Black Phosphorus/MnO2 Nanocomposite Disrupting Bacterial Thermotolerance for Efficient Mild-Temperature Photothermal Therapy.

The emergence of multi-drug resistant (MDR) pathogens is a major public health concern, posing a substantial global economic burden. Photothermal therapy (PTT) at mild temperature presents a promising alternative to traditional antibiotics due to its biological safety and ability to circumvent drug resistance. However, the efficacy of mild PTT is limited by bacterial thermotolerance. Herein, a nanocomposite, BP@Mn-NC, comprising black phosphorus nanosheets and a manganese-based nanozyme (Mn-NZ) is developed, which possesses both photothermal and catalytic properties. Mn-NZ imparts glucose oxidase- and peroxidase-like properties to BP@Mn-NC, generating reactive oxygen species (ROS) that induce lipid peroxidation and malondialdehyde accumulation across the bacterial cell membrane. This process disrupts unprotected respiratory chain complexes exposed on the bacterial cell membrane, leading to a reduction in the intracellular adenosine triphosphate (ATP) content. Consequently, mild PTT mediated by BP@Mn-NC effectively eliminates MDR infections by specifically impairing bacterial thermotolerance because of the dependence of bacterial heat shock proteins (HSPs) on ATP molecules for their proper functioning. This study paves the way for the development of a novel photothermal strategy to eradicate MDR pathogens, which targets bacterial HSPs through ROS-mediated inhibition of bacterial respiratory chain activity.

pH-sensitive gold nanoclusters labeling with radiometallic nuclides for diagnosis and treatment of tumor.

The acidic microenvironment is one of the remarkable features of tumor and is also a reliable target for tumor theranostics. Ultrasmall gold nanoclusters (AuNCs) have good in vivo behaviors, such as non-retention in liver and spleen, renal clearance, and high tumor permeability, and held great potential for developing novel radiopharmaceuticals. Herein, we developed pH-sensitive ultrasmall gold nanoclusters by introducing quaternary ammonium group (TMA) or tertiary amine motifs (C6A) onto glutathione-coated AuNCs (TMA/GSH@AuNCs, C6A-GSH@AuNCs). Density functional theory simulation revealed that radiometal 89Sr, 223Ra, 44Sc, 90Y, 177Lu, 89Zr, 99mTc, 188Re, 106Rh, 64Cu, 68Ga, and 113Sn could stably dope into AuNCs. Both TMA/GSH@AuNCs and C6A-GSH@AuNCs could assemble into large clusters responding to mild acid condition, with C6A-GSH@AuNCs being more effective. To assess their performance for tumor detection and therapy, TMA/GSH@AuNCs and C6A-GSH@AuNCs were labeled with 68Ga, 64Cu, 89Zr and 89Sr, respectively. PET imaging of 4T1 tumor-bearing mice revealed TMA/GSH@AuNCs and C6A-GSH@AuNCs were mainly cleared through kidney, and C6A-GSH@AuNCs accumulated in tumors more efficiently. As a result, 89Sr-labeled C6A-GSH@AuNCs eradicated both the primary tumors and their lung metastases. Therefore, our study suggested that GSH-coated AuNCs held great promise for developing novel radiopharmaceuticals that specifically target the tumor acidic microenvironment for tumor diagnosis and treatments.

Tumor microenvironment-responsive nanohybrid for hypoxia amelioration with photodynamic and near-infrared II photothermal combination therapy.

Phototherapy, particularly photothermal therapy (PTT) and photodynamic therapy (PDT), has been widely investigated for tumor treatment. However, the limited tissue penetration depth of light in the near-infrared I (NIR-I) region and the hypoxic tumor microenvironment (TME) severely constrain their clinical applications. To address these challenges, in the present study, we developed a chlorin e6 (Ce6) and MnO2-coloaded, hyaluronic acid (HA)-coated single-walled carbon nanohorns (SWNHs) nanohybrid (HA-Ce6-MnO2@SWNHs) for PDT and PTT combination therapy of tumor. HA-Ce6-MnO2@SWNHs responded to the mild acidic TME to ameliorate tumor hypoxia, thus enhancing tumor PDT. Moreover, HA-Ce6-MnO2@SWNHs had a high photothermal conversion efficiency at 1064 nm (55.48%), which enabled deep tissue penetration (3.05 cm) and allowed for highly efficient tumor PTT in near-infrared II (NIR-II) window. PDT and PTT combination therapy with HA-Ce6-MnO2@SWNHs achieved a good therapeutic efficacy on 4T1 tumor-bearing mice, eradicating the primary tumors and suppressing cancer recurrence. Our study provides a promising strategy for developing a hypoxia relief and deep tissue penetration phototherapy platform by using SWNHs for highly effective tumor PDT and NIR-II PTT combination therapy. STATEMENT OF SIGNIFICANCE: The hypoxic tumor microenvironment (TME) and the limited penetration of the NIR-I light in biological tissues compromise the efficacy of photothermal therapy (PTT) and photodynamic therapy (PDT) on tumors. Here, we developed a chlorin e6 (Ce6) and MnO2-coloaded, hyaluronic acid (HA)-coated single-walled carbon nanohorns (SWNHs) nanohybrid (HA-Ce6-MnO2@SWNHs) for PDT and PTT combination therapy of tumors. The nanohybrid could efficiently accumulate in tumors through CD44-mediated active targeting. The sequential MnO2-enhanced PDT and efficient NIR-II PTT had a remarkable therapeutic effect by eliminating the primary tumor and simultaneously inhibiting tumor recurrence.

Correlation between Serum Magnesium Level and Cardiac Valve Calcification in Patients with Chronic Kidney Disease.

BACKGROUND: The aim of the study was to investigate the correlation between serum magnesium (Mg) level and cardiac valve calcification (CVC) in patients with chronic kidney disease (CKD). METHODS: A total of 232 CKD patients hospitalized from August 2016 to December 2020 were divided into CVC and non-CVC groups. Their clinical data and laboratory examination results were compared, the risk factors for CVC in CKD patients were explored using logistic regression analysis, and Spearman's method was used to analyze the correlation between serum Mg level and CVC degree. According to the tertiles of mean serum Mg level, they were assigned into low serum Mg group (≤ 0.96 mmol/L), middle serum Mg group (0.97 - 1.07 mmol/L), and high serum Mg group (≥ 1.08 mmol/L). The relationship of serum Mg level with CVC risk in CKD patients was analyzed through the Cox regression model, and a prediction model was established using independent risk factors. RESULTS: Long CKD duration, low serum Mg level, high serum phosphorus (P) level, and high CKD stage were independent risk factors for CVC. Serum Mg level was significantly negatively correlated with the severity of CVC (r = -0.743, p < 0.05). The risk of CVC was significantly higher in low serum Mg group than that in high serum Mg group [hazard ratio (HR) = 2.852, 95% confidence interval (CI): 1.325 - 6.432, p = 0.005]. A CVC prediction model was established based on independent risk factors as follows: CVC predictive value = EXP [0.491 - 0.546 (CKD duration) - 0.454 (serum P level) + 2.145 (serum Mg level) - 0.812 (CKD stage)]/1 + EXP [0.491 - 0.546 (CKD duration) - 0.454 (serum P level) + 2.145 (serum Mg level) - 0.812 (CKD stage)]. The area under curve of the model was 0.750 (95% CI: 0.822 - 0.965), and that of the CVC prediction model for CKD patients in test set was 0.774 (95% CI: 0.761 - 0.975), showing no significant difference from that in training set (p > 0.05). CONCLUSIONS: Low serum Mg level serves as an independent risk factor for CVC in CKD patients, and may increase the risk of CVC. Therefore, the serum Mg level in CKD patients should be corrected timely in clinical practice.

One-pot synthesis of 68Ga-doped ultrasmall gold nanoclusters for PET/CT imaging of tumors.

Gold nanoclusters (AuNCs) have attracted much attention for tumor theranostics in recent years because of their ability of renal clearance and to escape the reticuloendothelial system (RES) sequestration. In this study, we presented a novel method to synthesize 68Ga-doped (labeled) AuNCs by simultaneous reduction of 68GaCl3 and HAuCl4 by glutathione. As synthesized 68Ga-doped, glutathione-coated AuNCs (68Ga-GSH@AuNCs) were ultrasmall in size (<2 nm), highly stable under physiological conditions and renally clearable, and had high efficiency for tumor targeting. To demonstrate the universality of this 68Ga labeling method and further enhance tumor targeting efficiency, arginine-glycine-aspartate (RGD)-containing peptide was introduced as co-reductant to synthesize RGD peptide and glutathione co-coated, 68Ga-labeled AuNCs (68Ga-RGD-GSH@AuNCs). Introduction of RGD peptide did not interfere the synthesis process but significantly enhanced the tumor targeting efficiency of the AuNCs. Our study demonstrated that it was feasible to label AuNCs with gallium-68 by direct reduction of the radioisotope and HAuCl4 with reductant peptides, holding a great potential for clinical translation for PET/CT detection of tumors.

Dual Targeting of Endoplasmic Reticulum by Redox-Deubiquitination Regulation for Cancer Therapy.

BACKGROUND: Recently, nanocatalyst-induced endoplasmic reticulum (ER) stress for cancer therapy has been attracting considerable attention. However, cancer cells are often able to overcome ER stress-induced death by activating the unfolded protein response (UPR), making nanocatalytic monotherapy a poor defense against cancer progression. PURPOSE: In this study, to improve the nanocatalytic treatment efficacy, a phase change material (PCM) was used to encapsulate the upstream ER stress initiator, iron oxide nanoparticles (Fe3O4 NPs), and the downstream UPR modulator, PR-619. Subsequently, the tumor-homing peptide tLyP-1 was coupled to it to form tLyP-1/PR-619/Fe3O4@PCM (tPF@PCM) theranostic platform. MATERIALS AND METHODS: tPF@PCM was synthesized using nanoprecipitation and resolidification methods followed by the EDC/NHS cross-linking method. The targeting capacity of tPF@PCM was evaluated in vitro and in vivo using flow cytometry and magnetic resonance imaging, respectively. The therapeutic efficacy of tPF@PCM was investigated in a renal cell carcinoma mouse model. Moreover, we explored the synergistic anti-tumor mechanism by examining the intracellular reactive oxygen species (ROS), aggregated proteins, ER stress response levels, and type of cell death. RESULTS: tPF@PCM had excellent tumor-targeting properties and exhibited satisfactory photothermal-enhanced tumor inhibition efficacy both in vitro and in vivo. Specifically, the phase transition temperature (45 °C) maintained using 808 nm laser irradiation significantly increased the release and catalytic activity of the peroxidase mimic Fe3O4 NPs. This strongly catalyzed the generation of hydroxyl radicals (•OH) via the Fenton reaction in the acidic tumor microenvironment. The redox imbalance subsequently resulted in an increase in the level of damaged proteins in the ER and initiated ER stress. Moreover, the pan-deubiquitinase inhibitor PR-619 blocked the "adaptive" UPR-mediated degradation of these damaged proteins, exacerbating the ER burden. Consequently, irremediable ER stress activated the "terminal" UPR, leading to apoptosis in cancer cells. CONCLUSION: This ER stress-exacerbating strategy effectively suppresses tumorigenesis, offering novel directions for advances in the treatment of conventional therapy-resistant cancers.

Metabolic Control by Heat Stress Determining Cell Fate to Ferroptosis for Effective Cancer Therapy.

Flexible manipulation of the fate of cancer cells through exogenous stimulation-induced metabolic reprogramming could handle the cellular plasticity-derived therapies resistance, which provides an effective paradigm for the treatment of refractory and relapsing tumors in clinical settings. Herein, we demonstrated that moderate heat (45 °C) could significantly regress the expression of antioxidants and trigger specific lipid metabolic reprogramming in cancer cells synergized with iron oxide nanoparticles (Fe3O4 NPs). This metabolic control behavior destroyed the tumor redox homeostasis and produced overwhelming lipid peroxides, consequently sensitizing the tumor to ferroptosis. Based on these findings, a heat-triggered tumor-specific ferroptosis strategy was proposed by the rational design of a polypeptide-modified and 1H-perfluoropentane (1H-PFP)-encapsulated Fe3O4-containing nanoformulation (GBP@Fe3O4). When irradiated by an 808 nm laser, the phase transition of 1H-PFP was triggered by localized moderate heat (45 °C), leading to burst release of Fe3O4in situ to produce potent reactive oxygen species through the Fenton reaction in the tumor microenvironment. Together with the antioxidant inhibition response and distinctive lipid metabolic reprogramming by heat stress, this oxidative damage was amplified to induce tumor ferroptosis and achieve sufficient antitumor effects. Importantly, we confirmed that ACSBG1, an acyl-CoA synthetase, was the key pro-ferroptotic factor in this heat-induced ferroptosis process. Moreover, knockout of this gene could realize cancer cell death fate conversion from ferroptosis to non-ferroptotic death. This work provides mechanistic insights and practical strategies for heat-triggered ferroptosis in situ to reduce the potential side effects of direct ferroptosis inducers and highlights the key factor in regulating cell fate under heat stress.

NIR/photoacoustic imaging of multitype gallbladder cancer using carboxyl/amino functionalized polymer dots.

Gallbladder cancer has high incidence and mortality and a low early diagnosis rate and requires rapid and efficient diagnosis. Herein, carboxyl/amino functionalized polymer dots (Pdots) were designed to enhance cellular internalization and tumor accumulation. The prepared Pdots were 40-50 nm in diameter, contained no toxic metal, exhibited long circulation time and high stability, and produced strong NIR emission and photoacoustic signals. Different cellular uptake and distribution of functionalized Pdots in eight gallbladder cell lines were quantitatively investigated using flow cytometry and super-resolution microscopy. In vivo NIR fluorescence imaging showed that the functional Pdots had high accumulation in the tumor after 30 minutes of injection and remained there for up to 6 days. In addition, photoacoustic imaging found that the abundant blood vessels around the tumor microenvironment and Pdots entered the tumor through the blood vessels. Furthermore, a high heterogeneity of vascular networks was visualized in real-time and high resolution by probe-based confocal laser endomicroscopy imaging. These results offer a new avenue for the development of functional Pdots as a probe for multi-modal and multi-scale imaging of gallbladder cancer in small animals.

Sequential PDT and PTT Using Dual-Modal Single-Walled Carbon Nanohorns Synergistically Promote Systemic Immune Responses against Tumor Metastasis and Relapse.

Immune responses stimulated by photodynamic therapy (PDT) and photothermal therapy (PTT) are a promising strategy for the treatment of advanced cancer. However, the antitumor efficacy by PDT or PTT alone is less potent and unsustainable against cancer metastasis and relapse. In this study, Gd3+ and chlorin e6 loaded single-walled carbon nanohorns (Gd-Ce6@SWNHs) are developed, and it is demonstrated that they are a strong immune adjuvant, and have high tumor targeting and penetration efficiency. Then, three in vivo mouse cancer models are established, and it is found that sequential PDT and PTT using Gd-Ce6@SWNHs synergistically promotes systemic antitumor immune responses, where PTT stimulates dendritic cells (DCs) to secrete IL-6 and TNF-α, while PDT triggers upregulation of IFN-γ and CD80. Moreover, migration of Gd-Ce6@SWNHs from the targeted tumors to tumor-draining lymph nodes sustainably activates the DCs to generate a durable immune response, which eventually eliminates the distant metastases without using additional therapeutics. Gd-Ce6@SWNHs intervened phototherapies also generate durable and long-term memory immune responses to tolerate and prevent cancer rechallenge. Therefore, this study demonstrates that sequential PDT and PTT using Gd-Ce6@SWNHs under moderate conditions elicits cooperative and long-lasting antitumor immune responses, which are promising for the treatment of patients with advanced metastatic cancers.

Regulation of cancer-immunity cycle and tumor microenvironment by nanobiomaterials to enhance tumor immunotherapy.

In the past decade, we have witnessed the revolution in cancer therapy, especially in the rapid development of cancer immunotherapy. In particular, the introduction of nanomedicine has achieved great improvement in breaking the limitations of and immunological tolerance caused by clinic-approved immunotherapies (cancer vaccine, CAR-T, and immune checkpoint blockade) to enhance immunogenicity, antigen presentation and T lymphocyte infiltration for eradicating the primary tumors and distant metastases simultaneously. However, some fundamental but significant issues still need to be thoroughly clarified before the combination of nanomedicine and immunotherapy moves toward clinical translation such as biological safety and synergistic mechanisms of nanomaterials in the systematic immune responses. Therefore, in this review, the role of nanomaterials in cancer immunotherapy is summarized, mainly focusing on the effective activation and long-term stimulation of both the innate and the adaptive immune responses and regulation of or remodeling the tumor microenvironment, especially the tumor immunosuppressive microenvironment. Also, we elaborate on the targets and challenges of nanomaterials in the cancer-immunity cycle, summarize several main strategies to convert the cold tumor immune microenvironment to the hot one, and illustrate the progress in regulation of tumor immune microenvironment by targeting specific immunosuppressive cells. Finally, we prospect the nano-combined immunotherapy strategies in tumor-targeting, normalization of tumor immune environment and modification of macrophages. This article is characterized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Strategy to prevent cardiac toxicity induced by polyacrylic acid decorated iron MRI contrast agent and investigation of its mechanism.

Polyelectrolyte modified iron oxide nanoparticles have great potential applications for clinical magnetic resonance imaging (MRI) and anemia treatments, however, possible associated heart toxicity is rarely reported. Here, polyacrylic acid (PAA)-coated Fe3O4 nanoparticles (PION) were synthesized and lethal reactions appeared when it was applied in vivo. The investigation of underlying mechanism showed that PION could break electrolyte balance and further resulted in serious heart failure, which was observed under color doppler ultrasound and dynamic vector blood flow technique. The results demonstrated that PION had a strong absorption tendency for divalent ions and the maximum tolerated dose (MTD) was lower than 100 mg/kg. From electrocardiography (ECG), PION presented an obvious impact on CaV1.2 ion channel, which leading to fatal arrhythmia. An appropriate solution for preventing this deadly effect was pre-chelation Ca2+ (n (Ca): n (COOH) = 3: 8) to PION (PION-Ca), which displayed much higher cardiac and electrophysiological safety when sealing the binding point of divalent cation ions with PAA. The injection in Beagle dogs further confirmed the safety of PION-Ca. This study explored the mechanism and offered a solution for cardiac toxicity induced by PAA-coated nanoparticles, which guides for enhancing the safety of such polyelectrolyte decorated nanoparticles and provides assurance for clinical applications.

Tumor Chemo-Radiotherapy with Rod-Shaped and Spherical Gold Nano Probes: Shape and Active Targeting Both Matter.

The morphologies of gold nanoparticles (NPs) affect their tumor accumulation through enhanced permeability and retention effect. However, detailed information and mechanisms of NPs' characteristics affecting tumor accumulation are limited. The aim of this study is to evaluate the effects of shape and active targeting ligands of theranostic NPs on tumor accumulation and therapeutic efficacy, and to elucidate the underlying mechanism. Methods:αvß3 integrin-targeted, cisplatin-loaded and radioisotope iodine-125 labeled spherical and rod-shaped gold nano theranostic probes (RGD-125IPt-AuNPs and RGD-125IPt-AuNRs) with similar sizes were fabricated and characterized. The in vivo distribution and chemo-radio therapeutic efficacy against tumors of these newly developed probes were subsequently evaluated. Moreover, a physiologically based pharmacokinetic (PBPK) model was developed to characterize the in vivo kinetics of these probes at the sub-organ level, and to reveal the mechanism of NPs' shape and active targeting ligands effects on tumor accumulation. Result: Cisplatin and iodine-125 were loaded sequentially onto the NPs through a thin polydopamine coating layer on the NPs. Both RGD-125IPt-AuNPs and RGD-125IPt-AuNRs exhibited high specificity for αvß3 in vitro, with the rod-shaped probe being more efficient. The PBPK model revealed that rod-shaped gold NPs diffused more rapidly in tumor interstitial than the spherical ones. Tumor accumulations of non-targeted and rod-shaped RAD-125IPt-AuNRs was higher in short term (1 h post injection), but not pronounced and similar to that of non-targeted spherical RAD-125IPt-AuNPs in 24 h after intravenous injection, revealing that the NPs' shape did not have a significant impact on tumor accumulations through enhanced permeability and retention (EPR) effect in long-term. While for actively targeted NPs, in addition to a higher distribution coefficient, RGD-125IPt-AuNRs also had a much higher tumor maximum uptake rate constant than RGD-125IPt-AuNPs, indicating both the shape and active targeting ligands affected the tumor uptake of rod-shaped NPs. As a result, RGD-125IPt-AuNRs had a more effective inhibition of tumor growth than RGD-125IPt-AuNPs by chemo-radiationtherapy. Conclusion: Our study suggests that both the shape and active targeting ligands of gold NPs play important roles on tumor accumulation and chemo-radio therapeutic effect.

GE11-PDA-Pt@USPIOs nano-formulation for relief of tumor hypoxia and MRI/PAI-guided tumor radio-chemotherapy.

Radio-chemo combination therapy has synergetic therapeutic effects on tumors. However, the tumor microenvironment, e.g. hypoxia and elevated H2S levels, limits its treatment efficacy. In this study, we developed a cisplatin-loaded, poly dopamine-coated and GE11 peptide-conjugated multi-functional theranostic system (GE11-PDA-Pt@USPIOs) based on poly acrylic acid-coated ultra-small superparamagnetic iron oxide nanoparticles (PAA@USPIOs) for modulation of the tumor hypoxic microenvironment and magnetic resonance imaging/photoacoustic imaging (MRI/PAI) guided radio-chemotherapy of tumors. The thick PAA coating on the USPIOs allowed highly efficient cisplatin loading by complexing the carboxylic groups on PAA with activated cisplatin. A subsequent thin layer of polydopamine (PDA) encapsulation following drug loading provided a means of further surface functionalization; it endowed the particles with photo-thermal properties but did not impede release of the drug or iron ions. GE11-PDA-Pt@USPIOs had high specificity for EGFR-positive tumor cells, could catalyze decomposition of H2O2 to oxygen and exhibited radio-chemo synergetic therapeutic effects under hypothermia conditions in vitro. Once administered intravenously, MRI and PA imaging revealed that the probes were able to accumulate in tumors with high efficiency; this relieved the tumor hypoxic conditions, sensitizing the tumors to radiation therapy. As a result, radio-chemo combination therapy significantly inhibited tumor growth. Our study illustrates for the first time that USPIOs can relieve tumor hypoxia and that GE11-PDA-Pt@USPIOs are highly effective for radio-chemotherapy of EGFR-positive tumors.

Dual Chemodrug-Loaded Single-Walled Carbon Nanohorns for Multimodal Imaging-Guided Chemo-Photothermal Therapy of Tumors and Lung Metastases.

Tumor combination therapy using nano formulations with multimodal synergistic therapeutic effects shows great potential for complete ablation of tumors. However, targeting tumor metastases with nano structures is a major obstacle for therapy. Therefore, developing a combination therapy system able to target both primary tumors and their metastases at distant sites with synergistic therapy is desirable for the complete eradication of tumors. To this end, a dual chemodrug-loaded theranostic system based on single walled carbon nanohorns (SWNHs) is developed for targeting both primary breast tumors and their lung metastases. Methods: SWNHs were first modified simultaneously with poly (maleic anhydride-alt-1-octadecene) (C18PMH) and methoxypolyethyleneglycol-b-poly-D, L-lactide (mPEG-PLA) via hydrophobic-hydrophobic interactions and π-π stacking. Then cisplatin and doxorubicin (DOX) (2.9:1 molar ratio) were sequentially loaded onto the modified nanohorns in a noninterfering way. After careful examinations of the release profiles of the loaded drugs and the photothermal performance of the dual chemodrug-loaded SWNHs, termed SWNHs/C18PMH/mPEG-PLA-DOX-Pt, the dual drug chemotherapeutic and chemo-photothermal synergetic therapeutic effects on tumor cells were evaluated. Subsequently, the in vivo behavior and tumor accumulation of the drug-loaded SWNHs were studied by photoacoustic imaging (PAI). For chemo-photothermal therapy of tumors, 4T1 tumor bearing mice were intravenously injected with SWNHs/C18PMH/mPEG-PLA-DOX-Pt at a dose of 10 mg/kg b.w. (in SWNHs) and tumors were illuminated by an 808 nm laser (1W/cm2 for 5 min) 24 h post-injection. Results: DOX and cisplatin were loaded onto the modified SWNHs with high efficiency (44 wt% and 66 wt%, respectively) and released in a pH-sensitive, tandem and sustainable manner. The SWNHs/C18PMH/mPEG-PLA-DOX-Pt had a hydrodynamic diameter of 182 ± 3.2 nm, were highly stable in physiological environment, and had both dual drug chemotherapeutic (CI = 0.439) and chemo-photothermal synergistic antitumor effects (CI = 0.396) in vitro. Moreover, the dual drug-loaded SWNHs had a long blood half-life (10.9 h) and could address both the primary breast tumors and their lung metastases after intravenous administration. Consequently, chemo-photothermal combination therapy ablated the primary tumors and simultaneously eradicated the metastatic lung nodules. Conclusion: Our study demonstrates that SWNHs/C18PMH/mPEG-PLA-DOX-Pt is highly potent for chemo-photothermal combination therapy of primary tumors and cocktail chemotherapy of their metastases at a distant site.

miR-145 inhibits proliferation and migration of breast cancer cells by directly or indirectly regulating TGF-ß1 expression.

Studies have demonstrated low expression of miR-145 associated with cell proliferation and migration in a wide variety of tumors. Here, we studied the expression of miR-145 in relation to the occurrence and development of breast cancer. Total RNA from breast cancer tissue and corresponding adjacent normal tissue was extracted and used to detect miR-145 expression by quantitative real-time polymerase chain reaction (qRT-PCR). We also transfected breast cancer cells with hsa-miR-145 mimics, hsa-miR-145 inhibitor, mimics negative control (mimics NC) or inhibitor negative control (inhibitor NC). Cell proliferation was analyzed by colony formation assays and methyl thiazolyl tetrazolium assays. Cell proliferation in breast cancer cells was decreased after overexpression of miR-145 and increased following miR-145 suppression. Cell migration and invasion were assessed using Transwell and wound healing assays, respectively, and were also decreased after overexpression of miR-145 and increased after miR-145 suppression in breast cancer cells. Finally, western blot assays showed that overexpression of miR-145 inhibited expression of transforming growth factor-ß1 (TGF-ß1). Collectively, these data suggest that miR-145 may inhibit TGF-ß1 protein expression which may in turn contribute to tumor formation.

A Multifunctional Platform for Tumor Angiogenesis-Targeted Chemo-Thermal Therapy Using Polydopamine-Coated Gold Nanorods.

Image-guided combined chemo-thermal therapy assists in optimizing treatment time, enhancing therapeutic efficiency, and circumventing side effects. In the present study, we developed a chemo-photothermal theranostic platform based on polydopamine (PDA)-coated gold nanorods (GNRs). The PDA coating was thin; however, it significantly suppressed the cytotoxicity of the cetyltrimethylammonium bromide template and allowed high cisplatin loading efficiency, arginine-glycine-aspartic acid (RGD) peptide (c(RGDyC)) conjugation, and chelator-free iodine-125 labeling (RGD-125IPt-PDA@GNRs). While loaded cisplatin was released in a pH-sensitive manner, labeled 125I was outstandingly stable under biological conditions. RGD-125IPt-PDA@GNRs had a high specificity for αvß3 integrin, and consequently, they could selectively accumulate in tumors, as revealed by single photon emission computed tomography/CT imaging, and in target tumor angiogenic vessels, as shown by high-resolution photoacoustic imaging. As RGD-125IPt-PDA@GNRs targets tumor angiogenesis, it is a highly potent tumor therapy. Combined chemo-photothermal therapy with probes could thoroughly ablate tumors and inhibit tumor relapse via a synergistic antitumor effect. Our studies demonstrated that RGD-125IPt-PDA@GNRs is a robust platform for image-guided, chemo-thermal tumor therapy with outstanding synergistic tumor killing and relapse inhibition effects.

Gold nanoparticles-based SPECT/CT imaging probe targeting for vulnerable atherosclerosis plaques.

In order to realize accurate localization and precise evaluation of vulnerability of atherosclerotic plaques via dual-modal imaging, gold nanoparticles (GNPs) were firstly caped with a thin amino-PEGs cover and then conjugated with the targeting molecular Annexin V and radionuclide Tc-99m simultaneously to form SPECT/CT imaging probe targeting apoptotic macrophages. The as-synthesized (99m)Tc-GNPs-Annexin V was with uniform size (30.2 ± 2.9 nm) and high labeling rate (98.9 ± 0.5%) and stability. Targeting ability of Annexin V for apoptotic macrophages was kept and enhanced. For macrophages with 30% apoptosis, cellular uptakes of 3.52 ± 0.35% for (99m)Tc-GNPs-Annexin V, 2.41 ± 0.53% for (99m)Tc-GNPs and 1.68 ± 0.36% for (99m)Tc-Annexin V were achieved after 2 h incubation. ApoE knock out mice with high fat diet-induced atherosclerosis were scanned via (99m)Tc-GNPs-Annexin V SPECT/CT. With the introduction of targeting molecules, imaging probe was more efficient in accumulating in apoptotic macrophages. In practical evaluation, CT helps to restrict the lesions depiction more accurately, meanwhile, SPECT imaging intensity correlated with pathological changes tightly. In conclusion, Annexin V-modified hybrid gold nanoparticles were successfully synthesized, and this imaging system helped to better localize and diagnose those vulnerable AS plaques via specific targeting the apoptotic macrophages.

Tumor Angiogenesis Targeted Radiosensitization Therapy Using Gold Nanoprobes Guided by MRI/SPECT Imaging.

Gold nanoparticles (AuNPs) have recently garnered great interest as potential radiosensitizers in tumor therapy. However, major challenges facing their application in this regard are further enhancement of tumor accumulation of the particles in addition to enhanced permeability retention (EPR) effect and an understanding of the optimal particle size and time for applying radiotherapy after the particle administration. In this study, we fabricated novel cyclic c(RGDyC)-peptide-conjugated, Gd- and 99 mTc-labeled AuNPs (RGD@AuNPs-Gd99 mTc) probes with different sizes (29, 51, and 80 nm) and evaluated their potential as radiosensitization therapy both in vitro and in vivo. We found that these probes have a high specificity for αvß3 integrin positive cells, which resulted in their high cellular uptake and thereby enhanced radiosensitization. Imaging in vivo with MRI and SPECT/CT directly showed that the RGD@AuNPs-Gd99 mTc probes specifically target tumors and exhibit greater accumulation within tumors than the RAD@AuNPs-Gd99 mTc probes. Interestingly, we found that the 80 nm RGD@AuNPs-Gd99 mTc probes exhibit the greatest effects in vitro; however, the 29 nm RGD@AuNPs-Gd99 mTc probes were clearly most efficient in vivo. As a result, radiotherapy of tumors with the 29 nm probe was the most potent. Our study demonstrates that RGD@AuNPs-Gd99 mTc probes are highly useful radiosensitizers capable of guiding and enhancing radiation therapy of tumors.

miR-21: A gene of dual regulation in breast cancer.

Breast cancer is characterized by an elevated capacity for tumor invasion and lymph node metastasis, but the cause remains to be determined. Recent studies suggest that microRNAs (miRNAs) can regulate the evolution of malignant behavior by regulating multiple target genes. A key oncomir in carcinogenesis is miR-21, which is consistently upregulated in a wide range of cancers. However, few functional studies are available for miR-21, and few targets have been identified. In this study, we explored the role of miR-21 in human breast cancer cells and searched for miR-21 targets.Total RNA from breast cancer tissue and corresponding adjacent normal tissue was extracted and used to detect miR-21 expression by quantificational real-time polymerase chain reaction (qRT-PCR), followed by analysis of the correlation between gonad hormone indices in peripheral blood and miR-21 expression in cancerous tissues from the same patients. Cell proliferation, colony formation, migration and invasion were then examined to determine the role of miR-21 in regulating breast cancer cells. Finally, western blotting was performed to determine if miR-21 regulated expression of signal transducers and activators of transcription 3 (STAT3), and assays of cell proliferation, colony formation, migration and invasion were performed to examine the role of STAT3 in regulation of breast cancer cells. We found that expression of miR-21 increased from normal through benign to cancerous breast tissues. Enhanced miR-21 expression was associated with serum levels of follicle-stimulating hormone, estradiol, ß-human chorionic gonadotropin, testosterone and prolactin in patients with breast cancer. Furthermore, cell proliferation, colony formation, migration and invasion were increased after overexpression of miR-21 in breast cancer cells and reduced by miR-21 suppression. In addition, we identified a putative miR-21 binding site in the 3'-untranslated region of the STAT3 gene using an online bioinformatical tool. We found that protein expression of STAT3 was significantly downregulated when breast cancer cells were transfected with miR-21 mimics, and was significantly upregulated in breast cancer cells transfected with a miR-21 inhibitor. Finally, we found that cell proliferation, colony formation, migration and invasion were decreased by treatment with 2.5 nM of Stattic, an inhibitor of STAT3 activation. Our data suggest that miR-21 expression is increased in breast cancer and plays an important role as a tumor gene by targeting STAT3, which may act as a double-response controller in breast cancer.