Bioconjugation of metal-based compounds for targeted biomedical applications: from drug delivery to mass spectrometry imaging

This thesis described the synthesis, carachterization, and application of bioconjugated metal-based compounds. The bioconjugated Pd-based metallocages are non-toxic to healthy tissue cells. Their well defined structure make them ideal tools for targeted delivery of anticancer drug cisplatin. The bioconjugated Ru-based compounds exhibit high photocleavable property which can be used as mass-tag for the targted mass spectrometry imaging of tumor tissue

Heavy metal induced ecophysiological function alterations in the euhalophyte Suaeda salsa

Heavy metal accumulation affects the physiological status of plants. Suaeda salsa L. is used to investigate the toxic effects of cadmium (Cd) and lead (Pb) either alone or mixtures under the static test conditions. Cd-Pb mixture exposure can decrease lignin content and weaken the increase. Mitochondrial calcium content significantly reduced at 30 µM Cd and Pb exposure. Cd-Pb mixture exposure can increase calcium content under the same concentration exposure. Soluble sugar levels noted a significant decrease in Cd, Pb and Cd-Pb mixture exposure. The accumulations of Cd, Pb in S. salsa were significantly increased with exposure time. Soluble protein (SP) in S. salsa at 30 µM concentration treatments decreased with exposure time. Heat shock protein 70 (HSP70) was enhanced lightly along with the increase of added Cd-Pb from 30 to 70 &3181;M and then decreased below the controls which present a synergistic effect. Heat shock protein 60 (HSP60) increased slightly with the increase of Cd-Pb from 30 to 110 µM, and then decreased hereafter and significantly inhibited at 150 ƒÊM (p<0.05). Moreover, Cd-Pb mixture exposure significantly increased the Rubisco activity under lower concentration and presented antagonistic effect. At the same time, the viability percent decreased as increase Cd-Pb concentration exposure (p0.05), it presents a dose-dependent manner. Mitochondrial cells treated with Cd-Pb exposure obviously reduced the reactive oxygen species (ROS) levels in mitochondrial cells.Key words: Suaeda salsa, heavy metal, ecophysiological function

Imaging of protein distribution in tissues using mass spectrometry: An interdisciplinary challenge

The recent development of mass spectrometry imaging (MSI) technology allowed to obtain extremely detailed images of the spatial distribution of proteins in tissue at high spatial resolution reaching cell dimensions, high target specificity and a large dynamic concentration range. This review focusses on the development of two main MSI principles, namely targeted and untargeted detection of protein distribution in tissue samples, with special emphasis on the improvements in analyzed mass range and spatial resolution over the last 10 years. Untargeted MSI of in situ digested proteins with matrix-assisted laser desorption ionization is the most widely used approach, but targeted protein MSI technologies using laser ablation inductively coupled plasma (LA-ICP) and photocleavable mass tag chemical labeling strategies are gaining momentum. Moreover, this review also provides an overview of the effect of sample preparation on image quality and the bioinformatic challenge to identify proteins and quantify their distribution in complex MSI data

Integrated lipids biomarker of the prediabetes and type 2 diabetes mellitus Chinese patients

IntroductionDyslipidemia is a hallmark of T2DM, and as such, analyses of lipid metabolic profiles in affected patients have the potential to permit the development of an integrated lipid metabolite-based biomarker model that can facilitate early patient diagnosis and treatment.MethodsUntargeted and targeted lipidomics approaches were used to analyze serum samples from newly diagnosed 93 Chinese participants in discovery cohort and 440 in validation cohort via UHPLC-MS and UHPLC-MS/MS first. The acid sphingomyelinase protein expression was analyzed by Western blot.Results and DiscussionThrough these analyses, we developed a novel integrated biomarker signature composed of LPC 22:6, PC(16:0/20:4), PE(22:6/16:0), Cer(d18:1/24:0)/SM(d18:1/19:0), Cer(d18:1/24:0)/SM(d18:0/16:0), TG(18:1/18:2/18:2), TG(16:0/16:0/20:3), and TG(18:0/16:0/18:2). The area under the curve (AUC) values for this integrated biomarker signature for prediabetes and T2DM patients were 0.841 (cutoff: 0.565) and 0.894 (cutoff: 0.633), respectively. Furthermore, theresults of western blot analysis of frozen adipose tissue from 3 week (prediabetes) and 12 week (T2DM) Goto–Kakizaki (GK) rats also confirmed that acid sphingomyelinase is responsible for significant disruptions in ceramide and sphingomyelin homeostasis. Network analyses of the biomarkers associated with this biosignature suggested that the most profoundly affected lipid metabolism pathways in the context of diabetes include de novo ceramide synthesis, sphingomyelin metabolism, and additional pathways associated with phosphatidylcholine synthesis. Together, these results offer new biological insights regarding the role of serum lipids in the context of insidious T2DM development, and may offer new avenues for future diagnostic and/or therapeutic research

Functionalization of Ruthenium(II) terpyridine complexes with cyclic RGD peptides to target integrin receptors in cancer cells

The lack of selectivity for cancer cells and the resulting negative impact on healthy tissue is a severe drawback of actual cancer chemotherapy. Tethering of cytotoxic drugs to targeting vectors such as peptides, which recognize receptors overexpressed on the surface of tumor cells, is one possible strategy to overcome such a problem. The pentapeptide cyc(RGDfK) targets the integrin receptor αvβ3, important for tumor growth and metastasis formation. In this work, two terpyridine based Ru(II) complexes were prepared and for the first time conjugated to cyc(RGDfK) via amide bond formation resulting in a monomeric and a dimeric bioconjugate. Both Ru(II) complexes bind strongly and selectively to integrin αvβ3, with the dimeric molecule displaying a 20-fold higher affinity to the receptor than the monomeric one. However, the cytotoxicity of the complexes and related bioconjugates against human A549 and SKOV-3 cell lines is still not sufficient for application as anticancer agents. Nevertheless, considering the high selectivity for integrin receptor αvβ3, the synthesis of Ru-based bioconjugates with cyc(RGDfK) paves a promising way towards the design of effective targeted anticancer agents

Targeted imaging of integrins in cancer tissues using photocleavable Ru(ii) polypyridine complexes as mass-tags

Targeted epitope-based mass spectrometry imaging (MSI) utilizes laser cleavable mass-tags bound to targeting moieties for detecting proteins in tissue sections. Our work constitutes the first proof-of-concept of a novel laser desorption ionization (LDI)-MSI strategy using photocleavable Ru(ii) polypyridine complexes as mass-tags for imaging of integrins avß3 in human cancer tissues

Standardising Training of Nurses in an Evidence-Based Psychosocial Intervention for Perinatal Depression: Randomized Trial of Electronic vs. Face-to-Face Training in China

Background: Rates of perinatal depression in China are high. The Thinking Healthy Programme is a WHO-endorsed, evidence-based psychosocial intervention for perinatal depression, requiring five days of face-to-face training by a specialist trainer. Given the paucity of specialist trainers and logistical challenges, standardized training of large numbers of nurses is a major challenge for scaling up. We developed an electronic training programme (e-training) which eliminates the need for specialist-led, face-to-face training. The aim of this study was to evaluate the effectiveness of the e-training compared to conventional face-to-face training in nursing students. Methods: A single blind, non-inferiority, randomized controlled trial was conducted. One hundred nursing students from two nursing schools were randomly assigned to either e-training or conventional face-to-face training. Results: E-training was not inferior to specialist-led face-to-face training immediately post-training [mean ENhancing Assessment of Common Therapeutic factors (ENACT) score (M) 45.73, standard deviation (SD) 4.03 vs. M 47.08, SD 4.53; mean difference (MD) −1.35, 95% CI; (−3.17, 0.46), p = 0.14]. There was no difference in ENACT scores at three months [M = 42.16, SD 4.85 vs. M = 42.65, SD 4.65; MD = −0.481, 95% CI; (−2.35, 1.39), p = 0.61]. Conclusions: E-training is a promising tool with comparative effectiveness to specialist-led face-to-face training. E-training can be used for training of non-specialists for evidence-based psychosocial interventions at scale and utilized where there is a shortage of specialist trainers, but practice under supervision is necessary to maintain competence. However, continued practice under supervision may be necessary to maintain competence

Building osteogenic microenvironments with a double-network composite hydrogel for bone repair

The critical factor determining the in vivo effect of bone repair materials is the microenvironment, which greatly depends on their abilities to promote vascularization and bone formation. However, implant materials are far from ideal candidates for guiding bone regeneration due to their deficient angiogenic and osteogenic microenvironments. Herein, a double-network composite hydrogel combining vascular endothelial growth factor (VEGF)-mimetic peptide with hydroxyapatite (HA) precursor was developed to build an osteogenic microenvironment for bone repair. The hydrogel was prepared by mixing acrylated β-cyclodextrins and octacalcium phosphate (OCP), an HA precursor, with gelatin solution, followed by ultraviolet photo-crosslinking. To improve the angiogenic potential of the hydrogel, QK, a VEGF-mimicking peptide, was loaded in acrylated β-cyclodextrins. The QK-loaded hydrogel promoted tube formation of human umbilical vein endothelial cells and upregulated the expression of angiogenesis-related genes, such as Flt1 , Kdr , and VEGF , in bone marrow mesenchymal stem cells. Moreover, QK could recruit bone marrow mesenchymal stem cells. Furthermore, OCP in the composite hydrogel could be transformed into HA and release calcium ions facilitating bone regeneration. The double-network composite hydrogel integrated QK and OCP showed obvious osteoinductive activity. The results of animal experiments showed that the composite hydrogel enhanced bone regeneration in skull defects of rats, due to perfect synergistic effects of QK and OCP on vascularized bone regeneration. In summary, improving the angiogenic and osteogenic microenvironments by our double-network composite hydrogel shows promising prospects for bone repair

Prevention of Wogonin on Colorectal Cancer Tumorigenesis by Regulating p53 Nuclear Translocation

The tumor suppressor protein p53 plays an important role in the development and progression of colon cancer, and the subcellular organelle localization directly affects its function. Wogonin (5,7-dihydroxy-8-methoxyflavone), a mono-flavonoid extracted from root of Scutellaria baicalensis Georgi, possesses acceptable toxicity and has been used in colorectal cancer (CRC) chemoprevention in pre-clinical trials by oncologist. However, the underlying anti-colon cancer mechanisms of wogonin are not yet fully understood. In the present study, the effect of wogonin on the initiation and development of colitis-associated cancer through p53 nuclear translocation was explored. AOM-DSS CRC animal model and human CRC HCT-116 cell model were used to evaluate the in vivo and in vitro anti-colon cancer action of wogonin. We observed that wogonin showed a dramaticlly preventive effect on colon cancer. Our results showed that wogonin caused apoptotic cell death in human CRC HCT-116 cell through increased endoplasmic reticulum (ER) stress. Meanwhile, excessive ER stress facilitated the cytoplasmic localization of p53 through increasing phosphor-p53 at S315 and S376 sites, induced caspase-dependent apoptosis and inhibited autophagy. Furthermore, we verified the chemoprevention effect and toxicity of wogonin in vivo by utilizing an AOM-DSS colon cancer animal model. We found that wogonin not only reduced tumor multiplicity, preserved colon length to normal (6.79 ± 0.34 to 7.41 ± 0.56, P < 0.05) but also didn’t induce side effects on various organs. In conclusion, these results explain the anti-tumor effect of wogonin in CRC and suggest wogonin as a potential therapeutic candidate for the therapeutic strategy in CRC treatment