Contrast Agent For Computed Tomography Imaging Research Articles

Toward the Clinical Translation of Safe Intravenous Long Circulating Iodinated Lipid Nanoemulsion Contrast Agents for CT Imaging.

Current clinical small molecule x-ray CT agents are effective but pose risks such as nephrotoxicity, short blood circulation time, limiting scan durations, potential thyroid impact, and immune responses. These challenges drive the development of kidney-safe x-ray nanoparticle (NP)-based contrast agents (CAs), though translation to clinical practice is hindered by chemical complexities and potential toxicity. We have engineered an intravenous, injectable, and safe blood pool NP-based CT CAs at a clinical-equivalent dose of ∼300 mgI/kg (∼2 mL/kg), ideal for vascular and hepatic imaging which are limited by clinical agents. Our iodinated lipid nanodroplet emulsions (ILNEs) contrast agent offers high x-ray attenuation thus improved contrast enhancement, extended stability, and exceptional batch-to-batch consistency. It also boasts a straightforward and scalable manufacturing process with minimal protein interaction, prolonged blood residency (∼4h), and hepatic clearance within 3 days, avoiding nephrotoxicity. Studies in vitro, in mice, and 16.6kg porcine animal model studies confirm its safety, cytocompatibility, and absence of tissue damage. Blood, and thyroid-stimulating hormone (TSH) analyses, and kidney and liver function tests, also support further toxicity evaluations for clinical translation.

Multi-enzyme mimetic iridium nanozymes-based thrombus microenvironment-modulated nanoplatform for enhanced thrombolytic therapy

Intravenous injection of thrombolytic drugs is the most feasible strategy for the clinical treatment of thrombotic diseases, however, its applications are yet limited by narrow therapeutic index, short half-life, and hemorrhagic risk. Inspired by the excessive ROS and inflammatory factors at the thrombus site, we manufactured a thrombus microenvironment-modulated nanosystem, which achieved the targeted delivery of thrombolytic drugs and ROS scavenging agents. Ir monomers (Ir-PVP) with enzyme-mimetic activity were prepared and then wrapped with lumbrokinase (LK) by HA materials of thrombo-inflammatory affinity, forming multifunctional thrombolytic agents Ir-LK@HA. Ir-LK@HA could prolong the biological half-life of LK and target the thrombus site to release LK with reduced bleeding risk. Moreover, Ir-NPs, as both CT imaging contrast agent and ROS scavenger, not only allowed us to observe the progression of thrombolytic treatment through CT imaging in real time, but also played an important role in elimination of excessive ROS at thrombus site. Taken together, the in vitro and in vivo experiments illustrated that Ir-LK@HA with CT function displayed an excellent efficiency in thrombolysis, anti-inflammation and ROS scavenging. Our work may encourage further exploration of thrombus microenvironment-modulated theranostic platforms.

Multifunctional Bi NSs@BSA Nanoplatform Guided by CT Imaging for Effective Photothermal Therapy.

Photothermal therapy (PTT) has attracted great attention as an anticancer treatment strategy. With the rapid development of nanomedicine, multifunctional inorganic nanophotothermal agents provide a new way to improve the effect of PTT. Herein, bovine serum albumin (BSA)-modified Bi nanosheets (Bi NSs) with good biocompatibility were synthesized by a facile redox and ball milling method and applied as a photothermal agent for the enhancement of PTT. Owing to the strong near-infrared absorption, Bi NSs exhibit high photothermal conversion efficiency (η = 36.17%) under 808 nm laser irradiation and can serve as a nanotherapeutic agent for cancer therapy. In addition, in vitro cell safety analysis also suggests that the toxicity of BSA-modified Bi NSs is negligible. Upon 808 nm irradiation, the uptake ability of tumor cells to Bi NSs@BSA has been improved. Moreover, Bi NSs@BSA also can be used as a good contrast agent for CT imaging and then to observe the distribution of materials in the tumor site. Finally, Bi NSs@BSA-mediated PTT results show a high ablation rate of A549 tumor cells both in vitro and in vivo. All results reveal that Bi NSs@BSA is a promising nanotherapeutic platform for PTT.

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.

PVP-Modified Multifunctional Bi2WO6 Nanosheets for Enhanced CT Imaging and Cancer Radiotherapy.

Malignant tumors are one of the main causes of human death. The clinical treatment of malignant tumors is usually surgery, chemotherapy, radiotherapy, and so forth. Radiotherapy, as a traditional and effective treatment method for cancer, is widely used in clinical practice, but the radiation resistance of tumor cells and the toxic side effects to normal cells are still the Achilles heel of radiotherapy. Multifunctional inorganic high-atom nanomaterials are expected to enhance the effect of tumor radiotherapy. Tungsten and bismuth, which contain elements with high atomic coefficients, have strong X-ray energy attenuation capability. We synthesized Bi2WO6 nanosheets (NSs) using a hydrothermal synthesis method and modified polyvinylpyrrolidone (PVP) on their surface to make them more stable. PVP–Bi2WO6 NSs have a variety of effects after absorbing X-rays (such as the photoelectric effect and Compton effect) and release a variety of particles such as photoelectrons, Compton electrons, auger electrons, and so forth, which can react with organic molecules or water in cells, generate a large number of free radicals, and promote cell apoptosis, thereby improving the effect of radiotherapy. We show through γ-H2AX and DCFH-DA probe analysis experiments that PVP–Bi2WO6 NSs can effectively increase cell DNA damage and reactive oxygen species formation under X-ray irradiation. Clone formation analysis showed that PVP–Bi2WO6 NSs can effectively suppress cell colony formation under X-ray irradiation. These versatile functions endow PVP–Bi2WO6 NSs with enhanced radiotherapy efficacy in animal models. In addition, PVP–Bi2WO6 NSs can also be used as contrast agents for X-ray computed tomography (CT) imaging with obvious effects. Therefore, PVP–Bi2WO6 NSs can be used as CT imaging contrast agents and tumor radiotherapy sensitizers and have potential medical applications.

Near-Infrared Upconversion Mesoporous Tin Dioxide Theranostic Nanocapsules for Synergetic Cancer Chemophototherapy.

Smart nanotheranostic systems (SNSs) have attracted extensive attention in antitumor therapy. Nevertheless, constructing SNSs with disease diagnosis ability, improved drug delivery efficiency, inherent imaging performance, and high treatment efficiency remains a scientific challenge. Herein, ultrasmall tin dioxide (SnO2) was assembled with upconversion nanoparticles (UCNPs) to form mesoporous nanocapsules by an in situ hydrothermal deposition method, followed by loading with doxorubicin (DOX) and modification with bovine serum albumin (BSA). pH/near-infrared dual-responsive nanotheranostics was constructed for computed tomography (CT) and magnetic resonance (MR) imaging-induced collaborative cancer treatment. The mesoporous channel of SnO2 was utilized as a reservoir to encapsulate DOX, an antineoplastic drug, for chemotherapy and as a semiconductor photosensitizer for photodynamic therapy (PDT). Furthermore, the DOX-loaded UCNPs@SnO2-BSA nanocapsules combined PDT, Nd3+-doped UCNP-triggered hyperthermia effect, and DOX-triggered chemotherapy simultaneously and demonstrated prominently enhanced treatment efficiency compared to the monotherapy model. Moreover, tin, as one of the trace elements in the human body, has a similar X-ray attenuation coefficient to iodine and therefore can act as a contrast agent for CT imaging to monitor the treatment process. Such an orchestrated synergistic anticancer treatment exhibited apparent inhibition of tumor growth in tumor-bearing mice with negligible side effects. Our study demonstrates nanocapsules with excellent biocompatibility and great potential for cancer treatment.

Complete ablation of tumors using synchronous chemoradiation with bimetallic theranostic nanoparticles

Synchronous chemotherapy and radiotherapy, termed chemoradiation therapy, is now an important standard regime for synergistic cancer treatment. For such treatment, nanoparticles can serve as improved carriers of chemotherapeutics into tumors and as better radiosensitizers for localized radiotherapy. Herein, we designed a Schottky-type theranostic heterostructure, Bi2S3–Au, with deep level defects (DLDs) in Bi2S3 as a nano-radiosensitizer and CT imaging contrast agent which can generate reactive free radicals to initiate DNA damage within tumor cells under X-ray irradiation. Methotrexate (MTX) was conjugated onto the Bi2S3–Au nanoparticles as a chemotherapeutic agent showing enzymatic stimuli-responsive release behavior. The designed hybrid system also contained curcumin (CUR), which cannot only serve as a nutritional supplement for chemotherapy, but also can play an important role in the radioprotection of normal cells. Impressively, this combined one-dose chemoradiation therapeutic injection of co-drug loaded bimetallic multifunctional theranostic nanoparticles with a one-time clinical X-ray irradiation, completely eradicated tumors in mice after approximately 20 days after irradiation showing extremely effective anticancer efficacy which should be further studied for numerous anti-cancer applications.

Folic Acid-Conjugated Gold Nanostars for Computed Tomography Imaging and Photothermal/Radiation Combined Therapy

Fabrication of multifunctional nanoprobes, which integrate tumor targeting, imaging, and effective treatment, has been widely explored in nanomedicine. In the present study, we fabricated tumor-targeting polymer folic acid-terminated polyethylene glycol thiol-modified gold nanostars (GNS-FA), which could realize X-ray computed tomography (CT) imaging and PTT/RT synergistic therapy. The synthesized GNS-FA exhibited good biocompatibility. GNS-FA could be used as a CT imaging contrast agent due to the strong X-ray attenuation of Au. GNS-FA exhibited good near-infrared (NIR) light absorption and excellent photothermal conversion performance, making them promising photothermal transduction agents (PTAs). Furthermore, GNS-FA could be used as an RT sensitizer to enhance the radio-mediated cell death due to the high atomic number (high Z) of gold. Hence, GNS-FA were used as the CT imaging agent, PTA, and radiosensitizer in this work. The in vitro antitumor experiments showed that the PTT/RT combined treatment had enhanced anticancer efficacy compared with the monotherapy (PTT or RT). Our results indicated that the bioconjugated GNS could offer an excellent nanoplatform for CT imaging-guided PTT/RT combined cancer therapy in the future.

Nanoparticles: Untying the Gordian Knot in Conventional Computed Tomography Imaging

X-ray computed tomography (CT) imaging plays an essential role in disease diagnosis due to its noninvasive, painless mode and superior penetration depth. However, the resolution of the soft tissue ...

Decorating rare-earth fluoride upconversion nanoparticles on AuNRs@Ag core–shell structure for NIR light-mediated photothermal therapy and bioimaging

Photothermal therapy (PTT) has presented its inherent application value in cancer treatment. Nevertheless, single-functional photothermal materials cannot meet the precise diagnosis and treatment of cancer. Therefore, it is important to design a nanocomposite that has both high therapeutic efficiency and multimodal imaging capabilities. In our work, a new nanostructure of gold nanorods (AuNRs) with silver shells decorated by BaGdF5:Yb3+,Er3+ nanoparticle was synthesized by a simple way. The biostability of AuNRs is increased by coating with silver shells, and the AuNR@Ag nanoparticles can be used as excellent surface enhanced Raman scattering (SERS) probe. Moreover, the modification of BaGdF5:Yb3+,Er3+ nanoparticles provides the possibility of real-time optical imaging of the tumor area. Under the irradiation of NIR laser, the AuNR@Ag/BaGdF5:Yb3+,Er3+ nanocomposites (NCs) have strong upconversion emission and excellent photothermal conversion efficiency. Meanwhile, the NCs show low cytotoxicity and good biocompatibility in MTT cytotoxicity test. Moreover, the NCs are also exceptional contrast agents for CT imaging. For invitro photothermal therapy test, NCs show excellent killing efficiency on tumor cells. Therefore, the multifaceted research of AuNR@Ag/BaGdF5:Yb3+,Er3+ multifunctional nanomaterials provides a break for high-efficiency tumor photothermal therapy and multimodal imaging.

Engineering two-dimensional silicene composite nanosheets for dual-sensitized and photonic hyperthermia-augmented cancer radiotherapy

The rapid development of nanotechnology has triggered the emerging of tremendous theranostic nanoplatforms for combating cancers. Silicene, as an emerging two-dimensional (2D) material, has been recently explored as therapeutic agent due to their desirable biodegradation and strong photothermal-conversion performance. However, the rational design of silicene-based composites for further exerting multifunctional medical applications is still highly challenging. Herein, we report on the construction of silicene-based silicene@Pt composite nanosheets for computed tomography (CT)/photoacoustic (PA) imaging-guided dual-sensitized radiotherapy combined with photonic tumor hyperthermia, which has been achieved by a seed-growth approach to in situ grow Pt components onto silicene nanosheets’ surface. Especially, by functionalization of Pt components, these nanosheets could act as both contrast agents for CT imaging and dual radio-sensitizing agents for radiotherapy, which could deposit Pt-involved radiation energy (sensitized therapeutic process I) and overcome hypoxia-associated radio-resistance by Pt-catalytic O2 generation from overexpressed H2O2 within the tumor microenvironment (sensitized therapeutic process II). The strong photothermal-conversion performance of silicene nanosheets not only endowed silicene@Pt composite nanosheets with photoacoustic imaging property, but also realized the photonic tumor hyperthermia and achieved a combined therapeutic effect with radiotherapy. This work not only broadens the biomedical applications of silicene, but also develops functionalization strategies of silicene for versatile biomedical applications.

Bismuth chelate as a contrast agent for X-ray computed tomography

BackgroundsDue to the unexpected side effects of the iodinated contrast agents, novel contrast agents for X-ray computed tomography (CT) imaging are urgently needed. Nanoparticles made by heavy metal elements are often employed, such as gold and bismuth. These nanoparticles have the advantages of long in vivo circulation time and tumor targeted ability. However, due to the long residence time in vivo, these nanoparticles may bring unexpected toxicity and, the preparation methods of these nanoparticles are complicated and time—consuming.MethodsIn this investigation, a small molecular bismuth chelate using diethylenetriaminepentaacetic acid (DPTA) as the chelating agent was proposed to be an ideal CT contrast agent.ResultsThe preparation method is easy and cost—effective. Moreover, the bismuth agent show better CT imaging for kidney than iohexol in the aspect of improved CT values. Up to 500 µM, the bismuth agent show negligible toxicity to L02 cells and negligible hemolysis. And, the bismuth agent did not induce detectable morphology changes to the main organs of the mice after intravenously repeated administration at a high dose of 250 mg/kg. The pharmacokinetics of the bismuth agent follows the first—order elimination kinetics and, it has a short half—life time of 0.602 h. The rapid clearance from the body promised its excellent biocompatibility.ConclusionsThis bismuth agent may serve as a potential candidate for developing novel contrast agent for CT imaging in clinical applications.

Barley leaves mediated biosynthesis of Au nanomaterials as a potential contrast agent for computed tomography imaging

Over the past few years, environment-friendly green synthetic methods for metal nanoparticles (NPs) have received considerable attention. The use of plant extracts is considered as potential for the biosynthesis of metal NPs due to its easier obtainment, cheap accessibility to industrial scale-up and high biosecurity. Herein, with the aqueous leaf extract of barley leaves as the template, we reported a rapid, single step, cost-effective and eco-friendly synthetic route to prepare new gold nanoparticles (BL-Au NPs). Significantly, except for the key role as the reducing, barley leaves was further utilized as the capping agent that ensure the stability of the BL-Au NPs. The characterization results of TEM, FTIR and UV-vis indicated that the gold nanoparticles coated with barley leaves extract were successfully synthesized. In vitro and zebra fish toxicity and stability assays demonstrated its good biocompatibility and high colloidal stability. The CT images in vitro demonstrated that the constructed BL-Au NPs possessed superiority in X-ray attenuation ability compared to clinically commonly used iodinated small molecular contrast agent. And BL-Au NPs can be used as contrast agent for effective CT imaging of zebra fish model. These results suggest the potential utility of BL-Au NPs as a CT imaging contrast agent in clinical CT imaging based diagnosis.

Effect of Gold Nanoparticle Size on Their Properties as Contrast Agents for Computed Tomography

Computed tomography (CT) is one of the most commonly used clinical imaging modalities. There have recently been many reports of novel contrast agents for CT imaging. In particular, the development of gold nanoparticles (AuNP) as CT contrast agents is a topic of intense interest. AuNP have favorable characteristics for this application such as high payloads of contrast generating material, strong X-ray attenuation, excellent biocompatibility, tailorable surface chemistry, and tunable sizes and shapes. However, there have been conflicting reports on the role of AuNP size on their contrast generation for CT. We therefore sought to extensively investigate the AuNP size-CT contrast relationship. In order to do this, we synthesized AuNP with sizes ranging from 4 to 152 nm and capped them with 5 kDa m-PEG. The contrast generation of AuNP of different sizes was investigated with three clinical CT, a spectral photon counting CT (SPCCT) and two micro CT systems. X-ray attenuation was quantified as attenuation rate in Hounsfield units per unit concentration (HU/mM). No statistically significant difference in CT contrast generation was found among different AuNP sizes via phantom imaging with any of the systems tested. Furthermore, in vivo imaging was performed in mice to provide insight into the effect of AuNP size on animal biodistribution at CT dose levels, which has not previously been explored. Both in vivo imaging and ex vivo analysis with inductively coupled plasma optical emission spectroscopy (ICP-OES) indicated that AuNP that are 15 nm or smaller have long blood circulation times, while larger AuNP accumulated in the liver and spleen more rapidly. Therefore, while we observed no AuNP size effect on CT contrast generation, there is a significant effect of size on AuNP diagnostic utility.

Gold-coated plant virus as computed tomography imaging contrast agent.

Chemical modification of the surface of viruses, both the interior and the exterior, imparts new functionalities, that have potential applications in nanomedicine. In this study, we developed novel virus-based nanomaterials as a contrast agent for computed tomography (CT) imaging in vitro. The gold-coated cowpea mosaic virus (Au-CPMV) particles were generated by the electrostatic adsorption of positively charged electrolyte on the virus capsid with the subsequent incubation and reduction of anionic gold complexes. Au-CPMV particles as a CT contrast agent offer a fast scan time (less than 2 min), low cost, and biocompatibility and allow for high-resolution imaging with ca. 150 Hounsfield units (HU). The Au-CPMV surface was further modified allowing for the incorporation of targeting molecules of specific cell types.

CT contrast agent of Platinum nanodendrites: Preliminary study

Platinum nanodendrites (PtNDs) are high-Z nanomaterials (Z=78) that possess a promising potential to be introduced as a novel contrast agent in diagnostic radiology. The objective of this study is to investigate the performance of PtNDs as contrast agent in computed tomography in term of CT number and CNR. PtNDs of different sizes (29, 36, 42, 52 nm) were prepared into final concentration of 1.0 mM in 3 mL syringes. CT scans were performed on PtND samples, distilled water and iodinated contrast agent arranged in phantom. The scans of each samples were conducted at 0.6 mm slice thickness and 80 kVp setting. CT number and contrast to noise ratio (CNR) were measured and calculated. The attenuation property of PtNDs shows size dependent characteristics, as the smallest PtNDs tested (29 nm) shows the lowest CT number (3.73 ± 0.37), followed by 36 nm PtNDs (21.23 ± 0.77), 42 nm (62.77 ± 2.08) and 52 nm (89.33 ± 4.60). CNR quantification reveals that there are no significant different of CNR values for PtNDs of size 29 nm, 36 nm, and 42 nm (around 24.67 ± 0.25), while 52 nm PtNDs sees drop of CNR (20.14 ± 0.57). Compared to iodinated contrast agent, 42 and 52 nm PtNDs show higher CT number, with slightly reduced CNR. This preliminary study suggests that PtNDs have the potential to be applied as contrast agents for CT imaging. The study also demonstrates that the performance of nanomaterial based contrast agent and x-ray attenuation properties are dependent on nanoparticles size and further study is required to elucidate multiparameter involved.

Bi2WO6 Semiconductor Nanoplates for Tumor Radiosensitization through High- Z Effects and Radiocatalysis.

The radioresistance of tumor cells is considered to be an Achilles' heel of cancer radiotherapy. Thus, an effective and biosafe radiosensitizer is highly desired but hitherto remains a big challenge. With the rapid progress of nanomedicine, multifunctional inorganic nanoradiosensitizers offer a new route to overcome the radioresistance and enhance the efficacy of radiotherapy. Herein, poly(vinylpyrrolidone) (PVP)-modified Bi2WO6 nanoplates with good biocompatibility were synthesized through a simple hydrothermal process and applied as a radiosensitizer for the enhancement of radiotherapy for the first time. On the one hand, the high- Z elements Bi ( Z = 83) and W ( Z = 74) endow PVP-Bi2WO6 with better X-ray energy deposition performance and thus enhance radiation-induced DNA damages. On the other hand, Bi2WO6 semiconductors exhibit significant photocurrent and photocatalytic-like radiocatalytic activity under X-ray irradiation, giving rise to the effective separation of electron/hole (e-/h+) pairs and subsequently promoting the generation of cytotoxic reactive oxygen species, especially hydroxyl radicals (•OH). The γ-H2AX and clonogenic assays demonstrated that PVP-Bi2WO6 could efficiently increase cellular DNA damages and colony formations under X-ray irradiation. These versatile features endowed PVP-Bi2WO6 nanoplates with enhanced radiotherapy efficacy in animal models. In addition, Bi2WO6 nanoplates can also serve as good X-ray computed tomography imaging contrast agents. Our findings provide an alternative nanotechnology strategy for tumor radiosensitization through simultaneous radiation energy deposition and radiocatalysis.

Receptor-Mediated and Tumor-Microenvironment Combination-Responsive Ru Nanoaggregates for Enhanced Cancer Phototheranostics.

Although phototherapy has been considered as an emerging and promising technology for cancer therapy, its therapeutic specificity and efficacy are severely limited by nonspecific uptake by normal tissues, tumor hypoxia, and so on. Herein, combination-responsive strategy (CRS) is applied to develop one kind of hyaluronic acid-hybridized Ru nanoaggregates (HA-Ru NAs) for enhanced cancer phototherapy via the reasonable integration of receptor-mediated targeting (RMT) and tumor-microenvironment responsiveness (TMR). In this nanosystem, the HA component endows HA-Ru NAs with RMT characteristic to selectively recognize CD44-overexpressing cancer cells, whereas the Ru nanocomponent makes HA-Ru NAs have TMR therapy activity. Specially, the Ru nanocomponent not only has near-infrared-mediated photothermal and photodynamic functions but also can catalyze H2O2 in tumor tissue to produce O2 for the alleviation of tumor hypoxia and toxic •OH for chemodynamic therapy. Benefitting from these, HA-Ru NAs can be considered as a promising kind of CRS nanoplatforms for synergistic photothermal/photodynamic/chemodynamic therapies of cancer, which will not only effectively improve the phototherapeutic specificity and efficacy but also simplify the therapeutic nanosystems. Meanwhile, HA-Ru NAs can serve as a photoacoustic and computed tomography imaging contrast agent to monitor tumors. Such CRS nanoplatforms hold significant potential in improving therapeutic specificity and efficacy for enhanced cancer phototheranostics.

One-pot bottom-up fabrication of biocompatible PEGylated WS2 nanoparticles for CT-guided photothermal therapy of tumors in vivo

BackgroundTungsten disulfide (WS2), which enjoyed a good potential to be a promising clinical theranostic agent for cancer treatment, is still subject to the tedious synthesis procedure. MethodsHere, we reported a one-pot ‘bottom-up’ hydrothermal strategy for the fabrication of PEGylated WS2 nanoparticles (NPs). The WS2-PEG nanoparticles were characterized systematically. The CT imaging and photothermal therapy against tumor as well as biosafety in vitro and in vivo were also investigated. ResultsThe obtained WS2-PEG NPs enjoyed obvious merits of good solubility and favorable photothermal performance. WS2-PEG NPs exhibited desirable photothermal ablation ability against cancer cells and cancer cell-bearing mice in vitro and in vivo. MTT assay and histological analysis demonstrated the low cytotoxicity and biotoxicity of WS2-PEG NPs, providing a valid biosafety guarantee for the coming biomedical applications. In addition, thanks to the obvious X-ray attenuation of W atom, the WS2-PEG NPs can also be served as a favorable contrast agent for CT imaging of tumors. ConclusionWS2-PEG NPs has enjoyed a good potential to be a promising clinical CT-guided photothermal therapeutic agent against cancers.

Nanoliposomes Co-Encapsulating CT Imaging Contrast Agent and Photosensitizer for Enhanced, Imaging Guided Photodynamic Therapy of Cancer.

Fluorescence (FL) and X-ray computed tomography (CT) imaging-guided photodynamic therapy (PDT) can provide a powerful theranostic tool to visualize, monitor, and treat cancer and other diseases with enhanced accuracy and efficacy.Methods: In this study, clinically approved iodinated CT imaging contrast agent (CTIA) iodixanol and commercially available photosensitizer (PS) meso-tetrakis (4-sulphonatophenyl) porphine (TPPS4) were co-encapsulated in biocompatible PEGylated nanoliposomes (NL) for enhanced anticancer PDT guided by bimodal (FL and CT) imaging.Results: The NL co-encapsulation of iodixanol and TPPS4 (LIT) lead to an increase in singlet oxygen generation by PS via the intraparticle heavy-atom (iodine) effect on PS molecules, as it was confirmed by both direct and indirect measurements of singlet oxygen production. The confocal imaging and PDT of cancer cells were performed in vitro, exhibiting the cellular uptake of TPPS4 formulations and enhanced PDT efficacy of LIT. Meanwhile, bimodal (FL and CT) imaging was also conducted with tumor-bearing mice and the imaging results manifested high-efficient accumulation and retention of LIT in tumors. Moreover, PDT of tumor in vivo was shown to be drastically more efficient with LIT than with other formulations of TPPS4.Conclusion: This study demonstrated that LIT can serve as a highly efficient theranostic nanoplatform for enhanced anticancer PDT guided by bimodal (FL and CT) imaging.