Publications by authors named "George Dakwar"

Potent adjuvants are highly demanded for most protein and peptides based vaccine candidates in clinical development. Recognition of viral single stranded (ss)RNA by innate toll-like receptors 7/8 in dendritic cells results in a cytokine environment supportive to the establishment of long lasting antibody responses and Th1 oriented T cell immunity. To fully exploit the immunestimulatory properties of ssRNA, it needs to be adequately formulated to ensure its optimal delivery to dendritic cells in the vaccine draining lymph nodes.

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The in vivo stability and biodegradability of nanocarriers crucially determine therapeutic efficacy as well as safety when used for drug delivery. This study aims to evaluate optimized in vitro techniques predictive for in vivo nanocarrier behavior. Polymeric biodegradable nanogels based on hydroxyethyl methacrylamide-oligoglycolates-derivatized poly(hydroxyethyl methacrylamide-co-N-(2-azidoethyl)methacrylamide) and with various degrees of PEGylation and crosslinking densities are prepared.

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Peritoneal carcinomatosis is a severe form of cancer in the abdomen, currently treated with cytoreductive surgery and intravenous chemotherapy. Recently, nebulization has been proposed as a less invasive strategy for the local delivery of chemotherapeutic drugs. Also, RNA interference has been considered as a potential therapeutic approach for treatment of cancer.

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The rising antimicrobial resistance contributes to 25000 annual deaths in Europe. This threat to the public health can only be tackled if novel antimicrobials are developed, combined with a more precise use of the currently available antibiotics through the implementation of fast, specific, diagnostic methods. Nucleic acid mimics (NAMs) that are able to hybridize intracellular bacterial RNA have the potential to become such a new class of antimicrobials and additionally could serve as specific detection probes.

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Guanidine and morpholine functionalized aliphatic polycarbonate polymers are able to deliver efficiently histone deacetylase 5 (HDAC5) siRNA into the cytoplasm of cancer cells in vitro leading to a decrease of cell proliferation were previously developed. To allow these biodegradable and biocompatible polyplex nanoparticles to overcome the extracellular barriers and be effective in vivo after an intravenous injection, polyethylene glycol chains (PEG or PEG) were grafted on the polymer structure. These nanoparticles showed an average size of about 150 nm and a slightly positive ζ-potential with complete siRNA complexation.

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Delivery of small interfering RNA (siRNA) is recently gaining tremendous attention for the treatment of ovarian cancer. The present study investigated the potential of different liposomal formulations composed of (2,3-dioleoyloxy-propyl)-trimethylammonium (DOTAP) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) encapsulating siRNA (hydration method) for their ability to knockdown luciferase (Luc) activity in human ovarian cancer SKOV-3 cells. Fluorescence single particle tracking (fSPT) and fluorescence correlation spectroscopy (FCS) in human-undiluted ascites fluid obtained from a peritoneal carcinomatosis patient revealed that cationic hydra-lipoplexes (HYDRA-LPXs) and HYDRA-LPXs decorated with stable DSPE-PEG (DSPE HYDRA-LPXs) showed high stability during at least 24 h.

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Active drug targeting and controlled release of hydrophilic macromolecular drugs represent crucial points in designing efficient polymeric drug delivery nanoplatforms. In the present work EGFR-targeted polylactide-co-glycolide (PLGA) nanoparticles were made by a blend of two different PLGA-based polymers. The first, GE11-PLGA, in which PLGA was functionalized with GE11, a small peptide and EGFR allosteric ligand, able to give nanoparticles selective targeting features.

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Intraperitoneal (IP) drug delivery represents an attractive strategy for the local treatment of peritoneal carcinomatosis (PC). Over the past decade, a lot of effort has been put both in the academia and clinic in developing IP therapeutic approaches that maximize local efficacy while limiting systemic side effects. Also nanomedicines are under investigation for the treatment of tumors confined to the peritoneal cavity, due to their potential to increase the peritoneal retention and to target drugs to the tumor sites as compared to free drugs.

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Topical vaginal sustained delivery of siRNA presents a significant challenge due to the short residence time of formulations. Therefore, a drug delivery system capable to adhere to the vaginal mucosa is desirable, as it could allow a prolonged delivery and increase the effectiveness of the therapy. The aim of this project is to develop a polymeric solid mucoadhesive system, loaded with lipoplexes, able to be progressively rehydrated by the vaginal fluids to form a hydrogel and to deliver siRNA to vaginal tissues.

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Helicobacter pylori infects more than 50% of the worldwide population. It is mostly found deep in the gastric mucus lining of the stomach, being a major cause of peptic ulcers and gastric adenocarcinoma. To face the increasing resistance of H.

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Small interfering RNA (siRNA) offers a great potential for the treatment of various diseases and disorders. Nevertheless, inefficient in vivo siRNA delivery hampers its translation into the clinic. While numerous successful in vitro siRNA delivery stories exist in reduced-protein conditions, most studies so far overlook the influence of the biological fluids present in the in vivo environment.

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The applicability of small interfering RNA (siRNA) in future therapies depends on the availability of safe and efficient carrier systems. Ideally, siRNA delivery requires a system that is stable in the circulation but upon specific uptake into target cells can rapidly release its cargo into the cytoplasm. Previously, we evaluated a novel generation of carrier systems ("decationized" polyplexes) for DNA delivery, and it was shown that folate targeted decationized polyplexes had an excellent safety profile and showed intracellular triggered release upon cell specific uptake.

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Many polycation-based gene delivery vectors show high transfection in vitro, but their cationic nature generally leads to significant toxicity and poor in vivo performance which significantly hampers their clinical applicability. Unlike conventional polycation-based systems, decationized polyplexes are based on hydrophilic and neutral polymers. They are obtained by a 3-step process: charge-driven condensation followed by disulfide crosslinking stabilization and finally polyplex decationization.

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Intraperitoneal (IP) administration of nano-sized delivery vehicles containing small interfering RNA (siRNA) has recently gained attention as an alternative route for the efficient treatment of peritoneal carcinomatosis. The colloidal stability of nanomatter following IP administration has, however, not been thoroughly investigated yet. Here, enabled by advanced microscopy methods such as single particle tracking and fluorescence correlation spectroscopy, we follow the aggregation and cargo release of nano-scaled systems directly in peritoneal fluids from healthy mice and ascites fluid from a patient diagnosed with peritoneal carcinomatosis.

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Our understanding of protein evolution would greatly benefit from mapping of binding landscapes, i.e., changes in protein-protein binding affinity due to all single mutations.

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Bolaamphiphiles - amphiphilic molecules consisting of two hydrophilic headgroups linked by a hydrophobic chain - form highly stable vesicles consisting of a monolayer membrane that can be used as vehicles to deliver drugs across biological membranes, particularly the blood-brain barrier (BBB). We prepared new vesicles comprising bolaamphiphiles (bolavesicles) that encapsulate iron oxide nanoparticles (IONPs) and investigated their suitability for targeted drug delivery. Bolavesicles displaying different headgroups were studied, and the effect of IONP encapsulation upon membrane interactions and cell uptake were examined.

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In vitro safety assessment of disposable medical devices, including infusion sets, is usually performed using L-929 mouse keratinocytes. However, cells of different origin (endothelial, lymphoid and myeloid cells) are also exposed to infusion sets' extractables during their clinical use. We studied whether the cEND mouse brain endothelial cells can be suitable for in vitro safety assessment of infusion sets.

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Bolaamphiphilic cationic vesicles with acetylcholine (ACh) surface groups were investigated for their ability to deliver a model protein-bovine serum albumin conjugated to fluorescein isothiocyanate (BSA-FITC) across biological barriers in vitro and in vivo. BSA-FITC-loaded vesicles were internalized into cells in culture, including brain endothelial b.End3 cells, at 37 °C, but not at 4 °C, indicating an active uptake process.

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Squamous cell carcinoma of the prostate is a rare tumor, making up 0.5% to 1% of all prostate carcinomas. It is typically described as an aggressive cancer, with a median postdiagnosis survival of 14 months.

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Purpose: To assess the value of quantitative T2 signal intensity (SI) and apparent diffusion coefficient (ADC) to differentiate prostate cancer from post-biopsy hemorrhage, using prostatectomy as the reference.

Materials And Methods: Forty-five men with prostate cancer underwent prostate magnetic resonance imaging (MRI), including axial T1-weighted imaging (T1WI), T2WI, and single-shot echo-planar image (SS EPI) diffusion-weighted imaging. Two observers measured, in consensus, normalized T2 signal intensity (SI) (nT2, relative to muscle T2 SI), ADC, and normalized ADC (nADC, relative to urine ADC) on peripheral zone (PZ) tumors, benign PZ hemorrhage, and non-hemorrhagic benign PZ.

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Laparoscopic partial nephrectomy (LPN) has been underused because of its technical complexity and difficulty. We present a knotless and bolsterless technique that allows simultaneous repair of the pelvicaliceal system and compression of the parenchyma defect using a series of single-pass running sutures. We believe that this technique will simplify reconstruction and aid in popularization of LPN.

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Purpose: To assess the safety and feasibility of performing robot-assisted pediatric urologic surgery with the da Vinci Surgical System (Intuitive Surgical, Inc, Sunnyvale, Calif) based on our experience with a variety of procedures.

Patients And Methods: A retrospective review was performed of 53 robot-assisted pediatric procedures performed in our practice between September 2003 and March 2006. The procedures included 11 renal extirpative surgeries, 10 orchiopexies, 26 dismembered pyeloplasties, 2 uretero-ureterostomies, and 3 bladder surgeries.

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Transrectal ultrasound-guided biopsy of the prostate is the gold standard for the detection of prostate cancer. In its current form, transrectal gray-scale ultrasound is unable to differentiate malignant prostate tissue from benign tissue. The general indications for performing a sonographic guided biopsy of the prostate are an abnormal digital rectal examination or an abnormal prostate-specific antigen (PSA).

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