High Penetration Depth Research Articles

Linear shaped-charge jet optimization using machine learning methods

Linear shaped charges are used to focus energy into rapidly creating a deep linear incision. The general design of a shaped charge involves detonating a confined mass of high explosive (HE) with a metal-lined concave cavity on one side to produce a high velocity jet for the purpose of striking and penetrating a given material target. This jetting effect occurs due to the interaction of the detonation wave with the cavity geometry, which produces an unstable fluid phenomenon known as the Richtmyer–Meshkov instability and results in the rapid growth of a long narrow jet. We apply machine learning and optimization methods to hydrodynamics simulations of linear shaped charges to improve the simulated jet characteristics. The designs that we propose and investigate in this work generally involve modifying the behavior of the detonation waves prior to interaction with the liner material. These designs include the placement of multiple detonators and the use of metal inclusions within the HE. We are able to produce a linear shaped-charge design with a higher penetration depth than the baseline case that we consider and accomplish this using the same amount of or less HE.

Spray characteristics of a liquid fuel jet in a tandem backward-facing step cavity in supersonic flow

The influences of the backward-facing step and injection schemes on the spray characteristics of a liquid jet in a tandem backward-facing step cavity were investigated experimentally using high-speed photography and Schlieren techniques under a Mach 2.0 supersonic crossflow for the first time. The instantaneous structures of the spray and wave structures of the air-flow field were accurately captured by the high temporal resolution experimental technology. It is found that exist complex wave structures in the tandem backward-facing step cavity. A dimensionless spray factor was defined to describe the concentration of spray inside the cavity qualitatively. As a result, it is revealed that for the short backward-facing step cavity, the injection scheme near the upstream inlet has a higher penetration depth but a lower spray distribution, while the injection scheme near the cavity has a more spray distribution. For the long backward-facing step cavity, the injection scheme near the upstream inlet also has a higher penetration depth and the injection scheme near the sharp corner of the backward-facing step has a more sufficient spray distribution. The long backward-facing step cavity-based combustor with the upstream wall transverse injection is an optimized injection scheme to both improve penetration and spray distribution inside the cavity. Finally, a penetration depth formula is proposed to explain the spray distribution behaviors in a tandem backward-facing step cavity.

Effect of TIG and activated flux TIG welding processes on weld bead geometry, microstructure, and hardness of SAF 2507 grade super duplex stainless steel joints

Tungsten inert gas (TIG) welding is frequently used to fabricate super duplex stainless steel weldments due to its superior mechanical qualities and attractive appearance in contrast with other arc welding techniques. The broad use of TIG welding remains constrained despite all of its advantages. Thus, the process of activated flux tungsten inert gas (A-TIG) welding is created. In the current study, ATIG welding with different oxide fluxes is used to execute bead-on-plate welding on 6 mm thick super duplex (SS) SAF 2507 grade. The TIG and ATIG processes are used for bead-on-plate welding, and the macrostructure, microstructure, and mechanical features of super DSS weld beads are analysed. When different oxide fluxes are used, the A-TIG technique achieves a greater depth of penetration and a narrower weld bead width than the standard TIG process. SiO2 flux with ATIG welding gives the highest depth of penetration (5.42 mm) among all other fluxes used. Also, A-TIG welding using SiO2 flux has a finer grain structure and a higher hardness value than other fluxes. The primary microstructure in the A-TIG weld zone was austenitic, but delta ferrite was still present.

An ultrasound-activatable platinum prodrug for sono-sensitized chemotherapy

Despite the great success achieved by photoactivated chemotherapy, eradicating deep tumors using external sources with high tissue penetration depth remains a challenge. Here, we present cyaninplatin, a paradigm of Pt(IV) anticancer prodrug that can be activated by ultrasound in a precise and spatiotemporally controllable manner. Upon sono-activation, mitochondria-accumulated cyaninplatin exhibits strengthened mitochondrial DNA damage and cell killing efficiency, and the prodrug overcomes drug resistance as a consequence of combined effects from released Pt(II) chemotherapeutics, the depletion of intracellular reductants, and the burst of reactive oxygen species, which gives rise to a therapeutic approach, namely sono-sensitized chemotherapy (SSCT). Guided by high-resolution ultrasound, optical, and photoacoustic imaging modalities, cyaninplatin realizes the overall theranostics of tumors in vivo with superior efficacy and biosafety. This work highlights the practical utility of ultrasound to precisely activate Pt(IV) anticancer prodrugs for the eradication of deep tumor lesions and broadens the biomedical uses of Pt coordination complexes.

2D Ultrathin Iron Doped Bismuth Oxychloride Nanosheets with Rich Oxygen Vacancies for Enhanced Sonodynamic Therapy.

Sonodynamic therapy (SDT) combines ultrasound and sonosensitizers to produce toxic reactive oxygen species (ROS) for cancer cell killing. Due to the high penetration depth of ultrasound (US), SDT breaks the depth penetration barrier of conventional photodynamic therapy for the treatment of deeply seated tumors. A key point to enhance the therapeutic efficiency of SDT is the development of novel sonosensitizers with promoted ability for ROS production. Herein, ultrathin Fe-doped bismuth oxychloride nanosheets with rich oxygen vacancies and bovine serum albumin coating on surface are designed as piezoelectric sonosensitizers (BOC-Fe NSs) for enhanced SDT. The oxygen vacancies of BOC-Fe NSs provide electron trapping sites to promote the separation of e- -h+ from the band structure, which facilitates the ROS production under the ultrasonic waves. The piezoelectric BOC-Fe NSs create a built-in field and the bending bands, further accelerating the ROS generation with US irradiation. Furthermore, BOC-Fe NSs can induce ROS generation by a Fenton reaction catalyzed by Fe ion with endogenous H2 O2 in tumor tissues for chemodynamic therapy. The as-prepared BOC-Fe NSs efficiently inhibited breast cancer cell growth in both in vitro and in vivo tests. The successfully development of BOC-Fe NSs provides a new nano-sonosensitiser option for enhanced SDT for cancer therapy.

Lanthanide‐doped rare earth nanoparticles for near‐infrared‐II imaging and cancer therapy

AbstractThe optical nanoprobes with emissions in the second near‐infrared window (NIR‐II, 1000–1700 nm) show low tissue autofluorescence and photon scattering; therefore, they provide high spatial resolution and acceptable tissue penetration depth. These advantages make them appropriate for in vivo applications, including bioimaging, NIR‐II triggered disease therapy, and even on‐site efficacy monitoring. Among the various developed NIR‐II fluorescence probes, lanthanide‐doped nanoparticles (LDNPs) exhibit high photo stability and narrow emission bandwidths with long photoluminescence lifetimes and low cytotoxicity; therefore, they have been widely studied in the biomedical field. This review summarizes the typical compositions and optical properties of recently developed NIR‐II emitting LDNPs. Their applications in in vivo NIR‐II bioimaging and cancer therapy are reviewed. The perspectives and challenges of NIR‐II LDNPs are also discussed.

Caspase-3-Responsive Fluorescent/Photoacoustic Imaging of Tumor Apoptosis.

Caspase-3 is an essential executor in apoptosis, and its activation has been regarded as a biomarker of cell apoptosis. The development of Caspase-3-responsive multimodal probes is a promising research prospect. Fluorescent/photoacoustic (FL/PA) imaging has attracted considerable attention due to the high sensitivity of FL as well as the high spatial resolution and penetration depth of PA. To our knowledge, there has been no tumor-targeted FL/PA probe to monitor the activity of Caspase-3 in vivo. Therefore, we developed a tumor-targeted FL/PA probe (Bio-DEVD-HCy) for Caspase-3-responsive imaging of tumor apoptosis. Ac-DEVD-HCy without tumor-targeted biotin is used as a control probe. In vitro experiments indicated that Bio-DEVD-HCy is superior to Ac-DEVD-HCy because of the higher kinetic parameter of Bio-DEVD-HCy in comparison to Ac-DEVD-HCy. Cell and tumor imaging results suggested that Bio-DEVD-HCy could enter and accumulate in tumor cells with higher FL/PA signal with the help of tumor-targeted biotin. In detail, Bio-DEVD-HCy or Ac-DEVD-HCy could image apoptotic tumor cells with 4.3-fold or 3.5-fold FL enhancement and 3.4-fold or 1.5-fold PA enhancement. Bio-DEVD-HCy or Ac-DEVD-HCy could image tumor apoptosis with 2.5-fold or 1.6-fold FL enhancement and 4.1-fold or 1.9-fold PA enhancement. We envision that Bio-DEVD-HCy will be applied for FL/PA imaging of tumor apoptosis in clinical settings.

Evolution of the microstructure of superfine grain graphites under thermal oxidation

Nuclear graphite is used as a moderator and structural material in a number of Gen-IV reactor designs, such as the (Very) High Temperature Reactors. Chronic or acute thermal oxidation affects the mechanical properties of the graphite components and the impact on the structural integrity of the core depends on the evolution of the microstructure during oxidation.This study qualitatively examined the microstructure of four superfine grain graphites using polarised and fluorescent optical microscopy. These graphites had similar physical properties but notable differences in the oxidation rate at 700 °C. Using fluorescent microscopy, it was possible to distinguish between open and closed porosity in graphite, which is useful in understanding the progression of thermal oxidation and penetration depth. Based on the samples in this work, fine open and closed porosity may be linked to increased surface oxidation and relatively high oxidation rate, whereas high penetration depth may be linked to relatively low open porosity consisting mainly of large pores. Fairly large domains of coherent crystallite orientation, perhaps due to the presence of agglomerates, may also indicate lower oxidation rates at 700 °C.This paper demonstrated that fluorescent microscopy combined with image analysis, is a useful tool in understanding the progression of thermal oxidation and the corresponding effect on the microstructure.

Graphene Implanted Shape Memory Polymers with Dielectric Gene Dominated Highly Efficient Microwave Drive

AbstractMicrowave‐driven strategy shows many advantages including selective energization, uniform heating, and high penetration depth, which is a hot topic in wireless actuators. Understanding microwave stimulus‐response mechanisms is the key to developing universal construction strategies for advanced microwave‐driven actuators. Herein, reduced graphene oxide (rGO) with specified dielectric genes and thermal properties is implanted into the shape memory polymer, liquid crystal elastomer (LCE) as an example, to construct soft, reversible, and sensitive microwave actuators. Based on the analysis of microstructure and dielectric properties, LCE‐rGO composites exhibit excellent polarization relaxation‐dominated dielectric loss and electromagnetic (EM) energy conversion ability. The maximum dielectric loss factor (ε″) and loss tangent (tan δe) of LCE‐rGO are dramatically increased by 216% and 87.5% compared to pure LCE, respectively, and the optimum apparent energy harvest efficiency is 19.4 times higher than that of LCE. In addition, the implantation of rGO significantly lowers the microwave actuation threshold of LCE‐rGO composites and reinforces their stimulus‐response capacity. Response time under 750 W microwave irradiation of LCE‐rGO is shortened to <10s. These findings can provide a solid basis for the design and fabrication of highly efficient microwave stimuli‐responsive polymers and enlighten a new approach to wireless actuated smart devices.

Nanoengineered sonosensitive platelets for synergistically augmented sonodynamic tumor therapy by glutamine deprivation and cascading thrombosis.

Ultrasound (US)-activated sonodynamic therapy (SDT) stands for a distinct antitumor modality because of its attractive characteristics including intriguing noninvasiveness, desirable safety, and high tissue penetration depth, which, unfortunately, suffers from compromised therapeutic efficacy due to cancer cell-inherent adaptive mechanisms, such as glutathione (GSH) neutralization response to reactive oxygen species (ROS), and glutamine addictive properties of tumors. In this work, we developed a biological sonosensitive platelet (PLT) pharmacytes for favoring US/GSH-responsive combinational therapeutic of glutamine deprivation and augmented SDT. The amino acid transporter SLC6A14 blockade agent α-methyl-DL-tryptophan (α-MT)-loaded and MnO2-coated porphyrinic metal-organic framework (MOF) nanoparticles were encapsulated in the PLTs through the physical adsorption of electrostatic attraction and the intrinsic endocytosis of PLTs. When the sonosensitive PLT pharmacytes reached tumor sites through their natural tendencies to TME, US stimulated the PLTs-loaded porphyrinic MOF to generate ROS, resulting in morphological changes of the PLTs and the release of nanoparticles. Subsequently, intracellular high concentration of GSH and extracellular spatio-temporal controlled US irradiation programmatically triggered the release of α-MT, which enabled the synergistically amplified SDT by inducing amino acid starvation, inhibiting mTOR, and mediating ferroptosis. In addition, US stimulation achieved the targeted activation of PLTs at tumor vascular site, which evolved from circulating PLTs to dendritic PLTs, effectively blocking the blood supply of tumors through thrombus formation, and revealing the encouraging potential to facilitate tumor therapeutics.

Photoacoustic digital brain and deep-learning-assisted image reconstruction

Photoacoustic tomography (PAT) is a newly developed medical imaging modality, which combines the advantages of pure optical imaging and ultrasound imaging, owning both high optical contrast and deep penetration depth. Very recently, PAT is studied in human brain imaging. Nevertheless, while ultrasound waves are passing through the human skull tissues, the strong acoustic attenuation and aberration will happen, which causes photoacoustic signals’ distortion. In this work, we use 180 T1 weighted magnetic resonance imaging (MRI) human brain volumes along with the corresponding magnetic resonance angiography (MRA) brain volumes, and segment them to generate the 2D human brain numerical phantoms for PAT. The numerical phantoms contain six kinds of tissues, which are scalp, skull, white matter, gray matter, blood vessel and cerebrospinal fluid. For every numerical phantom, Monte-Carlo based optical simulation is deployed to obtain the photoacoustic initial pressure based on optical properties of human brain. Then, two different k-wave models are used for the skull-involved acoustic simulation, which are fluid media model and viscoelastic media model. The former one only considers longitudinal wave propagation, and the latter model takes shear wave into consideration. Then, the PA sinograms with skull-induced aberration is taken as the input of U-net, and the skull-stripped ones are regarded as the supervision of U-net to train the network. Experimental result shows that the skull’s acoustic aberration can be effectively alleviated after U-net correction, achieving conspicuous improvement in quality of PAT human brain images reconstructed from the corrected PA signals, which can clearly show the cerebral artery distribution inside the human skull.

Synthesis and luminescent properties of ZnWO4: Cr3+ nanoparticles for NIR-II fluorescence imaging

Fluorescence imaging is of paramount importance in the health and medical aspect, especially for emission in second near-infrared window, where high-resolution deep-tissue imaging can be achieved. Herein, ZnWO4: Cr3+ nanoparticles (NPs) with broadband NIR-II emission were synthesized by a facile solvothermal+calcination method. It is found that Cr3+-doping have no obvious effect of ZnWO4 phase, and the particles of as-prepared NPs are of mono-dispersed cube-shape with average size of ∼100 nm. At optimal 520 nm excitation, the as-synthesized ZnWO4: Cr3+ NPs exhibit an efficient NIR emission peaking at 987 nm and EQE of 4.03% with FWHM of 212 nm. The ZnWO4: Cr3+ NPs possess excellent stability, good biocompatibility and high brightness. NIR-II imaging with high penetration depth and micron spatial resolution was achieved on a mice model. To sum up, our work indicates that ZnWO4: Cr3+ NPs has great application potential as fluorescent agent for NIR-II bio-imaging.

Carbon dots-mediated synthesis of gold nanodendrites with extended absorption into NIR-II window for in vivo photothermal therapy

BackgroundPhotothermal therapy (PTT) in the second near-infrared (NIR-II) window has attracted extensive attention due to the benefits in high maximum permissible exposure and penetration depth. Current photothermal agents generally show a broadband absorption accompanied by a gradual attenuation of absorption in the NIR-II window, leading to poor effect of PTT. It remains a great challenge to gain photothermal agents with strong and characteristic absorption in NIR-II regions. To overcome this problem, based on carbon dots (CDs)-mediated growth strategy, we proposed a simple and feasible approach to prepare plasmonic gold nanodendrites (AuNDs) with NIR-II absorption to enhance the therapeutic effect of PTT.ResultsBy rationally regulating the size and branch length of AuNDs, the AuNDs exhibited a broadband absorption from 300 to 1350 nm, with two characteristic absorption peaks located at 1077 and 1265 nm. The AuNDs demonstrated desired optical photothermal conversion efficiency (38.0%), which was further applied in NIR-II photoacoustic imaging (PAI) and PTT in human colon cancer cells (HCT 116)-tumor-bearing mice model. The tumor cells could be effectively eliminated in vivo under 1064 nm laser irradiation by the guidance of PAI.ConclusionsWe reported a simple but powerful synthetic method to obtain the unique AuNDs with strong and characteristic absorption peaks in the NIR-II window. This study provides a promising solution to tuning the growth of nanoparticles for bioimaging and phototherapy in the NIR-II window.Graphical

Effect of different final irrigation agitation techniques on root canal dentin tubule penetration of nanoparticle calcium hydroxide dressing.

This study is aimed to assess the efficacy of different final irrigation agitation techniques on dentin tubule penetration of nanoparticle calcium hydroxide (NCH) dressing. Ninety-six extracted upper incisors were shaped up to #40file. Then, Four experimental groups were formed according to the final irrigation procedure: conventional needle irrigation (CNI), manual dynamic agitation (MDA), sonic agitation (SA) and ultrasonic irrigant agitation (UIA). According to the intracanal drug used, these groups were divided into two subgroups: calcium hydroxide (CH) and NCH. Prepared CH preparations were labelled with Rhodamine B, and CH or NCH were placed in root canals. In the UIA group, both CH and NCH had the highest penetration depth and percentage compared to the other groups (p < 0.05). The penetration depth and percentage of NCH in the UIA and SA groups were significantly higher than in the CH groups (p < 0.05). UIA is more effective than other groups in increasing dentinal tubule penetration of CH and NCH.

Comparison of the Penetration Depth of 905 nm and 1064 nm Laser Light in Surface Layers of Biological Tissue Ex Vivo.

The choice of parameters for laser beams used in the treatment of musculoskeletal diseases is of great importance. First, to reach high penetration depths into biological tissue and, secondly, to achieve the required effects on a molecular level. The penetration depth depends on the wavelength since there are multiple light-absorbing and scattering molecules in tissue with different absorption spectra. The present study is the first comparing the penetration depth of 1064 nm laser light with light of a smaller wavelength (905 nm) using high-fidelity laser measurement technology. Penetration depths in two types of tissue ex vivo (porcine skin and bovine muscle) were investigated. The transmittance of 1064 nm light through both tissue types was consistently higher than of 905 nm light. The largest differences (up to 5.9%) were seen in the upper 10 mm of tissue, while the difference vanished with increasing tissue thickness. Overall, the differences in penetration depth were comparably small. These results may be of relevance in the selection of a certain wavelength in the treatment of musculoskeletal diseases with laser therapy.

Fractionated Sonodynamic Therapy Using Gold@Poly(ortho-aminophenol) Nanoparticles and Multistep Low-Intensity Ultrasound Irradiation to Treat Melanoma Cancer: In Vitro and In Vivo Studies.

Cancer treatment using ultrasound irradiation with low intensities along with a sonosensitizer has been found to have significant advantages, such as high penetration depth in tissues, non-invasive therapeutic character, minor side effects, good patient adherence and preferential tumor area treatment. In the present study, gold nanoparticles covered by poly(ortho-aminophenol) (Au@POAP NPs) were synthesized and characterized as a new sonosensitizer. We investigated Au@POAP NPs efficacy on fractionated ultrasound irradiation for treatment of melanoma cancer in vitro as well as in vivo. In vitro examinations revealed that although Au@POAP NPs (with a mean size of 9.8 nm) alone represented concentration-dependent cytotoxicity against the B16/F10 cell line, multistep ultrasound irradiation (1 MHz frequency, 1.0 W/cm2 intensity, 60 s irradiation time) of the cells in the attendance of Au@POAP NPs led to efficient cell sonodynamic therapy (SDT) and death. Histological analyses revealed that in vivo fractionated SDT toward melanoma tumors of male balb/c mice led to no residual viable tumor cell after 10 d. A deep sonosensitizing effectiveness of Au@POAP NPs on fractionated low-intensity ultrasound irradiation was attained with the main mechanism of tumor cell eradication of promotion of apoptosis or necrosis through dramatically increased reactive oxygen species levels.

ClO– Induced Dual-Excitation Fluorescent Probes Responding to Diverse Testing Modes with Ratio Methodology

Single-excitation ratio fluorescent probes have enabled the output signal with high signal-to-noise ratio, but are still plagued with technique challenges, including signal distortion and limited application scenario. Herein, a dual-excitation near-infrared (NIR) fluorescent probe P1 of coumarin derivatives is constructed, showing high signal output ability in the visible region and high tissue penetration depth ability in the NIR region. As NIR probe P1 selectively recognizes ClO-, the emission signal in the visible region (480 nm) of P1 is enhanced during the recognition process. Meanwhile, the NIR emission (830 nm) of the conjugated system is weakened, finally realizing that ClO- triggered the dual-excitation (720/400 nm) ratio fluorescence signal detection and monitoring. The signal of detection in vitro has high responsiveness. Meanwhile, in the process of NIR monitoring in vivo, positive contrast imaging of fluorescence is constructed, which can accurately monitor ClO- changes over time. The current dual-excitation fluorescence-based data calibration and/or comparison method improves the application of the traditional single-excitation ratio fluorescence strategy and provide innovative detection tools for accurate measurement of fluorescence detection, with detection/monitoring modes suitable for different physiological environments.

Sonodynamic Bacterial Inactivation Enhanced by an Actuator‐Integrated Mechanism

AbstractSonodynamic bacterial inactivation, a reactive oxygen species (ROS)‐empowered approach featuring high penetration depth and low health risk, is explored for antibiotic‐free antibacterial treatment. However, the low yield and insufficient diffusion of ROS negatively affect the antibacterial efficacy of sonodynamic treatment, thus hindering its further development. Here an actuator‐integrated mechanism is proposed for enhancing the sonodynamic efficacy of loaded sonosensitizers through motion‐induced hydrodynamic effects, demonstrated by a porphyrin‐decorated gold nanomotor, which can produce ROS for bacterial inactivation while performing multimodal motion via actuation using low‐frequency ultrasound. Corroborated by numerical simulation, the experimental results show that the motor's stirring motion significantly increases the yield and diffusion of ROS through fluid flow and frequent interactions between the motor and bacterial targets, resulting in doubled antibacterial efficiency in comparison to a stationary motor. Furthermore, the flow‐induced shear forces combined with the frequent interactions constitute a source of mechanical damage and can form a synergy with the antibacterial properties of ROS, enabling an efficient biofilm eradication that is inaccessible by freely suspended porphyrin. In conclusion, this study reports a motion‐based strategy to enhance sonodynamic efficacy and provides proof of concept using a sonodynamic gold nanomotor powered by ultrasound.

Radar-based measurements of the solids flow in a circulating fluidized bed

The aim of this work is to demonstrate the value of radar technology for studying experimentally the solids flows in gas-solids fluidized beds. The work presents original results regarding the solids concentration and velocity acquired in a non-intrusive manner from a cold flow model. The tailored radar setup operates at submillimeter wave frequencies (0.34THz) and can measure the location of solids with a spatial resolution of 1/8 mm−1 in the direction of the radar beam, and of 40–60 mm across the radar beam. The solids velocity in the direction of the beam propagation is determined through measurement of the Doppler shift caused by the reflection of the transmitted radar signal by solids moving in relation to the antenna. The measurements were performed in both the horizontal and vertical directions in the riser of a circulating fluidized bed (cross-sectional area of 0.45 m2 and height of 3.1 m) operated with glass beads (mean particle size of 106 µm, and particle density of 2,486 kg/m3) and using air at ambient temperature as the fluidization agent, with superficial velocities in the range of 0.3–1.3 m/s. The measurements are used to assess the validity of the technique and are not intended to characterize the unit fluid dynamically. The solids concentrations derived from the radar measurements follow the qualitative trends derived from pressure-drop measurements, resembling the expected changes that occur in the concentration profiles as the fluidization velocity increases. Concentrations in the range from 10-6 m3/m3 to 10-1 m3/m3 are measurable. In quantitative terms, for low concentrations of solids (<5·10-3 m3/m3, approximately) the radar measurements exhibited the ability to provide more consistent measurements of the solids concentration than those obtained from pressure transducers, for which the small pressure differences lead to unstable and even negative values for solids concentrations. The two measurement methods were in quantitative agreement for solids volume fractions higher than the threshold. Concentrations ≥ 1·10-1 m3/m3, though measurable, strongly attenuate the radar signal, thereby reducing the beam penetration to a depth of centimeters. For each position along the radar beam, the distribution of solids velocity measured from the Doppler effect was found to be within the expected ranges and allowed observations of solids back-mixing. The radar technique applied in this work is a promising technique for detailed characterization of the solids flow influidized beds, offering high spatial and temporal resolutions, allowing the determination of both solids velocity and concentration, and having a reasonably high penetration depth.

Radionuclide labeled nanocarrier for imaging guided combined radionuclide, sonodynamic, and photothermal therapy of pancreatic tumours

Radionuclide therapy (RNT) is an effective method for the clinical precise treatment of cancer. However, the uneven dose distribution and rapid metabolism of nuclides limit the effective killing of tumors. To overcome the limitations of radionuclide therapeutic approaches, combining different therapeutic strategies to treat cancer has manifested great promise in basic and clinical research. Here, a new combination therapy strategy was developed to combine radionuclide therapy, sonodynamic therapy and photothermal therapy (RNT-SDT-PTT) under radionuclide imaging guided achieve highly effective combination therapy. We prepared a polydopamine-modified Au nanostar (AN), then loaded with the acoustic sensitizer protoporphyrin (IX) and labeled with diagnostic (99mTc) or therapeutic (131I) radionuclides (131I/99mTc-AN@D/IX) for the precise diagnosis and treatment of pancreatic cancer. After intratumor administration, single photon emission computed tomography imaging showed that the nanocarriers were mostly retained in the tumor compared to free radionuclide. As well as using near-infrared light to trigger PTT and ultrasound with high penetration depth to activate IX to generate reactive oxygen species achieved SDT of tumor. The ultimate significantly improved the inhibitory effects by the RNT-SDT-PTT combined therapy for pancreatic cancer. Therefore, this study proposes an effective radionuclide combination therapy regimen consisting of three widely used treatments, offering promising prospects for the future of oncology.