A Mitochondria-targeted AIEgen Labelled with 18F for Breast Cancer Cell Imaging and Therapy

A lack of efficient diagnostic tools for early and noninvasive diagnosis of breast cancer has restricted the clinical treatment effect. This problem might be addressed by the combination of aggregation-induced emission (AIE) fluorescence imaging and positron emission tomography (PET) with the dual advantages of high resolution and easy operation, and unlimited penetration and high sensitivity. Here, a mitochondria-targeted AIE luminogen (AIEgen) radiolabeled with ¹⁸F was developed through a two-step radiochemical reaction by virtue of a prosthetic group. The obtained ^18/19F-Bz-CP imaging probe was examined by in vitro cell uptake and cell proliferation inhibition in two breast cancer cell lines, showing that the probe can efficiently target and locate in the mitochondria through the analysis of fluorescence imaging and PET simultaneously. Additionally, the probe can induce cancer cell apoptosis with the half maximal inhibitory concentration (IC50) of 4.8 μM for MCF-7 cells and 7.2 μM for T47D cells, indicating its potential application for breast cancer therapy.     

Anti-epidermal growth factor receptor (anti-EGFR) antibody conjugated fluorescent nanoparticles probe for breast cancer imaging

Fluorescent nanoparticles (FNs) with unique optical properties may be useful as biosensors in living cancer cell imaging and cancer targeting. In this study, anti-EGFR antibody conjugated fluorescent nanoparticles (FNs) (anti-EGFR antibody conjugated FNs) probe was used to detect breast cancer cells. FNs with excellent character such as non-toxicity and photostability were first synthesized with a simple, cost-effective and environmentally friendly modified Stőber synthesis method, and then successfully modified with anti-EGFR antibody. This kind of fluorescence probe based on the anti-EGFR antibody conjugated FNs has been used to detect breast cancer cells with fluorescence microscopy imaging technology. The experimental results demonstrate that the anti-EGFR antibody conjugated FNs can effectively recognize breast cancer cells and exhibited good sensitivity and exceptional photostability, which would provide a novel way for the diagnosis and curative effect observation of breast cancer cells and offer a new method in detecting EGFR.     

Bioorthogonal oxime ligation mediated in vivo cancer targeting

Current cancer targeting relying on specific biological interaction between the cell surface antigen and respective antibody or its analogue has proven to be effective in the treatment of different cancers; however, this strategy has its own limitations, such as the heterogeneity of cancer cells and immunogenicity of the biomacromolecule binding ligands. Bioorthogonal chemical conjugation has emerged as an attractive alternative to biological interaction for in vivo cancer targeting. Here, we report an in vivo cancer targeting strategy mediated by bioorthogonal oxime ligation. An oxyamine group, the artificial target, is introduced onto 4T1 murine breast cancer cells through liposome delivery and fusion. Poly(ethylene glycol)-polylactide (PEG-PLA) nanoparticles (NPs) are surface-functionalized with aldehyde groups as targeting ligands. The improved in vivo cancer targeting of PEG-PLA NPs is achieved through specific and efficient chemical reaction between the oxyamine and aldehyde groups.     

Dual-Targeting Biomimetic Semiconducting Polymer Nanocomposites for Amplified Theranostics of Bone Metastasis

Bone metastasis is a type of metastatic tumors that involves the spreads of malignant tumor cells into skeleton, and its diagnosis and treatment remain a big challenge due to the unique tumor microenvironment. We herein develop osteoclast and tumor cell dual-targeting biomimetic semiconducting polymer nanocomposites (SPFeN_OC) for amplified theranostics of bone metastasis. SPFeN_OC contain semiconducting polymer and iron oxide (Fe₃O₄) nanoparticles inside core and surface camouflaged hybrid membrane of cancer cells and osteoclasts. The hybrid membrane camouflage enables their targeting to both metastatic tumor cells and osteoclasts in bone metastasis through homologous targeting mechanism, thus achieving an enhanced nanoparticle accumulation in tumors. The semiconducting polymer mediates near-infrared (NIR) fluorescence imaging and sonodynamic therapy (SDT), and Fe₃O₄ nanoparticles are used for magnetic resonance (MR) imaging and chemodynamic therapy (CDT). Because both cancer cells and osteoclasts are killed synchronously via the combinational action of SDT and CDT, the vicious cycle in bone metastasis is broken to realize high antitumor efficacy. Therefore, 4T1 breast cancer-based bone metastasis can be effectively detected and cured by using SPFeN_OC as dual-targeting theranostic nanoagents. This study provides an unusual biomimetic nanoplatform that simultaneously targets osteoclasts and cancer cells for amplified theranostics of bone metastasis.     

Monodisperse Magnetite Nanoparticles Coupled with Nuclear Localization Signal Peptide for Cell‐Nucleus Targeting

Functionalization of monodisperse superparamagnetic magnetite (Fe₃O₄) nanoparticles for cell specific targeting is crucial for cancer diagnostics and therapeutics. Targeted magnetic nanoparticles can be used to enhance the tissue contrast in magnetic resonance imaging (MRI), to improve the efficiency in anticancer drug delivery, and to eliminate tumor cells by magnetic fluid hyperthermia. Herein we report the nucleus‐targeting Fe₃O₄ nanoparticles functionalized with protein and nuclear localization signal (NLS) peptide. These NLS‐coated nanoparticles were introduced into the HeLa cell cytoplasm and nucleus, where the particles were monodispersed and non‐aggregated. The success of labeling was examined and identified by fluorescence microscopy and MRI. The work demonstrates that monodisperse magnetic nanoparticles can be readily functionalized and stabilized for potential diagnostic and therapeutic applications.     

Targeting cancer cells through Mn(II)-dpa grafted silica nanoparticles

The unique properties of paramagnetic nanoscale metal-organic frameworks provide them with high potential as key probes and vectors in the next generation of biomedical applications. To increase the nanoparticle targeting at the tumor site, the grafting of Mn(II)-dpa (dpa =di(picolyl)amines) on oxide nanoparticles (SiO₂) is proposed. The new Mn(II)-dpa-grafted silica nanoparticles can enhance the MR imaging area in cancer tissues and perturb the Ca²⁺-loaded mitochondria swelling. Experimental results indicate the cancer cells may be targeted through possible intracellular Ca²⁺ signaling mitochondria accumulating in vivo.     

Multifunctional nanoprobe for cancer cell targeting and simultaneous fluorescence/magnetic resonance imaging

Multifunctional nanoprobes with distinctive magnetic and fluorescent properties are highly useful in accurate and early cancer diagnosis. In this study, nanoparticles of Fe₃O₄ core with fluorescent SiO₂ shell (MFS) are synthesized by a facile improved Stöber method. These nanoparticles owning a significant core-shell structure exhibit good dispersion, stable fluorescence, low cytotoxicity and excellent biocompatibility. TLS11a aptamer (Apt1), a specific membrane protein for human liver cancer cells which could be internalized into cells, is conjugated to the MFS nanoparticles through the formation of amide bond working as a target-specific moiety. The attached TLS11a aptamers on nanoparticles are very stable and can't be hydrolyzed by DNA hydrolytic enzyme in vivo. Both fluorescence and magnetic resonance imaging show significant uptake of aptamer conjugated nanoprobe by HepG2 cells compared to 4T1, SGC-7901 and MCF-7 cells. In addition, with the increasing concentration of the nanoprobe, T₂-weighted MRI images of the as-treated HepG2 cells are significantly negatively enhanced, indicating that a high magnetic field gradient is generated by MFS-Apt1 which has been specifically captured by HepG2 cells. The relaxivity of nanoprobe is calculated to be 11.5 mg⁻¹s⁻¹. The MR imaging of tumor-bearing nude mouse is also confirmed. The proposed multifunctional nanoprobe with the size of sub-100 nm has the potential to provide real-time imaging in early liver cancer cell diagnosis.     

One‐Step Synthesis of Small‐Sized and Water‐Soluble NaREF4 Upconversion Nanoparticles for In Vitro Cell Imaging and Drug Delivery

Small (2–28 nm) NaREF₄ (rare earth (RE)=Nd–Lu, Y) nanoparticles (NPs) were prepared by an oil/water two‐phase approach. Meanwhile, hydrophilic NPs can be obtained through a successful phase‐transition process by introducing the amphiphilic surfactant sodium dodecylsulfate (SDS) into the same reaction system. Hollow‐structured NaREF₄ (RE=Y, Yb, Lu) NPs can be fabricated in situ by electron‐beam lithography on solid NPs. The MTT assay indicates that these hydrophilic NPs with hollow structures exhibit good biocompatibility. The as‐prepared hollow‐structured NPs can be used as anti‐cancer drug carriers for drug storage/release investigations. Doxorubicin hydrochloride (DOX) was taken as model drug. The release of DOX from hollow α‐NaLuF₄:20 % Yb³⁺, 2 % Er³⁺ exhibits a pH‐sensitive release patterns. Confocal microscopy observations indicate that the NPs can be taken up by HeLa cells and show obvious anti‐cancer efficacy. Furthermore, α‐NaLuF₄:20 % Yb³⁺, 2 % Er³⁺ NPs show bright‐red emission under IR excitation, making both the excitation and emission light fall within the “optical window” of biological tissues. The application of α‐NaLuF₄:20 % Yb³⁺, 2 % Er³⁺ in the luminescence imaging of cells was also investigated, which shows a bright‐red emission without background noise.     

Exploring the anticancer effects of tin oxide nanoparticles synthesized by pulsed laser ablation technique against breast cancer cell line through downregulation of PI3K/AKT/mTOR signaling pathway

Tin oxide nanoparticles (SnO₂ NPs) demonstrate potential anti-cancer functions. However, the anti-cancer mechanisms of SnO₂ NPs have not been explored in detail. In the present study, we synthesized SnO₂ NPs through laser ablation technique and examined their anticancer mechanisms and the probable involvement of the PI3K/AKT mediated pathways in human breast cancer cells (MCF-7) in vitro. The synthesized SnO₂ NPs were characterized by transmission electron microcopy (TEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR) techniques. Afterwards, the breast cancer cells were incubated with increasing concentrations of SnO₂ NPs, and inhibition of cell proliferation was assessed by the viability assay. Furthermore, the quantification of reactive oxygen species (ROS) and apoptosis were examined by flow cytometry followed by superoxide dismutase (SOD) and catalase (CAT) activity as well as mitochondrial membrane potential assays. The expression levels of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), mechanistic target of rapamycin (mTOR), B-cell lymphoma 2 (Bcl-2), and Bax were also assessed by western blot and quantitative real time PCR (qRT-PCR). It was shown that SnO₂ NPs, 30 nm, with potential colloidal stability selectively prevented the proliferation of MCF-7 in comparison with MCF-10A cells and triggered ROS production, apoptosis, deactivation of SOD and CAT activity, and mitigation of mitochondrial membrane potential. Moreover, SnO₂ NPs stimulated mitochondrial-mediated apoptosis pathway by overexpression of Bax/Bcl-2 and downregulation of p-PI3K/p-AKT/p-mTOR signaling pathway. This data elucidates the possible mechanisms by which SnO₂ NPs may stimulate their anticancer effects.     

Purely organic light-harvesting phosphorescence energy transfer by β-cyclodextrin pseudorotaxane for mitochondria targeted imaging

A new type of purely organic light-harvesting phosphorescence energy transfer (PET) supramolecular assembly is constructed from 4-(4-bromophenyl)-pyridine modified β-cyclodextrin (CD-PY) as a donor, cucurbit[8]uril (CB[8]) as a mediator, rhodamine B (RhB) as an acceptor, and adamantane modified hyaluronic acid (HA-ADA) as a cancer cell targeting agent. Interestingly, the complexation of free CD-PY, which has no RTP emission in aqueous solution, with CB[8] results in the formation of CD-PY@CB[8] pseudorotaxane with an RTP emission at 510 nm. Then the addition of RhB leads to an efficient light-harvesting PET process with highly efficient energy transfer and an ultrahigh antenna effect (36.42) between CD-PY@CB[8] pseudorotaxane and RhB. Importantly, CD-PY@CB[8]@RhB assembles with HA-ADA into nanoparticles with further enhanced delayed emission at 590 nm. The nanoparticles could be successfully used for mitochondria targeted imaging in A549 cancer cells. This aqueous-state PET based on a supramolecular assembly strategy has potential application in delayed fluorescence cell imaging.

A new type of purely organic light-harvesting PET supramolecular assembly is constructed with efficient energy transfer and ultrahigh antenna effect. Moreover, the assembly could be used for mitochondria targeted imaging in A549 cancer cells.     

Investigation of anti-human ovarian cancer effects of decorated Au nanoparticles on Thymbra spicata extract modified Fe3O4 nanoparticles

This work describes an eco-friendly approach for in situ immobilization of Au nanoparticles on the surface of Fe₃O₄ nanoparticles, with the help of Thymbra spicata extract and ultrasound irradiations, without using any toxic reducing and capping agents. The combination of Fe₃O₄ NPs and Au NPs in one hybrid nanostructure (Fe₃O₄@Thymbra spicata/Au NPs) represents a promising strategy for targeted biomedical applications. The structure, morphology, and physicochemical properties were characterized by various analytical techniques such as fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), inductively coupled plasma (ICP) and vibrating sample magnetometer (VSM). MTT assay was used on common ovarian cancer cell lines i.e., SW-626, PA-1, and SK-OV-3 to survey the cytotoxicity and anti-ovarian cancer effects of Fe₃O₄@Thymbra spicata/Au NPs. The best results of cytotoxicity and anti-ovarian cancer properties were seen in the concentration of 1000 µg/mL. Fe₃O₄@ Thymbra spicata/Au NPs had very low cell viability and high anti-ovarian cancer activities dose-dependently against PA-1, SW-626, and SK-OV-3 cell lines without any cytotoxicity on the normal cell line (HUVEC). For investigating the antioxidant properties of Fe₃O₄@ Thymbra spicata/Au NPs, the DPPH test was used in the presence of butylated hydroxytoluene as the positive control. Fe₃O₄@Thymbra spicata/Au NPs inhibited half of the DPPH molecules in the concentration of 107 µg/mL. Maybe significant anti-human ovarian cancer potentials of Fe₃O₄@Thymbra spicata/Au NPs against common human ovarian cancer cell lines are linked to their antioxidant activities. After confirming the above results in the clinical trial researches, this formulation can be administrated for the treatment of several types of human ovarian cancers in humans.     

Polyfluorene Nanoparticles Coated with Folate‐Functionalized Triblock Copolymer: Effective Agents for Targeted Cell Imaging

An ultra‐bright fluorescence probe comprising conjugated polymer nanoparticles is developed for biological imaging. Highly blue fluorescent polyfluorene nanoparticles (PF‐NPs) stabilized by sodium dodecylsulfate with an average diameter of 100 nm are prepared by a miniemulsion technique. A folate‐conjugated cationic triblock copolymer is employed to coat negatively charged PF‐NPs via electrostatic interaction for specific cell imaging of folate receptor over‐expressing cancer cells. The coated PF‐NPs show a similar size and morphology to the pristine PF‐NPs, while the fluorescence intensity is enhanced. Such surface‐functionalized PF‐NPs are demonstrated to be suitable probes for efficient cell imaging of folate receptor over‐expressing KB cells by CLSM and flow cytometry.

     

Dual-targeted nanoformulation with Janus structure for synergistic enhancement of sonodynamic therapy and chemotherapy

The accurate delivery of nanoparticles and organic small molecule drugs remains a serious challenge in nanoparticle-based tumor therapy. Dual-targeted therapy combining tumor cell targeting and organelle targeting is an effective solution. Here, an anticancer nanoformulation accurate delivery system was prepared using hyaluronic acid (HA) targeting CD44 receptors on the surface of tumor cells and IR780 iodine (IR780) targeting mitochondrial for delivery. The system is based on an ultra-small Janus structured inorganic sensitizer TiO_2-x@NaGdF₄ nanoparticles (TN NPs) prepared by one-step pyrolysis, further loaded with organic small molecule acoustic sensitizer IR780 and mitochondrial hexokinase II inhibitor lonidamine (LND), followed by encapsulation of HA. Ultra-small size nanoparticles exhibit strong tissue penetration, tumor inhibition and in vivo metabolism. Under ultrasound radiation, TN NPs and IR780 could produce a synergistic effect, effectively increased the efficiency of reactive oxygen species (ROS) production. Meanwhile, the released IR780 could smoothly target the mitochondria, and the ROS produced by IR780 can destroy the mitochondrial structure and disrupt the mitochondrial respiration. LND could inhibit the energy metabolism of tumor cells by reducing the activity of hexokinase II (HK II), which further accelerates the process of apoptosis. Furthermore, since the Janus structure allows the integration of multifunctional components into a single system, TN NPs can not only serve as an acoustic sensitizer to generate ROS, but the Gd element contained can also act as the nuclear magnetic resonance (MR) imaging contrast agent, suggesting that the nanoformulation can enable imaging-guided diagnosis and therapy. In conclusion, a new scheme to enhance sonodynamic therapy (SDT) and chemotherapy synergistically is proposed here based on ultra-small dual-targeted nanoformulation with Janus structure in the ultrasound radiation environment.     

Surface functionalization of two-photon dye-doped mesoporous silica nanoparticles with folic acid: cytotoxicity studies with HeLa and MCF-7 cancer cells

Two-photon dye-doped mesoporous silica nanoparticles (NPs) have been conjugated with folic acid (FA) in order to obtain efficient nanotools for bioimaging of cancer cells. The surface of the NPs was first functionalized with 3-aminopropyltriethoxysilane. The amine-covered NPs were subsequently reacted with an activated ester derivative of FA. Cytotoxicity studies performed with MCF7 and HeLa cancer cells demonstrate that these functionalized NPs are much less cytotoxic than the non-functionalized NPs against both cell lines. Unfortunately, the grafting of FA enables the formation of charge transfer complexes between the two-photon dye and FA which leads to quenching of the fluorescence of the NPs. Hence although these NPs cannot be used for biomaging purposes, they offer interesting potentialities if the two-photon dye used can be replaced by a two-photon fluorophore which do not interact with FA or if the interaction between the encapsulated dye and FA can be prevented by using a suitable spacer between the surface and the FA moiety.     

All-in-one phototheranostics based on BTP-4F-DMO nanoparticles for NIR-II fluorescence/photoacoustic dual-mode imaging and combinational therapy

Various phototheranostics have recently been developed for phototherapy. Through proper molecular design, the photochemical and photophysical properties of these phototheranostics can be promoted. Herein, an acceptor-donor-acceptor (A-D-A)-structured dye, BTP-4F-DMO, was synthesized and prepared into water-soluble nanoparticles (NPs). The obtained BTP-4F-DMO NPs had strong absorption from 650 nm to 850 nm and a fluorescence emission peak at ∼900 nm that tailed to ∼1100 nm. The NPs showed a superhigh photothermal conversion efficiency of 90.5% ± 5% and could simultaneously generate ^•OH and ¹O₂ with a ¹O₂ generation quantum yield of 4.6% under 808 nm laser irradiation. Due to these advanced properties, BTP-4F-DMO NPs can switch the role of autophagy from pro-survival to pro-death, thereby further promoting cancer cell death. These features make BTP-4F-DMO NPs a promising multifunctional phototheranostic agent for NIR-II fluorescence/photoacoustic dual-mode imaging-guided synergetic photodynamic/photothermal therapy. In general, this work provides a strategy for expanding the biomedical applications of organic A-D-A-structured phototheranostics.     

4T1 cell membrane-derived biodegradable nanosystem for comprehensive interruption of cancer cell metabolism

Glycolysis inhibition can effectively block the energy supply and interrupt tumorigenesis in many types of cancers. However, when glycolysis is inhibited, tumor cells will break down glutamine as the raw material for the replenishment pathway to maintain the tricarboxylic acid cycle ensuring energy supply, therefore inducing ineffective interruption of metabolic. Herein, we designed glutamine transporter antagonist L-γ-glutamyl-p-nitroanilide(GPNA) loaded and 4T1 cancer cell membrane coated irid...     

18FDG conjugated magnetic nanoparticle probes: synthesis and in vitro investigations on MCF-7 breast cancer cells

¹⁸FDG conjugated magnetic iron oxide nanoparticles (MNPs) were synthesized as PET-MR hybrid imaging agent. Synthesized and characterized NPs were then applied to MCF-7 human breast cancer cells. ¹⁸FDG conjugated MNPs exhibited the cell incorporation ratio up to 30 %. As well as the characterization studies, apoptotic effects were observed depending on the cellular incorporations by the time. In conclusion, synthesized structures could have a potential as hybrid imaging agent in PET-MR imaging systems besides apoptotic effect on cancer cells.     

89Zr Labeled Fe3O4@TiO2 Nanoparticles: In Vitro Afffinities with Breast and Prostate Cancer Cells

In this study, Fe₃O₄@TiO₂ nanoparticles were synthesized as a new Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) hybrid imaging agent and radiolabeled with ⁸⁹Zr. In addition, Fe₃O₄ nanoparticles were synthesized and radiolabeled with ⁸⁹Zr. Df-Bz-NCS was used as bifunctional ligand. The nanoconjugates were characterized with transmission electron microscopy, scanning electron microscopy, and dynamic light scattering. Radiolabeling yields were 100%. Breast and prostate cancer cell affinities and cytotoxicity were determined using in vitro cell culture assays. The results demonstrated that Fe₃O₄@TiO₂ nanoparticles are promising for PET/MR imaging. Finally, unlike Fe₃O₄ nanoparticles, Fe₃O₄@TiO₂ nanoparticles showed a fluorescence spectrum at an excitation wavelength of 250 nm and an emission wavelength of 314 nm. Therefore, in addition to bearing the magnetic properties of Fe₃O₄ nanoparticles, Fe₃O₄@TiO₂ nanoparticles display fluorescence emission. This provides them with photodynamic therapy potential. Therefore multimodal treatment was performed with the combination of PDT and RT by using human prostate cancer cell line (PC3). The development of ⁸⁹Zr-Df-Bz-NCS-Fe₃O₄@TiO₂ nanoparticles as a new multifunctional PET/MRI agent with photodynamic therapy and hyperthermia therapeutic ability would be very useful.     

Nanomagnetic hydrogel based on chitosan,hyaluronic acid,and glucose oxidase as a nanotheranostic platform for simultaneous therapeutic and imaging applications

Theranostic platform including therapeutic agent and diagnostics factor is of great interest in the current cancer treatment research. In this study, we constructed a pH-responsive nanomagnetic hydrogel based on chitosan, hyaluronic acid, and glucose oxidase (NMH-CsHA-GOx) as a platform, which represents good performance both as a nanomedicine and as a dual-modal magnetic resonance imaging (MRI) contrast agent. The NMH-CsHA-GOx is a hybrid catalyst that catalyzes a cascade reaction that results in the production of hydroxyl radicals. This leads to the apoptosis and death of cancer cells under the mildly acidic TME. Moreover, the ultrasmall superparamagnetic Fe₃O₄ NPs act as the T₁-weighted and T₂-weighted (dual-modal) MRI contrast agents that can be used to identify the cancer cells. The r₁ = 6.37, r₂ = 27.07/mM/s, and r₂/r₁ ratio were obtained from MRI relaxivity measurements. The NMH-CsHA-GOx was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). The morphology of the hydrogel and nanomagnetic hydrogel were characterized by Field emission scanning electron microscopy (FESEM). The size and distribution of Fe₃O₄NPs were studied by Transmission electron microscopy (TEM) and X-ray elemental mapping, respectively. The analysis confirmed the very small size of the Fe₃O₄ NPs (5–12 nm), which were dispersed uniformly. The NMH-CsHA-GOx represents high selectivity between normal cells (L929 mouse fibroblast cell line) and tumor cells (MCF-7 breast cancer cell line). The pH-sensitive NMH-CsHA-GOx, can produce a controlled amount of hydroxyl radical under the mildly acidic TME.     

Self-carried AIE nanoparticles for in vitro non-invasive long-term imaging

In this study, we report the synthesis of highly emissive AIEgen-based NPs as long-term cell trackers, which enjoy the advantages of high brightness, good stability, large Stokes shift, good biocompatibility, and high photostability. The SCA NPs were successfully applied for in vitro long-term bio-imaging of HeLa cells, indicating that the SCA NPs could be ideal fluorescent probes for non-invasive long-term cellular imaging.