Natural Compound-Rhein and PROTACs Unleash Potent VEGFR-2 Degraders.

VEGFR-2 is a prominent therapeutic target in antitumor drug research to block tumor angiogenesis. This study focused on the synthesis and optimization of PROTACs based on the natural product rhein, resulting in the successful synthesis of 15 distinct molecules. In A549 cells, D9 exhibited remarkable antitumor efficacy with an IC50 of 5.88±0.50 µM, which was 15-fold higher compared to rhein (IC50=88.45±2.77 µM). An in-depth study of the effect of D9 on the degradation of VEGFR-2 revealed that D9 was able to induce the degradation of VEGFR-2 in A549 cells in a time-dependent manner. The observed effect was reversible, contingent upon the proteasome and ubiquitination system, and demonstrably linked to CRBN. Further experiments revealed that D9 induced apoptosis in A549 cells and led to cell cycle arrest in the G1 phase. Molecular docking simulations validated the binding mode of D9 to VEGFR, establishing the potential of D9 to bind to VEGFR-2 in its natural state. In summary, this study confirms the feasibility of natural product-bound PROTAC technology for the development of a new generation of VEGFR-2 degraders, offering a novel trajectory for the future development of pharmacological agents targeting VEGFR-2.

Transarterial chemoembolization (TACE) plus tyrosine kinase inhibitors versus TACE in patients with hepatocellular carcinoma: a systematic review and meta-analysis.

PURPOSE: Transarterial chemoembolization (TACE) with tyrosine kinase inhibitors (TKIs) has been increasingly used to treat unresectable hepatocellular carcinoma (uHCC). However, the superiority of combination therapy to TACE monotherapy remains controversial. Therefore, here we performed a meta-analysis to evaluate the efficacy and safety of TACE plus TKIs in patients with uHCC. METHODS: We searched four databases for eligible studies. The primary outcome was time to progression (TTP), while the secondary outcomes were overall survival (OS), tumor response rates, and adverse events (AEs). Pooled hazard ratios (HRs) with 95% confidence intervals (95% CIs) were collected for TTP and OS, and the data were analyzed using random-effects meta-analysis models in STATA software. OR and 95% CIs were used to estimate dichotomous variables (complete remission[CR], partial remission[PR], stable disease[SD], progressive disease[PD], objective response rate[ORR], disease control rate[DCR], and AEs) using RStudio's random-effects model. Quality assessments were performed using the Newcastle-Ottawa scale (NOS) for observational studies and the Cochrane risk of bias tool for randomized controlled trials (RCTs). RESULTS: The meta-analysis included 30 studies (9 RCTs, 21 observational studies) with 8246 patients. We judged the risk of bias as low in 44.4% (4/9) of the RCTs and high in 55.6% (5/9) of the RCTs. All observational studies were considered of high quality, with a NOS score of at least 6. Compared with TACE alone or TACE plus placebo, TACE combined with TKIs was superior in prolonging TTP (combined HR 0.72, 95% CI 0.65-0.80), OS (combined HR 0.57, 95% CI 0.49-0.67), and objective response rate (OR 2.13, 95% CI 1.23-3.67) in patients with uHCC. However, TACE plus TKIs caused a higher incidence of AEs, especially hand-foot skin reactions (OR 87.17%, 95%CI 42.88-177.23), diarrhea (OR 18.13%, 95%CI 9.32-35.27), and hypertension (OR 12.24%, 95%CI 5.89-25.42). CONCLUSIONS: Our meta-analysis found that TACE plus TKIs may be beneficial for patients with uHCC in terms of TTP, OS, and tumor response rates. However, combination therapy is also associated with a significantly increased risk of adverse reactions. Therefore, we must evaluate the clinical benefits and risks of combination therapy. Further well-designed RCTs are needed to confirm our findings. TRIAL REGISTRATION: PROSPERO registration number: CRD42022298003.

Azoreductase-Responsive Nanoprobe for Hypoxia-Induced Mitophagy Imaging.

Mitophagy, as a crucial metabolic process, plays an essential role in maintaining cellular and tissue homeostasis. Various stresses especially hypoxia could improve intracellular reactive oxygen species (ROS) level to induce mitophagy. However, high-specific fluorescence imaging of mitophagy in living cells under hypoxia is still a challenge. Based on this, we report an azoreductase-responsive nanoprobe (termed Micelle@Mito-rHP@TATp, MCM@TATp) by encapsulating cationic spiropyrane derivative (Mito-rHP) to realize specific imaging of mitophagy in living cells under hypoxia. An azoreductase-responsive amphiphilic polymer, 1,2-distearoyl- sn-glycero-3-phosphoethanolamine-azo- N-[maleimide(polyethylene glycol-2000) (Mal-PEG2000-Azo-DSPE), was first self-assembled into a micelle in aqueous solution. Meanwhile, the synthetic Mito-rHP encapsulated into this formed micelle to construct MCM. By modifying the surface of MCM with cell-penetrating peptide (TATp) to form MCM@TATp, the nanoprobe could avoid endolysosomal trapping. Under hypoxic conditions, the azobenzene moiety-contained MCM@TATp would be disrupted by the highly expressed azoreductase, then the encapsulated Mito-rHP would be released. Since Mito-rHP is a mitochondria-targeted and pH-sensitive probe, thus it could target into mitochondria and displayed a desirable "off-on" fluorescence response to mitophagy during which mitochondria were regarded to undergo acidification. The results indicated that the MCM@TATp in our design could image mitophagy under hypoxia in high-specificity. As further application, we have also demonstrated that this MCM@TATp can perform well to realize mitophagy imaging under the photodynamic therapy (PDT) which can induce hypoxia in treatment of cancer. We expect this new strategy would be a powerful tool for hypoxia-related fundamental and clinical research.

Azoreductase and Target Simultaneously Activated Fluorescent Monitoring for Cytochrome c Release under Hypoxia.

Hypoxia-induced cell apoptosis is closely related to degenerative diseases, autoimmune disorders, and tumor disease. In the process of apoptosis, the release of cytochrome c (Cyt c) is deemed to be a critical factor of the intrinsic pathway. Strategies for tracking Cyt c release in living cells based on the subcellular localization have been proposed recently. However, they are inherently lack of specificity for distinguishing the release of Cyt c in apoptotic process induced by hypoxia from other stimulus. In this paper, an azoreductase and target simultaneously activated fluorescent aptameric nanosensor integrating gold nanoparticles (AuNPs) and Cyt c-targeted aptamer-consisted double-stranded DNA hybridization complex (DSDHC) was proposed. It is worth noting that the employment of azobenzene moiety labeled on the DSDHC first ensured the aptameric nanosensor could be conjugated to the surface of AuNPs and then specifically reduced by hypoxia-related azoreductase. Upon Cyt c released from mitochondrion under hypoxia, the competitive displacement of Cyt c subsequently activated the fluorescence of the aptameric nanosensor and the fluorescence enhancement depended principally on the content of Cyt c release. Inspired by this, a new strategy for quantitative analysis and in situ imaging of Cyt c under hypoxic condition was proposed. The high spatial resolution monitoring of the dynamics of Cyt c release under hypoxia will offer a potentially rich opportunity to understand the apoptotic mechanism under hypoxic conditions, thus further facilitating risk assessment and risk reduction for hypoxic environments.

Noninvasive and Highly Selective Monitoring of Intracellular Glucose via a Two-Step Recognition-Based Nanokit.

Accurate determination of intracellular glucose is very important for exploring its chemical and biological functions in metabolism events of living cells. In this paper, we developed a new noninvasive and highly selective nanokit for intracellular glucose monitoring via two-step recognition. The liposome-based nanokit coencapsulated the aptamer-functionalized gold nanoparticles (AuNPs) and the Shinkai's receptor together. When the proposed nanokit was transfected into living cells, the Shinkai's receptor could recognize glucose first and then changed its conformation to endow aptamers with binding and sensing properties which were not readily accessible otherwise. Then, the binary complexes formed by the intracellular glucose and the Shinkai's receptor can in situ displace the complementary oligonucleotide of the aptamer on the surface of AuNPs. The fluorophore-labeled aptamer was away from the AuNPs, and the fluorescent state switched from "off" to "on". Through the secondary identification of aptamer, the selectivity of the Shinkai's receptor could be greatly improved while the intracellular glucose level was assessed by fluorescence signal recovery of aptamer. In the follow-up application, the approach exhibits excellent selectivity and is noninvasive for intracellular glucose monitoring under normoxia and hypoxia. To the best of our knowledge, this is the first time that the advantages of organic receptors and nucleic acids have been combined and highly selective monitoring of intracellular glucose has been realized via two-step recognition. We expect it to open up new possibilities to integrate devices for diagnosis of various metabolic diseases and insulin delivery.

On the Relationship between MMA Levels in Blood Products and Donor Sex, Age, and Donation Frequency.

As the aging process accelerates, the age structure of blood donors turns to older and even aged groups. Methylmalonic acid (MMA), a byproduct of propionate metabolism, may be upregulated in the serum of older adults. As a mediator of chronic disease and tumor progression, the MMA content in blood products has become the focus of research. Absolute concentrations of MMA in blood products were determined based on the liquid chromatography-tandem mass spectrometry, so as to analyze how they were affected by donors' age, sex, and frequency of blood donation. The MMA content in leukocyte-depleted suspended red blood cell (lds-RBC) was significantly higher than that in fresh plasma (p<0.0001). The MMA content among five age groups showed no difference in either fresh plasma or lds-RBCs. The MMA content in fresh plasma was similar in the parameters of the sex, whereas that in lds-RBCs was higher in males than that in females (p=0.035). There were no significant differences in MMA content when it comes to different frequencies of blood donors in either fresh plasma or lds-RBCs. Additionally, there was no significant difference or clear trend in the rate of elevated plasma MMA levels among different sexes, age groups, and blood donation frequency groups. MMA in the blood products from donors in China does not compromise the safety of blood transfusions for cancer patients. Nevertheless, there is a need to focus on MMA levels in Chinese and to develop race-specific and age-specific normal reference ranges.

Hippo pathway-independent restriction of TAZ and YAP by angiomotin.

The Hippo pathway restricts the activity of transcriptional co-activators TAZ and YAP by phosphorylating them for cytoplasmic sequestration or degradation. In this report, we describe an independent mechanism for the cell to restrict the activity of TAZ and YAP through interaction with angiomotin (Amot) and angiomotin-like 1 (AmotL1). Amot and AmotL1 were robustly co-immunoprecipitated with FLAG-tagged TAZ, and their interaction is dependent on the WW domain of TAZ and the PPXY motif in the N terminus of Amot. Amot and AmotL1 also interact with YAP via the first WW domain of YAP. Overexpression of Amot and AmotL1 caused cytoplasmic retention of TAZ and suppressed its transcriptional outcome such as the expression of CTGF and Cyr61. Hippo refractory TAZ mutant (S89A) is also negatively regulated by Amot and AmotL1. HEK293 cells express the highest level of Amot and AmotL1 among nine cell lines examined, and silencing the expression of endogenous Amot increased the expression of CTGF and Cyr61 either at basal levels or upon overexpression of exogenous S89A. These results reveal a novel mechanism to restrict the activity of TAZ and YAP through physical interaction with Amot and AmotL1.

[Changes in the physical growth of children aged 3 to 6 years in urban areas of Lanzhou from 2001 to 2010].

OBJECTIVE: To study changes in the physical growth of preschool children aged 3 to 6 yeas in urban areas of Lanzhou from 2001 to 2010. METHODS: Stratified, randomized, cluster sampling was used to collect physical examination data on children from 35 private and public kindergartens located in different urban areas of Lanzhou in 2001, 2006, and 2010. Changes in physical growth were analyzed using body height, body weight and body mass index (BMI) as main indices. Growth retardation, underweight, overweight, emaciation and obesity were screened out using height for age (HAZ), weight for age (WAZ), and weight for height (WHZ) and changes from 2001 to 2010 were analyzed. RESULTS: Body height, body weight and BMI increased from 2001 to 2010 in children at different ages (P<0.05). Body height and weight increased with age, while BMI decreased with age. Mean values of HAZ, WAZ, and WHZ increased over time, showing that prevalence rates of underweight, growth retardation, and emaciation decreased from 2001 to 2010 while those of overweight and obesity increased. CONCLUSIONS: Changes in the physical growth of preschool children in urban areas of Lanzhou from 2001 to 2010 were obvious, with increases in body height and body weight. However, problems such as overweight and obesity emerged. In response, while malnutrition is being solved, attention should be paid to over-nutrition that has an adverse effect on physical growth.

Relationship Between Mortality and Seizures After Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis.

Background: The relationship between mortality and seizures after intracerebral hemorrhage (ICH) has not yet been understood until now. A meta-analysis was performed to assess the effect of post-ICH seizures on mortality among patients with ICH. Methods: PubMed and Embase were searched from the establishment of the databases to December 2021 to identify literature that evaluated the relationship between post-ICH seizures and mortality in ICH. Crude odds ratios and adjusted odds ratios with a 95% confidence interval (CI) were pooled using a random-effects model. Results: Thirteen studies involving 245,908 participants were eventually included for analysis. The pooled estimate suggested that post-ICH seizures were not associated with significantly increased mortality in patients with ICH (crude odds ratios 1.35, 95% CI: 0.91-2; adjusted adds ratios 1.22, 95% CI: 0.78-1.88). However, the relationship was not consistent in subgroup analysis or robust in a sensitivity analysis. Conclusions: This meta-analysis proved that post-ICH seizures were not associated with significantly increased mortality in patients with ICH. However, this result could be influenced by confounding factors, so more high-quality research is needed.

The Hippo pathway in biological control and cancer development.

The Hippo pathway is an evolutionally conserved protein kinase cascade involved in regulating organ size in vivo and cell contact inhibition in vitro by governing cell proliferation and apoptosis. Deregulation of the Hippo pathway is linked to cancer development. Its first core kinase Warts was identified in Drosophila more than 15 years ago, but it gained much attention when other core components of the pathway were identified 8 years later. Major discoveries of the pathway were made during past several years. The core kinase components Hippo, Salvador, Warts, and Mats in the fly and Mst1/2, WW45, Lats1/2, and Mob1 in mammals phosphorylate and inactivate downstream transcriptional co-activators Yorkie in the fly, Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) in mammals, respectively. Phosphorylated Yorkie, YAP, and TAZ are sequestered in the cytoplasm by interaction with 14-3-3 proteins. Here we review recent progresses of this pathway by focusing on how these proteins communicate with each other and how loss of regulation results in cancers.

Effects of water and nitrogen coupling on the photosynthetic characteristics, yield, and quality of Isatis indigotica.

Isatis indigotica is a commercial medicinal crop that is widely cultivated with high water and nutrient application, in the arid areas of northwest China. Rational irrigation and nitrogen application are key factors for successful crop management. The objective of this study was to determine the effect of water and nitrogen coupling on the photosynthetic characteristics, yield, and quality of Isatis indigotica produced in northwestern China. Field trials were conducted for 2 consecutive years at an irrigation test station. Data on photosynthetic parameters, yield, and quality were collected from individual Isatis indigotica for each treatment during 2018-2019. The application of nitrogen significantly increased photosynthetic rates and yield under the same irrigation conditions. However, the yields were reduced in the excess water treatments (W3N1 and W3N2) and in the excess nitrogen treatments (W1N3, W2N3, and W3N3) in contrast to the optimum W2N2 treatment. Moreover, the quality indicators of the W2N2 treatment decreased compared with CK, which was due to water stress and more photoassimilates being available to the roots, but the effective quality index value could be effectively improved by greatly increasing the yield.

Meadow degradation increases spatial turnover rates of the fungal community through both niche selection and dispersal limitation.

The alpine meadow ecosystem, as the main ecosystem of the Qinghai-Tibet Plateau, has been heavily degraded over the past several decades due to overgrazing and climate change. Although soil microorganisms play key roles in the stability and succession of grassland ecosystems, their response to grassland degradation has not been investigated at spatial scale. Here, we systematically analyzed the spatial turnover rates of soil prokaryotic and fungal communities in degraded and undegraded meadows through distance-decay relationship (DDR) and species area relationship (SAR), as well as the community assembly mechanisms behind them. Although the composition and structure of both fungal and prokaryotic communities showed significant changes between undegraded and degraded meadows, steeper spatial turnover rates were only observed in fungi (Degraded Alpine Meadow ß = 0.0142, Undegraded Alpine Meadow ß = 0.0077, P < 0.05). Mantel tests indicated that edaphic variables and vegetation factors showed significant correlations to the ß diversity of fungal community only in degraded meadow, suggesting soil and vegetation heterogeneity both contributed to the variation of fungal community in that system. Correspondingly, a novel phylogenetic null model analysis demonstrated that environmental selection was enhanced in the fungal community assembly process during meadow degradation. Interestingly, dispersal limitation was also enhanced for the fungal community in the degraded meadow, and its relative contribution to other assembly process (i.e. selection and drift) showed a significant linear increase with spatial distance, suggesting that dispersal limitation played a greater role as distance increased. Our findings indicated the spatial scaling of the fungal community is altered during meadow degradation by both niche selection and dispersal limitation. This study provides a new perspective for the assessment of soil microbial responses to vegetation changes in alpine areas.

Danhong injection for the treatment of early diabetic nephropathy: A protocol of systematic review and meta-analysis.

BACKGROUND: Diabetic nephropathy (DN) is the one that of the most common complications of diabetes mellitus (DM). Diabetic patients will experience a high mortality rate when DN progress to end-stage. So, it is extremely important to early treat DN. Although several interventions have been used to treat DN, a conclusive finding has not already been achieved. As one of the most common Chinese medicines, danhong injection (DHI) which has been shown to have various functions has also been prescribed to be as the alternative treatment option. However, no systematic review and meta-analysis has been conducted to objectively and comprehensively investigate its effectiveness and safety. Thus, we designed the current systematic review and meta-analysis to answer whether DHI can be preferably used to timely treat DN. METHODS: We will perform a systematic search to capture any potentially eligible studies in several electronic databases including PubMed, Cochrane library, Embase, China National Knowledgement Infrastructure (CNKI), Wanfang database, and Chinese sci-tech periodical full-text database (VIP) from their inception to August 31, 2020. We will assign 2 independent reviewers to select eligible studies, and assess the quality of included studies with Cochrane risk of bias assessment tool. We will perform all statistical analyses using RevMan 5.3 software. ETHICS AND DISSEMINATION: We will submit our findings to be taken into consideration for publication in a peer-reviewed academic journal. Meanwhile, we will also communicate our findings in important conferences. PROTOCOL REGISTRY: The protocol of this systematic review and meta-analysis has been registered at the International Plateform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) platform (https://inplasy.com/inplasy-2020-9-0005/, registry number: INPLASY202090005) and this protocol was funded through a protocol registry.

Whole plastid genome of Anemone taipaiensis (Ranunculaceae), an endemic herb plant in China.

Anemone taipaiensis W. T. Wang is an endemic herb species in Shaanxi province (China). Here, we first characterized its whole plastid genome via pair-end sequencing method. The whole chloroplast genome was 156,659 bp in size, including a large single-copy (LSC) region of 78,439 bp, a small single-copy (SSC) region of 16,178 bp, and two repeat regions (IRs) of 31,021 bp. A total of 135 genes, including 91 protein-coding genes, 36 tRNA, and 8 rRNA genes were identified in A. taipaiensis. The phylogenetic analysis showed that A. taipaiensis have a close relationship with congeneric species A. trullifolia.

Highly selective imaging of lysosomal azoreductase under hypoxia using pH-regulated and target-activated fluorescent nanoprobes.

In this work, we propose a pH-regulated and target-activated fluorescent nanoprobe for highly selective monitoring of lysosomal azoreductase under hypoxia in living cells. We expect it will offer a potentially rich opportunity to understand the physiological processes of lysosomes under hypoxic conditions.

Azoreductase-Responsive Metal-Organic Framework-Based Nanodrug for Enhanced Cancer Therapy via Breaking Hypoxia-induced Chemoresistance.

The insufficient oxygen supply may cause hypoxia in a solid tumor, which can lead to drug resistance and unsatisfactory chemotherapy effect. To address this issue, a new nanodrug has been developed with azoreductase-responsive functional metal-organic frameworks (AMOFs), where chemotherapeutic drugs were encapsulated in the AMOFs and small interfering RNAs (siRNAs) were absorbed on the surface of AMOFs. The siRNA was designed to contain hypoxia-inducible factor (HIF)-1α against RX-0047, which can induce significant downregulation of HIF-1α protein. The azobenzene units within the frameworks of AMOFs could be reduced to amines by the highly expressed azoreductase under the oxygen-deficient environment, which results in azoreductase-responsive release of the encapsulated drugs and siRNAs under the hypoxic condition. Therefore, once the drug-loaded AMOF entered the hypoxic cancer cells, the azoreductase-responsive release of siRNA could decrease the efflux of chemotherapeutic drugs via inhibiting the expressions of HIF-1α, multidrug resistance gene 1, and P-glycoprotein. This nanodrug can thus efficiently break hypoxia-induced chemoresistance and result in high-efficient cancer therapy in hypoxic tumors. As far as we know, this is the first attempt to construct an AMOF-based nanodrug with hypoxic harvesting behaviors. This proof-of-concept research provides a simple strategy for the construction of hypoxic-responsive AMOFs and also offers a unique on-command drug delivery platform, which can effectively break hypoxia-induced chemoresistance.

The complete nucleotide sequence of chloroplast genome of Gentiana apiata (Gentianaceae), an endemic medicinal herb in China.

Gentiana apiata N. E. Brown (Gentianaceae) is a perennial herb plant and only grows in Qinba Mountains in China. Here, we first characterized the complete nucleotide sequence of chloroplast (cp) genome of G. apiata via Illumina next generation sequencing platform. The complete chloroplast genome of G. apiata was 144,274 bp in length, comprising of a large single copy (LSC) region of 77,353 bp, a small single copy (SSC) region of 17,009 bp, and two inverted repeat regions (IRs) of 24,956 bp. The cp genome contains 127 genes, including 82 protein-coding genes, 35 tRNA, eight rRNA genes, and two pseudogenes. Phylogenetic analysis based on 18 cp genome sequences showed that G. apiata closely related to congeneric species.

[Effects of bundled straw mulching on water consumption characteristics and grain yield of winter wheat in rain-fed semiarid region]. / ç§¸ç§†å¸¦çŠ¶è¦†ç›–å¯¹åŠå¹²æ—±é›¨å »åŒºå†¬å°éº¦è€—æ°´ç‰¹å¾å’Œäº§é‡çš„å½±å“.

To explore a new technique of planting wheat with high yield and efficiency by mulching technology in rain-fed semiarid regions in Northwest China, a two-year fixed-site trail was conducted during 2013-2015. There were five mulching modes: (1) three sowing rows by bundled straw mul-ching with alternating 30-cm-wide mulching belt and planting belt (SM1), (2) four sowing rows by bundled straw mulching with alternating 40-cm-wide mulching belt and planting belt with (SM2), (3) five sowing rows by bundled straw mulching with alternating 50-cm-wide mulching belt and planting belt (SM3), (4) whole plastic film mulching with dibbling (PMF), (5) bare field planting without any mulching (CK). We examined the effects of different mulching modes on water consumption, water use efficiency (WUE), and yield of winter wheat in rain-fed region in Northwest China. The results showed that bundled straw mulching significantly increased soil water storage. Soil water storage with bundled straw mulching was remarkably higher than that with the whole plastic mul-ching with SM1＞SM2＞SM3. Soil water storage at 0-200 cm soil layer in flowering period was increased by 15.4%-20.8%,11.2%-14.7%and 10.1%-14.5% respectively over that in the bare field. Bundled straw mulching significantly increased water consumption during the whole growing period while reduced water consumption from sowing and flowering periods. Further, it increased water consumption from flowering to maturity periods and the ratio of water consumption during this period to the total water consumption during the whole growing periods. The results showed that mulching could increase the consumption ratio of deep water storage from the soil layer below 120 cm. Compared with CK, PMF and SM significantly increased grain yield and water use efficiency by 11.9%-19.5%, 26.9%-27.1%, respectively, and increased water use efficiency by 9.8%-13.9%, 18.4%-22.0% respectively. In all, bundled straw mulching could reduce water consumption ratio in the early growing periods, improve moisture condition, increase grain yield and water use efficiency of winter wheat. Therefore, we concluded that bundled straw mulching is an environment-friendly cultivation technology suitable for the winter wheat in semi-arid region of the Loess Plateau in Northwest China.

Hypoxia-triggered gene therapy: a new drug delivery system to utilize photodynamic-induced hypoxia for synergistic cancer therapy.

The therapeutic effects of photodynamic therapy (PDT) are limited by cancer hypoxia because the PDT process is dependent on O2 concentration. Based on this, a new living drug delivery system integrated PDT and hypoxia-triggered gene therapy is proposed, which is made up of three primary constituents: hypoxia-induced cleaved azobenzene (Azo) bridges, HIF-1α-against antisense oligonucleotide (ASO)/G4-constituted double-stranded DNA/RNA hybridization complex (DRHC) and the photosensitizer TMPyP4. During PDT, the continuous consumption of oxygen could remarkably facilitate an intracellular low-oxygen microenvironment. Then, the hypoxia-responsive Azo bridges were reduced by the highly expressed reductases to amines under the oxygen-deficient environment, resulting in a hypoxia-triggered ASO release and providing a synergistic therapy with PDT for suppression of tumor growth. This new drug delivery system opens a new avenue for the design and fabrication of smart drug delivery methods, which can deliver and release drugs according to the specific biological microenvironment in the body.

Quantitative detection of exosomal microRNA extracted from human blood based on surface-enhanced Raman scattering.

Since the nature of the exosomal lipid bilayer can allow miRNAs to be protected from degradation by cellular RNAses in body fluids, exosomal microRNA (miRNA) has become an ideal source of non-invasive biomarkers for the early diagnosis and prognosis. In this paper, a new surface-enhanced Raman scattering (SERS) analysis strategy combining stable SERS reporter element and duplex-specific nuclease (DSN)-assisted signal amplification for quantitative detection of exosomal miRNA extracted from human blood is proposed. Firstly, we prepared SERS signal reporter of Au@R6G@AgAu nanoparticles (R6G attachment on the gold nanoparticles, then encapsulated in AgAu alloy shell nanoparticles named as ARANPs) with an inter small nanogap to generate stable SERS signal. Then, ARANPs and separating substrate of silicon microbead (SiMB) were then covalently attached to the 3'- and 5'- end of capture probe (CP) targeting exosomal miRNA. Upon target miRNA binding, DNA in heteroduplexes could be specifically cleaved by DSN and resulted in the release of ARANPs from the surface of SiMB. Meanwhile, target miRNA remained intact and subsequently involved in the next round of target-recycling amplification. The combination of stable SERS intensity and signal amplification significantly improved the sensitivity of the sensing systems, resulting in detection limits of 5 fM. More importantly, this method also could be used for the detection of exosomal miRNAs extracted from the blood collected from patients of recurrence in non-small-cell lung cancer (NSCLC), with a detection of 5.0µL of sample volume, which has potential for point-of-care testing (POCT) in clinical analysis.