Symmetry-Triggered Tunable Phosphorescence Lifetime of Graphene Quantum Dots in a Solid State.

Studying the phosphorescent mechanisms of carbon nanostructures synthesized by the "bottom-up" approach is key to understanding the structure modulation and the interfacial properties of carbon nanostructures. In this work, the relationships among symmetry of precursors in the "bottom-up" synthesis, structures of products, and phosphorescence lifetimes of graphene quantum dots (GQDs) are studied. The symmetry matching of precursors in the formation of a D6h graphene-like framework is considered the key factor in controlling the separability of sp2 domains in GQDs. As the separability of sp2 domains in GQDs increases, the phosphorescence lifetimes (14.8-125.5 ms) of GQDs in the solid state can be tuned. Machine learning is used to define the degree of disorder (S) of the GQD structure, which quantitatively describes the different space groups of precursors. The negative correlation between S and the oscillator strength of GQDs is uncovered. Therefore, S can be recognized as reflective of oscillator strength in the GQD structure. Finally, based on the correlations found between the structures and phosphorescence lifetimes of GQDs, GQDs with an ultralong phosphorescence lifetime (28.5 s) are obtained. Moreover, GQDs with visible phosphorescence emission (435-618 nm) are synthesized.

Construction of hub transcription factor-microRNAs-messenger RNA regulatory network in recurrent implantation failure.

PURPOSE: Recurrent implantation failure (RIF) affects up to 10% of in vitro fertilization (IVF) patients worldwide. However, the pathogenesis of RIF remains unclear. This study was aimed at identifying hub transcription factors (TFs) of RIF in bioinformatics approaches. METHODS: The GSE111974 (mRNA), GSE71332 (miRNA), and GSE103465 (mRNA) datasets were downloaded from the Gene Expression Omnibus database from human endometrial tissue using R version 4.2.1 and used to identify differentially expressed TFs (DETFs), differentially expressed miRNAs, and differentially expressed genes for RIF, respectively. DETFs were subjected to functional enrichment analysis and the protein-protein interaction network analysis using the Search Tool for the Retrieval of Interacting Genes (version 11.5) database. Hub TFs were identified using the cytoHubb plug-in, after which a hub TF-miRNA-mRNA network was constructed using Cytoscape v3.8.2. RESULTS: Fifty-seven DETFs were identified, in which Gene Ontology analysis revealed to be mainly involved in the regulation of transcription. Kyoto Encyclopedia of Genes and Genomes pathway analysis suggested that DETFs were enriched in transcriptional misregulation in cancer, aldosterone synthesis and secretion, AMPK signaling pathway, and cGMP-PKG signaling pathway. EOMES, NKX2-1, and POU5F1 were identified as hub TFs, and a hub TF-miRNA-mRNA regulatory network was constructed using these three hub TFs, four miRNAs, and four genes. CONCLUSION: Collectively, we identified three promising molecular biomarkers for the diagnosis of RIF, which may further be potential therapeutic targets. This study provides novel insights into the molecular mechanisms underlying RIF. However, further experiments are required to verify these results.

FOXM1 Contributes to Chemotherapy Sensitivity in Cervical Cancer by Regulating TTK.

BACKGROUND: The emergence of chemotherapy resistance usually causes therapeutic failure in advanced cervical cancer. Forkhead box protein M1 (FOXM1) and threonine tyrosine kinase (TTK) are closely associated with cancer drug sensitivity, but the mechanism of FOXM1 on TTK involvement in chemo-treated cervical cancer remains unclear. Here, we aimed to observe the effects of FOXM1 on TTK and on chemotherapy sensitivity in cervical cancer. METHODS: The expressions of FOXM1 and TTK in cervical cancer tissues and para-cancerous tissues were analyzed by immunohistochemistry. SiHa and Hela cells were transfected with human lentivirus-FOXM1, small interfering RNA (siRNA) or pcDNA3.1/FOXM1 to analyze the changes in TTK protein expression. Furthermore, the cells were treated with paclitaxel (8 µM) or cisplatin (10 µM) to analyze the effects of FOXM1 on chemotherapy sensitivity. SiHa cells were used to construct a xenograft model to study the effects of FOXM1 expression in response to paclitaxel treatment. The tumor size and weight were observed. The expressions of Ki-67, FOXM1, and TTK protein in tumor tissues were measured by immunohistochemistry. RESULTS: High expression of FOXM1 and TTK were found in the cervical cancer tissues (p < 0.05). The TTK protein expressions were decreased by FOMX1-siRNA transfection in SiHa and Hela cells (p < 0.01). The cell viability and cell cycle were also suppressed by FOMX1-siRNA transfection (p < 0.01) but enhanced by pcDNA3.1/FOXM1 transfection (p < 0.01). For paclitaxel or cisplatin treatment, the cell viability and cell DNA damage were improved due to the FOXM1 overexpression (p < 0.01). TTK inhibitor significantly suppressed the effects of FOXM1 overexpression (p < 0.01). CONCLUSIONS: FOXM1 regulated TTK and affected the therapeutic efficacy of cisplatin and paclitaxel in cervical cancer.

Advanced Ann Arbor stage and age over 60 years as prognostic predictors in patients with primary cervical lymphoma: a retrospective cohort study and systematic review.

OBJECTIVE: To evaluate the overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) for primary cervical lymphoma (PCL), an extremely rare disease without treatment consensus. METHODS: We conducted a retrospective study included 177 patients, including 169 cases identified from literature review. The Kaplan-Meier methods and Cox regression were used to determine the OS, DSS, RFS, and relevant risk factors. RESULTS: The 5-year OS and 5-year DSS rates were 85.8 and 87.2%, respectively, while the 5-year RFS rate was 85.5%. Diffuse large B-cell lymphoma (DLBCL) was the predominant subtype that comprised 63.8% (113 cases) in this cohort. Multivariate analysis in the DLBCL subgroup revealed that age ≥ 60 years (Odds ratio [OR]: 26.324, 95% Confidence Interval [CI]: 5.090-136.144, P < 0.001) or stage IIIE-IVE (advanced stage) (OR: 4.219, 95%CI: 1.314-13.551, P = 0.016) were the risk factors for OS, while patients with age ≥ 60 years (OR:23.015, 95%CI: 3.857-137.324, P = 0.001), and stage IIIE-IVE (OR: 4.056, 95% CI: 1.137-14.469, P = 0.031) suffered a poor DSS. Chemotherapy and/or radiotherapy improved the OS (P = 0.008), DSS (P = 0.049), and RFS (P = 0.003). However, cancer-directed surgery did not improve the OS, DSS, and RFS. The risk factor was unavailable in other subtypes of PCL due to limited cases. CONCLUSION: The survival outcomes in patients with PCL at early stage were satisfactory, while the advanced disease stage and age ≥ 60 years were the two major factors predicting poor prognosis in DLBCL subtype.

Human papillomavirus (HPV) integration signature in cervical lesions: identification of MACROD2 gene as HPV hot spot integration site.

BACKGROUND: High-risk HPV is clearly associated with cervical cancer. Integration of HPV DNA into the host genome is considered a key event in driving cervical carcinogenesis. However, the mechanism on how HR-HPV integration influences the host genome structure has remained enigmatic. METHODS: In our study, 25 DNA samples including 11 from fresh-frozen cervical carcinomas and 14 from fresh-frozen high-grade squamous intraepithelial lesion (HSILs) were detected using the method of HPV capture combined with next generation sequencing. RESULTS: We calculated the frequency in each viral gene or region and found that breakpoints were prone to occur in L1 and L2 instead of E2 in the cervical cancer (P = 0.0004 and P = 5.15 × 10-40) and HSIL group (P = 2.1 × 10-32 and P = 7.06 × 10-13). The results revealed that HPV16 showed a strong tendency toward intronic region (P = 5.02 × 10-64) but a subtle tendency toward intergenic region (P = 0.04). The most frequent integration site was in the MACROD2 gene (introns 2, 4, 5, 6, 8 and 9), which in MACROD2 functional domain. CONCLUSION: Our results revealed that MACROD2 is HPV hot spot integration site in cervical lesions, and its deficiency alter DNA repair and sensitivity to DNA damage thought impaired PARP1 activity resulting in chromosome instability.

Effects of stem cell factor in follicular fluid and granulosa cells on oocyte maturity and clinical pregnancy.

Stem cell factor (SCF) is implicated in cell growth, proliferation, differentiation, migration, and apoptosis. SCF in follicular fluid (FF) and granulosa cells (GCs) plays a key role in oocyte maturation and clinical pregnancy; however, the exact mechanism is unclear. We aimed to investigate SCF potential in predicting oocyte maturity and clinical pregnancy. We collected 60 FF and 60 GCs samples from different patients with infertility. Real-time polymerase chain reaction and cellular immunofluorescence analyses were used to quantitatively and qualitatively determine SCF concentration in GCs; enzyme-linked immunosorbent assay was used to determine SCF concentration in FF. GC and FF SCF concentrations were positively correlated with metaphase (M)II oocyte proportion and clinical pregnancy (R = 0.280, 0.735 vs R = 0.257, 0.354). SCF concentrations in GCs were significantly higher in the clinical pregnancy group than in the nonclinical pregnancy group. Immunofluorescence analysis showed that SCF expression was higher in the clinical pregnancy and high-MII -oocyte proportion groups. Receiver operating characteristic curve analysis showed that combined SCF and serum anti-Müllerian hormone levels could predict oocyte maturity and clinical pregnancy better than either of these factors alone. SCF concentration in GCs and FF can serve as a predictor of oocyte maturity and clinical pregnancy.

Nanocomposite Polymer Colloids Prepared via Emulsion Polymerization and Stabilized Using Polydopamine-Coated Silica Particles.

Polymer/inorganic colloidal nanocomposites can be prepared via Pickering emulsion polymerization (PEP); however, this process usually requires the use of surfactants, auxiliary comonomers, and volatile organic compounds. Herein, we report a versatile and efficient method for synthesizing stable monodisperse polymer/silica colloidal nanocomposite particles via PEP. First, silica nanoparticles were modified by depositing a multifunctional polydopamine (PDA) film. The outermost PDA film could enhance the precipitation of oligomeric polymer radicals on the silica surface, which is crucial for the preparation of stable polymer/inorganic colloidal nanocomposites via PEP. Notably, this PDA modification approach can employ different initiator systems, such as cationic initiators and redox initiator couples, and can be applied to various monomers and monomer pairs (St, St/nBA, MMA, MMA/nBA, Vac, Vac/nBA). The influence of the concentration and size of polydopamine-coated silica (SiO2@PDA) on the colloidal nanocomposite was investigated. Increasing the diameter of SiO2@PDA and decreasing the concentration of SiO2@PDA both lead to the formation of larger nanocomposite particles. Considering its wide applicability, the proposed PDA modification approach can be applied to other functional inorganic particles to prepare multifunctional polymer/inorganic nanocomposite particles.

Ethnobotanical survey of antifertility medicinal plants in Dali District, Yunnan Province, China.

In recent years, contraceptive medication has been widely used for birth control. It is worth noting that contraceptive medication from botanical source has great potential for clinical use. Yunnan is the province with the most species of plants in China and is known as the "plant kingdom". This study aims to archive herbal remedies traditionally used as antifertility remedies in Dali District, Yunnan Province, P. R. China. The survey was conducted from February 2011 to September 2016 in the population distributed in Dali and the surrounding counties. The data were collected from three groups of practitioners within the study area: therapists using traditional medicines (n = 104), aboriginal families (n = 37), and herbalists in commercial stalls (n = 12), and a total number of 117 plant species were recorded. Among the 117 plant species, 104 of which have been authenticated by a plant taxonomist from the Dali Herbarium. These plants were classified into 98 genera and 54 families, including Leguminosae (12 species), Liliaceae (7 species), Cucurbitaceae, Rosaceae and Rutaceae (5 species, respectively), Malvaceae, Compositae and Euphorbiaceae (4 species, respectively). Our data provides an in-depth delineation of the contraceptive plants used in Dali, which serve as valuable information for the practitioners of traditional Chinese medicine in contraceptive use. In addition, these data also hint that plants from different genus contain contraceptive components, which should be avoided by pregnant women. Future studies are required to identify the active contraceptive components, assess the toxicology, and elucidate the pharmacological mechanism of action.

Circular RNA circ_0011385 promotes cervical cancer progression through competitively binding to miR-149-5p and up-regulating SOX4 expression.

Circular RNAs (circRNAs), emerging as a new type of non-coding RNAs, play important roles in cancers. Instead, the functions and mechanisms of circ_0011385 in cervical cancer (CC) are still inconclusive. Microarray data GSE102686 was downloaded from Gene Expression Omnibus (GEO) database, and were utilized to screen out circRNAs differently expressed in CC tissues. Circ_0011385, miR-149-5p, SRY-box transcription factor 4 (SOX4) mRNA expressions in CC tissues and cells were probed by quantitative real-time PCR (qRT-PCR). CC cell lines with circ_0011385 knockdown were constructed, and he multiplication, migration, invasion, and apoptosis of CC cells were evaluated by cell counting kit-8 (CCK-8) method, transwell assay, and flow cytometry. In addition, the targeting relationships between miR-149-5p and circ_0011385 or SOX4 mRNA 3'UTR were probed by dual-luciferase reporter gene assay and RNA pull-down assay. The regulatory function of circ_0011385 and miR-149-5p on SOX4 expression was studied with western blot. Expressions of circ_0011385 and SOX4 mRNA were raised in CC tissues and cells, while miR-149-5p expression was decreased. Knocking down circ_0011385 restrained the multiplication, migration, and invasion of CC cells and induced the apoptosis. Circ_0011385 directly targeted miR-149-5p, and SOX4 was the target of miR-149-5p, which could be positively regulated by circ_0011385. Circ_0011385 elevates SOX4 expression by targeting miR-149-5p, thus participating in promoting the malignant biological behaviors of CC cells.

Zuogui Wan alleviated maternal kidney-yin deficiency-induced thymic epithelial cell dysfunction in newborn rats through Wnt/ß-catenin signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Kidney-yin deficiency (KYD) during pregnancy is common and associated with possibility of thymus hypoplasia in neonates. Zuogui Wan (ZGW) is a classic traditional medicine to treat KYD. AIM OF STUDY: The Wnt/ß-catenin signaling pathway is essential for thymic epithelial cell (TEC) viability, function and for thymus integrity. We evaluated whether maternal diets with ZGW in KYD rats ameliorates epithelial cell dysfunction in the fetal thymus, and investigated its underlying mechanism in which the Wnt/ß-catenin signaling pathway is involved. MATERIALS AND METHODS: Rats were randomly assigned to four groups (n = 8). Two experimental groups received KYD induction with or without ZGW supplementation. The other 2 vehicle groups were sham operated and administrated with normal saline or ZGW. KYD was established using periodically chronic shaken stimulus and threaten stress. Success of the model induction was evaluated by the general observation, changing of the body weight and plasma thyroxine level. Then, pregnant of vehicle and KYD rats were fed with or without ZGW-supplemented diet throughout the F1 gestation. Postnatal thymi samples were obtained after delivery for histological examination. In vitro, TECs of the newborn rats whose mother suffered KYD were isolated, and cultured using the serum containing ZGW with or without the supplement of Wnt4/ß-catenin pathway inhibitor ICG-001. Cell viability was evaluated by CCK-8 assay. Meanwhile, the thymi tissues and TECs were collected for biochemical analysis. Levels of thymosin ß4 (TMSß4) and thymosin α1 (Tα1) were detected by ELISA assay. The mRNA and protein expression of Wnt4, ß-catenin, and Foxn1 were determined by RT-qPCR and Western blot respectively. RESULTS: In vivo, KYD resulted in significantly increased apoptosis of TECs and atrophy of the thymi, especially in the medullary zone. The morphological changes observed in KYD rats were ameliorated by ZGW treatment. Meanwhile, the decreased TMSß4, Tα1, Wnt4, ß-catenin, and Foxn1 levels in KYD rats were also significantly alleviated by ZGW administration. In vitro, elevated TMSß4 and Tα1 levels accompanied with upregulated Wnt4, ß-catenin, and Foxn1 expressions in the TECs were observed after ZGW intervention, however, which were significantly downregulated by ICG-001 supplement. CONCLUSIONS: Maternal kidney-yin deficiency could result in TEC dysfunction in newborn rats. ZGW was able to improve the growth and development of TEC, potentially by regulating the Wnt/ß-catenin pathway.

IL-1ß promotes cervical cancer through activating NF-κB/CCL-2.

Cervical cancer is a malignancy with high morbidity and mortality among women. Interleukin (IL)-1ß, chemokine (C-C motif) ligand 2 (CCL-2), and activation of NF-κB have been proven to be closely related to the progression of various tumors. However, their role in cervical cancer remains unclear. Cell proliferation, migration, and invasion were detected using MTT, wound healing, and transwell assays. Western blotting and qRT-PCR were used to measure expression of target genes. IL-1ß greatly promoted the release of CCL-2 from HeLa cells. Activation of NF-κB and phosphorylated NF-κB (p65) nuclear translocation were accelerated by IL-1ß. TPCA-1, a blocker of NF-κB, significantly inhibited the release of CCL-2 from HeLa cells. TPCA-1 markedly reversed the promotional effect of IL-1ß on viability of HeLa cells. IL-1ß increased the cell migration, proliferation, and invasion of HeLa cells through targeting the NF-κB/CCL-2 pathway. IL-1ß/NF-κB/CCL-2 might be a promising treatment target for cervical cancer treatment and prevention.

Circ_0001247 functions as a miR-1270 sponge to accelerate cervical cancer progression by up-regulating ZEB2 expression level.

BACKGROUND: There is increasing evidence that circular RNA (circRNA) disorders have an impact on the progression of various malignancies. The expression characteristics, function and underlying mechanism of circ_0001247 in cervical cancer (CC) have not been confirmed. METHODS: GSE147483 datasets of circRNAs expression in CC cell line and normal cervical cell line were retrieved from GEO database, and the circRNA with significant difference was selected; circ_0001247, miR-1270, and Zinc finger E-box binding homeobox 2 (ZEB2) expressions in CC tissues and cell lines were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) assay; cell counting kit-8 (CCK-8) assay and BrdU assay were applied to monitor the proliferative ability of CC cells; Transwell assay was conducted to examine the migration and invasion of CC cells, and flow cytometry was used to evaluate the apoptosis; Western blot assay was adopted to detect ZEB2 protein expressions; dual-luciferase report gene assay was used to verify the targeting relationship between circ_0001247 and miR-1270, and miR-1270 and the 3'UTR of ZEB2. RESULTS: Analysis of GSE147483 suggested that circ_0001247 could probably be an oncogenic circRNA in CC. Compared with that in adjacent tissues and normal cervical epithelial cells, circ_0001247 expression in CC tissues and cell lines was significantly increased; knocking down circ_0001247 expression could inhibit the proliferation and metastasis of CC cells, and promote apoptosis, while circ_0001247 overexpression worked oppositely; circ_0001247 sponged miR-1270 in CC cells; miR-1270 diminished the promoting effect of circ_0001247 by inactivating the ZEB2. CONCLUSION: Circ_0001247 promotes progression of CC by sponging miR-1270 to upregulate ZEB2 expression level.

Graphene Quantum Dots with Pyrrole N and Pyridine N: Superior Reactive Oxygen Species Generation Efficiency for Metal-Free Sonodynamic Tumor Therapy.

Those responsible for the development of sonosensitizers are faced with a dilemma between high sonosensitization efficacy and good biosecurity that limited the development of sonodynamic therapy (SDT). Herein, inspired by the intriguing therapeutic features of SDT and the potential catalytic activity of graphene quantum dots, the potential of N-doped graphene quantum dots (N-GQDs) to act as a sonosensitizer is demonstrated. The superior sonosensitization effect of N-GQDs is believed to be three to five times higher than that of traditional sonosensitizers (such as porphyrin, porphyrin Mn, porphyrin Zn, TiO2 , etc.). More importantly, the sonochemical mechanism of N-GQDs is revealed. Pyrrole N and pyridine N are believed to form catalytic centers in sonochemical processing of N-GQDs. This knowledge is important from the perspective of understanding the structure-dependent SDT enhancement of carbon nanostructure. Moreover, N-GQDs modified by folic acid (FA-N-GQDs) show a high marker rate for tumor cells (greater than 96%). Both in vitro and in vivo therapeutic results have exhibited high tumor inhibition efficiency (greater than 90%) of FA-N-GQDs as sonosensitizers while the oxidative stress response of tumor cells is activated through the PEX pathway and induced apoptosis via the p53 pathway.

Carbon-Based Quantum Dots with Solid-State Photoluminescent: Mechanism, Implementation, and Application.

Carbon-based quantum dots (CQDs), including spherical carbon dots and graphene quantum dots, are an emerging class of photoluminescent (PL) materials with unique properties. Great progress has been made in the design and fabrication of high-performance CQDs, however, the challenge of developing solid-state PL CQDs have aroused great interest among researchers. A clear PL mechanism is the basis for the development of high-performance solid-state CQDs for light emission and is also a prerequisite for the realization of multiple practical applications. However, the extremely complex structure of a CQD greatly limits the understanding of the solid-state PL mechanism of CQDs. So far, a variety of models have been proposed to explain the PL of solid-state CQDs, but they have not been unified. This review summarizes the current understanding of the solid-state PL of solid-state CQDs from the perspective of energy band theory and electronic transitions. In addition, the common strategies for realizing solid-state PL in CQDs are also summarized. Furthermore, the applications of CQDs in the fields of light-emitting devices, anti-counterfeiting, fingerprint detection, etc., are proposed. Finally, a brief outlook is given, highlighting current problems, and directions for development of solid-state PL of CQDs.

Polarizing Graphene Quantum Dots toward Long-Acting Intracellular Reactive Oxygen Species Evaluation and Tumor Detection.

The evaluation of intracellular reactive oxygen species (ROS) would greatly deepen the understanding of cell metabolism/proliferation and tumor detection. However, current long-acting level tracking techniques for intracellular ROS remain unsuited to practical applications. To solve this problem, we synthesized cyclotriphosphazene-doped graphene quantum dots (C-GQDs) whose quantum yield is highly sensitive to ROS (increased by 400% from 0.12 to 0.63). Electron cloud polarization of oxidized cyclotriphosphazene rings in C-GQDs is confirmed to account for this novel optical property by density functional theory calculations and experimental results. In combination with excellent biological stability, C-GQDs achieve a long-acting evaluation of intracellular ROS level (more than 72 h) with an accuracy of 98.3%. In addition, recognition rates exceeding 90% are demonstrated to be feasible for eight kinds of tumor cell lines cultured with C-GQDs, which can also be expanded to in vivo detection. C-GQDs also show a high recognition rate (82.33%) and sensitivity (79.65%) for tumor cells in blood samples.

On-Demand Oil-Water Separation by Environmentally Responsive Cotton Fabrics.

Environmentally responsive cotton fabrics were fabricated by dip-coating ABC miktoarm star terpolymers, which contain reactive poly(3-triisopropyloxysilylpropyl methacrylate) blocks, hydrophobic poly(dimethylsiloxane) (PDMS) blocks, and hydrophilic poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) blocks. The functionalized cotton fabrics with perfectly alternating PDMS and PDMAEMA blocks show underoil superhydrophobicity and underwater superoleophobicity. The wettability and permeability of the functionalized fabrics can be readily adjusted by the contacting medium. More interestingly, surface reconstruction causes a reduction in the breakthrough pressure of the nonwetting phase. The adaptive permeability endows the functionalized cotton fabrics with the capability to separate heavy oil-water-light oil ternary mixtures.

In situ synthesis of monolayer graphene on silicon for near-infrared photodetectors.

Direct integration of monolayer graphene on a silicon (Si) substrate is realized by a simple thermal annealing process, involving a top copper (Cu) layer as the catalyst and an inserted polymethylmethacrylate (PMMA) as the carbon source. After spin-coating the PMMA carbon source on the Si substrate, the Cu catalyst was deposited on PMMA/Si by electron beam evaporation. After that, graphene was directly synthesized on Si by decomposition and dehydrogenation of PMMA and the catalyzation effect of Cu under a simple thermal annealing process. Furthermore, under an optimized growth condition, monolayer graphene directly formed on the Si substrate was demonstrated. Utilizing the as-grown graphene/Si heterojunction, near-infrared photodetectors with high detectivity (∼1.1 × 1010 cm Hz1/2 W-1) and high responsivity (50 mA W-1) at 1550 nm were directly fabricated without any post-transfer process. The proposed approach for directly growing graphene on silicon is highly scalable and compatible with present nano/micro-fabrication systems, thus promoting the application of graphene in microelectronic fields.

Promising Fast Energy Transfer System Between Graphene Quantum Dots and the Application in Fluorescent Bioimaging.

Tunable photoluminescence performance of graphene quantum dots (GQDs) is one of the most important topics for the development of GQDs. In this paper, we report lattice-doped GQDs (boron-doped GQDs (B-GQDs) and phosphorus-doped GQDs (P-GQDs)). Because of the matched band structure, the fast energy transfer between blue-emitted B-GQDs (emission wavelength: 460 nm) and orange-emitted P-GQDs (emission wavelength: 630 nm) can induce an efficient fluorescence emission in P-GQDs once B-GQDs are excited under the optimal excitation wavelength of 460 nm. Moreover, with the effective energy transfer, the quantum yield of P-GQDs increased to 0.48, which is much higher than that of pure P-GQDs. We also demonstrated the potentials of this system for fluorescent bioimaging in vitro.

Tailoring the Wettability of Colloidal Particles for Pickering Emulsions via Surface Modification and Roughness.

Pickering emulsions are water or oil droplets that are stabilized by colloidal particles and have been intensely studied since the late 90s. The surfactant-free nature of these emulsions has little adverse effects such as irritancy and contamination of environment and typically exhibit enhanced stability compared to surfactant-stabilized emulsions. Therefore, they offer promising applications in cosmetics, food science, controlled release, and the manufacturing of microcapsules and porous materials. The wettability of the colloidal particles is the main parameter determining the formation and stability of Pickering emulsions. Tailoring the wettability by surface chemistry or surface roughness offers considerable scope for the design of a variety of hybrid nanoparticles that may serve as novel efficient Pickering emulsion stabilizers. In this review, we will discuss the recent advances in the development of surface modification of nanoparticles.