Colony Stimulating Factor-1 Receptor: An emerging target for neuroinflammation PET imaging and AD therapy.

Although neuroinflammation is a significant pathogenic feature of many neurologic disorders, its precise function in-vivo is still not completely known. PET imaging enables the longitudinal examination, quantification, and tracking of different neuroinflammation biomarkers in living subjects. Particularly, PET imaging of Microglia, specialised dynamic immune cells crucial for maintaining brain homeostasis in central nervous system (CNS), is crucial for staging the neuroinflammation. Colony Stimulating Factor- 1 Receptor (CSF-1R) PET imaging is a novel method for the quantification of neuroinflammation. CSF-1R is mainly expressed on microglia, and neurodegenerative disorders greatly up-regulate its expression. The present review primarily focuses on the development, pros and cons of all the CSF-1R PET tracers reported for neuroinflammation imaging. Apart from neuroinflammation imaging, CSF-1R inhibitors are also reported for the therapy of neurodegenerative diseases such as Alzheimer's disease (AD). AD is a prevalent, advancing, and fatal neurodegenerative condition that have the characteristic feature of persistent neuroinflammation and primarily affects the elderly. The aetiology of AD is profoundly influenced by amyloid-beta (Aß) plaques, intracellular neurofibrillary tangles, and microglial dysfunction. Increasing evidence suggests that CSF-1R inhibitors (CSF-1Ri) can be helpful in preclinical models of neurodegenerative diseases. This review article also summarises the most recent developments of CSF-1Ri-based therapy for AD.

In silico Identification of MHC Displayed Tumor Associated Peptides in Ovarian Cancer for Multi-Epitope Vaccine Construct.

BACKGROUND: Recognizing the potential of the immune system, immunotherapies have brought about a revolution in the treatment of cancer. Low tumour mutational burden and strong immunosuppression in the peritoneal tumor microenvironment (TME) lead to poor outcomes of immune checkpoint inhibition (ICI) and CART cell therapy in ovarian cancer. Alternative immunotherapeutic strategies are of utmost importance to achieve sound clinical success. INTRODUCTION: The development of peptide vaccines based on tumor-associated antigens (TAAs) for ovarian cancer cells can be a potential target to provoke an anti-tumor immune response and subsequent clearance of tumour cells. The purpose of this in-silico study was to find potential epitopes for a multi-epitope vaccine construct using the immunopeptidomics landscape of ovarian carcinoma. METHODS: The four TAAs (MUC16, IDO1, FOLR1, and DDX5) were selected as potential epitopes for B-cells, helper T-lymphocytes (HTLs), and cytotoxic T-lymphocytes (CTLs) predicted on the basis of antigenic, allergenic, and toxic properties. These epitopes were combined with suitable linkers and an adjuvant to form a multi-epitope construct. RESULTS: Four HTLs, 13 CTLs, and 6 potential B-cell epitopes were predicted from the TAAs. The designed multi-epitope construct was potentially immunogenic, non-toxic, and nonallergenic. Physicochemical properties and higher-order structural analyses of the final construct revealed a potential vaccine candidate. CONCLUSION: The designed vaccine construct has the potential to trigger both humoral and cellular immune responses and may be employed as a therapeutic immunization candidate for ovarian malignancies. However, further in vitro and animal experimentation is required to establish the efficacy of the vaccine candidate.

Virus-like nanoparticles as enzyme carriers for Enzyme Replacement Therapy (ERT).

Enzyme replacement therapy (ERT) has been used to treat a few of the many existing diseases which are originated from the lack of, or low enzymatic activity. Exogenous enzymes are administered to contend with the enzymatic activity deficiency. Enzymatic nanoreactors based on the enzyme encapsulation inside of virus-like particles (VLPs) appear as an interesting alternative for ERT. VLPs are excellent delivery vehicles for therapeutic enzymes as they are biodegradable, uniformly organized, and porous nanostructures that transport and could protect the biocatalyst from the external environment without much affecting the bioactivity. Consequently, significant efforts have been made in the production processes of virus-based enzymatic nanoreactors and their functionalization, which are critically reviewed. The use of virus-based enzymatic nanoreactors for the treatment of lysosomal storage diseases such as Gaucher, Fabry, and Pompe diseases, as well as potential therapies for galactosemia, and Hurler and Hunter syndromes are discussed.

Targeted Enzymatic VLP-Nanoreactors with ß-Glucocerebrosidase Activity as Potential Enzyme Replacement Therapy for Gaucher's Disease.

Gaucher disease is a genetic disorder and the most common lysosomal disease caused by the deficiency of enzyme ß-glucocerebrosidase (GCase). Although enzyme replacement therapy (ERT) is successfully applied using mannose-exposed conjugated glucocerebrosidase, the lower stability of the enzyme in blood demands periodic intravenous administration that adds to the high cost of treatment. In this work, the enzyme ß-glucocerebrosidase was encapsulated inside virus-like nanoparticles (VLPs) from brome mosaic virus (BMV), and their surface was functionalized with mannose groups for targeting to macrophages. The VLP nanoreactors showed significant GCase catalytic activity. Moreover, the Michaelis-Menten constants for the free GCase enzyme (KM =0.29 mM) and the functionalized nanoreactors (KM =0.32 mM) were similar even after chemical modification. Importantly, the stability of enzymes under physiological conditions (pH 7.4, 37 °C) was enhanced by ≈11-fold after encapsulation; this is beneficial for obtaining a higher blood circulation half-life, which may decrease the cost of therapy by reducing the requirement of multiple intravenous injections. Finally, the mannose receptor targeted enzymatic nanoreactors showed enhanced internalization into macrophage cells. Thus, the catalytic activity and cell targeting suggest the potential of these nanoreactors in ERT of Gaucher's disease.

Bio-Evaluation of 99mTc-Labeled Homodimeric Chalcone Derivative as Amyloid-ß-Targeting Probe.

Chalcone derivatives have been successfully utilized for a range of biological applications and can cross the blood-brain barrier easily. ß-amyloid-specific bis-chalcone derivative, 6,9-bis(carboxymethyl)-14-(4-[(E)-3-(4-(dimethylamino)phenyl)acryloyl]phenoxy)-3-(2-[(2-(4-[(E)-3-(4-(dimethylamino)phenyl)acryloyl]phenoxy)ethyl)amino]-2-oxoethyl)-11-oxo-3,6,9,12-tetraazatetradecanoic acid, DT(Ch)2, was analyzed using molecular modeling to explain the binding modes of the ligand with amyloid fibril and monomer followed by 99mTc-complexation in 95% yield and 98.7% efficiency. High-binding specificity of the radiocomplex was established following in vitro evaluation against 100-fold excess of DT(Ch)2. 99mTc-DT(Ch)2 exhibited <3% trans-complexation in human serum after 24 h, indicating high stability. A fast clearance rate in pharmacokinetics studies displayed a biphasic pattern with t 1/2(F) = 30 min ± 0.09 and t 1/2(S) = 4 h 20 min ± 0.06. In vivo single-photon emission computed tomography (SPECT) imaging in rabbits reiterated the pharmacokinetics data with initially high brain uptake followed by rapid washout. Biodistribution studies confirmed the initial brain uptake as 1.16 ± 0.02% ID/g after 2 min and the brain2min/brain30min ratio was 3.74. Radioactivity distribution in the brain was >40% in the cingulate cortex followed by >25% in the hippocampus, a distribution pattern aligned to Alzheimer's affected brain regions. Radiocomplex also displayed rapid plasma clearance followed by hepatobolic and renal modes of excretion.

Progress on carbon dots and hydroxyapatite based biocompatible luminescent nanomaterials for cancer theranostics.

Despite the significant advancement in cancer diagnosis and therapy, a huge burden remains. Consequently, much research has been diverted on the development of multifunctional nanomaterials for improvement in conventional diagnosis and therapy. Luminescent nanomaterials offer a versatile platform for the development of such materials as their intrinsic photoluminescence (PL) property offers convergence of diagnosis as well as therapy at the same time. However, the clinical translation of nanomaterials faces various challenges, including biocompatibility and cost-effective scale up production. Thus, luminescent materials with facile synthesis approach along with intrinsic biocompatibility and anticancerous activity hold significant importance. As a result, carbon dots (CDs) and nanohydroxyapatite (nHA) have attracted much attention for the development of optical imaging probes. CDs are the newest members of the carbonaceous nanomaterials family that possess intrinsic luminescent and therapeutic properties, making them a promising candidate for cancer theranostic. Additionally, nHA is an excellent bioactive material due to its compositional similarity to the human bone matrix. The nHA crystal can efficiently host rare-earth elements to attain luminescent property, which can further be implemented for cancer theranostic applications. Herein, the development of CDs and nHA based nanomaterials as multifunctional agents for cancer has been briefly discussed. The emphasis has been given to different synthesis strategies leading to different morphologies and tunable PL spectra, followed by their diverse applications as biocompatible theranostic agents. Finally, the review has been summarized with the current challenges and future perspectives.

68Ga-Labeled bismacrocyclic methylene phosphonate as potential bone seeking PET radiopharmaceutical.

Phosphonates-based agents are well-known bone-seeking radiopharmaceuticals with application in detection and therapy. With higher sensitivity and resolution offered by Positron Emission Tomography (PET), tracers based on this technique are gaining huge attention. 68Ga-based generator and radiotracers render independence from the on-site cyclotron. We report the development of 68Ga-labeled DOTA-based bismacrocyclic phosphonate derivative, for bone PET imaging. The synthesis and characterization of 68Ga- DO3P-AME-DO3P was carried out in > 95% purity. The radiotracer displayed high stability and low binding affinity (<3%) to blood serum. High in vitro binding affinity were observed for synthetic hydroxyapatite, SAOS-2, osteoclast and osteoblast cells. In vivo pharmacokinetics revealed fast washout with biphasic release pattern. The deposition of radiotracer in osseous tissues was high (Bone/Muscle ratio:18), as studied from the biodistribution studies. In vivo PET/CT and biodistribution analyses revealed the ability of 68Ga-DO3P-AME-DO3P to target and accumulate in bone, thus displaying its potential as a PET bone imaging agent.

Camouflaged, activatable and therapeutic tandem bionanoreactors for breast cancer theranosis.

The one-pot cascade reaction of naturally occurring enzymes is exciting for highly selective complex reaction and biodegradable approaches. Tamoxifen is the main drug against breast cancer for decades and induces an anticancerous effect upon metabolic activation by cytochrome P450 (CYP450). Herein, bi-enzymatic nanoreactors (NRs) are developed as a multimodality platform for smart action against breast tumors. CYPBM3 of Bacillus magaterium (CYP) is co-confined with glucose oxidase (GOx) where GOx produces H2O2 in the presence of glucose that elicits the CYP-mediated transformation of tamoxifen. The scintillating and mesoporous LaF3:Tb as nanocarrier showed advantages like a wide range of pore size and positive surface charge for efficient loading of enzyme couple, while the smallest pores were available for substrate/product diffusion. The obtained NRs were camouflaged with human serum albumin (HSA) to overcome premature enzyme leaching and provide active stealth properties. The nanocomposite was characterized for physicochemical properties and glucose-mediated sequential catalysis. The in vitro studies demonstrated the cell internalization of NRs in both ER+ and triple-negative breast cancer cell lines and showed significant cytotoxicity. The developed NRs not only improve the outcomes of endocrine therapy in ER+ cells but also synergistically act with oxidation therapy for enhanced therapeutic effect. Importantly, inhibition of triple-negative cells was also achieved. Thus, the development of the new multimodal nanomedicine of the present work should afford new tools towards the theranosis of breast cancer with minimized adverse effects.

Bi-enzymatic virus-like bionanoreactors for the transformation of endocrine disruptor compounds.

Endocrine disruptor compounds (EDCs) are pollutants able to alter both hormone synthesis and their regulation in animals and humans, thus, EDCs represent a risk for public health and for the environment. Cytochrome P450 enzymes (CYPs) are involved in the detoxification of a wide range of compounds, and it has been established that these enzymes produce the initial biotransformation of many EDCs. In this work, a bionanoreactor based on the encapsulation of an enhanced peroxygenase CYPBM321B3 inside the capsid of bacteriophage P22 virus-like particles (VLPs) was designed and characterized. VLPs were functionalized with glucose oxidase to generate in situ hydrogen peroxide necessary to activate the transformation of bisphenol A, nonylphenol, 17ß-estradiol, triclosan, and resorcinol. Catalytic parameters, as well as the chemical nature of reaction products are presented. The enzymatic nanoreactors showed specific activities varying from 0.175 to 0.456 min-1 in the transformation of these EDCs, which are equivalent to 22-77% of the activity obtained with free CYP. The capacity to transform structurally diverse compounds, easy production and glucose fueled catalytic activity make these enzymatic nanoreactors an interesting platform for enzyme delivery in the biomedical field.

Dual-photosensitizer coupled nanoscintillator capable of producing type I and type II ROS for next generation photodynamic therapy.

The current photodynamic therapy (PDT) is majorly hindered by the shallow penetration depth and oxygen dependency, limiting its application to deep-seated solid hypoxic tumors. Thus, it is meaningful to develop efficient X-ray mediated PDT system capable of generating reactive oxygen species (ROS) under both the normoxic and hypoxic conditions. Herein, we report the synthesis and characterization of nanocomposite, YAG:Pr@ZnO@PpIX with an amalgamation of UV-emitting Y2.99Pr0.01Al5O12 (YAG:Pr) nanoscintillator, and zinc oxide (ZnO) and protoporphyrin IX (PpIX) as photosensitizers. YAG:Pr surface was coated with a ZnO layer (∼10 nm) by atomic layer deposition, and then PpIX was covalently conjugated via a linker to give YAG:Pr@ZnO@PpIX. The photo- and cathodoluminescence analyses gave the evidences of efficient energy transfer from YAG:Pr to ZnO at ∼320 nm, and YAG:Pr@ZnO to PpIX at Soret region (350-450 nm). The nanohybrid was able to produce both, Type I and Type II ROS upon direct and indirect photoactivation with UV365nm and UV290nm, respectively. In vitro cytotoxicity of non-activated YAG:Pr@ZnO@PpIX in mouse melanoma cells revealed low toxicity, which significantly enhanced upon photoactivation with UV365nm indicating the photokilling property of the nanohybrid. Overall, our preliminary studies successfully demonstrate the potential of YAG:Pr@ZnO@PpIX to overcome the limited penetration and oxygen-dependency of traditional PDT.

Intraocular Pressure Changes during Laparoscopic Surgery in Trendelenburg Position in Patients Anesthetized with Propofol-based Total Intravenous Anesthesia Compared to Sevoflurane Anesthesia: A Comparative Study.

BACKGROUND: Intraocular pressure (IOP) is increased during laparoscopic surgery with Trendelenburg position and may contribute to deleterious effects on optic nerve in susceptible patients. AIMS: The primary objective of this study is to compare the effects of propofol-based total intravenous anesthesia (TIVA) with those of sevoflurane anesthesia on IOP in patients undergoing lower abdominal laparoscopic surgery in Trendelenburg position. Secondary objectives are to compare hemodynamic changes, mean arterial pressure (MAP), end-tidal CO2, and peak inspiratory pressure changes. MATERIALS AND METHODS: Sixty patients with physical status American Society of Anesthesiologists classes I and II were randomly allocated in two groups: Group A (propofol) and Group B (sevoflurane). IOP along with other parameters was measured at seven points including baseline (T0), 5 min after induction (T1), 5 min after CO2 pneumoperitoneum in supine position (T2), 30 min after CO2 pneumoperitoneum with Trendelenburg position (T3), 5 min after returning to supine position (T4), 5 min after CO2 desufflation (T5), and 5 min after extubation (T6). RESULTS: The change in IOP was different between the two groups. Maximum rise in IOP was seen at T3, and mean ± standard deviation IOP was 15.5 ± 0.9 mmHg and 19.8 ± 1.2 mmHg in Group A and Group B, respectively (P < 0.01). In Group A (propofol), IOP remained almost equal to the baseline value at T3 and the IOP difference was 0.3 ± 0.9 mmHg less than baseline (statistically insignificant, P > 0.05), while in Group B (sevoflurane), IOP increased significantly at T3 and the difference was 4.0 ± 1.2 mmHg (P < 0.001). The IOP was significantly greater (P < 0.01) from T2 to T6 in sevoflurane group than propofol group. CONCLUSION: Propofol-based TIVA is more effective than inhalational anesthesia with sevoflurane in attenuating the increase in IOP during laparoscopic surgery requiring CO2 pneumoperitoneum with Trendelenburg position.

Chalcone Based Homodimeric PET Agent, 11C-(Chal)2DEA-Me, for Beta Amyloid Imaging: Synthesis and Bioevaluation.

Homodimeric chalcone based 11C-PET radiotracer, 11C-(Chal)2DEA-Me, was synthesized, and binding affinity toward beta amyloid (Aß) was evaluated. The computational studies revealed multiple binding of the tracer at the recognition sites of Aß fibrils. The bivalent ligand 11C-(Chal)2DEA-Me displayed higher binding affinity compared to the corresponding monomer, 11C-Chal-Me, and classical Aß agents. The radiolabeling yield with carbon-11 was 40-55% (decay corrected) with specific activity of 65-90 GBq/µmol. A significant ( p < 0.0001) improvement in the binding affinity of 11C-(Chal)2DEA-Me with synthetic Aß42 aggregates over the monomer, 11C-Chal-Me, demonstrates the utility of the bivalent approach. The PET imaging and biodistribution data displayed suitable brain pharmacokinetics of both ligands with higher brain uptake in the case of the bivalent ligand. Metabolite analysis of healthy ddY mouse brain homogenates exhibited high stability of the radiotracers in the brain with >93% intact tracer at 30 min post injection. Both chalcone derivatives were fluorescent in nature and demonstrated significant changes in the emission properties after binding with Aß42. The preliminary analysis indicates high potential of 11C-(Chal)2DEA-Me as in vivo Aß42 imaging tracer and highlights the significance of the bivalent approach to achieve a higher biological response for detection of early stages of amyloidosis.

Multifunctionalized biocatalytic P22 nanoreactor for combinatory treatment of ER+ breast cancer.

BACKGROUND: Tamoxifen is the standard endocrine therapy for breast cancers, which require metabolic activation by cytochrome P450 enzymes (CYP). However, the lower and variable concentrations of CYP activity at the tumor remain major bottlenecks for the efficient treatment, causing severe side-effects. Combination nanotherapy has gained much recent attention for cancer treatment as it reduces the drug-associated toxicity without affecting the therapeutic response. RESULTS: Here we show the modular design of P22 bacteriophage virus-like particles for nanoscale integration of virus-driven enzyme prodrug therapy and photodynamic therapy. These virus capsids carrying CYP activity at the core are decorated with photosensitizer and targeting moiety at the surface for effective combinatory treatment. The estradiol-functionalized nanoparticles are recognized and internalized into ER+ breast tumor cells increasing the intracellular CYP activity and showing the ability to produce reactive oxygen species (ROS) upon UV365 nm irradiation. The generated ROS in synergy with enzymatic activity drastically enhanced the tamoxifen sensitivity in vitro, strongly inhibiting tumor cells. CONCLUSIONS: This work clearly demonstrated that the targeted combinatory treatment using multifunctional biocatalytic P22 represents the effective nanotherapeutics for ER+ breast cancer.

Development of a functionalized UV-emitting nanocomposite for the treatment of cancer using indirect photodynamic therapy.

BACKGROUND: Photodynamic therapy is a promising cancer therapy modality but its application for deep-seated tumor is mainly hindered by the shallow penetration of visible light. X-ray-mediated photodynamic therapy (PDT) has gained a major attention owing to the limitless penetration of X-rays. However, substantial outcomes have still not been achieved due to the low luminescence efficiency of scintillating nanoparticles and weak energy transfer to the photosensitizer. The present work describes the development of Y2.99Pr0.01Al5O12-based (YP) mesoporous silica coated nanoparticles, multifunctionalized with protoporphyrin IX (PpIX) and folic acid (YPMS@PpIX@FA) for potential application in targeted deep PDT. RESULTS: A YP nanophosphor core was synthesized using the sol-gel method to be used as X-ray energy transducer and was then covered with a mesoporous silica layer. The luminescence analysis indicated a good spectral overlap between the PpIX and nanoscintillator at the Soret as well as Q-band region. The comparison of the emission spectra with or without PpIX showed signs of energy transfer, a prerequisite for deep PDT. In vitro studies showed the preferential uptake of the nanocomposite in cancer cells expressing the folate receptorFolr1, validating the targeting efficiency. Direct activation of conjugated PpIX with UVA in vitro induced ROS production causing breast and prostate cancer cell death indicating that the PpIX retained its activity after conjugation to the nanocomposite. The in vivo toxicity analysis showed the good biocompatibility and non-immunogenic response of YPMS@PpIX@FA. CONCLUSION: Our results indicate that YPMS@PpIX@FA nanocomposites are promising candidates for X-ray-mediated PDT of deep-seated tumors. The design of these nanoparticles allows the functionalization with exchangeable targeting ligands thus offering versatility, in order to target various cancer cells, expressing different molecular targets on their surface.

Comparison of i-gel™ and Laryngeal Mask Airway Supreme™ in Different Head and Neck Positions in Spontaneously Breathing Pediatric Population.

BACKGROUND: Although the advantages of ventilation with i-gel™ and laryngeal mask airway Supreme (LMA-Supreme™) has been well documented, they are still under debate for surgeries requiring flexion and extension of neck such as thyroid surgery, tonsillectomy, and neck exploration. Hence, we conducted a study to demonstrate the effect of neck flexion and extension in spontaneously breathing anesthetized pediatric patients utilizing i-gel™ and LMA-Supreme™. METHODS: A prospective, randomized comparative study was conducted on sixty children, thirty each in i-gel™ and LMA-Supreme™ group. Oropharyngeal leak pressure (OPLP), fiberoptic view of vocal cords, and exhaled tidal volume were evaluated in neutral, flexion, and extension neck positions in spontaneously breathing children. RESULTS: OPLP for i-gel™ was found to be significantly higher in flexion (29.00 ± 1.95 cmH2O, P < 0.001) and lower in extension (21.07 ± 2.08 cmH2O, P < 0.001) as compared to neutral (24.67 ± 2.08 cmH2O). Similar results were observed for LMA-Supreme™ which showed significantly higher OPLP in flexion (24.73 ± 2.26, P < 0.001 respectively) and lower in extension (18.67 ± 1.42 cmH2O, P < 0.001) as compared to neutral (20.87 ± 1.80 cmH2O). Worsening of fiberoptic view occurs for i-gel™ and LMA-Supreme™ in flexion (10/12/5/3/0 and 11/14/2/2/1, P < 0.05) as compared to neutral position (17/10/2/1/0 and 15/12/1/1/1), respectively. Significant change did not occur in extension. Ventilation worsening occurred in flexion as compared to neutral position evidenced by significant decrease in exhaled tidal volume (92.90 ± 11.42 and 94.13 ± 7.75 ml, P < 0.05) as compared to neutral (100.23 ± 12.31 and 101.50 ± 8.26 ml) for i-gel™ and LMA-Supreme™, respectively. CONCLUSION: Neck flexion caused a significant increase in leak pressure in both i-gel™ and LMA-Supreme™. With deterioration of fiberoptic view and ventilation, both devices should be used cautiously in pediatric patients in extreme flexion.

Perioperative Considerations in a Patient with Hemophilia A: A Case Report and Review of Literature.

Classic hemophilia or hemophilia A is a congenital bleeding diathesis in which the affected individual may present with spontaneous hemorrhage or persistent bleeding even after minor trauma. Knowledge about the disease process, multidisciplinary team approach, and timely management can lead to favorable outcome in these patients. We report management of a child with hemophilia A for suturing of lacerated upper lip mucosa following trauma. A review of literature with recommendations for perioperative management, especially in the setting of emergency surgery, is also provided.

Endothelialization and characterization of titanium dioxide-coated gas-exchange membranes for application in the bioartificial lung.

Fouling on the gas-exchange hollow-fiber membrane (HFM) of extracorporeal membrane oxygenation (ECMO) devices by blood components and pathogens represents the major hurdle to their long-term application in patients with lung deficiency or unstable hemodynamics. Although patients are treated with anticoagulants, deposition of blood proteins onto the membrane surface may still occur after few days, leading to insufficient gas transfer and, consequently, to device failure. The aim of this study was to establish an endothelial cell (EC) monolayer onto the gas-exchange membrane of an ECMO device with a view to developing a hemocompatible bioartificial lung. Poly(4-methyl-1-pentene) (PMP) gas-exchange membranes were coated with titanium dioxide (TiO2), using the pulsed vacuum cathodic arc plasma deposition (PVCAPD) technique, in order to generate a stable interlayer, enabling cell adhesion onto the strongly hydrophobic PMP membrane. The TiO2 coating reduced the oxygen transfer rate (OTR) of the membrane by 22%, and it successfully mediated EC attachment. The adhered ECs formed a confluent monolayer, which retained a non-thrombogenic state and showed cell-to-cell, as well as cell-to-substrate contacts. The established monolayer was able to withstand physiological shear stress and possessed a "self-healing" capacity at areas of induced monolayer disruption. The study demonstrated that the TiO2 coating mediated EC attachment and the establishment of a functional EC monolayer. STATEMENT OF SIGNIFICANCE: Surface endothelialization is considered an effective approach to achieve complete hamocompatibility of blood-contacting devices. Several strategies to enable endothelial cell adhesion onto stents and vascular prostheses have already been described in the literature. However, only few studies investigated the feasibility of establishing an endothelial monolayer onto the gas exchange membrane of ECMO devices, using peptides or proteins that were weakly adsorbed via dip coating techniques. This study demonstrated the effectiveness of an alternative and stable titanium dioxide coating for gas-exchange membranes, which enabled the establishment of a confluent, functional and non-activated endothelial monolayer, while maintaining oxygen permeability.

Bivalent Approach for Homodimeric Estradiol Based Ligand: Synthesis and Evaluation for Targeted Theranosis of ER(+) Breast Carcinomas.

The synthesis of estradiol based bivalent ligand [(EST)2DT] is reported and its potential for targeted imaging and therapy of ER(+) tumors has been evaluated. For the purpose, ethinylestradiol was functionalized with an azidoethylamine moiety via click chemistry. The resultant derivative was reacted in a bivalent mode with DTPA-dianhydride to form the multicoordinate chelating agent, (EST)2DT which displayed capability to bind (99m)Tc. The radiolabeled complex, (99m)Tc-(EST)2DT was obtained in >99% radiochemical purity and 20-48 GBq/µmol of specific activity. RBA assay revealed ∼15% binding with estrogen receptor. Evaluation of ligand on ER(+)-cell line (MCF-7) suggested enhanced and ER-mediated uptake. In vivo assays displayed early tracer accumulation in MCF-7 xenografts with tumor to muscle ratio ∼6 in 2 h and negligible uptakes in nontargeted organs. MTT assay performed on ER(+) and ER(-) cell lines displayed selective inhibition of ER(+) cancer cell growth with IC50 = 14.3 µM which was comparable to tamoxifen. The anticancer activity of the ligand is possibly due to the increase in ERß and suppression of ERα protein levels in gene transcription. The studies reveal the potential of (EST)2DT as diagnostic imaging agent with the additional benefits in therapy.

(68)Ga based probe for Alzheimer's disease: synthesis and preclinical evaluation of homodimeric chalcone in ß-amyloid imaging.

In an attempt to explore use of PET radioisotope, (68)Ga, in the diagnosis of Alzheimer's disease, a metal-based homodimeric ligand exhibiting high affinity towards Aß aggregates was designed by conjugating two chalcone units with the chelating system, diethylenetriaminepentaacetic acid. Bischalcone derivative, 5,8-bis(carboxymethyl)-13-(4-((E)-3-(4-(dimethylamino)phenyl)acryloyl)phenoxy)-2-(2-(2-(4-((E)-3-(4-(dimethylamino)phenyl)acryloyl)phenoxy)ethylamino)-2-oxoethyl)-10-oxo-2,5,8,11-tetraazatridecane-1-carboxylic acid, DT(Ch)2 was synthesized in 95% yield with high purity. It was radiolabelled with (68)Ga under mild conditions with 85.4% efficiency and 9.5-10 MBq nmol(-1) specific activity. An in vitro binding assay on Aß42 aggregates displayed high binding affinity of (68)Ga-DT(Ch)2 and inhibition constant of 4.18 ± 0.62 nM. The fluorescent properties of the ligand with peaks of absorption/emission at 410/540 nm exhibited a blue shift with 5.5-fold increase in emission intensity on binding with Aß aggregates. Blood kinetics of the complex performed on normal rabbit exhibited fast clearance (t1/2(F) = 24 ± 0.08 min; t1/2(S) = 2 h 40 ± 0.04 min). Ex vivo biodistribution analysis demonstrated blood-brain barrier penetration with brain uptake of 1.24 ± 0.31% ID g(-1) at 2 min p.i. and rapid washout with negligible activity (0.36% ID g(-1)) left at 30 min p.i. These preliminary studies reveal that the bivalent approach of synthesis had minimal effect on binding affinity, signifying that the developed (68)Ga-complex, (68)Ga-DT(Ch)2, may offer a new perspective in generator produced PET imaging probes for Alzheimer's disease.