge augmented AuNTs deliver improved cellular toxicity as revealed by MTT, fluorescent probes and flow cytometry. Further, the 5-ALA and PDT treatment in the presence of AuNTs impairs cell survival Pi3K/AKT signaling pathway causing mitochondrial dependent apoptosis. The cumulative findings demonstrate that, cationic AuNTs with TPP excel selective targeting of breast cancer cells in the presence of 5-ALA and PDT.

Bioactive Polymeric Nanoparticles of Moringa oleifera Induced Phyto-Photothermal Sensitization for the Enhanced Therapy of Retinoblastoma

Treatment of retinoblastoma is limited due to its delayed detection and inaccesbility of drugs to reach the retina crossing the blood-retinal barrier. With the advancements in nanotechnology, photothermal therapy (PTT) employing plasmonic nanomaterials and/or NIR dyes have emerged as an affordable alternative owing to the spatial control that is offered by the modality leading to localized and enhanced therapeutic efficacy with minimal invasiveness. However, the modality is limited in its clinical application owing to the increased heat shock resistance of the tumor cells in response to the heat that is generated via PTT. Hence, in this study, we explore the role of novel biomolecular fraction of Moringa oleifera (DFM) encapsulated within a polymeric nanosystem, for its anti-heat shock protein (HSP) activity. The MO extract was co-encapsulated with NIR sensitizing dye, IR820 into a biodegradable polycaprolactone (PCL) nano-delivery system (PMIR NPs). The photothermal transduction efficacy of PMIR NPs was validated in vitro against retinoblastoma cell lines. The inherent fluorescence of DFM was utilized to evaluate the cellular internalization of the PMIR NPs using fluorescence microscopy and flow cytometry. The overall oxidative protein damage and downregulation of HSP70 expression upon treatment with PMIR NPs and NIR laser irradiation was evaluated using densiometric protein analysis and Western blotting. Overall, the PMIR NPs exhibited excellent anti-cancer activity when combined with PTT with downregulated HSP70 expression against retinoblastoma cells.

Self-assembled amphiphilic copolymers-doxorubicin conjugated nanoparticles for gastric cancer therapy with low in vivo toxicity and high efficacy

Amphiphilic copolymers have long been utilized to turn hydrophobic anticancer drugs into nanoparticles administered to patients with cancer. A lack of stability in these monotherapies may be blamed for their poor clinical results in patients with cancer. We propose novel nanotherapies based on polymeric small prodrugs that preserve pharmacologic effectiveness while significantly reducing the toxicity of the fabricated drugs in animals to overcome this problem. Doxorubicin is attached to the end of the PLA fragments through a hydrolyzable ester bond utilizing methoxypolyethylene glycol-block-poly(d, l-lactic acid) (mPEG-PCL(2K)) with conjugates to mimic the self-assembly of colloidal nanotherapies. In a gastric cancer xenograft model, this nanotherapy displays a long-lasting suppression of tumor growth once a reasonable dosage is administered. Our findings imply that a toxic chemical and hydrophobic can be converted into therapeutic effective self-delivery nanotreatment.

Membrane-wrapped nanoparticles for photothermal cancer therapy

Cancer is a global health problem that needs effective treatment strategies. Conventional treatments for solid-tumor cancers are unsatisfactory because they cause unintended harm to healthy tissues and are susceptible to cancer cell resistance. Nanoparticle-mediated photothermal therapy is a minimally invasive treatment for solid-tumor cancers that has immense promise as a standalone therapy or adjuvant to other treatments like chemotherapy, immunotherapy, or radiotherapy. To maximize the success of photothermal therapy, light-responsive nanoparticles can be camouflaged with cell membranes to endow them with unique biointerfacing capabilities that reduce opsonization, prolong systemic circulation, and improve tumor delivery through enhanced passive accumulation or homotypic targeting. This ensures a sufficient dose of photoresponsive nanoparticles arrives at tumor sites to enable their complete thermal ablation. This review summarizes the state-of-the-art in cell membrane camouflaged nanoparticles for photothermal cancer therapy and provides insights to the path forward for clinical translation.

Recent advances in nanoparticle-based photothermal therapy for breast cancer

Breast cancer is one of the most common cancers among women that is associated with high mortality. Conventional treatments including surgery, radiotherapy, and chemotherapy, which are not effective enough and have disadvantages such as toxicity and damage to healthy cells. Photothermal therapy (PTT) of cancer cells has been took great attention by researchers in recent years due to the use of light radiation and heat generation at the tumor site, which thermal ablation is considered a minimally invasive method for the treatment of breast cancer. Nanotechnology has opened up a new perspective in the treatment of breast cancer using PTT method. Through NIR light absorption, researchers applied various nanostructures because of their specific nature of penetrating and targeting tumor tissue, increasing the effectiveness of PTT, and combining it with other treatments. If PTT is used with common cancer treatments, it can dramatically increase the effectiveness of treatment and reduce the side effects of other methods. PTT performance can also be improved by hybridizing at least two different nanomaterials. Nanoparticles that intensely absorb light and increase the efficiency of converting light into heat can specifically kill tumors through hyperthermia of cancer cells. One of the main reasons that have increased the efficiency of nanoparticles in PTT is their permeability and durability effect and they can accumulate in tumor tissue. Targeted PTT can be provided by incorporating specific ligands to target receptors expressed on the surface of cancer cells on nanoparticles. These nanoparticles can specifically target cancer cells by maintaining the surface area and increasing penetration. In this study, we briefly introduce the performance of light therapy, application of metal nanoparticles, polymer nanoparticles, carbon nanoparticles, and hybrid nanoparticles for use in PTT of breast cancer.

Two Methods of AuNPs Synthesis Induce Differential Vascular Effects. The Role of the Endothelial Glycocalyx

AuNPs are synthesized through several methods to tune their physicochemical properties. Although AuNPs are considered biocompatible, a change in morphology or properties can modify their biological impact. In this work, AuNPs (~12 to 16 nm) capping with either sodium citrate (CA) or gallic acid (GA) were evaluated in a rat aorta ex vivo model, which endothelial inner layer surface is formed by glycocalyx (hyaluronic acid, HA, as the main component), promoting vascular processes, most of them dependent on nitric oxide (NO) production. Results showed that contractile effects were more evident with AuNPsCA, while dilator effects predominated with AuNPsGA. Furthermore, treatments with AuNPsCA and AuNPsGA in the presence or absence of glycocalyx changed the NO levels, differently. This work contributes to understanding the biological effects of AuNPs with different capping agents, as well as the key role that of HA in the vascular effects induced by AuNPs in potential biomedical applications.

Laser Synthesized Core-Satellite Fe-Au Nanoparticles for Multimodal In Vivo Imaging and In Vitro Photothermal Therapy

Hybrid multimodal nanoparticles, applicable simultaneously to the noninvasive imaging and therapeutic treatment, are highly demanded for clinical use. Here, Fe-Au core-satellite nanoparticles prepared by the method of pulsed laser ablation in liquids were evaluated as dual magnetic resonance imaging (MRI) and computed tomography (CT) contrast agents and as sensitizers for laser-induced hyperthermia of cancer cells. The biocompatibility of Fe-Au nanoparticles was improved by coating with polyacrylic acid, which provided excellent colloidal stability of nanoparticles with highly negative ζ-potential in water (−38 ± 7 mV) and retained hydrodynamic size (88 ± 20 nm) in a physiological environment. The ferromagnetic iron cores offered great contrast in MRI images with r₂ = 11.8 ± 0.8 mM⁻¹ s⁻¹ (at 1 T), while Au satellites showed X-ray attenuation in CT. The intravenous injection of nanoparticles enabled clear tumor border visualization in mice. Plasmonic peak in the Fe-Au hybrids had a tail in the near-infrared region (NIR), allowing them to cause hyperthermia under 808 nm laser exposure. Under NIR irradiation Fe-Au particles provided 24.1 °C/W heating and an IC₅₀ value below 32 µg/mL for three different cancer cell lines. Taken together, these results show that laser synthesized Fe-Au core-satellite nanoparticles are excellent theranostic agents with multimodal imaging and photothermal capabilities.

Multifunctional Gold Nanoparticles in Cancer Diagnosis and Treatment

Cancer is the second leading cause of death in the world, behind only cardiovascular diseases, and is one of the most serious diseases threatening human health nowadays. Cancer patients’ lives are being extended by the use of contemporary medical technologies, such as surgery, radiotherapy, and chemotherapy. However, these treatments are not always effective in extending cancer patients’ lives. Simultaneously, these approaches are often accompanied with a series of negative consequences, such as the occurrence of adverse effects and an increased risk of relapse. As a result, the development of a novel cancer-eradication strategy is still required. The emergence of nanomedicine as a promising technology brings a new avenue for the circumvention of limitations of conventional cancer therapies. Gold nanoparticles (AuNPs), in particular, have garnered extensive attention due to their many specific advantages, including customizable size and shape, multiple and useful physicochemical properties, and ease of functionalization. Based on these characteristics, many therapeutic and diagnostic applications of AuNPs have been exploited, particularly for malignant tumors, such as drug and nucleic acid delivery, photodynamic therapy, photothermal therapy, and X-ray-based computed tomography imaging. To leverage the potential of AuNPs, these applications demand a comprehensive and in-depth overview. As a result, we discussed current achievements in AuNPs in anticancer applications in a more methodical manner in this review. Also addressed in depth are the present status of clinical trials, as well as the difficulties that may be encountered when translating some basic findings into the clinic, in order to serve as a reference for future studies.

Light Triggered Enhancement of Antibiotic Efficacy in Biofilm Elimination Mediated by Gold-Silver Alloy Nanoparticles

Bacterial biofilm is a tri-dimensional complex community of cells at different metabolic stages involved in a matrix of self-produced extracellular polymeric substances. Biofilm formation is part of a defense mechanism that allows the bacteria to survive in hostile environments, such as increasing resistance or tolerance to antimicrobial agents, causing persistent infections hard to treat and impair disease eradication. One such example is bovine mastitis associated with Streptococcus dysgalactiae subsp. dysgalactiae (SDSD), whose worldwide health and economic impact is on the surge. As such, non-conventional nanobased approaches have been proposed as an alternative to tackle biofilm formation and to which pathogenic bacteria fail to adapt. Among these, metallic nanoparticles have gained significant attention, particularly gold and silver nanoparticles, due to their ease of synthesis and impact against microorganism growth. This study provides a proof-of-concept investigation into the use of gold-silver alloy nanoparticles (AuAgNPs) toward eradication of bacterial biofilms. Upon visible light irradiation of AuAgNPs there was considerable disturbance of the biofilms' matrix. The hindering of structural integrity of the biofilm matrix resulted in an increased permeability for entry of antibiotics, which then cause the eradication of biofilm and inhibit subsequent biofilm formation. Additionally, our results that AuAgNPs inhibited the formation of SDSD biofilms via distinct stress pathways that lead to the downregulation of two genes critical for biofilm production, namely, brpA-like encoding biofilm regulatory protein and fbpA fibronectin-binding protein A. This study provides useful information to assist the development of nanoparticle-based strategies for the active treatment of biofilm-related infections triggered by photoirradiation in the visible.

Novel Green Approaches for the Preparation of Gold Nanoparticles and Their Promising Potential in Oncology

The difficulty of achieving targeted drug delivery following administration of currently marketed anticancer therapeutics is a still a concern. Metallic nanoparticles (NPs) developed through nanotechnology breakthroughs appear to be promising in this regard. Research studies pertaining to gold NPs have indicated their promising applicability in cancer diagnosis, drug delivery and therapy. These NPs have also recently paved the path for precise drug delivery and site-specific targeting. Our review paper thus highlights the scope and impact of biogenetically generated gold nanoparticles (NPs) in cancer therapy. In a critical, constructive, and methodical manner, we compare the advantages offered by gold NPs over other metal NPs. Moreover, we also focus on novel ‘greener’ strategies that have been recently explored for the preparation of gold NPs and shed light on the disadvantages of conventional NP synthesis routes. Future prospects pertaining to the use of gold NPs in oncotherapy and domains that require further investigation are also addressed.

Deducing the cellular mechanisms associated with the potential genotoxic impact of gold and silver engineered nanoparticles upon different lung epithelial cell lines in vitro

Human ENP exposure is inevitable and the novel, size-dependent physicochemical properties that enable ENPs to be beneficial in innovative technologies are concomitantly causing heightened public concerns as to their potential adverse effects upon human health. This study aims to deduce the mechanisms associated with potential ENP mediated (geno)toxicity and impact upon telomere integrity, if any, of varying concentrations of both ∼16 nm (4.34 × 10^-3 to 17.36 × 10^-3mg/mL) Gold (Au) and ∼14 nm (0.85 × 10^-5 to 3.32 × 10^-5mg/mL) Silver (Ag) ENPs upon two commonly used lung epithelial cell lines, 16HBE14o^- and A549. Following cytotoxicity analysis (via Trypan Blue and Lactate Dehydrogenase assay), two sub-lethal concentrations were selected for genotoxicity analysis using the cytokinesis-blocked micronucleus assay. Whilst both ENP types induced significant oxidative stress, Ag ENPs (1.66 × 10^-5mg/mL) did not display a significant genotoxic response in either epithelial cell lines, but Au ENPs (8.68 × 10^-3mg/mL) showed a highly significant 2.63-fold and 2.4-fold increase in micronucleus frequency in A549 and 16HBE14o^- cells respectively. It is hypothesized that the DNA damage induced by acute 24-h Au ENP exposure resulted in a cell cycle stall indicated by the increased mononuclear cell fraction (>6.0-fold) and cytostasis level. Albeit insignificant, a small reduction in telomere length was observed following acute exposure to both ENPs which could indicate the potential for ENP mediated telomere attrition. Finally, from the data shown, both in vitro lung cell cultures (16HBE14o^- and A549) are equally as suitable and reliable for the in vitro ENP hazard identification approach adopted in this study.

Dendrimer-Based Nanogels for Cancer Nanomedicine Applications

Recent advances in the field of nanotechnology bring an alternative approach to personalized medicine in cancer treatment. Nanogels (NGs) are among the nanosized superconstructs composed of amphiphilic or hydrophilic polymer networks. The design of different types of biodegradable polymer-based NGs in various biomedical applications has received extensive attention, due to their unique physicochemical properties such as highly porous structure, stimuli-responsiveness, and mimicking of some biological properties. In this review, we concisely surveyed the synthesis of dendrimer-based NGs synthesized via different methods including covalent conjugation, inverse nanoprecipitation, physical cross-linking, or self-assembly for various cancer nanomedicine applications, particularly for drug delivery, gene delivery, photothermal therapy, and combination therapy, as well as for biological imaging-guided chemotherapy. Additionally, we provide herein future perspective toward the new design of dendrimer-based NGs for different cancer nanomedicine uses.

Multifunctional Polymeric Nanoparticles for Chemo/Phototheranostics of Retinoblastoma

Retinoblastoma (Rb) is the most critical and severe intraocular malignancy occurring in children. The clinical management of retinoblastoma is still challenging due to failure in early detection and control despite the advancements in medical strategies. Early-stage Rb tumors do not occupy major visual fields, so chemo/photothermal therapy (PTT) with biocompatible materials can be a practical approach. Herein, we report multifunctional polymeric nanoparticles (PNPs) entrapped with an FDA-approved anticancer drug, Palbociclib (PCB), and a near-infrared dye, IR820 (IR), as chemo/photothermal agents. These PCB/IR PNPs were evaluated for the combinational effect in the retinoblastoma cell line. Further, the in vivo photoacoustic imaging efficacy and acute toxicity profile of the PNPs were studied in a mice model. The results indicated that the PCB/IR PNPs exhibited a significant cytotoxic effect (86.5 ± 2.3%) in Y79 cell lines than the respective control groups upon exposure to NIR light. Qualitative and quantitative analyses indicated that PCB/IR PNPs with NIR light induction resulted in DNA damage followed by apoptosis. PCB/IR PNPs, when tested in vivo, showed optimal photoacoustic signals. Thus, the combination of PCB and PTT can emerge as a translational modality for retinoblastoma therapy.

The efficiency of photothermal action of gold shell-isolated nanoparticles against tumor cells depends on membrane interactions

Photoinduced hyperthermia with nanomaterials has been proven effective in photothermal therapy (PTT) of tumor tissues, but a precise control in PTT requires determination of the molecular-level mechanisms. In this paper, we determined the mechanisms responsible for the action of photoexcited gold shell-isolated nanoparticles (AuSHINs) in reducing the viability of MCF7 (glandular breast cancer) and especially A549 (lung adenocarcinoma) cells in vitro experiments, while the photoinduced damage to healthy cells was much smaller. The photoinduced effects were more significant than using other nanomaterials, and could be explained by the different effects from incorporating AuSHINs on Langmuir monolayers from lipid extracts of tumoral (MCF7 and A549) and healthy cells. The incorporation of AuSHINs caused similar expansion of the Langmuir monolayers, but Fourier-transform infrared spectroscopy (FTIR) data of Langmuir-Schaefer films (LS) indicated distinct levels of penetration into the monolayers. AuSHINs penetrated deeper into the A549 extract monolayers, affecting the vibrational modes of polar groups and carbon chains, while in MCF7 monolayers penetration was limited to the surroundings of the polar groups. Even smaller insertion was observed for monolayers of the healthy cell extract. The photochemical reactions were modulated by AuSHINs penetration, since upon irradiation the surface area of A549 monolayer decreased owing to lipid chain cleavage by oxidative reactions. For MCF7 monolayers, hydroperoxidation under illumination led to a ca. 5% increase in surface area. The monolayers of healthy cell lipid extract were barely affected by irradiation, consistent with the lowest degree of AuSHINs insertion. In summary, efficient photothermal therapy may be devised by producing AuSHINs capable of penetrating the chain region of tumor cell membranes.

Nanogold-based materials in medicine: from their origins to their future

The properties of gold-based materials have been explored for centuries in several research fields, including medicine. Multiple published production methods for gold nanoparticles (AuNPs) have shown that the physicochemical and optical properties of AuNPs depend on the production method used. These different AuNP properties have allowed exploration of their usefulness in countless distinct biomedical applications over the last few years. Here we present an extensive overview of the most commonly used AuNP production methods, the resulting distinct properties of the AuNPs and the potential application of these AuNPs in diagnostic and therapeutic approaches in biomedicine.

Multifunctional Gold Nanoparticles for Improved Diagnostic and Therapeutic Applications: A Review

The medical properties of metals have been explored for centuries in traditional medicine for the treatment of infections and diseases and still practiced to date. Platinum-based drugs are the first class of metal-based drugs to be clinically used as anticancer agents following the approval of cisplatin by the United States Food and Drug Administration (FDA) over 40 years ago. Since then, more metals with health benefits have been approved for clinical trials. Interestingly, when these metals are reduced to metallic nanoparticles, they displayed unique and novel properties that were superior to their bulk counterparts. Gold nanoparticles (AuNPs) are among the FDA-approved metallic nanoparticles and have shown great promise in a variety of roles in medicine. They were used as drug delivery, photothermal (PT), contrast, therapeutic, radiosensitizing, and gene transfection agents. Their biomedical applications are reviewed herein, covering their potential use in disease diagnosis and therapy. Some of the AuNP-based systems that are approved for clinical trials are also discussed, as well as the potential health threats of AuNPs and some strategies that can be used to improve their biocompatibility. The reviewed studies offer proof of principle that AuNP-based systems could potentially be used alone or in combination with the conventional systems to improve their efficacy.

Nanoparticle Systems for Cancer Phototherapy: An Overview

Photodynamic therapy (PDT) and photothermal therapy (PTT) are photo-mediated treatments with different mechanisms of action that can be addressed for cancer treatment. Both phototherapies are highly successful and barely or non-invasive types of treatment that have gained attention in the past few years. The death of cancer cells because of the application of these therapies is caused by the formation of reactive oxygen species, that leads to oxidative stress for the case of photodynamic therapy and the generation of heat for the case of photothermal therapies. The advancement of nanotechnology allowed significant benefit to these therapies using nanoparticles, allowing both tuning of the process and an increase of effectiveness. The encapsulation of drugs, development of the most different organic and inorganic nanoparticles as well as the possibility of surfaces' functionalization are some strategies used to combine phototherapy and nanotechnology, with the aim of an effective treatment with minimal side effects. This article presents an overview on the use of nanostructures in association with phototherapy, in the view of cancer treatment.

Laser photo-thermal therapy of epithelial carcinoma using pterin-6-carboxylic acid conjugated gold nanoparticles

Gold nanoparticles functionalized with folic acid toward the internalization into cancer cells have received considerable attention recently. Folic acid is recognized by folate receptors, which are overexpressed in several cancer cells; it is limited in normal cells. In this work, pterin-6-carboxylic acid is proposed as an agonist of folic acid since the pterin-6-carboxylic acid structure has a pterin moiety, the same as folic acid that is recognized by the folate receptor. Here a simple photochemical synthesis of gold nanoparticles functionalized with pterin-6-carboxylic acid is studied. These conjugates were used to cause photothermal damage of HeLa cells irradiating with a diode laser of 808 nm. Pterin-6-carboxylic acid-conjugated gold nanoparticles caused the death of the cell after near-infrared irradiation, dose-dependently. These results indicate a possible internalization of AuNPs via folate receptor-mediated endocytosis due to the recognition or interaction between the folate receptors of HeLa cells and pterin, P6CA.

Magnetic mediators for ultrasound theranostics

The theranostics paradigm is based on the concept of combining therapeutic and diagnostic modalities into one platform to improve the effectiveness of treatment. Combinations of multiple modalities provide numerous medical advantages and are enabled by nano- and micron-sized mediators. Here we review recent advancements in the field of ultrasound theranostics and the use of magnetic materials as mediators. Several subdisciplines are described in detail, including controlled drug delivery and release, ultrasound hyperthermia, magneto-ultrasonic heating, sonodynamic therapy, magnetoacoustic imaging, ultrasonic wave generation by magnetic fields, and ultrasound tomography. The continuous progress and improvement in theranostic materials, methods, and physical computing models have created undeniable possibilities for the development of new approaches. We discuss the prospects of ultrasound theranostics and possible expansions of other studies to the theranostic context.

Polarization-dependent plasmonic nano-tweezer as a platform for on-chip trapping and manipulation of virus-like particles

Plasmonics advanced materials with the capability of environmental variation detection extend the application of visible light, satisfying the demands of less footprint, easy-to-use, and high tunability for visible-sensitive materials. In this area, localized surface plasmon can significantly enhance the electric field smaller than the radiation wavelength providing a strong gradient force required in optical tweezing systems. Owing to this beneficial advantage over the conventional optical tweezers, the plasmonic tweezers have matured to a stage where today become increasingly attractive for trapping and manipulation of nanoparticles. In this work, we are proposing a tunable plasmonic nano-tweezer that operates according to the polarization of excitation laser light. The proposed novel structure encompasses a gold nano-ring and a gold nano-disk in which by changing the beam polarization, the hot spots position also changes, and the nanoparticles can be relocated around the circumference of a circle trapped at a certain point. According to 3D finite-difference-time-domain simulations, the proposed nano-tweezing system can potentially exert a trapping force of 164 pNW-1 on a 20 nm HIV-1 virus-like particle.

Green Metallic Nanoparticles for Cancer Therapy: Evaluation Models and Cancer Applications

Metal-based nanoparticles are widely used to deliver bioactive molecules and drugs to improve cancer therapy. Several research works have highlighted the synthesis of gold and silver nanoparticles by green chemistry, using biological entities to minimize the use of solvents and control their physicochemical and biological properties. Recent advances in evaluating the anticancer effect of green biogenic Au and Ag nanoparticles are mainly focused on the use of conventional 2D cell culture and in vivo murine models that allow determination of the half-maximal inhibitory concentration, a critical parameter to move forward clinical trials. However, the interaction between nanoparticles and the tumor microenvironment is not yet fully understood. Therefore, it is necessary to develop more human-like evaluation models or to improve the existing ones for a better understanding of the molecular bases of cancer. This review provides recent advances in biosynthesized Au and Ag nanoparticles for seven of the most common and relevant cancers and their biological assessment. In addition, it provides a general idea of the in silico, in vitro, ex vivo, and in vivo models used for the anticancer evaluation of green biogenic metal-based nanoparticles.

Gas Sensors Based on Localized Surface Plasmon Resonances: Synthesis of Oxide Films with Embedded Metal Nanoparticles, Theory and Simulation, and Sensitivity Enhancement Strategies

This work presents a comprehensive review on gas sensors based on localized surface plasmon resonance (LSPR) phenomenon, including the theory of LSPR, the synthesis of nanoparticle-embedded oxide thin films, and strategies to enhance the sensitivity of these optical sensors, supported by simulations of the electromagnetic properties. The LSPR phenomenon is known to be responsible for the unique colour effects observed in the ancient Roman Lycurgus Cup and at the windows of the medieval cathedrals. In both cases, the optical effects result from the interaction of the visible light (scattering and absorption) with the conduction band electrons of noble metal nanoparticles (gold, silver, and gold–silver alloys). These nanoparticles are dispersed in a dielectric matrix with a relatively high refractive index in order to push the resonance to the visible spectral range. At the same time, they have to be located at the surface to make LSPR sensitive to changes in the local dielectric environment, the property that is very attractive for sensing applications. Hence, an overview of gas sensors is presented, including electronic-nose systems, followed by a description of the surface plasmons that arise in noble metal thin films and nanoparticles. Afterwards, metal oxides are explored as robust and sensitive materials to host nanoparticles, followed by preparation methods of nanocomposite plasmonic thin films with sustainable techniques. Finally, several optical properties simulation methods are described, and the optical LSPR sensitivity of gold nanoparticles with different shapes, sensing volumes, and surroundings is calculated using the discrete dipole approximation method.

A Study on Improving the Efficacy of Nanoparticle-Based Photothermal Therapy: From Nanoscale to Micron Scale to Millimeter Scale

Photothermal therapy based on nanoparticles is a promising method for cancer treatment. However, there are still many limits in practical application. During photothermal therapy, improving therapeutic effect is contradictory to reducing overheating in healthy tissues. We should make the temperature distribution more uniform and reduce the damage of healthy tissue caused by overheating. In the present work, we develop a simple computational method to analyze the temperature distribution during photothermal therapy at three levels (nanoscale, micron scale, and millimeter scale), and investigate the effects of nanoparticle size, volume fraction, light intensity, and irradiation shape on temperature distribution. We find that it is difficult to achieve good therapeutic effect just by adjusting the volume fraction of nanoparticles and light intensity. To achieve good therapeutic effect, we propose a new irradiation shape, spot array light. This method can achieve a better temperature distribution by easily regulating the positions of spots for the tumor with a large aspect ratio or a small one. In addition, the method of irradiation with spot array light can better reduce the overheating at the bottom and top of the tumor than the full-coverage light or others such as ring light. This theoretical work presents a simple method to investigate the effects of irradiation shape on therapy and provides a far more controlled way to improve the efficacy of photothermal therapy.

Gold Nanoparticles- Boon in Cancer Theranostics

BACKGROUND

Cancer is the world's second-largest cause of death, with an estimated 9.6 million fatalities in 2018. Malignant tumour (cancer) is caused by a mixture of genetic modifications due to the environmental variables that tend to activate or inactivate different genes, ultimately resulting in neoplastic transformations. Cancer is a multi-stage process that results from the conversion of the ordinary cells to tumour cells and progresses from a pre-cancer lesion to abnormal growth.

METHODS

Chemotherapy inhibits the ability of the cells to divide rapidly in an abnormal manner, but this treatment simultaneously affects the entire cellular network in the human body leading to cytotoxic effects. In this review article, the same issue has been addressed by discussing various aspects of the newer class of drugs in cancer therapeutics, i.e., Gold Nanoparticles (AuNPs) from metal nanoparticle (NP) class.

RESULTS

Metal NPs are advantageous over conventional chemotherapy as the adverse drug reactions are lesser. Additionally, ease of drug delivery, targeting and gene silencing are salient features of this treatment. Functionalized ligand-targeting metal NPs provide better energy deposition control in tumour. AuNPs are promising agents in the field of cancer treatment and are comprehensively studied as contrast agents, carriers of medicinal products, radiosensitizers and photothermal agents. For the targeted delivery of chemotherapeutic agents, AuNPs are used and also tend to enhance tumour imaging in vivo for a variety of cancer types and diseased organs.

CONCLUSION

The first part of the review focuses on various nano-carriers that are used for cancer therapy and deals with the progression of metal NPs in cancer therapy. The second part emphasizes the use of nanotechnology by considering the latest studies for diagnostic and therapeutic properties of AuNPs. AuNPs present the latest studies in the field of nanotechnology, which leads to the development of early-stage clinical trials. The next part of the review discusses the major features of five principal types of AuNPs: gold nanorods, gold nanoshells, gold nanospheres, gold nanocages, and gold nanostars that have their application in photothermal therapy (PTT).

Gold nanoparticle-mediated generation of reactive oxygen species during plasmonic photothermal therapy: a comparative study for different particle sizes, shapes, and surface conjugations

Gold nanoparticle (AuNP)-mediated photothermal therapy represents an alternative to the effective ablation of cancer cells. However, the photothermal response of AuNPs must be tailored to improve the therapeutic efficacy of plasmonic photothermal therapy (PPT) and mitigate its side effects. This study presents an alternative to ease the tuning of photothermal efficiency and target selectivity. We use laser-treated spherical and anisotropic AuNPs of different sizes and biocompatible folic acid (FA)-conjugated AuNPs (FA-AuNPs) in the well-known human epithelial cervical cancer (HeLa) cell line. We show that large AuNPs produce a more significant photothermal heating effect than small ones. The thermal response of the spherical AuNPs of 9 nm was found to reach a maximum increase of 3.0 ± 1 °C, whereas with the spherical AuNPs of 14 nm, the temperature increased by over 4.4 ± 1 °C. The anisotropic AuNPs of 15 nm reached a maximum of 4.0 ± 1 °C, whereas the anisotropic AuNPs of 20 nm reached a significant increase of 5.3 ± 1 °C in the cell culture medium (MEM). Notably, the anisotropic AuNPs of 20 nm successfully demonstrate the potential for use as a photothermal agent by showing reduced viability down to 60% at a concentration of 100 μM. Besides, we reveal that high concentrations of reactive oxygen species (ROS) are formed within the irradiated cells. In combination with stress by photothermal heating, it is likely to result in significant cell death through acute necrosis by compromising the plasma membrane integrity. Cell death and ROS overproduction during PPT were characterized and quantified by transmission electron microscopy (TEM) and confocal fluorescence microscopy with different fluorescent markers. In addition, we show that FA-AuNPs induce cell death through apoptosis by internal damage, whereas diminish the ROS formation during PPT treatment. Our findings suggest the ability of plasmon-mediated ROS to sensitize cancer cells and make them vulnerable to photothermal damage, as well as the protective role of FA-AuNPs from excessive ROS formation, whereas reducing the risk of undesired side effects due to the necrotic death pathway. It allows an improvement in the efficacy of the AuNP-based photothermal therapy and a reduction in the number of exposures to high temperatures required to induce thermal stress.