Targeted Chemo-Photodynamic Combination Platform Based on the DOX Prodrug Nanoparticles for Enhanced Cancer Therapy

Chemo-photodynamic combination therapy has been received widespread attention in cancer treatment due to its excellent characteristics, such as reducing the adverse side effects of chemo-drugs and improving the therapeutic effects for various cancers. In this study, RGD and DOX was conjugated to PEG by thiol-ene addition and Schiff's base reaction, respectively, to prepare the targeted and pH-sensitive antitumor prodrug nanoparticles (RGD-PEG-DOX NPs, RGD-NPs). Subsequently, the photosensitizer chlorin e6 (Ce6) was encapsulated into RGD-NPs, thus obtaining a simple and efficient chemo-photodynamic combination platform (RGD-PEG-DOX/Ce6 NPs, RGD-NPs/Ce6). This nanoparticle possessed high drug loading property of both the chemo-drug and photosensitizer and could simultaneously release them under the mild acidic microenvironment of cancer cells, which was expected to realize the synchronization therapy of chemotherapy and photodynamic therapy (PDT). Compared with free DOX and Ce6, RGD-NPs/Ce6 could significantly improve the cellular uptake capacities of DOX and Ce6, resulting in the increased contents of ROS in cancer cells and effective cytotoxicity for tumor cells (MDA-MB-231 cells and MCF-7 cells) upon a laser radiation. The in vivo experiment showed that RGD-NPs/Ce6 displayed superior tumor targeting, accumulation, and retention ability than the other groups (free DOX, free Ce6 and NPs/Ce6), and thus significantly enhancing the antitumor effect in vivo with a laser radiation. In addition, the cardiotoxicity induced by DOX was thoroughly wiped out after being loaded and delivered by the nanoparticles according to the pathological analysis. Therefore, the targeted chemo-photodynamic combination therapeutic platform may be a promising candidate for enhanced cancer therapy.

[Efficacy and safety of tertiary hospital guided and community-driven family self-help cardiac rehabilitation model]

Objective: To explore the efficacy and safety of tertiary hospital guided and community-driven family self-help cardiac rehabilitation model. Methods: This study was a prospective randomized controlled study, 80 patients from Beijing Electrical Power Hospital and Beijing Jingmei Group General Hospital with acute coronary syndrome were included from June to December 2015 and divided into 2 groups. Patients in rehabilitation group (n=52) received tertiary hospital(Peiking University Peoples' Hospital) guided and community-driven family self-help cardiac rehabilitation for 3 months, and patients in control group (n=28) received routine secondary treatment for 3 months. Following parameters including 6 minutes walk distance, score of life quality (evaluated by Short Form-12), score of anxiety (evaluated by Generalized Anxiety Disorder-7), score of depression (evaluated by Perceived Health Questionnaire-9), self-management competency (evaluated by questionnaire) were collected at baseline and after treatment for 3 months. Results: Compared with control group, 6 minutes walk distance was longer in rehabilitation group((60.2±6.8) meters vs. (24.9±10.5)meters, P<0.01). The difference values between after and before intervention of life quality scores((0.14±3.90)scores vs.(-7.44±5.85)scores, P>0.05), anxiety scores((-0.16±2.12 ) scores vs.(0.70±1.13)scores, P>0.05) and depression scores((-1.17±2.79) scores vs.(0.60±0.36)scores, P>0.05) were similar between the 2 groups. The amplification of patients with regular exercise (50.26% vs. 0, P<0.05), limit sugary foods usually and always (53.22% vs. 3.98%, P<0.05), eat 200-400 g fruits usually and always (78.61 % vs. 0, P<0.05), eat 300-500 g vegetables usually and always (9.74% vs. 0, P<0.05), and answering very confident to questions such as let the physicians know about your diseases (40.17% vs. 5.00%, P<0.05), know how to take medicines (44.52% vs. 5.00%, P<0.05), know how much exercise was right for yourself (26.43% vs.0, P<0.05) were significantly higher in rehabilitation group than in control group. There were no cardiac rehabilitation training related cardiovascular events. Conclusion: Tertiary hospital guided and community-driven family self-help cardiac rehabilitation model is an effective and safe management model of cardiovascular disease in chronic phase, and it is necessary to further expand the study population to verify the efficacy of this model.

Abstract P5-08-27: Treatment patterns and clinical outcomes in patients with hormone receptor (HR)+ HER2+ metastatic breast cancer and low vs high levels of HR positivity from the SystHERs Registry

Introduction In 2010, the cutoff for HR positivity in breast cancer was established as ≥1% of cells staining HR+, previously having varied from 1% to 10%. The impact of this change on treatment patterns and outcomes is poorly understood. SystHERs is a prospective, observational cohort registry of patients (pts) with HER2+ metastatic breast cancer (MBC) that commenced enrollment in 2012. To our knowledge, SystHERs is the largest registry to collect and analyze data for the HER2+ subgroup. We report baseline characteristics, treatment patterns, and early outcomes by %HR+ (1–9% vs 10–100%).

Methods SystHERs enrolled pts aged ≥18 years and within 6 months of HER2+ MBC diagnosis. For pts with locally-determined HR+ disease, defined as HR+ in primary or metastatic tissue, %HR+ is the highest percentage of ER+ or PR+ tissue in early breast cancer or MBC. The percentage of ER+ or PR+ cells was not reported for pts considered HR– by the investigator. Median overall survival (OS; Kaplan–Meier) and hazard ratios (Cox regression) were estimated.

Results As of Feb 1, 2016, data were available for 872 eligible pts with known HR status, of whom 608 (70%) had HR+ disease. Of the 608 pts, 53 (9%) had 1–9%HR+ and 496 (82%) had 10–100%HR+; %HR+ was not reported for 59 pts. Baseline characteristics were similar between %HR+ subgroups (Table 1).

As shown in Table 2, the 1–9%HR+ subgroup was less likely to receive first-line hormonal therapy (26%) than the 10–100%HR+ subgroup (56%). 87% and 79% of pts received chemotherapy, respectively.

Median time from MBC diagnosis was 16.5 months (range, 0.4–49.4 months). Median OS was not reached at the data cutoff. The number of deaths was 13 (25%) in the 1–9%HR+ subgroup, and 68 (14%) in the 10–100%HR+ subgroup (log-rank P=0.025). The OS hazard ratio (0.514, 95% CI 0.283–0.931) favored the 10–100%HR+ subgroup. OS did not differ significantly between pts with 1–9%HR+ vs HR– disease (log-rank P=0.582, hazard ratio 1.185, 95% CI 0.647–2.169).

Table 1. Baseline characteristics 1-9%HR+ (n=53)10-100%HR+ (n=496)HR– (n=264)Age at MBC diagnosis, median yrs (range)54 (30–86)57 (21–86)55 (28–88)Race, %   White838372Black151320Premenopausal, %282522ECOG performance status, %   04654441463942≥2878MBC diagnosis type, %   De novo404958Recurrent605142Visceral, %*686275*Non-hepatic abdominal, ascites, CNS, liver, lung, or pleural effusion sites of metastasis

Table 2. First-line treatment 1-9%HR+ (n=53)10-100%HR+ (n=496)HR– (n=264)HER2-targeted therapy, %969391Chemotherapy, %877989Hormonal therapy, %26564

Conclusions These preliminary observational data suggest potential differences in treatment patterns and survival outcomes in low vs moderate/high HR+ expressers, with the former being less likely to receive hormonal therapy (26% vs 56%). Furthermore, low HR positivity was associated with poorer OS and was similar to OS observed in pts with HR– disease.

Citation Format: Jahanzeb M, Tripathy D, Rugo H, Swain S, Kaufman PA, Mayer M, Hurvitz S, O'Shaughnessy J, Mason G, Yardley DA, Brufsky A, Chu L, Antao V, Beattie M, Yoo B, Cobleigh M. Treatment patterns and clinical outcomes in patients with hormone receptor (HR)+ HER2+ metastatic breast cancer and low vs high levels of HR positivity from the SystHERs Registry [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-08-27.

Abstract P5-08-24: How do real-world treatment patterns compare to guideline recommendations for first-line metastatic breast cancer patients in US community clinics?

Background:

Treatment (txt) guidelines are based on trial data from a small minority of patients (pts). Linked electronic health records (EHRs) are a novel approach to examine txt patterns and outcomes in larger and more generalizable populations. Given the increasing importance of real world data and real world outcomes, we utilized linked EHRs from a network of US community clinics to examine how real world txt patterns compare to metastatic breast cancer (mBC) txt guideline recommendations.

Methods:

The Flatiron database provides real world clinical data collected from EHRs used by US cancer care providers. The Flatiron network comprises ~15% of US cancer pts and is geographically and demographically diverse.

Using EHR from Jan 2016 mBC database, we evaluated first-line (1L) txt patterns in mBC by molecular subtype. Pts were selected if they received mBC txt within 60 days of mBC diagnosis between 01Jan2011-31Dec2015, had ≥2 visits within the Flatiron Network on or after 01Jan2013, and were ≥18 years (yrs). Analyses were conducted to describe pt and clinical characteristics and 1L txt by HER2 and/or hormone receptor (HR) status.

Results:

Among 2509 mBC pts identified, 58.9% were HR+/HER2-, 17.7% HER2+, 11.6% HR-/HER2- (triple negative, TNBC), 7.4% HER2 equivocal, and 4.3% 'not done/unknown HER2 status'. Txt patterns in the latter two groups were not analyzed. Selected pt and disease characteristics by subtype are shown in Table 1. Median follow-up since mBC diagnosis was 1.1 yrs (range 0-5 yrs). The 1L mBC txts by subtype are shown in Table 2. Pts with HR+/HER2- subtype were treated primarily with hormonal therapy (68%) and/or chemotherapy (chemo) (35%). Among HER2+ pts, the 1L mBC txt patterns include trastuzumab+pertuzumab with chemo (31%), trastuzumab with chemo (22%), trastuzumab with hormonal therapy (9%), ado-trastuzumab (4%), lapatinib with chemo (3%), and lapatinib with hormonal therapy (1%). For TNBC, the majority received chemo (95%), such as paclitaxel (21%), nab-paclitaxel (13%) and docetaxel (12%).

Conclusion:

This study advances our current understanding of real world 1L patterns of care by molecular subtype among mBC pts and how these compare to guideline recommendations. While the majority of pts are receiving therapy per guidelines, up to 22% of HER2+ of pts are not receiving targeted therapy in 1L mBC

Table 1. Patient and disease characteristics by subtypeN (%)HR+/HER2- (N=1479)HER2+ (N=445)TNBC (N=291)Age at mBC diagnosis (yrs), median (range)66 (24-85)60 (27-85)60 (33-85)Sex   Female1459 (99)441 (99)289 (99)Race   White995 (67)274 (62)168 (58)Black112 (8)44 (10)42 (14)Asian19 (1)14 (3)5 (2)Other179 (12)50 (11)36 (12)Missing173 (12)63 (14)40 (14)MBC type   De novo418 (28)172 (39)94 (32)Recurrent881 (60)225 (51)178 (61)Unknown180 (12)48 (11)19 (7)HR Status   Positive1479 (100)300 (67)--Negative--145 (33)291 (100)

Table 2. 1L mBC treatments by subtypeN (%)HR+/HER2- (N=1479)HER2+ (N=445)TNBC (N=291)Any Targeted Therapy*77 (5)346 (78)12 (4)Any Chemotherapy521 (35)283 (64)276 (95)Any Hormonal Therapy1010 (68)115 (26)16 (6)*Targeted therapy includes trastuzumab, pertuzumab, ado-trastuzumab emtansine, lapatinib and bevacizumab

Citation Format: Chu L, Yoo B, Carrigan G, Lai C, Beattie M, Reyes C. How do real-world treatment patterns compare to guideline recommendations for first-line metastatic breast cancer patients in US community clinics? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-08-24.

[Clinical analysis of 24 cases of aortic dissection during pregnancy]

Objective: To investigate the management and perinatal outcome of aortic dissection during pregnancy. Methods: 24 pregnant women with aortic dissection who delivered in Beijing Anzhen Hospital Affiliated to Capital Medical University from January 1st, 2006 to February 29th, 2016 were recruited. The clinical data, the management and the perinatal outcome were analyzed retrospectively. Results: (1) Clinical features: The average age of the patients was (29±4) years old. The clinical symptoms occurred from 5 gestational weeks to 1 month after delivery. The major symptoms were chest pain, and some complained migratory or radiating pains. There were 17 Stanford type A cases and 7 type B cases. The aortic widths were 2.9-10.0 cm, with the average of (5.6±1.7) cm. D-dimer level was 448-6 421 μg/L, with the average of (1 097±1 209) μg/L, and the fibrin degradation products were 4.1-52.1 mg/L, with the average of (10.2±9.5) mg/L.The white blood cell ranged (6.8-36.4)×10(9)/L, with the average of (29.4±4.2)×10(9)/L; and the neutrophil rate was 76.0%-97.6%, with the average of (84.6±6.3) %. (2) The treatment: ①19 patients underwent aorta surgeries. The surgeries included aortic root replacement with total aortic arch replacement plus stented elephant trunk implantation (Bentall+Sun's surgery), aortic root replacement (Bentall surgery), stent implantation, thoracic and abdominal aorta replacement. The aortic operation time of the 19 patients were 5 gestational weeks to 1 month after delivery. The relation between aortic operation and the termination of pregnancy: 4 patients underwent aorta surgery after termination of pregnancy, 9 patients had cesarean section and aorta surgery at the same time, 6 patients underwent aorta surgery before cesarean section. ② 5 patients did not receive arota surgery, 2 patients of type A dissection and 1 patient of type B dissection died before the surgery; 2 cases of type B dissection underwent conservative treatment. The termination time of pregnancy was 6-37 gestational weeks, with the average of (26±10) weeks. (3)Maternal and fetal outcomes: 20 patients survived after treatment (83%, 20/24) and 4 patients died (17%, 4/24). 10 cases were live births, including 4 full-term infants and 6 preterm premature infants. The birth weight of the neonates was 1 080-3 800 g, with the average of (2 302±764) g. Three of them were very low birth weight infants and 1 was low birth weight infant; 3 neonates had mild asphyxia. The neonates were followed up for 0.5 to 10 years, with the average time of (1.4±1.7) years. So far the infants' development was good. Conclusions: Pregnancy with aortic dissection is pernicious. Early identification, prompt diagnosis and prompt interventing of the vascular surgery are necessary to the safety of mother and fetus.

A novel H2O2responsive supramolecular hydrogel for controllable drug release

We reported a peptide-based supramolecular hydrogel possessing a gel–sol phase transition triggered by H₂O₂.

[Clinical analysis of 19 cases of pregnant women with rapid arrhythmia in the treatment of radiofrequency catheter ablation]

Objective: To investigate the risk of radiofrequency catheter ablation and maternal and infant in pregnant women with rapid arrhythmia during pregnancy. Methods: The clinical data of the 19 cases of pregnancy complicated with rapid arrhythmia were retrospectively analyzed and followed up, including the gestational week, the type of arrhythmia, the treatment, and the outcome of the mother and child in Beijing Anzhen Hospital of Capital Medical University from January 2002 to March 2016. Results: (1)Clinical characteristics: the ages of the 19 cases were(31±4)years old(ranged from 26 to 35 years old), the onset gestational ages were(21±4)weeks(ranged from 15 to 32 weeks).

CLINICAL SYMPTOMS

paroxysmal palpitation, chest tightness, dizziness, and blurred vision. Arrhythmia types: 1 case of atrial flutter and atrial tachycardia, 1 case of atrial flutter and atrial fibrillation, 1 case of atrial fibrillation, 3 cases of supraventricular tachycardia, 1 case of atrial tachycardia and supraventricular tachycardia, 4 cases of ventricular tachycardia, 3 cases of ventricular premature beats and ventricular tachycardia, and 5 cases of atrial tachycardia. All cases were treated by drugs, but all failed 2 cases of them were performed esophageal pacing and cardioversion and also failed.(2)Treatment plan: 19 cases after treatment of arrhythmia, completely terminated, the first 7 patients(from 2002 to 2014)were operated in a small amount of radiation under the guidance, the other 12 patients(after 2015)were carried out in the Ensite NavX mapping system, whichwere operated with zero radiation. Complications and adverse reactions: 1 case of uterine contraction end operation and was gived magnesium sulfate 3 days intravenous inhibition of uterine contractions, 1 case occurred vagal reflex caused by reduced blood pressure and was gived fluid infusion utill normal blood pressure.(3)Maternal and neonatal outcomes: in addition 1 case of pregnancy to give up, the remaining 18 cases were full-term pregnant women, including 4 cases of vaginal delivery and 14 cases of cesarean section. The survival neonates were followed up for 1 to 14 years, average(2.0 ± 2.9)years. The infants were well developed during the follow-up period. Conclution: Radiofrequency catheter ablation is a safe and effective method for the treatment of pregnancy complicated with rapid arrhythmia.

A rabbit model of cerebral microembolic signals for translational research: preclinical validation for aspirin and clopidogrel

Essentials Microembolic signal (MES) is an independent predictor of stroke risk in patients. A rabbit model of cerebral microembolic signals was established. Therapeutic efficacy was demonstrated for aspirin and clopidogrel on microembolic signals. Potential translational value of this preclinical model of MES was demonstrated.

SUMMARY

Objectives Cerebral microembolic signals (MESs) detected by transcranial Doppler (TCD) ultrasound constitute an independent predictor of stroke risk and prognosis. The aim of this study was to develop a novel preclinical model of MESs to facilitate translational research. Methods A clinical TCD ultrasound machine was used to detect MESs in the cerebral circulation of New Zealand White rabbits. Technical feasibility was assessed for the measurement of MESs in the middle cerebral artery (MCA) by TCD. FeCl3 -induced carotid arterial thrombosis was optimized for the generation of endogenous microemboli. Ascending doses of two antithrombotic agents (aspirin and clopidogrel) were evaluated individually and in combination for their effects on both arterial thrombosis and MESs in a 30% FeCl3 -induced carotid arterial thrombosis model, along with ex vivo functional assays. Results Dose-dependent FeCl3 -induced arterial thrombosis studies showed that 30% FeCl3 resulted in the most consistent and reproducible MESs in the MCA (3.3 ± 0.7 MESs h(-1) ). Ascending-dose studies showed that the effective doses for 50% inhibition (ED50 ) of thrombus formation, based on integrated blood flow and thrombus weight, respectively, were 3.1 mg kg(-1) and 4.2 mg kg(-1) orally for aspirin, and 0.3 mg kg(-1) and 0.28 mg kg(-1) orally for clopidogrel. The ED50 values for MES incidence were 12.7 mg kg(-1) orally for aspirin, and 0.25 mg kg(-1) orally for clopidogrel. Dual treatment with aspirin (5 mg kg(-1) ) and clopidogel (0.3 mg kg(-1) ) resulted in significant reductions in cerebral MESs (P < 0.05) as compared with monotherapy with either agent. Conclusions Our study demonstrated the successful establishment of the MES model in rabbits, and it may provide translational value for MESs and ischemic stroke research.

[Clinical treatment of infective endocarditis with vegetations in pregnant women and the outcomes of gestation]

OBJECTIVE

To investigate the clinical treatment of infective endocarditis with vegetations in pregnant women and the outcomes of the gestation.

METHODS

Nine cases of pregnant women diagnosed as infective endocarditis with vegetations in Beijing Anzhen Hospital, Capital Medical University from January 2001 to October 2015 were enrolled in retrospective analysis. Consultations were held by doctors from department of obstetrics, anesthesiology, cardiology, cardial surgery and extracorporeal circulation to decide the individualized treatment plan for the 9 cases of pregnant women after admissions. Clinical treatments including general treatment, anti-infection treatment, cardiac surgery, and termination of pregnancy surgery were completed through collaboration among related departments. The clinical characters, therapeutic regimens, maternal and neonatal outcomes of the 9 cases were analyzed.

RESULTS

(1) Clinical characters: the ages of the 9 cases of pregnant women were from 25 to 36 years old. The onset gestational ages were from 19 to 36 weeks.

CLINICAL SYMPTOMS

fever, cough, sputum and progressive anemia were the main symptoms. Patients had cyanosis of lips, could not lie on the back or even be orthopnea, when heart failure happened. Heart murmur was audible and splenomegaly was touched in physical examination. Blood cultures were positive. Basic heart disease types: 7 cases of congenital heart diseases included 2 cases of aortic insufficiency, 1 case of mitral insufficiency, 1 case of patent ductus arteriosus, 1 case of right ventricular outflow tract stenosis and 2 cases of ventricular septal defect.Two cases of rheumatic heart diseases included 1 case of mitral stenosis, 1 case of mitral stenosis after artificial disc changed and jammed. According to endocardial vegetations attached position there were 3 cases of mitral valve vegetations, 2 cases of pulmonary valve vegetations, 3 cases of aortic vegetations and 1 case of right ventricular outflow tract neoplasm. Preoperative heart function classification: 1 case of level Ⅱ, 3 cases of level Ⅲ, 5 cases of level Ⅳ. (2) TREATMENTS: general treatment included oxygen uptake, rest in bed, cardiac strengthen and diuretic therapy, etc. Combined and adequate antibiotics were applied in anti-infection treatment according to drug sensitive test. Nine cases of pregnant women were all performed surgical treatment of heart diseases and removal of the endocardial vegetations. Caesarean sections were performed for 2 cases in second trimester and for 7 cases in last trimester. Cardiac surgery and caesarean section were operated in 6 cases at the same time among 22-34 weeks of pregnancy. Cardiac surgery were respectively operated in 2 cases 11 days and 32 days after the caesarean section at 33, 37 weeks of pregnancy. While Cardiac surgery was operated (at 26 weeks of pregnancy) before the caesarean section (at 37 weeks of pregnancy) in another 1 case. (3) Maternal and neonatal outcomes: 7 cases of pregnant women were rescued successfully, while 2 cases of pregnant women were death. Postoperative heart function classification: 1 case of level Ⅰ, 2 cases of level Ⅱ, 4 cases of level Ⅲ and 2 cases of level Ⅵ. Neonatal survivals were 6 cases including 2case of full-term infants, 4 cases of preterm infants. Stillbirth or neonatal death were 3 cases, which included 2 cases performed caesarean section in second trimester and 1 case of very low weight infant who was given up treatment by family because of severe asphyxia. Followed up periods were from 1 to 7 years with an average time of (2.0±1.6) years. Infants and young children grew and developed well during the period of follow up.

CONCLUSIONS

The risk is extremely high of pregnancy with infective endocarditis with vegetations. But there is still a way to save the maternal and neonatal life by using a multidisciplinary collaboration formulation and implementation of individualized treatment plan and selecting the appropriate time for heart surgery and the termination of pregnancy.

cRGD-Modified Benzimidazole-based pH-Responsive Nanoparticles for Enhanced Tumor Targeted Doxorubicin Delivery

Finding a smart cancer drug delivery carrier with long blood circulation, enhanced cancer targeting, and quick drug release in tumors is critical for efficient cancer chemotherapy. Herein, we design a cRGD-polycarboxybetaine methacrylate-b-polybenzimidazole methacrylate (cRGD-PCB-b-PBBMZ) copolymer to self-assemble into smart drug-loaded nanoparticles (cRGD-PCM NPs) which can target αvβ3 integrin overexpressed cancer tissue by cRGD peptide unit and release drug quickly in cancer cells by protonation of benzimidazole groups. The outer PCB layer can resist protein adhesion, and there are only about 10% of proteins in mouse serum adhered to the surface of PCM NPs. With the pKa value of 5.08 of the benzimidazole units, DOX can be released from NPs in pH 5.0 PBS. cRGD-PCM NPs can bring more DOX into HepG2 cells than nontargeting PCM NPs, and there has high DOX release rate in HepG2 cells because of the protonation of benzimidazole groups in endosome and lysosome. MTT assay verifies that higher cellular uptake of DOX causes higher cytotoxicity. Furthermore, the results of ex vivo imaging studies confirm that cRGD-PCM/DOX NPs can successfully deliver DOX into tumor tissue from the injection site. Therefore, the multifunctional cRGD-PCM NPs show great potential as novel nanocarriers for targeting cancer chemotherapy.

Folic acid-targeted disulfide-based cross-linking micelle for enhanced drug encapsulation stability and site-specific drug delivery against tumors

Although the shortcomings of small molecular antitumor drugs were efficiently improved by being entrapped into nanosized vehicles, premature drug release and insufficient tumor targeting demand innovative approaches that boost the stability and tumor responsiveness of drug-loaded nanocarriers. Here, we show the use of the core cross-linking method to generate a micelle with enhanced drug encapsulation ability and sensitivity of drug release in tumor. This kind of micelle could increase curcumin (Cur) delivery to HeLa cells in vitro and improve tumor accumulation in vivo. We designed and synthesized the core cross-linked micelle (CCM) with polyethylene glycol and folic acid-polyethylene glycol as the hydrophilic units, pyridyldisulfide as the cross-linkable and hydrophobic unit, and disulfide bond as the cross-linker. CCM showed spherical shape with a diameter of 91.2 nm by the characterization of dynamic light scattering and transmission electron microscope. Attributed to the core cross-linking, drug-loaded CCM displayed higher Nile Red or Cur-encapsulated stability and better sensitivity to glutathione than noncross-linked micelle (NCM). Cellular uptake and in vitro antitumor studies proved the enhanced endocytosis and better cytotoxicity of CCM-Cur against HeLa cells, which had a high level of glutathione. Meanwhile, the folate receptor-mediated drug delivery (FA-CCM-Cur) further enhanced the endocytosis and cytotoxicity. Ex vivo imaging studies showed that CCM-Cur and FA-CCM-Cur possessed higher tumor accumulation until 24 hours after injection. Concretely, FA-CCM-Cur exhibited the highest tumor accumulation with 1.7-fold of noncross-linked micelle Cur and 2.8-fold of free Cur. By combining cross-linking of the core with active tumor targeting of FA, we demonstrated a new and effective way to design nanocarriers for enhanced drug encapsulation, smart tumor responsiveness, and elevated tumor accumulation.

Co-delivery of doxorubicin and curcumin by pH-sensitive prodrug nanoparticle for combination therapy of cancer

Ample attention has focused on cancer drug delivery via prodrug nanoparticles due to their high drug loading property and comparatively lower side effects. In this study, we designed a PEG-DOX-Cur prodrug nanoparticle for simultaneous delivery of doxorubicin (DOX) and curcumin (Cur) as a combination therapy to treat cancer. DOX was conjugated to PEG by Schiff's base reaction. The obtained prodrug conjugate could self-assemble in water at pH 7.4 into nanoparticles (PEG-DOX NPs) and encapsulate Cur into the core through hydrophobic interaction (PEG-DOX-Cur NPs). When the PEG-DOX-Cur NPs are internalized by tumor cells, the Schiff's base linker between PEG and DOX would break in the acidic environment that is often observed in tumors, causing disassembling of the PEG-DOX-Cur NPs and releasing both DOX and Cur into the nuclei and cytoplasma of the tumor cells, respectively. Compared with free DOX, free Cur, free DOX-Cur combination, or PEG-DOX NPs, PEG-DOX-Cur NPs exhibited higher anti-tumor activity in vitro. In addition, the PEG-DOX-Cur NPs also showed prolonged blood circulation time, elevated local drug accumulation and increased tumor penetration. Enhanced anti-tumor activity was also observed from the PEG-DOX-Cur-treated animals, demonstrating better tumor inhibitory property of the NPs. Thus, the PEG-DOX-Cur prodrug nanoparticle system provides a simple yet efficient approach of drug delivery for chemotherapy.

Quantum Transport and Observation of Dyakonov-Perel Spin-Orbit Scattering in Monolayer MoS_{2}

Monolayers of group 6 transition metal dichalcogenides are promising candidates for future spin-, valley-, and charge-based applications. Quantum transport in these materials reflects a complex interplay between real spin and pseudospin (valley) relaxation processes, which leads to either positive or negative quantum correction to the classical conductivity. Here we report experimental observation of a crossover from weak localization to weak antilocalization in highly n-doped monolayer MoS_{2}. We show that the crossover can be explained by a single parameter associated with electron spin lifetime of the system. At low temperatures and high carrier densities, the spin lifetime is inversely proportional to momentum relaxation time; this indicates that spin relaxation occurs via a Dyakonov-Perel mechanism.

A charge-adaptive nanosystem for prolonged and enhanced in vivo antibiotic delivery

A poly(β-amino ester)-based nanocarrier with the acid-dependent charge conversion characteristic prolonged and enhanced the in vivo vancomycin delivery.

c-MYC responds to glucose deprivation in a cell-type-dependent manner

Metabolic reprogramming supports cancer cells’ demands for rapid proliferation and growth. Previous work shows that oncogenes, such as MYC, hypoxia-inducible factor 1 (HIF1), have a central role in driving metabolic reprogramming. A lot of metabolic enzymes, which are deregulated in most cancer cells, are the targets of these oncogenes. However, whether metabolic change affects these oncogenes is still unclear. Here we show that glucose deprivation (GD) affects c-MYC protein levels in a cell-type-dependent manner regardless of P53 mutation status. GD dephosphorylates and then decreases c-MYC protein stability through PI3K signaling pathway in HeLa cells, but not in MDA-MB-231 cells. Role of c-MYC in sensitivity of GD also varies with cell types. c-MYC-mediated glutamine metabolism partially improves the sensitivity of GD in MDA-MB-231 cells. Our results reveal that the heterogeneity of cancer cells in response to metabolic stress should be considered in metabolic therapy for cancer.

Magnetic mediation effect of a C impurity in a Mn-doped Zn₁₂O₁₂ nanocluster: a case of multiple exchange interactions

The stability and exchange interaction mechanism of a doped Zn12O12 cluster with Mn and C atoms were investigated by first-principles calculations. For the Mn-doped Zn12O12 cluster, it is identified that a superexchange interaction deriving the hybridization between the Mn 3d(2/x)-2/y and O 2p(xy) orbitals dominates the Mn(↑)-Mn(↓) antiferromagnetic coupling, although a direct exchange interaction deriving the Mn-Mn bonding is also found. In order to turn the Mn spin state in the Mn-doped Zn12O12 cluster, C doping is undertaken to change the magnetic interactions of these impurities. It is proved that the C incorporation into the Mn-doped Zn12O12 cluster destroys the short-ranged antiferromagnetic coupling, where multiple exchange interactions take over, including the direct exchange interaction and the kinetic p-d exchange interaction partially due to the geometric distortion and surface effect with dangling bonds (sp(2)-like hybrids). It is concluded that the kinetic p-d exchange interaction plays a dominant role in Mn/C-doped Zn12O12 clusters.

RGD-modifided oncolytic adenovirus exhibited potent cytotoxic effect on CAR-negative bladder cancer-initiating cells

Cancer-initiating cell (CIC) is critical in cancer development, maintenance and recurrence. The reverse expression pattern of coxsackie and adenovirus receptor (CAR) and α_ν integrin in bladder cancer decreases the infection efficiency of adenovirus. We constructed Arg-Gly-Asp (RGD)-modified oncolytic adenovirus, carrying EGFP or TNF-related apoptosis-inducing ligand (TRAIL) gene (Onco^Ad.RGD-hTERT-EGFP/TRAIL), and applied them to CAR-negative bladder cancer T24 cells and cancer-initiating T24 sphere cells. Onco^Ad.RGD-hTERT-EGFP had enhanced infection ability and cytotoxic effect on T24 cells and T24 sphere cells, but little cytoxicity on normal urothelial SV-HUC-1 cells compared with the unmodified virus Onco^Ad.hTERT-EGFP. Notably, Onco^Ad.RGD-hTERT-TRAIL induced apoptosis in T24 cells and T24 sphere cells. Furthermore, it completely inhibited xenograft initiation established by the oncolytic adenovirus-pretreated T24 sphere cells, and significantly suppressed tumor growth by intratumoral injection. These results provided a promising therapeutic strategy for CAR-negative bladder cancer through targeting CICs.

Integrin-targeted pH-responsive micelles for enhanced efficiency of anticancer treatment in vitro and in vivo

The key to developing more nanocarriers for the delivery of drugs in clinical applications is to consider the route of the carrier from the administration site to the target tissue and to look for a simple design to complete this whole journey. We synthesized the amphiphilic copolymer cRGDfK-poly(ethylene glycol)-b-poly(2,4,6-trimethoxybenzylidene-1,1,1-tris(hydroxymethyl) ethane methacrylate) (cRGD-PETM) to construct multifunctional micelles. These micelles combined enhanced drug-loading efficiency with tumor-targeting properties, visual detection and controllable intracellular drug release, resulting in an improved chemotherapeutic effect in vivo. Doxorubicin (DOX) was encapsulated within the cRGD-PETM micelles as a model drug (termed as cRGD-PETM/DOX Ms). The size and morphology of the micelles were characterized systematically. As a result of the hydrophobic interaction and the π-π conjugation between the DOX molecules and the PTTMA copolymers, the cRGD-PETM/DOX Ms showed an excellent drug-loading capacity. The results of in vitro drug-release studies indicated that the cumulative release of DOX from cRGD-PETM/DOX Ms at pH 5.0 was twice that at pH 7.4. The results of fluorescent microscopic analysis showed that the cRGD-PETM/DOX Ms could be internalized by 4T1 and HepG2 cells via receptor-mediated endocytosis with rapid intracellular drug release, which resulted in increased cytotoxicity compared with free DOX. Ex vivo imaging studies showed that the cRGD-PETM/DOX Ms improved the accumulation and retention of the drug in tumor tissues. Studies of the in vivo anticancer effects showed that the cRGD-PETM/DOX Ms had a significantly higher therapeutic efficacy with lower side-effects than free DOX and PETM/DOX Ms. These results show that the multifunctional cRGD-PETM/DOX Ms have great potential as vehicles for the delivery of hydrophobic anticancer drugs.

Dynamic biostability, biodistribution, and toxicity of L/D-peptide-based supramolecular nanofibers

Self-assembling peptide nanofibers (including naturally L-amino acid-based and unnaturally D-amino acid-based ones) have been widely utilized in biomedical research. However, there has been no systematic study on their in vivo stability, distribution, and toxicity. Herein we systematically study the in vivo dynamic biostability, biodistribution, and toxicity of supramolecular nanofibers formed by Nap-GFFYGRGD (L-amino acid-based, L-fibers) and Nap-G(D)F(D)F(D)YGRGD (D-amino acid-based, D-fibers), respectively. The D-fibers have better in vitro and in vivo biostabilities than L-fibers. It is found that D-fibers keep a good integrity in plasma during 24 h, while half of l-fibers are digested upon incubation in plasma for 6 h. The biodistributions of L- and D-fibers are also studied using the iodine-125 radiolabeling technique. The results reveal that L-fibers mainly accumulate in stomach, whereas d-fibers preferentially distribute in liver. Successive administrations of both L- and D-fibers with the dose of 30 mg/kg/dose cause no significant inflammation, liver and kidney function damages, immune reaction, and dysfunction of hematopoietic system. This study will provide fundamental guidelines for utilization of self-assembling peptide-based supramolecular nanomaterials in biomedical applications, such as drug delivery, bioimaging, and regenerative medicine.