Probing the biological obstacles of nanomedicine with gold nanoparticles

Prospect of Gold Nanoparticles in Pancreatic Cancer

Pancreatic cancer (PC) is characterized by its notably poor prognosis and high mortality rate, underscoring the critical need for advancements in its diagnosis and therapy. Gold nanoparticles (AuNPs), with their distinctive physicochemical characteristics, demonstrate significant application potential in cancer therapy. For example, upon exposure to lasers of certain wavelengths, they facilitate localized heating, rendering them extremely effective in photothermal therapy. Additionally, their extensive surface area enables the conjugation of therapeutic agents or targeting molecules, increasing the accuracy of drug delivery systems. Moreover, AuNPs can serve as radiosensitizers, enhancing the efficacy of radiotherapy by boosting the radiation absorption in tumor cells. Here, we systematically reviewed the application and future directions of AuNPs in the diagnosis and treatment of PC. Although AuNPs have advantages in improving diagnostic and therapeutic efficacy, as well as minimizing damage to normal tissues, concerns about their potential toxicity and safety need to be comprehensively evaluated.

Harnessing barley grains for green synthesis of gold and silver nanoparticles with antibacterial potential

The continuous evolution and significance of green resources-based nanomaterials have spurred the exploration of sustainable sources for nanoparticle production. Green synthesis routes offer eco-friendly methodologies, ensuring nanoparticle stability and monodispersity, enhancing their efficiency for various applications. Notably, the thick biological corona layer surrounding nanoparticles (NPs) synthesized through green routes contributes to their unique properties. Consequently, there has been a surge in the development of NPs synthesis methods utilizing medicinal plants and diverse agricultural and waste resources. This study highlights the sustainable potential of barley grains for the synthesis of gold nanoparticles (Barley-AuNPs) and silver nanoparticles (Barley-AgNPs) as an environmentally friendly alternative, followed by NPs characterizations and their application against pathogenic bacteria: Escherichia coli UTI 89 and Pseudomonas aeruginosa PAO1. The rapid synthesis of Barley-AuNPs within 20 min and Barley-AgNPs within 30 min at 90 °C underscores the efficiency of barley as a green precursor. Characterization through advanced techniques, including SEM, TEM, EDS, AFM, DLS, FT-IR, MALDI-TOF, and sp-ICPMS, reveals the 20-25 nm size for Barley-AuNPs, while Barley-AgNPs demonstrate 2-10 nm size with spherical monodispersity. A notable contribution lies in the stability of these NPs over extended periods, attributed to a thick biological corona layer. This corona layer, which enhances stability, also influences the antimicrobial activity of Barley-AgNPs, presenting an intriguing trade-off. The antimicrobial investigations highlight the significant potential of Barley-AgNPs, with distinct minimum bactericidal concentrations (MBC) against P. aeruginosa and E. coli at 8 µg/mL. Overall, this research pioneers the use of barley grains for nanoparticle synthesis and unveils these nanoparticles' unique characteristics and potential antibacterial applications, contributing to the evolving landscape of sustainable nanotechnology.

Investigating the Effect of Surface Hydrophilicity on the Destiny of PLGA-Poloxamer Nanoparticles in an In Vivo Animal Model

This study aimed to examine the impact of different surface properties of poly(lactic-co-glycolic) acid (PLGA) nanoparticles (P NPs) and PLGA-Poloxamer nanoparticles (PP NPs) on their in vivo biodistribution. For this purpose, NPs were formulated via nanoprecipitation and loaded with diphenylhexatriene (DPH), a fluorescent dye. The obtained NPs underwent comprehensive characterization, encompassing their morphology, technological attributes, DPH release rate, and thermodynamic properties. The produced NPs were then administered to wild-type mice via intraperitoneal injection, and, at scheduled time intervals, the animals were euthanized. Blood samples, as well as the liver, lungs, and kidneys, were extracted for histological examination and biodistribution analysis. The findings of this investigation revealed that the presence of poloxamers led to smaller NP sizes and induced partial crystallinity in the NPs. The biodistribution and histological results from in vivo experiments evidenced that both, P and PP NPs, exhibited comparable concentrations in the bloodstream, while P NPs could not be detected in the other organs examined. Conversely, PP NPs were primarily sequestered by the lungs and, to a lesser extent, by the kidneys. Future research endeavors will focus on investigating the behavior of drug-loaded NPs in pathological animal models.

Monodisperse Sub-100 nm Au Nanoshells for Low-Fluence Deep-Tissue Photoacoustic Imaging

Nanoparticles with high absorption cross sections will advance therapeutic and bioimaging nanomedicine technologies. While Au nanoshells have shown great promise in nanomedicine, state-of-the-art synthesis methods result in scattering-dominant particles, mitigating their efficacy in absorption-based techniques that leverage the photothermal effect, such as photoacoustic (PA) imaging. We introduce a highly reproducible synthesis route to monodisperse sub-100 nm Au nanoshells with an absorption-dominant optical response. Au nanoshells with 48 nm SiO2 cores and 7 nm Au shells show a 14-fold increase in their volumetric absorption coefficient compared to commercial Au nanoshells with dimensions commonly used in nanomedicine. PA imaging with Au nanoshell contrast agents showed a 50% improvement in imaging depth for sub-100 nm Au nanoshells compared with the smallest commercially available nanoshells in a turbid phantom. Furthermore, the high PA signal at low fluences, enabled by sub-100 nm nanoshells, will aid the deployment of low-cost, low-fluence light-emitting diodes for PA imaging.

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.

Co-administration of Transportan Peptide Enhances the Cellular Entry of Liposomes in the Bystander Manner Both In Vitro and In Vivo

Liposomes have been widely used as a drug delivery vector. One way to further improve its therapeutic efficacy is to increase the cell entry efficiency. Covalent conjugation with cell-penetrating peptides (CPPs) and other types of ligands has been the mainstream strategy to tackle this issue. Although efficient, it requires additional chemical modifications on liposomes, which is undesirable for clinical translation. Our previous study showed that the transportan (TP) peptide, an amphiphilic CPP, was able to increase the cellular uptake of co-administered, but not covalently coupled, metallic nanoparticles (NPs). Termed bystander uptake, this process represents a simpler method to increase the cell entry of NPs without chemical modifications. Here, we extended our efforts to liposomes. Our results showed that co-administration with the TP peptide improved the internalization of liposome into a variety of cell lines in vitro. This effect was also observed in primary cells, ex vivo tumor slices, and in vivo tumor tissues. On the other hand, this peptide-assisted liposome internalization did not apply to cationic CPPs, which were the main inducers for bystander uptake in previous studies. We also found that TP-assisted bystander uptake of liposome is receptor dependent, and its activity is more sensitive to the inhibitors of the macropinocytosis pathway, underlining the potential cell entry mechanism. Overall, our study provides a simple strategy based on TP co-administration to increase the cell entry of liposomes, which may open up new avenues to apply TP peptides in nanotherapeutics.

Potential of fluorescent nanoprobe in diagnosis and treatment of Alzheimer's disease

Alzheimer's disease (AD) is well known for its insidious nature, slow progression and high incidence as a neurodegenerative disease. In the past, diagnosis of AD mainly depended on analysis of a patient's cognitive ability and behavior. Without a unified standard for analysis methods, this is prone to produce incorrect diagnoses. Currently, definitive diagnosis mainly relies on histopathological examination. Because of the advantages of precision, noninvasiveness, low toxicity and high spatiotemporal resolution, fluorescent nanoprobes are suitable for the early diagnosis of AD. This review summarizes the research progress of different kinds of fluorescent nanoprobes for AD diagnosis and therapy in recent years and provides an outlook on the development prospects of fluorescent nanoprobes.

The Potential of Curcumin-Capped Nanoparticle Synthesis in Cancer Therapy: A Green Synthesis Approach

Cancer nanotherapeutics is an important field of research which utilizes nanomaterials as an approach to cancer therapy. Nano-mediated therapeutic delivery systems overcome the adverse side effects of traditional cancer treatment methods. Nanoparticles (NPs) are considered excellent tumor-targeting vehicles due to their compact and variable size, large surface area, ability to load several genes and drugs, and mediation of increased therapeutic payload uptake. Despite the rapid development of nanotechnology, there is growing concern regarding the possible long-term side effects of NPs on the environment and human health. Green chemistry using plant materials, such as curcumin, is a sustainable alternative to conventional reduction methods and confers dual reducing and capping properties. Curcumin is a bioactive compound isolated from the rhizome of the Curcuma longa plant, which exhibits various medicinal properties. Curcumin-capped NPs exhibit increased solubility, bioavailability, therapeutic indices, and antitumor properties. This review highlights the potential and antitumor properties of economical, simple, and eco-friendly curcumin-synthesized and capped NPs for the localized delivery of therapeutic genes and drugs to the cancer tumor microenvironment with fewer adverse side effects.

β-Glucan-Functionalized Nanoparticles Down-Modulate the Proinflammatory Response of Mononuclear Phagocytes Challenged with Candida albicans

Systemic fungal infections are associated with significant morbidity and mortality, and Candida albicans is the most common causative agent. Recognition of yeast cells by immune cell surface receptors can trigger phagocytosis of fungal pathogens and a pro-inflammatory response that may contribute to fungal elimination. Nevertheless, the elicited inflammatory response may be deleterious to the host by causing excessive tissue damage. We developed a nanoparticle-based approach to modulate the host deleterious inflammatory consequences of fungal infection by using β1,3-glucan-functionalized polystyrene (β-Glc-PS) nanoparticles. β-Glc-PS nanoparticles decreased the levels of the proinflammatory cytokines TNF-α, IL-6, IL-1β and IL-12p40 detected in in vitro culture supernatants of bone marrow-derived dendritic cells and macrophage challenged with C. albicans cells. Moreover, β-Glc-PS nanoparticles impaired the production of reactive oxygen species by bone marrow-derived dendritic cells incubated with C. albicans. This immunomodulatory effect was dependent on the nanoparticle size. Overall, β-Glc-PS nanoparticles reduced the proinflammatory response elicited by fungal cells in mononuclear phagocytes, setting the basis for a targeted therapy aimed at protecting the host by lowering the inflammatory cost of infection.

Ultrasmall-in-Nano: Why Size Matters

Gold nanoparticles (AuNPs) are continuing to gain popularity in the field of nanotechnology. New methods are continuously being developed to tune the particles' physicochemical properties, resulting in control over their biological fate and applicability to in vivo diagnostics and therapy. This review focuses on the effects of varying particle size on optical properties, opsonization, cellular internalization, renal clearance, biodistribution, tumor accumulation, and toxicity. We review the common methods of synthesizing ultrasmall AuNPs, as well as the emerging constructs termed ultrasmall-in-nano-an approach which promises to provide the desirable properties from both ends of the AuNP size range. We review the various applications and outcomes of ultrasmall-in-nano constructs in vitro and in vivo.

Current Status and Challenges of Analytical Methods for Evaluation of Size and Surface Modification of Nanoparticle-Based Drug Formulations

The present review discusses the current status and difficulties of the analytical methods used to evaluate size and surface modifications of nanoparticle-based pharmaceutical products (NPs) such as liposomal drugs and new SARS-CoV-2 vaccines. We identified the challenges in the development of methods for (1) measurement of a wide range of solid-state NPs, (2) evaluation of the sizes of polydisperse NPs, and (3) measurement of non-spherical NPs. Although a few methods have been established to analyze surface modifications of NPs, the feasibility of their application to NPs is unknown. The present review also examined the trends in standardization required to validate the size and surface measurements of NPs. It was determined that there is a lack of available reference materials and it is difficult to select appropriate ones for modified NP surface characterization. Research and development are in progress on innovative surface-modified NP-based cancer and gene therapies targeting cells, tissues, and organs. Next-generation nanomedicine should compile studies on the practice and standardization of the measurement methods for NPs to design surface modifications and ensure the quality of NPs.

Food-Grade Titanium Dioxide Induces Toxicity in the Nematode Caenorhabditis elegans and Acute Hepatic and Pulmonary Responses in Mice

Food-grade titanium dioxide (E171) contains variable percentages of titanium dioxide (TiO2) nanoparticles (NPs), posing concerns for its potential effects on human and animal health. Despite many studies, the actual relationship between the physicochemical properties of E171 NPs and their interaction with biological targets is still far from clear. We evaluated the impact of acute E171 administration on invertebrate and vertebrate animals. In the nematode, Caenorhabditis elegans, the administration of up to 1.0 mg/mL of E171 did not affect the worm's viability and lifespan, but significantly impaired its pharyngeal function, reproduction, and development. We also investigated whether the intravenous administration of E171 in mice (at the dose of 6 mg/kg/body weight) could result in an acute over-absorption of filter organs. A significant increase of hepatic titanium concentration and the formation of microgranulomas were observed. Interstitial inflammation and parenchymal modification were found in the lungs, coupled with titanium accumulation. This was probably due to the propensity of TiO2 NPs to agglomerate, as demonstrated by transmission electron microscopy experiments showing that the incubation of E171 with serum promoted the formation of compact clusters. Overall, these data emphasize the actual risk for human and animal exposure to E171.

Heptamethine Cyanine-Loaded Nanomaterials for Cancer Immuno-Photothermal/Photodynamic Therapy: A Review

The development of strategies capable of eliminating metastasized cancer cells and preventing tumor recurrence is an exciting and extremely important area of research. In this regard, therapeutic approaches that explore the synergies between nanomaterial-mediated phototherapies and immunostimulants/immune checkpoint inhibitors have been yielding remarkable results in pre-clinical cancer models. These nanomaterials can accumulate in tumors and trigger, after irradiation of the primary tumor with near infrared light, a localized temperature increase and/or reactive oxygen species. These effects caused damage in cancer cells at the primary site and can also (i) relieve tumor hypoxia, (ii) release tumor-associated antigens and danger-associated molecular patterns, and (iii) induced a pro-inflammatory response. Such events will then synergize with the activity of immunostimulants and immune checkpoint inhibitors, paving the way for strong T cell responses against metastasized cancer cells and the creation of immune memory. Among the different nanomaterials aimed for cancer immuno-phototherapy, those incorporating near infrared-absorbing heptamethine cyanines (Indocyanine Green, IR775, IR780, IR797, IR820) have been showing promising results due to their multifunctionality, safety, and straightforward formulation. In this review, combined approaches based on phototherapies mediated by heptamethine cyanine-loaded nanomaterials and immunostimulants/immune checkpoint inhibitor actions are analyzed, focusing on their ability to modulate the action of the different immune system cells, eliminate metastasized cancer cells, and prevent tumor recurrence.

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

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

From Raman to SESORRS: moving deeper into cancer detection and treatment monitoring

Raman spectroscopy is a non-invasive technique that allows specific chemical information to be obtained from various types of sample. The detailed molecular information that is present in Raman spectra permits monitoring of biochemical changes that occur in diseases, such as cancer, and can be used for the early detection and diagnosis of the disease, for monitoring treatment, and to distinguish between cancerous and non-cancerous biological samples. Several techniques have been developed to enhance the capabilities of Raman spectroscopy by improving detection sensitivity, reducing imaging times and increasing the potential applicability for in vivo analysis. The different Raman techniques each have their own advantages that can accommodate the alternative detection formats, allowing the techniques to be applied in several ways for the detection and diagnosis of cancer. This feature article discusses the various forms of Raman spectroscopy, how they have been applied for cancer detection, and the adaptation of the techniques towards their use for in vivo cancer detection and in clinical diagnostics. Despite the advances in Raman spectroscopy, the clinical application of the technique is still limited and certain challenges must be overcome to enable clinical translation. We provide an outlook on the future of the techniques in this area and what we believe is required to allow the potential of Raman spectroscopy to be achieved for clinical cancer diagnostics.

Contrast-enhanced proton radiographic sensitivity limits for tumor detection

Purpose: Proton radiography may guide proton therapy cancer treatments with beam's-eye-view anatomical images and a proton-based estimation of proton stopping power. However, without contrast enhancement, proton radiography will not be able to distinguish tumor from tissue. To provide this contrast, functionalized, high- Z nanoparticles that specifically target a tumor could be injected into a patient before imaging. We conducted this study to understand the ability of gold, as a high- Z , biologically compatible tracer, to differentiate tumors from surrounding tissue. Approach: Acrylic and gold phantoms simulate a tumor tagged with gold nanoparticles (AuNPs). Calculations correlate a given thickness of gold to levels of tumor AuNP uptake reported in the literature. An identity, × 3 , and × 7 proton magnifying lens acquired lens-refocused proton radiographs at the 800-MeV LANSCE proton beam. The effects of gold in the phantoms, in terms of percent density change, were observed as changes in measured transmission. Variable areal densities of acrylic modeled the thickness of the human body. Results: A 1 - μ m -thick gold strip was discernible within 1 cm of acrylic, an areal density change of 0.2%. Behind 20 cm of acrylic, a 40 - μ m gold strip was visible. A 1-cm-diameter tumor tagged with 1 × 10 5 50-nm AuNPs per cell has an amount of contrast agent embedded within it that is equivalent to a 65 - μ m thickness of gold, an areal density change of 0.63% in a tissue thickness of 20 cm, which is expected to be visible in a typical proton radiograph. Conclusions: We indicate that AuNP-enhanced proton radiography might be a feasible technology to provide image-guidance to proton therapy, potentially reducing off-target effects and sparing nearby tissue. These data can be used to develop treatment plans and clinical applications can be derived from the simulations.

Coating an adenovirus with functionalized gold nanoparticles favors uptake, intracellular trafficking and anti-cancer therapeutic efficacy

Adenoviral (Ad) vectors have proven to be important tools for gene and cell therapy, although some issues still need to be addressed, such as undesired interactions with blood components and off-target sequestration that ultimately hamper efficacy. In the past years, several organic and inorganic materials have been developed to reduce immunogenicity and improve biodistribution of Ad vectors. Here we investigated the influence of the functionalization of 14 nm PEGylated gold nanoparticles (AuNPs) with quaternary ammonium groups and an arginine-glycine-aspartic acid (RGD)-motif on the uptake and biodistribution of Ad vectors. We report the formation of Ad@AuNPs complexes that promote cell attachment and uptake, independently of the presence of the coxsackievirus and adenovirus receptor (CAR) and α_vβ₃ and α_vβ₅ integrins, significantly improving transduction without limiting Ad bioactivity. Besides, the presence of the RGD peptide favors tumor targeting and decreases Ad sequestration in the liver. Additionally, tumor delivery of a coated Ad vector expressing the human sodium iodide symporter (hNIS) by mesenchymal stem cells induces increased accumulation of radioactive iodine (¹³¹I) and tumor volume reduction compared to naked Ad-hNIS, highlighting the promising potential of our coating formulation in cancer gene therapy. STATEMENT OF SIGNIFICANCE: Modification of adenoviral vectors with lipids and polymers can reduce interactions with blood components and increase tumor accumulation; however, increased toxicity and reduced transduction efficiency were indicated. Coating with gold nanoparticles has proven to be a successful strategy for increasing the efficiency of transduction of receptor-defective cell lines. Here we explore the contribution of cell surface receptors on the mechanisms of entry of Ad vectors coated with gold nanoparticles in cell lines with varying degrees of resistance to infection. The enhancement of the anti-tumoral effect shown in this work provides new evidence for the potential of our formulation.

Development of theranostic dual-layered Au-liposome for effective tumor targeting and photothermal therapy

BACKGROUND

Photothermal therapy (PTT) is an emerging anti-cancer therapeutic strategy that generates hyperthermia to ablate cancer cells under laser irradiation. Gold (Au) coated liposome (AL) was reported as an effective PTT agent with good biocompatibility and excretory property. However, exposed Au components on liposomes can cause instability in vivo and difficulty in further functionalization.

RESULTS

Herein, we developed a theranostic dual-layered nanomaterial by adding liposomal layer to AL (LAL), followed by attaching polyethylene glycol (PEG) and radiolabeling. Functionalization with PEG improves the in vivo stability of LAL, and radioisotope labeling enables in vivo imaging of LAL. Functionalized LAL is stable in physiological conditions, and ⁶⁴Cu labeled LAL (⁶⁴Cu-LAL) shows a sufficient blood circulation property and an effective tumor targeting ability of 16.4%ID g^-1 from in vivo positron emission tomography (PET) imaging. Also, intravenously injected LAL shows higher tumor targeting, temperature elevation in vivo, and better PTT effect in orthotopic breast cancer mouse model compared to AL. The tumor growth inhibition rate of LAL was 3.9-fold higher than AL.

CONCLUSION

Based on these high stability, in vivo imaging ability, and tumor targeting efficiency, LAL could be a promising theranostic PTT agent.

Development of Bio-Functionalized, Raman Responsive, and Potentially Excretable Gold Nanoclusters

Gold nanoparticles (AuNPs) are used experimentally for non-invasive in vivo Raman monitoring because they show a strong absorbance in the phototherapeutic window (650–850 nm), a feature that is accompanied by a particle size in excess of 100 nm. However, these AuNPs cannot be used clinically because they are likely to persist in mammalian systems and resist excretion. In this work, clustered ultrasmall (sub-5 nm) AuNP constructs for in vivo Raman diagnostic monitoring, which are also suitable for mammalian excretion, were synthesized and characterized. Sub-5 nm octadecyl amine (ODA)-coated AuNPs were clustered using a labile dithiol linker: ethylene glycol bis-mercaptoacetate (EGBMA). Upon clustering via a controlled reaction and finally coating with a polymeric amphiphile, a strong absorbance in the phototherapeutic window was demonstrated, thus showing the potential suitability of the construct for non-invasive in vivo detection and monitoring. The clusters, when labelled with a biphenyl-4-thiol (BPT) Raman tag, were shown to elicit a specific Raman response in plasma and to disaggregate back to sub-5 nm particles under physiological conditions (37 °C, 0.8 mM glutathione, pH 7.4). These data demonstrate the potential of these new AuNP clusters (Raman NanoTheranostics—RaNT) for in vivo applications while being in the excretable size window.

A Review on the Development of Gold and Silver Nanoparticles-Based Biosensor as a Detection Strategy of Emerging and Pathogenic RNA Virus

The emergence of highly pathogenic and deadly human coronaviruses, namely SARS-CoV and MERS-CoV within the past two decades and currently SARS-CoV-2, have resulted in millions of human death across the world. In addition, other human viral diseases, such as mosquito borne-viral diseases and blood-borne viruses, also contribute to a higher risk of death in severe cases. To date, there is no specific drug or medicine available to cure these human viral diseases. Therefore, the early and rapid detection without compromising the test accuracy is required in order to provide a suitable treatment for the containment of the diseases. Recently, nanomaterials-based biosensors have attracted enormous interest due to their biological activities and unique sensing properties, which enable the detection of analytes such as nucleic acid (DNA or RNA), aptamers, and proteins in clinical samples. In addition, the advances of nanotechnologies also enable the development of miniaturized detection systems for point-of-care (POC) biosensors, which could be a new strategy for detecting human viral diseases. The detection of virus-specific genes by using single-stranded DNA (ssDNA) probes has become a particular interest due to their higher sensitivity and specificity compared to immunological methods based on antibody or antigen for early diagnosis of viral infection. Hence, this review has been developed to provide an overview of the current development of nanoparticles-based biosensors that target pathogenic RNA viruses, toward a robust and effective detection strategy of the existing or newly emerging human viral diseases such as SARS-CoV-2. This review emphasizes the nanoparticles-based biosensors developed using noble metals such as gold (Au) and silver (Ag) by virtue of their powerful characteristics as a signal amplifier or enhancer in the detection of nucleic acid. In addition, this review provides a broad knowledge with respect to several analytical methods involved in the development of nanoparticles-based biosensors for the detection of viral nucleic acid using both optical and electrochemical techniques.

Subcellular imaging and diagnosis of cancer using engineered nanoparticles

The advances in the synthesis of nanoparticles with engineered properties are reported to have profound applications in oncological disease detection via optical and multimodal imaging and therapy. Among various nanoparticle-assisted imaging techniques, engineered fluorescent nanoparticles show great promise from high contrast images and localized therapeutic applications. Of all the fluorescent nanoparticles available, the gold nanoparticles, carbon dots, and upconversion nanoparticles are emerging recently as the most promising candidates for diagnosis, treatment, and cancer monitoring. This review addresses the recent progress in engineering the properties of these emerging nanoparticles and their application for cancer diagnosis and therapy. In addition, the potential of these particles for subcellular imaging is also reviewed here.

Development of FL/MR dual-modal Au nanobipyramids for targeted cancer imaging and photothermal therapy

Multifunctional nanodrugs have emerged as an effective platform to integrate multiple imaging and therapeutic functions for tremendous biomedical applications. However, the development of a simple potent theranostic nanoplatform is still an intractable challenge. Herein, a novel theranostic nanoplatform was developed by coupling prepared Au nanobipyramids with Gd₂O₃, Au nanoclusters and denatured bovine serum albumin (AuNBP-Gd₂O₃/Au-dBSA) for FL/MR dual-modal imaging guided photothermal therapy. AS1411 aptamers were conjugated to enhance its targetability towards breast cancer. The AS1411-AuNBP-Gd₂O₃/Au-dBSA suspension could be readily heated above 40 °C at a low concentration (2 mg/L) and NIR density (1 W/cm²). The AS1411-AuNBP-Gd₂O₃/Au-dBSA revealed a fluorescence quantum yield of 4.2% and higher longitudinal relaxivity rate of 6.75 mM^-1 s^-1 compared to Gd-DTPA of 4.45 mM^-1 s^-1. As a result, the AS1411-AuNBP-Gd₂O₃/Au-dBSA functions as a multimodal nanoprobe of photothermal, fluorescence and MR imaging for specific tumor diagnosis and guidance of therapy, which was validated via in vitro and in vivo tests. Moreover, AS1411-AuNBP-Gd₂O₃/Au-dBSA nanoparticles indicated excellent photothermal anticancer effect more than 95% in both in vitro and in vivo tests. Besides, the low toxicity of AS1411-AuNBP-Gd₂O₃/Au-dBSA nanocomposites was further confirmed in vitro and in vivo. Thus, these results demonstrated the AS1411-AuNBP-Gd₂O₃/Au-dBSA nanocomposites as a rational design of multifunctional nanoplatform to enable multimodal imaging guided photothermal therapy.

Improving kidney targeting: The influence of nanoparticle physicochemical properties on kidney interactions

Kidney-targeted nanoparticles have become of recent interest due to their potential to deliver drugs directly to diseased tissue, decrease off-target adverse effects, and increase overall tolerability to patients with chronic kidney disease that require lifelong drug exposure. Given the physicochemical properties of nanoparticles can drastically affect their ability to extravasate past cellular and biological barriers and access the kidneys, we surveyed the literature from the past decade and analyzed how nanoparticle size, charge, shape, and material density affects passage and interaction with the kidneys. Specifically, we found that nanoparticle size impacted the mechanism of nanoparticle entry into the kidneys such as glomerular filtration or tubular secretion. In addition, we found charge, aspect ratio, and material density influences nanoparticle renal retention and provide insights for designing nanoparticles for passive kidney targeting. Finally, we conclude by highlighting active targeting strategies that bolster kidney retention and discuss the clinical status of nanomedicine for kidney diseases.

Effects of Surface Protein Adsorption on the Distribution and Retention of Intratumorally Administered Gold Nanoparticles

The heterogeneous distribution of delivery or treatment modalities within the tumor mass is a crucial limiting factor for a vast range of theranostic applications. Understanding the interactions between a nanomaterial and the tumor microenvironment will help to overcome challenges associated with tumor heterogeneity, as well as the clinical translation of nanotheranostic materials. This study aims to evaluate the influence of protein surface adsorption on gold nanoparticle (GNP) biodistribution using high-resolution computed tomography (CT) preclinical imaging in C57BL/6 mice harboring Lewis lung carcinoma (LLC) tumors. LLC provides a valuable model for study due to its highly heterogenous nature, which makes drug delivery to the tumor challenging. By controlling the adsorption of proteins on the GNP surface, we hypothesize that we can influence the intratumoral distribution pattern and particle retention. We performed an in vitro study to evaluate the uptake of GNPs by LLC cells and an in vivo study to assess and quantify the GNP biodistribution by injecting concentrated GNPs citrate-stabilized or passivated with bovine serum albumin (BSA) intratumorally into LLC solid tumors. Quantitative CT and inductively coupled plasma optical emission spectrometry (ICP-OES) results both confirm the presence of particles in the tumor 9 days post-injection (n = 8 mice/group). A significant difference is highlighted between citrate-GNP and BSA-GNP groups (** p < 0.005, Tukey's multiple comparisons test), confirming that the protein corona of GNPs modifies intratumoral distribution and retention of the particles. In conclusion, our investigations show that the surface passivation of GNPs influences the mechanism of cellular uptake and intratumoral distribution in vivo, highlighting the spatial heterogeneity of the solid tumor.

Recent Advances in Nanotechnology for the Treatment of Melanoma

Melanoma is one of the most aggressive forms of skin cancer, with few possibilities for therapeutic approaches, due to its multi-drug resistance and, consequently, low survival rate for patients. Conventional therapies for treatment melanoma include radiotherapy, chemotherapy, targeted therapy, and immunotherapy, which have various side effects. For this reason, in recent years, pharmaceutical and biomedical research has focused on new sito-specific alternative therapeutic strategies. In this regard, nanotechnology offers numerous benefits which could improve the life expectancy of melanoma patients with very low adverse effects. This review aims to examine the latest advances in nanotechnology as an innovative strategy for treating melanoma. In particular, the use of different types of nanoparticles, such as vesicles, polymers, metal-based, carbon nanotubes, dendrimers, solid lipid, microneedles, and their combination with immunotherapies and vaccines will be discussed.

Alternating stealth polymer coatings between administrations minimizes toxic and antibody immune responses towards nanomedicine treatment regimens

In efforts to achieve minimal systemic toxicity and high tumor delivery efficiencies in cancer therapy, various nanomedicine formulations having stealth polymer coatings have been developed for minimizing immune cell uptake and off-target macrophage phagocyte system (MPS) organ accumulation. Despite an initial reduction in immune cell uptake, stealth nanoparticles still initiate an antibody immune response. This response acts on subsequent administrations in treatment regimens resulting in accelerated blood clearance of particles into MPS organs, particularly the liver, where they are retained for prolonged periods. Consequently, doses after the first administration in treatment regimens have diminished tumor accumulation and increased MPS toxicity. Here, we present a strategy reducing antibody responses to each dose in a treatment regimen by alternating between polyethylene-glycol and polymethyloxazoline polymers as the nanoparticle coating between administrations. In a weekly dosing regimen, we find that the first dose of particles having either coating display similar favorable pharmacokinetics and biodistributions, thus allowing the polymers to be used interchangeably. However, when maintaining the same coating in subsequent administrations, we find that particles are in circulation at the height of the antibody immune response resulting in 50-60% decreases of circulation half-lives and tumor accumulation along with 50% increases in liver accumulation. By alternating the polymers used in the nanoparticle coating between administrations, we find each dose maintains favorable in vivo behaviors at the height of the antibody immune response to the previous administration. Furthermore, our strategy increases the clearance of particles uptaken by macrophages and hepatocytes, resulting in marked decreases in hepatotoxicity.

Macropinocytosis as a cell entry route for peptide-functionalized and bystander nanoparticles

Endocytic pathways provide the primary route for therapeutic and diagnostic nanoparticles (NPs) to enter cells and subcellular compartments. A better understanding of these cell entry processes will not only aid in nanomaterial applications but also broaden our knowledge of cell biology. Among the endocytic routes, macropinocytosis has unique characteristics for engulfing NPs and other large cargo, yet its molecular machinery and involvement in NP uptake are far less characterized relative to other pathways. In this review, we summarize the current knowledge on the macropinocytic machinery, and its involvement in NP internalization. Particularly, we differentiate ligand (specifically peptide)-functionalized and unfunctionalized NPs (bystander NPs). While most of previous research focused on ligand-functionalized NPs, we showcase here a synergistic effect between these two NP types during their cell entry through receptor-mediated macropinocytosis. The regulation of NP uptake efficiency by extracellular amino acids is also highlighted in the context of interconnections between macropinocytosis and metabolic signaling. These discussions may fuel future research interests in improving NP internalization through this pathway, and open a new avenue to study the interplay among endocytosis, metabolism and nanomedicine.

Advances in Magnetic Nanoparticle-Mediated Cancer Immune-Theranostics

Cancer immunotherapy is a cutting-edge strategy that eliminates cancer cells by amplifying the host's immune system. However, the low response rate and risks of inducing systemic toxicity have raised uncertainty in the treatment. Magnetic nanoparticles (MNPs) as a versatile theranostic tool can be used to target delivery of multiple immunotherapeutics and monitor cell/tissue responses. These capabilities enable the real-time characterization of the factors that contribute to immunoactivity so that future treatments can be optimized. The magnetic properties of MNPs further allow the implementation of magnetic navigation and magnetic hyperthermia for boosting the efficacy of immunotherapy. The multimodal approach opens an avenue to induce robust immune responses, minimize safety issues, and monitor immune activities simultaneously. Thus, the object of this review is to provide an overview of the burgeoning fields and to highlight novel technologies for next-generation immunotherapy. The review further correlates the properties of MNPs with the latest treatment strategies to explore the crosstalk between magnetic nanomaterials and the immune system. This comprehensive review of MNP-derived immunotherapy covers the obstacles and opportunities for future development and clinical translation.

Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy

The rapid development of nanotechnology offers a variety of potential therapeutic strategies for cancer treatment. High atomic element nanomaterials are often utilized as radiosensitizers due to their unique photoelectric decay characteristics. Among them, gold nanoparticles (GNPs) are one of the most widely investigated and are considered to be an ideal radiosensitizers for radiotherapy due to their high X-ray absorption and unique physicochemical properties. Over the last few decades, multi-disciplinary studies have focused on the design and optimization of GNPs to achieve greater dosing capability and higher therapeutic effects and highlight potential mechanisms for radiosensitization of GNPs. Although the radiosensitizing potential of GNPs has been widely recognized, its clinical translation still faces many challenges. This review analyses the different roles of GNPs as radiosensitizers in cancer radiotherapy and summarizes recent advances. In addition, the underlying mechanisms of GNP radiosensitization, including physical, chemical and biological mechanisms are discussed, which may provide new directions for the optimization and clinical transformation of next-generation GNPs.

Assessment of Polyethylene Glycol-Coated Gold Nanoparticle Toxicity and Inflammation In Vivo Using NF-κB Reporter Mice

Polyethylene glycol (PEG) coating of gold nanoparticles (AuNPs) improves AuNP distribution via blood circulation. The use of PEG-coated AuNPs was shown to result in acute injuries to the liver, kidney, and spleen, but long-term toxicity has not been well studied. In this study, we investigated reporter induction for up to 90 days in NF-κB transgenic reporter mice following intravenous injection of PEG-coated AuNPs. The results of different doses (1 and 4 μg AuNPs per gram of body weight), particle sizes (13 nm and 30 nm), and PEG surfaces (methoxyl- or carboxymethyl-PEG 5 kDa) were compared. The data showed up to 7-fold NF-κB reporter induction in mouse liver from 3 h to 7 d post PEG-AuNP injection compared to saline-injected control mice, and gradual reduction to a level similar to control by 90 days. Agglomerates of PEG-AuNPs were detected in liver Kupffer cells, but neither gross pathological abnormality in liver sections nor increased activity of liver enzymes were found at 90 days. Injection of PEG-AuNPs led to an increase in collagen in liver sections and elevated total serum cholesterol, although still within the normal range, suggesting that inflammation resulted in mild fibrosis and affected hepatic function. Administrating PEG-AuNPs inevitably results in nanoparticles entrapped in the liver; thus, further investigation is required to fully assess the long-term impacts by PEG-AuNPs on liver health.

Beyond gold nanoparticles cytotoxicity: Potential to impair metastasis hallmarks

Gold nanoparticle (AuNP)-based systems have been extensively investigated as diagnostic and therapeutic agents due to their tunable properties and easy surface functionalization. Upon cell uptake, AuNPs present an inherent cell impairment potential based on organelle and macromolecules damage, leading to cell death. Such cytotoxicity is concentration-dependent and completely undesirable, especially if unspecific. However, under non-cytotoxic concentrations, internalized AuNPs could potentially weaken cells and act as antitumor agents. Therefore, this study aimed to investigate the antitumor effect of ultrasmall AuNPs (~3 nm) stabilized by the anionic polysaccharide gum arabic (GA-AuNPs). Other than intrinsic cytotoxicity, the focus was downregulation of cancer hallmarks of aggressive tumors, using a highly metastatic model of melanoma. We first demonstrated that GA-AuNPs showed excellent stability under biological environment. Non-cytotoxic concentrations to seven different cell lines, including tumorigenic and non-tumorigenic cells, were determined by standard 2D in vitro assays. Gold concentrations ≤ 2.4 mg L^-1 (16.5 nM AuNPs) were non-cytotoxic and therefore chosen for further analyses. Cells exposed to GA-AuNPs were uptaken by melanoma cells through endocytic processes. Next we described remarkable biological properties using non-cytotoxic concentrations of this nanomaterial. Invasion through an extracellular matrix barrier as well as 3D growth capacity (anchorage-independent colony formation and spheroids growth) were negatively affected by 2.4 mg L^-1 GA-AuNPs. Additionally, exposed spheroids showed morphological changes, suggesting that GA-AuNPs could penetrate into the preformed tumor and affect its integrity. All together these results demonstrate that side effects, such as cytotoxicity, can be avoided by choosing the right concentration, nevertheless, preserving desirable effects such as modulation of key tumor cell malignancy features.

Addressing the challenges to increase the efficiency of translating nanomedicine formulations to patients

INTRODUCTION

Nanotechnology is in a growth phase for drug delivery and medical imaging. Nanomaterials with unique properties present opportunities for encapsulation of therapeutics and imaging agents, along with conjugation to ligands for targeting. Favorable chemistry of nanomaterials can create formulations that address critical challenges for therapeutics, such as insolubility and a low capacity to cross the blood-brain-barrier (BBB) and intestinal wall.

AREAS COVERED

The authors investigate challenges faced during translation of nanomedicines while suggesting reasons as to why some nanoformulations have under-performed in clinical trials. They assess physiological barriers such as the BBB and gut mucus that nanomedicines must overcome to deliver cargos. They also provide an overview with examples of how nanomedicines can be designed to improve localization and site-specific delivery (e.g., encapsulation, bioconjugation, and triggered-release).

EXPERT OPINION

There are examples where nanomedicines have demonstrated improved efficacy of payload in humans; however, most of the advantages conferred were in improved pharmacokinetics and reduced toxicity. Problematic data show susceptibility of nanoformulations against natural protective mechanisms present in the body, including distribution impediment by physiological barriers and activation of the reticuloendothelial system. Further initiatives should address current challenges while expanding the scope of nanomedicine into advanced biomedical imaging and antibiotic delivery.

Chitosan-Based Non-viral Gene and Drug Delivery Systems for Brain Cancer

Central nervous system (CNS) tumors are a leading source of morbidity and mortality worldwide. Today, different strategies have been developed to allow targeted and controlled drug delivery into the brain. Gene therapy is a system based on the modification of patient's cells through the introduction of genetic material to exert a specific action. Administration of the foreign genetic material can be done through viral-mediated delivery or non-viral delivery via physical or mechanical systems. For brain cancer specifically, gene therapy can overcome the actual challenge of blood brain barrier penetration, the main reason for therapeutic failure. Chitosan (CS), a natural based biodegradable polymer obtained from the exoskeleton of crustaceans such as crab, shrimp, and lobster, has been used as a delivery vehicle in several non-viral modification strategies. This cationic polysaccharide is highly suitable for gene delivery mainly due to its chemical properties, its non-toxic nature, its capacity to protect nucleic acids through the formation of complexes with the genetic material, and its ease of degradation in organic environments. Recent evidence supports the use of CS as an alternative gene delivery system for cancer treatment. This review will describe multiple studies highlighting the advantages and challenges of CS-based delivery structures for the treatment of brain tumors. Furthermore, this review will provide insight on the translational potential of various CS based-strategies in current clinical cancer studies. Specifically, CS-based nanostructures including nanocapsules, nanospheres, solid-gel formulations, and nanoemulsions, also microshperes and micelles will be evaluated.

The Interactions of Quantum Dot-Labeled Silk Fibroin Micro/Nanoparticles with Cells

When silk fibroin particles are used for controlled drug delivery, particle size plays a key role in the location of the carrier on the cells as well as the transport pathway, utilization efficiency, and therapeutic effect of the drugs. In this study, the interactions of different-sized silk fibroin particles and cell lines were investigated. Silk fibroin microparticles with dry size of 1.9 ± 0.4 μm (2.7 ± 0.3 μm in wet state) and silk fibroin nanoparticles with dry size of 51.5 ± 11.0 nm (174.8 ± 12.5 nm in wet state) were prepared by salting-out method and high-voltage electrospray method, respectively. CdSe/ZnS quantum dots were coupled to the surface of the micro/nanoparticles. Photostability observations indicated that the fluorescence stability of the quantum dots was much higher than that of fluorescein isothiocyanate. In vitro, microparticles and nanoparticles were co-cultured with human umbilical vein endothelial cells EA.hy 926 and cervical cancer cells HeLa, respectively. The fluorescence test and cell viability showed that the EA.hy926 cells tended to be adhered to the microparticle surfaces and the cell proliferation was significantly promoted, while the nanoparticles were more likely to be internalized in HeLa cells and the cell proliferation was notably inhibited. Our findings might provide useful information concerning effective drug delivery that microparticles may be preferred if the drugs need to be delivered to normal cell surface, while nanoparticles may be preferred if the drugs need to be transmitted in tumor cells.

Shear Stress-Dependent Targeting Efficiency Using Self-Assembled Gelatin-Oleic Nanoparticles in a Biomimetic Microfluidic System

Cellular properties and microenvironments, as well as the characteristics of nanoparticles (NPs), affect the cellular uptake and cytotoxic effects of drug-loaded NPs. Since there is fluid flow in the human blood system, fluid flow also affects the drug delivery efficiency of NPs. This study aimed to evaluate the cellular behaviors of drug-loaded soft NPs on A549 cancer cells under different levels of shear stress (0.5, 5, and 50 dynes/cm²) in the biomimetic microfluidic system. The soft self-assembled NPs were formed by the gelatin-oleic conjugate (GOC). The poorly water-soluble coumarin-6 or paclitaxel (PTX) were used as model markers for encapsulation within self-assembled NPs (C-GONs or PTX-GONs, respectively). The cellular uptake of C-GONs was found to be improved with shear-stress dependence. The inhibitory concentration (IC₅₀) of PTX-GONs at 0.5, 5, and 50 dynes/cm² was 0.106 µg/mL, 0.108 µg/mL, and 0.091 µg/mL, respectively, as compared to 0.138 µg/mL in a static condition. The cell killing efficiency of PTX-GONs was increased in the highest shear stress of 50 dynes/cm² in the static condition, and other levels of shear stress in dynamic conditions.

Influence of a shape of gold nanoparticles on the dose enhancement in the wide range of gold mass concentration for high-energy X-ray beams from a medical linac

Aim

This work is focused on the Monte Carlo microdosimetric calculations taking into account the influence of the AuNPs' shape, size and mass concentration on the radiation dose enhancement for the high-energy 6 MV and 18 MV X-ray therapeutic beams from a medical linac.

Background

Due to a high atomic number and the photoelectric effect, gold nanoparticles can significantly enhance doses of ionizing radiation. However, this enhancement depends upon several parameters, such as, inter alia, nanoparticles' shape etc.

Method

The simulated system was composed of the therapeutic beam, a water phantom with the target volume (with and without AuNPs) located at the depth of the maximum dose, i.e. at 1.5 cm for the 6 MV beam and at 3.5 cm for the 18 MV one. In the study the GEANT4 code was used because it makes it possible to get a very short step of simulation which is required in case of simulating the radiation interactions with nanostructures.

Results

The dependence between the dose increase and the mass concentration of gold was determined and described by a simple mathematical formula for three different shapes of gold nanoparticles - two nanorods of different sizes and a flat 2D structure. The dose increase with the saturation occurring with the increasing mass concentration of gold was observed.

Conclusions

It was found that relatively large cylindrical gold nanoparticles can limit the increase of the dose absorbed in the target volume much more than the large 2D gold nanostructure.

Nanosystems for Improved Targeted Therapies in Melanoma

Melanoma is one of the most aggressive forms of skin cancer, with limited therapeutic options. Since its incidence has been rapidly rising in recent years, the study of new targeted therapeutic strategies has increased. The implication of nanoscience in the development of alternative targeted therapies for melanoma has multiple benefits and could significantly improve the outcome of melanoma patients. In this paper, we review the most recent progress in the field of targeted therapies, emphasizing the impact of nanoscale materials on the targeting and controlled release of anti-tumor drugs. The applications of nanomedicine in the management of melanoma are extensive and refer to sentinel lymph node mapping, chemotherapy, and RNA interference; each of these applications harboring the potential to develop efficient and personalized diagnostic techniques and therapies. Further research, especially in clinical trials, is needed to establish whether fighting melanoma on the nanoscale level represents the key to reaching a critical inflection point in mankind’s battle with metastatic melanoma.

Probing the biological obstacles of nanomedicine with gold nanoparticles

Despite massive growth in nanomedicine research to date, the field still lacks fundamental understanding of how certain physical and chemical features of a nanoparticle affect its ability to overcome biological obstacles in vivo and reach its intended target. To gain fundamental understanding of how physical and chemical parameters affect the biological outcomes of administered nanoparticles, model systems that can systematically manipulate a single parameter with minimal influence on others are needed. Gold nanoparticles are particularly good model systems in this case as one can synthetically control the physical dimensions and surface chemistry of the particles independently and with great precision. Additionally, the chemical and physical properties of gold allow particles to be detected and quantified in tissues and cells with high sensitivity. Through systematic biological studies using gold nanoparticles, insights toward rationally designed nanomedicine for in vivo imaging and therapy can be obtained. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Gold Nanorods-Based Smart Nanoplatforms for Synergic Thermotherapy and Chemotherapy of Tumor Metastasis

The combination therapy of photothermal therapy and chemotherapy as a promising strategy has drawn extensive attention by overcoming the limitations of conventional treatments in tumor therapy. Gold nanorods-based nanoplatforms were herein designed by integrating doxorubicin (DOX)- and polydopamine-coated gold nanorods (GNRs@PDA) for tumor metastasis inhibition and multifunctional drug delivery. The GNRs@PDA-poly(ethylene glycol) (PEG)-DOX nanocomplex showed robust stability and excellent near-infrared (NIR) photothermal conversion efficiency under laser irradiation. The release of loaded DOX from GNRs@PDA-PEG-DOX nanocomposites was improved in tumor microenvironments. Furthermore, the PDA-functionalized GNR nanocomposites were expected to be potential photoacoustic imaging agents for imaging-guided tumor therapy. Upon NIR laser irradiation, the efficiency of tumor inhibition of GNRs@PDA-PEG-DOX is greater than that of the other group in vitro and in vivo, which was confirmed by immunohistochemistry staining, demonstrating a promising strategy for suppression of tumor metastasis and low long-term systemic toxicity. These results illustrated a promising strategy of tailor-made GNRs@PDA-PEG-DOX nanoplatforms for ablation of tumor and suppression of tumor metastasis in clinical application.

DM1 Loaded Ultrasmall Gold Nanoparticles Display Significant Efficacy and Improved Tolerability in Murine Models of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common cancer worldwide with poor prognosis and limited options for treatment. Life expectancy after diagnosis is short; the currently available treatments are not well tolerated and have limited clinical benefit. There is a clear unmet clinical need for the development of new treatments. In this study, ultrasmall, 2 nm gold core nanoparticles (MidaCore) conjugated with the potent maytansine analogue DM1 (MTC-100038) were assessed as a systemic nanomedicine for the treatment of hepatocellular carcinoma. The platform improved overall tolerability of DM1, permitting ∼3-fold higher levels of drug to be administered compared to free drug. Dose for dose, MTC-100038 also facilitated delivery of ∼2.0-fold higher ( p = 0.039) levels of DM1 to the tumor compared to free DM1. MTC-100038 produced significant efficacy (tumor growth index ∼102%; p = <0.0001), in several murine xenograft models of HCC, and was superior to both free DM1 and the current standard of care, sorafenib. Furthermore, MTC-100038 displayed potent (nM) in vitro activity in various HCC primary patient derived cell lines and across various other different cancer cell types. These data demonstrate the potential of MidaCore nanoparticles to enhance tumor delivery of cytotoxic drugs and indicate MTC-100038 is worthy of further investigation as a potential treatment for HCC and other cancer types.