Using Nanoparticles in Medicine for Liver Cancer Imaging

High-Molecular-Weight Fractions of Spruce and Eucalyptus Lignin as a Perspective Nanoparticle-Based Platform for a Therapy Delivery in Liver Cancer

The natural polymer, lignin, possesses unique biodegradable and biocompatible properties, making it highly attractive for the generation of nanoparticles for targeted cancer therapy. In this study, we investigated spruce and eucalyptus lignin nanoparticles (designated as S-and E-LNPs, respectively). Both LNP types were generated from high-molecular-weight (M_w) kraft lignin obtained as insoluble residues after a five-step solvent fractionation approach, which included ethyl acetate, ethanol, methanol, and acetone. The resulting S-and E-LNPs ranged in size from 16 to 60 nm with uniform spherical shape regardless of the type of lignin. The preparation of LNPs from an acetone-insoluble lignin fraction is attractive because of the use of high-M_w lignin that is otherwise not suitable for most polymeric applications, its potential scalability, and the consistent size of the LNPs, which was independent of increased lignin concentrations. Due to the potential of LNPs to serve as delivery platforms in liver cancer treatment, we tested, for the first time, the efficacy of newly generated E-LNPs and S-LNPs in two types of primary liver cancer, hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), in vitro. Both S-LNPs and E-LNPs inhibited the proliferation of HCC cells in a dose-dependent manner and did not affect CCA cell line growth. The inhibitory effect toward HCC was more pronounced in the E-LNP-treated group and was comparable to the standard therapy, sorafenib. Also, E-LNPs induced late apoptosis and necroptosis while inhibiting the HCC cell line. This study demonstrated that an elevated number of carbohydrates on the surface of the LNPs, as shown by NMR, seem to play an important role in mediating the interaction between LNPs and eukaryotic cells. The latter effect was most pronounced in E-LNPs. The novel S- and E-LNPs generated in this work are promising materials for biomedicine with advantageous properties such as small particle size and tailored surface functionality, making them an attractive and potentially biodegradable delivery tool for combination therapy in liver cancer, which still has to be verified in vivo using HCC and CCA models.

Recent advances in hepatocellular carcinoma therapeutic strategies and imaging-guided treatment

Hepatocellular carcinoma (HCC) is one of the most common malignant cancer in the world, which greatly threatens human health. However, the routine treatment strategies for HCC have failed to specifically eradicate the tumorigenic cells, leading to the occurrence of metastasis and recurrence. To improve treatment efficacies, the development of novel effective technologies is urgently required. Recently, nanotechnologies have gained the extensive attention in cancer targeted therapy, which could provide a promising way for HCC clinical practice. However, a successful cancer management depends on accurate diagnosis of the tumour along with precise therapeutic protocol, thereby predicting the tumour response to existing therapies. The synergistic effect of targeted therapeutic systems and imaging approaches (also called 'imaging-guided cancer treatment') may establish a more effective platform for individual cancer care. This review outlines the recent advanced nano-targeted and -traceable therapeutic strategies for HCC management. The multifunctional nano agents that have both diagnosis and therapy abilities are highlighted. Finally, we conclude with our perspectives on the future development and challenges of HCC nanotheranostics.

The Urokinase Receptor (uPAR) as a "Trojan Horse" in Targeted Cancer Therapy: Challenges and Opportunities

Simple Summary

Discovered more than three decades ago, the urokinase-type plasminogen activator receptor (uPAR) has now firmly established itself as a versatile molecular target holding promise for the treatment of aggressive malignancies. The copious abundance of uPAR in virtually all human cancerous tissues versus their healthy counterparts has fostered a gradual shift in the therapeutic landscape targeting this receptor from function inhibition to cytotoxic approaches to selectively eradicate the uPAR-expressing cells by delivering a targeted cytotoxic insult. Multiple avenues are being explored in a preclinical setting, including the more innovative immune- or stroma targeting therapies. This review discusses the current state of these strategies, their potentialities, and challenges, along with future directions in the field of uPAR targeting.

Abstract

One of the largest challenges to the implementation of precision oncology is identifying and validating selective tumor-driving targets to enhance the therapeutic efficacy while limiting off-target toxicity. In this context, the urokinase-type plasminogen activator receptor (uPAR) has progressively emerged as a promising therapeutic target in the management of aggressive malignancies. By focalizing the plasminogen activation cascade and subsequent extracellular proteolysis on the cell surface of migrating cells, uPAR endows malignant cells with a high proteolytic and migratory potential to dissolve the restraining extracellular matrix (ECM) barriers and metastasize to distant sites. uPAR is also assumed to choreograph multiple other neoplastic stages via a complex molecular interplay with distinct cancer-associated signaling pathways. Accordingly, high uPAR expression is observed in virtually all human cancers and is frequently associated with poor patient prognosis and survival. The promising therapeutic potential unveiled by the pleiotropic nature of this receptor has prompted the development of distinct targeted intervention strategies. The present review will focus on recently emerged cytotoxic approaches emphasizing the novel technologies and related limits hindering their application in the clinical setting. Finally, future research directions and emerging opportunities in the field of uPAR targeting are also discussed.

Reusable, Noninvasive, and Sensitive Fluorescence Enhanced ZnO-Nanorod-Based Microarrays for Quantitative Detection of AFP in Human Serum

The fabrication of sensitive protein microarrays such as PCR used in DNA microarray is challenging due to lack of signal amplification. The development of microarrays is utilized to improve the sensitivity and limitations of detection towards primal cancer detection. The sensitivity is enhanced by the use of ZnO-nanorods and is investigated as a substrate which enhance the florescent signal to diagnose the hepatocellular carcinoma (HCC) at early stages. The substrate for deposition of ZnO-nanorods is prepared by the conventional chemical bath deposition method. The resultant highly dense ZnO-nanorods enhance the fluorescent signal 7.2 times as compared to the substrate without ZnO-nanorods. The microarray showed sensitivity of 1504.7 ng ml⁻¹ and limit of detection of 0.1 pg ml⁻¹ in wide dynamic range of 0.05 pg-10 μg ml⁻¹ for alpha fetoprotein (AFP) detection in 10% human serum. This immunoassay was successfully applied for human serum samples to detect tumor marker with good recoveries. The ZnO-nanorod substrate is a simple protein microarray which showed a great promise for developing a low-cost, sensitive, and high-throughput protein assay platform for several applications in both fundamental research and clinical diagnosis.

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.

Differentiating Between Low- and High-grade Glioma Tumors Measuring Apparent Diffusion Coefficient Values in Various Regions of the Brain

Objectives

Our study aimed to apply the apparent diffusion coefficient (ADC) values to quantify the differences between low- and high-grade glioma tumors.

Methods

We conducted a multicenter, retrospective study between September to December 2019. Magnetic resonance imaging (MRI) diffusion-weighted images (DWIs), and the pathologic findings of 56 patients with glioma tumors (low grade = 28 and high grade = 28) were assessed to measure the ADC values in the tumor center, tumor edema, boundary area between tumor with normal tissue, and inside the healthy hemisphere. These values were compared between the two groups, and cut-off values were calculated using the receiver operating characteristic curve.

Results

We saw significant differences between the mean ADC values measured in the tumor center and edema between high- and low-grade tumors (p< 0.005). The ADC values in the boundary area between tumors with normal tissue and inside healthy hemisphere did not significantly differ in the groups. The ADC values at tumor center and edema were higher than 1.12 × 10^-3 mm²/s (sensitivity = 100% and specificity = 96.0%) and 1.15 × 10^-3 mm²/s (sensitivity = 75.0% and specificity = 64.0%), respectively, could be classified as low-grade tumors.

Conclusions

The ADC values from the MRI DWIs in the tumor center and edema could be used as an appropriate method for investigating the differences between low- and high-grade glioma tumors. The ADC values in the boundary area and healthy tissues had no diagnostic values in grading the glioma tumors.

Advantages and challenges in nanomedicines for chronic liver diseases: A hepatologist's perspectives

Chronic liver diseases (CLD) are responsible for significant morbidity and mortality worldwide. CLD patients are at a high risk of developing progressive liver fibrosis, cirrhosis, hepatocellular carcinoma (HCC), and subsequent liver failure. To date, there is no specific and effective therapies exist for patients with various forms of CLD. The application of nanotechnology has emerged as a rapidly developing area of interest for the safe and target-specific delivery of poorly aqueous soluble hepatoprotective agents and nucleic acids (siRNA/miRNAs) in CLD. The nanoparticle combination improves bioavailability and plasma stability of drugs with poor aqueous solubility. However, the extent of successful functional delivery of nanoparticles into hepatocytes is often surprisingly low. High Kupffer cells interaction reduces the nanomedicine efficacy. During fibrosis, the extracellular matrix accumulation in the perisinusoidal space restricts nanoparticle delivery to hepatocytes. The availability and uptake of nanoparticles exposure to different cells in the liver microenvironment is as Kupffer cells > sinusoidal endothelial cells > HSCs > hepatocytes. The most widely used strategy to reduce nanoparticles and macrophages interaction is to coat the particle surface with polyethylene glycol. The cationic charged nanoparticles have increased hepatocyte delivery by increased cellular interaction by disrupting the endosomal system via their pH buffering capacity. The immune clearance and toxicity of nanoparticles are mainly unpredictable. Therefore, more elaborate knowledge on exact cellular uptake and intracellular accumulation, trafficking, and endosomal sorting of nanoparticle is the need of the hour to improve the rational carrier design.

Multifunctional Fe3O4-Au Nanoparticles for the MRI Diagnosis and Potential Treatment of Liver Cancer

Heterodimeric nanoparticles comprising materials with different functionalities are of great interest for fundamental research and biomedical/industrial applications. In this work, Fe₃O₄-Au nano-heterostructures were synthesized by a one-step thermal decomposition method. The hybrid nanoparticles comprise a highly crystalline 12 nm magnetite octahedron decorated with a single noble metal sphere of 6 nm diameter. Detailed analysis of the nanoparticles was performed by UV-visible spectroscopy, magnetometry, calorimetry and relaxometry studies. The cytotoxic effect of the nanoparticles in the human hepatic cell line Huh7 and PLC/PRF/5-Alexander was also assessed. These Fe₃O₄-Au bifunctional nanoparticles showed no significant cytotoxicity in these two cell lines. The nanoparticles showed a good theranostic potential for liver cancer treatment, since the r₂ relaxivity (166.5 mM⁻¹·s⁻¹ and 99.5 mM⁻¹·s⁻¹ in water and HepG2 cells, respectively) is higher than the corresponding values for commercial T₂ contrast agents and the Specific Absorption Rate (SAR) value obtained (227 W/g_Fe) is enough to make them suitable as heat mediators for Magnetic Fluid Hyperthermia. The gold counterpart can further allow the conjugation with different biomolecules and the optical sensing.

Vascular Interventional Radiology-Guided Photothermal Therapy of Colorectal Cancer Liver Metastasis with Theranostic Gold Nanorods

We report sub-100 nm optical/magnetic resonance (MR)/X-ray contrast-bearing theranostic nanoparticles (TNPs) for interventional image-guided photothermal therapy (PTT) of solid tumors. TNPs were composed of Au@Gd2O3:Ln (Ln = Yb/Er) with X-ray contrast (∼486 HU; 1014 NPs/mL, 0.167 nM) and MR contrast (∼1.1 × 108 mM-1 S-1 at 9.4 T field strength). Although TNPs are deposited in tumors following systemic administration via enhanced permeation and retention effect, the delivered dose to tumors is typically low; this can adversely impact the efficacy of PTT. To overcome this limitation, we investigated the feasibility of site-selective hepatic image-guided delivery of TNPs in rats bearing colorectal liver metastasis (CRLM). The mesenteric vein of tumor-bearing rats was catheterized, and TNPs were infused into the liver by accessing the portal vein for site-selective delivery. The uptake of TNPs with hepatic delivery was compared with systemic administration. MR imaging confirmed that delivery via the hepatic portal vein can double the CRLM tumor-to-liver contrast compared with systemic administration. Photothermal ablation was performed by inserting a 100 μm fiber-optic carrying 808 nm light via a JB1, 3-French catheter for 3 min under DynaCT image guidance. Histological analysis revealed that the thermal damage was largely confined to the tumor region with minimal damage to the adjacent liver tissue. Transmission electron microscopy imaging validated the stability of core-shell structure of TNPs in vivo pre- and post-PTT. TNPs comprising Gd-shell-coated Au nanorods can be effectively employed for the site-directed PTT of CRLM by leveraging interventional radiology methods.

Induction of Apoptosis and Inhibition of Invasion in Gastric Cancer Cells by Titanium Dioxide Nanoparticles

Objectives

Nanoparticles induce oxidative stress in cells and damage them through the cell membrane and DNA damage, eventually resulting in cell death. This study aimed to evaluate the effect of titanium dioxide (TiO₂) nanoparticles on apoptosis induction and invasion of gastric cancer cell line, MKN-45.

Methods

We used the MTT assay to assess proliferation of MKN-45 gastric cancer cells after exposure to different forms of TiO₂ nanoparticles including amorph, brookite, anatase, and rutile coated with polyethylene glycol (PEG) and bovine serum albumin (BSA). Ethidium bromide and acridine orange staining were used to visualize cancer cell apoptosis, and the wound healing assay technique (migration test) was used to assay cancer cell invasion.

Results

Viability and proliferation of cancer cells in the presence of various forms of TiO₂ nanoparticles were reduced (p ≤ 0.050). This reduction in cell proliferation and viability was directly related to concentration and duration of exposure to nanoparticles. Induction of cell death was seen in all groups (p ≤ 0.050). Increased cell invasion was seen in PEG-amorph TiO₂ group compared to the control group. Cell invasion was decreased only in the brookite BSA group (p ≤ 0.050).

Conclusions

Various forms of TiO₂ nanoparticles reduced cell proliferation and induced apoptosis in cancer cells. Some forms of TiO₂ nanoparticles such as brookite BSA also inhibited cell invasion. PEG-amorph TiO₂ nanoparticles increased cell invasion. These differences seem to be due to the effects of different configurations of TiO₂ nanoparticles. TiO₂ may provide a new strategy for cancer treatment and more studies are needed.