Fast and High-Throughput Evaluation of Photodynamic Effect by Monitoring Specific Protein Oxidation with MALDI-TOF Mass Spectrometry

In antibacterial practices by photodynamic treatment, bacteria are incubated with photosensitizers and then oxidized to death by generating reactive oxygen species (ROS) under light irradiation. Generally, Luria-Bertani (LB) agar colony is a conventional method to evaluate the photodynamic effect. However, this method is time consuming, easily disturbed by pollutants, and limited to the analysis of a pure bacteria sample. Herein, we introduce a novel method of photodynamic effect evaluation through in situ detection of specific protein oxidation by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) with only 1 μL of sample in a fast (less than 1 min per sample) and high-throughput (up to 384 samples per run) way. The oxidation rates of specific proteins stayed highly consistent with bactericidal rates and thus MALDI-TOF MS might be able to replace the LB agar colony to evaluate the photodynamic effect. With the present method, several experimental conditions including different photosensitizer types, dosage controls, and different illumination times were easily screened to optimize photodynamic effect. Photodynamic effects of various bacteria species, cancer cells, and even mixture samples were also evaluated. The results demonstrate the promising application of MALDI-TOF MS in evaluating the photodynamic effect of each component in a mixture sample without any separation or purification, which could not be achieved by the traditional LB agar colony method.

[Clinical strategies for preservation of the exposed implant in chronic wounds and wound repair]

Objective: To explore the clinical strategies for preservation of the exposed implant in chronic wounds and wound repair. Methods: From January 2016 to January 2019, totally 8 patients (4 males and 4 females, aged 10 to 73 years) sustaining postoperative chronic wounds with exposed implants were admitted to the Fourth Medical Center of PLA General Hospital. There were 2 cases of abdominal patch exposure after abdominal trauma surgery, 2 cases of titanium plate exposure post craniocerebral surgery, 3 cases of internal fixator exposure post orthopedic surgery, and 1 case of cerebrospinal fluid drainage tube exposure after craniocerebral surgery. The wound exudate was collected for bacterial culture on admission. On the basis of glycemic control and correction of anemia and hypoproteinemia, thorough wound debridement was performed as soon as possible and the wound area after debridement ranged from 2.0 cm×0.5 cm to 6.0 cm×5.0 cm. The wounds of 4 patients were immediately closed after debridement, including 1 case by primary closure, 1 case by primary closure after local filling of platelet rich plasma gel, and 2 cases by local flap transplantation, with flap size of 10.0 cm×8.0 cm and 12.0 cm×8.0 cm, respectively. The donor sites of flaps were sutured directly and all the incisions were treated with continuous vacuum sealing drainage (VSD) after surgery. The other 4 patients were treated with continuous VSD after debridement to improve the wound bed. The wound of 1 case healed gradually, 1 case received direct wound suturing, and the wounds of 2 cases were repaired with thin split-thickness skin grafts from the thigh or the head. The results of bacterial culture of wound exudate on admission, wound healing post surgery, and follow-up were observed and recorded. Results: The bacterial culture of wound exudate on admission was positive in 6 patients, and 10 strains of bacteria were isolated with Staphylococcus epidermidis as the main pathogen. All the skin grafts or flaps of patients survived post surgery, with the incisions and wounds healed and all the implants preserved. After 1 to 3 years of follow-up, no recurrence of wound was found in any patient. Conclusions: The postoperative chronic wounds with exposed implants can be closed in primary stage by direct suturing or flap transplantation if it is clean enough on the basis of thorough debridement. The wounds with large defects or serious infection can be treated with continuous VSD firstly and then closed with direct suturing or skin grafting for delayed wound closure, thereby to reach the treatment goal of preserving the implants and repairing the wounds simultaneously.

[Selection and effects of flap/myocutaneous flap repair methods for the defect after perineum tumor resection]

Objective: To explore the selection and effects of flap/myocutaneous flap repair methods for the defect after perineum tumor resection. Methods: From January 2011 to February 2017, 31 patients with vulvar tumor who were admitted to Hunan Cancer Hospital underwent repair of wound after tumor resection with various flaps/myocutaneous flaps. The patients were composed of 5 males and 26 females, aged 39-76 years, with 27 vulvar cancer and 4 Paget's disease in primary diseases. The size of defects after vulvar tumor radical resection ranged from 8.0 cm×4.5 cm to 27.5 cm×24.0 cm. According to the theory of perforasome, the defects were repaired by the external pudendal artery perforator flap, deep inferior epigastric artery perforator flap, rectus abdominis myocutaneous flap, anterolateral thigh flap, internal pudendal artery perforator flap, gracilis myocutaneous flap, and profunda artery perforator flap based on the specific size and location of perineum and groin where the defect was located. According to the blood supply zone of flap, totally 17 local translocation flaps, 18 axial flaps/myocutaneous flaps, and 7 V-Y advancement flaps were resected, with an area of 7.0 cm×4.0 cm to 21.0 cm×13.0 cm. All the flaps/myocutaneous flaps were transferred in pedicled fashion, and the donor sites were closed without tension. The number of flaps/myocutaneous flaps, wound closure, flaps/myocutaneous flaps survival, and follow-up were observed and recorded. Results: Altogether 42 flaps/myocutaneous flaps were harvested in 31 patients. Two flaps/myocutaneous flaps were used in 11 cases for large circular defect repair. All the defects achieved tension-free primary closure. The blood supply of 32 flaps/myocutaneous flaps was good, while insufficient blood supply was noted in the other 10 flaps/myocutaneous flaps. Seventeen flaps/myocutaneous flaps survived smoothly. Wound dehiscence occurred in 5 flaps/myocutaneous flaps 8 to 14 days postoperatively, which was healed with dressing change. Temporary congestion was noted in 7 flaps/myocutaneous flaps 2 to 5 days postoperatively, which recovered without special treatment. Three flaps/myocutaneous flaps had infection 7 to 15 days postoperatively, two of which recovered after dressing change, while the other one had partial necrosis and received debridement and direct closure. Two flaps/myocutaneous flaps were totally necrotic 8 to 15 days postoperatively, which were repaired with pedicled rectus abdominis myocutaneous flap after debridement. Seven flaps/myocutaneous flaps had partial necrosis 7 to 20 days postoperatively and were healed after dressing change. Twenty-four patients were followed up for 9-38 months. The color of flaps/myocutaneous flaps was similar to that of the surrounding skin, the shape of vulva was natural, the movement of hip joint was not limited, the function of micturition and defecation was not affected, and tumor recurrence was noted in 3 patients. Conclusions: For the complicated large defect after perineum tumor resection, the flexible application of different forms of flaps/myocutaneous flaps to repair according to different areas regains the appearance and function. However, there are many complications, so it is necessary to further strengthen the postoperative care.

0913 Ambulatory Blood Pressure Monitoring In Children With Obstructive Sleep Apnea Syndrome

Introduction

This study was performed to investigate the differences in blood pressure among different groups of snoring children and among different sleep stages.In recent years, the incidence of OSAS in children has increased year by year. Blood pressure research of OSAS children can better understand the occurrence of OSAS related complications. Early detection and intervention of blood pressure changes in children with OSAS can effectively reduce the incidence of cardiovascular disease in adulthood and lower the disease burden.

Methods

Habitually snoring children (snoring frequency of ≥3 nights per week) aged 3to 11 years were recruited from Beijing Children’s Hospital, Capital Medical University from 1 January 2017 to 30 June 2018. All children underwent polysomnography, and their blood pressure was monitored and calculated by the pulse transit time. The children were divided into those with primary snoring (PS), mild obstructive sleep apnea syndrome (OSAS), and moderate to severe OSAS according to their obstructive apnea-hypopnea index (OAHI).

Results

In total, 140 children were recruited. Ninety-seven had PS, 24 had mild OSAS, and 19 had moderate to severe OSAS. There were no differences in age, sex, or body mass index z-score among the groups. Statistically significant differences were found in the OAHI, oxygen desaturation index 3%, respiratory arousal index, and lowest oxygen saturation among the three groups. Children with moderate to severe OSAS had higher systolic and diastolic blood pressure than those with mild OSAS and PS (P < 0.001). In all children, systolic and diastolic blood pressure was higher in the rapid eye movement (REM) sleep stage than in the non-REM sleep stage (P < 0.05).

Conclusion

Children with moderate to severe OSAS had higher blood pressure than those with PS and mild OSAS. Blood pressure in the REM sleep stage was higher than that in other sleep stages in all groups of children.

Support

The Pediatric Medical Coordinated Development Center of Beijing Hospitals Authority (XTYB201807);Capital Health Research and Development of Special Funding (2018-1-2091);National Key Research and Development Plan (2017YFC0112502)

[Effects of pedicled rectus abdominis myocutaneous flap combined with free deep inferior epigastric artery perforator flap carrying inguinal lymphatic flap in breast reconstruction and upper limb lymphedema treatment post radical mastectomy]

Objective: To explore the effects of pedicled rectus abdominis myocutaneous (PRAM)flap combined with free deep inferior epigastric artery perforator (DIEAP) flap carrying inguinal lymphatic flap in breast reconstruction and upper limb lymphedema treatment post radical mastectomy. Methods: From October 2014 to September 2016, 9 patients with upper limb lymphedema after mastectomy were treated with PRAM flap combined with free DIEAP flap carrying inguinal lymphatic flap for breast reconstruction and upper limb lymphedema treatment in Hunan Province Cancer Hospital. The patients were all females, aged 34-66 (44±7) years. The location of deep inferior epigastric artery perforator was detected by audible Doppler ultrasound blood stream detector and computed tomography angiography for designing combined tissue flap, with length of (25.32±0.27) cm, width of (13.14±0.76) cm, and thickness of (3.55±0.34) cm. The donor site of combined tissue flap was closed by suturing, and two or more tubes for negative pressure drainage were placed according to the situation of donor site and recipient site. Operation time and average placing time of negative pressure drainage tube, postoperative condition of combined tissue flap and the donor site, reconstructed breast condition, recovery of upper limb lymphedema were documented and followed up. Results: The operation time was 290-420 (396±55) min. The average retaining time of negative pressure drainage tube in breast was 5.9 d, while the average retaining time of negative pressure drainage tube in abdomen was 4.3 d. Ecchymoma occurred in DIEAP flap of one patient and in the flap donor site of another patient. Delayed healing was also seen in the rectus abdominis myocutaneous flap of a patient, which healed eventually after dressing change, and the other flaps survived well. The appearance of reconstructed breast was good with good elasticity, and no contracture or deformation occurred in the tissue flap. The upper limb lymphedema in 7 patients was alleviated in varying degrees, with 2.0-4.0 cm reduction in circumference. During follow-up of 12-24 months of 9 patients, averaged 17.5 months, with 6 patients received long term bandage pressure therapy and physical therapy to the affected limbs after operation and all patients were satisfied with appearances of the affected limbs. Neuropathic pain in affected limbs was significantly relieved in 2 patients and stopped aggravating in the other 2 patients. Only linear scar was seen in the donor site of abdomen without affecting obviously the function of abdomen. Conclusions: The PRAM flap combined with free DIEAP flap carrying inguinal lymphatic flap is an effective way for breast reconstruction and upper limb lymphedema treatment post mastectomy.

Design of superior phototheranostic agents guided by Jablonski diagrams

This review summarizes how Jablonski diagrams guide the design of advanced organic optical agents and improvement of disease phototheranostic efficacies.

Bone inflammation and chronic recurrent multifocal osteomyelitis

Chronic recurrent multifocal osteomyelitis (CRMO) is a sporadic condition of inflammatory bone pain that occurs as recurrent flares because of osteomyelitis, which presents in the form of multiple aseptic foci. The estimated prevalence of CRMO is 1-2 per million, affecting mostly children, in the age group of 2 to 17. Main symptoms of CRMO are bone inflammation and pain, which are generally worse at night. Other symptoms seen on radiographs indicate osteolytic lesions surrounded by sclerosis, at later stages of the disease. Markers of inflammation, viz. tumor necrosis factor a and C-reactive protein are elevated in many cases. Because of similar symptoms, differential diagnosis is needed to confirm CRMO from infectious osteomyelitis, bone tumors, and other diseases. The genetic component is likely in some cases such as Majeed syndrome, deficiency of IL-1 antagonist, etc. Imaging is the essential part of diagnosing CRMO, and magnetic resonance imaging of the whole body is the most widely used and recommended method for the evaluation of multiple foci, as compared to radiography for reasons of sensitivity as well as prevention of excessive exposure of affected children to radiation. CRMO is considered an autoimmune and auto-inflammatory disorder, but its precise pathophysiology is not clear. Current treatment options are non-steroid anti-inflammatory drugs like naproxen, as the primary choice, and the bisphosphonates such as pamidronate as the second choice, to counter the symptoms and to reduce bone lesions. The surgical option is the choice for recalcitrant cases, even though recurrence may still be a problem.

Experience of pediatric urogenital tract inserted objects: 10-year single-center study

INTRODUCTION

Urogenital tract foreign bodies (FBs) have been rarely reported in children, and the management is still challenging.

OBJECTIVE

The aim of this study is to review a 10-year experience with urogenital tract FBs in a single center.

PATIENTS AND METHODS

The authors reviewed the records of children suspected with urogenital tract FBs and first admitted to the hospital, including demographic characteristics, presenting symptoms, methods of diagnosis, and management. The authors compared the surgery strategies in different locations of FBs and age, and the locations of FBs in different age groups.

RESULTS

Two hundred and thirty-nine cases were reviewed, and 188 were confirmed to retain urogenital tract FBs (150 girls and 38 boys). The number of the patients increased progressively in the last 10 years and mainly concentrated in spring and summer in the last 4 years. The peak ages were 3-5 years old and 9-13 years old. General anesthesia surgeries were performed on 20 patients (Fig. 1). Vagina FBs were more likely to require day surgery, whereas bladder FBs required surgery in hospital. Patients younger than 6 years were more likely to be girls with vagina FBs, and patients older than 11 years were more likely to be boys with bladder FBs.

DISCUSSION

Urogenital tract FBs in children is a great challenge. As the vagina is shorter and wider than the urethra, girls with vagina FBs are usually treated by day surgery and adolescent boys of urethra FBs are treated by hospital surgery. Misdiagnosis may occur when patients conceal FBs insert history, have severe urinary tract infections, or have previous surgery history. Ultrasonography helps to reduce misdiagnosis. FBs should be taken into consideration when patients have new symptoms after hypospadias repair, and postoperative changes of hypospadias repair, such as urinary calculi, have been excluded. Appropriate surgery techniques, based on the size, nature, and location of FBs, should be performed for complete removal of FBs with minimal complications to reduce secondary injury. Sharp FBs could be migrated among the digestive system, urogenital system, and deep pelvic. If the procedure is difficult, patients with a stable needle can be conservatively managed with close follow-up. Nevertheless, symptomatic patients should be treated actively.

CONCLUSION

The awareness of potential severity of pediatric urogenital tract FBs should be raised. Appropriate toys and timely sex education help prevent children from urogenital tract FBs insertion. Selecting appropriate techniques for particular situations is the best way to reduce secondary injury, especially for cases with migrated FBs (needles), magnetic FBs, and postoperative FBs.

IgM in human immunity to Plasmodium falciparum malaria

Most studies on human immunity to malaria have focused on the roles of immunoglobulin G (IgG), whereas the roles of IgM remain undefined. Analyzing multiple human cohorts to assess the dynamics of malaria-specific IgM during experimentally induced and naturally acquired malaria, we identified IgM activity against blood-stage parasites. We found that merozoite-specific IgM appears rapidly in Plasmodium falciparum infection and is prominent during malaria in children and adults with lifetime exposure, together with IgG. Unexpectedly, IgM persisted for extended periods of time; we found no difference in decay of merozoite-specific IgM over time compared to that of IgG. IgM blocked merozoite invasion of red blood cells in a complement-dependent manner. IgM was also associated with significantly reduced risk of clinical malaria in a longitudinal cohort of children. These findings suggest that merozoite-specific IgM is an important functional and long-lived antibody response targeting blood-stage malaria parasites that contributes to malaria immunity.

Spatiotemporal predictions of obesity prevalence in Chinese children and adolescents: based on analyses of obesogenic environmental variability and Bayesian model

OBJECTIVE

To find variations in Chinese obesogenic environmental priorities from 2000 to 2011, predict spatiotemporal distribution of obesity prevalence aged 7-17 years in 31 provinces, and provide foundations for policy-makers to reduce obesity in children and adolescents.

METHODS

Based on data examination of provincial obesity prevalence aged 7-17 years from three rounds of China Health and Nutrition Surveys (in 9 [2000], 9 [2006], and 12 [2011] provinces) and corresponding years' environments in 31 provinces from China Statistical Yearbooks and other sources, 12 predictors were selected. We used 30 surveyed provinces in three rounds as training samples to fit three analytic models with partial least-square regressions and prioritized predictors by variable importance projection to find variations. And fitted a spatiotemporal prediction model with Bayesian analysis to infer in space-time.

RESULTS

Variations of obesogenic environmental priorities were found at different times. A Bayesian spatiotemporal prediction model with deviance information criterion of 155.60 and statistically significant (P < 0.05) parameter estimates of intercept (-717.0400, 95% confidence intervals [CI]: -1186.0300, -248.0480), year (0.3584, CI: 0.1245, 0.5924), square of food industry level (0.0003, CI: 0.0002, 0.0004), and log (healthcare) (5.3742, CI: 2.5138, 8.2347) was optimized. Totally inferred average obesity prevalence among children and adolescents were 2.23%, 5.11%, 10.77%, 12.20%, 13.99%, and 17.58% in 31 provinces in China in 2000, 2006, 2011, 2015, 2020, and 2030, respectively. Obesity in north and east of China clusters on predicted maps.

CONCLUSIONS

Obesity prevalence in children and adolescents in China is rapidly increasing, growing at 0.3584% annually from 2000 to 2011. From longitudinal observation, prevalence was significantly influenced by food industry ("Amplifier") and healthcare service ("Balancer"). Targeted interventions in north and east of China are pressing. Further researches on the mechanisms underlying the influence of food industry, healthcare service, and so on in children and adolescents are needed.

let-7i inhibits proliferation and migration of bladder cancer cells by targeting HMGA1

Background

Let-7 is one of the earliest discovered microRNAs(miRNAs) and has been reported to be down-regulated in multiple malignant tumors. The effects and molecular mechanisms of let-7i in bladder cancer are still unclear. This study was to investigate the effects and potential mechanisms of let-7i on bladder cancer cells.

Methods

Total RNA was extracted from bladder cancer cell lines. The expression levels of let-7i and HMGA1 were examined by quantitative real-time PCR. Cell viability was detected using the CCK-8 and colony formation assays, while transwell and wound healing assays were used to evaluate migration ability. Luciferase reporter assay and western blot were used to confirm the target gene of let-7i.

Results

Compared with the SV-40 immortalized human uroepithelial cell line (SV-HUC-1), bladder cancer cell lines T24 and 5637 had low levels of let-7i expression, but high levels of high mobility group protein A1 (HMGA1) expression. Transfection of cell lines T24 and 5637 with let-7i mimic suppressed cell proliferation and migration. Luciferase reporter assay confirmed HMGA1 may be one of the target genes of let-7i-5p. Protein and mRNA expression of HMGA1 was significantly downregulated in let-7i mimic transfected cell lines T24 and 5637.

Conclusions

Up-regulation of let-7i suppressed proliferation and migration of the human bladder cancer cell lines T24 and 5637 by targeting HMGA1. These findings suggest that let-7i might be considered as a novel therapeutic target for bladder cancer.

Visualize Embryogenesis and Cell Fate Using Fluorescent Probes with Aggregation-Induced Emission

Horseradish peroxidase (HRP) and fluorogen-dextran conjugate are tracers extensively used for injection-based lineage tracing. However, HRP is sensitive to proteolytic digestion, whereas the high-molecular-weight dextran may have antigenicity. Small molecular tracers can overcome these problems, but they usually diffuse from labeled cells, causing inaccurate information. Herein, we developed a small-molecular-weight fluorogen with aggregation-induced emission (AIEgen) for embryonic cell tracing with strong signals against tracer dilution caused by cell division. Once injected into the ancestor cells, the AIEgen can be entrapped in the cells without leakage because of the two hydrophilic and neutral arms. Consequently, it can specifically trace the progenies of the treated ancestor cells. More importantly, the operating concentration of AIEgen can be much higher than that of fluorogens with aggregation-caused quenching, which provides bright signals in daughter cells during embryonic cell tracing, thus overcoming the problem of fast signal degradation typically encountered with the use of traditional cell tracers.

[Advances in epidemiology and serum markers for the noninvasive diagnosis of nonalcoholic fatty liver disease]

The global prevalence rate of nonalcoholic fatty liver disease (NAFLD) has increased year by year, and it has become the number one cause for chronic liver disease in China. In addition, the trend of NAFLD has become more pronounced and evident in female gender and younger age group. The long-term persistence of fatty liver disease may cause serious consequences. There are no accepted diagnostic criteria for diagnosing noninvasive diagnosis of NAFLD. Alpha-ketoglutarate is a newly discovered serological marker of high diagnostic value and considered the most valuable potential biomarker along with cytokeratine-18 (CK-18).

Aggregation-Induced Emission (AIE) Dots: Emerging Theranostic Nanolights

Theranostic nanolights refer to luminescent nanoparticles possessing both imaging and therapeutic functions. Their shape, size, surface functions, and optical properties can be precisely manipulated through integrated efforts of chemistry, materials, and nanotechnology for customized applications. When localized photons are used to activate both imaging and therapeutic functions such as photodynamic or photothermal therapy, these theranostic nanolights increase treatment efficacy with minimized damage to surrounding healthy tissues, which represents a promising noninvasive nanomedicine as compared to conventional theranostic approaches. As one of the most promising theranostic nanolights, organic dots with aggregation-induced emission (AIE dots) are biocompatible nanoparticles with a dense core of AIE fluorogens (AIEgens) and protective shells, whose sizes are in the range of a few to tens of nanometers. Different from conventional fluorophores that suffer from aggregation-caused quenching (ACQ) due to π-π stacking interaction in the aggregate state, AIEgens emit strongly as nanoaggregates due to the restriction of intramolecular motions. Through precise molecular engineering, AIEgens could also be designed to show efficient photosensitizing or photothermal abilities in the aggregate state. Different from ACQ dyes, AIEgens allow high loading in nanoparticles without compromised performance, which makes them the ideal cores for theranostic nanolights to offer high brightness for imaging and strong photoactivities for theranostic applications. In this Account, we summarize the recent advance of AIE dots and highlight their great potential as theranostic nanolights in biomedical applications. Starting from the design of AIEgens, the fabrication of AIE dots and their bioimaging applications are discussed. The exceptional advantages of superbrightness, high resistance to photobleaching, lack of emission intermittency, and excellent biocompatibility have made them reliable cross platform contrast agents for different imaging techniques such as confocal microscopy, multiphoton fluorescence microscopy, super-resolution nanoscopy, and light-sheet ultramicroscopy, which have been successfully applied for cell tracking, vascular disease diagnosis, and image-guided surgery. The integration of therapeutic functions with customized AIEgens has further empowered AIE dots as an excellent theranostic platform for image-guided phototherapy. Of particular interest is AIE photosensitizer dots, which simultaneously show bright fluorescence and high photosensitization, yielding superior performance to commercial photosensitizer nanoparticles in image-guided therapy. Further development in multiphoton excited photodynamic therapy has offered precise treatment with up to 5 μm resolution at 200 μm depth, while chemiexcited photodynamic therapy has completely eliminated the limitation of penetration depth to realize power-free imaging and therapy. With this Account, we hope to stimulate more collaborative research interests from different fields of chemistry, materials, biology, and medicine to promote translational research of AIE dots as the theranostic nanolights.

Artemisinin and AIEgen Conjugate for Mitochondria-Targeted and Image-Guided Chemo- and Photodynamic Cancer Cell Ablation

Cell organelle targeting is a promising approach for cancer therapy. We herein report a light-up probe (tetraphenylethenethiophene (TPETH)-Mito-1ART) to co-deliver artemisinin (ART) and an aggregation-induced emission (AIE) photosensitizer to cancer cell mitochondria for image-guided combination cancer cell ablation. This probe contains a TPETH core, two mitochondria targeting arms with ART on one arm, which show high specificity toward cancer cells over normal ones, predominant accumulation, and fluorescence turn-on in mitochondria. The fresh heme produced in mitochondria quickly activates ART, and the direct generation of reactive oxygen species at mitochondria promotes photodynamic therapy (PDT) performance. The incorporation of ART and PDT leads to a largely improved cancer cell ablation efficacy with a synergistic effect, which could quickly depolarize mitochondrial membrane and largely reduce cancer migration activity. This co-delivery strategy provides great potentials for subcellular organelle-targeted and image-guided combination cancer cell ablation.

Polymeric nanorods with aggregation-induced emission characteristics for enhanced cancer targeting and imaging

Polymeric nanorods loaded with AIEgens are synthesized via nano-precipitation under ultrasound sonication, where prolonged sonication time could induce a nanodot-to-nanorod transition. These AIE nanorods, but not the nanodots, could be selectively internalized into cancer cells, which show better tumor accumulation, higher tumor penetration and more efficient in vivo cancer cell uptake.

Organic nanoparticles with ultrahigh quantum yield and aggregation-induced emission characteristics for cellular imaging and real-time two-photon lung vasculature imaging

Organic nanoparticles with a high quantum yield of 90% and aggregation-induced emission characteristics were prepared for cellular imaging and real-time two-photon vasculature imaging of the lungs.

Aggregation-Induced Emission Probe for Specific Turn-On Quantification of Soluble Transferrin Receptor: An Important Disease Marker for Iron Deficiency Anemia and Kidney Diseases

Transferrin receptor (TfR) is overexpressed on the surface of many cancer cells due to its vital roles in iron circulation and cellular respiration. Soluble transferrin receptor (sTfR), a truncated extracellular form of TfR in serum, is an important marker of iron deficiency anemia (IDA) and bone marrow failure in cancer patients. More recently, sTfR level in urine has been related to a specific kidney disease of Henoch-Schönlein purpura nephritis (HSPN). Despite the universal significance of sTfR, there is still a lack of a simple and sensitive method for the quantification of sTfR. Furthermore, it is desirable to have a probe that can detect both TfR and sTfR for further comparison study. In this work, we developed a water-soluble AIE-peptide conjugate with aggregation-induced emission (AIE) characteristics. Taking advantage of the negligible emission from molecularly dissolved tetraphenylethene (TPE), probe TPE-2T7 was used for the light-up detection of sTfR. The probe itself is nonemissive in aqueous solution, but it turns on its fluorescence upon interaction with sTfR to yield a detection limit of 0.27 μg/mL, which is much lower than the sTfR level in IDA patients. Furthermore, a proof-of-concept experiment validates the potential of the probe for diagnosis of HSPN by urine test.

Dual modal ultra-bright nanodots with aggregation-induced emission and gadolinium-chelation for vascular integrity and leakage detection

The study of blood brain barrier (BBB) functions is important for neurological disorder research. However, the lack of suitable tools and methods has hampered the progress of this field. Herein, we present a hybrid nanodot strategy, termed AIE-Gd dots, comprising of a fluorogen with aggregation-induced emission (AIE) characteristics as the core to provide bright and stable fluorescence for optical imaging, and gadolinium (Gd) for accurate quantification of vascular leakage via inductively-coupled plasma mass spectrometry (ICP-MS). In this report, we demonstrate that AIE-Gd dots enable direct visualization of brain vascular networks under resting condition, and that they form localized punctate aggregates and accumulate in the brain tissue during experimental cerebral malaria, indicative of hemorrhage and BBB malfunction. With its superior detection sensitivity and multimodality, we hereby propose that AIE-Gd dots can serve as a better alternative to Evans blue for visualization and quantification of changes in brain barrier functions.

Ultrasmall Conjugated Polymer Nanoparticles with High Specificity for Targeted Cancer Cell Imaging

Fluorescent and biocompatible organic nanoparticles have attracted great interest in cancer detection and imaging, but the nonspecific cellular uptake has limited the detection specificity and sensitivity. Herein, the authors report the ultrasmall conjugated polymer nanoparticles (CPNs) with bright far-red/near-infrared emission for targeted cancer imaging with high specificity. The sizes of the ultrasmall CPNs are around 6 nm (CPN6), while large CPNs show sizes around 30 nm (CPN30). Moreover, CPN6 exhibits largely improved fluorescence quantum yield (η) of 41% than CPN30 (25%). Benefiting from the ultrasmall size, bare CPN6 shows largely suppressed nonspecific cellular uptake as compared to CPN30, while cyclic arginine-glycine-aspartic acid (cRGD) functionalized CPN6 (cRGD-CPN6) possesses excellent selectivity toward αvβ3 integrin overexpressed MDA-MB-231 cells over other cells in cell mixtures. The faster body clearance of CPN6 over CPN30 indicates its greater potentials as a noninvasive nanoprobe for in vivo and practical applications.

Precise Two-Photon Photodynamic Therapy using an Efficient Photosensitizer with Aggregation-Induced Emission Characteristics

Two-photon photodynamic therapy (PDT) is able to offer precise 3D manipulation of treatment volumes, providing a target level that is unattainable with current therapeutic techniques. The advancement of this technique is greatly hampered by the availability of photosensitizers with large two-photon absorption (TPA) cross section, high reactive-oxygen-species (ROS) generation efficiency, and bright two-photon fluorescence. Here, an effective photosensitizer with aggregation-induced emission (AIE) characteristics is synthesized, characterized, and encapsulated into an amphiphilic block copolymer to form organic dots for two-photon PDT applications. The AIE dots possess large TPA cross section, high ROS generation efficiency, and excellent photostability and biocompatibility, which overcomes the limitations of many conventional two-photon photosensitizers. Outstanding therapeutic performance of the AIE dots in two-photon PDT is demonstrated using in vitro cancer cell ablation and in vivo brain-blood-vessel closure as examples. This shows therapy precision up to 5 µm under two-photon excitation.

Zinc(II)-Tetradentate-Coordinated Probe with Aggregation-Induced Emission Characteristics for Selective Imaging and Photoinactivation of Bacteria

The emergence of drug-resistant bacterial pathogens highlights an urgent need for new therapeutic options. Photodynamic therapy (PDT) has emerged as a potential alternative to antibiotics to kill bacteria, which has been used in clinical settings. PDT employs photosensitizers (PSs), light, and oxygen to kill bacteria by generating highly reactive oxygen species (ROS). PDT can target both external and internal structures of bacteria, which does not really require the PSs to enter bacteria. Therefore, bacteria can hardly develop resistance to PDT. However, most of the PSs reported so far are hydrophobic and tend to form aggregates when they interact with bacteria. The aggregation could cause fluorescence quenching and reduce ROS generation, which generally compromises the effects of both imaging and therapy. In this contribution, we report on a Zn(II)-tetradentate-coordinated red-emissive probe with aggregation-induced emission characterization. The probe could selectively image bacteria over mammalian cells. Moreover, the probe shows potent phototoxicity to both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Bacillus subtilis).

A two-channel responsive fluorescent probe with AIE characteristics and its application for selective imaging of superoxide anions in living cells

A red-to-green two-channel responsive and AIE-active fluorescent probe was developed to selectively detect superoxide anions in living cells.

Multifunctional Conjugated Polymer Nanoparticles for Image-Guided Photodynamic and Photothermal Therapy

A multifunctional theranostic platform based on conjugated polymer nanoparticles (CPNs) with tumor targeting, fluorescence detection, photodynamic therapy (PDT), and photothermal therapy (PTT) is developed for effective cancer imaging and therapy. Two conjugated polymers, poly[9,9-bis(2-(2-(2-methoxyethoxy)ethoxy)-ethyl)fluorenyldivinylene]-alt-4,7-(2,1,3-benzothiadiazole) with bright red emission and photosensitizing ability and poly[(4,4,9,9-tetrakis(4-(octyloxy)phenyl)-4,9-dihydro-s-indacenol-dithiophene-2,7-diyl)-alt-co-4,9-bis(thiophen-2-yl)-6,7-bis(4-(hexyloxy)phenyl)-thiadiazolo-quinoxaline] with strong near-infrared absorption and excellent photothermal conversion ability are co-loaded into one single CPN via encapsulation approach using lipid-polyethylene glycol as the matrix. The obtained co-loaded CPNs show sizes of around 30 nm with a high singlet oxygen quantum yield of 60.4% and an effective photothermal conversion efficiency of 47.6%. The CPN surface is further decorated with anti-HER2 affibody, which bestows the resultant anti-HER2-CPNs superior selectivity toward tumor cells with HER2 overexpression both in vitro and in vivo. Under light irradiation, the PDT and PTT show synergistic therapeutic efficacy, which provides new opportunities for the development of multifunctional biocompatible organic materials in cancer therapy.

Highly efficient photosensitizers with aggregation-induced emission characteristics obtained through precise molecular design

Through precise molecular design, predictable properties including photosensitizing efficacy, tunable absorption and emission wavelengths and aggregation-induced emission characteristics were achieved.

Real-time naked-eye multiplex detection of toxins and bacteria using AIEgens with the assistance of graphene oxide

Toxins and bacteria in water or food pose a threat to human life and could potentially be exploited for bioterrorism. Real-time naked-eye detection of these contaminants is highly desirable to provide a direct and simple analytical method and address the challenges of the existing strategies. Using the detection of ricin and B. subtilis as an example, a naked-eye multiplex detection model is established. In this work, a green fluorogen with aggregation-induced emission (AIE) characteristics was encapsulated in silica nanoshells. The resulting green AIE nanoparticles (NPs) were further functionalized with ricin binding aptamers (RBA), which were used together with graphene oxide (GO) to provide a fluorescence turn-on approach recognizable by naked eye for the specific sensing of ricin. The platform is compatible with a red emissive fluorescent light-up probe (AIE-2Van) for B. subtilis detection. The success of the multiplex is validated by different colours, that is, green for ricin and red for B. subtilis, which are clearly recognizable by naked eye in the same solution.

Multifunctional AIEgens for Future Theranostics

The combination of diagnosis and therapeutics into one theranostics system has attracted great interest in life science and biomedical fields. The current theranostic platform largely relies on the integration of multiple materials with different functionalities. The all-in-one approach has the risk of high complicity with reduced reproducibility. Smart design of simple molecules born with multifunctions should represent one of the future directions in theranostics. Fluorogens with aggregation-induced emission (AIEgens) are one type of such smart materials, which have attracted increasing attentions in recent years. In this concept, the key frontier developments of simple AIEgens with multifunctions for imaging and therapy are presented, which include fluorescence-photoacoustic imaging, fluorescence-magnetic resonance imaging, fluorescence image-guided photodynamic therapy, fluorescence image-guided chemotherapy and photoacoustic image-guided photothermal therapy. The smart molecular design to endow each AIEgen with strong capability to simultaneously offer two or more theranostic functions should attract more scientists into this exciting research direction.

A Porphyrin-Based Conjugated Polymer for Highly Efficient In Vitro and In Vivo Photothermal Therapy

Conjugated polymers have been increasingly studied for photothermal therapy (PTT) because of their merits including large absorption coefficient, facile tuning of exciton energy dissipation through nonradiative decay, and good therapeutic efficacy. The high photothermal conversion efficiency (PCE) is the key to realize efficient PTT. Herein, a donor-acceptor (D-A) structured porphyrin-containing conjugated polymer (PorCP) is reported for efficient PTT in vitro and in vivo. The D-A structure introduces intramolecular charge transfer along the backbone, resulting in redshifted Q band, broadened absorption, and increased extinction coefficient as compared to the state-of-art porphyrin-based photothermal reagent. Through nanoencapsulation, the dense packing of a large number of PorCP molecules in a single nanoparticle (NP) leads to favorable nonradiative decay, good photostability, and high extinction coefficient of 4.23 × 10⁴ m^-1 cm^-1 at 800 nm based on porphyrin molar concentration and the highest PCE of 63.8% among conjugated polymer NPs. With the aid of coloaded fluorescent conjugated polymer, the cellular uptake and distribution of the PorCP in vitro can be clearly visualized, which also shows effective photothermal tumor ablation in vitro and in vivo. This research indicates a new design route of conjugated polymer-based photothermal therapeutic materials for potential personalized theranostic nanomedicine.

Elimination of blinding trachoma in China

OBJECTIVE

To present the change in the prevalence of blindness caused by trachoma between 1987 and 2006 by secondary data analysis based on two China National Sample Surveys on Disability (CNSSD).

METHODS

Secondary data analysis was performed on two China National Sample Surveys on Disability (CNSSD), which were national representative household surveys conducted in 1987 and 2006. The prevalence of blindness caused by trachoma was estimated by 10-year age group. In addition, the proportion of various causes of blindness was evaluated. The geographical distribution of blindness caused by trachoma both in 1987 and 2006 was analyzed in order to visualize the hot spots of blinding trachoma in China.

RESULTS

The prevalence of blindness caused by trachoma in China decreased from 51.5/100,000 in 1987 to 17.6/100,000 in 2006. In addition, the proportion of blindness attributed to trachoma also decreased from 10.1% (1987) to 0.9% (2006). Moreover, the prevalence of blindness caused by trachoma was over 200/100,000 in 2.2% of sampled counties in 2006 as compared to 8.6% in 1987. The hot spots of blinding trachoma were shown to be limited to underdeveloped mountain areas in Hubei and Guizhou provinces.

CONCLUSION

Although blinding trachoma is no longer the leading cause of blindness in China since the 2000's, the prevalence of trachoma should still be monitored in some underdeveloped mountain areas. Therefore, health organization must continue to fight against blinding trachoma in underdeveloped areas.