Objectives:Sirtuin 6 (SIRT6) is a longevity-associated gene with recognized therapeutic potential for vascular aging through the regulation of vascular smooth muscle cells (VSMCs) senescence. This study aims to develop a visualized nanodelivery system for a SIRT6 activator to attenuate vascular aging in a mouse model. Methods:The expression of the vascular aging marker, osteopontin (OPN), was detected by Western blot and histological staining in the aortas of naturally aging C57BL/6 mice. The SIRT6 activator MDL800 and the near-infrared (NIR) agent indocyanine green (ICG) were encapsulated by poly(caprolactone)-poly(ethylene glycol) (PCL-PEG), which was modified with OPN-targeting peptides, to construct OPN-targeting micelles loaded with MDL800 and ICG (OPN-MI). Particle size and zeta potential were assessed using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The biocompatibility and in vitro NIR signals were evaluated in senescent VSMCs. NIR fluorescence imaging was then performed to visualize the temporal variation and biodistribution of OPN-MI micelles in aging vessels. After 8 weeks of intravenous injection into naturally aging mice, bioinformatics analysis, pulse wave velocity (PWV) measurement, pathological staining, and molecular biological experiments were conducted to explore the anti-aging mechanism of OPN-MI micelles. Results:The expression of OPN in the aortas of naturally aging mice was significantly higher than that in control mice (p < 0.001), confirming OPN as a target for vascular aging. The OPN-MI micelles exhibited a particle size of 107.008 ± 9.572 nm and a zeta potential of -7.293 ± 2.291 mV. These micelles demonstrated excellent biocompatibility, and their strength of NIR fluorescence signals increased proportionally with the concentration of OPN-MI micelles. In vivo and ex vivo NIR fluorescence imaging revealed that OPN-MI micelles accumulated significantly in the arterial walls of aged mice compared to MI micelles (p < 0.001). Bioinformatics analysis and validation showed that MDL800 reduced MMP9 expression by activating SIRT6 to deacetylate H3K9ac and H3K56ac. After 8 weeks of injection, the PWV of abdominal aortas in the OPN-MI micelles group decreased (p = 0.031), the number of elastin breaks in the OPN-MI micelles group was reduced (p = 0.016), and the intimal-medial thickness in the OPN-MI micelles group was alleviated (p = 0.048) compared to the aged group. Mechanistically, OPN-MI micelles reduced MMP9 expression (p = 0.001) through SIRT6 deacetylation. Conclusions:The visualized OPN-targeted micelles encapsulating MDL800 and ICG effectively attenuate vascular aging in a naturally aging mouse model. This delivery system holds promise as a therapeutic strategy for delaying vascular aging in the future.

Cardiac amyloidosis (CA) is characterized by the deposition of the misfolded amyloid precursor proteins in the myocardium of the heart. The systemic form of CA is mainly caused by either the mis-folded monoclonal immunoglobulin light chains (kappa and lambda) or transthyretin.[1]The clinical manifestations are mainly overlap with symptoms of other cardiovascul-ar diseases mostly hypertrophic cardiomyopathy and he-art failure. Some cases often overlooked and remains un-diagnosed because of the atypical clinical manifestations,especially in the elderly. The incidence of CA has incre-ased across the world recently.[2]This paper reports the di-agnosis and treatment of an elderly male patient with wi-ld-type transthyretin CA (ATTRwt-CA). Combined with the standardized diagnosis procedure of CA,it can impr-ove the understanding and diagnosis of CA among cardi-ovascular physicians.

Atherosclerosis management heavily relies on the suppression of the inflammatory response of macrophages. Colchicine's potent anti-inflammatory properties make it a promising candidate for secondary prevention against cardiovascular disease. However, its high toxicity and numerous adverse effects limit its clinical use. To address this, there is an urgent need for specific drug delivery systems to boost the level of accumulation of colchicine within atherosclerotic plaques. In this study, the cluster of differentiation-44 receptor was verified to be overexpressed in inflammatory macrophages within plaques both in vitro and in vivo. Subsequently, a Prussian blue-based nanomedical loading system with hyaluronic acid (HA) coating was constructed, and its effects were observed on the atherosclerosis regression. Colchicine and Cy5.5 were encapsulated within Prussian blue nanoparticles through self-assembly, followed by conjugation with hyaluronic acid to create col@PBNP@HA. The formulated col@PBNP@HA displayed a cubic shape and scattered distribution. Importantly, col@PBNP@HA demonstrated specific cellular uptake into lipopolysaccharide-stimulated macrophages. In vitro experiments showed that col@PBNP@HA more effectively inhibited expression of inflammatory factors and scavenged reactive oxygen species compared with the control group, which were treated with colchicine. Furthermore, col@PBNP@HA exhibited its specific and higher accumulation in aortic plaque analysis via fluorescence imaging of aortas. After 4 weeks, administration of col@PBNP@HA resulted in significant atherosclerosis regression in the mice model, with therapeutic effects superior to those of free colchicine. Similar to colchicine, col@PBNP@HA inhibited the secretion of inflammation factors and scavenged ROS through the regulation of the toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (Myd88)/nuclear factor kappa-B (NF-κB) and peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) signaling pathway. In summary, col@PBNP@HA demonstrated specific targeting ability to inflammatory plaques and exerted beneficial effects on atherosclerosis regression through TLR4/Myd88/NF-κB and PGC-1α modulation.

BackgroundAcute thrombotic events play a major role in various cardiovascular diseases. Therefore, direct thrombus imaging can be proved beneficial for early diagnosis and prompt therapy of thrombosis. Our study investigated targeted dual‐modality cyclic arginine‐glycine‐aspartic micro bubbles (cRGD‐MBs) for direct imaging of thrombi by fluorescence and ultrasound.MethodscRGD‐MBs were prepared by mechanical vibration and chemical chelation methods.ResultsCoulter counter analysis demonstrated that the cRGD‐MBs were well dispersed, with diameters ranging from 1 to 3 μm. They emitted bright red fluorescence under an excitation wavelength of 660 nm. In vivo fluorescence and ultrasound imaging revealed that cRGD‐MBs accumulated at the site of thrombus in the carotid artery with significant fluorescence and ultrasonic signal.ConclusionsThis study showed that novel microbubble cRGD‐MBs were successfully synthesized, and that these could potentially be used as contrast agents for immediate diagnosis of acute thrombus in vivo.

ATP-binding cassette transporter A1 (ABCA1) plays a crucial role in atherosclerotic formation through mediated cholesterol efflux in macrophage-derived foam cells. In this study, a scavenger receptors AI (SR-AI) targeted theranostic nanoparticles was constructed for atherosclerosis regression via ABCA1 activation in foam cells. ABCA1-upregulator 5242331 and IR780 were encapsulated in PLGA-PEG micelles which were conjugated with SR-AI targeting peptide (PP1) to formulate the nanoparticles (SAU-NPs). Immunostaining revealed that SR-AI was highly expressed both in macrophage foam cells and in atherosclerotic plaque of ApoE-/- mice. The SAU-NPs have shown more active targeting to plaque lesion with higher stability compared with non-SR-AI targeted nanoparticles. The transformation from macrophage to foam cells was inhibited by SAU-NPs carried 5242331. Cholesterol deposition was effectively reduced in foam cells by SAU-NPs through activating the LXRα-ABCA1/ABCG1/SR-BI pathway. In conclusion, theranostic SAU-NPs which carried ABCA1-upregulator 5242331 exert beneficial effects on atherosclerosis regression via LXRα activation.

Angiogenesis plays a major role in atherosclerotic plaque development and instability. Our study aims to develop a novel optical and magnetic resonance (MR) dual-modality molecular imaging probe to early detect unstable plaques in vivo by targeting biomarkers of angiogenesis in murine models of atherosclerosis (AS). Immunofluorescence and western blot were used to detect the expression of Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) in activated Human Umbilical Vein Endothelial Cells (HUVECs). After synthesis and identification of novel short peptide VRBP1-targeted VEGFR2, HUVECs were co-cultured with FITC-VRBP1 to test specific affinity of VRBP1. Then VRBP1-UCNPstargeting VEGFR2 were constructed by conjugating VRBP1 to the surface of NaGdF4:Yb,Er@NaGdF4 nanoparticles. The characterization of the nanoparticles was performed by transmission electron microscopy (TEM), distribution of size, hydrodynamic size, zeta potential, absorption spectra, emission spectra, imaging intensity of different concentrations, binding affinity and cytotoxicity of nanoprobes in vitro. The upconversion luminescence (UCL) and MR imaging were performed to identify unstable atherosclerotic plaque in ApoE−/− mice in vivo and ex vivo. Morphological staining was used to verify AS model and angiogenesis, and Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) was used to confirm accumulation of the nanoparticles after imaging. After induced by hypoxia and ox-LDL, the expression of VEGFR2 in activated HUVECs was enhanced. FITC-VRBP1 can specifically bind to the HUVECs. Characterization of the nanoparticles showed that particles size is uniform with a stable structure, specific optical and MR signal, good binding affinity to VEGFR2 and low cytotoxicity. In vivo and ex vivo UCL imaging and quantitative analysis revealed that distinctive optical signal was observed in the regions of left carotid common arteries (LCCAs) of AS group after injection of VRBP1-UCNPs. Higher signal intensity on T1-weighted MR imaging appeared in the LCCA wall of AS group after injection. The results of morphological staining demonstrated angiogenesis in the atherosclerotic plaques, Gd ions in LCCAs, aortic arch and renal arteries bifurcations detected by ICP-AES confirmed accumulation of the nanoparticles in plaque. We successfully design and synthesize a novel UCNPs using peptide VRBP1 targeting to VEGFR2. In vivo imaging demonstrates that VRBP1-UCNPs can be used to perform optical/MR dual-modality imaging targeting angiogenesis in plaques, which is a promising technique to early detect unstable atherosclerosis.

目的 应用凝血酶智能响应型纳米探针,实现颈动脉血栓的体内可视化预测,为血栓形成的早期诊断提供新策略.方法 将超顺磁性氧化铁与凝血酶响应肽及Cy5.5-N-羟基琥珀酰亚胺酯(Cy5.5 NHS)共价偶联构建探针.检测不同浓度探针(0μg/ml、10 μg/ml、20 μμg/ml、50 μg/ml、100 μg/ml、200 μμg/ml)对人脐静脉内皮细胞的毒性.近红外荧光成像分析加入不同浓度凝血酶的探针荧光强度(实验组:凝血酶浓度分别为0.5 U/ml、1 U/ml、10 U/ml、50 U/ml;空白对照组为0 U/ml;阴性对照组为50 U/ml,并加入100 μg比伐芦定).制备小鼠颈动脉血栓模型,并对血栓组和对照组小鼠颈动脉组织切片进行免疫荧光染色,以探究探针的凝血酶靶向性.结果 不同探针浓度的细胞存活率比较无统计学差异(P＞0.05).不同浓度实验组探针荧光强度分别为空白对照组的17.64、34.24、55.01和64.65倍(P＜0.01),阴性对照组与空白对照组探针荧光强度比较无显著差异(P＞0.05).血栓组小鼠病变局部凝血酶水平较对照组显著升高.结论 本研究成功构建凝血酶智能响应型纳米探针,实现颈动脉血栓的早期精准识别,为血栓形成的可视化预测提供了新策略.

Vulnerable atherosclerotic plaque (VASPs) is the major pathological cause of acute cardiovascular event. Early detection and precise intervention of VASP hold great clinical significance, yet remain a major challenge. Photodynamic therapy (PDT) realizes potent ablation efficacy under precise manipulation of laser irradiation. In this study, we constructed theranostic nanoprobes (NPs), which could precisely regress VASPs through a cascade of synergistic events triggered by local irradiation of lasers under the guidance of fluorescence/MR imaging. The NPs were formulated from human serum albumin (HSA) conjugated with a high affinity-peptide targeting osteopontin (OPN) and encapsulated with photosensitizer IR780 and hypoxia-activatable tirapazamine (TPZ). After intravenous injection into atherosclerotic mice, the OPN-targeted NPs demonstrated high specific accumulation in VASPs due to the overexpression of OPN in activated foamy macrophages in the carotid artery. Under the visible guidance of fluorescence and MR dual-model imaging, the precise near-infrared (NIR) laser irradiation generated massive reactive oxygen species (ROS), which resulted in efficient plaque ablation and amplified hypoxia within VASPs. In response to the elevated hypoxia, the initially inactive TPZ was successively boosted to present potent biological suppression of foamy macrophages. After therapeutic administration of the NPs for 2 weeks, the plaque area and the degree of carotid artery stenosis were markedly reduced. Furthermore, the formulated NPs displayed excellent biocompatibility. In conclusion, the developed HSA-based NPs demonstrated appreciable specific identification ability of VASPs and realized precise synergistic regression of atherosclerosis.

Endotoxemia in sepsis remains a problem due to a lack of effective strategies. Our previous studies have demonstrated that melatonin (Mel) protects against ischemic heart injury and arteriosclerosis. However, its role in endotoxemia-exposed cardiomyocytes remains poorly understood. This study explored, for the first time, the protective effect of Mel on the pyroptosis of human stem cell-derived cardiomyocytes (hiPSC-CMs) exposed to lipopolysaccharide (LPS). Our results showed that treatment with 1 μM or 10 μM Mel for 12 h significantly improved 1 μg/ml LPS-induced hiPSC-CM injuries, as reflected by drastically decreased LDH release and increased cell viability, which was accompanied by the overt induction of autophagy. Specifically, Mel profoundly alleviated LPS-induced cell pyroptosis, as evidenced by decreased propidium iodide (PI) and active caspase-1 double-positive cell rates; suppressed the expression of NLRP3, cleaved caspase-1 (activated form of caspase-1), and GSDMD-NT (functional N-terminal fragment of GSDMD) expression; and inhibited the production of the cleaved IL-1β and cleaved IL-18 cytokines. Additionally, double-membrane autophagosomes were observed in LPS-injured hiPSC-CMs treated with 1 μM or 10 μM Mel. The hiPSC-CMs treated with LPS exhibited considerably fewer acidic vesicles (as revealed by LAMP1 staining) and autophagosomes (as revealed by LC3-II staining); however, Mel reversed this outcome in a dose-dependent manner. Furthermore, coincubation with rapamycin (an autophagy activator) or 3-MA (an autophagy inhibitor) accentuated and attenuated the antipyroptotic actions of Mel, respectively. Collectively, our findings demonstrate that Mel shields hiPSC-CMs against pyroptosis during endotoxemia by activating autophagy.

Current intravascular imaging modalities face hurdles in the molecular evaluation of progressed plaques. This study aims to construct a novel hybrid imaging system (intravascular ultrasound/intravascular photoacoustic, IVPA/IVUS) via RGDfk peptide-targeted nanoparticles for monitoring angiogenesis in progressed atherosclerotic plaques in a rabbit model. An atherosclerotic rabbit model was induced by abdominal aorta balloon de-endothelialization followed by a high-fat diet. A human serum albumin (HSA)-based nanoprobe modified with RGDfk peptide was constructed by encapsulating indocyanine green (ICG) via electrostatic force (ICG-HSA-RGDfk NPs, IHR-NPs). A hybrid intravascular imaging system that combined IVUS and IVPA was self-assembled for RGDfk visualization within atherosclerotic plaques in the rabbit abdominal aorta. Through IHR-NPs and the hybrid IVUS/IVPA imaging platform, multiple comprehensive pieces of information on progressed plaques, including anatomical information, composition information and molecular information, can be obtained simultaneously, which may improve the precise diagnosis of plaque characteristics and the evaluation of early interventions for atherosclerosis.

Early spontaneous detection of thrombin activation benefits precise theranostics for thrombotic vascular disease. Herein, a thrombin-responsive nanoprobe conjugated by a FITC dye, PEGylated Fe3O4 nanoparticles, and a thrombin-sensitive peptide (LASG) was constructed to visualize thrombin activation and subsequent thrombosis in vivo. The FITC dye was linked to the LASG coated on the Fe3O4 nanoparticles for sensing the thrombin activity via the Förster resonance energy transfer effect. In vitro fluorescence imaging showed that the fluorescence signal intensity increased significantly after incubation with thrombin in contrast to that of the control group (p < 0.05), and the signal intensity was enhanced with the increase in thrombin concentration. Further in vivo fluorescence imaging also revealed that the signal elevated markedly in the left common carotid artery (LCCA) lesion of the mice thrombosis model after nanoprobe injection, in contrast to that of the control + nanoprobe group (p < 0.05). Moreover, the thrombin inhibitor bivalirudin could decrease the filling defect of the LCCA. Three-dimensional fusion images of micro-CT and fluorescence confirmed that filling defects in the LCCA were nicely colocalized with fluorescence signal caused by nanoprobes. The nanoplatform based on a thrombin-activatable visualization system could provide smart responsive and dynamic imaging of thrombosis in vivo.

Aims This study investigated the association of circulating ceramides in patients with comorbid acute coronary syndrome and type 2 diabetes mellitus (ACS-DM). Methods A total of 761 patients with coronary heart disease who were admitted to the Department of Cardiology at the Chinese PLA General Hospital from March to August 2018 were enrolled in this study. Of these 761 patients, 282 were diagnosed with acute coronary syndrome (ACS). We selected 65 patients with ACS-DM (ACS-DM group; mean age 64.88 years; 38 men) and 65 patients with ACS but without any comorbidities (ACS group; mean age 64.68 years; 38 men); the two groups were matched by age and sex. We determined four circulating ceramides in 130 plasma samples: Cer(d18:1/16:0), Cer(d18:1/18:0), Cer(d18:1/24:1), and Cer(d18:1/24:0). The ceramides in plasma samples from patients with ACS and those from patients with ACS-DM were compared. Pearson correlation coefficients between individual ceramides and traditional cardiovascular risk factors for the whole study population were calculated. Multiple logistic regression models were used to evaluate the relativity between the ceramide and ACS-DM. Results Compared with the ACS group, the levels of Cer(d18:1/16:0), Cer(d18:1/18:0), and Cer(d18:1/24:1) and their ratios to Cer(d18:1/24:0) were higher in the ACS-DM group and Cer(d18:1/24:0) was lower in the ACS-DM group (P< 0.05). Correlation analysis demonstrated mild-to-moderate correlations of ceramide and traditional cardiovascular risk factors. There were relatively strong correlations of Cer(d18:1/18:0) and Cer(d18:1/24:1) with C-reactive protein, blood lipids, fasting blood glucose, and glycated hemoglobin A(1)c. In multiple logistic regression models, Cer(d18:1/18:0) [odds ratio (OR) 2.396; 95% confidence interval (CI) 1.103-5.205;P= 0.027], Cer(d18:1/24:1) (OR 2.826; 95% CI 1.158-6.896;P= 0.023), Cer(d18:1/18:0)/Cer(d18:1/24:0) (OR 2.242; 95% CI 1.103-4.555;P= 0.026), and Cer(d18:1/24:1)/Cer(d18:1/24:0) (OR 2.673; 95% CI 1.225-5.836;P= 0.014) were positively correlated with ACS-DM, and Cer(d18:1/24:0) (OR 0.200; 95% CI 0.051-0.778;P= 0.020) was negatively correlated with ACS-DM. Conclusion Circulating ceramides are positively correlated with the risk of ACS-DM comorbidity. These results give a new insight into the pathogenesis of ACS-DM comorbidity and could provide new options for risk estimation.

Pro-inflammatory M1 macrophage is identified as a prominent component initializing the progress of vulnerable atherosclerotic plaque. Here, we constructed anti-MARCO NaGdF4:Yb,Er@NaGdF4 upconversion nanoparticles (UCNPs) by conjugating polyclonal MARCO antibody to the surface of NaGdF4:Yb,Er@NaGdF4via condensation reaction. UCNPs displayed highly mono-dispersion with average sizes of 26.7 ± 0.8 nm and favorable biocompatibility. In vivo upconversion optical imaging revealed that distinctive fluorescence signal could be observed in the regions of carotid artery 10 min post-injection, reached peak value at 1 h and decreased back to baseline at 24 h post-injection. The carotid artery wall demonstrated high signal intensity on T1-weighted MR images after anti-MARCO UCNPs injection, as determined by 7.0T MRI. Immunofluorescence staining of tissue section of carotid artery revealed that MARCO was highly abundant in shoulder regions of plaque. Anti-MARCO UCNPs is a promising optical/MRI dual-modality imaging probe which can non-invasively reflect M1 phenotype macrophages behavior in vivo.

目的 通过构建基于人血清白蛋白(HSA)的光学纳米探针(ICG-HSA-OPN),靶向合成型平滑肌细胞,实现对动脉易损斑块的精准识别.方法 HSA耦联骨桥蛋白(OPN)活性短肽后,于水溶液中通过静电作用包载吲哚菁绿(ICG)自组装为纳米颗粒.用透射电镜和紫外光谱对探针进行表征,CCK-8实验检测探针对MOVAS细胞系的毒性,激光共聚焦显微镜观察细胞摄取能力.结果 纳米颗粒呈球形,粒径均一,大小约为20 nm;紫外光谱显示ICG已成功包载入HSA纳米探针,CCK-8结果表明不同浓度纳米探针(ICG 0～100μg/ml)的细胞存活率与对照组的差异无统计学意义(P≥0.05);激光共聚焦显微镜下可见靶向OPN纳米探针组细胞摄取能力明显强于非靶向组.结论 本研究成功构建了能够特异性靶向易损斑块内合成型平滑肌细胞的纳米探针,且生物相容好.

Accumulated pieces of evidence have proved the beneficial effects of melatonin on myocardial ischemia/reperfusion (MI/R) injury, and these effects were largely dependent on melatonin membrane receptor activation. In humans and other mammals, there are two types of melatonin receptors, including the melatonin receptor 1 (MT1, melatonin receptor 1a or MTNR1A) and melatonin receptor 1 (MT2, melatonin receptor 1b or MTNR1B) receptor subtypes. However, which receptor mediates melatonin-conferred cardioprotection remains unclear. In this study, we employed both loss-of-function and gain-of-function approaches to reveal the answer. Mice (wild-type; MT1 or MT2 silencing by in vivo minicircle vector; and those overexpressing MT1 or MT2 by in vivo AAV9 vector) were exposed to MI/R injury. Both MT1 and MT2 were present in wild-type myocardium. MT2, but not MT1, was essentially upregulated after MI/R Melatonin administration significantly reduced myocardial injury and improved cardiac function after MI/R Mechanistically, melatonin treatment suppressed MI/R-initiated myocardial oxidative stress and nitrative stress, alleviated endoplasmic reticulum stress and mitochondrial injury, and inhibited myocardial apoptosis. These beneficial actions of melatonin were absent in MT2-silenced heart, but not the MT1 subtype. Furthermore, AAV9-mediated cardiomyocyte-specific overexpression of MT2, but not MT1, mitigated MI/R injury and improved cardiac dysfunction, which was accompanied by significant amelioration of oxidative stress, endoplasmic reticulum stress, and mitochondrial dysfunction. Mechanistically, MT2 protected primary cardiomyocytes against hypoxia/reoxygenation injury via MT2/Notch1/Hes1/RORα signaling. Our study presents the first direct evidence that the MT2 subtype, but not MT1, is a novel endogenous cardiac protective receptor against MI/R injury. Medications specifically targeting MT2 may hold promise in fighting ischemic heart disease.

Because of the high mortality of coronary atherosclerotic heart diseases, it is necessary to develop novel early detection methods for vulnerable atherosclerotic plaques. Phenotype transformation of vascular smooth muscle cells (VSMCs) plays a vital role in progressed atherosclerotic plaques. Osteopontin (OPN) is one of the biomarkers for phenotypic conversion of VSMCs. Significant higher OPN expression is found in foam cells along with the aggravating capacity of macrophage recruitment due to its arginine-glycine-aspartate sequence and interaction with CD44. Herein, a dual-modality imaging probe, OPN targeted nanoparticles (Cy5.5-anti-OPN-PEG-PLA-PFOB, denoted as COP-NPs), is constructed to identify the molecular characteristics of high-risk atherosclerosis by ultrasound and optical imaging. Characterization, biocompatibility, good binding sensibility, and specificity are evaluated in vitro. For in vivo study, apolipoprotein E deficien (ApoE-/- ) mice fed with high fat diet for 20-24 weeks are used as atherosclerotic model. Ultrasound and optical imaging reveal that the nanoparticles are accumulated in the vulnerable atherosclerotic plaques. OPN targeted nanoparticles are demonstrated to be a good contrast agent in molecular imaging of synthetic VSMCs and foam cells, which can be a promising tool to identify the vulnerable atherosclerotic plaques.

Background: Macrophage infiltration plays a vital role in vulnerable atherosclerotic plaque (VASP) progression. Our previous work has demonstrated that osteopontin (OPN), overexpressed in foamy macrophages, could be a target for VASP detection. Photodynamic therapy (PDT) can kill foamy macrophages selectively via combining photosensitizer and illumination to generate reactive oxygen species (ROS). Herein, we constructed human serum albumin (HSA)-based nanomedicine (ICG/TPZ/HSA-Ce6-OPN) to achieve precise identification of VASP by optical/MR imaging as well as specific therapy against atherosclerosis (AS). Methods: Nanomedicines (NMs) were prepared by targeting OPN peptide, conjugating MRI contrast agent Ce6-Mn 2+ , encapsulating fluorescent dye (ICG) and hypoxia-activated drug tirapazamine (TPZ) (A). Characterization, toxicity, sensitivity and therapeutic effect were evaluated in vitro . For in vivo study, ApoE –/– mice were fed with a high-fat diet and a perivascular cuff was placed around carotid artery to establish VASP model. NMs were intravenously injected to obtain optical/MR imaging signal. The size and vulnerability of plaques were evaluated after 2 weeks administration of NMs. Results: The transmission electron microscopy image (B), fluorescence (FL) spectra and UV absorption spectra manifested the discoid-shaped NMs were well-prepared (C, D). Good binding specificity were confirmed according to cellular uptake analysis. CCK-8 assay showed excellent bio-compatibility and therapeutic effect during PDT. In vivo study revealed the NMs were accumulated in VASP (F, G). Conclusion: OPN targeted NMs indicates great potentials for precise identification and therapeutic effect on AS. However, PDT is constrained by the limited light-penetration depth in tissue, so plaques in deep-seated arteries can hardly be treated. Thus, further study is required to overcome light-penetration limitation.

Coronary heart disease is a prevalent and fatal killer caused by vulnerable atherosclerotic plaques (VASPs). However, the precise detection and treatment of VASPs remains a difficult challenge. Here, we present the development of noninvasive human serum albumin (HSA)-based theranostic nanomedicines (NMs) for the specific diagnosis and effective therapy of VASPs. Methods: The ICG/SRT@HSA-pept NMs were formulated to contain payloads of the near-infrared (NIR) fluorescent dye indocyanine green (ICG) and the sirtuin 1 (Sirt1) activator SRT1720, and modified with a peptide moiety targeting osteopontin (OPN). The in vivo atherosclerotic mouse model was established with the high-fat diet (HFD). The in vitro vascular smooth muscle cells (VSMCs) phenotypic switching was induced using the ox-LDL stimulation. Results: Due to the overexpression of OPN in activated VSMCs and VASPs, the targeted NMs specifically accumulated within the VASPs region after intravenous injection into the atherosclerotic mice, achieving the precise detection of VASPs. In addition, in the presence of SRT1720, the NMs could activate intracellular Sirt1 and activate an antiatherogenesis effect by inhibiting the phenotypic switching of VSMCs, which is an essential contributor to the vulnerability and progression of atherosclerotic plaques. After therapeutic administration of the ICG/SRT@HSA-pept NMs for two weeks, the physiological sizes and plaque compositions of VASPs were markedly improved. Furthermore, ICG/SRT@HSA-pept NMs-treated mice presented a more favorable plaque phenotype than that was observed in free SRT1720-treated mice, suggesting the enhanced delivery of pharmaceutical agents to the atherosclerotic lesions and improved therapeutic efficacy of NMs compared with free SRT1720. Conclusions: The theranostic ICG/SRT@HSA-pept NMs showed great potential for the precise identification and targeted treatment of atherosclerotic diseases.

The proliferation of vascular smooth muscle cells (VSMCs) is one of the key events during the progress of atherosclerosis. The activated liver X receptor (LXR) signalling pathway is demonstrated to inhibit platelet-derived growth factor BB (PDGF-BB)-induced VSMC proliferation. Notably, following PDGF-BB stimulation, the expression of intercellular adhesion molecule-1 (ICAM-1) by VSMCs increases significantly. In this study, anti-ICAM-1 antibody-conjugated liposomes were fabricated for targeted delivery of a water-insoluble LXR agonist (T0901317) to inhibit VSMC proliferation. The liposomes were prepared by filming-rehydration method with uniform size distribution and considerable drug entrapment efficiency. The targeting effect of the anti-ICAM-T0901317 liposomes was evaluated by confocal laser scanning microscope (CLSM) and flow cytometry. Anti-ICAM-T0901317 liposomes showed significantly higher inhibition effect of VSMC proliferation than free T0901317 by CCk8 proliferation assays and BrdU staining. Western blot assay further confirmed that anti-ICAM-T0901317 liposomes inhibited retinoblastoma (Rb) phosphorylation and MCM6 expression. In conclusion, this study identified anti-ICAM-T0901317 liposomes as a promising nanotherapeutic approach to overcome VSMC proliferation during atherosclerosis progression.