A porphyrin-based magnetic and fluorescent dual-modal nanoprobe for tumor imaging

Gadolinium Functionalized Carbon Dot Complexes for Dual-Modal Imaging: Structure, Performance, and Applications

Gadolinium functionalized carbon dot complexes (Gd-CDs) have both the fluorescent properties of carbon dots and the magnetic characteristics of gadolinium ions, exhibiting excellent biocompatibility, high spatial resolution, high sensitivity, and deep tissue penetration in bioimaging. As fluorescence (FL) and magnetic resonance imaging (MRI) probes, Gd-CDs have attracted significant attention in dual-modal biological imaging. This review summarizes recent advances in Gd-CDs, focusing on their structure, optical and magnetic properties, and applications in dual-modal imaging. First, according to the different existing forms of gadolinium in carbon dots, the structures of Gd-CDs are categorized into chelation, electrostatic interaction, and encapsulation. Second, the mechanisms and performances of Gd-CDs in dual-modal imaging are introduced in detail. The reported Gd-CDs have a maximum quantum yield of 69.86%, with a fluorescence emission wavelength reaching up to 625 nm, and the optimum longitudinal and transverse relaxivity rates are 35.39 and 115.6 mM-1 s-1, respectively, showing excellent FL/MRI capacities. Subsequently, the progress in their applications in dual-modal cellular imaging, in vivo imaging, and integrated cancer diagnosis and therapy is reviewed. Finally, the challenges and issues faced by Gd-CDs in their development are summarized, providing new insights for their controlled synthesis and widespread application in the biomedical field of dual-modal imaging.

Recognition of MCF-7 breast cancer cells using native collagen probes: Collagen source effect

Developing superior cancer cell recognition probes is crucial for the development of tumor therapy and cancer early screening materials. In this study, we first achieved effective recognition of MCF-7 breast cancer cells using natural collagen probes. Through cell adhesion, cancer cell selective capture, and flow cytometry techniques, the binding efficiency of mammalian-derived collagens (bovine Achilles tendon collagen, porcine skin collagen) and fish-derived collagens (turbot skin collagen, grass carp skin collagen, mandarin fish skin collagen) to cancer cells (MCF-7 breast cancer cells) and normal cells (human umbilical vein endothelial cells, HUVECs) was analyzed and compared. The feasibility of different source collagens as probes for recognition of MCF-7 cells was explored in vitro. The results indicated that mammalian-derived collagens had a superior advantage over fish-derived collagens in recognizing MCF-7 cells, with bovine Achilles tendon collagen achieving a capture rate of up to 64.7 % in a multicellular co-culture system. Furthermore, in vivo imaging of BALB/c tumor-bearing mice confirmed the high-efficiency targeted recognition performance of the bovine Achilles tendon collagen probe for MCF-7 cells.

New insight into the application of fluorescence platforms in tumor diagnosis: From chemical basis to clinical application

Early and rapid diagnosis of tumors is essential for clinical treatment or management. In contrast to conventional means, bioimaging has the potential to accurately locate and diagnose tumors at an early stage. Fluorescent probe has been developed as an ideal tool to visualize tumor sites and to detect biological molecules which provides a requirement for noninvasive, real-time, precise, and specific visualization of structures and complex biochemical processes in vivo. Rencently, the development of synthetic organic chemistry and new materials have facilitated the development of near-infrared small molecular sensing platforms and nanoimaging platforms. This provides a competitive tool for various fields of bioimaging such as biological structure and function imaging, disease diagnosis, in situ at the in vivo level, and real-time dynamic imaging. This review systematically focused on the recent progress of small molecular near-infrared fluorescent probes and nano-fluorescent probes as new biomedical imaging tools in the past 3-5 years, and it covers the application of tumor biomarker sensing, tumor microenvironment imaging, and tumor vascular imaging, intraoperative guidance and as an integrated platform for diagnosis, aiming to provide guidance for researchers to design and develop future biomedical diagnostic tools.

Synthesis of a Thermal-Responsive Dual-Modal Supramolecular Probe for Magnetic Resonance Imaging and Fluorescence Imaging

Dual-modal imaging can integrate the advantages of different imaging technologies, which could improve the accuracy and efficiency of clinical diagnosis. Herein, a novel amphiphilic thermal-responsive copolymer obtained from three types of monomers, N-isopropyl acrylamide, 2-(acetoacetoxy) ethyl methacrylate, and propargyl methacrylate, by RAFT copolymerization, is reported. It can be grafted with β-cyclodextrin and aggregation-induced emission (AIE) luminogens tetraphenylethylene by click chemistry and Biginelli reaction. The multifunctional supramolecular polymer (P4) can be constructed by host-guest inclusion between the copolymer and the Gd-based contrast agent (CA) modified by adamantane [Ad-(DOTA-Gd)]. And it can form vesicles with a bilayer structure in aqueous which will enhance the AIE and magnetic resonance imaging effects. As fluorescent thermometer, P4 can enter HeLa cells for intracellular fluorescence imaging (FI) and is sensitive to temperature with detection limit value of 1.5 °C. As magnetic resonance CA, P4 exhibits higher relaxation compared to Magnevist, which can prolong the circulation time in vivo. In addition, Gd³⁺ in the polymer can be quickly released from the body by disassembly that reduced the biological toxicity. This work introduces new synthetic ideas for dual-modal probe, which has great potential for clinical diagnostic applications in bioimaging.

Raman optical identification of renal cell carcinoma via machine learning

High pathologic tumor-node-metastasis (pTNM) stage grade or Fuhrman grade indicates poor oncological outcome in renal cell carcinoma (RCC). Early diagnosis and screening of these RCCs and adjust surgical planning accordingly are greatly beneficial to patients. Raman spectroscopy is a highly specific fingerprint spectrum on molecular level, pretty appropriate for label-free and noninvasive cancer diagnosis. In this work we established a Raman spectrum-based supporting vector machine (SVM) model to accurately ex vivo distinguish human renal tumor from normal tissues and fat with an accuracy of 92.89%. The model can also be used to determine tumor boundary, showing consistent results to pathological staining analysis. This method can be additionally used to accomplish the classification purposes of renal tumor subtypes and grades with an accuracy of 86.79% and 89.53%, respectively. Therefore, we prove that Raman spectroscopy has great potential in the rapid and accurate clinical diagnosis of renal cancers.

Surface charge of well-defined polymeric nano-stars regulates non-invasive fluorescence imaging of lymph node

Accurate identification of sentinel lymph node (SLN) is crucial for clinical SLN biopsy surgery. Herein, we developed an innovative nanoprobe based on well-defined core crosslinked star (CCS) polymers for non-invasive fluorescence imaging of SLN. A well-defined biodegradable CCS polymer comprising multiple polyethylene glycol (PEG) arms and carboxyl terminal groups (denoted as CCS-COOH) was synthesized successfully by reversible addition-fragmentation chain transfer polymerization with a disulfide-based crosslinker reagent. Besides, CCS-COOH was coupled by tert-butyl carbazate to produce the CCS derivative with neutral butoxycarbonyl (Boc) terminal groups (denoted as CCS-Boc). By the removal of Boc groups, another CCS derivative with positive primary amino terminal groups (denoted as CCS-NH₂) was also yielded. These CCS polymers had similar particle size but different surface charge. For SLN fluorescence imaging, the CCS polymers labeled by CY7, a near-infrared probe, exhibited superior in vitro photo-stability to CY7 alone. After intradermal injection of the CY7-labeled CCS polymers in a mouse model, they could efficiently accumulate in the lymph node of the mouse. CY7-labeled CCS-COOH having negatively-charged surface displayed longer duration time and higher fluorescence intensity in the lymph node as compared to its counterparts with neutral or positive charge surface. In vitro and in vivo toxicity tests supported low cytotoxicity of these CCS polymers against cell lines and low systemic toxicity. The results of this work highlight the potential of negatively-charged near-infrared-emitting CCS polymer as a new nanoprobe for safe and efficient SLN imaging.

Recent developments in multimodality fluorescence imaging probes

Multimodality optical imaging probes have emerged as powerful tools that improve detection sensitivity and accuracy, important in disease diagnosis and treatment. In this review, we focus on recent developments of optical fluorescence imaging (OFI) probe integration with other imaging modalities such as X-ray computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and photoacoustic imaging (PAI). The imaging technologies are briefly described in order to introduce the strengths and limitations of each techniques and the need for further multimodality optical imaging probe development. The emphasis of this account is placed on how design strategies are currently implemented to afford physicochemically and biologically compatible multimodality optical fluorescence imaging probes. We also present studies that overcame intrinsic disadvantages of each imaging technique by multimodality approach with improved detection sensitivity and accuracy.

Electrostatic self-assembled nanoparticles based on spherical polyelectrolyte brushes for magnetic resonance imaging

Electrostatic self-assemblies based on SPBs and Gd-DTPA-NO-C₄ exhibit perfect relaxometric performance.

A facile synthesis of a theranostic nanoparticle by oxidation of dopamine-DTPA-Gd conjugates

Photothermal therapies (PPTs) with various light-absorbing materials have shown very promising therapeutic effects against cancers. However, their application was severely limited by the lack of accurate localization of tumors and real-time monitoring of the therapeutic process. Theranostic nanoparticles with both imaging and therapeutic functions are highly desired to develop imaging-mediated PPTs. Herein, we develop a facile one-pot method to synthesize a nanoparticle with functions of an MRI contrast agent and a PTT agent through oxidization of dopamine-DTPA-Gd conjugates and PEG-dopamine conjugates. The oxidized dopamine nanoparticles (ODNP) had a high R1 up to 9.6 mM^-1 s^-1, 2.2 times higher than that of Omniscan, and showed significantly higher MRI contrast enhancement than Omniscan in tumor. Meanwhile, the ODNP showed strong NIR light absorption and significant antitumor efficacy both in vitro and in vivo as a PPT agent. The ODNP with excellent MRI contrasting capability and PTT efficacy plus its facile synthesis and good biocompatibility are a very promising theranostic agent for MRI-mediated PTT.

Enhancing MRI of liver metastases with a zwitterionized biodegradable dendritic contrast agent

The MRI enhanced by a zwitterionized dendritic contrast agent clearly indicates metastatic tumors in the liver.

An ultrasensitive chemiluminescence aptasensor for indirect hemin detection based on aptamer recognition materials

MGO@H-Atp@Co-PP polymers were successfully prepared and used to construct a MGO@H-Atp@Co-PP-CL aptasensor.