Real-Time Imaging of Free Radicals for Mitochondria-Targeting Hypoxic Tumor Therapy

Free radicals have emerged as new-type and promising candidates for hypoxic tumor treatment, and further study of their therapeutic mechanism by real-time imaging is of great importance to explore their biomedical applications. Herein, we present a smart free-radical generator AuNC-V057-TPP for hypoxic tumor therapy; the AuNC-V057-TPP not only exhibits good therapeutic effect under both hypoxic and normoxic conditions but also can monitor the release of free radicals in real-time both in vitro and in vivo. What is more, with the mitochondria-targeting ability, the AuNC-V057-TPP is demonstrated with improved antitumor efficacy through enhanced free radical level in mitochondria, which leads to mitochondrial membrane damage and ATP production reduction and finally induces cancer cell apoptosis.

[The role of ATA (2015) guidelines, superb microvascular imaging, and spectral Doppler in differentiation between malignant and benign thyroid nodules]

Objective:To evaluate the diagnostic value of ultrasound patterns of 2015 American Thyroid Association (ATA) guidelines, color Doppler flow imaging (CDFI), superb microvascular imaging (SMI), and spectral Doppler in the differentiation of benign and malignant thyroid nodules.Method:The study included 254 thyroid nodules confirmed by fine needle aspiration cytology (FNAC) or histopathologic examination. All nodules were detected by ultrasonography, SMI, CDFI and spectral Doppler respectively. Blood flow detection technologies (CDFI and SMI) were used to classify flow distribution characteristics of thyroid nodules according to Kim's grading criteria. The optimal threshold drawing from ROC curve is calculated to obtain the cut-off value of spectral Doppler.Result:①For benign solid nodules with peripheral flow distribution and malignant solid nodules with central blood flow distribution, the display rates of SMI are higher than those of the CDFI, the differences were statistically significant (P< 0.05). ②There was a significance difference in detecting benign and malignant nodules using spectral Doppler (P< 0.05). ③The specificity and accuracy of combinative modality 2015 ATA+SMI was significantly higher than that of ATA, SMI, and spectral Doppler. There was no significant difference between ATA+SMI and ATA+SMI+spectral Doppler for the sensitivity, specificity, and accuracy.Conclusion:SMI had a better detection rate of blood vessels than CDFI and contribute a certain value in differential diagnosis of benign and malignant thyroid nodules. The combination of 2015 ATA and SMI can improve diagnostic value in the differentiation between benign and malignant thyroid nodules.

[An analysis of coping styles and subjective well-being among nurses in the emergency treatment room of grade A tertiary hospitals in a province of China]

Objective: To investigate the coping styles and subjective well-being of nurses in the emergency treatment room of grade A tertiary hospitals in a province of China, and to explore the relationship between coping styles and subjective well-being. Methods: In January 2016, 189 nurses in the emergency treatment room were selected from 9 grade A tertiary hospitals in a province of China by random sampling. The general data, coping styles, and subjective well-being of these nurses were analyzed using the general questionnaire, coping style questionnaire, and Campbell index of well-being scale, respectively. Results: The total score of subjective well-being of nurses in the emergency treatment room was 7.54, and the subjective well-being was significantly different between the nurses with different professional titles and between those with different education levels (F=3.46 and 3.47, both P<0.05). The score of illusion coping style differed significantly across the nurses of different ages (F=5.17, P<0.05) , the scores of self-reproach, illusion, and withdrawal coping styles differed significantly across the nurses with different nursing years (F=3.99, 5.30, and 4.97, all P<0.05) , and the score of illusion coping style differed significantly across the nurses with different education levels (F=5.09, P<0.05). Most (71.9%) of the nurses in the emergency treatment room adopted the mature coping style. Subjective well-being was positively correlated with problem-solving, help-seeking, and rationalization (r=0.232, 0.018, and 0.167, all P<0.05) and negatively correlated with withdrawal (r=-0.146, P<0.05) . Conclusion: Most nurses in the emergency treatment room adopt the mature coping style. Their subjective well-being and coping style vary with different ages, nursing years, professional titles, and education levels, and the subjective well-being is relatively low.

Age Estimation and Age-related Facial Reconstruction of Xinjiang Uygur Males by Three-dimensional Human Facial Images

OBJECTIVES

To search age-correlated facial features and construct an age estimation model based on the three-dimensional （3D） facial images of Xinjiang Uygur males, and to structure individual face images of old age and young age.

METHODS

Pretreatment was performed to collect 105 3D facial images of Xingjiang Uygur males aged between 17-57 years by Artec Studio software. The facial images were transferred to high-density 3D dot matrix data by FaceAnalysis software, and each image could be represented with 32 251 vertexes. Central correction of the facial images was done and all the data were aligned to a standard coordinate frame by generalized Procrustes analysis （GPA）. The age estimation model was established by partial least square regression （PLSR）. Furthermore, the changes of age-correlated facial features were presented on the heat map of average face, and the reconstruction of facial images at different ages was performed based on this model.

RESULTS

With age, the average faces showed a series of changes including the nasolabial sulcus deepening, cheek sinking, cheekbone protruding and eye corner drooping. The Pearson correlation coefficient （r） between estimated age and chronological age was 0.71. The mean absolute deviation （MAD） of age estimation was 6.37 years. The results of age estimation in >30-40 years group showed a best accuracy （MAD=4.27 years）, and the deviations increased with age after 40 years. The composite facial images represented a significant result with age on facial morphological features and aging.

CONCLUSIONS

The results of this study reveal the age-correlated facial features and aging markers in Uygur population, which help to construct a reliable age estimation model.

Aggressive Man-Made Red Blood Cells for Hypoxia-Resistant Photodynamic Therapy

Extreme hypoxia of tumors represents the most notable barrier against the advance of tumor treatments. Inspired by the biological nature of red blood cells (RBCs) as the primary oxygen supplier in mammals, an aggressive man-made RBC (AmmRBC) is created to combat the hypoxia-mediated resistance of tumors to photodynamic therapy (PDT). Specifically, the complex formed between hemoglobin and enzyme-mimicking polydopamine, and polydopamine-carried photosensitizer is encapsulated inside the biovesicle that is engineered from the recombined RBC membranes. The mean corpuscular hemoglobin of AmmRBCs reaches about tenfold as high as that of natural RBCs. Owing to the same origin of outer membranes, AmmRBCs share excellent biocompatibility with parent RBCs. The introduced polydopamine plays the role of the antioxidative enzymes existing inside RBCs to effectively prevent the oxygen-carrying hemoglobin from the oxidation damage during the circulation. This biomimetic engineering can accumulate in tumors, permit in situ efficient oxygen supply, and impose strong PDT efficacy toward the extremely hypoxic tumor with complete tumor elimination. The man-made pseudo-RBC shows potentials as a universal oxygen-self-supplied platform to sensitize hypoxia-limited tumor treatment means, including but not limited to PDT. Meanwhile, this study offers ideas to the production of artificial substitutes of packed RBCs for clinical blood transfusion.

A Multifunctional Biomimetic Nanoplatform for Relieving Hypoxia to Enhance Chemotherapy and Inhibit the PD-1/PD-L1 Axis

Hypoxia is reported to participate in tumor progression, promote drug resistance, and immune escape within tumor microenvironment, and thus impair therapeutic effects including the chemotherapy and advanced immunotherapy. Here, a multifunctional biomimetic core-shell nanoplatform is reported for improving synergetic chemotherapy and immunotherapy. Based on the properties including good biodegradability and functionalities, the pH-sensitive zeolitic imidazolate framework 8 embedded with catalase and doxorubicin constructs the core and serves as an oxygen generator and drug reservoir. Murine melanoma cell membrane coating on the core provides tumor targeting ability and elicits an immune response due to abundance of antigens. It is demonstrated that this biomimetic core-shell nanoplatform with oxygen generation can be partial to accumulate in tumor and downregulate the expression of hypoxia-inducible factor 1α, which can further enhance the therapeutic effects of chemotherapy and reduce the expression of programmed death ligand 1 (PD-L1). Combined with immune checkpoints blockade therapy by programmed death 1 (PD-1) antibody, the dual inhibition of the PD-1/PD-L1 axis elicits significant immune response and presents a robust effect in lengthening tumor recurrent time and inhibiting tumor metastasis. Consequently, the multifunctional nanoplatform provides a potential strategy of synergetic chemotherapy and immunotherapy.

Hierarchical Micro-/Nanostructures from Human Hair for Biomedical Applications

With the prominent progress of biomedical engineering, materials with high biocompatibility and versatile functions are urgently needed. So far, hierarchical structures in nature have shed some light on the design of high performance materials both in concept and implementation. Inspired by these, the hierarchical micro-/nanostructures of human hair are explored and human hair is further broken into hierarchical microparticles (HMP) and hierarchical nanoparticles (HNP) with top-down procedures. Compared with commercialized carriers, such as liposomes or albumin nanoparticles, the obtained particles exhibit high hemocompatibility and negligible immunogenicity. Furthermore, these materials also display attentional abilities in the aspects of light absorption and free radical scavenging. It is found that HMP and HNP can prevent skin from UV-induced damage and relieve symptoms of cataract in vitro. Besides, both HMP and HNP show satisfactory photothermal conversion ability. By using microcomputed tomography and intravital fluorescence microscopy, it is found that warfarin-loaded HMP can rescue mice from vein thrombosis. In another aspect, HNP modified with tumor targeted aptamers exhibit dramatic antineoplastic effect, and suppress 96.8% of tumor growth in vivo. Thus, the multifaceted materials described here might provide a new tool for addressing biomedical challenges.

Normalizing Tumor Microenvironment Based on Photosynthetic Abiotic/Biotic Nanoparticles

Tumor hypoxia has attained the status of a core hallmark of cancer that globally affects the entire tumor phenotype. Reversing tumor hypoxia might offer alternative therapeutic opportunities for current anticancer therapies. In this research, a photosynthetic leaf-inspired abiotic/biotic nano-thylakoid (PLANT) system was designed by fusing the thylakoid membrane with synthetic nanoparticles for efficient O₂ generation in vivo. Under 660 nm laser irradiation, the PLANT system exhibited intracellular O₂ generation and the anaerobic respiration of the multicellular tumor spheroid was suppressed by PLANT as well. In vivo, it was found that PLANT could not only normalize the entire metabolic network but also adjust the abnormal structure and function of the tumor vasculature. It was demonstrated that PLANT could significantly enhance the efficacy of phototherapy or antiangiogenesis therapy. This facile approach for normalizing the tumor microenvironment will find great potential in tumor therapy.

[Association between obesity and DNA methylation among the 7-16 year-old twins]

Objective: On whole-genome scale, we tried to explore the correlation between obesity-related traits and DNA methylation sites, based on discordant monozygotic twin pairs. Methods: A total of 90 pairs of 6-17 year-old twins were recruited in Chaoyang district, Yanqing district and Fangshan district in Beijing in 2016. Information on twins was gathered through a self-designed questionnaire and results: from physical examination, including height, weight and waist circumference of the subjects under study. DNA methylation detection was chosen on the Illumina Human Methylation EPIC BeadChip. R 3.3.1 language was used to read the DNA methylation signal under quality control on samples and probes. Ebayes function of empirical Bayes paired moderated t-test was used to identify the differential methylated CpG sites (DMCs). VarFit function of empirical Bayes paired moderated Levene test was used to identify the differentially variables CpG sits (DVCs) in obese and normal groups. Results According to the obesity discordance criteria, we collected 23 pairs of twins (age range 7 to 16 years), including 12 male pairs. A total of 817 471 qualified CpG loci were included in the genome-wide correlation analysis. According to the significance level of FDR set as <0.05, no positive sites would meet this standard. When DMC CpG site cg05684382, with the smallest P value (1.26E-06) as on chromosome 12, the DVC CpG site cg26188191 with the smallest P value (6.44E-06) appeared in CMIP gene on chromosome 16. Conclusions: In this study, we analyzed the genome-wide DNA methylation and its correlation with obesity traits. After multiple testing corrections, no positive sites were found to have associated with obesity. However, results from the correlation analysis demonstrated sites cg05684382 (chr: 12) and cg26188191 (chr: 16) might have played a role in the development of obesity. This study provides a methodologic reference for the studies on discordance twins related problems.

[Efficacy and safety of mycophenolate mofetil in treating neuromyelitis optica spectrum disorder: a multicenter, prospective, self-control study in Guangzhou City]

Objective: To evaluate the efficacy and safety of mycophenolate mofetil (MMF) in neuromyelitis optica spectrum disorder (NMOSD). Method: From September 2014 to February 2017, NMOSD patients with seropositive aquaporin4-IgG was enrolled through a multicenter, prospective study, and the annual recurrence rate (ARR), Expanded Disability Status Scale (EDSS) and MMF-related side effects before and after MMF treatment were compared. Results: Ninety patients were enrolled in the study. After being treated for a median of 12 months (1-30 months), the median ARR decreased from 1.1 pre-MMF to 0 post-MMF (P<0.001), and the median EDSS score decreased from 4.0 pre-MMF to 3.0 post-MMF (P<0.001). The EDSS score reduced significantly after 90 days' treatment (P<0.05). The main adverse events included the deranged liver enzymes (19%, 17/90), respiratory infection (11%, 10/90), urinary tract infection (6%, 5/90), varicella-zoster infection (6%, 5/90), anemia (6%, 5/90), leucopenia (6%, 5/90), diarrhea (2%, 2/90), hair loss (1%, 1/90); 11% (10/90) patients experienced severe adverse events, and 6% (5/90) patients discontinued MMF. Conclusions: MMF could significantly reduce the ARR and EDSS score of NMOSD. However, awareness on side effects should be raised.

Double-Targeting Explosible Nanofirework for Tumor Ignition to Guide Tumor-Depth Photothermal Therapy

This study reports a double-targeting "nanofirework" for tumor-ignited imaging to guide effective tumor-depth photothermal therapy (PTT). Typically, ≈30 nm upconversion nanoparticles (UCNP) are enveloped with a hybrid corona composed of ≈4 nm CuS tethered hyaluronic acid (CuS-HA). The HA corona provides active tumor-targeted functionality together with excellent stability and improved biocompatibility. The dimension of UCNP@CuS-HA is specifically set within the optimal size window for passive tumor-targeting effect, demonstrating significant contributions to both the in vivo prolonged circulation duration and the enhanced size-dependent tumor accumulation compared with ultrasmall CuS nanoparticles. The tumors featuring hyaluronidase (HAase) overexpression could induce the escape of CuS away from UCNP@CuS-HA due to HAase-catalyzed HA degradation, in turn activating the recovery of initially CuS-quenched luminescence of UCNP and also driving the tumor-depth infiltration of ultrasmall CuS for effective PTT. This in vivo transition has proven to be highly dependent on tumor occurrence like a tumor-ignited explosible firework. Together with the double-targeting functionality, the pathology-selective tumor ignition permits precise tumor detection and imaging-guided spatiotemporal control over PTT operation, leading to complete tumor ablation under near infrared (NIR) irradiation. This study offers a new paradigm of utilizing pathological characteristics to design nanotheranostics for precise detection and personalized therapy of tumors.

Optically-controlled bacterial metabolite for cancer therapy

Bacteria preferentially accumulating in tumor microenvironments can be utilized as natural vehicles for tumor targeting. However, neither current chemical nor genetic approaches alone can fully satisfy the requirements on both stability and high efficiency. Here, we propose a strategy of "charging" bacteria with a nano-photocatalyst to strengthen their metabolic activities. Carbon nitride (C3N4) is combined with Escherichia coli (E. coli) carrying nitric oxide (NO) generation enzymes for photo-controlled bacterial metabolite therapy (PMT). Under light irradiation, photoelectrons produced by C3N4 can be transferred to E. coli to promote the enzymatic reduction of endogenous NO3- to cytotoxic NO with a 37-fold increase. In a mouse model, C3N4 loaded bacteria are perfectly accumulated throughout the tumor and the PMT treatment results in around 80% inhibition of tumor growth. Thus, synthetic materials-remodeled microorganism may be used to regulate focal microenvironments and increase therapeutic efficiency.

[Assessment of Height Prediction Model Based on SNPs Loci]

OBJECTIVES

To establish a height prediction model of Chinese Han male based on the reported 547 height-associated single nucleotide polymorphisms （SNPs） loci in Europeans, and assess its accuracy for height estimation.

METHODS

The DNA typing was analyzed in 59 Han male samples of Shandong province by Affymetrix SNP Array 6.0 chip and HiSeq 4000 sequencing platform. Prediction model was established using 547 height-associated SNPs loci as predictors and weight allele sums （WAS） as computing method. The accuracy of height prediction model was analysed using receiver operating characteristic （ROC） curve and area under curve （AUC）.

RESULTS

There was no height-associated SNPs locus was found by genome-wide association studies. In present study, height prediction model was established by WAS and obtained an AUC of 0.67 （95% CI: 0.53-0.90）.

CONCLUSIONS

It has reference value for predicting the height of Han male in Shandong province by WAS model based on 547 SNPs loci, while it is still necessary to further promote the accuracy of the prediction model by screening more height-associated SNPs loci with population heterogeneity.

Enhanced Immunotherapy Based on Photodynamic Therapy for Both Primary and Lung Metastasis Tumor Eradication

Metastasis and recurrence are two unavoidable and intractable problems in cancer therapy, despite various robust therapeutic approaches. Currently, it seems that immunotherapy is an effective approach to solve these problems, but the high heterogeneity of tumor tissue, inefficient presentation of tumor antigen, and deficient targeting ability of therapy usually blunt the efficacy of immunotherapy and hinder its clinical application. Herein, an approach based on combining photodynamic and immunological therapy was designed and developed. We synthesized a chimeric peptide, PpIX-1MT, which integrates photosensitizer PpIX with immune checkpoint inhibitor 1MT via a caspase-responsive peptide sequence, Asp-Glu-Val-Asp (DEVD), to realize a cascaded synergistic effect. The PpIX-1MT peptide could form nanoparticles in PBS and accumulate in tumor areas via the enhanced penetration retention effect. Upon 630 nm light irradiation, the PpIX-1MT nanoparticles produced reactive oxygen species, induced apoptosis of cancer cells, and thus facilitated the expression of caspase-3 and the production of tumor antigens, which could trigger an intense immune response. The subsequently released 1MT upon caspase-3 cleavage could further strengthen the immune system and help to activate CD8⁺ T cells effectively. This cascaded synergistic effect could inhibit both primary and lung metastasis tumor effectively, which may provide the solution for solving tumor recurrence and metastasis clinically.

A metal-semiconductor nanocomposite as an efficient oxygen-independent photosensitizer for photodynamic tumor therapy

Photodynamic therapy (PDT) is regarded as one of the most promising cancer treatments, and oxygen-independent photosensitizers have been intensively explored for advancing the development of PDT. Here, we reported on a superior hybrid nanocomposite (HNC) consisting of a metal (Au deposition) and a semiconductor (CdSe-seeded/CdS nanorods) as a photosensitizer. Under visible light, the photogenerated holes were three-dimensionally confined to the CdSe quantum dots and the delocalized electrons were transferred to the Au tips, which provided hydrogen and oxygen evolution sites for water splitting to generate reactive oxygen species (ROS) with no need for oxygen participation. Compared with semiconductors without deposited metal (i.e. raw CdSe-seeded/CdS nanorods (NRs)) under a normoxic or hypoxic environment, the HNCs exhibited substantially enhanced light-triggered ROS generation in vitro. After being modified with an Arg-Gly-Asp (RGD) peptide sequence, the nanocomposite was deemed as a tumor-targeting, long-lived and oxygen-independent photosensitizer with promoted PDT efficiency for in vivo anti-tumor therapy. This oxygen-independent nanocomposite successfully overcame the hypoxia-related PDT resistance by water splitting, which opened a window to develop conventional semiconductors as photosensitizers for effective PDT.

Photocatalyzing CO2 to CO for Enhanced Cancer Therapy

Continuous exposure to carbon monoxide (CO) can sensitize cancer cells to chemotherapy while protect normal cells from apoptosis. The Janus face of CO thus provides an ideal strategy for cancer therapy. Here, a photocatalytic nanomaterial (HisAgCCN) is introduced to transform endogenous CO₂ to CO for improving cancer therapy in vivo. The CO production rate of HisAgCCN reaches to 65 µmol h^-1 g_mat^-1 , which can significantly increase the cytotoxicity of anticancer drug (doxorubicin, DOX) by 70%. Interestingly, this study finds that HisAgCCN can enhance mitochondria biogenesis and aggravate oxidative stress in cancer cells, whereas protect normal cells from chemotherapy-induced apoptosis as well. Proteomics and metabolomics studies reveal that HisAgCCN can enhance mitochondria biogenesis and aggravate oxidative stress in cancer cells specifically. In vivo studies indicate that HisAgCCN/DOX combination therapy presents a synergetic tumor inhibition, which might provide a new direction for clinical cancer therapy.

Cancer Cell Membrane Camouflaged Cascade Bioreactor for Cancer Targeted Starvation and Photodynamic Therapy

Selectively cuting off the nutrient supply and the metabolism pathways of cancer cells would be a promising approach to improve the efficiency of cancer treatment. Here, a cancer targeted cascade bioreactor (designated as mCGP) was constructed for synergistic starvation and photodynamic therapy (PDT) by embedding glucose oxidase (GOx) and catalase in the cancer cell membrane-camouflaged porphyrin metal-organic framework (MOF) of PCN-224 (PCN stands for porous coordination network). Due to biomimetic surface functionalization, the immune escape and homotypic targeting behaviors of mCGP would dramatically enhance its cancer targeting and retention abilities. Once internalized by cancer cells, mCGP was found to promote microenvironmental oxygenation by catalyzing the endogenous hydrogen peroxide (H₂O₂) to produce oxygen (O₂), which would subsequently accelerate the decomposition of intracellular glucose and enhance the production of cytotoxic singlet oxygen (¹O₂) under light irradiation. Consequently, mCGP displayed amplified synergistic therapeutic effects of long-term cancer starvation therapy and robust PDT, which would efficiently inhibit the cancer growth after a single administration. This cascade bioreactor would further facilitate the development of complementary modes for spatiotemporally controlled cancer treatment.

[Analysis of 118 cases of benign paroxysmal positional vertigo after trauma]

Objective:The aim of this study is to retrospective analysis the clinic features of 118 cases of benign paroxysmal positional vertigo after trauma. Method:Analyzes clinic features of injury in 118 cases of benign paroxysmal positional vertigo after trauma, and classified and localized the craniocerebral trauma. The 118 cases were tested with different positioning tests in the sequence of Dix hallpike test and rolling test. Then, proper otolith manual reduction was given. Result:In 118 cases of BPPV after trauma including 35 cases of skull fracture, 6 cases of concussion, 17 cases of scalp hematoma, 28 cases of scalp laceration, 14 cases of mild brain contusion and 18 cases of head combined injury. The distributions of head injury were 57 at front temporal, 24 at top, 22 at occipital and 15 at maxillofacial region. The latency of BPPV after head injury varies from 1day to 1month. The incidence of 3-7 day after head injury was the highest, followed by 7-14 days, 0-3 days, and the lowest incidence rate of 14 day to 1 month. Canal type 118 BPPV patients after head injury accounting for up to 57.6% of the horizontal semicircular canal accounted for 33.1%, mixed 9.3%. Conclusion:The patients with front temporal trauma and skull fracture were prone to have BPPV. The peak incidence of BPPV was 3-14 days after head injury. The most common type of BPPV was PC BPPV, and the HC BPPV was the second type. A good curative effect can be manipulative reduction after trauma BPPV..

Switching Apoptosis to Ferroptosis: Metal-Organic Network for High-Efficiency Anticancer Therapy

Discovering advanced materials for regulating cell death is of great importance in the development of anticancer therapy. Herein, by harnessing the recently discovered oxidative stress regulation ability of p53 and the Fenton reaction inducing capability of metal-organic network (MON), MON encapsulated with p53 plasmid (MON-p53) was designed to eradicate cancer cells via ferroptosis/apoptosis hybrid pathway. After confirming the detailed mechanism of MON-p53 in evoking ferroptosis, we further discovered that MON-p53 mediated a "bystander effect" to further sensitize cancer cells toward the MON-p53 induced ferroptosis. A 75-day anticancer experiment indicated that MON-p53 treatment not only suppressed the tumor growth but also prolonged the life-span of tumor bearing mice. Owing to its ability to promote intracellular oxidative stress, MON-p53 decreased the blood metastasis, lung metastasis, and liver metastasis. As a consequence, discovering methods to induce cell ferroptosis would provide a new insight in designing anticancer materials.

Carbon-Dot-Decorated Carbon Nitride Nanoparticles for Enhanced Photodynamic Therapy against Hypoxic Tumor via Water Splitting

Hypoxia, a typical feature of solid tumors, remarkably restricts the efficiency of photodynamic therapy (PDT). Here, a carbon nitride (C3N4)-based multifunctional nanocomposite (PCCN) for light-driven water splitting was used to solve this problem. Carbon dots were first doped with C3N4 to enhance its red region absorption because red light could be used to trigger the in vivo water splitting process. Then, a polymer containing a protoporphyrin photosensitizer, a polyethylene glycol segment, and a targeting Arg-Gly-Asp motif was synthesized and introduced to carbon-dot-doped C3N4 nanoparticles. In vitro study showed that PCCN, thus obtained, could increase the intracellular O2 concentration and improve the reactive oxygen species generation in both hypoxic and normoxic environments upon light irradiation. Cell viability assay demonstrated that PCCN fully reversed the hypoxia-triggered PDT resistance, presenting a satisfactory growth inhibition of cancer cells in an O2 concentration of 1%. In vivo experiments also indicated that PCCN had superior ability to overcome tumor hypoxia. The use of water splitting materials exhibited great potential to improve the intratumoral oxygen level and ultimately reverse the hypoxia-triggered PDT resistance and tumor metastasis.

Investigations of high order plasmonic resonance features of the nano hyper ring

A novel silver hyper ring and its complex nanostructures are designed and its plasmonic properties are investigated numerically. It is found that these hyper ring structures have relative stable optical features. The absorption cross section of the structure changes slightly when the direction and polarization of incident light is adjusting. For the complex structure, the position of each resonance peak does not present obvious change when the relative position of the inner hyper ring and outside larger ring changes. The result of the investigation has great significance for the production of practical nanostructures and the improvement of possible applications.

[Isolation and biological characteristics on Yersinia pestis phage YP060]

OBJECTIVE

To isolate and identify the characteristics of Yersinia pestis phage YP060 from mice nests in Yunnan plague focus.

METHODS

Phage YP060 was isolated from Yunnan plague focus by double-layer agar plate method with attenuated vaccine Yersinia pestis strain EV76 as the host bacterium. Phage particle was observed under the electron microscope while biological properties of phage YP060 including lytic capacity, host spectrum, optimal multiplicity of infection (MOI), one-step growth curve, sensitivity to temperature, pH, ultraviolet ray and chloroform etc. were identified.

RESULTS

The particles of phage YP060 presented tadpoles-like features, with optimal multiplicity of infection as 0.1. Latent period and burst period appeared as 50 min and 80 min, respectively. The phage endured the temperature between 30-50 ℃, and it contained a stronger lysis activities in a range of pH 5 to 10. Phage YP060 was sensitive to ultraviolet rays but insensitive to chloroform while presented special lysic ability to Yersinia pestis.

CONCLUSION

Yersinia pestis phage YP060 was isolated for the first time from mice nests in plague natural focus in China. Our findings related to narrow host spectrum and stronger lysis activities.