Gold nanoparticles as contrast agents in x-ray imaging and computed tomography

Gram-Scale Synthesis of Renal-Clearable Tantalum Nanodots with High Water Solubility for Computed Tomography Imaging In Vivo

Tantalum (Ta) emerges as a promising element for advanced computed tomography (CT) imaging probes owing to its high X-ray attenuation coefficient and excellent biocompatibility. Nevertheless, the synthesis of renally clear Ta-based imaging probes through simple methods remains a significant challenge. Herein, we introduce a simple and gram-scale approach for the synthesis of renal-clearable Ta nanodots with high water solubility for CT imaging in vivo. The Ta nanodots, coordination polymers, are fabricated via coordination reactions involving Ta(OH)5, citric acid (CA), and hydrogen peroxide. The Ta nanodots exhibit an ultrasmall hydrodynamic diameter (2.8 nm), high water solubility (1.88 g/mL, 688 mg Ta/mL), superior X-ray absorption capacity, gram-scale production capability (>10 g in lab synthesis), renal-clearable ability, and good biocompatibility. The Ta nanodots possess superior CT imaging efficacy across diverse tube voltages, enabling highly sensitive gastrointestinal CT imaging, renal CT imaging, and CT angiography (CTA). Moreover, Ta nanodots maintain robust CT imaging capabilities even at high X-ray energies, and Ta nanodots-based spectral CT achieves metallic artifacts-minimized CTA. The proposed Ta nanodots present substantial potential as a potent CT imaging probe for diagnosing various diseases.

High resolution imaging of human development: shedding light on contrast agents

BACKGROUND

Visualizing (micro)vascular structures remains challenging for researchers and clinicians due to limitations in traditional radiological imaging methods. Exploring the role of vascular development in craniofacial malformations in experimental settings can enhance understanding of these processes, with the effectiveness of high-resolution imaging techniques being crucial for successful research in this field. Micro-CT imaging offers 3D microstructural insights, but requires contrast-enhancing staining agents (CESAs) for visualizing (micro)-vascular tissues, known as contrast-enhanced micro-CT (CECT). As effective contrast agents are crucial for optimal visualization, this review focuses on comparative studies investigating such agents for micro-vascular tissue imaging using micro-CT. Furthermore, we demonstrate the utilization of B-Lugol solution as a promising contrast agent for acquiring high-quality micro-CT images of (micro)vascular structures in human embryonic samples.

METHOD

This scoping review followed Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols. PubMed database provided relevant articles, screened initially by title and abstract. Inclusion and exclusion criteria defined outcomes of interest.

RESULTS

From an initial search, 273 records were identified, narrowed down to 9 articles after applying our criteria. Additionally, two articles were added through citation searching. This, a total of 11 articles were incorporated in this study.

CONCLUSION

This micro-CT contrast agent review underscores the need for tailored choices based on research goals. Both Barium sulfate and Iodine-based agents showing excellent results, providing high resolution (micro) vascular content, especially in ex-vivo specimens. However, careful consideration of protocols and tissue characteristics remains imperative for optimizing the effectiveness of micro-CT imaging for the study of cranio-facial vascular development.

To see or not to see: In vivo nanocarrier detection methods in the brain and their challenges

Nanoparticles have a great potential to significantly improve the delivery of therapeutics to the brain and may also be equipped with properties to investigate brain function. The brain, being a highly complex organ shielded by selective barriers, requires its own specialized detection system. However, a significant hurdle to achieve these goals is still the identification of individual nanoparticles within the brain with sufficient cellular, subcellular, and temporal resolution. This review aims to provide a comprehensive summary of the current knowledge on detection systems for tracking nanoparticles across the blood-brain barrier and within the brain. We discuss commonly employed in vivo and ex vivo nanoparticle identification and quantification methods, as well as various imaging modalities able to detect nanoparticles in the brain. Advantages and weaknesses of these modalities as well as the biological factors that must be considered when interpreting results obtained through nanotechnologies are summarized. Finally, we critically evaluate the prevailing limitations of existing technologies and explore potential solutions.

Radiolabeled multi-layered coated gold nanoparticles as potential biocompatible PET/SPECT tracers

The demand for tailored, disease-adapted, and easily accessible radiopharmaceuticals is one of the most persistent challenges in nuclear imaging precision medicine. The aim of this work was to develop two multimodal radiotracers applicable for both SPECT and PET techniques, which consist of a gold nanoparticle core, a shell involved in radioisotope entrapment, peripherally placed targeting molecules, and biocompatibilizing polymeric sequences. Shell decoration with glucosamine units located in sterically hindered molecular environments is expected to result in nanoparticle accumulation in high-glucose-consuming areas. Gold cores were synthesized using the Turkevich method, followed by citrate substitution with linear PEG α,ω-functionalized with thiol and amine groups. The free amine groups facilitated the binding of branched polyethyleneimine through an epoxy ring-opening reaction by using PEG α,ω-diglycidyl ether as a linker. Afterwards, the glucose-PEG-epoxy prepolymer has been grafted onto the surface of AuPEG-PEI conjugates. Finally, the AuPEG-PEI-GA conjugates were radiolabeled with 99mTc or 68Ga. Instant thin-layer chromatography was used to evaluate the radiolabeling yield. The biocompatibility of non-labeled and 99mTc or 68Ga labeled nanoparticles was assessed on normal fibroblasts. The 99mTc complexes remained stable for over 22 hours, while the 68Ga containing ones revealed a slight decrease in stability after 1 hour.

Hybridized quantum dot, silica, and gold nanoparticles for targeted chemo-radiotherapy in colorectal cancer theranostics

Multimodal nanoparticles, utilizing quantum dots (QDs), mesoporous silica nanoparticles (MSNs), and gold nanoparticles (Au NPs), offer substantial potential as a smart and targeted drug delivery system for simultaneous cancer therapy and imaging. This method entails coating magnetic GZCIS/ZnS QDs with mesoporous silica, loading epirubicin into the pores, capping with Au NPs, PEGylation, and conjugating with epithelial cell adhesion molecule (EpCAM) aptamers to actively target colorectal cancer (CRC) cells. This study showcases the hybrid QD@MSN-EPI-Au-PEG-Apt nanocarriers (size ~65 nm) with comprehensive characterizations post-synthesis. In vitro studies demonstrate the selective cytotoxicity of these targeted nanocarriers towards HT-29 cells compared to CHO cells, leading to a significant reduction in HT-29 cell survival when combined with irradiation. Targeted delivery of nanocarriers in vivo is validated by enhanced anti-tumor effects with reduced side effects following chemo-radiotherapy, along with imaging in a CRC mouse model. This approach holds promise for improved CRC theranostics.

Inorganic nanocarriers for siRNA delivery for cancer treatments

RNA interference is one of the emerging methodologies utilized in the treatment of a wide variety of diseases including cancer. This method specifically uses therapeutic RNAs (TpRNAs) like small interfering RNAs (siRNAs) to regulate/silence the cancer-linked genes, thereby minimizing the distinct activities of the cancer cells while aiding in their apoptosis. But, many complications arise during the transport/delivery of these TpRNAs that include poor systemic circulation, instability/degradation inside the body environment, no targeting capacity and also low cellular internalization. These difficulties can be overcome by using nanocarriers to deliver the TpRNAs inside the cancer cells. The following are the various categories of nanocarriers-viral vectors (e.g. lentivirus and adenovirus) and non-viral nanocarriers (self-assembling nanocarriers and inorganic nanocarriers). Viral vectors suffer from disadvantages like high immunogenicity compared to the non-viral nanocarriers. Among non-viral nanocarriers, inorganic nanocarriers gained significant attention as their inherent properties (like magnetic properties) can aid in the effective cellular delivery of the TpRNAs. Most of the prior reports have discussed about the delivery of TpRNAs through self-assembling nanocarriers; however very few have reviewed about their delivery using the inorganic nanoparticles. Therefore, in this review, we have mainly focussed on the delivery of TpRNAs-i.e. siRNA, especially programmed death ligand-1 (PD-L1), survivin, B-cell lymphoma-2 (Bcl-2), vascular endothelial growth factor and other siRNAs using the inorganic nanoparticles-mainly magnetic, metal and silica nanoparticles. Moreover, we have also discussed about the combined delivery of these TpRNAs along with chemotherapeutic drugs (mainly doxorubicin) andin vitroandin vivotherapeutic effectiveness.

Leveraging 3D Bioprinting and Photon-Counting Computed Tomography to Enable Noninvasive Quantitative Tracking of Multifunctional Tissue Engineered Constructs

3D bioprinting is revolutionizing the fields of personalized and precision medicine by enabling the manufacturing of bioartificial implants that recapitulate the structural and functional characteristics of native tissues. However, the lack of quantitative and noninvasive techniques to longitudinally track the function of implants has hampered clinical applications of bioprinted scaffolds. In this study, multimaterial 3D bioprinting, engineered nanoparticles (NPs), and spectral photon-counting computed tomography (PCCT) technologies are integrated for the aim of developing a new precision medicine approach to custom-engineer scaffolds with traceability. Multiple CT-visible hydrogel-based bioinks, containing distinct molecular (iodine and gadolinium) and NP (iodine-loaded liposome, gold, methacrylated gold (AuMA), and Gd2 O3 ) contrast agents, are used to bioprint scaffolds with varying geometries at adequate fidelity levels. In vitro release studies, together with printing fidelity, mechanical, and biocompatibility tests identified AuMA and Gd2 O3 NPs as optimal reagents to track bioprinted constructs. Spectral PCCT imaging of scaffolds in vitro and subcutaneous implants in mice enabled noninvasive material discrimination and contrast agent quantification. Together, these results establish a novel theranostic platform with high precision, tunability, throughput, and reproducibility and open new prospects for a broad range of applications in the field of precision and personalized regenerative medicine.

CT and X-ray contrast agents: Current clinical challenges and the future of contrast

Computed tomography (CT) is a powerful and widely used imaging technique in modern medicine. However, it often requires the use of contrast agents to visualize structures with similar radiographic density. Unfortunately, current clinical contrast agents (CAs) for CT have remained largely unchanged for decades and come with several significant drawbacks, including serious nephrotoxicity and short circulation half-lives. The next generation of CT radiocontrast agents should strive to be long-circulating, non-toxic, and non-immunogenic. Nanoparticle contrast agents have shown promise in recent years and are likely to comprise the majority of next-generation CT contrast agents. This review highlights the fundamental mechanism and background of X-ray and contrast agents. It also focuses on the challenges associated with current clinical contrast agents and provides a brief overview of potential future agents that are based on various materials such as lipids, polymers, dendrimers, metallic, and non-metallic inorganic nanoparticles (NPs). STATEMENT OF SIGNIFICANCE: We realized a need for clarification on a number of concerns related to the use of iodinated contrast material as debates regarding the safety of these agents with patients with kidney disease, shellfish allergies, and thyroid dysfunction remain ongoing in medical practice. This review was partially inspired by debates witnessed in medical practice regarding outdated misconceptions of contrast material that warrant clarification in translational and clinical arenas. Given that conversation around currently available agents is at somewhat of a high water mark, and nanoparticle research has now reached an unprecedented number of readers, we find that this review is timely and unique in the context of recent discussions in the field.

Multispectral optoacoustic tomography is more sensitive than micro-computed tomography for tracking gold nanorod labelled mesenchymal stromal cells

Tracking the fate of therapeutic cell types is important for assessing their safety and efficacy. Bioluminescence imaging (BLI) is an effective cell tracking technique, but poor spatial resolution means it has limited ability to precisely map cells in vivo in 3D. This can be overcome by using a bimodal imaging approach that combines BLI with a technique capable of generating high-resolution images. Here we compared the effectiveness of combining either multispectral optoacoustic tomography (MSOT) or micro-computed tomography (micro-CT) with BLI for tracking the fate of luciferase+ human mesenchymal stromal cells (MSCs) labelled with gold nanorods. Following subcutaneous administration in mice, the MSCs could be readily detected with MSOT but not with micro-CT. We conclude that MSOT is more sensitive than micro-CT for tracking gold nanorod-labelled cells in vivo and depending on the route of administration, can be used effectively with BLI to track MSC fate in mice.

Optically active organic and inorganic nanomaterials for biological imaging applications: A review

Recent advancements in the field of nanotechnology have enabled targeted delivery of drug agents in vivo with minimal side effects. The use of nanoparticles for bio-imaging has revolutionized the field of nanomedicine by enabling non-invasive targeting and selective delivery of active drug moieties in vivo. Various inorganic nanomaterials like mesoporous silica nanoparticles, gold nanoparticles, magnetite nanoparticles graphene-based nanomaterials etc., have been created for multimodal therapies with varied multi-imaging modalities. These nanomaterials enable us to overcome the disadvantages of conventional imaging contrast agents (organic dyes) such as lack of stability in vitro and in vivo, high reactivity, low-quantum yield and poor photo stability. Inorganic nanomaterials can be easily fabricated, functionalised and modified as per requirements. Recently, advancements in synthesis techniques, such as the ability to generate molecules and construct supramolecular structures for specific functionalities, have boosted the usage of engineered nanomaterials. Their intrinsic physicochemical properties are unique and they possess excellent biocompatibility. Inorganic nanomaterial research has developed as the most actively booming research fields in biotechnology and biomedicine. Inorganic nanomaterials like gold nanoparticles, magnetic nanoparticles, mesoporous silica nanoparticles, graphene-based nanomaterials and quantum dots have shown excellent use in bioimaging, targeted drug delivery and cancer therapies. Biocompatibility of nanomaterials is an important aspect for the evolution of nanomaterials in the bench to bedside transition. The conduction of thorough and meticulous study for safety and efficacy in well-designed clinical trials is absolutely necessary to determine the functional and structural relationship between the engineered nanomaterial and its toxicity. In this article an attempt is made to throw some light on the current scenario and developments made in the field of nanomaterials in bioimaging.

Barium sulfate and pigment admixture for photoacoustic and x-ray contrast imaging of the gut

Significance

X-ray imaging is frequently used for gastrointestinal imaging. Photoacoustic imaging (PAI) of the gastrointestinal tract is an emerging approach that has been demonstrated for preclinical imaging of small animals. A contrast agent active in both modalities could be useful for imaging applications.

Aim

We aimed to develop a dual-modality contrast agent comprising an admixture of barium sulfate with pigments that absorb light in the second near-infrared region (NIR-II), for preclinical imaging with both x-ray and PAI modalities.

Approach

Eleven different NIR-II dyes were evaluated after admixture with a 40% w/v barium sulfate mixture. The resulting NIR-II absorption in the soluble fraction and in the total mixture was characterized. Proof-of-principle imaging studies in mice were carried out.

Results

Pigments that produced more uniform suspensions were assessed further for photoacoustic contrast signal at a wavelength of 1064 nm that corresponds to the output of the Nd:YAG laser used. Phantom imaging studies demonstrated that the pigment-barium sulfate mixture generated imaging contrast in both x-ray and PAI modalities. The optimal pigment selected for further study was a cyanine tetrafluoroborate salt. Ex-vivo and whole-body mouse imaging demonstrated that photoacoustic and x-ray contrast signals co-localized in the intestines for both imaging modalities.

Conclusion

These data demonstrate that commercially-available NIR-II pigments can simply be admixed with barium sulfate to generate a dual-modality contrast agent appropriate for small animal gastrointestinal imaging.

Application of Nanoparticles in the Diagnosis of Gastrointestinal Diseases: A Complete Future Perspective

The diagnosis of gastrointestinal (GI) diseases currently relies primarily on invasive procedures like digestive endoscopy. However, these procedures can cause discomfort, respiratory issues, and bacterial infections in patients, both during and after the examination. In recent years, nanomedicine has emerged as a promising field, providing significant advancements in diagnostic techniques. Nanoprobes, in particular, offer distinct advantages, such as high specificity and sensitivity in detecting GI diseases. Integration of nanoprobes with advanced imaging techniques, such as nuclear magnetic resonance, optical fluorescence imaging, tomography, and optical correlation tomography, has significantly enhanced the detection capabilities for GI tumors and inflammatory bowel disease (IBD). This synergy enables early diagnosis and precise staging of GI disorders. Among the nanoparticles investigated for clinical applications, superparamagnetic iron oxide, quantum dots, single carbon nanotubes, and nanocages have emerged as extensively studied and utilized agents. This review aimed to provide insights into the potential applications of nanoparticles in modern imaging techniques, with a specific focus on their role in facilitating early and specific diagnosis of a range of GI disorders, including IBD and colorectal cancer (CRC). Additionally, we discussed the challenges associated with the implementation of nanotechnology-based GI diagnostics and explored future prospects for translation in this promising field.

Molecularly Imprinted Carriers for Diagnostics and Therapy-A Critical Appraisal

Simultaneous diagnostics and targeted therapy provide a theranostic approach, an instrument of personalized medicine-one of the most-promising trends in current medicine. Except for the appropriate drug used during the treatment, a strong focus is put on the development of effective drug carriers. Among the various materials applied in the production of drug carriers, molecularly imprinted polymers (MIPs) are one of the candidates with great potential for use in theranostics. MIP properties such as chemical and thermal stability, together with capability to integrate with other materials are important in the case of diagnostics and therapy. Moreover, the MIP specificity, which is important for targeted drug delivery and bioimaging of particular cells, is a result of the preparation process, conducted in the presence of the template molecule, which often is the same as the target compound. This review focused on the application of MIPs in theranostics. As a an introduction, the current trends in theranostics are described prior to the characterization of the concept of molecular imprinting technology. Next, a detailed discussion of the construction strategies of MIPs for diagnostics and therapy according to targeting and theranostic approaches is provided. Finally, frontiers and future prospects are presented, stating the direction for further development of this class of materials.

Illuminating and Radiosensitizing Tumors with 2DG-Bound Gold-Based Nanomedicine for Targeted CT Imaging and Therapy

Although radiotherapy is one of the most important curative treatments for cancer, its clinical application is associated with undesired therapeutic effects on normal or healthy tissues. The use of targeted agents that can simultaneously achieve therapeutic and imaging functions could constitute a potential solution. Herein, we developed 2-deoxy-d-glucose (2DG)-labeled poly(ethylene glycol) (PEG) gold nanodots (2DG-PEG-AuD) as a tumor-targeted computed tomography (CT) contrast agent and radiosensitizer. The key advantages of the design are its biocompatibility and targeted AuD with excellent sensitivity in tumor detection via avid glucose metabolism. As a consequence, CT imaging with enhanced sensitivity and remarkable radiotherapeutic efficacy could be attained. Our synthesized AuD displayed linear enhancement of CT contrast as a function of its concentration. In addition, 2DG-PEG-AuD successfully demonstrated significant augmentation of CT contrast in both in vitro cell studies and in vivo tumor-bearing mouse models. In tumor-bearing mice, 2DG-PEG-AuD showed excellent radiosensitizing functions after intravenous injection. Results from this work indicate that 2DG-PEG-AuD could greatly potentiate theranostic capabilities by providing high-resolution anatomical and functional images in a single CT scan and therapeutic capability.

Computed tomography of hyper-attenuated liver: Pictorial essay

Demonstration of a very dense or hyper-attenuated liver on the pre-contrast CT images of the abdomen can be an unexpected finding. It may present as a diagnostic challenge if the underlying cause of it is not apparent from the provided clinical history. There are about 12 different pathologic conditions that are associated with deposition of radiopaque elements within the hepatic parenchyma, resulting in diffuse or multi-lobar hyperdense appearance of the liver on abdominal radiographs and CT. Most of them are drug-induced or iatrogenic in nature, while others are the sequelae of genetic disorders like thalassemia, Wilson's disease, and primary hemochromatosis. This pictorial essay will present the CT appearance and etiology of hyper-attenuated liver in various clinical entities.

Monte Carlo simulation of gold nanoparticles for X-ray enhancement application

BACKGROUND

Gold nanoparticles (Au NPs) are regarded as potential agents that enhance the radiosensitivity of tumor cells for theranostic applications. To elucidate the biological mechanisms of radiation dose enhancement effects of Au NPs as well as DNA damage attributable to the inclusion of Au NPs, Monte Carlo (MC) simulations have been deployed in a number of studies.

SCOPE OF REVIEW

This review paper concisely collates and reviews the information reported in the simulation research in terms of MC simulation of radiosensitization and dose enhancement effects caused by the inclusion of Au NPs in tumor cells, simulation mechanisms, benefits and limitations.

MAJOR CONCLUSIONS

In this review, we first explore the recent advances in MC simulation on Au NPs radiosensitization. The MC methods, physical dose enhancement and enhanced chemical and biological effects is discussed, followed by some results regarding the prediction of dose enhancement. We then review Multi-scale MC simulations of Au NP-induced DNA damages for X-ray irradiation. Moreover, we explain and look at Multi-scale MC simulations of Au NP-induced DNA damages for X-ray irradiation.

GENERAL SIGNIFICANCE

Using advanced chemical module-implemented MC simulations, there is a need to assess the radiation-induced chemical radicals that contribute to the dose-enhancing and biological effects of multiple Au NPs.

Revealing the complexity of ultra-soft hydrogel re-swelling inside the brain

The brain is an ultra-soft viscoelastic matrix. Sub-kPa hydrogels match the brain's mechanical properties but are challenging to manipulate in an implantable format. We propose a simple fabrication and processing sequence, consisting of de-hydration, patterning, implantation, and re-hydration steps, to deliver brain-like hydrogel implants into the nervous tissue. We monitored in real-time the ultra-soft hydrogel re-swelling kinetics in vivo using microcomputed tomography, achieved by embedding gold nanoparticles inside the hydrogel for contrast enhancement. We found that re-swelling in vivo strongly depends on the implant geometry and water availability at the hydrogel-tissue interface. Buckling of the implant inside the brain occurs when the soft implant is tethered to the cranium. Finite-element and analytical models reveal how the shank geometry, modulus and anchoring govern in vivo buckling. Taken together, these considerations on re-swelling kinetics of hydrogel constructs, implant geometry and soft implant-tissue mechanical interplay can guide the engineering of biomimetic brain implants.

Green room temperature synthesis of silver-gold alloy nanoparticles

Metallic alloy nanoparticles (NPs) exhibit interesting optical, electrical and catalytic properties, dependent on their size, shape and composition. In particular, silver-gold alloy NPs are widely applied as model systems to better understand the syntheses and formation (kinetics) of alloy NPs, as the two elements are fully miscible. Our study targets product design via environmentally friendly synthesis conditions. We use dextran as the reducing and stabilizing agent for the synthesis of homogeneous silver-gold alloy NPs at room temperature. Our approach is a one-pot, low temperature, reaction-controlled, green and scalable synthesis route of well-controlled composition and narrow particle size distribution. The composition over a broad range of molar gold contents is confirmed by scanning transmission electron microscopy-energy-dispersive X-ray spectroscopy (STEM-EDX) measurements and auxiliary inductively coupled plasma-optical emission spectroscopy measurements (ICP-OES). The distributions of the resulting particles in size and composition are obtained from multi-wavelength analytical ultracentrifugation using the optical back coupling method and further confirmed by high-pressure liquid chromatography. Finally, we provide insight into the reaction kinetics during the synthesis, discuss the reaction mechanism and demonstrate possibilities for scale-up by a factor of more than 250 by increasing the reactor volume and NP concentration.

The Usefulness of Nanotechnology in Improving the Prognosis of Lung Cancer

Lung cancer remains a major public health problem both in terms of incidence and specific mortality despite recent developments in terms of prevention, such as smoking reduction policies and clinical management advances. Better lung cancer prognosis could be achieved by early and accurate diagnosis and improved therapeutic interventions. Nanotechnology is a dynamic and fast-developing field; various medical applications have been developed and deployed, and more exist as proofs of concepts or experimental models. We aim to summarize current knowledge relevant to the use of nanotechnology in lung cancer management. Starting from the chemical structure-based classification of nanoparticles, we identify and review various practical implementations roughly organized as diagnostic or therapeutic in scope, ranging from innovative contrast agents to targeted drug carriers. Available data are presented starting with standards of practice and moving to highly experimental methods and proofs of concept; particularities, advantages, limits and future directions are explored, focusing on the potential impact on lung cancer clinical prognosis.

Application of Gold Nanoparticles as Radiosensitizer for Metastatic Prostate Cancer Cell Lines

More than 50% of all prostate cancer (PCa) patients are treated by radiotherapy (RT). Radioresistance and cancer recurrence are two consequences of the therapy and are related to dose heterogeneity and non-selectivity between normal and tumoral cells. Gold nanoparticles (AuNPs) could be used as potential radiosensitizers to overcome these therapeutic limitations of RT. This study assessed the biological interaction of different morphologies of AuNPs with ionizing radiation (IR) in PCa cells. To achieve that aim, three different amine-pegylated AuNPs were synthesized with distinct sizes and shapes (spherical, AuNP_sp-PEG, star, AuNP_st-PEG, and rods, AuNP_r-PEG) and viability, injury and colony assays were used to analyze their biological effect on PCa cells (PC3, DU145, and LNCaP) when submitted to the accumulative fraction of RT. The combinatory effect of AuNPs with IR decreased cell viability and increased apoptosis compared to cells treated only with IR or untreated cells. Additionally, our results showed an increase in the sensitization enhancement ratio by cells treated with AuNPs and IR, and this effect is cell line dependent. Our findings support that the design of AuNPs modulated their cellular behavior and suggested that AuNPs could improve the RT efficacy in PCa cells.

Evaluating Hydroxyapatite, Gold Nanoparticles, and Graphene-Copper as Bimodal Agents for X-ray and Computed Tomography

A global need exists for new and more effective contrast agents for computed tomography and traditional X-ray modalities. Among the few options available nowadays, limitations imposed by industrial production, performance, and efficacy restrict the use and reduce the potential of both imaging techniques. The use of nanomaterials as new contrast agents for X-ray and computed tomography is an innovative and viable way to increase the options and enhance performance. In this study, we evaluated eight nanomaterials: hydroxyapatite doped with zinc (Zn-HA 10%); hydroxyapatite doped with strontium (Sr-HA 10%); hydroxyapatite without thermal treatment (HA 282 STT); thermally treated hydroxyapatite (HA 212 500 °C and HA 01.256 CTT 1000 °C); hydroxyapatite microspheres (HA microspheres); gold nanoparticles (AuNP); and graphene oxide doped with copper (Cu-GO). The results showed that for both imaging modalities; HA microspheres were the best option, followed by hydroxyapatite thermally treated at 1000 °C. The nanomaterials with the worst results were hydroxyapatite doped with zinc (Zn-HA 10%), and hydroxyapatite doped with strontium (Sr-HA 10%). Our data demonstrated the potential of using nanomaterials, especially HA microspheres, and hydroxyapatite with thermal treatment (HA 01.256 CTT 1000 °C) as contrast agents for X-ray and computed tomography.

Nanotherapeutic and Stem Cell Therapeutic Strategies in Neurodegenerative Diseases: A Promising Therapeutic Approach

Neurodegeneration is characterized by progressive, disabling, and incurable neurological disorders with the massive loss of specific neurons. As one of the most promising potential therapeutic strategies for neurodegenerative diseases, stem cell therapy exerts beneficial effects through different mechanisms, such as direct replacement of damaged or lost cells, secretion of neurotrophic and growth factors, decreased neuroinflammation, and activation of endogenous stem cells. However, poor survival and differentiation rates of transplanted stem cells, insufficient homing ability, and difficulty tracking after transplantation limit their further clinical use. The rapid development of nanotechnology provides many promising nanomaterials for biomedical applications, which already have many applications in neurodegenerative disease treatment and seem to be able to compensate for some of the deficiencies in stem cell therapy, such as transport of stem cells/genes/drugs, regulating stem cell differentiation, and real-time tracking in stem cell therapy. Therefore, nanotherapeutic strategies combined with stem cell therapy is a promising therapeutic approach to treating neurodegenerative diseases. The present review systematically summarizes recent advances in stem cell therapeutics and nanotherapeutic strategies and highlights how they can be combined to improve therapeutic efficacy for the treatment of neurodegenerative diseases.

Nanotechnology-based approaches overcome lung cancer drug resistance through diagnosis and treatment

Lung cancer continues to be a malignant tumor with high mortality. Two obstacles interfere with curative therapy of lung cancer: (i) poor diagnosis at the early stages, as symptoms are not specific or asymptomatic; and (ii) invariably emerging drug resistance after treatment. Some factors contributing to drug resistance include preexisting genetic/genomic drug-resistant alteration(s); activation of adaptive drug resistance pathways; remodeling of the tumor microenvironment; and pharmacological mechanisms or activation of drug efflux pumps. Despite the mechanisms explored to better understand drug resistance, a gap remains between molecular understanding and clinical application. Therefore, facilitating the translation of basic science into the clinical setting is a great challenge. Nanomedicine has emerged as a promising tool for cancer treatment. Because of their excellent physicochemical properties and enhanced permeability and retention effects, nanoparticles have great potential to revolutionize conventional lung cancer diagnosis and combat drug resistance. Nanoplatforms can be designed as carriers to improve treatment efficacy and deliver multiple drugs in one system, facilitating combination treatment to overcome drug resistance. In this review, we describe the difficulties in lung cancer treatment and review recent research progress on nanoplatforms aimed at early diagnosis and lung cancer treatment. Finally, future perspectives and challenges of nanomedicine are also discussed.

Three-Dimensional Spheroids for Cancer Research

In vitro cell culture is one of the most widely used tools used today for increasing our understanding of various things such as protein production, mechanisms of drug action, tissue engineering, and overall cellular biology. For the past decades, however, cancer researchers have relied heavily on conventional two-dimensional (2D) monolayer culture techniques to test a variety of aspects of cancer research ranging from the cytotoxic effects of antitumor drugs to the toxicity of diagnostic dyes and contact tracers. However, many promising cancer therapies have either weak or no efficacy in real-life conditions, therefore delaying or stopping altogether their translating to the clinic. This is, in part, due to the reductionist 2D cultures used to test these materials, which lack appropriate cell-cell contacts, have altered signaling, do not represent the natural tumor microenvironment, and have different drug responses, due to their reduced malignant phenotype when compared to real in vivo tumors. With the most recent advances, cancer research has moved into 3D biological investigation. Three-dimensional (3D) cultures of cancer cells not only recapitulate the in vivo environment better than their 2D counterparts, but they have, in recent years, emerged as a relatively low-cost and scientifically accurate methodology for studying cancer. In this chapter, we highlight the importance of 3D culture, specifically 3D spheroid culture, reviewing some key methodologies for forming 3D spheroids, discussing the experimental tools that can be used in conjunction with 3D spheroids and finally their applications in cancer research.

Clinical translation of gold nanoparticles

Gold nanoparticles display unique physicochemical features, which can be useful for therapeutic purposes. After two decades of preclinical progress, gold nanoconstructs are slowly but steadily transitioning into clinical trials. Although initially thought to be "magic golden bullets" that could be used to treat a wide range of diseases, current consensus has moved toward a more realistic approach, where gold nanoformulations are being investigated to treat specific disorders. These therapeutic applications are dictated by the pharmacokinetics and biodistribution profiles of gold nanoparticles. Here, we analyze the current clinical landscape of therapeutic gold nanoconstructs, discuss the shared characteristics that allowed for their transition from bench to bedside, and examine existing hurdles that need to be overcome before they can be approved for clinical use.

Engineering gold nanoparticles for molecular diagnostics and biosensing

Advances in nanotechnology and medical science have spurred the development of engineered nanomaterials and nanoparticles with particular focus on their applications in biomedicine. In particular, gold nanoparticles (AuNPs) have been the focus of great interest, due to their exquisite intrinsic properties, such as ease of synthesis and surface functionalization, tunable size and shape, lack of acute toxicity and favorable optical, electronic, and physicochemical features, which possess great value for application in biodetection and diagnostics purposes, including molecular sensing, photoimaging, and application under the form of portable and simple biosensors (e.g., lateral flow immunoassays that have been extensively exploited during the current COVID-19 pandemic). We shall discuss the main properties of AuNPs, their synthesis and conjugation to biorecognition moieties, and the current trends in sensing and detection in biomedicine and diagnostics. This article is categorized under: Diagnostic Tools > Biosensing Diagnostic Tools > In Vitro Nanoparticle-Based Sensing Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

In vivo micro-computed tomography imaging in liver tumor study of mice using Fenestra VC and Fenestra HDVC

Contrast agents are used to enhance the visibility of rodent organs during in vivo micro-computed tomography imaging. Specifically, this non-invasive technique can study liver tumor growth and progression in small animals. Fenestra VC and the novel Fenestra HDVC were compared for enhancement in the liver of healthy and tumor-bearing mice, and the images were compared for their ability to define the tumor border, volume and quantity of tumors. Fenestra VC and Fenestra HDVC were injected into healthy eight-week-old female mice (C57BL/6) via the tail vein then imaged at seven different time points. The experimental results showed that 0.005 mL/g of Fenestra HDVC resulted in the same enhancement for all eight organs as 0.01 mL/g of Fenestra VC across all time points. For the tumor study, B16F10 tumors were surgically introduced into ten eight-week-old female mice (C57BL/6) then imaged in vivo over a 3 day period. Ex vivo micro-CT images of the excised livers were also obtained. The tumor volume and quantity were measured in each image, and the tumour progression observed over 3 days. We showed Fenestra HDVC is effective for in vivo imaging in rodents because the optimal enhancement level in organs is maintained at a reduced injection volume.

Biodistribution of Multimodal Gold Nanoclusters Designed for Photoluminescence-SPECT/CT Imaging and Diagnostic

Highly biocompatible nanostructures for multimodality imaging are critical for clinical diagnostics improvements in the future. Combining optical imaging with other techniques may lead to important advances in diagnostics. The purpose of such a system would be to combine the individual advantages of each imaging method to provide reliable and accurate information at the site of the disease bypassing the limitations of each. The aim of the presented study was to evaluate biodistribution of the biocompatible technetium-99m labelled bovine serum albumin-gold nanoclusters (^99mTc-BSA-Au NCs) as photoluminescence-SPECT/CT agent in experimental animals. It was verified spectroscopically that radiolabelling with ^99mTc does not influence the optical properties of BSA-Au NCs within the synthesized ^99mTc-BSA-Au NCs bioconjugates. Biodistribution imaging of the ^99mTc-BSA-Au NCs in Wistar rats was performed using a clinical SPECT/CT system. In vivo imaging of Wistar rats demonstrated intense cardiac blood pool activity, as well as rapid blood clearance and accumulation in the kidneys, liver, and urinary bladder. Confocal images of kidney, liver and spleen tissues revealed no visible uptake indicating that the circulation lifetime of ^99mTc-BSA-Au NCs in the bloodstream might be too short for accumulation in these tissues. The cellular uptake of ^99mTc-BSA-Au NCs in kidney cells was also delayed and substantial accumulation was observed only after 24-h incubation. Based on our experiments, it was concluded that ^99mTc-BSA-Au NCs could be used as a contrast agent and shows promise as potential diagnostic agents for bloodstream imaging of the excretory organs in vivo.

Overcoming the blood–brain barrier for the therapy of malignant brain tumor: current status and prospects of drug delivery approaches

Besides the broad development of nanotechnological approaches for cancer diagnosis and therapy, currently, there is no significant progress in the treatment of different types of brain tumors. Therapeutic molecules crossing the blood–brain barrier (BBB) and reaching an appropriate targeting ability remain the key challenges. Many invasive and non-invasive methods, and various types of nanocarriers and their hybrids have been widely explored for brain tumor treatment. However, unfortunately, no crucial clinical translations were observed to date. In particular, chemotherapy and surgery remain the main methods for the therapy of brain tumors. Exploring the mechanisms of the BBB penetration in detail and investigating advanced drug delivery platforms are the key factors that could bring us closer to understanding the development of effective therapy against brain tumors. In this review, we discuss the most relevant aspects of the BBB penetration mechanisms, observing both invasive and non-invasive methods of drug delivery. We also review the recent progress in the development of functional drug delivery platforms, from viruses to cell-based vehicles, for brain tumor therapy. The destructive potential of chemotherapeutic drugs delivered to the brain tumor is also considered. This review then summarizes the existing challenges and future prospects in the use of drug delivery platforms for the treatment of brain tumors.

Physically stimulus-responsive nanoparticles for therapy and diagnosis

Nanoparticles offer numerous advantages in various fields of science, particularly in medicine. Over recent years, the use of nanoparticles in disease diagnosis and treatments has increased dramatically by the development of stimuli-responsive nano-systems, which can respond to internal or external stimuli. In the last 10 years, many preclinical studies were performed on physically triggered nano-systems to develop and optimize stable, precise, and selective therapeutic or diagnostic agents. In this regard, the systems must meet the requirements of efficacy, toxicity, pharmacokinetics, and safety before clinical investigation. Several undesired aspects need to be addressed to successfully translate these physical stimuli-responsive nano-systems, as biomaterials, into clinical practice. These have to be commonly taken into account when developing physically triggered systems; thus, also applicable for nano-systems based on nanomaterials. This review focuses on physically triggered nano-systems (PTNSs), with diagnostic or therapeutic and theranostic applications. Several types of physically triggered nano-systems based on polymeric micelles and hydrogels, mesoporous silica, and magnets are reviewed and discussed in various aspects.

Metal-Polymer Nanoconjugates Application in Cancer Imaging and Therapy

Metallic-based nanoparticles present a unique set of physicochemical properties that support their application in different fields, such as electronics, medical diagnostics, and therapeutics. Particularly, in cancer therapy, the plasmonic resonance, magnetic behavior, X-ray attenuation, and radical oxygen species generation capacity displayed by metallic nanoparticles make them highly promising theragnostic solutions. Nevertheless, metallic-based nanoparticles are often associated with some toxicological issues, lack of colloidal stability, and establishment of off-target interactions. Therefore, researchers have been exploiting the combination of metallic nanoparticles with other materials, inorganic (e.g., silica) and/or organic (e.g., polymers). In terms of biological performance, metal-polymer conjugation can be advantageous for improving biocompatibility, colloidal stability, and tumor specificity. In this review, the application of metallic-polymer nanoconjugates/nanohybrids as a multifunctional all-in-one solution for cancer therapy will be summarized, focusing on the physicochemical properties that make metallic nanomaterials capable of acting as imaging and/or therapeutic agents. Then, an overview of the main advantages of metal-polymer conjugation as well as the most common structural arrangements will be provided. Moreover, the application of metallic-polymer nanoconjugates/nanohybrids made of gold, iron, copper, and other metals in cancer therapy will be discussed, in addition to an outlook of the current solution in clinical trials.

New strategies towards advanced CT contrast agents. Development of neutral and monoanionic sulfur-bridged W(V) dimeric complexes

Multinuclear tungsten complexes are intriguing candidates for new contrast media that can provide substantial improvements in CT imaging diagnostics. Herein, we present a ligand strategy, based on amino acids, and mono- and disubstituted EDTA derivatives, that enables the development of stable complexes with high tungsten content and reasonably low osmolality. Accordingly, a series of neutral and monoanionic di-μ-sulfido W(V) dimers have been synthesized via a convenient procedure utilizing microwave heating in combination with ion-pair HPLC reaction monitoring. The compounds were characterized in detail by various techniques, including ESI-HRMS, NMR spectroscopy, HPLC, elemental analysis, and X-ray crystallography. The aqueous stability of the complexes under physiologically relevant conditions, and during heat sterilization was also examined as an initial assessment of their potential applicability as radiocontrast agents. Monoanionic complexes featuring monosubstituted EDTA derivatives have demonstrated high stability, while producing a lower number of ions in solution (resulting in lower osmolality) in comparison to their bis-anionic EDTA counterparts. Nevertheless, they exhibited insufficient water solubility for application as intravascular contrast agents. However, our study showed that aqueous solubility of this type of complexes can be tuned by small modifications in the ligand structure.

"Plasmonic Nanomaterials": An emerging avenue in biomedical and biomedical engineering opportunities

BACKGROUND

Plasmonic nanomaterials asnoble metal-based materials have unique optical characteristic upon exposure to incident light with an appropriate wavelength. Today, generated plasmon by nanoparticles has receivedincreasingattention in nanomedicine; from diagnosis, tissue and tumor imaging to therapeutic and biomedical engineering.

AIM OF REVIEW

Due to rapid growing of knowledge in the inorganic nanomaterial field, this paper aims to be a comprehensive and authoritative, critical, and broad interest to the scientific community. Here, we introduce basic physicochemical properties of plasmonic nanoparticles and their applications in biomedical and tissue engineering The first part of each division explain the basic physico-chemical properties of each nanomaterial with a graphical abstract. In the second part, concepts by describing classic examples taken from the biomedical and biomedical engineering literature are illustrated. The selected case studies are intended to give an overview of the different systems and mechanisms utilized in nanomedicine.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this communication, we have tried to introduce the needed concepts of plasmonic nanomaterials and their implication in a particular part of biomedical over the last 20 years. Moreover, in each part with insist on limitations, a perspective is presented which can guide a researcher how they can develop or modify new scaffolds for biomedical engineering.

Prospecting Cellular Gold Nanoparticle Biomineralization as a Viable Alternative to Prefabricated Gold Nanoparticles

Gold nanoparticles (GNPs) have shown considerable potential in a vast number of biomedical applications. However, currently there are no clinically approved injectable GNP formulations. Conversely, gold salts have been used in the clinic for nearly a century. Further, there is evidence of GNP formation in patients treated with gold salts (i.e., chrysiasis). Recent reports evaluating this phenomenon in human cells and in murine models indicate that the use of gold ions for in situ formation of theranostic GNPs could greatly improve the delivery within dense biological tissues, increase efficiency of intracellular gold uptake, and specificity of GNP formation within cancer cells. These attributes in combination with safe clinical application of gold salts make this process a viable strategy for clinical translation. Here, the first summary of the current knowledge related to GNP biomineralization in mammalian cells is provided along with critical assessment of potential biomedical applications of this newly emergent field.

Green synthesis of gold nanoparticles in Gum Arabic using pulsed laser ablation for CT imaging

Laser ablation synthesis in liquid solution (PLAL) is a green technique that allows for the physical formation of nanomaterials. This study indicates the preparation of stable gold nanoparticles (AuNPs) in Gum Arabic (GA) solution via laser ablation as a CT contrast agent. The optical properties were achieved using the absorption spectroscopic technique whereas the morphology and size distribution were investigated by TEM and ImageJ software. TEM image shows greater stability and spherical shape of GA-AuNPs with smaller size at 1.85 ± 0.99 nm compared to AuNPs without GA. The absorption spectrum of pure AuNPs has a lower absorption peak height in the visible range at λ = 521 nm, while the spectrum of GA-AuNPs has a higher plasmon peak height at λ = 514 nm with a blue shift towards lower wavelengths. The concentration of GA that dissolved in 10 mL of DI water via laser ablation is set at 20 mg. Increasing the number of pulses has only a minor effect on particle size distribution, which remains tiny in the nanometer range (less than 3 nm). For energies greater than 200 mJ, there is a blue shift toward shorter wavelengths. As the concentration of GA-AuNPs increases, the CT number is also increased indicating good image contrast. It can be concluded that there is a positive and significant influence of GA as a reducing agent for AuNPs, and a contrast agent for CT imaging which highlights its superiority in future medical applications.

Clinical Feasibility Study of Gold Nanoparticles as Theragnostic Agents for Precision Radiotherapy

Background: Gold nanoparticles (AuNP) may be useful in precision radiotherapy and disease monitoring as theragnostic agents. In diagnostics, they can be detected by computerized tomography (CT) because of their higher atomic number. AuNP may also improve the treatment results in radiotherapy due to a higher cross-section, locally improving the physically absorbed dose. Methods: Key parameters values involved in the use of AuNP were imposed to be optimal in the clinical scenario. Mass concentration of AuNP as an efficient contrast agent in clinical CT was found and implemented in a Monte Carlo simulation method for dose calculation under different proposed therapeutic beams. The radiosensitization effect was determined in irradiated cells with AuNP. Results: an AuNP concentration was found for a proper contrast level and enhanced therapeutic effect under a beam typically used for image-guided therapy and monitoring. This lower energetic proposed beam showed potential use for treatment monitoring in addition to absorbed dose enhancement and higher radiosensitization at the cellular level. Conclusion: the results obtained show the use of AuNP concentration around 20 mg Au·mL⁻¹ as an efficient tool for diagnosis, treatment planning, and monitoring treatment. Simultaneously, the delivered prescription dose provides a higher radiobiological effect on the cancer cell for achieving precision radiotherapy.

Treasure on the Earth—Gold Nanoparticles and Their Biomedical Applications

Recent advances in the synthesis of metal nanoparticles (NPs) have led to tremendous expansion of their potential applications in different fields, ranging from healthcare research to microelectronics and food packaging. Among the approaches for exploiting nanotechnology in medicine, gold nanomaterials in particular have been found as the most promising due to their unique advantages, such as in sensing, image enhancement, and as delivery agents. Although, the first scientific article on gold nanoparticles was presented in 1857 by Faraday, during the last few years, the progress in manufacturing these nanomaterials has taken an enormous step forward. Due to the nanoscale counterparts of gold, which exhibit distinct properties and functionality compared to bulk material, gold nanoparticles stand out, in particular, in therapy, imaging, detection, diagnostics, and precise drug delivery. This review summarizes the current state-of-the-art knowledge in terms of biomedical applications of gold nanoparticles. The application of AuNPs in the following aspects are discussed: (i) imaging and diagnosing of specific target; (ii) treatment and therapies using AuNPs; and (iii) drug delivery systems with gold nanomaterials as a carrier. Among the different approaches in medical imaging, here we either consider AuNPs as a contrast agent in computed tomography (CT), or as a particle used in optical imaging, instead of fluorophores. Moreover, their nontoxic feature, compared to the gadolinium-based contrast agents used in magnetic resonance imaging, are shown. The tunable size, shape, and functionality of gold nanoparticles make them great carriers for targeted delivery. Therefore, here, we summarize gold-based nanodrugs that are FDA approved. Finally, various approaches to treat the specific diseases using AuNPs are discussed, i.e., photothermal or photodynamic therapy, and immunotherapy.

Comparative X-ray Shielding Properties of Single-Layered and Multi-Layered Bi2O3/NR Composites: Simulation and Numerical Studies

This work theoretically compared the X-ray attenuation capabilities in natural rubber (NR) composites containing bismuth oxide (Bi₂O₃) by determining the effects of multi-layered structures on the shielding properties of the composites using two different software packages (XCOM and PHITS). The shielding properties of the single-layered and multi-layered Bi₂O₃/NR composites investigated consisted of the transmission factor (I/I₀), effective linear attenuation coefficient (µ_eff), effective mass attenuation coefficient (µ_m,eff), and effective half-value layer (HVL_eff). The results, with good agreement between those obtained from XCOM and PHITS (with less than 5% differences), indicated that the three-layered NR composites (sample#4), with the layer arrangement of pristine NR (layer#1)-Bi₂O₃/NR (layer#2)-pristine NR (layer#3), had relatively higher X-ray shielding properties than either a single-layer or the other multi-layered structures for all X-ray energies investigated (50, 100, 150, and 200 keV) due to its relatively larger effective percentage by weight of Bi₂O₃ in the composites. Furthermore, by varying the Bi₂O₃ contents in the middle layer (layer#2) of sample#4 from 10 to 90 wt.%, the results revealed that the overall X-ray shielding properties of the NR composites were further enhanced with additional filler, as evidenced by the highest values of µ_eff and µ_m,eff and the lowest values of I/I₀ and HVL_eff observed in the 90 wt.% Bi₂O₃/NR composites. In addition, the recommended Bi₂O₃ contents for the actual production of three-layered Bi₂O₃/NR composites (the same layer structure as sample#4) were determined by finding the least Bi₂O₃ content that enabled the sample to attenuate incident X-rays with equal efficiency to that of a 0.5-mm lead sheet (with an effective lead equivalence of 0.5 mmPb). The results suggested that the recommended Bi₂O₃ contents in layer#2 were 82, 72, and 64 wt.% for the combined 6 mm, 9 mm, and 12 mm samples, respectively.

Unique Properties of Surface-Functionalized Nanoparticles for Bio-Application: Functionalization Mechanisms and Importance in Application

This review tries to summarize the purpose of steadily developing surface-functionalized nanoparticles for various bio-applications and represents a fascinating and rapidly growing field of research. Due to their unique properties-such as novel optical, biodegradable, low-toxicity, biocompatibility, size, and highly catalytic features-these materials are considered superior, and it is thus vital to study these systems in a realistic and meaningful way. However, rapid aggregation, oxidation, and other problems are encountered with functionalized nanoparticles, inhibiting their subsequent utilization. Adequate surface modification of nanoparticles with organic and inorganic compounds results in improved physicochemical properties which can overcome these barriers. This review investigates and discusses the iron oxide nanoparticles, gold nanoparticles, platinum nanoparticles, silver nanoparticles, and silica-coated nanoparticles and how their unique properties after fabrication allow for their potential use in a wide range of bio-applications such as nano-based imaging, gene delivery, drug loading, and immunoassays. The different groups of nanoparticles and the advantages of surface functionalization and their applications are highlighted here. In recent years, surface-functionalized nanoparticles have become important materials for a broad range of bio-applications.

Blood Plasma Stabilized Gold Nanoclusters for Personalized Tumor Theranostics

Simple Summary

Cancer is a disease that has a high fatality rate over the world. Nanotechnology is one of the most promising current approaches for developing novel diagnostic and treatment methods in accomplishing more personalized medicine. Personalized gold nanoclusters have potential to be used in cancer theranostics. We demonstrate that biocompatible gold nanoclusters could be synthesized directly in human blood plasma. Such gold nanoclusters have a wide photoluminescence band in the optical tissue window and generate reactive oxygen species under irradiation with visible light, thus are suitable for cancer theranostics.

Abstract

Personalized cancer theranostics has a potential to increase efficiency of early cancer diagnostics and treatment, and to reduce negative side-effects. Protein-stabilized gold nanoclusters may serve as theranostic agents. To make gold nanoclusters personalized and highly biocompatible, the clusters were stabilized with human plasma proteins. Optical properties of synthesized nanoclusters were investigated spectroscopically, and possible biomedical application was evaluated using standard cell biology methods. The spectroscopic investigations of human plasma proteins stabilized gold nanoclusters revealed that a wide photoluminescence band in the optical tissue window is suitable for cancer diagnostics. High-capacity generation of singlet oxygen and other reactive oxygen species was also observed. Furthermore, the cluster accumulation in cancer cells and the photodynamic effect were evaluated. The results demonstrate that plasma proteins stabilized gold nanoclusters that accumulate in breast cancer cells and are non-toxic in the dark, while appear phototoxic under irradiation with visible light. The results positively confirm the utility of plasma protein stabilized gold nanoclusters for the use in cancer diagnostics and treatment.

Gold nanostructures: synthesis, properties, and neurological applications

Recent advances in technology are expected to increase our current understanding of neuroscience. Nanotechnology and nanomaterials can alter and control neural functionality in both in vitro and in vivo experimental setups. The intersection between neuroscience and nanoscience may generate long-term neural interfaces adapted at the molecular level. Owing to their intrinsic physicochemical characteristics, gold nanostructures (GNSs) have received much attention in neuroscience, especially for combined diagnostic and therapeutic (theragnostic) purposes. GNSs have been successfully employed to stimulate and monitor neurophysiological signals. Hence, GNSs could provide a promising solution for the regeneration and recovery of neural tissue, novel neuroprotective strategies, and integrated implantable materials. This review covers the broad range of neurological applications of GNS-based materials to improve clinical diagnosis and therapy. Sub-topics include neurotoxicity, targeted delivery of therapeutics to the central nervous system (CNS), neurochemical sensing, neuromodulation, neuroimaging, neurotherapy, tissue engineering, and neural regeneration. It focuses on core concepts of GNSs in neurology, to circumvent the limitations and significant obstacles of innovative approaches in neurobiology and neurochemistry, including theragnostics. We will discuss recent advances in the use of GNSs to overcome current bottlenecks and tackle technical and conceptual challenges.

Recent advances and applications of microspheres and nanoparticles in transarterial chemoembolization for hepatocellular carcinoma

Transarterial chemoembolization (TACE) is a recommended treatment for patients suffering from intermediate and advanced hepatocellular carcinoma (HCC). As compared to the conventional TACE, drug-eluting bead TACE demonstrates several advantages in terms of survival, treatment response, and adverse effects. The selection of embolic agents is critical to the success of TACE. Many studies have been performed on the modification of the structure, size, homogeneity, biocompatibility, and biodegradability of embolic agents. Continuing efforts are focused on efficient loading of versatile chemotherapeutics, controlled sizes for sufficient occlusion, real-time detection intra- and post-procedure, and multimodality imaging-guided precise treatment. Here, we summarize recent advances and applications of microspheres and nanoparticles in TACE for HCC. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.