Unveiling the azo-reductase mechanism in Pseudomonas putida for efficient decolorization of textile Reactive dyes: an in-silico study.

The textile industry utilizing affordable azo dyes is a high threat to aquatic life and causes environmental problems due to their toxicity. Biodegradation of azo dyes employing microbes and enzymes has proved to be an efficient method for treating industrial effluent. This study used the novel microbial consortium to decolorize reactive azo dyes (Reactive Red 120; Reactive Black 5 and Reactive Blue 13), and its azo-reductase activity was evaluated. The metagenomic analysis of the consortium identified azo-reductase-producing bacterial species. The molecular docking revealed that PpAzoR from Pseudomonas putida had the highest binding affinities for all the three dyes such as Reactive Black 5 (-9.3 kcal/mol), Reactive Blue 13 (-9.8 kcal/mol) and Reactive Red 120 (-10.7 kcal/mol). The structural rigidity and stability of the docked complex were confirmed through MD simulations evaluated across multiple descriptors from the simulation trajectories. Further, MMPBSA analysis validated the results that binding of the ligands, i.e. dye molecules Reactive Black (RB5), Reactive Blue (RB13) and Reactive Red (RR120) binding with the Azoreductase (PpAzoR) to the screened Azo-dyes was spontaneous. Based on molecular dynamics simulations for 100 ns, RR 120 showed the highest binding affinity (-411.336 ± 46.799 KJ/mol), followed by RB5 (-288.012 ± 33.371 KJ/mol). The dyes (RR120 and RB5) exhibited stable interactions with the target azoreductase (PpAzoR). The present study provides insights that PpAzoR shows the highest decolorization potency, which could be interpreted as a potential dye-degrading protein based on dye-degrading assay findings.Communicated by Ramaswamy H. Sarma.

>90% decolourization observed for all reactive dyes at 72 hAzo reductase-producing bacterial species were identified using metagenomicsPseudomonas putida (PpAzoR) showed maximum binding affinity with all three dyesPositive correlation was established between dye decolourization and in-silico results.

Pentacyclic triterpenoids from the stem of Grewia bracteata Roth demonstrate promising inhibition on tumour cells.

Grewia bracteata Roth stem was investigated for its anticancer potential for the first time. Initially, polarity-guided extracts from three solvents were screened on HeLa, HCT- 116 and MCF-7 tumours cells. The results revealed that ethyl acetate extract (GSE) significantly (p < 0.05) inhibited HeLa, HCT- 116 and MCF-7 cells with respective IC50 values of 30.58, 14.26 and 22.91 µg/mL. GSE inhibited HCT-116 cells with 6- and 21-folds higher than hexane (GSN) and methanol (GSM) extracts, respectively. Hence, column chromatography of GSE was performed and fractionated to 18 fractions. The obtained fractions were further tested on HCT-116 cells. Amongst, the fractions HF6 and DF1 were active with the respective IC50 values of 25.35 and 31.28, µg/mL (p < 0.05). These active fractions were profiled using H1-NMR, C13-NMR and LC-MS/MS analysis, and found the presence of pentacyclic triterpenoids like betulin diacetate and ursolic acid.

Emerging drug delivery systems with traditional routes - A roadmap to chronic inflammatory diseases.

Inflammation is prevalent and inevitable in daily life but can generally be accommodated by the immune systems. However, incapable self-healing and persistent inflammation can progress to chronic inflammation, leading to prevalent or fatal chronic diseases. This review comprehensively covers the topic of emerging drug delivery systems (DDSs) for the treatment of chronic inflammatory diseases (CIDs). First, we introduce the basic biology of the chronic inflammatory process and provide an overview of the main CIDs of the major organs. Next, up-to-date information on various DDSs and the associated strategies for ensuring targeted delivery and stimuli-responsiveness applied to CIDs are discussed extensively. The implementation of traditional routes of drug administration to maximize their therapeutic effects against CIDs is then summarized. Finally, perspectives on future DDSs against CIDs are presented.

Repurposing phytochemicals of Citrullus colocynthis against maltase-glucoamylase using molecular docking, MMGBSA, MD simulation and linear regression to identify potential anti-diabetic compounds.

Diabetes is a common lifestyle disorder found in populations of different age groups. Maltase-glucoamylase catalyses the release of the glucose molecule in the final enzymatic reaction of starch digestion; therefore, inhibition of maltase-glucoamylase is one of the approaches in the development of therapeutics for diabetes. Citrullus colocynthis is commonly recommended in Ayurveda for the treatment of diabetes. The current study applied a structure-based drug design approach to repurpose the phytochemicals of Citrullus colocynthis to identify potential inhibitors for maltase-glucoamylase. 70 phytochemicals of Citrullus colocynthis were screened against maltase-glucoamylase and top 5 molecules 8-p-hydroxybenzylisovitexin, isoorientin, cucurbitacin B, cucurbitacin E, and cucurbitacin I with significant binding energy of -10 kcal/mol, -9.9 kcal/mol, -9.6 kcal/mol, -9.2 kcal/mol, and -7.7 kcal/mol were identified. Furthermore, MMGBSA, pharmacokinetics properties and toxicity prediction were performed on the five identified molecules and top 3 molecules were selected for molecular dynamics (MD) simulation. It was observed from the structural flexibility and dynamic behaviour of the systems that conformational changes were noticed in the complexes as compared to its native state, which suggests that the 3 molecules, namely 8-p-hydroxybenzylisovitexin, isoorientin, and cucurbitacin I of Citrullus colocynthis may act as inhibitors for maltase-glucoamylase.Communicated by Ramaswamy H. Sarma.

Self-assembled hemin-conjugated heparin with dual-enzymatic cascade reaction activities for acute kidney injury.

Nanozymes have prominent catalytic activities with high stability as a substitute for unstable and expensive natural enzymes. However, most nanozymes are metal/inorganic nanomaterials, facing difficulty in clinical translation due to their unproven biosafety and limited biodegradability issues. Hemin, an organometallic porphyrin, was newly found to possess superoxide dismutase (SOD) mimetic activity along with previously known catalase (CAT) mimetic activity. However, hemin has poor bioavailability due to its low water solubility. Therefore, a highly biocompatible and biodegradable organic-based nanozyme system with SOD/CAT mimetic cascade reaction activity was developed by conjugating hemin to heparin (HepH) or chitosan (CS-H). Between them, Hep-H formed a smaller (<50 nm) and more stable self-assembled nanostructure and even possessed much higher and more stable SOD and CAT activities as well as the cascade reaction activity compared to CS-H and free hemin. Hep-H also showed a better cell protection effect against reactive oxygen species (ROS) compared to CS-H and hemin in vitro. Furthermore, Hep-H was selectively delivered to the injured kidney upon intravenous administration at the analysis time point (24 h) and exhibited excellent therapeutic effects on an acute kidney injury model by efficiently removing ROS, reducing inflammation, and minimizing structural and functional damage to the kidney.

Measuring circularity of a manufacturing organization by using sustainable balanced scorecard.

In recent years, circular economy has become a matter of great importance because of its ability to contribute toward economic, environmental, and social aspects of the sustainability. The circular economy approaches help in resource conservation by reducing, reusing, and recycling products/parts/components/materials. On the other hand, Industry 4.0 is coupled with emerging technologies, which support the firms in efficient resource utilization. These innovative technologies can transform the present manufacturing organizations by reducing resource extraction, CO2 emissions, environmental damage, and power consumption and improve it into a more sustainable manufacturing organization. Industry 4.0 along with circular economy concepts greatly improves the circularity performance. However, there is no framework found for measuring the circularity performance of the firm. Therefore, the current study aims to develop a framework for measuring performance in terms of circularity percentage. In this work, graph theory and matrix approach are employed for measuring the performance based on a sustainable balanced scorecard such as internal process, learning and growth, customer and financial with environmental and social perspectives. A case of an Indian barrel manufacturing organization is discussed for the illustration of proposed methodology. Based on "circularity index" of the organization and the maximum possible circularity index, the circularity was found to be 5.10%. It indicates that there is a huge potential for the improvement in the circularity of the organization. An in-depth sensitivity analysis and comparison are also performed to validate the findings. There are very few studies on measuring the circularity. The study developed the approach for measuring circularity, which may be utilized by industrialists and practitioners for improving the circularity.

Nanoreactor for cascade reaction between SOD and CAT and its tissue regeneration effect.

Nanoreactors for scavenging reactive oxygen species (ROS), a major factor in inflammatory diseases, can reduce overproduced ROS, and thus can prevent further progress of the diseases or facilitate the regeneration of damaged inflamed tissues. Herein, we designed a pluronic-based nanocarrier loaded with dual antioxidant enzymes present in vivo (superoxide dismutase (SOD) and catalase (CAT)) as a nanoreactor system for the regeneration of inflammatory tissue. The catalytic activity of each enzyme was enhanced by loading it into the nanocarrier. More importantly, the nanocarrier could enhance the cascade reaction between SOD and CAT, which converts the superoxide anion to oxygen. The synergistic anti-inflammatory effect of the nanoreactor based on the cascade reaction was verified in vitro. Furthermore, in an inflammatory bowel disease (IBD) mouse model, the dual enzyme (SOD/CAT)-loaded nanocarrier could result in significantly enhanced tissue regeneration and notably alleviated inflammation activities upon intravenous administration of them compared to other control groups, including single enzyme (SOD or CAT)-loaded nanocarrier and the free mixture of both enzymes without the nanocarrier. Thus, the efficacy of the nanoreactor for the cascade reaction on tissue regeneration in vivo was proved. Accordingly, the nanoreactor could be applied for tissue regeneration therapy against various inflammatory diseases.

Nanozyme Impregnated Mesenchymal Stem Cells for Hepatic Ischemia-Reperfusion Injury Alleviation.

Mesenchymal stem cell (MSC) based therapy holds great potential for treating numerous diseases owing to their capability to heal injured tissue/organs through paracrine factors secretion and immunomodulation. Despite the high hopes, the low viability of transplanted cells in the injured tissues due to the elevated oxidative stress levels remains the largest obstacle in MSC-based cell therapy. To achieve desired therapeutic efficiency, the survival of the transplanted MSCs in the high oxidative stress environment needs to be ensured. Herein, we proposed the use of a ROS-scavenging nanozyme to protect transplanted MSCs from oxidative stress-mediated apoptosis and thereby improve the therapeutic effect. Prussian blue (PB) nanoparticles as a biocompatible ROS-scavenging nanozyme were incorporated into the MSCs without affecting the stemness and differentiation potential of MSCs. The nanozyme impregnation significantly improved the survival of MSCs in a high oxidative stress condition as well as augmented their paracrine effect and anti-inflammatory properties, resulting in a profound therapeutic effect in vivo in the liver ischemia-reperfusion (I/R) injury animal model. Our results indicated that the nanozyme incorporation into MSCs is a simple but efficient way to improve the therapeutic potential of MSC-based cell therapy.

Eosinophil: a central player in modulating pathological complexity in asthma

Eosinophils are the major inflammatory cells which play a crucial role in the development of allergic and non-allergic asthma phenotypes. Eosinophilic asthma is the most heterogeneous phenotype where activated eosinophils are reported to be significantly associated with asthma severity. Activated eosinophils display an array of cell adhesion molecules that not only act as an activation marker, suitable for assessing severity, but also secrete several tissue factors, cytokines and chemokines which modulate the clinical severity. Eosinophil activations are also strictly associated with activation of other hetero cellular populations like neutrophils, macrophages, mast cells, and platelets which culminate in the onset and progression of abnormal phenotypes such as bronchoconstriction, allergic response, fibrosis instigated by tissue inflammation, epithelial injury, and oxidative stress. During the activated state, eosinophils release several potent toxic signaling molecules such as major basic proteins, eosinophil peroxidase, eosinophil cationic protein (ECP), and lipid mediators, rendering tissue damage and subsequently leading to allergic manifestation. The tissue mediators render a more complex manifestation of a severe phenotype by activating prominent signaling cross-talk. Here, in the current review with the help of search engines of PubMed, Medline, etc, we have tried to shed light and explore some of the potent determinants regulating eosinophil activation leading to asthma phenotype (AU)

Eosinophil: a central player in modulating pathological complexity in asthma.

Eosinophils are the major inflammatory cells which play a crucial role in the development of allergic and non-allergic asthma phenotypes. Eosinophilic asthma is the most heterogeneous phenotype where activated eosinophils are reported to be significantly associated with asthma severity. Activated eosinophils display an array of cell adhesion molecules that not only act as an activation marker, suitable for assessing severity, but also secrete several tissue factors, cytokines and chemokines which modulate the clinical severity. Eosinophil activations are also strictly associated with activation of other hetero cellular populations like neutrophils, macrophages, mast cells, and platelets which culminate in the onset and progression of abnormal phenotypes such as bronchoconstriction, allergic response, fibrosis instigated by tissue inflammation, epithelial injury, and oxidative stress. During the activated state, eosinophils release several potent toxic signaling molecules such as major basic proteins, eosinophil peroxidase, eosinophil cationic protein (ECP), and lipid mediators, rendering tissue damage and subsequently leading to allergic manifestation. The tissue mediators render a more complex manifestation of a severe phenotype by activating prominent signaling cross-talk. Here, in the current review with the help of search engines of PubMed, Medline, etc, we have tried to shed light and explore some of the potent determinants regulating eosinophil activation leading to asthma phenotype.

Antioxidant and anti-inflammatory activities of Prussian blue nanozyme promotes full-thickness skin wound healing.

Excessive reactive oxygen species (ROS) and unresolved inflammations are the major causes of impaired wound healing as they overwhelm the cellular antioxidant system and impede the healing process. In this study, we examined the application of Prussian blue (PB) nanozyme as a novel material for cutaneous wound healing through the alleviation of excessive ROS and inflammation modulation. The PB nanoparticles not only exhibited hydrogen peroxide (H2O2) degradation activity but also showed strong superoxide scavenging ability. PB nanozyme mitigated the intracellular ROS at a high oxidative stress environment, resulting in a pronounced cytoprotective effect. Moreover, PB nanozyme also displayed significant anti-inflammatory activity, as evident from the suppression of inflammatory mediators in the lipopolysaccharide (LPS) induced macrophage cells. Encouraged by the in vitro results, we evaluated the in vivo therapeutic efficacy of PB nanozyme in a full-thickness cutaneous wound model combined with LPS treatment to mimic bacterial infection. The beneficial effects of topically applied PB nanozyme on wound healing and tissue regeneration were evident compared to the control. The periodical administration of a low amount (50 µg × 4) of PB nanoparticles exhibited faster wound closure as well as collagen deposition, maturation, and organization. Moreover, the PB treatment effectively induced the differentiation of keratinocytes, enhanced the neovascularization, and reduced macrophage burden in the entire wound site. Thus, PB nanozyme not only accelerated the healing process in an infection-mimicking cutaneous wound model but also exhibited tissue regeneration characteristics owing to the synergistic effect of ROS-scavenging and anti-inflammatory activities.

A Case Report on Metformin-Associated Lactic Acidosis and Transient Blindness.

Metformin is the first-line treatment for any patient with type 2 diabetes. Metformin-associated lactic acidosis and transient blindness have only been reported in some case series and case reports. It is rare and presents especially in patients with underlying chronic kidney disease (CKD) Stage III and above and on high doses of metformin or with a normal dose of metformin and an associated renal injury. We present here a rare and interesting case of something similar. A 77-year-old woman with a past medical history of type 2 diabetes on metformin, obesity status post gastric bypass, CKD Stage III, presented with complaints of nausea, vomiting, confusion, abdominal pain, diarrhea, decreased urine output, sudden visual loss, and a hypoglycemic episode at home. She was hemodynamically stable. Lab work was suggestive of leukocytosis, hyperkalemia, severe high anion gap metabolic and lactic acidosis, acute-on-chronic kidney injury. Findings on the computed tomography (CT) brain, chest radiograph, and CT abdomen and pelvis could not explain the current scenario. She received Ringer's lactate, a bicarbonate push, and an infusion. Acidosis continued to worsen, she became hypotensive requiring pressor support, and she was immediately taken for hemodialysis. All her symptoms, including vision loss, had improved with a single session of hemodialysis, even before the acidosis had corrected. Work-up for other causes of renal dysfunction came back negative. Metformin was discontinued. She was placed on insulin for her diabetes control.

Catalytic nanographene oxide with hemin for enhanced photodynamic therapy.

Hypoxia is a hallmark of many malignant solid tumors. The inadequate oxygen concentration in the hypoxic regions of a solid tumor impedes the efficiency of photodynamic therapy (PDT) because the generation of reactive oxygen species during the PDT process is directly dependent on the available oxygen. To enhance the therapeutic efficacy of PDT, we have developed a novel catalytic nanoplatform (nGO-hemin-Ce6) by co-encapsulating hemin as a catalase-mimetic nanozyme and chlorin e6 (Ce6) as a photosensitizer into Pluronic-coated nanographene oxide through simple hydrophobic interaction and π-π stacking. The nanosystem showed high cellular uptake in the breast cancer cells but did not show any cytotoxicity in the dark condition. nGO-hemin-Ce6 showed efficient O2 generation capacity in the presence of H2O2, through the catalase-mimetic activity of hemin. In the in vitro cell experiments, only nGO-hemin-Ce6 could show comparable PDT effect in normoxia as well as hypoxia due to the in situ O2 generation capability. Upon intravenous administration, nGO-hemin-Ce6 nanosystem showed high tumor accumulation through passive targeting owing to their small size (~ 50 nm). Within the tumor, hemin generated O2 from the endogenous H2O2 and attenuated hypoxia as evidenced by the reduced expression of HIF-1α, a prominent hypoxia marker. Meanwhile, catalytically generated O2 markedly improved the therapeutic efficiency of PDT in a mouse tumor xenograft model by aiding the light-induced ROS production by Ce6. Compared to a control nanosystem without hemin (nGOCe6), the catalytic nanosystem of nGO-hemin-Ce6 exhibited significantly higher tumor suppression ability.

Improving cancer therapy through the nanomaterials-assisted alleviation of hypoxia.

Hypoxia, resulting from the imbalance between oxygen supply and consumption is a critical component of the tumor microenvironment. It has a paramount impact on cancer growth, metastasis and has long been known as a major obstacle for cancer therapy. However, none of the clinically approved anticancer therapeutics currently available for human use directly tackles this problem. Previous clinical trials of targeting tumor hypoxia with bioreductive prodrugs have failed to demonstrate satisfactory results. Therefore, new ideas are needed to overcome the hypoxia barrier. The method of modulating hypoxia to improve the therapeutic activity is of great interest but remains a considerable challenge. One of the emerging concepts is to supply or generate oxygen at the tumor site to increase the partial oxygen pressure and thereby reverse the hypoxia and its effects. In this review, we present an overview of the recent progress in the development of novel nanomaterials for the alleviation of hypoxic microenvironment. Two main strategies for hypoxia augmentation, i) direct delivery of O2 into the tumor, and ii) in situ O2 generations in the tumor microenvironment through different methods such as catalytic decomposition of endogenous hydrogen peroxide (H2O2) and light-triggered water splitting are discussed in detail. At present, these emerging nanomaterials are in their early phase and expected to grow rapidly in the coming years. Despite the promising start, there are several challenges needed to overcome for successful clinical translation.

Targeted delivery of anti-inflammatory cytokine by nanocarrier reduces atherosclerosis in Apo E-/- mice.

Unresolved inflammation is a hallmark of many deadly diseases including atherosclerosis, a silent pathological condition behind majority of cardiovascular diseases. Yet, anti-inflammatory drugs are not clinically used in the treatment of patients with atherosclerosis. The currently approved treatment regimen against atherosclerosis is mainly focused on lowering the cholesterol/lipid levels in blood and has little to do with controlling inflammation, the underlying cause. Recent preclinical and clinical data suggest that effective alleviation of inflammation in the atherosclerosis plaque could reduce the risk of cardiovascular disease. In this work, we have encapsulated interleukin-10 (IL10), a multipotent anti-inflammatory cytokine into cRGD conjugated pluronic based nano-carriers (NC) for targeted delivery to atherosclerotic plaques. The NC could encapsulate the therapeutic protein with a high loading efficiency in a mild condition and showed sustained release capabilities. The efficacy of cytokine encapsulated NC was analyzed in vitro using the lipopolysaccharide stimulated macrophage cells and in vivo using an established apolipoprotein E-knockout (ApoE-/-) C57BL/6 mouse model. Compared to free IL10, intravenous administration of NC encapsulated IL10 resulted in vastly improved pharmacokinetic profile and profoundly high accumulation of the cytokine in the atherosclerosis lesions. IL10 delivered by NC was bioactive and reduced the production of pro-inflammatory cytokine IL-1ß in the lesion and led to significant regression in the plaque size. These results signify the prospect of nanoparticle based cytokine delivery for preventing atherosclerotic through inflammation modulation in near future.

Magnetoliposomes with size controllable insertion of magnetic nanoparticles for efficient targeting of cancer cells.

Liposomes with embedded magnetic nanoparticles (magnetoliposomes; MLs) are promising nano-platforms for various biomedical applications. The magnetic behavior of MLs depends on the size of embedded magnetic nanoparticles (MNPs); in general, larger MNPs are more advantageous (e.g. increased magnetic signals). However, the insertion of large MNPs into liposome bilayers is constrained by the thickness of the membrane (∼3.4 nm); thus, the incorporation of larger magnetic nanoparticles (>3.4 nm) into liposomes is a major challenge. We developed a solvent-guided approach for the simple and efficient insertion of large MNPs (6 nm or 15 nm) into the liposomal bilayer. MLs with 6 nm MNPs were used for the magnetic field-guided separation of cancer cells by targeting to human epidermal receptor 2 and folate receptor. We also evaluated the nuclear delivery of oligonucleotides by MLs with a cationic lipid formula. The MLs are expected to be versatile nano-platforms for biomedical applications (e.g. disease diagnosis, therapeutics and cell tracking).

An injectable and physical levan-based hydrogel as a dermal filler for soft tissue augmentation.

The use of injectable materials as a biofiller for soft tissue augmentation has been increasing worldwide. Levan is a biocompatible and inexpensive polysaccharide with great potential in biomaterial applications, but it has not been extensively studied. In this study, we evaluated the potential of levan as a new material for dermal fillers and prepared an injectable and physical levan-based hydrogel by combining levan with Pluronic and carboxymethyl cellulose (CMC). A sol state was prepared by mixing the polymers in a specific ratio at 4 °C for 2 days and the hydrogel was formed by increasing the temperature to 37 °C. The elastic modulus of the levan hydrogel was higher than that of a hyaluronic acid (HA)-based hydrogel. The SEM images of the levan hydrogel showed an interconnected porous structure, similar to the HA hydrogel. Levan showed non-cytotoxicity, enhanced cell proliferation, and higher amount of collagen synthesis in human dermal fibroblast cells compared to HA. The injected levan hydrogel was biocompatible and stable over 2 weeks in vivo, longer than the Pluronic F127 hydrogel or HA hydrogel. Also, the levan hydrogel showed a higher amount of collagen production than the HA hydrogel in vivo. More importantly, the levan hydrogel showed enhanced anti-wrinkle efficacy compared to the HA hydrogel in a wrinkle model mouse. Thus, the levan hydrogel with injectability, biocompatibility, and an anti-wrinkle effect has high potential as an alternative to existing commercial dermal fillers.

Improved near infrared-mediated hydrogel formation using diacrylated Pluronic F127-coated upconversion nanoparticles.

In situ hydrogel synthesis based on photopolymerization has been recognized as a promising strategy that can be used for tissue augmentation. In this study, we developed an efficient in situ gelation method to prepare bulk hydrogels via near infrared (NIR)-mediated photopolymerization using acrylated polyethylene glycol and diacrylated Pluronic F127-coated upconversion nanoparticles (UCNPs). In our system, upon 980-nm laser irradiation, UCNPs transmit visible light, which triggers the activation of eosin Y to initiate polymerization. We found that the UCNPs coated with diacrylated Pluronic F127 can enhance the photopolymerization efficiency and thus enable the production of bulk hydrogel with requirement of a lower NIR light power compared to that required with the bare UCNPs. This photopolymerization approach will be beneficial to achieve in situ polymerization in vivo for various biomedical applications such as cell/drug delivery and construction of tissue augments.

A novel alendronate functionalized nanoprobe for simple colorimetric detection of cancer-associated hypercalcemia.

The calcium (Ca2+) ion concentration in the blood serum is tightly regulated, and any abnormalities in the level of serum calcium ions are associated with many potentially dangerous diseases. Thus, monitoring of the Ca2+ ion concentration in the blood serum is of fundamental importance. Gold nanoparticle (GNP)-based colorimetric biosensors have enormous potential in clinical diagnostic applications due to their simplicity, versatility, and unique optical properties. In this study, we have developed an alendronate functionalized gold nanoparticle (GNP-ALD) system for the measurement of Ca2+ ion concentration in biological samples. The GNP-ALD system showed higher sensitivity towards the Ca2+ ion compared to adenosine diphosphate (ADP) or adenosine triphosphate (ATP). The strong interaction between the Ca2+ ion and ALD at the GNP/solution interface resulted in significant aggregation of the ALD conjugated GNPs, and induced a color change of the solution from red to blue, which could be visually observed with the naked eye. The interaction between the Ca2+ ion and GNP-ALD was characterized by UV-visible spectroscopy, transmission electron microscopy (TEM) imaging, and dynamic light scattering (DLS) analysis. Under the optimized conditions, the lower limit of Ca2+ ion detection using this method was found to be 25 µM and a linear response range from 25 µM to 300 µM Ca2+ ions was obtained with excellent discrimination against other metal ions. The GNP-ALD nanoprobe could successfully determine the ionized Ca2+ concentration in various serum samples and the results were validated using a commercial calcium assay kit. Moreover, as a practical application, we demonstrated the utility of this nanoprobe for the detection of cancer-associated hypercalcemia in a mouse model.

Comparison of in vivo targeting ability between cRGD and collagen-targeting peptide conjugated nano-carriers for atherosclerosis.

Atherosclerosis plaque is a major cause of cardiovascular diseases across the globe and a silent killer. There are no physical symptoms of the disease in its early stage and current diagnostic techniques cannot detect the small plaques effectively or safely. Plaques formed in blood vessels can cause serious clinical problems such as impaired blood flow or sudden death, regardless of their size. Thus, detecting early stage of plaques is especially more important to effectively reduce the risk of atherosclerosis. Nanoparticle based delivery systems are recognized as a promising option to fight against this disease, and various targeting ligands are typically used to improve their efficiency. So, the choice of appropriate targeting ligand is a crucial factor for optimal targeting efficiency. cRGD peptide and collagen IV targeting peptide, which binds with the αvß3 integrin overexpressed in the neovasculature of the plaque and collagen type IV present in the plaque, respectively, are frequently used for the targeting of nanoparticles. However, at present no study has directly compared these two peptides. Therefore, in this study, we have prepared cRGD or collagen IV targeting (Col IV-tg-) peptide conjugated and iron oxide nanoparticle (IONP) loaded Pluronic based nano-carriers for systemic comparison of their targeting ability towards in vivo atherosclerotic plaque in Apolipoprotein E deficient (Apo E-/-) mouse model. Nano-carriers with similar size, surface charge, and IONP loading content but with different targeting ligands were analyzed through in vitro and in vivo experiments. Near infrared fluorescence imaging and magnetic resonance imaging techniques as well as Prussian blue staining were used to compare the accumulation of different ligand conjugated nano-caariers in the aorta of atherosclerotic mice. Our results indicate that cRGD based targeting is more efficient than Col IV-tg-peptide in the early stage of atherosclerosis.