Size dependent cellular uptake, in vivo fate and light-heat conversion efficiency of gold nanoshells on silica nanorattles

Titanium Dioxide (E171) Induces Toxicity in H9c2 Rat Cardiomyoblasts and Ex Vivo Rat Hearts

Cardiovascular diseases are the leading cause of death worldwide. Food-grade TiO₂ (E171) is the most widely used additive in the food industry. Existing evidence shows TiO₂ nanoparticles reach systemic circulation through biological barriers, penetrate cell membranes, accumulate in cells of different organs, and cause damage; however, their effects on cardiac cells and the development of heart diseases are still unexplored. Therefore, in this work, we tested E171 toxicity in rat cardiomyoblasts and hearts. E171 internalization and impact on cell viability, proliferation, mitochondria, lysosomes, F-actin distribution, and cell morphology were evaluated in H9c2 cells. Additionally, effects of E171 were measured on cardiac function in ex vivo rat hearts. E171 was uptaken by cells and translocated into the cytoplasm. E171 particles changed cell morphology reducing proliferation and metabolic activity. Higher caspase-3 and caspase-9 expression as well as Tunel-positive cells induced by E171 exposure indicate apoptotic death. Mitochondrial and lysosome alterations resulting from mitophagy were detected after 24 and 48 h exposure, respectively. Additionally, high E171 concentrations caused rearrangements of the F-actin cytoskeleton. Finally, hearts exposed to E171 showed impaired cardiac function. These results support E171 toxicity in cardiac cells in vitro altering cardiac function in an ex vivo model, indicating that consumption of this food additive could be toxic and may lead to the development of cardiovascular disease.

Formulation, Cellular Uptake and Cytotoxicity of Thymoquinone-Loaded PLGA Nanoparticles in Malignant Melanoma Cancer Cells

Introduction

Thymoquinone (TQ) is the main active compound extracted from Nigella sativa a traditional herb with wide therapeutic applications and recognizable anticancer properties. This study aimed to formulate and characterize TQ-nanoparticles using PLGA as a biocompatible coating material (TQ-PLGA NPs) with the evaluation of its therapeutic properties in human melanoma cancer cells.

Methods

The TQ-PLGA NPs were prepared and characterized for size, zeta potential, encapsulation efficiency, and release profile.

Results

The particle size was 147.2 nm, with 22.1 positive zeta potential and 96.8% encapsulation efficiency. The NPs released 45.6% of the encapsulated TQ within 3 h followed by characteristic sustained release over 7 days with a total of 69.7% cumulative release. TQ-PLGA NPs were taken up effectively by the cells in a time-dependent manner up to 24 h. Higher cell toxicity was determined within the first 24 h in melanoma cells due to the rapid release of TQ from the NPs and its low stability in the cell culture media.

Conclusion

TQ-PLGA NPs is a potential anticancer agent taking advantage of the sustained release and tailored size that allows accumulation in the cancer tissue by the enhanced permeability and retention effect. However, stability problems of the active ingredient were address in this study and requires further investigation.

A Review on Cancer Therapy Based on the Photothermal Effect of Gold Nanorod

Background:

Cancer causes millions of deaths and huge economic losses every year. The currently practiced methods for cancer therapy have many defects, such as side effects, low curate rate, and discomfort for patients.

Objective:

Herein, we summarize the applications of gold nanorods (AuNRs) in cancer therapy based on their photothermal effect-the conversion of light into local heat under irradiation.

Methods:

The recent advances in the synthesis and regulation of AuNRs, and facile surface functionalization further facilitate their use in cancer treatment. For cancer therapy, AuNRs need to be modified or coated with biocompatible molecules (e.g. polyethylene glycol) and materials (e.g. silicon) to reduce the cytotoxicity and increase their biocompatibility, stability, and retention time in the bloodstream. The accumulation of AuNRs in cancerous cells and tissues is due to the high leakage in tumors or the specific interaction between the cell surface and functional molecules on AuNRs such as antibodies, aptamers, and receptors.

Results:

AuNRs are employed not only as therapeutics to ablate tumors solely based on the heat produced under laser that could denature protein and activate the apoptotic pathway, but also as synergistic therapies combined with photodynamic therapy, chemotherapy, and gene therapy to kill cancer more efficiently. More importantly, other materials like TiO2, graphene oxide, and silicon, etc. are incorporated on the AuNR surface for multimodal cancer treatment with high drug loadings and improved cancer-killing efficiency. To highlight their applications in cancer treatment, examples of therapeutic effects both in vitro and in vivo are presented.

Conclusion:

AuNRs have potential applications for clinical cancer therapy.

Biocompatible CuS-based nanoplatforms for efficient photothermal therapy and chemotherapy in vivo

Near-infrared (NIR) photothermal therapy (PTT) is a new approach to ablate cancer without affecting normal tissues. A pivotal concern of PPT is to develop photo-responsive agents with high biocompatibility as well as effective photothermal conversion efficiency. Copper sulfide (CuS) nanoparticles prepared are characterized by their low synthesis cost, wide NIR absorption range, good biocompatibility and favorable NIR photothermal conversion efficiency. CuS nanoparticles were then coated with mesoporous silicon dioxide (SiO₂) by the Stober method, and further loaded with anticancer drug doxorubicin (DOX). The nanocomposites obtained were named CuS@MSN-DOX. The infrared thermal imaging of CuS@MSN-DOX demonstrated its favorable photothermal efficacy. The potential of CuS@MSN-DOX utilized as a multifunctional platform for combined PPT and chemotherapy was exploited both at the cell level and in a mice model. The result demonstrated that CuS@MSN-DOX was endowed with the synergistic effect of chemo-photothermal therapy, which confirmed that it is a promising candidate for combined therapy of cancer.

Dual Roles of Graphene Oxide To Attenuate Inflammation and Elicit Timely Polarization of Macrophage Phenotypes for Cardiac Repair

Development of localized inflammatory environments by M1 macrophages in the cardiac infarction region exacerbates heart failure after myocardial infarction (MI). Therefore, the regulation of inflammation by M1 macrophages and their timely polarization toward regenerative M2 macrophages suggest an immunotherapy. Particularly, controlling cellular generation of reactive oxygen species (ROS), which cause M1 differentiation, and developing M2 macrophage phenotypes in macrophages propose a therapeutic approach. Previously, stem or dendritic cells were used in MI for their anti-inflammatory and cardioprotective potentials and showed inflammation modulation and M2 macrophage progression for cardiac repair. However, cell-based therapeutics are limited due to invasive cell isolation, time-consuming cell expansion, labor-intensive and costly ex vivo cell manipulation, and low grafting efficiency. Here, we report that graphene oxide (GO) can serve as an antioxidant and attenuate inflammation and inflammatory polarization of macrophages via reduction in intracellular ROS. In addition, GO functions as a carrier for interleukin-4 plasmid DNA (IL-4 pDNA) that propagates M2 macrophages. We synthesized a macrophage-targeting/polarizing GO complex (MGC) and demonstrated that MGC decreased ROS in immune-stimulated macrophages. Furthermore, DNA-functionalized MGC (MGC/IL-4 pDNA) polarized M1 to M2 macrophages and enhanced the secretion of cardiac repair-favorable cytokines. Accordingly, injection of MGC/IL-4 pDNA into mouse MI models attenuated inflammation, elicited early polarization toward M2 macrophages, mitigated fibrosis, and improved heart function. Taken together, the present study highlights a biological application of GO in timely modulation of the immune environment in MI for cardiac repair. Current therapy using off-the-shelf material GO may overcome the shortcomings of cell therapies for MI.

Low density lipoprotein modified silica nanoparticles loaded with docetaxel and thalidomide for effective chemotherapy of liver cancer

In the present study, we successfully developed a docetaxel (DTX) and thalidomide (TDD) co-delivery system based on low density lipoprotein (LDL) modified silica nanoparticles (LDL/SLN/DTX/TDD). By employing the tumor homing property of LDL and the drug-loading capability of silica nanoparticles, the prepared LDL/SLN/DTX/TDD was expected to locate and specifically deliver the loaded drugs (DTX and TDD) to achieve effective chemotherapy of liver cancer. In vitro analysis revealed that nano-sized LDL/SLN/DTX/TDD with decent drug loading capabilities was able to increase the delivery efficiency by targeting the low density lipoprotein receptors, which were overexpressed on HepG2 human hepatocellular liver carcinoma cell line, which exerted better cytotoxicity than unmodified silica nanoparticles and free drugs. In vivo imaging and anti-cancer assays also confirmed the preferable tumor-homing and synergetic anti-cancer effects of LDL/SLN/DTX/TDD.

Noninvasive rapid bacteria-killing and acceleration of wound healing through photothermal/photodynamic/copper ion synergistic action of a hybrid hydrogel

Bacterial infection often delays healing of wounded tissues and so it is essential to improve the antibacterial efficiency in situ.

A Comparative Study of Clinical Intervention and Interventional Photothermal Therapy for Pancreatic Cancer

Although nanoparticle-based photothermal therapy (PTT) has been intensively investigated recently, its comparative efficiency with any clinical cancer treatments has been rarely explored. Herein for the first time we report a systematic comparative study of clinical iodine-125 (¹²⁵ I) interstitial brachytherapy (IBT-125-I) and interventional PTT (IPTT) in an orthotopic xenograft model of human pancreatic cancer. IPTT, based on the nanoparticles composing of anti-urokinase plasminogen activator receptor (uPAR) antibody, polyethylene glycol (PEG), and indocyanine green (ICG) modified gold nanoshells (hereinafter uIGNs), is directly applied to local pancreatic tumor deep in the abdomen. In comparison to IBT-125-I, a 25% higher median survival rate of IPTT with complete ablation by one-time intervention has been achieved. The IPTT could also inhibit pancreatic tumor metastasis which can be harnessed for effective cancer immunotherapy. All results show that this IPTT is a safe and radical treatment for eradicating tumor cells, and may benefit future clinical pancreatic cancer patients.

Cellular Uptake and Delivery-Dependent Effects of Tb3+-Doped Hydroxyapatite Nanorods

With the increasing interest in hydroxyapatite (HA) nanostructures for use in biomedicine, the systematic evaluation of their potential effects on biological systems is becoming critically important. In this work, we report the in vitro cellular uptake, in vivo tissue distributions and toxicity of Tb3+-doped HA (HA-Tb) after short-, intermediate-, and long-term exposure. Transmission electron microscopy analysis indicated that HA-Tb was taken up by cells via vesicle endocytosis. Cell proliferation and cytotoxicity assay, combined with confocal laser scanning microscopy, indicated excellent cell viability with no changes in cell morphology at the examined doses. Three HA-Tb delivery methods (intraperitoneal, intragastric, and intravenous) resulted in similar time-dependent tissue distributions, while intraperitoneal injection produced the highest bioavailability. HA-Tb initially accumulated in livers and intestines of rats (4 h to one day after administration), then became increasingly distributed in the kidney and bladder (seven days), and finally decreased in all tissues after 30 to 90 days. No histopathological abnormalities or lesions related to treatment with HA-Tb were observed. These results suggest that HA-Tb has minimal in vitro and in vivo toxicity, regardless of the delivery mode, time, and dose. The findings provide a foundation for the design and development of HA for biological applications.

Well-Defined Peapod-like Magnetic Nanoparticles and Their Controlled Modification for Effective Imaging Guided Gene Therapy

Due to their unique properties, one-dimensional (1D) magnetic nanostructures are of great significance for biorelated applications. A facile and straightforward strategy to fabricate 1D magnetic structure with special shapes is highly desirable. In this work, well-defined peapod-like 1D magnetic nanoparticles (Fe3O4@SiO2, p-FS) are readily synthesized by a facile method without assistance of any templates, magnetic string or magnetic field. There are few reports on 1D gene carriers based on Fe3O4 nanoparticles. BUCT-PGEA (ethanolamine-functionalized poly(glycidyl methacrylate) is subsequently grafted from the surface of p-FS nanoparticles by atom transfer radical polymerization to construct highly efficient gene vectors (p-FS-PGEA) for effective biomedical applications. Peapod-like p-FS nanoparticles were proven to largely improve gene transfection performance compared with ordinary spherical Fe3O4@SiO2 nanoparticles (s-FS). External magnetic field was also utilized to further enhance the transfection efficiency. Moreover, the as-prepared p-FS-PGEA gene carriers could combine the magnetic characteristics of p-FS to well achieve noninvasive magnetic resonance imaging (MRI). We show here novel and multifunctional magnetic nanostructures fabricated for biomedical applications that realized efficient gene delivery and real-time imaging at the same time.

Copper-Based Nanomaterials for Cancer Imaging and Therapy

Copper based nanoparticles (NPs) have attracted increased attention for biomedical applications. Copper chalcogenide NPs exhibit strong absorption in near-infrared region, demonstrate highly efficient light-to-heat transformation under near-infrared laser irradiation, and cause selective thermal destruction to the tumor. Smaller copper NPs display fluorescence signal and capability for optical imaging. Copper based NPs also serve as a versatile vehicle for drug delivery and image-guided therapy. This review covers recent advances related to the biomedical application of copper based NPs, with a focus on cancer imaging and therapy. We also discuss challenges to their successful clinical translation.

A Multilaboratory Toxicological Assessment of a Panel of 10 Engineered Nanomaterials to Human Health--ENPRA Project--The Highlights, Limitations, and Current and Future Challenges

ENPRA was one of the earlier multidisciplinary European Commission FP7-funded projects aiming to evaluate the risks associated with nanomaterial (NM) exposure on human health across pulmonary, cardiovascular, hepatic, renal, and developmental systems. The outputs from this project have formed the basis of this review. A retrospective interpretation of the findings across a wide range of in vitro and in vivo studies was performed to identify the main highlights from the project. In particular, focus was placed on informing what advances were made in the hazard assessment of NM, as well as offering some suggestions on the future of "nanotoxicology research" based on these observations, shortcomings, and lessons learned from the project. A number of issues related to the hazard assessment of NM are discussed in detail and include use of appropriate NM for nanotoxicology investigations; characterization and dispersion of NM; use of appropriate doses for all related investigations; need for the correct choice of experimental models for risk assessment purposes; and full understanding of the test systems and correct interpretation of data generated from in vitro and in vivo systems. It is hoped that this review may assist in providing information in the implementation of guidelines, model systems, validation of assessment methodology, and integrated testing approaches for risk assessment of NM. It is vital to learn from ongoing and/or completed studies to avoid unnecessary duplication and offer suggestions that might improve different aspects of experimental design.

Polycation-functionalized gold nanoparticles with different morphologies for superior gene transfection

Favorable physical and chemical properties endow Au nanoparticles (Au NPs) with various biomedical applications. After appropriate surface functionalization, Au NPs could construct promising drug/gene carriers with multiple functions. There is now ample evidence that physicochemical properties, such as size, shape, and surface chemistry, can dramatically influence the behaviors of Au NPs in biological systems. Investigation of these parameters could be fundamentally important for the application of Au NPs as drug/gene carriers. In this work, we designed a series of novel gene carriers employing polycation-functionalized Au NPs with five different morphologies (including Au nanospheres, Au nano-octahedra, arrow-headed Au nanorods, and Au nanorods with different aspect ratios). The effects of the particle size and shape of these different carriers on gene transfection were investigated in detail. The morphology of Au NPs is demonstrated to play an important role in gene transfection. The most efficient gene carriers are those fabricated with arrow-headed Au nanorods. Au nanosphere-based carriers exhibit the poorest performance in gene transfection. In addition, Au nanorods with smaller aspect ratios perform better than longer ones. These results may provide new avenues to develop promising gene carriers and gain useful information on the interaction of Au NPs with biological systems.

Plasmonic copper sulfide nanocrystals exhibiting near-infrared photothermal and photodynamic therapeutic effects

Recently, plasmonic copper sulfide (Cu2-xS) nanocrystals (NCs) have attracted much attention as materials for photothermal therapy (PTT). Previous reports have correlated photoinduced cell death to the photothermal heat mechanism of these NCs, and no evidence of their photodynamic properties has been reported yet. Herein we have prepared physiologically stable near-infrared (NIR) plasmonic copper sulfide NCs and analyzed their photothermal and photodynamic properties, including therapeutic potential in cultured melanoma cells and a murine melanoma model. Interestingly, we observe that, besides a high PTT efficacy, these copper sulfide NCs additionally possess intrinsic NIR induced photodynamic activity, whereupon they generate high levels of reactive oxygen species. Furthermore, in vitro and in vivo acute toxic responses of copper sulfide NCs were also elicited. This study highlights a mechanism of NIR light induced cancer therapy, which could pave the way toward more effective nanotherapeutics.

Facile synthesis of a highly luminescent carbon dot@silica nanorattle for in vivo bioimaging

Carbon dots embedded in silica nanorattle (CDs@SN) nanocomposites with high luminescence are synthesized and exhibit brighter fluorescence in vitro and in vivo than CDs alone.

Design of hybrid nanovehicles for remotely triggered drug release: an overview

This review addresses the advantages of remote triggers, e.g. ultrasounds, near infrared light and alternating magnetic fields, the fabrication of the hybrid nanovehicles, the release mechanisms and the next challenges.

A facile strategy to functionalize gold nanorods with polycation brushes for biomedical applications

The fabrication of highly efficient nonviral gene carriers with low cytotoxicity remains a challenge in gene therapy. This paper reports a facile strategy to combine the advantages of gold nanorods (Au NRs) and polycations through surface functionalization. Different Au NR carriers with a controlled amount of poly(2-(N,N-dimethyl amino)ethyl methacrylate) (PDAEMA) brushes could be readily synthesized via surface-initiated atom transfer radical polymerization to achieve optimized nanohybrids for gene transfection. The obtained gene carriers demonstrate much higher gene transfection efficiency and lower cytotoxicity compared with polyethylenimine (∼25kDa, gold standard of nonviral gene vector) in both COS7 and HepG2 cell lines. In addition, the potential of the PDMAEMA-grafted Au NR carriers to be utilized as a computed tomography contrast agent for the imaging of cancer cells has also been investigated. This strategy may realize the gene therapy and real-time imaging within one nanostructure and facilitate biomedical applications.

Upconverting and NIR emitting rare earth based nanostructures for NIR-bioimaging

In recent years, significant progress was achieved in the field of nanomedicine and bioimaging, but the development of new biomarkers for reliable detection of diseases at an early stage, molecular imaging, targeting and therapy remains crucial. The disadvantages of commonly used organic dyes include photobleaching, autofluorescence, phototoxicity and scattering when UV (ultraviolet) or visible light is used for excitation. The limited penetration depth of the excitation light and the visible emission into and from the biological tissue is a further drawback with regard to in vivo bioimaging. Lanthanide containing inorganic nanostructures emitting in the near-infrared (NIR) range under NIR excitation may overcome those problems. Due to the outstanding optical and magnetic properties of lanthanide ions (Ln(3+)), nanoscopic host materials doped with Ln(3+), e.g. Y2O3:Er(3+),Yb(3+), are promising candidates for NIR-NIR bioimaging. Ln(3+)-doped gadolinium-based inorganic nanostructures, such as Gd2O3:Er(3+),Yb(3+), have a high potential as opto-magnetic markers allowing the combination of time-resolved optical imaging and magnetic resonance imaging (MRI) of high spatial resolution. Recent progress in our research on over-1000 nm NIR fluorescent nanoprobes for in vivo NIR-NIR bioimaging will be discussed in this review.

Multifunctional Fe3O4@P(St/MAA)@chitosan@Au core/shell nanoparticles for dual imaging and photothermal therapy

Merging different components into a single nanoparticle can exhibit profound impact on various biomedical applications including diagnostics, imaging, and therapy. However, retaining the unique properties of each component after integration has proven to be a significant challenge. Our previous research demonstrated that gold nanoshells on polystyrene spheres have potential in photohermal therapy. Here, we report a facile and green strategy to synthesize a multifunctional nanocomposite with Fe3O4 core coated gold nanoshells as dual imaging probes and photothermal agents. The as-prepared nanoparticles exhibit well-defined structure and excellent physical properties such as magnetic and plasmonic activities. Therefore, they were applied as contrast agents in magnetic resonance imaging (MRI) and dark field imaging (DFI). Besides, we demonstrated their potential application in photothermal therapy. Moreover, the obtained multifunctional nanoparticles have shown excellent biocompatibility for their low cytotoxicity and hemolyticity.

Emerging in vitro models for safety screening of high-volume production nanomaterials under environmentally relevant exposure conditions

The rising production of nanomaterial-based consumer products has raised safety concerns. Testing these with animal and other direct models is neither ethically nor economically viable, nor quick enough. This review aims to discuss the strength of in vitro testing, including the use of 2D and 3D cultures, stem cells, and tissue constructs, etc., which would give fast and repeatable answers of a highly specific nature, while remaining relevant to in vivo outcomes. These results can then be combined and the overall toxicity predicted with relative accuracy. Such in vitro models can screen potentially toxic nanomaterials which, if required, can undergo further stringent studies in animals. The cyto- and phototoxicity of some high-volume production nanomaterials, using in vitro models, is also reviewed.

Self-templating synthesis of hollow mesoporous silica and their applications in catalysis and drug delivery

Hollow mesoporous silica materials have been intensively pursued because of their unique properties for various applications. Yolk/shell structured hollow mesoporous silica with functional cores inside their hollow interior can further broaden the applications of hollow mesoporous silica. The self-templating strategy has been developed as one of the most important strategies to effectively fabricate hollow mesoporous silicas and their yolk/shell counterparts. In this feature article, we provide an overview of advances in the self-templating synthesis of hollow mesoporous silica based on the following three strategies: surface-protected etching, structural difference-based selective etching, and cationic surfactant assisted self-templating. We then discuss some important applications of these self-templating strategy-derived hollow mesoporous silicas, such as nanoreactors for confined catalysis and multifunctional platforms for combined therapy. Finally, some perspectives for the future development of this active research field are provided.

Nanometric gold in cancer nanotechnology: current status and future prospect

Objectives

This review elaborate on modified gold nanoparticulate concept in oncology, provides an overview of the use of gold nanoparticles in cancer treatment and discusses their potential applications and clinical benefits.

Key findings

Modified gold nanoparticles (e.g. rod, multipod and star or a hollow structure such as shell, box and cage) have promising applications in the fields of drug delivery and photothermal therapy in oncology due to their unique optical and photothermal properties and their ability to modify the surface and conjugate drugs/molecules with gold nanomaterial. Modified gold nanoparticles exhibit strong light absorption in the near-infrared region in which light can penetrate deeply into soft tissue. Moreover, recent advances have opened the way to site-specific delivery by gold nanoparticle.

Summary

Recent research and development in cancer-targeted gold nanovectors shows promise for maximizing the efficacy of anti-cancer drugs while decreasing their harmful systemic effects in chemotherapy. Moreover, gold nanoparticles can also serve as cancer therapeutic.

Histological evaluation of the biocompatibility of polyurea crosslinked silica aerogel implants in a rat model: a pilot study

Background

Aerogels are a versatile group of nanostructured/nanoporous materials with physical and chemical properties that can be adjusted to suit the application of interest. In terms of biomedical applications, aerogels are particularly suitable for implants such as membranes, tissue growth scaffolds, and nerve regeneration and guidance inserts. The mesoporous nature of aerogels can also be used for diffusion based release of drugs that are loaded during the drying stage of the material. From the variety of aerogels polyurea crosslinked silica aerogels have the most potential for future biomedical applications and are explored here.

Methodology

This study assessed the short and long term biocompatibility of polyurea crosslinked silica aerogel implants in a Sprague-Dawley rat model. Implants were inserted at two different locations a) subcutaneously (SC), at the dorsum and b) intramuscularly (IM), between the gluteus maximus and biceps femoris of the left hind extremity. Nearby muscle and other internal organs were evaluated histologically for inflammation, tissue damage, fibrosis and movement (travel) of implant.

Conclusion/Significance

In general polyurea crosslinked silica aerogel (PCSA) was well tolerated as a subcutaneous and an intramuscular implant in the Sprague-Dawley rat with a maximum incubation time of twenty months. In some cases a thin fibrous capsule surrounded the aerogel implant and was interpreted as a normal response to foreign material. No noticeable toxicity was found in the tissues surrounding the implants nor in distant organs. Comparison was made with control rats without any implants inserted, and animals with suture material present. No obvious or noticeable changes were sustained by the implants at either location. Careful necropsy and tissue histology showed age-related changes only. An effective sterilization technique for PCSA implants as well as staining and sectioning protocol has been established. These studies further support the notion that silica-based aerogels could be useful as biomaterials.