Gold nanoparticles as novel agents for cancer therapy

Functionalized Nanomaterials in Cancer Treatment: A Review

Cancer is one of the main causes of death worldwide. Chemotherapy, radiotherapy and surgery are currently the treatments of choice for cancer. However, conventional therapies have their limitations, such as non-specificity, tumor recurrence and toxicity to the target cells. Recently, nanomaterials have been considered as therapeutic agents against cancer. This is mainly due to their unique optical properties, biocompatibility, large surface area and nanoscale size. These properties are crucial as they can affect biocompatibility and uptake by the cell, reducing efficacy. However, because nanoparticles can be functionalized with biomolecules, they become more biocompatible, which improves uptake, and they can be specifically targeted against cancer cells, which improves their anticancer activity. In this review, we summarize some of the recent studies in which nanomaterials have been functionalized with the aim of increasing therapeutic efficacy in cancer treatment.

Inorganic Nanomaterials Meet the Immune System: An Intricate Balance

The immune system provides defense against foreign agents that are considered harmful for the organism. Inorganic nanomaterials can be recognized by the immune system as antigens, inducing an immune reaction dependent on the patient's immunological anamnesis and from several factors including size, shape, and the chemical nature of the nanoparticles. Furthermore, nanomaterials-driven immunomodulation might be exploited for therapeutic purposes, opening new horizons in oncology and beyond. In this scenario, we present a critical review of the state of the art regarding the preclinical evaluation of the effects of the most promising metals for biomedical applications (gold, silver, and copper) on the immune system. Because exploiting the interactions between the immune system and inorganic nanomaterials may result in a game changer for the management of (non)communicable diseases, within this review we encounter the need to summarize and organize the plethora of sometimes inconsistent information, analyzing the challenges and providing the expected perspectives. The field is still in its infancy, and our work emphasizes that a deep understanding on the influence of the features of metal nanomaterials on the immune system in both cultured cells and animal models is pivotal for the safe translation of nanotherapeutics to the clinical practice.

Navigating Tumor Microenvironment Barriers with Nanotherapeutic Strategies for Targeting Metastasis

Therapeutic strategy for efficiently targeting cancer cells needs an in-depth understanding of the cellular and molecular interplay in the tumor microenvironment (TME). TME comprises heterogeneous cells clustered together to translate tumor initiation, migration, and proliferation. The TME mainly comprises proliferating tumor cells, stromal cells, blood vessels, lymphatic vessels, cancer-associated fibroblasts (CAFs), extracellular matrix (ECM), and cancer stem cells (CSC). The heterogeneity and genetic evolution of metastatic tumors can substantially impact the clinical effectiveness of therapeutic agents. Therefore, the therapeutic strategy shall target TME of all metastatic stages. Since the advent of nanotechnology, smart drug delivery strategies are employed to deliver effective drug formulations directly into tumors, ensuring controlled and sustained therapeutic efficacy. The state-of-the-art nano-drug delivery systems are shown to have innocuous modes of action in targeting the metastatic players of TME. Therefore, this review provides insight into the mechanism of cancer metastasis involving invasion, intravasation, systemic transport of circulating tumor cells (CTCs), extravasation, metastatic colonization, and angiogenesis. Further, the novel perspectives associated with current nanotherapeutic strategies are highlighted on different stages of metastasis.

Synergistic Nanoformulation: Streamlined One-Pot Synthesis Enhances Paclitaxel Functionalization Gold Nanoparticles for Potent Anticancer Activity

The development of innovative, eco-friendly methods for synthesizing functional nanoparticles is crucial in advancing cancer therapeutics. This study highlights a one-pot in situ synthesis of paclitaxel-functionalized gold nanoparticles (PTX-AuNPs), with paclitaxel serving as both the reducing and stabilizing agent. The synthesis process was validated using UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and high-resolution transmission electron microscopy (FEG-TEM). High-performance liquid chromatography (HPLC) confirmed the purity and structural integrity of paclitaxel before and after synthesis. The resulting PTX-AuNPs exhibited potent anticancer activity against human cervical cancer (SiHa) and human colon cancer (HT-29) cell lines, with a significantly stronger effect on the HT-29 cell line. A concentration-dependent reduction in HT-29 cell growth was observed as nanoparticle concentrations increased from 10 µg/mL-20 µg/mL. Molecular docking studies further demonstrated paclitaxel's strong binding affinity (-8.5 kcal/mol) to β-Tubulin, elucidating its anticancer mechanism. This cost-effective and environmentally friendly approach offers significant promise for enhancing cancer treatment strategies.

An Evaluation of the Potential Radiosensitization Effect of Spherical Gold Nanoparticles to Induce Cellular Damage Using Different Radiation Qualities

Global disparities in cancer prevention, detection, and treatment demand a unified international effort to reduce the disease's burden and improve outcomes. Despite advances in chemotherapy and radiotherapy, many tumors remain resistant to these treatments. Gold nanoparticles (AuNPs) have shown promise as radiosensitizers, enhancing the effectiveness of low-energy X-rays by emitting Auger electrons that cause localized cellular damage. In this study, spherical AuNPs of 5 nm and 10 nm were characterized and tested on various cell lines, including malignant breast cells (MCF-7), non-malignant cells (CHO-K1 and MCF-10A), and human lymphocytes. Cells were treated with AuNPs and irradiated with attenuated 6 megavoltage (MV) X-rays or p(66)/Be neutron radiation to assess DNA double-strand break (DSB) damage, cell viability, and cell cycle progression. The combination of AuNPs and neutron radiation induced higher levels of γ-H2AX foci and micronucleus formation compared to treatments with AuNPs or X-ray radiation alone. AuNPs alone reduced cellular kinetics and increased the accumulation of cells in the G2/M phase, suggesting a block of cell cycle progression. For cell proliferation, significant effects were only observed at the concentration of 50 μg/mL of AuNPs, while lower concentrations had no inhibitory effect. Further research is needed to quantify internalized AuNPs and correlate their concentration with the observed cellular effects to unravel the biological mechanisms of their radioenhancement.

Emerging Role of Hypoxia-Inducible Factors (HIFs) in Modulating Autophagy: Perspectives on Cancer Therapy

Hypoxia-inducible factors (HIFs) are master regulators of cellular responses to low oxygen levels and modulate autophagy, a conserved process essential for maintaining homeostasis. Under hypoxic conditions, HIFs regulate the expression of autophagy-related genes and influence autophagic flux and cellular stress responses. Dysregulated hypoxia-induced autophagy promotes cancer cell survival, metabolism, and metastasis, thereby contributing to treatment resistance. Targeting HIF-mediated pathways or modulating autophagic processes offers the potential to improve traditional cancer therapies and overcome drug resistance. Pharmacological inhibitors of HIFs or autophagy, either alone or in combination with other treatments, may disrupt the pro-survival mechanisms within the hypoxic tumor microenvironment. Further research is needed to elucidate the intricate interplay between HIF signaling and the autophagy machinery in cancer cells. Understanding these processes could pave the way for novel therapeutic strategies to enhance treatment outcomes and combat drug resistance. This review highlights the complex relationship between HIFs and autophagy in cancer development and therapy, offering insights into how targeting these pathways may improve patient outcomes.

Recent advances in improved efficacies of gold nano-formulations in treatment of skin cancer: a systematic review

Skin cancer is the commonest malignancy for the population. Conventional skin cancer treatments include chemotherapy and surgery, but a large number of the chemotherapeutic drugs applied currently have undesirable possessions. The aim of this study is to provide a complete and acute assessment of the antitumor capability of gold nano-formulations in skin cancer as a new and more effectual delivery system for targeted therapy. In this systematic review, we conducted our first search in December 2021. In order to find related studies, 3 databases PubMed, Scopus and ScienceDirect. In order to maintain comprehensiveness in the search, no time limit was considered in the search process and finally the information obtained from the search was transferred to the information management software (EndNote). In order to maximize the number of articles that were related to our topic, a list of references identified in relevant articles was also manually searched and reviewed. Our final search was updated in late December 2021. There was evidence for a correlation between anticancer activities and treatment with gold nano-formulations. Additionally, studies shown that specific functionalization of the gold nanoparticles (Au NPs) which increase targetability to specific populations of cells could increase the application of Au NPs to the effective delivery of drugs to tumor cells. Our study demonstrated that gold nano-formulations are possible candidates for skin cancer treatment and might provide additional support for the clinical use of these anticancer agents in the future.

Characterization and evaluation of the cytotoxic, antioxidant, and anti-human lung cancer properties of copper nanoparticles green-synthesized by fennel extract following the PI3K/AKT/Mtor signaling pathway

This work established the cytotoxic, antioxidant and anticancer effects of copper nanoparticles (CuNPs) manufactured with fennel extract, especially on non-small cell lung cancer (NSCLC) as well. CuNPs caused cytotoxicity in a dose-dependent manner for two NSCLC cell lines, A549 and H1650. At 100 μg/ml, CuNPs reduced cell viability to 70% in A549 cells and 65% in H1650 cells. which showed a cytotoxic effect (p<0. 05). Lactate dehydrogenase (LDH) was correspondingly present in a high proportion in the cells, demonstrated upon testing. Together with their cytotoxic properties, CuNPs demonstrated high antioxidative activity. When the concentration of the nano particles was high (100 μg/ml), the ratio of reactive oxygen species (ROS) was reduced as much as 50%, which in turn suggested antioxidant activity. There was plenty of evidence that CuNPs had anti-cancer potential; this has been shown by the effect of the molecules on the PI3K/AKT/mTOR pathway, which was one of the pathways crucial for cancer survival. Western blot analysis and qRT-PCR results indicated a widespread degradation of the proteins in this pathway upon CuNP exposure. Interestingly, there was a declined phosphorylation up to 75% of PI3K, AKT, and mTOR at 100 μg/ml (p<0. 001). In summary, these findings illustrated the mechanisms behind the therapeutic effect of CuNPs, thus making them good targets for the NSCLC treatment. CuNPs have cytotoxic and antioxidant capacity, as well as significant alterations in lung cancers pathway, and therefore they can be considered as anti-cancer candidates.

Synthesis of Urchin-Like Au@TiO2 Nano-Carriers as a Drug-Loading System Toward Cancer Treatment

In recent years, improving the pharmaceutical properties of drug delivery for anti-cancer treatment has become increasingly important. This is necessary to address challenges related to absorption, distribution, and stability. One potential approach solution is to attach the drug to a carrier system, such as functional noble nanomaterials, in order to improve the control of drug release and stability. Core-satellite nanoparticles (CSN) with an anisotropic morphology have enormous potential for targeted drug delivery and cancer treatment because of their large surface area, exceptional stability, and biocompatibility. We used a simple seed-mediated approach to synthesize urchin-like gold nanoparticles (ULGNPs) with a high aspect ratio and a dense network of 49 nm-sized branches, using seed solution, silver nitrate, and ascorbic acid. The ULGNPs were synthesized without a surfactant and then encapsulated with thin layers of amorphous TiO2 (ULGNPs@TiO2), resulting in an average overall size of 136±15 nm with a 27.5 nm TiO2 layer. Doxorubicin (Dox) was chosen as a model drug to assess the distribution carrier ability of ULGNPs@TiO2 core-satellite nanoparticles. The results showed 86.5 % Dox loading and 72.3 % release capacity at pH 5. The anti-cancer ability of ULGNPs@TiO2-Dox was meticulously assessed using breast cancer MCF-7 cells in the WST-1 assay. The results revealed that ULGNPs@TiO2-Dox exhibited approximately 92 % toxicity in MCF-7 cells compared to the free Dox of 89.6 % at low concentrations (5 ppm). Based on the simulation results for loading ULGNPs@TiO2 with Dox, it was observed that a structure containing five layers of Au (111) with three fixed bottom layers and two relaxed top layers, in addition to six TiO2 (100) layers, was analyzed using Grimme's DFT-D3 dispersion corrections (Scheme 1). The density functional theory (DFT) adsorption energy (Eads) shows that the amorphous TiO2 increases the Dox loading activity of ULGNPs, with Eads=-3.85 eV, negatively higher than isolated ULGNPs (Eads=-2.87 eV) and TiO2 alone (Eads=-3.61 eV). This drug carrier design has the potential to revolutionize anti-cancer treatment.

Elevating Therapeutic Penetration: Innovations in Drug Delivery for Enhanced Permeation and Skin Cancer Management

Skin cancer stands as a challenging global health concern, necessitating innovative approaches to cure deficiencies within traditional therapeutic modalities. While conventional drug delivery methods through injection or oral administration have long prevailed, the emergence of topical drug administration presents a compelling alternative. The skin, aside from offering a swift and painless procedure, serves as a reservoir, maintaining drug efficacy over extended durations. This comprehensive review seeks to shed light on the potential of nanotechnology as a promising avenue for efficacious cancer treatment, with a particular emphasis on skin cancer. Additionally, it underscores the transdermal approach as a viable strategy for addressing various types of cancer. This work also explores into the delivery of peptides and proteins along with in-depth explanations of different delivery systems currently under investigation for localized skin cancer treatment. Furthermore, the review discusses the formidable challenges that must be surmounted before these innovations can find their way into clinical practice, offering a roadmap for future research and therapeutic development.

Recent Developments in Nanotechnology and Immunotherapy for the Diagnosis and Treatment of Pancreatic Cancer

Pancreatic cancer kills millions of people worldwide each year and is one of the most prevalent causes of mortality that requires prompt therapy. A large number of people suffering from pancreatic cancer are detected at an advanced stage, with incurable and drug-resistant tumor, hence the overall survival rate of pancreatic cancer is less. The advance phase of this cancer is generated because of expression of the cancer-causing gene, inactivation of the tumorsuppressing gene, and deregulation of molecules in different cellular signalling pathways. The prompt diagnosis through the biomarkers significantly evades the progress and accelerates the survival rates. The overexpression of Mesothelin, Urokinase plasminogen activator, IGFR, Epidermal growth factor receptor, Plectin-1, Mucin-1 and Zinc transporter 4 were recognized in the diagnosis of pancreatic cancer. Nanotechnology has led to the development of nanocarriersbased formulations (lipid, polymer, inorganic, carbon based and advanced nanocarriers) which overcome the hurdles of conventional therapy, chemotherapy and radiotherapy which causes toxicity to adjacent healthy tissues. The biocompatibility, toxicity and large-scale manufacturing are the hurdles associated with the nanocarriers-based approaches. Currently, Immunotherapybased techniques emerged as an efficient therapeutic alternative for the prevention of cancer. Immunological checkpoint targeting techniques have demonstrated significant efficacy in human cancers. Recent advancements in checkpoint inhibitors, adoptive T cell therapies, and cancer vaccines have shown potential in overcoming the immune evasion mechanisms of pancreatic cancer cells. Combining these immunotherapeutic approaches with nanocarriers holds great promise in enhancing the antitumor response and improving patient survival.

Femtosecond Laser-Induced Photothermal Effects of Ultrasmall Plasmonic Gold Nanoparticles on the Viability of Human Hepatocellular Carcinoma HepG2 Cells

Laser-induced photothermal therapy using gold nanoparticles (AuNPs) has emerged as a promising approach to cancer therapy. However, optimizing various laser parameters is critical for enhancing the photothermal conversion efficacy of plasmonic nanomaterials. In this regard, the present study investigates the photothermal effects of dodecanethiol-stabilized hydrophobic ultrasmall spherical AuNPs (TEM size 2.2 ± 1.1 nm), induced by a 343 nm wavelength ultrafast femtosecond-pulse laser with a low intensity (0.1 W/cm2) for 5 and 10 min, on the cell morphology and viability of human hepatocellular carcinoma (HepG2) cells treated in vitro. The optical microscopy images showed considerable alteration in the overall morphology of the cells treated with AuNPs and irradiated with laser light. Infrared thermometer measurements showed that the temperature of the cell medium treated with AuNPs and exposed to the laser increased steadily from 22 °C to 46 °C and 48.5 °C after 5 and 10 min, respectively. The WST-1 assay results showed a significant reduction in cell viability, demonstrating a synergistic therapeutic effect of the femtosecond laser and AuNPs on HepG2 cells. The obtained results pave the way to design a less expensive, effective, and minimally invasive photothermal approach to treat cancers with reduced side effects.

The application of cyclodextrins in drug solubilization and stabilization of nanoparticles for drug delivery and biomedical applications

Nanoparticles (NPs) have gained significant attention in recent years due to their potential applications in pharmaceutical formulations, drug delivery systems, and various biomedical fields. The versatility of colloidal NPs, including their ability to be tailored with various components and synthesis methods, enables drug delivery systems to achieve controlled release patterns, improved solubility, and increased bioavailability. The review discusses various types of NPs, such as nanocrystals, lipid-based NPs, and inorganic NPs (i.e., gold, silver, magnetic NPs), each offering unique advantages for drug delivery. Despite the promising potential of NPs, challenges such as physical instability and the need for surface stabilization remain. Strategies to overcome these challenges include the use of surfactants, polymers, and cyclodextrins (CDs). This review highlights the role of CDs in stabilizing colloidal NPs and enhancing drug solubility. The combination of CDs with NPs presents a synergistic approach that enhances drug delivery and broadens the range of biomedical applications. Additionally, the potential of CDs to enhance the stability and therapeutic efficacy of colloidal NPs, making them promising candidates for advanced drug delivery systems, is comprehensively reviewed.

Investigation of a broad diversity of nanoparticles, including their processes, as well as toxicity testing in diverse organs and systems

Nanotechnology arising in wide-ranging areas, covers extensively different ranges of approaches attained from fields such as biology, chemistry, physics, and medicine engineering. Nanoparticles are a necessary part of nanotechnology effectually applied in the cure of a number of diseases. Nanoparticles have gained significant importance due to their unique properties, which differ from their bulk counterparts. These distinct properties of nanoparticles are primarily influenced by their morphology, size, and size distribution. At the nanoscale, nanoparticles exhibit behaviours that can enhance therapeutic efficacy and reduce drug toxicity. Their small size and large surface area make them promising candidates for applications such as targeted drug delivery, where they can improve treatment outcomes while minimizing adverse effects. The harmful effects of nanoparticles on the environment were critically investigated to obtain appropriate results and reduce the risk by incorporating the materials. Nanoparticles tend to penetrate the human body, clear the biological barriers to reach sensitive organs and are easily incorporated into human tissue, as well as dispersing to the hepatic tissues, heart tissues, encephalum, and GI tract. This study aims to examine a wide variety of nanoparticles, focusing on their manufacturing methods, functional characteristics, and interactions within biological systems. Particular attention will be directed towards assessing the toxicity of nanoparticles in different organs and physiological systems, yielding a thorough comprehension of their potential health hazards and the processes that drive nanoparticle-induced toxicity. This analysis will also emphasize recent developments in nanoparticle applications and safety assessment methodologies.

Targeting Radiation Resistance in Oesophageal Adenocarcinoma with Pyrazinib-Functionalised Gold Nanoparticles

Background/Objectives: Only 20-30% of oesophageal adenocarcinoma (OAC) patients achieve a complete response to neoadjuvant chemo-radiotherapy for locally advanced tumours. Enhancing the response to radiation therapy is critical for improving outcomes in this aggressive cancer. Pyrazinib (P3) is a promising compound with radiosensitizing, anti-angiogenic, anti-inflammatory, and anti-metabolic properties. However, its limited solubility and bioavailability have hindered its therapeutic potential.

METHODS

To overcome these limitations, pyrazinib was conjugated with gold nanoparticles (AuNP-P3), creating a novel formulation designed to enhance solubility, maintain bioactivity, and enable targeted delivery to tumour sites.

RESULTS

In an isogenic model of OAC radioresistance, AuNP-P3 significantly reduced the surviving fraction following irradiation, demonstrating its radiosensitizing properties. It also reduced mitochondrial metabolism and modulated the secretion of inflammatory mediators in both in vitro models of OAC radioresistance and human ex vivo OAC tumour explants. Furthermore, AuNP-P3 exhibited potent anti-angiogenic activity, significantly inhibiting blood vessel formation in vivo using zebrafish embryo models.

CONCLUSIONS

These results collectively confirm that P3, in its conjugated formulation with gold nanoparticles, retains its therapeutic properties, highlighting the potential of AuNP-P3 as a novel therapeutic radiosensitizer for oesophageal adenocarcinoma and supporting its further development for clinical applications.

Salinity-responsive hyperaccumulation of flavonoids in Spirodela polyrrhiza, resultant maneuvering in the structure and antimicrobial as well as azo dye decontamination profile of biofabricated zinc oxide nanoentities

Duckweeds (Spirodela polyrrhiza) are free-floating macrophytes that grow profusely in nutrient-rich waters. Under ideal conditions, they exhibit a rapid growth rate and can absorb a substantial amount of nutrients, macromolecules, and pollutants from bodies of water. Zinc oxide nanoparticles (ZnO NPs) synthesized from plant extracts, particularly under stress conditions, have opened new research avenues in the field of nanotechnology. Under salinity stress, the accumulation of flavonoids in duckweeds can affect the structure of ZnO NPs, helping researchers ascertain their antimicrobial role. In our study, we exposed mid-log phase duckweed monocultures to 75 mM NaCl in a full-strength Murashige and Skoog medium for 7 days, followed by a 15-day recovery period. We observed significant overexpression of superoxide and hydrogen peroxide as reactive oxygen species. As a result, chlorophyll and certain metabolites were produced in lesser amounts, while flavonoid and phenol content increased by 12% and 8%, respectively. This overproduction persisted up to 10 days into the recovery treatment period but dropped by 8% and 5%, respectively, by the 15th day. The flavonoid coating transformed the NPs into rosette clusters, which exhibited reduced antimicrobial activity against Aeromonas hydrophila, a Gram-negative, fish-pathogenic bacterium. Herein, we discuss potential mechanisms for the conformational transformation of ZnO NPs into finer dimensions in response to NaCl-induced oxidative stress in duckweed. In this study, the azo dye degradation capacity of salinity-treated plants increased as the flavonoid profile became enriched. Zinc oxide nanoparticles, both prior to and after salinity treatment, were found to be efficient in scavenging azo dye and mitigating its toxicity, as evidenced by improved germination, growth, and overall plant morphometry.

Global research and current trends on nanotherapy in lung cancer research: a bibliometric analysis of 20 years

BACKGROUND

Lung cancer ranks as one of the most rapidly growing malignancies. Which is characterized by its poor prognosis and a low survival rate due to late diagnosis and limited efficacy of conventional treatments. In recent years nanotechnology has emerged as a promising frontier in the management of lung cancer, presenting novel strategies to enhance drug administration, improve therapeutic efficiency, and mitigate side effects. This research comprehensively evaluates the current state and research trends concerning the application of nanomaterials in lung cancer through bibliometric analysis.

MATERIALS AND METHODS

We employed a systematic approach by retrieving studies from the Scopus database that focused on nanomaterials and lung cancer between 2003 and 2023. Subsequently, we carefully selected relevant articles based on predetermined inclusion criteria. The selected publications were then subjected to bibliometric and visual analysis using softwares such as VOSviewer and Biblioshiny.

RESULTS

A total of 3523 studies that meet inclusion criteria were selected for bibliometric analysis. We observed a progressive increase in the number of annual publications from 2003 to 2023, indicating the growing interest in this field. According to our analysis, China is the primary contributor to publication output among the countries. The "Ministry of Education of the People's Republic of China" was the most influential institution. Among the authors, "Dr. Jack A. Roth" and "Dr. Huang Leaf" had the highest number of publications and cited publications, respectively. The "International Journal of Nanomedicine" was found to be the most prolific journal in this field. Additionally, "Biomaterials" emerged as the most cited journal. Through keyword analysis, we identified five main research themes and future research directions; nono-immunotherapy and green synthesis are the hot topics in this research field.

CONCLUSION

Our study summarized the key characteristics of publications in this field and identified the most influential countries, institutions, authors, journals, hot topics, and trends related to the application of nanomaterials in lung cancer. These findings contribute to the existing body of knowledge and serve as a foundation for future research endeavors in this area. More effective efforts are needed in this field to reduce the burden of lung cancer and help achieve the United Nation's Sustainable Development Goals.

Enhanced Therapeutic Efficacy of Gold Nanoparticle-Enhanced Laser Therapy for Oral Cancer: A Promising Photothermal Approach

Introduction: Laser therapy employs a concentrated and slender light beam to eliminate or eradicate cancerous cells and pre-cancerous abnormalities. The specific wavelength of 808 nm light is preferentially absorbed by tumor cells compared to healthy cells. This study aimed to assess the combined therapeutic impact of laser and gold, given that gold exhibits photothermal properties when exposed to laser radiation. Methods: In this in vitro study, two cell lines, namely healthy HuGu cells (human gingival fibroblast cells) and head and neck cancer cells (HN-5), were obtained from the Pasteur Institute. The effect of the laser diode with a density of 3 J/cm2 and wavelength of 808 nm on the proliferation and the survival rate of oral squamous cell carcinoma (HN-5) and human gingival fibroblast (HUGU) was assessed in 60seconds. MTT assay, DAPI test, and trypan blue staining were used to determine the growth and proliferation of HN-5 and HUGU cell lines. Results: Findings showed that the laser diode along with gold decreased the rate of proliferation and survival cells in HN-5 compared to healthy cells. The changes in the cell population treated with gold and laser diode 808 were insignificant. Conclusion: Findings reveal that using a low-power laser can effectively inhibit the growth of oral cancer cells. It seems that photothermal therapy is a novel approach to oral cancer therapy.

Targeted Chemo-Phototherapy in Red Light with Novel Doxorubicin and Iron(III) Complex-Functionalized Gold Nanoconjugate (Dox-Fe@FA-AuNPs)

The anticancer efficacy of doxorubicin, an anthracycline-based and FDA-approved chemotherapeutic drug, is significantly hindered by acquired chemoresistance and severe side effects despite its potent anticancer properties. To overcome these challenges, we developed an innovative therapeutic formulation that integrates targeted chemotherapy and phototherapy within a single platform using gold nanoparticles (AuNPs). This novel nanoconjugate, designated as Dox-Fe@FA-AuNPs, is co-functionalized with folic acid, doxorubicin, and an iron(III)-phenolate/carboxylate complex, enabling cancer-specific drug activation. Here, we report the synthesis, characterization, and comprehensive physico-chemical and biological evaluations of Dox-Fe@FA-AuNPs. The nanoconjugate exhibited excellent solubility, stability, and enhanced cellular uptake in folate receptor-positive cancer cells. The nanoconjugate was potently cytotoxic against HeLa and MDA-MB-231 cancer cells (HeLa: 105.5±16.52 μg mL-1; MDA-MB-231: 112.0±12.31 μg mL-1; MDA-MB-231 (3D): 156.31±19.35 μg mL-1) while less cytotoxic to the folate(-) cancer cells (MCF-7, A549 and HepG2). The cytotoxicity was attributed to the pH-dependent release of doxorubicin, which preferentially occurs in the acidic tumor microenvironment. Additionally, under red light irradiation, the nanoconjugate generated ROS, inducing caspase-3/7-dependent apoptosis with a photo-index (PI) >50, and inhibited cancer cell migration. Our findings underscore the potential of Dox-Fe@FA-AuNPs as a highly effective and sustainable platform for targeted chemo-phototherapy.

Heating Induced Nanoparticle Migration and Enhanced Delivery in Tumor Treatment Using Nanotechnology

Nanoparticles have been developed as imaging contrast agents, heat absorbers to confine energy into targeted tumors, and drug carriers in advanced cancer treatment. It is crucial to achieve a minimal concentration of drug-carrying nanostructures or to induce an optimized nanoparticle distribution in tumors. This review is focused on understanding how local or whole-body heating alters transport properties in tumors, therefore leading to enhanced nanoparticle delivery or optimized nanoparticle distributions in tumors. First, an overview of cancer treatment and the development of nanotechnology in cancer therapy is introduced. Second, the importance of particle distribution in one of the hyperthermia approaches using nanoparticles in damaging tumors is discussed. How intensive heating during nanoparticle hyperthermia alters interstitial space structure to induce nanoparticle migration in tumors is evaluated. The next section reviews major obstacles in the systemic delivery of therapeutic agents to targeted tumors due to unique features of tumor microenvironments. Experimental observations on how mild local or whole-body heating boosts systemic nanoparticle delivery to tumors are presented, and possible physiological mechanisms are explored. The end of this review provides the current challenges facing clinicians and researchers in designing effective and safe heating strategies to maximize the delivery of therapeutic agents to tumors.

Nanoscale gold nanoparticle (GNP)-laden tumor cell model and its use for estimation of intracellular dose from GNP-induced secondary electrons

BACKGROUND

Gold nanoparticles (GNPs) accumulated within tumor cells have been shown to sensitize tumors to radiotherapy. From a physics point of view, the observed GNP-mediated radiosensitization is due to various downstream effects of the secondary electron (SE) production from internalized GNPs such as GNP-mediated dose enhancement. Over the years, numerous computational investigations on GNP-mediated dose enhancement/radiosensitization have been conducted. However, such investigations have relied mostly on simple cellular geometry models and/or artificial GNP distributions. Thus, it is at least desirable, if not necessary, to conduct further investigations using cellular geometry models that properly reflect realistic cell morphology as well as internalized GNP distributions at the nanoscale.

PURPOSE

The primary aim of this study was to develop a nanometer-resolution geometry model of a GNP-laden tumor cell for computational investigations of GNP-mediated dose enhancement/radiosensitization. The secondary aim was to demonstrate the utility of this model by quantifying GNP-induced SE tracks/dose distribution at sub-cellular levels for further validation of a nanoscopic dose point kernel (nDPK) method against full-fledged Geant4 Monte Carlo (MC) simulation.

METHODS

A transmission electron microscopy (TEM) image of a single cell showing cytoplasm, cellular nucleus, and internalized GNPs in the cellular endosome was segmented into sub-cellular levels based on pixel value thresholding. A corresponding material density was allocated to each pixel, and, by adding a thickness, each pixel was transformed to a geometric voxel and imported as a Geant4-acceptable input geometry file. In Geant4-Penelope MC simulation, a clinical 6 MV photon beam was applied, vertically or horizontally to the cell surface, and energy deposition to the cellular nucleus and cytoplasm, due to SEs emitted by internalized GNPs, was scored. Next, nDPK calculations were performed by generating virtual electron tracks from each GNP voxel to all nucleus and cytoplasm voxels. Subsequently, another set of Geant4 simulation was performed with both Penelope and DNA physics models under the geometry closely mimicking in vitro cell irradiation with a clinical 6 MV photon beam, allowing for derivation of nDPK specific to this geometry and further comparison between Gean4 simulation and nDPK method.

RESULTS

The Geant4-calculated SE tracks and associated energy depositions showed significant dependence on photon incidence angle. For perpendicular incidence, nDPK results showed good agreement (average percentage pixel-to-pixel difference of 0.4% for cytoplasm and 0.5% for nucleus) with Geant4 results, while, for parallel incidence, the agreement became worse (-1.7%-0.7% for cytoplasm and -5.5%-0.8% for nucleus). Under the 6 MV cell irradiation geometry, nDPK results showed reasonable agreement (pixel-to-pixel Pearson's product moment correlation coefficient of 0.91 for cytoplasm and 0.98 for nucleus) with Geant4 results.

CONCLUSIONS

The currently developed TEM-based model of a GNP-laden cell offers unprecedented details of realistic intracellular GNP distributions for nanoscopic computational investigations of GNP-mediated dose enhancement/radiosensitization. A benchmarking study performed with this model showed reasonable agreement between Geant4- and nDPK-calculated intracellular dose deposition by SEs emitted from internalized GNPs, especially under perpendicular incidence - a popular cell irradiation geometry and when the Geant4-Penelope physics model was used.

Hard X-ray inverse Compton scattering at photon energy of 87.5 keV

Production of hard X-ray via inverse Compton scattering at photon energies below 100 keV range aimed at potential applications in medicine and material research is reported. Experiments have been performed at the Brookhaven National Laboratory, Accelerator Test Facility, employing the counter collision of a 70 MeV, 0.3 nC electron beam with a near infra-red Nd: YAG laser (1064 nm wavelength) pulse containing ~ 100 mJ in a single shot basis. The radiation distribution of the scattered photon beam is assessed to be sufficiently quasi monochromatic to produce clear contrast from the Au K- edge at 80.7 keV.

Nanoparticle-mediated metronomic chemotherapy in cancer: A paradigm of precision and persistence

Current methods of cancer therapy have demonstrated enormous potential in tumor inhibition. However, a high dosage regimen of chemotherapy results in various complications which affect the normal body cells. Tumor cells also develop resistance against the prescribed drugs in the whole treatment regimen increasing the risk of cancer relapse. Metronomic chemotherapy is a modern treatment method that involves administering drugs at low doses continuously, allowing the drug sufficient time to take its effect. This method ensures that the toxicity of the drugs is to a minimum in comparison to conventional chemotherapy. Nanoparticles have shown efficacy in delivering drugs to the tumor cells in various cancer therapies. Combining nanoparticles with metronomic chemotherapy can yield better treatment results. This combination stimulates the immune system, improving cancer cells recognition by immune cells. Evidence from clinical and pre-clinical trials supports the use of metronomic delivery for drug-loaded nanoparticles. This review focuses on the functionalization of nanoparticles for improved drug delivery and inhibition of tumor growth. It emphasizes the mechanisms of metronomic chemotherapy and its conjunction with nanotechnology. Additionally, it explores tumor progression and the current methods of chemotherapy. The challenges associated with nano-based metronomic chemotherapy are outlined, paving the way for prospects in this dynamic field.

Innovative methodology for noninvasive spatial mapping of gold nanoparticle distribution in tissues: potential applications in biomedical imaging and therapy

Gold nanoparticles (AuNPs) have emerged as versatile agents in biomedical applications, particularly for enhancing contrast in tagged biological tissues for tumor imaging and diagnostics due to their strong absorption cross-section. In this study, we present a methodology for quantifying the spatial distribution of AuNPs within superficial tissue volumes. Utilizing silicone tissue phantoms as a background medium and spatial frequency domain imaging (SFDI) to measure the tissues' optical properties, we constructed a lookup table (LUT) to infer the optical properties of embedded AuNPs with varying spatial concentrations and depths across multiple spatial frequencies. An analytical solution derived from the LUT facilitated the determination of embedded NP concentration in-depth as a function of measured spatial frequency-dependent optical absorption. Notably, SFDI enabled the spatial localization of NPs in three dimensions. These findings lay the foundation for future in vivo studies on mapping NPs and hold significant promise for advancing biomedical imaging techniques.

Efficient production of uniform gold nanoparticles via a streamlined low-cost, semi-automated, open-source platform

In the quest to discover dependable and repeatable methods for producing noble metal nanospheres, both commercial and academic scientists have shown great interest. The challenge of precisely controlling the size of these nanospheres is critical, as variations can alter their optical characteristics, leading to complications in subsequent applications. In this context, we present the design and validation of an affordable, semi-automated device that synthesizes gold nanoparticles using the Turkevich method. This device, named 'NanoSynth Mini' and powered by Raspberry Pi, demonstrates the capability to generate gold nanoparticles with diameters ranging from 15 to 60 nanometers with minimal variability. Its design allows for seamless integration into lab processes, providing consistent support for extensive research initiatives.

Long-Term Accumulation, Biological Effects and Toxicity of BSA-Coated Gold Nanoparticles in the Mouse Liver, Spleen, and Kidneys

Introduction

Gold nanoparticles are promising candidates as vehicles for drug delivery systems and could be developed into effective anticancer treatments. However, concerns about their safety need to be identified, addressed, and satisfactorily answered. Although gold nanoparticles are considered biocompatible and nontoxic, most of the toxicology evidence originates from in vitro studies, which may not reflect the responses in complex living organisms.

Methods

We used an animal model to study the long-term effects of 20 nm spherical AuNPs coated with bovine serum albumin. Mice received a 1 mg/kg single intravenous dose of nanoparticles, and the biodistribution and accumulation, as well as the organ changes caused by the nanoparticles, were characterized in the liver, spleen, and kidneys during 120 days.

Results

The amount of nanoparticles in the organs remained high at 120 days compared with day 1, showing a 39% reduction in the liver, a 53% increase in the spleen, and a 150% increase in the kidneys. The biological effects of chronic nanoparticle exposure were associated with early inflammatory and fibrotic responses in the organs and were more pronounced in the kidneys, despite a negligible amount of nanoparticles found in renal tissues.

Conclusion

Our data suggest, that although AuNPs belong to the safest nanomaterial platforms nowadays, due to their slow tissue elimination leading to long-term accumulation in the biological systems, they may induce toxic responses in the vital organs, and so understanding of their long-term biological impact is important to consider their potential therapeutic applications.

Emerging molecules, tools, technology, and future of surgical knife in gastroenterology

The 21st century has started with several innovations in the medical sciences, with wide applications in health care management. This development has taken in the field of medicines (newer drugs/molecules), various tools and technology which has completely changed the patient management including abdominal surgery. Surgery for abdominal diseases has moved from maximally invasive to minimally invasive (laparoscopic and robotic) surgery. Some of the newer medicines have its impact on need for surgical intervention. This article focuses on the development of these emerging molecules, tools, and technology and their impact on present surgical form and its future effects on the surgical intervention in gastroenterological diseases.

Sarcoma cell-specific radiation sensitization by titanate scrolled nanosheets: insights from physicochemical analysis and transcriptomic profiling

This study aimed to explore the potential of metal oxides such as Titanate Scrolled Nanosheets (TNs) in improving the radiosensitivity of sarcoma cell lines. Enhancing the response of cancer cells to radiation therapy is crucial, and one promising approach involves utilizing metal oxide nanoparticles. We focused on the impact of exposing two human sarcoma cell lines to both TNs and ionizing radiation (IR). Our research was prompted by previous in vitro toxicity assessments, revealing a correlation between TNs' toxicity and alterations in intracellular calcium homeostasis. A hydrothermal process using titanium dioxide powder in an alkaline solution produced the TNs. Our study quantified the intracellular content of TNs and analyzed their impact on radiation-induced responses. This assessment encompassed PIXE analysis, cell proliferation, and transcriptomic analysis. We observed that sarcoma cells internalized TNs, causing alterations in intracellular calcium homeostasis. We also found that irradiation influence intracellular calcium levels. Transcriptomic analysis revealed marked disparities in the gene expression patterns between the two sarcoma cell lines, suggesting a potential cell-line-dependent nano-sensitization to IR. These results significantly advance our comprehension of the interplay between TNs, IR, and cancer cells, promising potential enhancement of radiation therapy efficiency.

Applications of nanomaterials in anti-VEGF treatment for ophthalmic diseases

Angiogenesis has been determined to be essential in the occurrence and metastasis of diabetic retinopathy (DR), age-related macular degeneration (AMD), retinal vein occlusion (RVO), choroidal neovascularization (CNV), retinopathy of prematurity (ROP), tumor, etc. However, the clinical use of anti-vascular endothelial growth factors (VEGF) drugs is currently limited due to its high cost, potential side effects, and need for repeated injections. In recent years, nanotechnology has shown promising results in inhibiting neovascularization and reducing reactive oxygen species (ROS) or inflammatory factors. Some nanomaterials can also act as vehicles for drug delivery, such as lipid nanoparticles and PLGA. The process of angiogenesis and its molecular mechanism are discussed in this article. At the same time, this study aims to systematically review the research progress of nanotechnology and offer more treatment options for neovascularization-related diseases in clinical ophthalmology.

Harnessing the power of gold: advancements in anticancer gold complexes and their functionalized nanoparticles

Cancer poses a formidable challenge, necessitating improved treatment strategies. Metal-based drugs and nanotechnology offer new hope in this battle. Versatile gold complexes and functionalized gold nanoparticles exhibit unique properties like biologically inert behaviour, outstanding light absorption, and heat-conversion abilities. These nanoparticles can be finely tuned for drug delivery, enabling precise and targeted cancer therapy. Their exceptional drug-loading capacity and low toxicity, stemming from excellent stability, biocompatibility, and customizable shapes, make them a promising option for enhancing cancer treatment outcomes and improving diagnostic imaging. Leveraging these attributes, researchers can design more effective and targeted cancer therapeutics. The potential of functionalized gold nanoparticles to advance cancer treatment and diagnostics holds a promising avenue for further exploration and development in the fight against cancer. This review article delves into the finely tuned attributes of functionalized gold nanoparticles, unveiling their potential for application in drug delivery for precise and targeted cancer therapy.

Metallic Nanocarriers for Therapeutic Peptides: Emerging Solutions Addressing the Delivery Challenges in Brain Ailments

Peptides and proteins have recently emerged as efficient therapeutic alternatives to conventional therapies. Although they emerged a few decades back, extensive exploration of various ailments or disorders began recently. The drawbacks of current chemotherapies and irradiation treatments, such as drug resistance and damage to healthy tissues, have enabled the rise of peptides in the quest for better prospects. The chemical tunability and smaller size make them easy to design selectively for target tissues. Other remarkable properties include antifungal, antiviral, anti-inflammatory, protection from hemorrhage stroke, and as therapeutic agents for gastric disorders and Alzheimer and Parkinson diseases. Despite these unmatched properties, their practical applicability is often hindered due to their weak susceptibility to enzymatic digestion, serum degradation, liver metabolism, kidney clearance, and immunogenic reactions. Several methods are adapted to increase the half-life of peptides, such as chemical modifications, fusing with Fc fragment, change in amino acid composition, and carrier-based delivery. Among these, nanocarrier-mediated encapsulation not only increases the half-life of the peptides in vivo but also aids in the targeted delivery. Despite its structural complexity, they also efficiently deliver therapeutic molecules across the blood-brain barrier. Here, in this review, we tried to emphasize the possible potentiality of metallic nanoparticles to be used as an efficient peptide delivery system against brain tumors and neurodegenerative disorders. SIGNIFICANCE STATEMENT: In this review, we have emphasized the various therapeutic applications of peptides/proteins, including antimicrobial, anticancer, anti-inflammatory, and neurodegenerative diseases. We also focused on these peptides' challenges under physiological conditions after administration. We highlighted the importance and potentiality of metallic nanocarriers in the ability to cross the blood-brain barrier, increasing the stability and half-life of peptides, their efficiency in targeting the delivery, and their diagnostic applications.

Effect of detector placement on joint estimation in X-ray fluorescence emission tomography

Imaging the spatial distribution of low concentrations of metal is a growing problem of interest with applications in medical and material sciences. X-ray fluorescence emission tomography (XFET) is an emerging metal mapping imaging modality with potential sensitivity improvements and practical advantages over other methods. However, XFET detector placement must first be optimized to ensure accurate metal density quantification and adequate spatial resolution. In this work, we first use singular value decomposition of the imaging model and eigendecomposition of the object-specific Fisher information matrix to study how detector arrangement affects spatial resolution and feature preservation. We then perform joint image reconstructions of a numerical gold phantom. For this phantom, we show that two parallel detectors provide metal quantification with similar accuracy to four detectors, despite the resulting anisotropic spatial resolution in the attenuation map estimate. Two orthogonal detectors provide improved spatial resolution along one axis, but underestimate the metal concentration in distant regions. Therefore, this work demonstrates the minor effect of using fewer, but strategically placed, detectors in the case where detector placement is restricted. This work is a critical investigation into the limitations and capabilities of XFET prior to its translation to preclinical and benchtop uses.

Properties and potential applications of bioconjugates of R-phycoerythrin with Ag° or CdS nanoparticle synthesized in its tunnel cavity: A review

Green synthesis is a promising method for the preparation of nanoparticles (NPs) due to its simplicity, low cost, low toxicity, and environmental friendliness. Biosynthesized NPs exhibit multifunctional activity, good biocompatibility, and higher anticancer and antibacterial activity compared to chemically synthesized NPs. R-phycoerythrin, a photosynthetic light-harvesting pigment of protein nature (M.w. 290 kDa), is an attractive platform for the synthesis of small sizes NPs due to its structural features, non-toxicity, water solubility. Photosensitive bioconjugates of R-phycoerythrin with NPs were prepared by synthesizing Ag° and CdS NPs in tunnel cavities of R-phycoerythrin (3.5 × 6.0 nm) isolated from the red seaweed Callithamnion rubosum. The review is devoted to the physical processes and chemical reactions that occur in the native protein macromolecule of a complex structure during the synthesis of a NP in its cavity. The influence of Ago and CdS NPs on the electronic processes caused by the absorption of photons, leading to reversible and irreversible changes in R-phycoerythrin has been analyzed. Properties of R-phycoerythrin bioconjugates Ag° and CdS with NPs combined with the literature data suggest potential applications of Ag°⋅PE and CdS⋅PE bioconjugates for cancer diagnosis, treatment, and monitoring as well as for realizing theranostic strategy in the future. The use of these bioconjugates in anticancer therapy may have synergistic effects since both R-phycoerythrin and NPs induce cancer cell death.

The Potential of Nanotechnology to Replace Cancer Stem Cells

Stem cells, which were initially identified in the 1900s, are distinct cells with the potential to replenish themselves as well as differentiate into specialised cells with certain forms and functions. Cancer stem cells play a significant role in the growth and recurrence of the tumours and, similar to normal stem cells, are capable of proliferating and differentiating. Traditional cancer treatments are ineffective against cancer stem cells, which leads to tumour regrowth. Cancer stem cells are thought to emerge as a result of epithelial-to-mesenchymal transition pathways. Brain, prostate, pancreatic, blood, ovarian, lung, liver, melanomas, AML, and breast cancer stem cells are among the most prevalent cancer forms. This review aims to comprehend the possibility of using specific forms of nanotechnology to replace cancer stem cells. In terms of nanotechnology, magnetic nanoparticles can deliver medications, especially to the target region without harming healthy cells, and they are biocompatible. In order to kill glioma cancer stem cells, the gold nanoparticles bond with DNA and function as radio sensitizers. In contrast, liposomes can circulate and traverse biological membranes and exhibit high therapeutic efficacy, precise targeting, and better drug release. Similar to carbon nanotubes, grapheme, and grapheme oxide, these substances can be delivered specifically when utilized in photothermal therapy. Recent treatments including signaling pathways and indicators targeted by nanoparticles are being researched. Future research in nanotechnology aims to develop more effective and targeted medicinal approaches. The results of the current investigation also showed that this technology's utilization will improve medical therapy and treatment.

Progress in Programmable DNA-Aided Self-Assembly of the Master Frame of a Drug Delivery System

Every year cancer causes approximately 10 million deaths globally. Researchers have developed numerous targeted drug delivery systems (DDSs) with nanoparticles, polymers, and liposomes, but these synthetic materials have poor degradability and low biocompatibility. Because DNA nanostructures have good degradability and high biocompatibility, extensive studies have been performed to construct DDSs with DNA nanostructures as the molecular-layer master frame (MF) assembled via programmable DNA-aided self-assembly for targeted drug release. To learn the progressing trend of self-assembly techniques and keep pace with their recent rapid advancements, it is crucial to provide an overview of their past and recent progress. In this review article, we first present the techniques to assemble the MF of a DDS with solely DNA strands; to assemble MFs with one or more additional type of construction materials, e.g., polymers (including RNA and protein), inorganic nanoparticle, or metal ions, in addition to DNA strands; and to assemble the more complex DNA nanocomplexes. It is observed that both the techniques used and the MFs constructed have become increasingly complex and that the DDS constructed has an increasing number of advanced functions. From our focused review, we anticipate that DDSs with the MF of multiple building materials and DNA nanocomplexes will attract an increasing number of researchers' interests. On the basis of knowledge about materials and functional components (e.g., targeting aptamers/peptides/antibodies and stimuli for drug release) obtained from previously performed studies, researchers can combine more materials with DNA strands to assemble more powerful MFs and incorporate more components to endow DDSs with improved or additional properties/functions, thereby subsequently contributing to cancer prevention.

Flavonoids Regulate Redox-Responsive Transcription Factors in Glioblastoma and Microglia

The tumor microenvironment (TME) has emerged as a valuable therapeutic target in glioblastoma (GBM), as it promotes tumorigenesis via an increased production of reactive oxygen species (ROS). Immune cells such as microglia accumulate near the tumor and its hypoxic core, fostering tumor proliferation and angiogenesis. In this study, we explored the therapeutic potential of natural polyphenols with antioxidant and anti-inflammatory properties. Notably, flavonoids, including fisetin and quercetin, can protect non-cancerous cells while eliminating transformed cells (2D cultures and 3D tumoroids). We tested the hypothesis that fisetin and quercetin are modulators of redox-responsive transcription factors, for which subcellular location plays a critical role. To investigate the sites of interaction between natural compounds and stress-responsive transcription factors, we combined molecular docking with experimental methods employing proximity ligation assays. Our findings reveal that fisetin decreased cytosolic acetylated high mobility group box 1 (acHMGB1) and increased transcription factor EB (TFEB) abundance in microglia but not in GBM. Moreover, our results suggest that the most powerful modulator of the Nrf2-KEAP1 complex is fisetin. This finding is in line with molecular modeling and calculated binding properties between fisetin and Nrf2-KEAP1, which indicated more sites of interactions and stronger binding affinities than quercetin.

Aptamer-modified chitosan-capped mesoporous silica nanoparticles for co-delivery of cytarabine and daunorubicin in leukemia

In this study, surface modified mesoporous silica nanoparticles (MSNs) were prepared for the targeted delivery of the anticancer agents, daunorubicin (DNR) and cytarabine (CTR), against K562 leukemia cancer cell lines. The MSNs were surface-modified with pH-sensitive chitosan (CS) to prevent the burst release of anticancer agents at the physiological pH of 7.4 and to enable a higher drug release at lower pH and higher concentration of glutathione. Finally, the MSNs were surface modified with KK1B10 aptamer (Apt) to enhance their uptake by K562 cells through ligand-receptor interactions. The MSNs were characterized using different methods and both in vitro and in vivo experiments were utilized to demonstrate their suitability as targeted anticancer agents. The resultant MSNs exhibited an average particle size of 295 nm, a surface area of 39.06 m2/g, and a cumulative pore volume of 0.09 cm3/g. Surface modification of MSNs with chitosan (CS) resulted in a more regulated and acceptable continuous release rate of DNR. The drug release rate was significantly higher at pH 5 media enriched with glutathione, compared to pH 7.4. Furthermore, MSNs coated with CS and conjugated with aptamer (MSN-DNR + CTR@CS-Apt) exhibited a lower IC50 value of 2.34 µg/ml, compared to MSNs without aptamer conjugation, which displayed an IC50 value of 12.27 µg/ml. The results of the cell cycle analysis indicated that the administration of MSN-DNR + CTR@CS-Apt led to a significant increase in the population of apoptotic cells in the sub-G1 phase. Additionally, the treatment arrested the remaining cells in various other phases of the cell cycle. Furthermore, the interactions between Apt-receptors were found to enhance the uptake of MSNs by cancer cells. The results of in vivo studies demonstrated that the administration of MSN-DNR + CTR@CS-Apt led to a significant reduction in the expression levels of CD71 and CD235a markers, as compared to MSN-DNR + CTR@CS (p < 0.001). In conclusion, the surface modified MSNs prepared in this study showed lower IC50 against cancer cell lines and higher anticancer activity in animal models.

Application of nanomaterials as potential quorum quenchers for disease: Recent advances and challenges

Chemical signal molecules are used by bacteria to interact with one another. Small hormone-like molecules known as autoinducers are produced, released, detected, and responded to during chemical communication. Quorum Sensing (QS) is the word for this procedure; it allows bacterial populations to communicate and coordinate group behavior. Several research has been conducted on using inhibitors to prevent QS and minimize the detrimental consequences. Through the enzymatic breakdown of the autoinducer component, by preventing the formation of autoinducers, or by blocking their reception by adding some compounds (inhibitors) that can mimic the autoinducers, a technique known as "quorum quenching" (QQ) disrupts microbial communication. Numerous techniques, including colorimetry, electrochemistry, bioluminescence, chemiluminescence, fluorescence, chromatography-mass spectroscopy, and many more, can be used to test QS/QQ. They all permit quantitative and qualitative measurements of QS/QQ molecules. The mechanism of QS and QQ, as well as the use of QQ in the prevention of biofilms, are all elaborated upon in this writing, along with the fundamental study of nanoparticle (NP)in QQ. Q.

Recent developments in photodynamic therapy and its application against multidrug resistant cancers

Recently, photodynamic therapy (PDT) has received a lot of attention for its potential use in cancer treatment. It enables the therapy of a multifocal disease with the least amount of tissue damage. The most widely used prodrug is 5-aminolevulinic acid, which undergoes heme pathway conversion to protoporphyrin IX, which acts as a photosensitizer (PS). Additionally, hematoporphyrin, bacteriochlorin, and phthalocyanine are also studied for their therapeutic potential in cancer. Unfortunately, not every patient who receives PDT experiences a full recovery. Resistance to different anticancer treatments is commonly observed. A few of the resistance mechanisms by which cancer cells escape therapeutics are genetic factors, drug-drug interactions, impaired DNA repair pathways, mutations related to inhibition of apoptosis, epigenetic pathways, etc. Recently, much research has been conducted to develop a new generation of PS based on nanomaterials that could be used to overcome cancer cells' multidrug resistance (MDR). Various metal-based, polymeric, lipidic nanoparticles (NPs), dendrimers, etc, have been utilized in the PDT application against cancer. This article discusses the detailed mechanism by which cancer cells evolve towards MDR as well as recent advances in PDT-based NPs for use against multidrug-resistant cancers.

Dog-bone shaped gold nanoparticle-mediated chemo-photothermal therapy impairs the powerhouse to trigger apoptosis in cancer cells

The mitochondrion has emerged as one of the uncommon targets in cancer therapeutics due to its involvement in cancer generation and progression. Consequently, nanoplatform mediated delivery of anti-cancer drugs into the mitochondria of cancer tissues demonstrated immense potential in cancer treatment. In the last couple of decades, gold nanoparticles have gained incredible attention in biomedical applications due to their easy synthesis, size-shape tenability, optical properties and outstanding photothermal ability. However, application of gold nanoparticles to target mitochondria to induce the chemo-photothermal effect in cancer has remained in its infancy. To address this, herein we have engineered dog-bone shaped gold nanoparticles (Mito-AuDB-NPs) comprising cisplatin and 10-hydroxycamptothecin as chemotherapeutic drugs along with the triphenylphosphonium (TPP) cation for mitochondria homing. Mito-AuDB-NPs exhibited a remarkable increase in temperature till 56 °C upon 18 min irradiation with 740 nm NIR LED light with a power density of 0.9 W cm-2. These Mito-AuDB-NPs successfully homed into the mitochondria of HeLa cervical cancer cells within 1 h and induced mitochondrial outer membrane permeabilization (MOMP) under the chemo-photothermal effect leading to the generation of reactive oxygen species (ROS). This Mito-AuDB-NP-mediated mitochondrial damage triggered programmed cell death (apoptosis) by decreasing the expression of anti-apoptotic Bcl-2/Bcl-xl and increasing the expression of pro-apoptotic BAX followed by caspase-3 cleavage towards extraordinary HeLa cell killing in a synergistic manner without showing toxicity towards non-cancerous RPE-1 human epithelial retinal pigment cells. We anticipate that this dog-bone shaped gold nanoparticle-mediated chemo-photothermal impairment of mitochondria in the cancer cells can open a new direction towards organelle targeted cancer therapy.

Impact of Surface Charge-Tailored Gold Nanorods for Selective Targeting of Mitochondria in Breast Cancer Cells Using Photodynamic Therapy

Herein, the impact of surface charge tailored of gold nanorods (GNRs) on breast cancer cells (MCF-7 and MDA-MB-231) upon conjugation with triphenylphosphonium (TPP) for improved photodynamic therapy (PDT) targeting mitochondria was studied. The salient features of the study are as follows: (i) positive (CTAB@GNRs) and negative (PSS-CTAB@GNRs) surface-charged gold nanorods were developed and characterized; (ii) the mitochondrial targeting efficiency of gold nanorods was improved by conjugating TPP molecules; (iii) the conjugated nanoprobes (TPP-CTAB@GNRs and TPP-PSS-CTAB@GNRs) were evaluated for PDT in the presence of photosensitizer (PS), 5-aminolevulinic acid (5-ALA) in breast cancer cells; (iv) both nanoprobes (TPP-CTAB@GNRs and TPP-PSS-CTAB@GNRs) induce apoptosis, damage DNA, generate reactive oxygen species, and decrease mitochondrial membrane potential upon 5-ALA-based PDT; and (v) 5-ALA-PDT of two nanoprobes (TPP-CTAB@GNRs and TPP-PSS-CTAB@GNRs) impact cell signaling (PI3K/AKT) pathway by upregulating proapoptotic genes and proteins. Based on the results, we confirm that the positively charged (rapid) nanoprobes are more advantageous than their negatively (slow) charged nanoprobes. However, depending on the kind and degree of cancer, both nanoprobes can serve as efficient agents for delivering anticancer therapy.

Honey gold nanoparticles attenuate the secretion of IL-6 by LPS-activated macrophages

Interleukin-6 (IL-6) is a pleiotropic cytokine that coordinates host immune responses to infection. Though essential to the acute phase response, prolonged IL-6-mediated recruitment of mononuclear cells has been implicated in chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, and Crohn's disease. Accordingly, identifying novel therapeutics that diminish circulating IL-6 levels could benefit individuals suffering from chronic inflammation. In immunocompetent hosts, bacterial lipopolysaccharide (LPS) recognition by toll-like receptor 4 (TLR4) activates the transcription factor NF-κB, driving macrophage production of IL-6. Interestingly, both citrate-stabilized and 'green' synthesized gold nanoparticles (AuNPs) have been shown to modulate the cytokine responses of LPS-activated macrophages. Here we demonstrate that AuNPs, synthesized with commercial and locally sourced honey, downregulate LPS-induced macrophage secretion of IL-6. Compared to LPS-only controls, inhibition of IL-6 levels was observed for all three types of honey AuNPs. The effect was likely driven by honey AuNP-mediated perturbation of the TLR4/NF-κB signaling pathway, as evidenced by a reduction in the phosphorylation of IκB. Further investigation into the anti-inflammatory properties of honey AuNPs may yield novel therapeutics for the treatment of chronic inflammation.

Engineering of functional nanosnowflakes from gold nanocarriers capped with amino-modified DNA oligonucleotides

The design, engineering and electron microscopic characterization of anisotropic nanosized snowflake-like structural assemblies (nanosnowflakes) is reported. They were fabricated through immobilization of double stranded amine-modified and thiol-terminated DNA oligonucleotides on the surface of ultra-small isotropic gold nanoparticles used as nanocarriers. The transmission electron microscopy images combined with spectrophotometric data revealed the formation of self-assembled structural aggregation between individual ligands-coated nanoparticles. They act as seeds for the further spontaneous dendritic growth in different directions. Their anisotropic morphology is formed due to the occurrence of facilitated electrostatic interactions between positive charged amino-groups and the negative sugar-phosphate backbone of oligonucleotides. Thus, nanosnowflakes with size distribution between 40 and 80 nm were obtained. The microscopic analysis demonstrated also that the stable nanosnowflakes structure was highly dependent on the solution ionic strength, which effect the charge fluctuation within the assembly. The reported DNA functionalized nanostructures have potential to be applied as a platform for development of therapeutic materials, as well as drug delivery nanosystems. RESEARCH HIGHLIGHTS: The engineering, fabrication, and microscopic characterization of DNA nanosnowflakes is reported. The electron microscopy analysis revealed formation of self-assemblies with anisotropic morphology. The nanosnowflakes size distribution was between 40 and 80 nm.

Challenges and Opportunities Associated With Drug Delivery for the Treatment of Solid Tumors

In this review, we discuss the effectiveness of drug delivery system based on metal nanoparticles, and also, describe the problems associated with their delivery to tumor cells. Throughout recent years, more reports have appeared in the literature that demonstrate promising results for the treatment of various types of cancer using metal-based nanoparticles. Due to their unique physical and chemical properties, metal nanoparticles are effectively being used for the delivery of drug to the tumor cells, for cancer diagnosis and treatment. They can also be synthesized allowing the control of size and shape. However, the effectiveness of the metal nanoparticles for cancer treatment largely depends on their stability, biocompatibility, and ability to selectively affect tumor cells after their systemic or local administration. Another major problem associated with metal nanoparticles is their ability to overcome tumor tissue barriers such as atypical blood vessel structure, dense and rigid extracellular matrix, and high pressure of tumor interstitial fluid. The review also describes the design of tumor drug delivery systems that are based on metal nanoparticles. The mechanism of action of metal nanoparticles on cancer cells is also discussed. Considering the therapeutic safety and toxicity of metal nanoparticles, the prospects for their use for future clinical applications are being currently reviewed.

Deep Learning-Based TEM Image Analysis for Fully Automated Detection of Gold Nanoparticles Internalized Within Tumor Cell

Transmission electron microscopy (TEM) imaging can be used for detection/localization of gold nanoparticles (GNPs) within tumor cells. However, quantitative analysis of GNP-containing cellular TEM images typically relies on conventional/thresholding-based methods, which are manual, time-consuming, and prone to human errors. In this study, therefore, deep learning (DL)-based methods were developed for fully automated detection of GNPs from cellular TEM images. Several models of "you only look once (YOLO)" v5 were implemented, with a few adjustments to enhance the model's performance by applying the transfer learning approach, adjusting the size of the input image, and choosing the best optimization algorithm. Seventy-eight original (12,040 augmented) TEM images of GNP-laden tumor cells were used for model implementation and validation. A maximum F1 score (harmonic mean of the precision and recall) of 0.982 was achieved by the best-trained models, while mean average precision was 0.989 and 0.843 at 0.50 and 0.50-0.95 intersection over union threshold, respectively. These results suggested the developed DL-based approach was capable of precisely estimating the number/position of internalized GNPs from cellular TEM images. A novel DL-based TEM image analysis tool from this study will benefit research/development efforts on GNP-based cancer therapeutics, for example, by enabling the modeling of GNP-laden tumor cells using nanometer-resolution TEM images.

Gold nanoparticles synthesis and immobilization by atmospheric pressure DBD plasma torch method

Herein, we report the impact of plasma on gold nanoparticles synthesis. We used an atmospheric plasma torch fed with an aerosolized tetrachloroauric(iii) acid trihydrate (HAuCl₄·3H₂O) solution. The investigation showed that using pure ethanol as a solvent for the gold precursor enabled a better dispersion compared to a water-containing solution. We demonstrated here that the deposition parameters are easy to control, presenting the influence of solvent concentration and deposition time. The advantage of our method is that no capping agent was used. We assume that plasma creates a carbon-based matrix around the gold nanoparticles preventing them to agglomerate. The XPS results revealed the impact of using plasma. Metallic gold was detected in the plasma-treated sample, whereas the no-plasma sample revealed only Au(i) and Au(iii) contributions originating from the HAuCl₄ precursor. Detailed HRTEM, EDS mapping, and SAED analyses led to more insights into the structure.

Nanomaterial-based contrast agents

Medical imaging, which empowers the detection of physiological and pathological processes within living subjects, has a vital role in both preclinical and clinical diagnostics. Contrast agents are often needed to accompany anatomical data with functional information or to provide phenotyping of the disease in question. Many newly emerging contrast agents are based on nanomaterials as their high payloads, unique physicochemical properties, improved sensitivity and multimodality capacity are highly desired for many advanced forms of bioimaging techniques and applications. Here, we review the developments in the field of nanomaterial-based contrast agents. We outline important nanomaterial design considerations and discuss the effect on their physicochemical attributes, contrast properties and biological behaviour. We also describe commonly used approaches for formulating, functionalizing and characterizing these nanomaterials. Key applications are highlighted by categorizing nanomaterials on the basis of their X-ray, magnetic, nuclear, optical and/or photoacoustic contrast properties. Finally, we offer our perspectives on current challenges and emerging research topics as well as expectations for future advancements in the field.

Pegylated Gold Nanoparticles Conjugated with siRNA: Complexes Formation and Cytotoxicity

Drug delivery systems such as dendrimers, liposomes, polymers or gold/silver nanoparticles could be used to advance modern medicine. One significant pharmacological problem is crossing biological barriers by commonly used drugs, e.g., in the treatment of neurodegenerative diseases, which have a problem of the blood-brain barrier (BBB) restricting drug delivery. Numerous studies have been conducted to find appropriate drug carriers that are safe, biocompatible and efficient. In this work, we evaluate pegylated gold nanoparticles AuNP14a and AuNP14b after their conjugation with therapeutic siRNA directed against APOE4. This genetic risk factor remains the strongest predictor for late-onset Alzheimer’s disease. The study aimed to assess the biophysical properties of AuNPs/siAPOE complexes and to check their biological safety on healthy cells using human brain endothelial cells (HBEC-5i). Techniques such as fluorescence polarization, circular dichroism, dynamic light scattering, ζ-potential measurements and gel retardation assay showed that AuNPs form stable complexes with siRNA. Subsequently, cytotoxicity assays proved the biological safety of formed conjugates. Obtained results enabled us to find effective concentrations of AuNPs when complexes are formed and non-toxic for healthy cells. One of the studied nanoparticles, AuNP14b complexed with siRNA, displayed lower cytotoxicity (MTT assay, cells viability −74.8 ± 3.1%) than free nanoparticles (44.7 ± 3.6%). This may be promising for further investigations in nucleic acid delivery and could have practical use in treating neurodegenerative diseases.

Red light-activable biotinylated copper(II) complex-functionalized gold nanocomposite (Biotin-Cu@AuNP) towards targeted photodynamic therapy

We report the synthesis and characterization of red-light activable gold nanoparticle functionalized with biotinylated copper(II) complex of general molecular formula, [Cu(L³)(L⁶)]-AuNPs (Biotin-Cu@AuNP), where L³ = N-(3-((E)-3,5-di-tert-butyl-2-hydroxybenzylideneamino)-4-hydroxyphenyl)-5-((3aS,4S,6aR)-2-oxo-hexahydro-1H-thieno[3,4-d]imidazol-4-yl)pentanamide, L⁶ = 5-(1,2-dithiolan-3-yl)-N-(1,10-phenanthrolin-5-yl)pentanamide, which was explored for their photophysical, theoretical and photo-cytotoxic potentials. The nanoconjugate exhibits differential uptake in biotin positive and biotin negative cancer cells as well as normal cells. The nanoconjugate also shows remarkable photodynamic activity against biotin positive A549 (IC₅₀: 13 μg/mL in red light; >150 μg/mL in dark) and HaCaT (IC₅₀: 23 μg/mL in red light; >150 μg/mL in dark) cells under red light (600-720 nm, 30 Jcm^-2) irradiation, with significantly high photo-indices (PI>15). The nanoconjugate is less toxic to HEK293T (biotin negative) and HPL1D (normal) cells. Confocal microscopy confirms preferential mitochondrial and partly cytoplasmic localization of Biotin-Cu@AuNP in A549 cells. Several photo-physical and theoretical studies reveal the red light-assisted generation of singlet oxygen (¹O₂) (Ф (¹O₂) =0.68) as a reactive oxygen species (ROS) which results in remarkable oxidative stress and mitochondrial membrane damage, leading to caspase 3/7-dependent apoptosis of A549 cells. Overall, the nanocomposite (Biotin-Cu@AuNP) exhibiting red light-assisted targeted photodynamic activity has emerged as the ideal next generation PDT agents.