Considering the individual characteristics of positron emission tomography (PET) and optical imaging (OI) in terms of sensitivity, spatial resolution, and tissue penetration, the development of dual imaging agents for bimodal PET/OI imaging is a growing field. A current major breakthrough in this field is the design of monomolecular agent displaying both a radioisotope for PET and a fluorescent dye for OI. We took advantage of the multifunctionalities allowed by a clickable -glycosyl scaffold to gather the different elements.
View Article and Find Full Text PDFTargeting vascular endothelial growth factor receptor (VEFGR) and its co-receptor neuropilin-1 (NRP-1) is an interesting vascular strategy. tLyp-1 is a tumor-homing and penetrating peptide of 7 amino acids (CGNKRTR). It is a truncated form of Lyp-1 (CGNKRTRGC), which is known to target NRP-1 receptor, with high affinity and specificity.
View Article and Find Full Text PDFPhotodynamic therapy (PDT) is a promising technique to treat different kinds of disease especially cancer. PDT requires three elements: molecular oxygen, a photoactivatable molecule called the photosensitizer (PS), and appropriate light. Under illumination, the PSs generate, in the presence of oxygen, the formation of reactive oxygen species including singlet oxygen, toxic, which then destroys the surrounding tissues.
View Article and Find Full Text PDFDue to their very poor prognosis and a fatal outcome, secondary brain tumors are one of the biggest challenges in oncology today. From the point of view of the early diagnosis of these brain micro- and macro-tumors, the sensitivity and specificity of the diagnostic tools constitute an obstacle. Molecular imaging, such as Positron Emission Tomography (PET), is a promising technique but remains limited in the search for cerebral localizations, given the commercially available radiotracers.
View Article and Find Full Text PDFThe design of bifunctional chelating agents (BFCA) allowing straightforward radiometal labelling of biomolecules is a current challenge. We report herein the development of a bifunctional chelating agent based on a DOTA chelator linked to a -glycosyl compound, taking advantage of the robustness and hydrophilicity of this type of carbohydrate derivative. This new BFCA was coupled with success by CuAAC with c(RGDfK) for αβ integrin targeting.
View Article and Find Full Text PDFBackground: Local recurrences of glioblastoma (GBM) after heavy standard treatments remain frequent and lead to a poor prognostic. Major challenges are the infiltrative part of the tumor tissue which is the ultimate cause of recurrence. The therapeutic arsenal faces the difficulty of eradicating this infiltrating part of the tumor tissue while increasing the targeting of tumor and endogenous stromal cells such as angiogenic endothelial cells.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
April 2020
Self-aggregation of hydrophobic porphyrin-based photosensitizers (PSs) in aqueous biological environment decreases their bioavailability and in vivo therapeutic efficacy, which hampers their clinical use in photodynamic therapy (PDT). In the current study, we explore three new supramolecular systems based of hydrophobic PSs (i.e.
View Article and Find Full Text PDFMultidrug resistance (MDR) and the spread of cancer cells (metastasis) are major causes leading to failure of cancer treatment. MDR can develop in two main ways, with differences in their mechanisms for drug resistance, first drug-selected MDR developing after chemotherapeutic treatment, and metastasis-associated MDR acquired by cellular adaptation to microenvironmental changes during metastasis. This study aims to use a nanoparticle-mediated photodynamic therapy (NPs/PDT) approach to overcome both types of MDR.
View Article and Find Full Text PDFThis study describes the employment of gold nanorods (AuNRs), known for their good reputation in hyperthermia-based cancer therapy, in a hybrid combination of photosensitizers (PS) and peptides (PP). We report here, the design and the synthesis of this nanosystem and its application as a vehicle for the selective drug delivery and the efficient photodynamic therapy (PDT). AuNRs were functionalized by polyethylene glycol, phototoxic pyropheophorbide-a (Pyro) PS, and a "KDKPPR" peptide moiety to target neuropilin-1 receptor (NRP-1).
View Article and Find Full Text PDFIn this study, light-sensitive photosensitizers (Chlorin e6, Ce6) were linked to TiO and SiO nanoparticles (NPs) in order to develop new kinds of NP-based drug delivery systems for cancer treatment by PDT. TiO or SiO NPs were modified either by the growth of a polysiloxane layer constituted of two silane reagents ((3-aminopropyl)triethoxysilane (APTES) and tetraethyl orthosilicate (TEOS)) around the core (PEGylated NPs: TiO@4Si-Ce6-PEG, SiO@4Si-Ce6-PEG) or simply modified by APTES alone (APTES-modified NPs: TiO-APTES-Ce6, SiO-APTES-Ce6). Ce6 was covalently attached onto the modified TiO and SiO NPs via an amide bond.
View Article and Find Full Text PDFPolymer-lipid-PEG hybrid nanoparticles were investigated as carriers for the photosensitizer (PS), 5,10,15,20-Tetrakis(4-hydroxy-phenyl)-21H,23H-porphine (pTHPP) for use in photodynamic therapy (PDT). A self-assembled nanoprecipitation technique was used for preparing two types of core polymers poly(d,l-lactide-co-glycolide) (PLGA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with lipid-PEG as stabilizer. The resulting nanoparticles had an average particle size of 88.
View Article and Find Full Text PDFThis article addresses the in silico-in vitro prediction issue of organometallic nanoparticles (NPs)-based radiosensitization enhancement. The goal was to carry out computational experiments to quickly identify efficient nanostructures and then to preferentially select the most promising ones for the subsequent in vivo studies. To this aim, this interdisciplinary article introduces a new theoretical Monte Carlo computational ranking method and tests it using 3 different organometallic NPs in terms of size and composition.
View Article and Find Full Text PDFDriven by a multidisciplinary approach combination (Structure-Based (SB) Three-Dimensional Quantitative Structure-Activity Relationships (3-D QSAR), molecular modeling, organic chemistry and various biological evaluations) here is reported the disclosure of new thienopyrimidines 1-3 as inhibitors of KDR activity and human umbilical vein endothelial cell (HUVEC) proliferation. More specifically, compound 2f represents a new lead compound that inhibits VEGFR-2 and HUVEC at μM concentration. Moreover by the mean of an endothelial cell tube formation in vitro model 2f tartaric acid salt proved to block angiogenesis of HUVEC at μM level.
View Article and Find Full Text PDFOverexpression of EGFR plays a key-role in head and neck squamous cell carcinoma (HNSCC) and justifies the extensive use of cetuximab, a monoclonal anti-EGFR antibody, as well as EGFR-tyrosine kinase inhibitors (EGFR-TKI), which have been reported to inhibit tumor cell growth and the secretion of pro-angiogenic factors by tumor cells, such as VEGF and IL-8. Moreover, vessel normalization in tumors, suggesting a more complex mediation of endothelial cell growth control has also been observed in vivo. The present study was designed to investigate the angiogenic consequences of exposure of HNSCC tumor cell lines to cetuximab and intercellular signaling between tumor and endothelial cells by secretion of pro- and anti-angiogenic mediators in the conditioned media (CM).
View Article and Find Full Text PDFPurpose: Classical immunoadsorbents used for the removal of deleterious molecules in blood such as auto-antibodies are prepared by covalent coupling of antigens onto previously chemically activated supports. Such a chemical treatment may induce a potential toxicity which can be reduced if new immunoadsorbents are prepared by encapsulating erythrocytes-ghosts carrying antigens inside polymeric and porous microparticles.
Materials And Methods: Erythrocyte-ghosts obtained by hemolysis in hypotonic buffer were encapsulated into ethylcellulose microparticles by w/o/w emulsification.
Background: Epinephrine and more recently arginine vasopressin (AVP) alone or in combination have been proposed in patients with anaphylactic shock, but few experimental data exist. The authors investigated the effects of epinephrine only, AVP only, or epinephrine followed by AVP in a model of anaphylactic shock.
Methods: Ovalbumin-sensitized Brown Norway rats were anesthetized, intubated, and shock induced with ovalbumin.
Background: Artificial oxygen carriers such as perfluorocarbon (PFC) emulsions have reached Phase III clinical trials as alternatives to homologous blood, but their rheologic effects have not been characterized. In this study, the rheologic effects of PFC emulsion in the presence of clinically used volume expanders were investigated.
Study Design And Methods: The effects of a new PFC emulsion (small droplet size with narrow size distribution) at two PFC concentrations (4 and 8 g/dL) on plasma and whole-blood viscosity in the presence of human albumin solution (HAS), hydroxyethyl starch (HES), or modified fluid gelatin (MFG) were investigated.
Background: Arginine vasopressin (AVP) and terlipressin were proposed as alternatives to catecholamines in shock states characterized by decreased plasma AVP concentrations. The endogenous plasma AVP profile in anaphylactic shock is unknown. In an ovalbumin-sensitized anesthetized anaphylactic shock rat model, the authors investigated (1) plasma AVP concentrations and (2) the dose versus mean arterial pressure response for exogenous AVP and terlipressin and compared them with those of epinephrine.
View Article and Find Full Text PDFBackground: The pathophysiology of anaphylactic shock during anesthesia is incompletely characterized. It is described as distributive by analogy with septic shock (anaerobic metabolism, high tissue oxygen pressure [Ptio2] values). The Ptio2 profile and its metabolic consequences during anaphylaxis are not known.
View Article and Find Full Text PDF