Gold Nanoparticles in Diagnostics and Therapeutics for Human Cancer

Current Knowledge of Silver and Gold Nanoparticles in Laboratory Research-Application, Toxicity, Cellular Uptake

Silver and gold nanoparticles can be found in a range of household products related to almost every area of life, including patches, bandages, paints, sportswear, personal care products, food storage equipment, cosmetics, disinfectants, etc. Their confirmed ability to enter the organism through respiratory and digestive systems, skin, and crossing the blood-brain barrier raises questions of their potential effect on cell function. Therefore, this manuscript aimed to summarize recent reports concerning the influence of variables such as size, shape, concentration, type of coating, or incubation time, on effects of gold and silver nanoparticles on cultured cell lines. Due to the increasingly common use of AgNP and AuNP in multiple branches of the industry, further studies on the effects of nanoparticles on different types of cells and the general natural environment are needed to enable their long-term use. However, some environmentally friendly solutions to chemically synthesized nanoparticles are also investigated, such as plant-based synthesis methods.

Green Synthesis of Metallic Nanoparticles Using Some Selected Medicinal Plants from Southern Africa and Their Biological Applications

The application of metallic nanoparticles (MNPs), especially that of silver, gold, cobalt, and zinc as antimicrobial, anticancer, drug delivery, contrast, and bioimaging agents has transformed the field of medicine. Their functions, which are attributed to their physicochemical properties, have gained prominence in various technological fields. Although MNPs can be produced via rigorous physical and chemical techniques, in recent years, a biological approach utilizing natural materials has been developed. With the increasing enthusiasm for safe and efficient nanomaterials, the biological method incorporating microorganisms and plants is preferred over physical and chemical methods of nanoparticle synthesis. Of these bio-entities, plants have received great attention owing to their capability to reduce and stabilize MNPs in a single one-pot protocol. South Africa is home to ~10% of the world's plant species, making it a major contributor to the world's ecological scenery. Despite the documented contribution of South African plants, particularly in herbal medicine, very few of these plants have been explored for the synthesis of the noble MNPs. This paper provides a review of some important South African medicinal plants that have been utilized for the synthesis of MNPs. The enhanced biological properties of the biogenic MNPs attest to their relevance in medicine. In this endeavour, more of the African plant biodiversity must be explored for the synthesis of MNPs and be validated for their potential to be translated into future nanomedicine.

Targeted Nanoparticle Photodynamic Diagnosis and Therapy of Colorectal Cancer

Colorectal cancer (CRC) is an aggressive cancer that remains a challenge to diagnose and treat. Photodynamic diagnosis (PDD) and therapy (PDT) are novel alternative techniques, which can enhance early diagnosis, as well as elicit tumor cell death. This is accomplished through photosensitizer (PS) mediated fluorescence and cytotoxic reactive oxygen species activation upon laser light irradiation excitation at specific low and high range wavelengths, respectively. However, the lack of PS target tumor tissue specificity often hampers these techniques. This study successfully fabricated a bioactive nanoconjugate, ZnPcS4-AuNP-S-PEG5000-NH2-Anti-GCC mAb (BNC), based upon a polyethylene glycol-gold nanoparticle, which was multi-functionalized with a fluorescent PDT metalated zinc phthalocyanine PS, and specific anti-GCC targeting antibodies, to overcome CRC PDD and PDT challenges. The BNC was found to be stable and showed selectively improved subcellular accumulation within targeted CRC for improved PDD and PDT outcomes in comparison to healthy in vitro cultured cells. Additionally, the BNC reported significantly higher late apoptotic PDT-induced CRC cell death rates (34% ***) when compared to PDT PS administration alone (15% *). These results indicated that the improved PDD and PDT outcomes were due to the specific PS accumulation in CRC cells through nanoparticle carriage and bioactive anti-GCC targeting.

Astaxanthin and its gold nanoparticles mitigate cadmium toxicity in rice by inhibiting cadmium translocation and uptake

Cadmium (Cd) is one of the main heavy metal in rice, Cd uptake by cereal crops from soil leads to toxicity in plants and pose serious health risks due to human body's accumulation through the food chain. Astaxanthin, a natural and anti-oxidative oxycarotenoid, is widely distributed in various microorganisms and seafood. In this study, we demonstrated that astaxanthin in the form of gold nanoparticles (Ast-AuNPs) can efficiently alleviate Cd toxicity to a greater extent in hydroponically grown rice plants than single astaxanthin. When supplemented with 100 μg/mL Ast-AuNPs in medium, the Cd level of rice was significantly reduced by 26.2% (in roots) and 85.9% (in leaves), respectively. We also found Ast-AuNPs supplement restores chlorophyll biosynthesis and mitigate Cd-induced oxidative stresses: the contents of superoxide anion (O₂^-), hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) were significantly reduced while the activity of the antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) was significantly elevated. Further study showed that the supplement of Ast-AuNPs inhibited Cd-induced gene expression of the metal transporter genes (OsHMA2, OsHMA3, OsIRT1, OsIRT2, OsNramp1, and OsNramp5) in rice roots. Moreover, Ast-AuNPs regulated the metabolism of free amino acids and increased the level of non-enzymatic antioxidants such as glutathione and ascorbic acid. Therefore, this study demonstrates that Ast-AuNPs could mitigate the Cd toxicity in rice seedlings by suppressing Cd uptake, scavenging of ROS, and enhancing the activity of antioxidants, and also expands the application of functional gold nanoparticles in the alleviation of heavy metal pollution in plants.

Advanced nanomedicine approaches applied for treatment of skin carcinoma

Skin-cancer is the commonest malignancy affecting huge proportion of the population, reaching heights in terms of morbidity. The treatment strategies are presently focusing on surgery, radiation and chemotherapy, which eventually cause destruction to unaffected cells. To overcome this limitation, wide range of nanoscaled materials have been recognized as potential carriers for delivering selective response to cancerous cells and neoplasms. Nanotechnological approach has been tremendously exploited in several areas, owing to their functional nanometric dimensions. The alarming incidence of skin cancer engenders burdensome effects worldwide, which is further awakening innovational medicinal approaches, accompanying target specific drug delivery tools for coveted benefits to provide reduced toxicity and tackle proliferative episodes of skin cancer. The developed nanosystems for anti-cancer agents include liposomes, ethosomes, nanofibers, solid lipid nanoparticles and metallic nanoparticles, which exhibit pronounced outcomes for skin carcinoma. In this review, skin cancer with its sub-types is explained in nutshell, followed by compendium of specific nanotechnological tools presented, in addition to therapeutic applications of drug-loaded nano systems for skin cancer.

Dealing with MDR bacteria and biofilm in the post-antibiotic era: Application of antimicrobial peptides-based nano-formulation

The rapid development of multidrug-resistant (MDR) bacteria due to the improper and overuse of antibiotics and the ineffective performance of antibiotics against the difficult-to-treat biofilm-related infections (BRIs) have urgently called for alternative antimicrobial agents and strategies in combating bacterial infections. Antimicrobial peptides (AMPs), owing to their compelling antimicrobial activity against MDR bacteria and BRIs without causing bacteria resistance, have attracted extensive attention in the research field. With the development of nanomaterial-based drug delivery strategies, AMPs-based nano-formulations have significantly improved the therapeutic effects of AMPs by ameliorating their hydrolytic stability, half-life in vivo, and solubility as well as reducing the cytotoxicity and hemolysis, etc. This review has comprehensively summarized the application AMPs-based nano-formulation in various bacterial infections models, including bloodstream infections (specifically sepsis), pulmonary infections, chronic wound infections, gastrointestinal infections, among others. The design of the nanomaterial-based drug delivery systems and the therapeutic effects of the AMPs-based nano-formulations in literature have been categorized and in details discussed. Overall, this review provides insights into the advantages and disadvantages of the current developed AMPs-based nano-formulations in literature for the treatment of bacterial infections, bringing inspirations and suggestions for their future design in the way towards clinical translation.

Gold nanoparticles meet medical radionuclides

Thanks to their unique optical and physicochemical properties, gold nanoparticles have gained increased interest as radiosensitizing, photothermal therapy and optical imaging agents to enhance the effectiveness of cancer detection and therapy. Furthermore, their ability to carry multiple medically relevant radionuclides broadens their use to nuclear medicine SPECT and PET imaging as well as targeted radionuclide therapy. In this review, we discuss the radiolabeling process of gold nanoparticles and their use in (multimodal) nuclear medicine imaging to better understand their specific distribution, uptake and retention in different in vivo cancer models. In addition, radiolabeled gold nanoparticles enable image-guided therapy is reviewed as well as the enhancement of targeted radionuclide therapy and nanobrachytherapy through an increased dose deposition and radiosensitization, as demonstrated by multiple Monte Carlo studies and experimental in vitro and in vivo studies.

Solid-phase extraction methods for nucleic acid separation. A review

The separation and purification of biomacromolecules such as nucleic acid is a perpetual topic in separation processes and bioengineering (fine chemicals, biopharmaceutical engineering, diagnostics, and biological characterization). In principle, the solid-phase extraction for nucleic acid exhibits efficient phase separation, low pollution risk, and small sample demand, compared to the conventional liquid-phase extraction. Herein, solid-phase extraction methods are systematically reviewed to outline research progress and explore additional solid-phase sorbents and devices for novel, flexible, and high-efficiency nucleic acid separation processes. The functional materials capture nucleic acid, magnetic and magnetic-free solid-phase extraction methods, separation device design and optimization, and high-throughput automatable applications based on high-performance solid-phase extraction are summarized. Finally, the current challenges and promising topics are discussed.

Gold Nanoparticles Dissolve Extracellularly in the Presence of Human Macrophages

INTRODUCTION

Gold nanoparticles (AuNPs) have the potential to be used in various biomedical applications, partly due to the inertness and stability of gold. Upon intravenous injection, the NPs interact with the mononuclear phagocyte system, first with monocytes in the blood and then with macrophages in tissue. The NP-macrophage interaction will likely affect the stability of the AuNPs, but this is seldom analyzed. This study aimed to elucidate the role of macrophages in the biodissolution of AuNPs and underlying mechanisms.

METHODS

With an in vitro dissolution assay, we used inductively coupled plasma mass spectrometry to quantitatively compare the dissolution of 5 and 20 nm AuNPs coated with citrate or PEG in cell medium alone or in the presence of THP1-derived macrophages at 24 hours. In addition, we analyzed the cell dose, compared extra- and intracellular dissolution, and explored the possible role of reactive nitrogen species.

RESULTS

The results showed a higher cellular dose of the citrate-coated AuNPs, but dissolution was mainly evident for those sized 5 nm, irrespective of coating. The macrophages clearly assisted the dissolution, which was approximately fivefold higher in the presence of macrophages. The dissolution, however, appeared to take place mainly extracellularly. Acellular experiments demonstrated that peroxynitrite can initiate oxidation of gold, but a ligand is required to keep the gold ions in solution.

CONCLUSION

This study suggests extracellular dissolution of AuNPs in the presence of macrophages, likely with the contribution of the release of reactive nitrogen species, and provides new insight into the fate of AuNPs in the body.

The application prospect of metal/metal oxide nanoparticles in the treatment of osteoarthritis

The current understanding of osteoarthritis is developing from a mechanical disease caused by cartilage wear to a complex biological response involving inflammation, oxidative stress and other aspects. Nanoparticles are widely used in drug delivery due to its good stability in vivo and cell uptake efficiency. In addition to the above advantages, metal/metal oxide NPs, such as cerium oxide and manganese dioxide, can also simulate the activity of antioxidant enzymes and catalyze the degradation of superoxide anions and hydrogen peroxide. Degrading of metal/metal oxide nanoparticles releases metal ions, which may slow down the progression of osteoarthritis by inhibiting inflammation, promoting cartilage repair and inhibiting cartilage ossification. In present review, we focused on recent research works concerning osteoarthritis treating with metal/metal oxide nanoparticles, and introduced some potential nanoparticles that may have therapeutic effects.

Nanotherapeutic approach to tackle chemotherapeutic resistance of cancer stem cells

Estimates indicate that cancer will become the leading cause of mortality worldwide in the future. Tumorigenesis is a complex process that involves self-sufficiency in signs of growth, insensitivity to anti-growth signals, prevention of apoptosis, unlimited replication, sustained angiogenesis, tissue invasion, and metastasis. Cancer stem cells (CSCs) have an important role in tumor development and resistance. Here we will approach phenotypic plasticity capacity, highly efficient DNA repair systems, anti-apoptotic machinery, sustained stemness features, interaction with the tumor microenvironment, and Notch, Wnt, and Hedgehog signaling pathways. The researches about CSCs as a target in cancer treatment has been growing. Many different options have pointed beneficial results, such as pathways and CSC-surface markers targeting. Besides its limitations, nanotherapeutics have emerged as a potential strategy in this context since they aim to improve pharmacokinetics, biodistribution, and reduce the side effects observed in traditional treatments. Nanoparticles have been studied in this field, mostly for drug delivery and a multitherapy approach. Another widely researched approaches in this area are related to heat therapy, such as photothermal therapy, photodynamic therapy and magnetic hyperthermia, besides molecular targeting. This review will contemplate the most relevant studies that have shown the effects of nanotherapeutics. In conclusion, although the studies analyzed are mostly preclinical, we believe that there is strong evidence that nanoparticles can increase the chances of a better prognosis to cancer in the future. It is also essential to transpose these findings to the clinic to confirm and better understand the role of nanotherapeutics in this context.

The Role of LncRNAs in Uveal Melanoma

Uveal melanoma (UM) is an intraocular cancer tumor with high metastatic risk. It is considered a rare disease, but 90% of affected patients die within 15 years. Non-coding elements (ncRNAs) such as long non-coding RNAs (lncRNAs) have a crucial role in cellular homeostasis maintenance, taking part in many critical cellular pathways. Their deregulation, therefore, contributes to the induction of cancer and neurodegenerative and metabolic diseases. In cancer, lncRNAs are implicated in apoptosis evasion, proliferation, invasion, drug resistance, and other roles because they affect tumor suppressor genes and oncogenes. For these reasons, lncRNAs are promising targets in personalized medicine and can be used as biomarkers for diseases including UM.

Molecular Imaging of Cardiovascular Inflammation

Cardiovascular diseases (CVD), including atherosclerosis, are chronic inflammatory diseases characterised by a complex and evolving tissue micro-environment. Molecular heterogeneity of inflammatory responses translates into clinical outcomes. However, current medical imaging modalities are unable to reveal the cellular and molecular events at a level of detail that would allow more accurate and timely diagnosis and treatment. This is an inherent limitation of the current imaging tools which are restricted to anatomical or functional data. Molecular imaging - the visualization and quantification of molecules in the body - is already established in the clinic in the form of Positron Emitted Tomography (PET), yet the use of PET in CVD is limited. In this visual review, we will guide you through the current state of molecular imaging research, assessing the respective strengths and weaknesses of molecular imaging modalities, including those already being used in the clinic such as PET and magnetic resonance imaging (MRI) and emerging technologies at pre-clinical stage, such as photoacoustic imaging. We discuss the basic principles of each technology and provide key examples of their application in imaging inflammation in CVD and the added value into the diagnostic decision-making process. Finally, we discuss barriers for rapid successful clinical translation of these novel diagnostic modalities.

Biosynthesis of Silver Nanoparticles from Citrobacter freundii as Antibiofilm Agents with their Cytotoxic Effects on Human Cells

BACKGROUND

Nanomaterials have recently been identified for their potential benefits in the areas of medicine and pharmaceuticals. Among these nanomaterials, silver nanoparticles (Ag-NPs) have been widely utilized in the fields of diagnostics, antimicrobials, and catalysis.

OBJECTIVE

To investigate the potential utility of Citrobacter freundii in the synthesis of silver Nanoparticles (Ag-NPs), and to determine the antimicrobial activities of the Ag-NPs produced.

METHODS

Aqueous Ag+ ions were reduced when exposed to C. freundii extract and sunlight, leading to the formation of Ag-NPs. Qualitative microanalysis for the synthesized Ag-NPs was done using UVvis spectrometry, Energy Dispersive X-ray analysis (EDX), and scanning and transmission electron microscopy. The hydrodynamic size and stability of the particles were detected using Dynamic Light Scattering (DLS) analysis. The Ag-NPs' anti-planktonic and anti-biofilm activities against Staphylococcus aureus and Pseudomonas aeruginosa, which are two important skin and wound pathogens, were investigated. The cytotoxicity on human dermal fibroblast cell line was also determined.

RESULTS

Ag-NPs were spherical with a size range between 15 to 30 nm. Furthermore, Ag-NPs displayed potent bactericidal activities against both S. aureus and P. aeruginosa and showed noticeable anti-biofilm activity against S. aureus biofilms. Ag-NPs induced minor cytotoxic effects on human cells as indicated by a reduction in cell viability, a disruption of plasma membrane integrity, and apoptosis induction.

CONCLUSION

Ag-NPs generated in this study might be a future potential alternative to be used as antimicrobial agents in pharmaceutical applications for wound and skin related infections.

Current Biomedical and Diagnostic Applications of Gold Micro and Nanoparticles

Production of particles and their adaptation in the pharmacology became an object of interest, and they are the currently introduced therapies based on the use of micro and nanoparticles. The use of gold particles is not an exception. This review has focused on the application of gold micro and nanoparticles in pharmacology and biomedicine. The particles can be used for diagnosis respective theranostic of cancer, rheumatoid arthritis and as antimicrobial means. Besides these applications, specifications of gold, gold particles, and colloidal gold manufacturing and their comparison with the solid gold, are described as well. This review is based on a survey of actual scientific literature.

Gold Nanoparticles; Potential Nanotheranostic Agent in Breast Cancer: A Comprehensive Review with Systematic Search Strategy

BACKGROUND

Breast cancer is a heterogeneous disease typically prevalent among women and is the second-largest cause of death worldwide. Early diagnosis is the key to minimize the cancer-induced complication, however, the conventional diagnostic strategies have been sluggish, complex, and, to some extent, non-specific. Therapeutic tools are not so convenient and side effects of current therapies offer the development of novel theranostic tool to combat this deadly disease.

OBJECTIVE

This article aims to summarize the advances in the diagnosis and treatment of breast cancer with gold nanoparticles (GNP or AuNP).

METHODS

A systematic search was conducted in the three popular electronic online databases including PubMed, Google Scholar, and Web of Science, regarding GNP as breast cancer theranostics.

RESULTS

Published literature demonstrated that GNPs tuned with photosensitive moieties, nanomaterials, drugs, peptides, nucleotide, peptides, antibodies, aptamer, and other biomolecules improve the conventional diagnostic and therapeutic strategies of breast cancer management with minimum cytotoxic effect. GNP derived diagnosis system assures reproducibility, reliability, and accuracy cost-effectively. Additionally, surface-modified GNP displayed theranostic potential even in the metastatic stage of breast cancer.

CONCLUSION

Divergent strategies have shown the theranostic potential of surface tuned GNPs against breast cancer even in the metastatic stage with minimum cytotoxic effects both in vitro and in vivo.

Various theranostics and immunization strategies based on nanotechnology against Covid-19 pandemic: An interdisciplinary view

COVID-19 pandemic is still a major risk to human civilization. Besides the global immunization policy, more than five lac new cases are documented everyday. Some countries newly implement partial/complete nationwid lockdown to mitigate recurrent community spreading. To avoid the new modified stain of SARS-CoV-2 spreading, some countries imposed any restriction on the movement of the citizens within or outside the country. Effective economical point of care diagnostic and therapeutic strategy is vigorously required to mitigate viral spread. Besides struggling with repurposed medicines, new engineered materials with multiple unique efficacies and specific antiviral potency against SARS-CoV-2 infection may be fruitful to save more lives. Nanotechnology-based engineering strategy sophisticated medicine with specific, effective and nonhazardous delivery mechanism for available repurposed antivirals as well as remedial for associated diseases due to malfeasance in immuno-system e.g. hypercytokinaemia, acute respiratory distress syndrome. This review will talk about gloomy but critical areas for nanoscientists to intervene and will showcase about the different laboratory diagnostic, prognostic strategies and their mode of actions. In addition, we speak about SARS-CoV-2 pathophysiology, pathogenicity and host specific interation with special emphasis on altered immuno-system and also perceptualized, copious ways to design prophylactic nanomedicines and next-generation vaccines based on recent findings.

Radiosensitization Effect of Gold Nanoparticles in Proton Therapy

The number of proton therapy facilities and the clinical usage of high energy proton beams for cancer treatment has substantially increased over the last decade. This is mainly due to the superior dose distribution of proton beams resulting in a reduction of side effects and a lower integral dose compared to conventional X-ray radiotherapy. More recently, the usage of metallic nanoparticles as radiosensitizers to enhance radiotherapy is receiving growing attention. While this strategy was originally intended for X-ray radiotherapy, there is currently a small number of experimental studies indicating promising results for proton therapy. However, most of these studies used low proton energies, which are less applicable to clinical practice; and very small gold nanoparticles (AuNPs). Therefore, this proof of principle study evaluates the radiosensitization effect of larger AuNPs in combination with a 200 MeV proton beam. CHO-K1 cells were exposed to a concentration of 10 μg/ml of 50 nm AuNPs for 4 hours before irradiation with a clinical proton beam at NRF iThemba LABS. AuNP internalization was confirmed by inductively coupled mass spectrometry and transmission electron microscopy, showing a random distribution of AuNPs throughout the cytoplasm of the cells and even some close localization to the nuclear membrane. The combined exposure to AuNPs and protons resulted in an increase in cell killing, which was 27.1% at 2 Gy and 43.8% at 6 Gy, compared to proton irradiation alone, illustrating the radiosensitizing potential of AuNPs. Additionally, cells were irradiated at different positions along the proton depth-dose curve to investigate the LET-dependence of AuNP radiosensitization. An increase in cytogenetic damage was observed at all depths for the combined treatment compared to protons alone, but no incremental increase with LET could be determined. In conclusion, this study confirms the potential of 50 nm AuNPs to increase the therapeutic efficacy of proton therapy.

Design and Encapsulation of Immunomodulators onto Gold Nanoparticles in Cancer Immunotherapy

The aim of cancer immunotherapy is to reactivate autoimmune responses to combat cancer cells. To stimulate the immune system, immunomodulators, such as adjuvants, cytokines, vaccines, and checkpoint inhibitors, are extensively designed and studied. Immunomodulators have several drawbacks, such as drug instability, limited half-life, rapid drug clearance, and uncontrolled immune responses when used directly in cancer immunotherapy. Several strategies have been used to overcome these limitations. A simple and effective approach is the loading of immunomodulators onto gold-based nanoparticles (GNPs). As gold is highly biocompatible, GNPs can be administered intravenously, which aids in increasing cancer cell permeability and retention time. Various gold nanoplatforms, including nanospheres, nanoshells, nanorods, nanocages, and nanostars have been effectively used in cancer immunotherapy. Gold nanostars (GNS) are one of the most promising GNP platforms because of their unusual star-shaped geometry, which significantly increases light absorption and provides high photon-to-heat conversion efficiency due to the plasmonic effect. As a result, GNPs are a useful vehicle for delivering antigens and adjuvants that support the immune system in killing tumor cells by facilitating or activating cytotoxic T lymphocytes. This review represents recent progress in encapsulating immunomodulators into GNPs for utility in a cancer immunotherapeutic regimen.

Green Synthesis of Gold Nano-bioconjugates from Onion Peel Extract and Evaluation of Their Antioxidant, Anti-inflammatory, and Cytotoxic Studies

Plant secondary metabolites such as flavonoids demonstrate high degrees of antioxidant, anti-inflammatory, and anticancer activities. Among flavonoids, quercetin plays an important role in inflammation by downregulating the level of various cytokines. Thereby, in this work, onion (Allium cepa) peel was successfully utilized for the synthesis of gold nano-bioconjugates acting as a natural therapeutic drug. In this process, crude onion peel extract was first divided into different fractionates, namely, ethyl acetate, butanol, methanol, and water, and they were subjected to various preliminary studies of antioxidant activities. The ethyl acetate fractionate shows high antioxidant activities in all the assays. The bioactive components were identified and found to contain a high amount of quercetin as confirmed by liquid chromatography with tandem mass spectrometry and high-performance liquid chromatogrpahy. Three gold nano-bioconjugates were prepared with different concentrations of the ethyl acetate fractionate. Various biochemical anti-inflammatory assays were carried out and compared with the active ethyl acetate fraction of the onion peel drug (OPD). The cytotoxicity of the nano-bioconjugate system and the OPD was checked in the myoblast L6 cell line from skeletal muscle tissues to evaluate the toxicity. All the three nano-bioconjugates A, B, and E demonstrated high percentages of cell viability, viz., 73.07, 72.3, and 69.15%, respectively, at their highest concentration of 200 μg/mL. The OPD also showed 88.56% cell viability with no toxic effects in the myoblast L6 cell line from skeletal muscle tissues. The reactive oxygen species reduction of nano-bioconjugate B showed a marked reduction of 76.77% at a maximum concentration of 200 μg/mL, whereas the OPD showed 68.17%. Hence, through this work, a cheap source of nano-bioconjugates is developed, which can act as a potent antioxidant and anti-inflammatory agent and are more active in comparison to the OPD alone.

Phosphatidylserine-Gold Nanoparticles (PS-AuNP) Induce Prostate and Breast Cancer Cell Apoptosis

Prostate and breast cancer are the current leading causes of new cancer cases in males and females, respectively. Phosphatidylserine (PS) is an essential lipid that mediates macrophage efferocytosis and is dysregulated in tumors. Therefore, developing therapies that selectively restore PS may be a potential therapeutic approach for carcinogenesis. Among the nanomedicine strategies for delivering PS, biocompatible gold nanoparticles (AuNPs) have an extensive track record in biomedical applications. In this study, we synthesized biomimetic phosphatidylserine-caped gold nanoparticles (PS-AuNPs) and tested their anticancer potential in breast and prostate cancer cells in vitro. We found that both cell lines exhibited changes in cell morphology indicative of apoptosis. After evaluating for histone-associated DNA fragments, a hallmark of apoptosis, we found significant increases in DNA fragmentation upon PS-AuNP treatment compared to the control treatment. These findings demonstrate the use of phosphatidylserine coupled with gold nanoparticles as a potential treatment for prostate and breast cancer. To the best of our knowledge, this is the first time that a phosphatidylserine-capped AuNP has been examined for its therapeutic potential in cancer therapy.

Recent advances in bionanomaterials for liver cancer diagnosis and treatment

According to the World Health Organization, liver cancer is the fourth leading cause of cancer associated with death worldwide. It demands effective treatment and diagnostic strategies to hinder its recurrence, complexities, aggressive metastasis and late diagnosis. With recent progress in nanotechnology, several nanoparticle-based diagnostic and therapeutic modalities have entered into clinical trials. With further developments in nanoparticle mediated liver cancer diagnosis and treatment, the approach holds promise for improved clinical liver cancer management. In this review, we discuss the key advances in nanoparticles that have potential for liver cancer diagnosis and treatment. We also discuss the potential of nanoparticles to overcome the limitations of existing therapeutic modalities.

The Nanosystems Involved in Treating Lung Cancer

Even though there are various types of cancer, this pathology as a whole is considered the principal cause of death worldwide. Lung cancer is known as a heterogeneous condition, and it is apparent that genome modification presents a significant role in the occurrence of this disorder. There are conventional procedures that can be utilized against diverse cancer types, such as chemotherapy or radiotherapy, but they are hampered by the numerous side effects. Owing to the many adverse events observed in these therapies, it is imperative to continuously develop new and improved strategies for managing individuals with cancer. Nanomedicine plays an important role in establishing new methods for detecting chromosomal rearrangements and mutations for targeted chemotherapeutics or the local delivery of drugs via different types of nano-particle carriers to the lungs or other organs or areas of interest. Because of the complex signaling pathways involved in developing different types of cancer, the need to discover new methods for prevention and detection is crucial in producing gene delivery materials that exhibit the desired roles. Scientists have confirmed that nanotechnology-based procedures are more effective than conventional chemotherapy or radiotherapy, with minor side effects. Several nanoparticles, nanomaterials, and nanosystems have been studied, including liposomes, dendrimers, polymers, micelles, inorganic nanoparticles, such as gold nanoparticles or carbon nanotubes, and even siRNA delivery systems. The cytotoxicity of such nanosystems is a debatable concern, and nanotechnology-based delivery systems must be improved to increase the bioavailability, biocompatibility, and safety profiles, since these nanosystems boast a remarkable potential in many biomedical applications, including anti-tumor activity or gene therapy. In this review, the nanosystems involved in treating lung cancer and its associated challenges are discussed.

AuNP Coupled Rapid Flow-Through Dot-Blot Immuno-Assay for Enhanced Detection of SARS-CoV-2 Specific Nucleocapsid and Receptor Binding Domain IgG

BACKGROUND

Serological tests detecting severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are widely used in seroprevalence studies and evaluating the efficacy of the vaccination program. Some of the widely used serological testing techniques are enzyme-linked immune-sorbent assay (ELISA), chemiluminescence immunoassay (CLIA), and lateral flow immunoassay (LFIA). However, these tests are plagued with low sensitivity or specificity, time-consuming, labor-intensive, and expensive. We developed a serological test implementing flow-through dot-blot assay (FT-DBA) for SARS-CoV-2 specific IgG detection, which provides enhanced sensitivity and specificity while being quick to perform and easy to use.

METHODS

SARS-CoV-2 antigens were immobilized on nitrocellulose membrane to capture human IgG, which was then detected with anti-human IgG conjugated gold nanoparticle (hIgG-AuNP). A total of 181 samples were analyzed in-house. Within which 35 were further evaluated in US FDA-approved CLIA Elecsys SARS-CoV-2 assay. The positive panel consisted of RT-qPCR positive samples from patients with both <14 days and >14 days from the onset of clinical symptoms. The negative panel contained samples collected from the pre-pandemic era dengue patients and healthy donors during the pandemic. Moreover, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FT-DBA were evaluated against RT-qPCR positive sera. However, the overall efficacies were assessed with sera that seroconverted against either nucleocapsid (NCP) or receptor-binding domain (RBD).

RESULTS

In-house ELISA selected a total of 81 true seropositive and 100 seronegative samples. The sensitivity of samples with <14 days using FT-DBA was 94.7%, increasing to 100% for samples >14 days. The overall detection sensitivity and specificity were 98.8% and 98%, respectively, whereas the overall PPV and NPV were 99.6% and 99%. Moreover, comparative analysis between in-house ELISA assays and FT-DBA revealed clinical agreement of Cohen's Kappa value of 0.944. The FT-DBA showed sensitivity and specificity of 100% when compared with commercial CLIA kits.

CONCLUSION

The assay can confirm past SARS-CoV-2 infection with high accuracy within 2 minutes compared to commercial CLIA or in-house ELISA. It can help track SARS-CoV-2 disease progression, population screening, and vaccination response. The ease of use of the assay without requiring any instruments while being semi-quantitative provides the avenue of its implementation in remote areas around the globe, where conventional serodiagnosis is not feasible.

Extracellular Vesicles as Mediators of Cancer Disease and as Nanosystems in Theranostic Applications

Cancer remains a leading cause of death worldwide despite decades of intense efforts to understand the molecular underpinnings of the disease. To date, much of the focus in research has been on the cancer cells themselves and how they acquire specific traits during disease development and progression. However, these cells are known to secrete large numbers of extracellular vesicles (EVs), which are now becoming recognized as key players in cancer. EVs contain a large number of different molecules, including but not limited to proteins, mRNAs, and miRNAs, and they are actively secreted by many different cell types. In the last two decades, a considerable body of evidence has become available indicating that EVs play a very active role in cell communication. Cancer cells are heterogeneous, and recent evidence reveals that cancer cell-derived EV cargos can change the behavior of target cells. For instance, more aggressive cancer cells can transfer their "traits" to less aggressive cancer cells and convert them into more malignant tumor cells or, alternatively, eliminate those cells in a process referred to as "cell competition". This review discusses how EVs participate in the multistep acquisition of specific traits developed by tumor cells, which are referred to as "the hallmarks of cancer" defined by Hanahan and Weinberg. Moreover, as will be discussed, EVs play an important role in drug resistance, and these more recent advances may explain, at least in part, why pharmacological therapies are often ineffective. Finally, we discuss literature proposing the use of EVs for therapeutic and prognostic purposes in cancer.

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

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

Emerging nanomaterials for antibacterial textile fabrication

In recent times, the search for innovative material to fabricate smart textiles has been increasing to satisfy the expectation and needs of the consumers, as the textile material plays a key role in the evolution of human culture. Further, the textile materials provide an excellent environment for the microbes to grow, because of their large surface area and ability to retain moisture. In addition, the growth of harmful bacteria on the textile material not only damages them but also leads to intolerable foul odour and significant danger to public health. In particular, the pathogenic bacteria present in the fabric surface can cause severe skin infections such as skin allergy and irritation via direct human contact and even can lead to heart problems and pneumonia in certain cases. Recently, nanoparticles and nanomaterials play a significant role in textile industries for developing functional smart textiles with self-cleaning, UV-protection, insect repellent, waterproof, anti-static, flame-resistant and antimicrobial-resistant properties. Thus, this review is an overview of various textile fibres that favour bacterial growth and potential antibacterial nanoparticles that can inhibit the growth of bacteria on fabric surfaces. In addition, the probable antibacterial mechanism of nanoparticles and the significance of the fabric surface modification and fabric finishes in improving the long-term antibacterial efficacy of nanoparticle-coated fabrics were also discussed.

Recent perspectives of nanotechnology in burn wounds management: a review

OBJECTIVE

The burden of the management of problematic skin wounds characterised by a compromised skin barrier is growing rapidly. Almost six million patients are affected in the US alone, with an estimated market of $25 billion annually. There is an urgent requirement for efficient mechanism-based treatments and more efficacious drug delivery systems. Novel strategies are needed for faster healing by reducing infection, moisturising the wound, stimulating the healing mechanisms, speeding up wound closure and reducing scar formation.

METHODS

A systematic review of qualitative studies was conducted on the recent perspectives of nanotechnology in burn wounds management. Pubmed, Scopus, EMBASE, CINAHL and PsychINFO databases were all systematically searched. Authors independently rated the reporting of the qualitative studies included. A comprehensive literature search was conducted covering various resources up to 2018-2019. Traditional techniques aim to simply cover the wound without playing any active role in wound healing. However, nanotechnology-based solutions are being used to create multipurpose biomaterials, not only for regeneration and repair, but also for on-demand delivery of specific molecules. The chronic nature and associated complications of nonhealing wounds have led to the emergence of nanotechnology-based therapies that aim at facilitating the healing process and ultimately repairing the injured tissue.

CONCLUSION

Nanotechnology-based therapy is in the forefront of next-generation therapy that is able to advance wound healing of hard-to-heal wounds. In this review, we will highlight the developed nanotechnology-based therapeutic agents and assess the viability and efficacy of each treatment. Herein we will explore the unmet needs and future directions of current technologies, while discussing promising strategies that can advance the wound-healing field.

Atomically Precise Gold Nanoclusters: Towards an Optimal Biocompatible System from a Theoretical-Experimental Strategy

Potential biomedical applications of gold nanoparticles have increasingly been reported with great promise for diagnosis and therapy of several diseases. However, for such a versatile nanomaterial, the advantages and potential health risks need to be addressed carefully, as the available information about their toxicity is limited and inconsistent. Atomically precise gold nanoclusters (AuNCs) have emerged to overcome this challenge due to their unique features, such as superior stability, excellent biocompatibility, and efficient renal clearance. Remarkably, the elucidation of their structural and physicochemical properties provided by theory-experiment investigations offers exciting opportunities for site-specific biofunctionalization of the nanoparticle surface, which remains a significant concern for most of the materials in the biomedical field. This concept highlights the advantages conferred by atomically precise AuNCs for biomedical applications and the powerful strategy combining computational and experimental studies towards finding an optimal biocompatible AuNCs-based nanosystem.

Microfluidic formulation of nanoparticles for biomedical applications

Nanomedicine has made significant advances in clinical applications since the late-20th century, in part due to its distinct advantages in biocompatibility, potency, and novel therapeutic applications. Many nanoparticle (NP) therapies have been approved for clinical use, including as imaging agents or as platforms for drug delivery and gene therapy. However, there are remaining challenges that hinder translation, such as non-scalable production methods and the inefficiency of current NP formulations in delivering their cargo to their target. To address challenges with existing formulation methods that have batch-to-batch variability and produce particles with high dispersity, microfluidics-devices that manipulate fluids on a micrometer scale-have demonstrated enormous potential to generate reproducible NP formulations for therapeutic, diagnostic, and preventative applications. Microfluidic-generated NP formulations have been shown to have enhanced properties for biomedical applications by formulating NPs with more controlled physical properties than is possible with bulk techniques-such as size, size distribution, and loading efficiency. In this review, we highlight advances in microfluidic technologies for the formulation of NPs, with an emphasis on lipid-based NPs, polymeric NPs, and inorganic NPs. We provide a summary of microfluidic devices used for NP formulation with their advantages and respective challenges. Additionally, we provide our analysis for future outlooks in the field of NP formulation and microfluidics, with emerging topics of production scale-independent formulations through device parallelization and multi-step reactions within droplets.

Nanoparticles as Novel Emerging Therapeutic Antibacterial Agents in the Antibiotics Resistant Era

Microorganisms are highly resistant to the antibiotics that are commonly used and thus are becoming serious public health problem. There is an urgent need for new approaches to monitor microbial behavior, and hence, nanomaterial can be a very promising solution. Nanotechnology has led to generation of novel antimicrobial agents such as gold, silver, zinc, copper, poly-£-lysine, iron, and chitosan which have shown remarkable potential, demonstrating their applicability as proficient antibiotic agents against various pathogenic bacterial species. The antimicrobial nanoproduct physically kills the organism's cell membranes that prevent the production of drug-resistant microorganisms. These nanosized particles can also be used as diagnostic agents, targeted drug delivery vehicle, noninvasive imaging technologies, and in vivo visual monitoring of tumors angiogenesis. These nanomaterials provide a promising platform for diagnostics, prognostic, drug delivery, and treatment of diseases by means of nanoengineered products/devices. This owes to their small size, prolonged antimicrobial efficacy with insignificant toxicity creating less environmental hazard or toxicity. Scientists address several problems such as health, bioethical problems, toxicity risks, physiological, and pharmaceutical concerns related with the usage of NPs as antimicrobial agents as current research lack adequate data and information on the safe use of certain tools and materials.

Innovative Nanotechnology a Boon for Fight Against Pandemic COVID–19

COVID – 19 is a contagious disease caused by severe acute respiratory syndrome (SARS-CoV2). The rate at which COVID – 19-virus spread from epidemic to pandemic within a short period is quite alarming. As of July 2020, the Dashboard of the World Health Organization (WHO) recorded over 15 million COVID – 19 cases across 213 countries, with mortality of over 620,000. The governments and healthcare agencies responsible for mitigating the virus's spread have adopted several strategies to end the pandemic. However, all hands were on deck to establish the standard treatment modalities of SARS-CoV-2 through inventing new drugs, vaccine candidates, or repurposing the existing medicines and robust diagnostic tools, in addition to other technological innovations. Therefore, nanotechnology’s employment would play a vital role in bringing multidisciplinary ways of developing affordable, reliable, and powerful tools for diagnosis, in addition to personal protection and effective medicines. Additionally, nanosensors' application would significantly aid the diagnoses of the COVID–19 even on asymptomatic patients, and thus would be an essential means for determining its prevalence. Likewise, nanoscale fibers can optimize personal equipment protection and allow their reusability for medical and economic benefits. Accordingly, the literature was intensively reviewed by searching for the combinations of the research keywords in the official scientific databases such as Science Direct, PubMed, and Google Scholar. Hence, this research highlighted the perspective contributions of nanotechnology in the war against the COVID-19 pandemic.

Pharmacokinetics, Biodistribution, and Biosafety of PEGylated Gold Nanoparticles In Vivo

Despite the obvious advantages of gold nanoparticles for biomedical applications, controversial and incomplete toxicological data hamper their widespread use. Here, we present the results from an in vivo toxicity study using gold nanoparticles coated with polyethylene glycol (PEG-AuNPs). The pharmacokinetics and biodistribution of PEG-AuNPs were examined in the rat’s liver, lung, spleen, and kidney after a single i.v. injection (0.7 mg/kg) at different time intervals. PEG-AuNPs had a relatively long blood circulation time and accumulated primarily in the liver and spleen, where they remained for up to 28 days after administration. Increased cytoplasmic vacuolation in hepatocytes 24 h and 7 days after PEG-AuNPs exposure and apoptotic-like cells in white splenic pulp 24 h after administration has been detected, however, 28 days post-exposure were no longer observed. In contrast, at this time point, we identified significant changes in lipid metabolism, altered levels of liver injury markers, and elevated monocyte count, but without marked biological relevance. In blood cells, no DNA damage was present in any of the studied time intervals, with the exception of DNA breakage transiently detected in primary kidney cells 4 h post-injection. Our results indicate that the tissue accumulation of PEG-AuNPs might result in late toxic effects.

Enhancement of gold-nanocluster-mediated chemotherapeutic efficiency of cisplatin in lung cancer

A novel delivery system for cisplatin was constructed based on electrostatics-mediated assemblies of gold nanoclusters and PEGylated cationic peptide (cisplatin@GC-pKs). Encapsulated cisplatin in the as-formed micelle like assemblies was observed to demonstrate improved cellar uptake and enhanced chemotherapeutic efficiency in the cisplatin-resistant lung cancer cells. In vivo assays further confirmed that cisplatin@GC-pKs had profound anti-tumor efficiency due to deep penetration and accumulation of nanoscale cisplatin@GC-pKs via the enhanced permeability and retention (EPR) effect at tumor tissues. The constructed cisplatin@GC-pKs in this work demonstrated enhanced anti-tumor activity for lung cancer therapy, as well as a potential treatment strategy for a variety of cisplatin-resistance related malignancies.

Nanoparticle-Cartilage Interaction: Pathology-Based Intra-articular Drug Delivery for Osteoarthritis Therapy

Osteoarthritis is the most prevalent chronic and debilitating joint disease, resulting in huge medical and socioeconomic burdens. Intra-articular administration of agents is clinically used for pain management. However, the effectiveness is inapparent caused by the rapid clearance of agents. To overcome this issue, nanoparticles as delivery systems hold considerable promise for local control of the pharmacokinetics of therapeutic agents. Given the therapeutic programs are inseparable from pathological progress of osteoarthritis, an ideal delivery system should allow the release of therapeutic agents upon specific features of disorders. In this review, we firstly introduce the pathological features of osteoarthritis and the design concept for accurate localization within cartilage for sustained drug release. Then, we review the interactions of nanoparticles with cartilage microenvironment and the rational design. Furthermore, we highlight advances in the therapeutic schemes according to the pathology signals. Finally, armed with an updated understanding of the pathological mechanisms, we place an emphasis on the development of "smart" bioresponsive and multiple modality nanoparticles on the near horizon to interact with the pathological signals. We anticipate that the exploration of nanoparticles by balancing the efficacy, safety, and complexity will lay down a solid foundation tangible for clinical translation.

Physical properties of gold nanoparticles affect skin penetration via hair follicles

Drug penetration through the skin is significant for both transdermal and dermal delivery. One mechanism that has attracted attention over the last two decades is the transport pathway of nanoparticles via hair follicle, through the epidermis, directly to the pilosebaceous unit and blood vessels. Studies demonstrate that particle size is an important factor for drug penetration. However, in order to gain more information for the purpose of improving this mode of drug delivery, a thorough understanding of the optimal physical particle properties is needed. In this study, we fabricated fluorescently labeled gold nanoparticles (GNP) with a tight control over the size and shape. The effect of the particles' physical parameters on follicular penetration was evaluated histologically. We used horizontal human skin sections and found that the optimal size for polymeric particles is 0.25 μm. In addition, shape penetration experiments revealed gold nanostars' superiority over spherical particles. Our findings suggest the importance of the particles' physical properties in the design of nanocarriers delivered to the pilosebaceous unit.

Cytotoxicity and Cellular Death Modality of Surface-Decorated Gold Nanorods against a Panel of Breast Cancer Cell Lines

Herein, the antiproliferative effect of surface-decorated gold nanorods (GNRs) was investigated against three different breast cancer cell lines. The results indicate that the cell lines exhibited different biological responses and death modalities toward the treatment. The cell lines exhibited similar cellular uptake of the nanoparticles; however, MDA-MB-231 demonstrated the highest cytotoxicity compared to other cell lines upon treatment with GNRs. The expression of the CDH1 gene, which is involved in cell adhesion and metastasis, was dramatically increased in treated MDA-MB-231 cells compared to other cell lines. Early apoptosis and late apoptosis are the dominant cellular death modalities of MDA-MB-231 cells upon treatment with GNRs.

A deep learning approach to gold nanoparticle quantification in computed tomography

INTRODUCTION

Deep learning (DL) is used to classify, detect, and quantify gold nanoparticles (AuNPs) in a human-sized phantom with a clinical MDCT scanner.

METHODS

AuNPs were imaged at concentrations between 0.0274 and 200 mgAu/mL in a 33 cm phantom. 1 mm-thick CT image slices were acquired at 120 kVp with a CTDI_vol of 23.6 mGy. A convolutional neural network (CNN) was trained on 544 images to classify 17 different tissue types and AuNP concentrations. A second set of 544 images was then used for testing.

RESULTS

AuNPs were classified with 95% accuracy at 0.1095 mgAu/mL and 97% accuracy at 0.2189 mgAu/mL. Both these concentrations are lower than what humans can visually perceive (0.3-1.4 mgAu/mL). AuNP concentrations were also classified with 95% accuracy at 150 and 200 mgAu/mL. These high concentrations result in CT numbers that are at or above the 12-bit limit for CT's dynamic range where extended Hounsfield scales are otherwise required for measuring differences in contrast.

CONCLUSIONS

We have shown that DL can be used to detect AuNPs at concentrations lower than what humans can visually perceive and can also quantify very high AuNP concentrations that exceed the typical 12-bit dynamic range of clinical MDCT scanners. This second finding is possible due to inhomogeneous AuNP distributions and characteristic streak artifacts. It may even be possible to extend this approach beyond AuNP imaging in CT for quantifying high density objects without extended Hounsfield scales.

Treating colon cancers with a non-conventional yet strategic approach: An overview of various nanoparticulate systems

Regardless of progress in therapy management which are developed for colon cancer (CC), it remains the third most common cause of mortality due to cancers around the world. Conventional medicines pose side effects due to untoward action on non-target cells. Their inability to deliver drugs to the affected regions of the colon locally, in a reproducible manner raises a concern towards the efficacy of therapy. In this regard, nanoparticles emerged as a promising drug delivery system due to their flexibility in designing, drug release modulation and cancer cell targeting. Not only are nanoparticles making their way into colon cancer research in the revolution of conventional onco-therapeutics, but they also offer promising scope in the development of colon cancer vaccines and theranostic tools. However, there are challenges with respect to drug delivery using nanoparticles, which may hamper the delivery of these novel carriers to the colon. The present review addresses recent advents in nanotechnology for colon-specific drug delivery (CDDS) which may help to overcome the existing challenges and intends to recognize futuristic potentials in the treatment of CC with CDDS.

Nanoparticle-based fluorescence probe for detection of NF-κB transcription factor in single cell via steric hindrance

A novel nanoparticle-based fluorescence probe was developed for NF-κB transcription factor detection and in situ imaging via steric hindrance. The probe contains gold nanoparticles (AuNPs) to quench fluorescence, and nucleic acids immobilized on the surface of AuNPs to output fluorescence. In the basal state, Cy5 labeled DNA1 folds its long chain into a hairpin structure and quenches fluorescence by forcing the Cy5 fluorophore close to the surface of AuNPs. After the probe enters the cell, the NF-κB transcription factor can bind to the κB site in the DNA duplex of the nucleic acids. The steric hindrance caused by NF-κB leads to the extension of the long chain of DNA1 and the removal of the Cy5 fluorophore from the surface of AuNPs, thereby restoring the fluorescence of the probe. By measuring NF-κB in cell lysis in vitro, the probe obtains a detection limit of 0.38 nM and the linear range from 0.5 to 16 nM. Repeated measurements showed the recovery in the cell nuclear extract was between 93.38 and 109.32%, with relative standard deviation less than 5%. By monitoring the sub-localization of the Cy5 fluorophore in single cell, the probe system can effectively distinguish active NF-κB (nucleus) and inactive NF-κB (cytoplasm) through in situ imaging. The well-designed probe will make up for the shortcomings of the existing technology, and reveal the regulatory role of transcription factors in many disease processes.

Recent Advances in Hollow Gold Nanostructures for Biomedical Applications

The localized surface plasmon resonance of metallic nanoparticles has attracted much attention owing to its unique characteristics, including the enhancement of signals in sensors and photothermal effects. In particular, hollow gold nanostructures are highly promising for practical applications, with significant advantages being found in their material properties and structures: 1) the interaction between the outer surface plasmon mode and inner cavity mode leads to a greater resonance, allowing it to absorb near-infrared light, which can readily penetrate tissue; 2) it has anti-corrosiveness and good biocompatibility, which makes it suitable for biomedical applications; 3) it shows a reduced net density and large surface area, allowing the possibility of nanocarriers for drug delivery. In this review, we present information on the classification, characteristics, and synthetic methods of hollow gold nanostructures; discuss the recent advances in hollow gold nanostructures in biomedical applications, including biosensing, bioimaging, photothermal therapy, and drug delivery; and report on the existing challenges and prospects for hollow gold nanostructures.

The Application of and Strategy for Gold Nanoparticles in Cancer Immunotherapy

Immunotherapy of malignant tumor is a verified and crucial anti-tumor strategy to help patients with cancer for prolonging prognostic survival. It is a novel anticancer tactics that activates the immune system to discern and damage cancer cells, thereby prevent them from proliferating. However, immunotherapy still faces many challenges in view of clinical efficacy and safety issues. Various nanomaterials, especially gold nanoparticles (AuNPs), have been developed not only for anticancer treatment but also for delivering antitumor drugs or combining other treatment strategies. Recently, some studies have focused on AuNPs for enhancing cancer immunotherapy. In this review, we summarized how AuNPs applicated as immune agents, drug carriers or combinations with other immunotherapies for anticancer treatment. AuNPs can not only act as immune regulators but also deliver immune drugs for cancer. Therefore, AuNPs are candidates for enhancing the efficiency and safety of cancer immunotherapy.

Radioactive Gold Nanoparticle in Two Forms (¹⁹⁸₇₉Au GNPs and ^99mTc-GNPs) for Lung Cancer Antiproliferative Induction and Intralesional Imaging: A Proof of Concept

BACKGROUND

Lung cancer is among the most common cancers worldwide, responsible for 13% of all new cancer cases. Also, it is the leading cause of cancer death among both men and women. In this scenario, an effective and efficient treatment is required.

OBJECTIVE

Production of two gold nanoparticles: 198Au and 99mTc-Au. The first one has been produced from irradiation of the 197Au in order to produce a beta-emitter gold nanoparticle for cancer therapy. The second one has been produced from the radiolabeling of gold nanoparticles with technetium 99 metastable in order to produce imaging nanoagent.

METHODS

The 198Au nanoparticles were produced by irradiation and identified by hyper-purity germanium (HPGe). They were then evaluated in vitro in order to confirm the behavior on cell proliferation of lung cancer cell lines by the MTT methodology using A549 cells. The 99mTc-Au nanoparticles were produced by directradiolabeling with 99mTc and evaluated in vivo as intralesional nanoagent.

RESULTS

The results showed that in both cases, all the nanoparticles have performed their duties with excellence. The 198Au nanoparticles were capable to kill lung cancer cells, while 99mTc-Au was capable to image the tumor after intralesional injection. In addition, 99mTc-Au nanoparticles were useful for biodistribution assay imaging, showing the main organs responsible for the nanoparticle uptake in healthy animals.

CONCLUSION

Both gold nanoparticles showed to be a highly efficient nanoagent for both: therapy and diagnosing of lung cancer.