Gold nanoshelled liquid perfluorocarbon nanocapsules for combined dual modal ultrasound/CT imaging and photothermal therapy of cancer

Using anti-PD-L1 antibody conjugated gold nanoshelled poly (Lactic-co-glycolic acid) nanocapsules loaded with doxorubicin: A theranostic agent for ultrasound imaging and photothermal/chemo combination therapy of triple negative breast cancer

Triple negative breast cancer (TNBC) has the worst prognosis of all breast cancers, and it is difficult to progress through traditional chemotherapy. Therefore, the treatment of TNBC urgently requires agents with effective diagnostic and therapeutic capabilities. In this study, we obtained programmed death-ligand 1 (PD-L1) antibody conjugated gold nanoshelled poly(lactic-co-glycolic acid) (PLGA) nanocapsules (NCs) encapsulating doxorubicin (DOX) (DOX@PLGA@Au-PD-L1 NCs). PLGA NCs encapsulating DOX were prepared by a modified single-emulsion oil-in-water (O/W) solvent evaporation method, and gold nanoshells were formed on the surface by gold seed growth method, which were coupled with PD-L1 antibodies by carbodiimide method. The fabricated DOX@PLGA@Au-PD-L1 NCs exhibited promising contrast enhancement in vitro ultrasound imaging. Furthermore, DOX encapsulated in NCs displayed good pH-responsive and photo-triggered drug release properties. After irradiating 200 μg/mL NCs solution with a laser for 10 min, the solution temperature increased by nearly 23°C, indicating that the NCs had good photothermal conversion ability. The targeting experiments confirmed that the NCs had specific target binding ability to TNBC cells overexpressing PD-L1 molecules. Cell experiments exhibited that the agent significantly reduced the survival rate of TNBC cells through photochemotherapy combination therapy. As a multifunctional diagnostic agent, DOX@PLGA@Au-PD-L1 NCs could be used for ultrasound targeted contrast imaging and photochemotherapy combination therapy of TNBC cells, providing a promising idea for early diagnosis and treatment of TNBC.

Application and prospects of AI-based radiomics in ultrasound diagnosis

Artificial intelligence (AI)-based radiomics has attracted considerable research attention in the field of medical imaging, including ultrasound diagnosis. Ultrasound imaging has unique advantages such as high temporal resolution, low cost, and no radiation exposure. This renders it a preferred imaging modality for several clinical scenarios. This review includes a detailed introduction to imaging modalities, including Brightness-mode ultrasound, color Doppler flow imaging, ultrasound elastography, contrast-enhanced ultrasound, and multi-modal fusion analysis. It provides an overview of the current status and prospects of AI-based radiomics in ultrasound diagnosis, highlighting the application of AI-based radiomics to static ultrasound images, dynamic ultrasound videos, and multi-modal ultrasound fusion analysis.

Perfluorocarbons: A perspective of theranostic applications and challenges

Perfluorocarbon (PFC) are biocompatible compounds, chemically and biologically inert, and lacks toxicity as oxygen carriers. PFCs nanoemulsions and nanoparticles (NPs) are highly used in diagnostic imaging and enable novel imaging technology in clinical imaging modalities to notice and image pathological and physiological alterations. Therapeutics with PFCs such as the innovative approach to preventing thrombus formation, PFC nanodroplets utilized in ultrasonic medication delivery in arthritis, or PFC-based NPs such as Perfluortributylamine (PFTBA), Pentafluorophenyl (PFP), Perfluorohexan (PFH), Perfluorooctyl bromide (PFOB), and others, recently become renowned for oxygenating tumors and enhancing the effects of anticancer treatments as oxygen carriers for tumor hypoxia. In this review, we will discuss the recent advancements that have been made in PFC's applications in theranostic (therapeutics and diagnostics) as well as assess the benefits and drawbacks of these applications.

Recent Studies and Progress in the Intratumoral Administration of Nano-Sized Drug Delivery Systems

Over the last 30 years, diverse types of nano-sized drug delivery systems (nanoDDSs) have been intensively explored for cancer therapy, exploiting their passive tumor targetability with an enhanced permeability and retention effect. However, their systemic administration has aroused some unavoidable complications, including insufficient tumor-targeting efficiency, side effects due to their undesirable biodistribution, and carrier-associated toxicity. In this review, the recent studies and advancements in intratumoral nanoDDS administration are generally summarized. After identifying the factors to be considered to enhance the therapeutic efficacy of intratumoral nanoDDS administration, the experimental results on the application of intratumoral nanoDDS administration to various types of cancer therapies are discussed. Subsequently, the reports on clinical studies of intratumoral nanoDDS administration are addressed in short. Intratumoral nanoDDS administration is proven with its versatility to enhance the tumor-specific accumulation and retention of therapeutic agents for various therapeutic modalities. Specifically, it can improve the efficacy of therapeutic agents with poor bioavailability by increasing their intratumoral concentration, while minimizing the side effect of highly toxic agents by restricting their delivery to normal tissues. Intratumoral administration of nanoDDS is considered to expand its application area due to its potent ability to improve therapeutic effects and relieve the systemic toxicities of nanoDDSs.

Au/Mn nanodot platform for in vivo CT/MRI/FI multimodal bioimaging and photothermal therapy against tongue cancer

Surgical resection is the main method for oral tongue squamous cell carcinoma (OTSCC) treatment. However, the oral physiological function and aesthetics may be seriously damaged during the operation with a high risk of recurrence. Therefore, it is important to develop an alternative strategy with precise guidance for OTSCC treatment. Herein, multifunctional Au/Mn nanodots (NDs) are designed and synthesized. They can perform multimodal bioimaging, including computed tomography (CT) and magnetic resonance imaging (MRI) simultaneously, and exhibit bright near-infrared fluorescence imaging (FI) for navigation, and even integrate photothermal therapy (PTT) property. The localization of OTSCC relies on visual and tactile cues of surgeons while lacking noninvasive pretreament labeling and guidance. Au/Mn NDs provide CT/MRI imaging, giving two means of accurate positioning pretherapy. Meanwhile, the fluorescence of the Au/Mn NDs in the near-infrared region (NIR) is beneficial for noninvasive labeling and intuitive observation with the naked eye to determine the tumor boundary during PTT. Further, Au/Mn NDs showed excellent results in ablating tumors in vivo. Above all, the Au/Mn NDs provide a key platform for multimodal bioimaging and PTT in a single nanoagent, which demonstrated attractive performance for OTSCC treatment.

Tumor immunotherapy boosted by R837 nanocrystals through combining chemotherapy and mild hyperthermia

Melanoma is a malignant skin cancer that is prone to metastasis in the early stage and has a poor prognosis. Immunomodulatory therapy for melanoma has been a hot research topic in recent years. However, low immune cell infiltration and loss of tumor immunogenicity may occur in tumors, resulting in low response rates to immunotherapy. Thus, immunomodulatory therapy is usually used in combination with chemotherapy and radiotherapy. Development of combined therapeutic strategies with low systemic toxicity, high immune responsiveness and long-term inhibition of metastasis and recurrence of melanoma is the goal of current research. In this study, the insoluble immune adjuvant imiquimod (R837) was prepared as nanocrystals and coated with polydopamine (PDA) to form R837@PDA, which was then loaded into chitosan hydrogel (CGP) to form the drug-loaded gel system, R837@PDA@CGP (RPC), to combine immunomodulation effects, induction of immunogenic cell death (ICD) effects and immune-enhancement effects. After treatment with RPC, ICD in melanoma was induced, and the infiltration rate of cytotoxic T cells (CTLs) in melanoma was also significantly enhanced, which turned the tumor itself into an in situ vaccine and boosted the cancer-immunity cycle at the tumor site. Therefore, melanoma growth, metastasis and recurrence were notably inhibited.

How Did Conventional Nanoparticle-Mediated Photothermal Therapy Become "Hot" in Combination with Cancer Immunotherapy?

Simple Summary

Photothermal therapy (PTT) has become effective through the development of nanoparticle-based photoabsorbers with various functions, such as targeting properties, high light-to-heat conversion, and photostability. Conventional nanoparticle-mediated PTT has attained localized efficiency in cancer treatment by heat-induced apoptosis or necrosis of cancer cells. Currently, such treatment methods evolve into cancer immunotherapy through the induction of immunogenic cell death (ICD). Damage-associated molecular patterns from dead cells by nanoparticle-mediated PTT activate immune cells for systemic anti-cancer effect. In this review, we investigate various nanoparticle-based PTT and compare its methodology to clarify how it undergoes a transition from thermotherapy to immunotherapy.

Abstract

One of the promising cancer treatment methods is photothermal therapy (PTT), which has achieved good therapeutic efficiency through nanoparticle-based photoabsorbers. Because of the various functions of nanoparticles, such as targeting properties, high light-to-heat conversion, and photostability, nanoparticle-mediated PTT successfully induces photothermal damage in tumor tissues with minimal side effects on surrounding healthy tissues. The therapeutic efficacy of PTT originates from cell membrane disruption, protein denaturation, and DNA damage by light-induced heat, but these biological impacts only influence localized tumor areas. This conventional nanoparticle-mediated PTT still attracts attention as a novel cancer immunotherapy, because PTT causes immune responses against cancer. PTT-induced immunogenic cell death activates immune cells for systemic anti-cancer effect. Additionally, the excellent compatibility of PTT with other treatment methods (e.g., chemotherapy and immune checkpoint blockade therapy) reinforces the therapeutic efficacy of PTT as combined immunotherapy. In this review, we investigate various PTT agents of nanoparticles and compare their applications to reveal how nanoparticle-mediated PTT undergoes a transition from thermotherapy to immunotherapy.

Ultrasound and nanomaterial: an efficient pair to fight cancer

Ultrasounds are often used in cancer treatment protocols, e.g. to collect tumor tissues in the right location using ultrasound-guided biopsy, to image the region of the tumor using more affordable and easier to use apparatus than MRI and CT, or to ablate tumor tissues using HIFU. The efficacy of these methods can be further improved by combining them with various nano-systems, thus enabling: (i) a better resolution of ultrasound imaging, allowing for example the visualization of angiogenic blood vessels, (ii) the specific tumor targeting of anti-tumor chemotherapeutic drugs or gases attached to or encapsulated in nano-systems and released in a controlled manner in the tumor under ultrasound application, (iii) tumor treatment at tumor site using more moderate heating temperatures than with HIFU. Furthermore, some nano-systems display adjustable sizes, i.e. nanobubbles can grow into micro-bubbles. Such dual size is advantageous since it enables gathering within the same unit the targeting properties of nano bubbles via EPR effect and the enhanced ultrasound contrasting properties of micro bubbles. Interestingly, the way in which nano-systems act against a tumor could in principle also be adjusted by accurately selecting the nano-system among a large choice and by tuning the values of the ultrasound parameters, which can lead, due to their mechanical nature, to specific effects such as cavitation that are usually not observed with purely electromagnetic waves and can potentially help destroying the tumor. This review highlights the clinical potential of these combined treatments that can improve the benefit/risk ratio of current cancer treatments.

Target-Triggered Nanomaterial Self-Assembly Induced Electromagnetic Hot-Spot Generation for SERS-Fluorescence Dual-Mode In Situ Monitoring MiRNA-Guided Phototherapy

A multifunctional theranostic nanosystem that integrates dynamic monitoring and therapeutic functions is necessary for precision tumor medicine. Herein, an entropy-driven self-assembly nanomachine is developed that overcomes the mechanism differences of different diagnostic modes and is applied to miRNA surface-enhanced Raman scattering (SERS)-fluorescence dual-mode dynamic monitoring and synergy phototherapy. It is worth noting that the activated dual-mode theranostic nanosystem (DTN) is capable of tumor in situ fluorescence imaging and SERS absolute quantification of the target. After being internalized into tumor cells, the DTN nanosystem is activated by the DNA cascade chain displacement of the target miR-21, resulting in the secondary release of fluorophores and the assembly of core-satellite structures (CS structures). The coupling of localized surface plasmon resonances (LSPRs) in the CS structure results in the formation of numerous enhanced electric fields (hot spot) in the nanogap of the CS structure. Then the DTN nanosystem greatly improves the sensitivity and repeatability of Raman detection by converting trace targets into numerous adenines residing in the electromagnetic hot spot of the CS structure. Meanwhile, the CS structure and the loaded photosensitizer are used for synergy phototherapy under the guidance of fluorescence imaging. This proposed strategy is confirmed by in vivo and in vitro results, and it provides new ideas for tumor SERS-fluorescence dual-mode diagnosis and effective tumor therapy.

Development and application of ultrasound contrast agents in biomedicine

With the rapid development of molecular imaging, ultrasound (US) medicine has evolved from traditional imaging diagnosis to integrated diagnosis and treatment at the molecular level. Ultrasound contrast agents (UCAs) play a crucial role in the integration of US diagnosis and treatment. As the micro-bubbles (MBs) in UCAs can enhance the cavitation effect and promote the biological effect of US, UCAs have also been studied in the fields of US thrombolysis, mediated gene transfer, drug delivery, and high intensity focused US. The application range of UCAs is expanding, and the value of their applications is improving. This paper reviews the development and application of UCAs in biomedicine in recent years, and the existing problems and prospects are pointed out.

Phototherapy and multimodal imaging of cancers based on perfluorocarbon nanomaterials

Phototherapy, such as photodynamic therapy (PDT) and photothermal therapy (PTT), possesses unique characteristics of non-invasiveness and minimal side effects in cancer treatment, compared with conventional therapies. However, the ubiquitous tumor hypoxia microenvironments could severely reduce the efficacy of oxygen-consuming phototherapies. Perfluorocarbon (PFC) nanomaterials have shown great practical value in carrying and transporting oxygen, which makes them promising agents to overcome tumor hypoxia and extend reactive oxygen species (ROS) lifetime to improve the efficacy of phototherapy. In this review, we summarize the latest advances in PFC-based PDT and PTT, and combined multimodal imaging technologies in various cancer types, aiming to facilitate their application-oriented clinical translation in the future.

Polydopamine-carbon dots functionalized hollow carbon nanoplatform for fluorescence-imaging and photothermal-enhanced thermochemotherapy

The low power photothermal therapy can reduce the tissue damage caused by laser irradiation, thus the near-infrared (NIR) absorbing vehicles with high photothermal conversion efficiency are demanded in the low power treatment. Herein, the NIR-absorbing agent polydopamine (PDA) and carbon dots (CDs) were gated on the openings of hollow mesoporous carbon (HMC) to construct a photothermal enhanced multi-functional system (HMC-SS-PDA@CDs). Interestingly, the fluorescence emission wavelength of HMC-SS-PDA@CDs was red-shifted by FRET effect between PDA and CDs, which solved the dilemma of fluorescence quenching of carbon-based materials and was more conducive to cell imaging. The modification of PDA@CDs not only acts as the gatekeepers to realize multi-responsive release of pH, GSH and NIR, but also endows the HMC vehicle with excellent photothermal generation capacity, the possibility for bio-imaging as well as the enhanced stability. Naturally, both the cytological level and the multicellular tumor sphere level demonstrate that the delivery system has good low-power synergistic therapeutic with combination index (CI) of 0.348 and imaging effects. Meanwhile, the combined treatment group showed the highest tumor inhibition rate of 92.6% at 0.75 W/cm². Therefore, DOX/HMC-SS-PDA@CDs nano-platform had broad application prospects in low power therapy and convenient imaging of carbon-based materials.

Mitochondria targeted nanoparticles to generate oxygen and responsive-release of carbon monoxide for enhanced photogas therapy of cancer

Oxygen generating and photothermally responsive carbon monoxide delivering nanoparticles with a mitochondria-targeting property were developed to enhance a combination of phototherapy and gas therapy.

Mucin-16 targeted mesoporous nano-system for evaluation of cervical cancer via dual-modal computed tomography and ultrasonography

Mesoporous silica-coated bismuth nanoparticles (NPs) are dual-modal contrast agents that enable detection and quantification of cervical cancers at early stages using computed tomography (CT) and ultrasonography (US).

Laser activatable perfluorocarbon bubbles for imaging and therapy through enhanced absorption from coupled silica coated gold nanoparticles

Nanoparticles have extensively been used for cancer therapy and imaging (i.e., theranostics) using various imaging modalities. Due to their physical and chemical properties (e.g., absorption, fluorescence, and magnetic properties) they have been used for image guided therapy for cancer treatment monitoring. There are various limitations that make many theranostic agents unable to be used for the extended periods of time required for enhancing theranostic capabilities. Some of these are due to inherent characteristics (e.g., change and/or breakdown of structure) present upon continuous irradiation and others are due to environmental (i.e., physiological) conditions that can lead to physical instability (i.e., in terms of size) affecting the amount of particles that can accumulate at the target site and the overall contrast that can be achieved. In this study, perfluorohexane (PFH) nanoemulsions (NEs) were synthesized with silica coated gold nanoparticles (PFH-NEs-scAuNPs) in order to give both stable and enhanced signals for cancer imaging by increasing vaporization of the emulsions into bubbles through the process of optical droplet vaporization (ODV). The resulting perfluorohexane bubbles could be imaged using nonlinear ultrasound (NL US) which significantly increases the signal to noise ratio due to the nonlinear scattering properties of oscillating bubbles. The NL US signals from PFH bubbles were found to be more stable compared to conventional bubbles used for contrast imaging. In addition, the vaporization of PFH NEs into bubbles was shown to cause significant cancer cell death reflecting the theranostic capabilities of the formed PFH bubbles. Since cell death is initiated with laser excitation of PFH-NEs-scAuNPs, these nanoparticles can specifically target cancer cells once they have accumulated at the tumor region. Due to the type of theranostic agent and imaging modality used, the PFH-NEs-scAuNPs can be used to provide higher specificity compared to other agents for locating the tumor region by minimizing tissue specific signals while at the same time being used to treat cancer.

PFH-NEs from PFH-NEs-scAuNPs can vaporize upon laser excitation leading to formation of PFH bubbles that can be used for contrast enhanced US imaging and therapy.

Preparation and in vitro study of stromal cell-derived factor 1-targeted Fe3O4/poly(lactic-co-glycolic acid)/perfluorohexane nanoparticles

Compared with traditional imaging techniques, multimodal imaging obtains more accurate images that may increase disease detection rates. The present study prepared stromal cell-derived factor 1 (SDF-1)-loaded, targeted nanoparticles coated with iron (II,III) oxide and perfluorohexane (PFH) to be used as polymer-shelled contrast agents with multimodal imaging functions, with the aim of improving tongue cancer and lymph node metastasis diagnosis. The multifunctional, targeted, polymeric nanoparticles were prepared using a double emulsion method and chemokine SDF-1 was conjugated to nanoparticles by a sulfide bond. The nanoparticles were spherical, uniform size and well dispersed. The results of the in vitro photoacoustic and ultrasonic imaging experiments demonstrated that the multifunctional nanoparticles displayed excellent multimodal imaging functions, as even small concentrations of nanoparticles presented clear ultrasound and photoacoustic imaging. When the temperature reached the boiling point of PFH (56˚C), a liquid-gas phase change occurred and the microsphere volume and acoustic impedance increased, leading to enhanced ultrasonic development. The nanoparticles were automatically targeted to tongue squamous carcinoma cells in vitro via SDF-1-CXC chemokine receptor 4 interactions. The targeted experiment and flow cytometry results indicated that the nanoparticles underwent strong targeted binding to human tongue squamous cell carcinoma (SCC-15) cells. In summary, the nanoparticles were automatically targeted to SCC-15 cells and displayed promising characteristics for ultrasound and photoacoustic imaging. Higher concentrations of nanoparticles was associated with clearer imaged and greater echo intensity value and photoacoustic value. The present study established a foundation for the development of procedures for primary tongue cancer and lymph node metastasis diagnosis.

Smart Gold Nanostructures for Light Mediated Cancer Theranostics: Combining Optical Diagnostics with Photothermal Therapy

Nanotheranostics, which combines optical multiplexed disease detection with therapeutic monitoring in a single modality, has the potential to propel the field of nanomedicine toward genuine personalized medicine. Currently employed mainstream modalities using gold nanoparticles (AuNPs) in diagnosis and treatment are limited by a lack of specificity and potential issues associated with systemic toxicity. Light-mediated nanotheranostics offers a relatively non-invasive alternative for cancer diagnosis and treatment by using AuNPs of specific shapes and sizes that absorb near infrared (NIR) light, inducing plasmon resonance for enhanced tumor detection and generating localized heat for tumor ablation. Over the last decade, significant progress has been made in the field of nanotheranostics, however the main biological and translational barriers to nanotheranostics leading to a new paradigm in anti-cancer nanomedicine stem from the molecular complexities of cancer and an incomplete mechanistic understanding of utilization of Au-NPs in living systems. This work provides a comprehensive overview on the biological, physical and translational barriers facing the development of nanotheranostics. It will also summarise the recent advances in engineering specific AuNPs, their unique characteristics and, importantly, tunability to achieve the desired optical/photothermal properties.

Targeted gold nanoshelled hybrid nanocapsules encapsulating doxorubicin for bimodal imaging and near-infrared triggered synergistic therapy of Her2-positve breast cancer

A multifunctional targeted nanoplatform combining photothermal therapy and chemotherapy has emerged as a promising strategy for comprehensive therapies of breast cancer. In this study, we constructed human epidermal growth factor receptor 2 (Her2)-targeted gold nanoshelled poly(lactic- co-glycolic acid) hybrid nanocapsules encapsulating perfluorooctyl bromide, superparamagnetic iron oxide nanoparticles, and doxorubicin (Her2-GPDH nanocapsules) as theranostic agent for bimodal ultrasound/magnetic resonance imaging and synergistic photothermal-chemotherapy of Her2-postive breast cancer cells. Her2–GPDH nanocomposites possessed well-defined spherical morphology, and the average diameter was about 296 nm with good dispersion. Targeting assays demonstrated that Her2–GPDH nanocapsules exhibited higher targeting binding to Her2-positive SKBR3 cells than Her2-negative MDA-MB-231cells. The encapsulation efficiency and the loading content of doxorubicin in Her2–GPDH nanocapsules were 39 ± 1.45% and 3.8 ± 0.52%, respectively, and the agent exhibited pH-responsive and near-infrared light-triggered stepwise release behavior of doxorubicin. In vitro, the agent had potential to serve as feasible candidate for ultrasound imaging and T2-weighted magnetic resonance imaging with a relatively high relaxivity. Cell experiments confirmed that the agent had significant photothermal cytotoxicity on SKBR3 cells, and the combined photothermal–chemotherapy could significantly enhance the anti-tumor effect. In summary, the present Her2–GPDH nanocapsules, a novel multifunctional nanoplatform, will offer a new way for early bimodal molecular-level diagnosis and synergistic treatment of Her2-positve breast cancer.

Theranostic application of nanoemulsions in chemotherapy

Theranostics has the potential to revolutionize the diagnosis, treatment, and prognosis of cancer, where novel drug delivery systems could be used to detect the disease at an early stage with instantaneous treatment. Various preclinical approaches of nanoemulsions with entrapped contrast and chemotherapeutic agents have been documented to act specifically on the tumor microenvironment (TME) for both diagnostic and therapeutic purposes. However, bringing these theranostic nanoemulsions through preclinical trials to patients requires several fundamental hurdles to be overcome, including the in vivo behavior of the delivery tool, degradation, and clearance from the system, as well as long-term toxicities. Here, we discuss recent advances in the application of nanoemulsions in molecular imaging with simultaneous therapeutic efficacy in a single delivery system.

The Pimpled Gold Nanosphere: A Superior Candidate for Plasmonic Photothermal Therapy

BACKGROUND

The development of highly efficient nanoparticles to convert light to heat for anti-cancer applications is quite a challenging field of research.

METHODS

In this study, we synthesized unique pimpled gold nanospheres (PGNSs) for plasmonic photothermal therapy (PPTT). The light-to-heat conversion capability of PGNSs and PPTT damage at the cellular level were investigated using a tissue phantom model. The ability of PGNSs to induce robust cellular damage was studied during cytotoxicity tests on colorectal adenocarcinoma (DLD-1) and fibroblast cell lines. Further, a numerical model of plasmonic (COMSOL Multiphysics) properties was used with the PPTT experimental assays.

RESULTS

A low cytotoxic effect of thiolated polyethylene glycol (SH-PEG400-SH-) was observed which improved the biocompatibility of PGNSs to maintain 89.4% cell viability during cytometry assays (in terms of fibroblast cells for 24 hrs at a concentration of 300 µg/mL). The heat generated from the nanoparticle-mediated phantom models resulted in ΔT=30°C, ΔT=23.1°C and ΔT=21°C for the PGNSs, AuNRs, and AuNPs, respectively (at a 300 µg/mL concentration and for 325 sec). For the in vitro assays of PPTT on cancer cells, the PGNS group induced a 68.78% lethality (apoptosis) on DLD-1 cells. Fluorescence microscopy results showed the destruction of cell membranes and nuclei for the PPTT group. Experiments further revealed a penetration depth of sufficient PPTT damage in a physical tumor model after hematoxylin and eosin (H&E) staining through pathological studies (at depths of 2, 3 and 4 cm). Severe structural damages were observed in the tissue model through an 808-nm laser exposed to the PGNSs.

CONCLUSION

Collectively, such results show much promise for the use of the present PGNSs and photothermal therapy for numerous anti-cancer applications.

The versatile biomedical applications of bismuth-based nanoparticles and composites: therapeutic, diagnostic, biosensing, and regenerative properties

Studies of nanosized forms of bismuth (Bi)-containing materials have recently expanded from optical, chemical, electronic, and engineering fields towards biomedicine, as a result of their safety, cost-effective fabrication processes, large surface area, high stability, and high versatility in terms of shape, size, and porosity. Bi, as a nontoxic and inexpensive diamagnetic heavy metal, has been used for the fabrication of various nanoparticles (NPs) with unique structural, physicochemical, and compositional features to combine various properties, such as a favourably high X-ray attenuation coefficient and near-infrared (NIR) absorbance, excellent light-to-heat conversion efficiency, and a long circulation half-life. These features have rendered bismuth-containing nanoparticles (BiNPs) with desirable performance for combined cancer therapy, photothermal and radiation therapy (RT), multimodal imaging, theranostics, drug delivery, biosensing, and tissue engineering. Bismuth oxyhalides (BiO_x, where X is Cl, Br or I) and bismuth chalcogenides, including bismuth oxide, bismuth sulfide, bismuth selenide, and bismuth telluride, have been heavily investigated for therapeutic purposes. The pharmacokinetics of these BiNPs can be easily improved via the facile modification of their surfaces with biocompatible polymers and proteins, resulting in enhanced colloidal stability, extended blood circulation, and reduced toxicity. Desirable antibacterial effects, bone regeneration potential, and tumor growth suppression under NIR laser radiation are the main biomedical research areas involving BiNPs that have opened up a new paradigm for their future clinical translation. This review emphasizes the synthesis and state-of-the-art progress related to the biomedical applications of BiNPs with different structures, sizes, and compositions. Furthermore, a comprehensive discussion focusing on challenges and future opportunities is presented.

Combinatorial discovery of Mo-based polyoxometalate clusters for tumor photothermal therapy and normal cell protection

Molybdenum (Mo)-based polyoxometalate clusters can kill cancer cells selectively by PTT assay and protect the normal cells by scavenging ROS effectively.

Plasmonic gold nanoparticles: Optical manipulation, imaging, drug delivery and therapy

Over the past two decades, the development of plasmonic nanoparticle (NPs), especially gold (Au) NPs, is being pursued more seriously in the medical fields such as imaging, drug delivery, and theranostic systems. However, there is no comprehensive review on the effect of the physical and chemical parameters of AuNPs on their plasmonic properties as well as the use of these unique characteristic in medical activities such as imaging and therapeutics. Therefore, in this literature the surface plasmon resonance (SPR) modeling of AuNPs was accurately captured toward precision medicine. Indeed, we investigated the importance of plasmonic properties of AuNPs in optical manipulation, imaging, drug delivery, and photothermal therapy (PTT) of cancerous cells based on their physicochemical properties. Finally, some challenges regarding the commercialization of AuNPs in future medicine such as, cytotoxicity, lack of standards for medical applications, high cost, and time-consuming process were discussed.

Her2-Functionalized Gold-Nanoshelled Magnetic Hybrid Nanoparticles: a Theranostic Agent for Dual-Modal Imaging and Photothermal Therapy of Breast Cancer

Targeted theranostic platform that integrates multi-modal imaging and therapeutic function is emerging as a promising strategy for earlier detection and precise treatment of cancer. Herein, we designed targeted gold-nanoshelled poly (lactic-co-glycolic acid) (PLGA) magnetic hybrid nanoparticles carrying anti-human epidermal growth factor receptor 2 (Her2) antibodies (Her2-GPH NPs) for dual-modal ultrasound (US)/magnetic resonance (MR) imaging and photothermal therapy of breast cancer. The agent was fabricated by coating gold nanoshell around PLGA nanoparticles co-loaded with perfluorooctyl bromide (PFOB) and superparamagnetic iron oxide nanoparticles (SPIOs), followed by conjugating with anti-Her2 antibodies. Cell-targeting studies demonstrated receptor-mediated specific binding of the agent to Her2-positive human breast cancer SKBR3 cells, and its binding rate was significantly higher than that of Her2-negative cells (P < 0.001). In vitro, the agent had capabilities for contrast-enhanced US imaging as well as T2-weighted MR imaging with a relatively high relaxivity (r2 = 441.47 mM-1 s-1). Furthermore, the Her2 functionalization of the agent prominently enhanced the US/MR molecular imaging effect of targeted cells by cell-specific binding. Live/dead cell assay and targeted photothermal cytotoxicity experiments confirmed that Her2-GPH NPs could serve as effective photoabsorbers to specifically induce SKBR3 cell death upon near-infrared laser irradiation. In summary, Her2-GPH NPs were demonstrated to be novel targeted theranostic agents with great potential to facilitate early non-invasive diagnosis and adjuvant therapy of breast cancer.

Glutathione depletion and dual-model oxygen balance disruption for photodynamic therapy enhancement

Photodynamic therapy (PDT) is a prospective approach to cure tumor diseases. However, tumor micro-environment is notably characterized with severe hypoxia and high expression of glutathione (GSH), which seriously limit its clinical application. Here, based on the characteristics of perfluorocarbon (PFC) to dissolve substantial oxygen (O₂) and the sensitivity of reductive GSH to S-NO group, we designed GSH depletion and dual-model O₂ supply strategies to promote PDT enhancement. The PFC nanoliposomes (FI@Lip) and biocompatible NO donor S-nitrosated human serum albumin (HSA-SNO) were combined to synergistically combat the obstacle of tumor micro-environment, reducing GSH concentration and increasing singlet oxygen (¹O₂) generation. In vitro, after irradiation with NIR laser, the PFC in FI@Lip dissolved more O₂ to increase ¹O₂ generation. In addition, with co-delivery of HSA-SNO, it can effectively promote GSH depletion to recover ¹O₂ level and release NO concurrently to inhibit mitochondrial respiration. This combination strategy of FI@Lip and HSA-SNO obviously relieved intracellular hypoxia and decreased GSH to increase more toxic ¹O₂ generation for PDT enhancement. The present work will play as an enlightening role in PDT design and clinical application in the near future.

Photothermal and gene therapy combined with immunotherapy to gastric cancer by the gold nanoshell-based system

BACKGROUND

The gastric cancer is the second most malignant tumor in the world. HER-2 is one of the key targets for the gastric cancer therapy. Anti-HER-2 antibodies like trastuzumab, exhibits the satisfactory therapeutic effect in clinical. However, the drug resistance problem limits its application.

METHOD

In this study, we develop a gold nanoshell (Gold Nanoshell) drug carrier for delivery and selective photo-thermal release of genes which target HER-2 and immunologic adjuvant CPG sequence in gastric tumor cells. The drug delivery system generated a multidimensional treatment strategy which includes gene-, immune- and photothermal-therapy.

RESULTS

The whole gold nanoshell drug delivery system exhibits the well gene transduction ability and combined treatment effect. Both in vitro and in vivo results demonstrate the multiple therapeutic effects of the drug delivery system is better than the monotherapy.

CONCLUSIONS

This study indicates the multiple combined therapy based on the gold nanoshell system would be a promising translational treatment for gastric cancer.

Gold Cube-in-Cube Based Oxygen Nanogenerator: A Theranostic Nanoplatform for Modulating Tumor Microenvironment for Precise Chemo-Phototherapy and Multimodal Imaging

Engineering a versatile oncotherapy nanoplatform integrating both diagnostic and therapeutic functions has always been an intractable challenge in targeted cancer treatment. Herein, to actualize the theme of precise medicine, a nanoplatform is developed by anchoring Mn-Cdots to doxorubicin (DOX)-loaded mesoporous silica-coated gold cube-in-cubes core/shell nanocomposites and further conjugating them to a Arg-Gly-Asp (RGD) peptide (denoted as RGD-CCmMC/DOX) to achieve an active-targeting effect. Under 635 nm irradiation, the nanoplatform acts as oxygen nanogenerator that produces O₂ in situ and amplifies the content of singlet oxygen (¹O₂) in the hypoxic tumor microenvironment (TME), which has been demonstrated to attenuate tumor hypoxia and synchronously enhance photodynamic efficacy. Moreover, the gold cube-in-cube core in this work has been proven as a photothermal agent for hyperthermia, which exhibits a favorable photothermal effect with a 65.6% calculated photothermal conversion efficiency under 808 nm irradiation. In addition, the nanoplatform achieves heat- and pH-sensitive drug release with precise control to specific-tumor sites, executing combined chemo-phototherapy functions. Besides, it functions as a multimodal bioimaging agent of photothermal, fluorescence, and magnetic resonance imaging for the accurate diagnosis and guidance of therapy. As validated by in vivo and in vitro assays, the TME-responsive nanoplatform is highly biocompatible and effectively obliterates 4T1 tumor xenografts on nude mice after triple-synergetic treatment. This work presents a rational design of versatile nanoplatforms, which modulate the TME to enable high therapeutic performance and multiplexed imaging, which provides an innovative paradigm for targeted tumor therapy.

T98G Cell Death Induced by Photothermal Treatment with Hollow Gold Nanoshell-Coupled Silica Microrods Prepared from Escherichia Coli

As an alternative to traditional cancer treatment, photothermal therapy is a promising method with advantages such as noninvasiveness and high efficiency. Herein, we synthesized armored golden Escherichia coli (AGE) microrods as photothermal agents to evaluate the viability of cancer cell. The hollow gold nanoshell (HAuNS) was synthesized for photothermal effects under the near-infrared (NIR) region using unicellular E. coli as a framework. Coupling HAuNS onto the surface of E. coli@SiO₂ enhanced temperature elevation and resulted in high conversion efficiency. The synthesized AGE microrods had excellent photothermal stability under NIR laser irradiation in the five-times recycling experiment. The temperature elevation of AGE microrod solution reached 43.7 °C, which induced hyperthermia-mediated killing of tumor cells. The results of the cytotoxicity test revealed the AGE microrod-induced T98G cell death mediated via apoptosis.

A selenium-containing selective histone deacetylase 6 inhibitor for targeted in vivo breast tumor imaging and therapy

We have developed a HDAC6-selective inhibitor, SelSA, which can be utilized as a target for the detection and treatment of ERα(+) breast cancer and TNBC. The biodistribution study showed that SelSA can specifically target the breast tumor and display potent antitumor effects in vivo. This result will help to better improve the treatment efficacy against breast cancer.

Dual-Stimuli Responsive Bismuth Nanoraspberries for Multimodal Imaging and Combined Cancer Therapy

Development of stimuli-responsive theranostics is of great importance for precise cancer diagnosis and treatment. Herein, bovine serum albumin (BSA) modified bismuth nanoraspberries (Bi-BSA NRs) are developed as cancer theranostic agents for multimodal imaging and chemo-photothermal combination therapy. The Bi-BSA NRs are synthesized in aqueous phase via a facile reduction method using Bi₂O₃ nanospheres as the sacrificial template. The morphology, biocompatibility, photothermal effect, drug loading/releasing abilities, chemotherapy effect, synergistic chemo-photothermal therapy efficacy, and multimodal imaging capacities of Bi-BSA NRs have been investigated. The results show that the NRs possess multiple unique features including (i) raspberry-like morphology with high specific surface area (∼52.24 m²·g^-1) and large cavity (total pore volume ∼0.30 cm³·g^-1), promising high drug loading capacity (∼69 wt %); (ii) dual-stimuli responsive drug release, triggered by acidic pH and NIR laser irradiation; (iii) infrared thermal (IRT), photoacoustic (PA) and X-ray computed tomography (CT) trimodality imaging with the CT contrast enhanced efficiency as high as ∼66.7 HU·mL·mg^-1; (iv) 100% tumor elimination through the combination chemo-photothermal therapy. Our work highlights the great potentials of Bi-BSA NRs as a versatile theranostics for multimodal imaging and combination therapy.

Iron oxide/bismuth oxide nanocomposites coated by graphene quantum dots: "Three-in-one" theranostic agents for simultaneous CT/MR imaging-guided in vitro photothermal therapy

BACKGROUND

The all-in-one nanoprobes (NPs) have drawn biomedical attention in the cancer therapy field due to simultaneously combing the capabilities of therapeutic and diagnostic methods into a single nanoprobe.

METHOD

In this study, we developed a theranostic probe based on superparamagnetic iron oxide (SPIO) and bismuth oxide (Bi₂O₃) with graphene quantum dots (GQDs) coating to investigate the physical properties for in vitro CT/MR dual-modal biomedical imaging and cancer-specific photothermal therapy (PTT).

RESULT

The GQDs-Fe/Bi nanocomposites showed strong light absorbance profile with wide-band in the near-infrared region, without any sharp peak or decline. The highest photo-to-thermal conversion efficacy (η), was found to be 31.8% with the high photostability upon the irradiation of NIR 808-nm laser. The results of in vitro photothermal ablation of cancerous cells demonstrated that the cells significantly killed in the presence of NPs (∼53.4%) with a dose-dependent manner in comparison to only laser group (3.0%). In GQDs-Fe/Bi nanocomposites, Bi with a high atomic number (Z = 83) exhibited a superior X-ray attenuation capability (175%) than the clinical CT agent-used dotarem, also, SPIO with excellent magnetization property showed strong T₂-relaxation shortening capability (r₂ = 62.34 mM^-1.s^-1) as a contrast agent for CT/MR imaging.

CONCLUSION

Our results demonstrate that the developed NPs can incorporate dual-modality imaging capability into a photo absorber for CT/MR imaging-guided tumor PTT.

Graphene Quantum Dots-Coated Bismuth Nanoparticles for Improved CT Imaging and Photothermal Performance

By integrating high-performance CT imaging and photothermal therapy (PTT) into one nanoprobe, an effective theranostic can be achieved for clinical cancer treatment. In this study, the graphene quantum dots (GQDs)-coated bismuth (Bi) nanoparticle (NP) as a theranostic nanoprobe is synthesized and its capabilities for computed tomography (CT) imaging and PTT are investigated. Such nanotheranostic exhibits good physiological dispersity with satisfactory blood compatibility and cytotoxicity. Most importantly, the GQDs-Bi NPs offer strong and steady absorbance profile in NIR region with excellent photostability, which can remarkably convert photo-to-thermal with the photothermal efficiency of 30.0%. Thanks to the powerful PTT effect, co-delivery of GQDs-Bi NPs/NIR laser can effectively induce HeLa cells death in vitro. Cooperatively, NPs hold X-ray attenuation coefficient for high-contrast CT imaging with the corresponding CT improvement efficacy as high as 32.7[Formula: see text]HU[Formula: see text]mg[Formula: see text]. The obtained results highlight the potential of GQDs-Bi NPs as a successful theranostic nanoagent for CT imaging and cancer photothermal therapy.

Mesoporous silica-coated bismuth nanohybrids as a new platform for photoacoustic/computed tomography imaging and synergistic chemophotothermal therapy

AIM

Polyethylene glycol modified mesoporous silica-coated bismuth nanohybrids (Bi@mSiO₂-PEG) are fabricated for chemothermotherapy and multimodal imaging.

MATERIALS & METHODS

The Bi@mSiO₂-PEG are synthesized by coating mesoporous SiO₂ onto metallic Bi cores, followed by PEG modification. Their cytotoxicity, photothermal effect, drug loading, antitumor effect and imaging abilities are evaluated.

RESULTS

The nanohybrids show good biocompatibility, strong near-infrared absorbance, high photothermal conversion efficiency (∼36.6%), prominent infrared thermal imaging and photothermal killing efficacy on cancer cells. Utilizing the nanohybrids as potent drug carriers, a synergistic antitumor effect through chemothermotherapy is realized. Thanks to the superhigh x-ray attenuation coefficient and strong photothermal ability, high-contrast photoacoustic and x-ray computed tomography imaging are achieved.

CONCLUSION

These results reveal great potentials of the Bi@mSiO₂-PEG for precise and efficient anticancer treatments.

Gold nanoparticles-mediated photothermal therapy and immunotherapy

Cancer has been a significant threat to human health with more than eight million deaths each year in the world. Therefore, there is a significant need for novel technologies to effectively treat cancer and ultimately reduce cancer recurrences, treatment costs, number of radical cystectomies and mortality. A promising therapeutic platform for cancer is offered by nanoparticle-mediated therapy. This review highlights the development and applications of various nanoparticle platforms for photo-induced hyperthermia and immunotherapy. Taking advantage of gold's high biocompatibility, gold nanoparticles (GNPs) can be injected intravenously and accumulate preferentially in cancer cells due to the enhanced permeability and retention effect. Various gold nanoplatforms including nanospheres, nanoshells, nanorods, nanocages and nanostars have been used for effective photothermal treatment of various cancers. GNPs have also been used in immunotherapies, involving cancer antigen and immune adjuvant delivery as well as combination therapies with photothermal therapy. Among GNPs platforms, gold nanostars (GNS) have great therapeutic potential due to their unique star-shaped geometry that dramatically enhances light absorption and provides high photon-to-heat conversion efficiency due to the plasmonic effect. This photothermal process can be exploited to specifically ablate tumors and, more importantly, to amplify the antitumor immune response following the highly immunogenic thermal death of cancer cells. GNS-mediated photothermal therapy combined with checkpoint immunotherapy has been found to reverse tumor-mediated immunosuppression, thereby leading to the treatment of not only primary tumors but also cancer metastasis, as well as to induce effective long-lasting immunity, in other words, an anticancer ‘vaccine’ effect.

Noninvasive photothermal cancer therapy nanoplatforms via integrating nanomaterials and functional polymers

In the cutting-edge field of cancer therapy, noninvasive photothermal therapy (PTT) has received great attention because it is considered to overcome the drawbacks of conventional surgery, radiotherapy and chemotherapy of severe body injuries and side effects on the immune system. The construction of PTT therapeutic and theranostic nanoplatforms is the key issue in achieving tumor targeting, imaging and therapy in a synergetic manner. In this review, we focus on the recent advances in constructing PTT therapeutic and theranostic nanoplatforms by integrating nanomaterials and functional polymers. The noninvasive photothermal cancer therapy mechanism and achievement strategies of PTT therapeutic and theranostic nanoplatforms are presented as well as the innovative construction strategies and perspectives for the future. Owing to their high tumor ablation efficiency, biological availability and low- or non-toxicity, PTT therapeutic and theranostic nanoplatforms are promising and emerging in medicine and clinical applications.

Perfluorooctylbromide nanoparticles for ultrasound imaging and drug delivery

Perfluorooctylbromide nanoparticles (PFOB NPs) are a type of multifunctional nanotechnology that has been studied for various medical applications. Commercial ultrasound contrast agents (UCAs) suffer from the following limitations: short half-lives in vivo, high background signal and restricted distribution in the vascular circulation due to their micrometer dimensions. PFOB NPs are new potential UCAs that persist for long periods in the circulatory system, possess a relatively stable echogenic response without increasing the background signal and exhibit lower acoustic attenuation than commercial UCAs. Furthermore, PFOB NPs may also serve as drug delivery vehicles in which drugs are dissolved in the outer lipid or polymer layer for subsequent delivery to target sites in site-targeted therapy. The use of PFOB NPs as carriers has the potential advantage of selectively delivering payloads to the target site while improving visualization of the site using ultrasound (US) imaging. Unfortunately, the application of PFOB NPs to the field of ultrasonography has been limited because of the low intensity of US reflection. Numerous researchers have realized the potential use of PFOB NPs as UCAs and thus have developed alternative approaches to apply PFOB NPs in ultrasonography. In this article, we review the latest approaches for using PFOB NPs to enhance US imaging in vivo. In addition, this article emphasizes the application of PFOB NPs as promising drug delivery carriers for cancer and atherosclerosis treatments, as PFOB NPs can transport different drug payloads for various applications with good efficacy. We also note the challenges and future study directions for the application of PFOB NPs as both a delivery system for therapeutic agents and a diagnostic agent for ultrasonography.

Ultrasound Contrast Agents and Delivery Systems in Cancer Detection and Therapy

Ultrasound is the second most utilized imaging modality in the world because it is widely accessible, robust, and safe. Aside from its extensive use in diagnostic imaging, ultrasound has also been frequently utilized in therapeutic applications. Particularly, when combined with appropriate delivery systems, ultrasound provides a flexible platform for simultaneous real-time imaging and triggered release, enabling precise, on-demand drug delivery to target sites. This chapter will discuss the basics of ultrasound including its mechanism of action and how it can be used to trigger the release of encapsulated drug either through thermal or cavitation effects. Fundamentals of ultrasound contrast agents, how they enhance ultrasound signals, and how they can be modified to function as carriers for triggered and targeted release of drugs will also be discussed.

A novel non-invasive strategy for low-level laser-induced cancer therapy by using new Ag/ZnO and Nd/ZnO functionalized reduced graphene oxide nanocomposites

In the present research, an effective drug-free approach was developed to kill MCF7 breast cancer cells using low-level laser therapy (LLLT) combined with reduced graphene oxide (rGO)-based hybrid nanocomposites (NCs). Here, fruit extract of Rosa canina was used for the first time to obtain the rGO/ZnO, Ag-ZnO/rGO and Nd-ZnO/rGO NCs by green synthesis. Physico/photochemical properties of these NCs were evaluated using FTIR, XRD, Raman, XPS, SEM/EDX, UV-Vis, DLS and AFM. The potential of the as-synthesized NCs on ROS generating and antioxidant activity were assessed by DPPH. After optimizing the proper concentration of the NCs their anti-tumoral efficacy were evaluated by DAPI staining and MTT assay tests for laser therapy on MCF7 breast cancer cells. Interestingly, cell death was increased dramatically by increasing irradiation dose from 8-32 J/cm² and then decreased by enhancing laser dose. The maximum amount of cell death is 50% which was observed in the presence of ZnO/rGO 20% by irradiation dose of 32 J/cm². Furthermore, in comparison with 810 nm, 630 nm lasers were more effective in LLLT of MCF7 cells. The results show the potential of using rGO-based NCs in LLLT, which may be combined with other therapeutic approaches to assist our fight against cancer.

Ultrasound molecular imaging of breast cancer in MCF-7 orthotopic mice using gold nanoshelled poly(lactic-co-glycolic acid) nanocapsules: a novel dual-targeted ultrasound contrast agent

BACKGROUND

The development of nanoscale molecularly targeted ultrasound contrast agents (UCAs) with high affinity and specificity is critical for ultrasound molecular imaging in the early detection of breast cancer.

PURPOSE

To prospectively evaluate ultrasound molecular imaging with dual-targeted gold nanoshelled poly(lactide-co-glycolic acid) nanocapsules carrying vascular endothelial growth factor receptor type 2 (VEGFR2) and p53 antibodies (DNCs) in MCF-7 orthotopic mice model.

METHODS

DNCs were fabricated with an inner PLGA and outer gold nanoshell spherical structure. Its targeting capabilities were evaluated by confocal laser scanning microscopy (CLSM) and flow cytometry (FCM) in vitro. Contrast-enhanced ultrasound imaging (CEUS) with DNCs was evaluated qualitatively and quantitatively in vitro and in MCF-7 orthotopic mice model by two different systems. The biodistribution of NCs in mice was preliminary investigated. Differences were calculated by using analysis of variance.

RESULTS

DNCs showed a well-defined spherical morphology with an average diameter of 276.90±110.50 nm. In vitro, DNCs exhibited high target specificities (79.01±5.63% vs. 2.11±1.07%, P<0.01; 75.54±6.58% vs. 5.21±3.12%, P<0.01) in VEGFR2- and p53-positive cells compared with control cells. In vivo, CEUS displayed a significantly higher video intensity in two systems using DNCs in comparison with non-targeted PLGA@Au NCs and single-targeted NCs. Biodistribution studies revealed that more DNCs in breast cancer tissue could be detected in mice than in other NCs (P<0.05).

CONCLUSION

DNCs were demonstrated to be novel dual-targeted UCAs and may have potential applications in early non-invasive visualization of breast cancer.

Iodinated Echogenic Glycol Chitosan Nanoparticles for X-ray CT/US Dual Imaging of Tumor

Development of biopolymer-based imaging agents which can access rapidly and provide detailed information about the diseases has received much attention as an alternative to conventional imaging agents. However, development of biopolymer-based nanomaterials for tumor imaging still remains challenging due to their low sensitivity and image resolution. To surmount of these limitations, multimodal imaging agents have been developed, and they were widely utilized for theranostic applications. Herein, iodine containing echogenic glycol chitosan nanoparticles are developed for x-ray computed tomography (CT) and ultrasound (US) imaging of tumor diagnosis. X-ray CT/US dual-modal imaging probe was prepared by following below two steps. First, iodine-contained diatrizoic acid (DTA) was chemically conjugated to the glycol chitosan (GC) for the CT imaging. DTA conjugated GC (GC-DTA NPs) formed stable nanoparticles with an average diameter of 315 nm. Second, perfluoropentane (PFP), a US imaging agent, was physically encapsulated into GC-DTA NPs by O/W emulsion method yielding GC-DTA-PFP nanoparticles (GC-DTA-PFP NPs). The GC-DTA-PFP NPs formed nanoparticles in physiological condition, and they presented the strong x-ray CT, and US signals in phantom test in vitro. Importantly, GC-DTA-PFP NPs were effectively accumulated on the tumor site by enhanced permeation and retention (EPR) effects. Moreover, GC-DTA-PFP NPs showed x-ray CT, and US signals in tumor tissues after intratumoral and intravenous injection, respectively. Therefore, GC-DTA-PFP NPs indicated that x-ray CT/US dual-modal imaging using iodinated echogenic nanoparticles could be provided more comprehensive and accurate diagnostic information to diagnosis of tumor.

Near-infrared photothermal therapy using anti-EGFR-gold nanorod conjugates for triple negative breast cancer

Current EGFR-targeted therapy for triple negative breast cancer (TNBC) has produced disappointing results. A rational therapeutic strategy to improve EGFR-targeted treatment for TNBC is therefore needed. In this study we evaluated the feasibility of treating TNBC using photoacoustic imaging (PAI)-guided near-infrared photothermal therapy (NIR-PTT) with anti-EGFR-conjugated gold nanorods (anti-EGFR-GN). NIR-PTT combined with anti-EGFR-GN exerted synergistic anti-proliferative and apoptotic actions through upregulation of HSP70 and cleaved caspase-3, downregulation of Ki-67 and EGFR, and inhibition of several intracellular signaling molecules (mTOR, AKT, ERK1/2 and FAK). These combined effects give this approach significant efficacy. Our findings suggest PAI-guided NIR-PTT using anti-EGFR-GN represent a novel and effective strategy for EGFR-targeted therapy in TNBC.