High Relaxivity Values Research Articles

Hollow Bimetallic Complex Nanoparticles for Trimodality Imaging and Photodynamic Therapy In Vivo.

Hollow nanoparticles have received an enormous amount of attention in the field of nanomedicine. Herein, water-soluble hollow bimetallic complex nanoparticles, holmium(III)/iridium(III) bimetallic complex nanoparticles (Ir-Ho HNPs), were fabricated via a coordination assembly. Owing to the special metal-to-ligand charge transfer (MLCT) and the heavy-atom effect of Ir(III) in an iridium complex, Ir-Ho HNPs exhibited an intense phosphorescence and the generation of singlet oxygen (1O2). With the long electron relaxation time and high magnetic moment of Ho(III), Ir-Ho HNPs presented a high longitudinal relaxivity (r2) value (160.0 mM-1 s-1at 7.0 T). Their unique hollow structure resulted in their strong and stable ultrasound signal in an aqueous solution. As a proof of concept, Ir-Ho HNPs have been developed for the phosphorescence imaging and photodynamic therapy for living cells, ultrasound imaging, and high-field magnetic resonance imaging in vivo. Our work opened up an avenue for novel application of an iridium complex in cancer theranostics.

Targeted NIRF/MR dual-mode imaging of breast cancer brain metastasis using BRBP1-functionalized ultra-small iron oxide nanoparticles.

Tumor metastasis to brain is the main clinical manifestation of patients with advanced breast cancer, leading to poor survival prognosis. In order to detect the early incidence of brain metastasis, it is urgent to develop hypersensitive contrast agents for multimode imaging. In this study, PEG-phospholipids coated, a phage play derived peptide, BRBP1 peptide modified ultra-small iron oxide nanoparticles were prepared for targeted NIRF and MR imaging of breast cancer brain metastasis. The nanoparticles showed 10nm core-shell, high relaxivity values and photon emission efficiency in vitro. The nanoparticles offered a T2 contrast imaging effect and near-infrared fluorescent signal enhancement. Compared with control peptide modified nanoparticles, the MR/NIRF imaging signal of BRBP1-modified nanoparticles in tumor tissue was significantly enhanced, which should be induced by the targeting ability of BRBP1 peptide. These results indicated that BRBP1-SPIO@mPEG (DiR) nanoparticles could be applied as an effective targeted delivery system for diagnosis of breast cancer brain metastasis.

Bi-Magnetic Core-Shell CoFe2O4@MnFe2O4 Nanoparticles for In Vivo Theranostics.

In this work, we report the synthesis and characterization of three magnetic nanosystems, CoFe2O4, CoFe2O4@ZnFe2O4, and CoFe2O4@MnFe2O4, which were developed as potential theranostic agents for magnetic hyperthermia and magnetic resonance imaging (MRI). These nanosystems have been thoroughly characterized by X-ray Diffraction (XRD), Transmission Electron Miscroscopy (TEM), Dark Field-TEM (DF-TEM), Vibrating Sample Magnetometry (VSM), and inductive heating, in order to elucidate their structure, morphology, and magnetic properties. The bi-magnetic CoFe2O4@ZnFe2O4 and CoFe2O4@MnFe2O4 nanoparticles (NPs) exhibited a core-shell structure with a mean average particle size of 11.2 ± 1.4 nm and 14.4 ± 2.4 nm, respectively. The CoFe2O4@MnFe2O4 NPs showed the highest specific absorption rate (SAR) values (210–320 W/g) upon exposure to an external magnetic field, along with the highest saturation magnetization (Ms). Therefore, they were selected for functionalization with the PEGylated ligand to make them stable in aqueous media. After the functionalization process, the NPs showed high magnetic relaxivity values and very low cytotoxicity, demonstrating that CoFe2O4@MnFe2O4 is a good candidate for in vivo applications. Finally, in vivo MRI experiments showed that PEGylated CoFe2O4@MnFe2O4 NPs produce high T2 contrast and exhibit very good stealth properties, leading to the efficient evasion of the mononuclear phagocyte system. Thus, these bi-magnetic core-shell NPs show great potential as theranostic agents for in vivo applications, combining magnetic hyperthermia capabilities with high MRI contrast.

In Vivo Positive Magnetic Resonance Imaging Applications of Poly(methyl vinyl ether-alt-maleic acid)-coated Ultra-small Paramagnetic Gadolinium Oxide Nanoparticles.

The study of ultra-small paramagnetic gadolinium oxide (Gd2O3) nanoparticles (NPs) as in vivo positive (T1) magnetic resonance imaging (MRI) contrast agents is one of the most attractive fields in nanomedicine. The performance of the Gd2O3 NP imaging agents depends on the surface-coating materials. In this study, poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) was used as a surface-coating polymer. The PMVEMA-coated paramagnetic ultra-small Gd2O3 NPs with an average particle diameter of 1.9 nm were synthesized using the one-pot polyol method. They exhibited excellent colloidal stability in water and good biocompatibility. They also showed a very high longitudinal water proton spin relaxivity (r1) value of 36.2 s−1mM−1 (r2/r1 = 2.0; r2 = transverse water proton spin relaxivity) under a 3.0 tesla MR field which is approximately 10 times higher than the r1 values of commercial molecular contrast agents. High positive contrast enhancements were observed in in vivo T1 MR images after intravenous administration of the NP solution sample, demonstrating its potential as a T1 MRI contrast agent.

Peptide-Based Soft Hydrogels Modified with Gadolinium Complexes as MRI Contrast Agents.

Poly-aromatic peptide sequences are able to self-assemble into a variety of supramolecular aggregates such as fibers, hydrogels, and tree-like multi-branched nanostructures. Due to their biocompatible nature, these peptide nanostructures have been proposed for several applications in biology and nanomedicine (tissue engineering, drug delivery, bioimaging, and fabrication of biosensors). Here we report the synthesis, the structural characterization and the relaxometric behavior of two novel supramolecular diagnostic agents for magnetic resonance imaging (MRI) technique. These diagnostic agents are obtained for self-assembly of DTPA(Gd)-PEG8-(FY)3 or DOTA(Gd)-PEG8-(FY)3 peptide conjugates, in which the Gd-complexes are linked at the N-terminus of the PEG8-(FY)3 polymer peptide. This latter was previously found able to form self-supporting and stable soft hydrogels at a concentration of 1.0% wt. Analogously, also DTPA(Gd)-PEG8-(FY)3 and DOTA(Gd)-PEG8-(FY)3 exhibit the trend to gelificate at the same range of concentration. Moreover, the structural characterization points out that peptide (FY)3 moiety keeps its capability to arrange into β-sheet structures with an antiparallel orientation of the β-strands. The high relaxivity value of these nanostructures (~12 mM−1·s−1 at 20 MHz) and the very low in vitro cytotoxicity suggest their potential application as supramolecular diagnostic agents for MRI.

Porous versus Dense ‐ Effect of Silica Coating on Contrast Enhancement of Iron Carbide Nanoparticles in T2‐Weighted Magnetic Resonance Imaging

AbstractMagnetic nanoparticles development is an intense subject in various biomedical applications. Among these applications, magnetic nanoparticles as contrast agents are of special interest for improving the diagnostic accuracy of magnetic resonance imaging (MRI). We report here the synthesis of magnetic iron carbide nanoparticles and their stabilization in aqueous media. The challenge of achieving phase transfer of hydrophobic iron carbide nanoparticles to hydrophilic media was addressed by silica shell. Silica coated iron carbide nanoparticles were fabricated with both mesoporous and dense silica shells followed by investigating the impact of such a coating on their performance as T2‐negative contrast agents in MRI. The crystalline structure of silica coated iron carbide nanoparticles was confirmed via X‐ray diffraction (XRD) analysis. Fourier transform infrared spectroscopy (FTIR) demonstrated formation of the silica coating and transmission electron microscopy (TEM) confirmed the core@shell morphology of silica coated iron carbide nanoparticles. Mesoporous and dense silica coated iron carbide nanoparticles exhibited high transverse relaxivity values of 457 and 365 mM−1s−1, respectively. The enhanced MRI efficiency obtained from the silica coated iron carbide nanoparticles highlights these core@shell structures as promising negative contrast agents. Based on the results, the nature of silica coating both in porous or dense forms has a significant effect on water relaxivity which makes the iron carbide@mesoporous silica nanoparticles highly efficient T2 contrast agents.

Silica Coated Iron/Iron Oxide Nanoparticles as a Nano-Platform for T2 Weighted Magnetic Resonance Imaging.

The growing concern over the toxicity of Gd-based contrast agents used in magnetic resonance imaging (MRI) motivates the search for less toxic and more effective alternatives. Among these alternatives, iron–iron oxide (Fe@FeOx) core-shell architectures have been long recognized as promising MRI contrast agents while limited information on their engineering is available. Here we report the synthesis of 10 nm large Fe@FeOx nanoparticles, their coating with a 11 nm thick layer of dense silica and functionalization by 5 kDa PEG chains to improve their biocompatibility. The nanomaterials obtained have been characterized by a set of complementary techniques such as infra-red and nuclear magnetic resonance spectroscopies, transmission electron microscopy, dynamic light scattering and zetametry, and magnetometry. They display hydrodynamic diameters in the 100 nm range, zetapotential values around −30 mV, and magnetization values higher than the reference contrast agent RESOVIST®. They display no cytotoxicity against 1BR3G and HCT116 cell lines and no hemolytic activity against human red blood cells. Their nuclear magnetic relaxation dispersion (NMRD) profiles are typical for nanomaterials of this size and magnetization. They display high r2 relaxivity values and low r1 leading to enhanced r2/r1 ratios in comparison with RESOVIST®. All these data make them promising contrast agents to detect early stage tumors.

Aqueous solutions of triblock copolymers used as the media affecting the magnetic relaxation properties of gadolinium ions trapped by metal-oxide nanostructures

The present work introduces the optimization of the oxidative degradation, complex formation and aggregation of the water-soluble metal oxide nanostructures (the so-called keplerates) [{W6O21(H2O)5(OAc)0.5}12{Mo2O4(OAc)}30]48− (W72Mo60), [{Mo6O21(H2O)3(SO4)}12(VO)30(H2O)20]26− (Mo72V30), and [{Mo6O21}12Fe30(OAc)12{Mo2O7(H2O)}2{H2Mo2O8(H2O)}(H2O)91] (Mo72Fe30) in aqueous solutions containing Gd3+ ions and triblock copolymers, which can be used as a tool to enhance magnetic relaxivity of the gadolinium-bound nanostructures. The particularly significant enhancement in the magnetic relaxivity of the Gd3+ ions bound with W72Mo60 versus Mo72Fe30/V30 is due to the more convenient size of the external pores in the keplerate framework, which are the binding sites for Gd3+ aqua ions. The structure of the W72Mo60 keplerate is also responsible for the high stabilities of its gadolinium complexes against oxidative degradation in the solutions. The aggregation of the gadolinium-bound W72Mo60 keplerates controlled by the Gd:keplerate molar ratio is a factor in addition to the structure affecting the relaxivity. The assembly of the gadolinium-bound keplerates with the triblock copolymers enhances the relaxivity values by limiting the size of the aggregates, while the relaxivity of the molecular complexes is insignificantly affected by the assembly with the triblock copolymers. The gadolinium complexes exhibiting competitively high magnetic relaxivity values, coupled with their high chemical stability and low cytotoxicity, are introduced herein as the result of the structural optimization, both on molecular and supramolecular levels.

One-pot Synthesis of PEGylated Gd-based Nanoparticles as High-performance and Biocompatibility Contrast Agents for T1-Weighted Magnetic Resonance Imaging In vivo

Polyethylene glycol modified(PEGylated) NaGdF4(PEG-NaGdF4) nanoparticles as a novel T1-weighted magnetic resonance imaging(MRI) contrast agent was successfully constructed by a one-pot hydrothermal synthesis method. Because of the functionalization of PEG, the nanoprobes had excellent dispersity, excellent stability and high biocompatibility. More importantly, the as-prepared PEG-NaGdF4 nanoprobes revealed the high longitudinal relaxivity value and prominent T1-weighted MRI contrast performance, which was superior to the commercial MRI contrast agents. With the facile synthesis, excellent dispersity, outstanding stability, remarkable contrast performance and high biocompatibility, the PEGylated NaGdF4 nanoparticles brought more opportunities to the new generation of nanoparticulate-based T1-weighted MRI contrast agents in clinic.

1H NMR Relaxometric Analysis of Paramagnetic Gd2O3:Yb Nanoparticles Functionalized with Citrate Groups

Gd2O3 nanoparticles doped with different amount of Yb3+ ions and coated with citrate molecules were prepared by a cheap and fast co-precipitation procedure and proposed as potential “positive” contrast agents in magnetic resonance imaging. The citrate was used to improve the aqueous suspension, limiting particles precipitation. The relaxometric properties of the samples were studied in aqueous solution as a function of the magnetic field strength in order to evaluate the interaction of the paramagnetic ions exposed on the surface with the water molecules in proximity. The nanoparticles showed high relaxivity values at a high magnetic field with respect to the clinically used Gd3+-chelates and comparable to those of similar nanosytems. Special attention was also addressed to the investigation of the chemical stability of the nanoparticles in biological fluid (reconstructed human serum) and in the presence of a chelating agent.

Synthesis, Magnetic Properties, and Relaxivity of CoFe@C and NiFe@C Nanocomposites

Core–shell CoFe@C and NiFe@C nanocomposites were prepared by gas-condensation synthesis. CoFe@C and NiFe@C particles had bcc and fcc cores, respectively. The treatment of these nanocomposites with hydrochloric acid revealed that they are more chemically stable than Fe@C composites. The maximum specific magnetization of CoFe@C and NiFe@C nanocomposites at room temperature in the field with a strength of 27 kOe was 125 and 58 G cm3/g, respectively. The processes of longitudinal and transverse relaxation of nuclear proton spins of aqueous suspensions of nanocomposites in various magnetic fields (0.5, 1, and 2 kOe) were studied. NiFe@C and CoFe@C nanocomposites have high transverse relaxivity values and can be used as magnetic markers for detection of low concentrations of bioobjects by NMR relaxometry.

Facile synthesis of dual-functional nanoparticles co-loaded with ZnPc/Fe3O4 for PDT and magnetic resonance imaging

In this work, a class of dual-functional nanoparticles (NPs) were facilely prepared from ZnPc and Fe3O4 NPs for photodynamic therapy (PDT) and magnetic resonance imaging (MRI). The as-synthesized NPs were investigated in terms of size, morphology, zeta potential, biocompatibility, optical and magnetic properties respectively. The aggregation degree of ZnPc in hybrid NPs was found to be considerably meliorated with the presence of Fe3O4 NPs, corresponding to higher 1O2 generation rate. Based on the dual-functional NPs, MRI and in vitro PDT was carried out, respectively, yielding a high r2 relaxivity value of 152.9 mM−1 s−1 and strong photocytotoxicity. Given the facility of synthesis, such a strategy can be applied to prepare other multifunctional NPs by introducing other small-sized NPs, such as Au NPs (photothermal), quantum dots (fluorescence imaging), etc.

Preparation of gadolinium doped carbon dots for enhanced MR imaging and cell fluorescence labeling

Gadolinium doped carbon dots (Gd-CDs) were prepared as a dual-modal imaging agent for enhanced MR imaging and cell fluorescence imaging. The Gd-CDs were synthesized via one-step solvent free technique with Gd-DTPA and l-arginine as the Gd and carbon sources with a quantum yield of 57.78%. The Gd-CDs exhibited good crystal structure, excellent aqueous dispersity, high colloidal stability, intense fluorescence and low cytotoxicity. The bio-TEM images revealed that the Gd-CDs could be easily internalized by cancer cells and escape from the endosomes. Furthermore, the Gd-CDs demonstrated wonderful multi-color fluoresence cell labeling ability at various excitation wavelength and much better MR contrast effect compared with commercial Gd-DTPA with a high r1 relaxivity value 6.27 mM−1s−1. In addition, Gd-CDs exhibited brighter MR signal than Gd-DTPA in the animal MR imaging test. Finally, the Gd-CDs also indicated low long-term toxicity by the serum biochemistry analysis. Thus, these results indicated that Gd-CDs would be an excellent dual-modal imaging probe for enhanced MR imaging and fluorescence imaging.

Synthesis of 68Ga Core-doped Iron Oxide Nanoparticles for Dual Positron Emission Tomography /(T1)Magnetic Resonance Imaging.

Here, we describe a microwave synthesis to obtain iron oxide nanoparticles core-doped with 68Ga. Microwave technology enables fast and reproducible synthetic procedures. In this case, starting from FeCl3 and citrate trisodium salt, iron oxide nanoparticles coated with citric acid are obtained in 10 min in the microwave. These nanoparticles present a small core size of 4.2 ± 1.1 nm and a hydrodynamic size of 7.5 ± 2.1 nm. Moreover, they have a high longitudinal relaxivity (r1) value of 11.9 mM-1·s-1 and a modest transversal relaxivity value (r2) of 22.9 mM-1·s-1, which results in a low r2/r1 ratio of 1.9. These values enable positive contrast generation in magnetic resonance imaging (MRI) instead of negative contrast, commonly used with iron oxide nanoparticles. In addition, if a 68GaCl3 elution from a 68Ge/68Ga generator is added to the starting materials, a nano-radiotracer doped with 68Ga is obtained. The product is obtained with a high radiolabeling yield (> 90%), regardless of the initial activity used. Furthermore, a single purification step renders the nano-radiomaterial ready to be used in vivo.

Polyhydroxybutyrate-co-hydroxyvalerate copolymer modified graphite oxide based 3D scaffold for tissue engineering application

In this study, we have fabricated the PHBV functionalized graphite oxide using freeze drying technique, followed by ‘in situ’ pay loading of Fe3O4 nanoparticles onto the hydrophobic plate of the composite basal plane; thereby, mechanically and thermally stable, bio-imaging Fe3O4/GO-g-PHBV composites have been developed. The synthesis of Fe3O4/GO-g-PHBV composite was confirmed by field emission SEM and TEM analyses, X-ray diffraction and Fourier transform infrared spectroscopy. The wrapping of PHBV copolymer into the graphene layers was investigated by atomic force microscopy and Raman spectral analyses which provided the shifting of the 2D band with low signal intensity in the range of 2600–3000 cm−1. The bactericidal activities of the Fe3O4/GO-g-PHBV composite films were found to exhibit more efficiency against Gram-negative bacteria strains compared to Gram-positive strains. In vibrating sample magnetometer (VSM) analysis, the zero value of coercivity revealed the super-paramagnetic nature of the Fe3O4/GO-g-PHBV composites. The Phantom agar magnetic resonance imaging analysis revealed the efficiency of Fe3O4 nanoparticles as a negative contrast (T2 contrast) along with higher relaxivity value. The significant fibroblast cell (NIH 3T3) adhesion and proliferation (85%) on the Fe3O4/GO-g-PHBV composite surface indicated the physiological and biocompatible stability of that composite along with the presence of large π conjugated aromatic domain.

One-pot embedding of iron oxides and Gd(III) complexes into silica nanoparticles—Morphology and aggregation effects on MRI dual contrasting ability

The present work introduces one-pot synthetic route to join ultra-small iron oxides (6 nm) with Gd(III) complexes in small (∼30 nm) silica nanoparticles with high longitudinal and transverse relaxivity values (r1 = 34.7 mM−1 s−1 and r2 = 64.7 mM−1 s−1 at 0.47 T). The design of the nanoparticles is based on the core-shell morphology, where the Gd(III) complexes were doped into the exterior silica layer. The doping mode is the reason for an efficient interfacial hydration and the small suppressing of r1 by iron oxides. The measurements on the whole body scanner at 1.5 T confirm the high contrasting abilities of T1 (Gd) and T2 (iron oxide) components in the nanoparticles. Poor aggregation behavior of the nanoparticles in water is due to high electrokinetic potential value (−78 mV). Greater aggregation of the nanoparticles in the buffer solutions of bovine serum albumin enhances the disturbing effect of iron oxides on the longitudinal relaxation and facilitates the transverse relaxation. The higher surface activity of the nanoparticles results in their greater cytotoxicity versus the silica coated iron oxides, although the cytotoxicity is low in the concentration range which is within the region of interest for MRI technique.

Ultra-small Albumin Templated Gd/Ru Composite Nanodots for In Vivo Dual modal MR/Thermal Imaging Guided Photothermal Therapy.

Multifunctional theranostic nanoagents which realize precise diagnosis and treatment of tumors are attracting increasing interests in recent years. However, efficient and controlled synthesis of ultra-small noble metal nanoagents remains a challenge. Here, monodisperse Gd/Ru@BSA nanodots (GRBNDs) are successfully fabricated via a totally "green", "one-pot" protocol for in situ reduction of Ru(III) and biomineralization of Gd(III) in the presence of albumin. The as-prepared nanoagent possesses the features of being ultra small in size (≈6.7 nm), having strong colloidal stability, and thermal stability as well as high photothermal conversion efficiency (η = 50.7%). As expected, the GRBNDs achieve a significant efficacy of anticancer therapy under LASER activation both in vitro and in vivo. It also exhibits superior T1 -weighted magnetic resonance (MR) imaging ability due to its high longitudinal relaxivity value (r1 = 10.98 × 10-3 m-1 s-1 ). Moreover, it is demonstrated to be renal clearable with negligible systemic toxicity. This work highlights a straightforward and repeatable approach for synthesizing highly effective and multifunctional noble metal nanoagent of great clinical promising for cancer theranostics.

Synthesis, Characterization, and Biodistribution of a Dinuclear Gadolinium Complex with Improved Properties as a Blood Pool MRI Agent

A dinuclear gadolinium(III) chelate containing two moieties of diethylenetriaminepentaacetic acid (DTPA), covalently conjugated to an analogue of deoxycholic acid, was synthesized and thoroughly characterized. A full relaxometric analysis was carried out, consisting of 1) the acquisition of nuclear magnetic resonance dispersion (NMRD) profiles in various media; 2) the study of binding affinity to serum albumin; 3) the measurement of 17 O transverse relaxation rate versus temperature, and 4) a transmetallation assay. In vivo biodistribution MRI studies at 1 T and blood pharmacokinetics assays were carried out in comparison with Gd-DTPA (Magnevist) and gadocoletic acid trisodium salt (B22956/1), two well-known Gd complexes that share the same chelating cage and the same deoxycholic acid residue of the Gd complex investigated herein ((GdDTPA)2 -Chol). High affinity for plasma protein and, in particular, the availability of more than one binding site, allows the complex to reach a fairly high relaxivity value in plasma (∼20 mm-1 s-1 , 20 MHz, 310 K) as well as to show unexpectedly enhanced properties of blood pooling, with an elimination half-life in rats approximately seven times longer than that of B22956/1.

A New Bis(aquated) High Relaxivity Mn(II) Complex as an Alternative to Gd(III)-Based MRI Contrast Agent.

Disclosed here are a piperazine, a pyridine, and two carboxylate groups containing pentadentate ligand H2pmpa and its corresponding water-soluble Mn(II) complex (1). DFT-based structural optimization implied that the complex had pentagonal bipyramidal geometry where the axial positions were occupied by two water molecules, and the equatorial plane was constituted by the ligand ON3O donor set. Thus, a bis(aquated) disc-like Mn(II) complex has been synthesized. The complex showed higher stability compared with Mn(II)-EDTA complex [log KMnL = 14.29(3)] and showed a very high r1 relaxivity value of 5.88 mM-1 s-1 at 1.41 T, 25 °C, and pH = 7.4. The relaxivity value remained almost unaffected by the pH of the medium in the range of 6-10. Although the presence of 200 equiv of fluoride and bicarbonate anions did not affect the relaxivity value appreciably, an increase in the value was noticed in the presence of phosphate anion due to slow tumbling of the complex. Cell viability measurements, as well as phantom MR images using clinical MRI imager, consolidated the possible candidature of complex 1 as a positive contrast agent.

One-pot synthesis of albumin-gadolinium stabilized polypyrrole nanotheranostic agent for magnetic resonance imaging guided photothermal therapy

Theranostic agents with perfect properties are needed urgently for the development of imaging guided photothermal therapy (PTT). In this work, Gd-integrated polypyrrole nanotheranostic agent (PPy@BSA-Gd) was successfully built through selecting bovine serum albumin (BSA) as both stabilizers for polymerization and biomimetic mineralization in "one pot". The obtained PPy@BSA-Gd possessed high stability and excellent photothermal property. Besides, relevant cellular assays indicated that PPy@BSA-Gd had fantastic cytocompatibility which could be further internalized by cancer cells. Due to their high longitudinal relaxivity value (r1 = 10.203 mM−1 s−1), PPy@BSA-Gd could serve as considerable probe for T1-weighted magnetic resonance imaging (MRI). After tail vein injection of PPy@BSA-Gd, the MR signal of tumor section exhibited a time-dependent increase, indicating effective tumor accumulation of PPy@BSA-Gd. Notably, when exposed to 808 nm laser, the tumor growth of PPy@BSA-Gd treated mice could be inhibited by photothermal ablation successfully. All the results demonstrated the well-designed PPy@BSA-Gd have the potential for tumor diagnose and photothermal therapy.