Magnetic resonance imaging (MRI) is a non-invasive imaging technology to diagnose health conditions, showing the weakness of low sensitivity. Herein, we synthesize a contrast agent, SPIO@SiO₂@MnO₂, which shows decreased T₁ and T₂ contrast intensity in normal physiological conditions. In the acid environment of tumor or inflamed tissue, the manganese dioxide (MnO₂) layer decomposes into magnetically active Mn²⁺ (T₁-weighted), and the T₁ and T₂ signals are sequentially recovered. In addition, both constrast quenching-activation degrees of T₁ and T₂ images can be accurately regulated by the silicon dioxide (SiO₂) intermediate layer between superparamagnetic iron oxide (SPIO) and MnO₂. Through the “dual-contrast enhanced subtraction” imaging processing technique, the contrast sensitivity of this MRI contrast agent is enhanced to a 12.3-time difference between diseased and normal tissue. Consequently, SPIO@SiO₂@MnO₂ is successfully applied to trace the tiny liver metastases of approximately 0.5 mm and monitor tissue inflammation.

To compare dual energy CT iodine imaging and standardized iodine concentration before and after chemoradiotherapy (CRT) for esophageal cancer and evaluate the efficacy of CRT for EC by examining DECT iodine maps and standard CT values. The clinical data of 45 patients confirmed by pathology with newly diagnosed esophageal cancer who underwent concurrent CRT from February 2012 to January 2017 in our department of radiology were collected. All patients underwent dual-source dual-energy CT (DECT) before and after CRT. Normalized iodine concentration (NIC) and normalized CT (NCT) corresponding to the overall cancer lesion and its maximum cross-sectional area were observed and compared. Additionally, 30 healthy individuals were compared as control group. After treatment, the patients were divided into two groups according to RECIST1.1: treatment effective group and ineffective group. There were 33 patients (CR 9, PR 24) in the effective group and 12 patients (SD 12, PD 0) in the ineffective group. There was no significant difference in the NIC-A, NIC-V, NCT-A and NCT-A indexes between the effective group (B group) and the ineffective group (C group) before treatment (P > 0.05). After the treatment, the above-mentioned indexes in the effective group of patients were significantly lower than before treatment, and compared with the ineffective group, the NIC-A, NIC-V, NCT-A and NCT-V values of the effective group were significantly lower than those of ineffective group (P < 0.05). After treatment, the NIC-V and NCT-V in the ineffective group were lower than before treatment, and the difference was statistically significant (P < 0.05). However, their NIC-A and NCT-A were not statistically different from those before treatment (P > 0.05). Using DECT iodine map, the changes of NIC and NIC before and after CRT in patients with esophageal cancer can evaluate the effect of CRT, and does not increase the radiation dose, so it is suitable for clinical use.

Construction of micro tumor sensitive theranostic nanoagents that can increase the accuracy of imaging diagnosis and boost the therapeutic efficacy has been demonstrated for a promising approach for diagnosis and treatment of cancer. Herein, we reported a novel super-paramagnetic iron oxide (SPIO) based nanoplatform that possess significantly enhanced magnetic resonance property and photothermal effect for tumor theranostic purpose. This polyethylene glycol with four phenylboronic acid (PEG-B4)/CNTs@porphyrin (ph)/SPIO (BCPS) nanoplatform was simply prepared via integrated SPIO, ph, and a novel dendrimer with PEG liner and four PBA groups (PEG-B4) on the surface of carbon nanotubes (CNTs). Subsequently, a significant T2 relaxation rate enhanced can be achieved by the reduced accessibility of water to SPIO clustering. Moreover, the synergetic enhanced photothermal from BCPS nanoplatform contributed to better photothermal effect for cancer therapy. Furthermore, the targeting ability to sialic acid overexpressed tumor was further introduced from phenylboronic acid from PEG-B4. We showed that BCPS nanoplatform could not only selectively identify solid tumors and detect micro-sized metastatic tumor (1 mm) in the liver, but also effectively ablate tumors in a xenograft model, thereby achieving a complete cure rate of 100% at low laser dose. Our results highlight the potential of BCPS nanoplatform for accurate micro-tumor diagnosis and effective tumor therapy.

Nanotheranostics with comprehensive diagnostic and therapeutic capabilities show exciting cancer treatment potentials. Here, we develop an excipient-free drug delivery system for cancer diagnosis as well as therapy, in which a near infra-red photosensitizer and a chemotherapeutic drug can be self-delivered without any carriers. The building block of the drug delivery system was synthesized by covalently conjugating four anticancer drugs (7-ethyl-10-hydroxy-camptothecin, SN-38) with a photosensitizer (porphyrin) via hydrolyzable ester linkage, which endows the drug delivery system with 100% active pharmaceutical ingredients, excellent imaging, and therapeutic functionalities. The conjugates can readily self-assemble into nanosheets (PS NSs) and remain stable for at least 20 days in aqueous solution. In PS NSs, fluorescence resonance energy transfer (FRET) dominates the fluorescence of SN-38 and enables to monitor the drug release fluorescently. The PS NSs also show excellent anticancer activity in vitro, due to the increased cell uptake with the synergistic effect of photodynamic therapy and chemotherapy.

BACKGROUND: It is difficult to distinguish solitary of fibrous tumor/hemangiopericytoma (SFT/HPC) from atypical meningioma (AM) by conventional imaging.As far as we know,diffusion weighting imaging may identify them effectively. OBJECTIVE: The purpos