265 research outputs found
Ruthenium(III) complexes entrapped in liposomes with enhanced cytotoxic and anti-metastatic properties
Metal-based anticancer drugs are pivotal in the fight against cancer pathologies. Since 1978 cis-platin was licensed for medical treatment of a wide number of tumor pathologies(1). However its chemiotherapic use is strongly limited by many and severe side effects and acquired tumor resistance. Since these limitations could be overcome by other metal complexes, in the last thirty years ruthenium compounds have been tested showing a remarkable antitumoral and antimetastatic activity associated with a lower toxicity. A hexacoordinate Ru(III) complex (NAMI-A) is currently undergoing advanced clinical evaluation (2).
All data indicate that NAMI-A acts as a pro-drug, but the integrity of ruthenium complexes is essential to store the cytotoxic activity. In this scenario the condition of administration of ruthenium drugs are crucial to exploit their anticancer activity (3). In the last years innovative strategies have been produced to vehicle ruthenium ions in tumor cells like aggregates. This study aims to incorporate the ruthenium complexes in the inner aqueous compartment of liposomes and to test biological properties of two NAMI-A like pyridine derivatives. Specifically, we have investigated the pyridine derivatives of the sodium-compensated analogue of NAMI-A, Na[trans-RuCl4(pyridine)(DMSO)] (NAMI-Pyr) and Na[trans-RuCl4(Pytri)(DMSO)] (NAMI-Pytri).
In thelatter complex the pyridine ligand is functionalized with a sugar moiety so as to increase biocompatibility and the ability to cross the cell membrane. The stability of the complexes was studied and compared in solution at different pH following UV-VIS spectra. Lipid formulations based on Egg PC were prepared adding Cholesterol, DSPE-PEG2000 joining molar ratio 57/38 /5% w/w respectively in MeOH/CHCl3 (50/50 v/v) mixture and hydrated with 0.9% w/w of NaCl.
This composition was selected to reproduce analog supramolecular aggregates in clinical use to vehicle doxorubicin (Doxil). Ruthenium complexes were loaded into liposomes using the passive equilibration loading method. Full drug containing liposomes were structurally characterized by dynamic light scattering (DLS) measurements. Data indicate the formation of stable aggregates with size and shape in the right range for in vivo applications. The amount of encapsulated ruthenium complexes was quantified by means of ICP-AES. Stability and drug release properties of ruthenium containing liposomes were confirmed in buffer. The growth inhibitory effects of both liposomal and free complexes drug were tested on prostate cancer cells (PC3).
Preliminary results show high cytotoxic effect of ruthenium complexes delivered by supramolecular aggregates with respect to free complexes drug
Evaluation of ECHO PS Positioning System in a Porcine Model of Simulated Laparoscopic Ventral Hernia Repair
Purpose. Operative efficiency improvements for laparoscopic ventral hernia repair (LVHR) have focused on reducing operative time while maintaining overall repair efficacy. Our objective was to evaluate procedure time and positioning accuracy of an inflatable mesh positioning device (Echo PS Positioning System), as compared to a standard transfascial suture technique, using a porcine model of simulated LVHR. Methods. The study population consisted of seventeen general surgeons (n = 17) that performed simulated LVHR on seventeen (n = 17) female Yorkshire pigs using two implantation techniques: (1) Ventralight ST Mesh + Echo PS Positioning System (Echo PS) and (2) Ventralight ST Mesh + transfascial sutures (TSs). Procedure time and mesh centering accuracy overtop of a simulated surgical defect were evaluated. Results. Echo PS demonstrated a 38.9% reduction in the overall procedure time, as compared to TS. During mesh preparation and positioning, Echo PS demonstrated a 60.5% reduction in procedure time (P \u3c 0.0001). Although a trend toward improved centering accuracy was observed for Echo PS (16.2%), this was not significantly different than TS. Conclusions. Echo PS demonstrated a significant reduction in overall simulated LVHR procedure time, particularly during mesh preparation/positioning. These operative time savings may translate into reduced operating room costs and improved surgeon/operating room efficiency
In vitro evaluation of antiviral and virucidal activity of a high molecular weight hyaluronic acid.
BACKGROUND: hyaluronic acid (HA), a non-sulphated glycosaminoglycan, is present in synovial fluid, vitreous humour serum and many connective tissues. Pharmaceutical preparations of HA are used in clinical practice for wound healing, joint pain, kerato-conjunctivitis, asthma, mouth care, oesophageal-reflux, and gastritis. Moreover, it is used as a filler to counteract ageing and facial lipoatrophy. Our study aims at investigating the in vitro antiviral activity of a high molecular weight HA.METHODS: the MTT test was used to rule out the potential toxic effects of HA on the different cell lines used in the antiviral assays. The antiviral activity of HA against Coxsackievirus B5, Herpes simplex virus-1, Mumps virus, Adenovirus-5, Influenza Virus A/H1N1, Human Herpesvirus-6, Porcine Parvovirus, Porcine Reproductive and Respiratory Syndrome Virus was assessed by virus yield assays.RESULTS: the most effective inhibition was observed against Coxsackievirus B5, with 3Log reduction of the virus yield at 4mg/ml, and a reduction of 3.5Log and 2Log, at 2mg/ml and 1mg/ml, respectively: the selectivity index was 16. Mumps virus was highly inhibited too showing a reduction of 1.7Log at 1mg/ml and 1Log at 4mg/ml and 2mg/ml (selectivity index = 12). The selectivity index for Influenza Virus was 12 with the highest inhibition (1Log) observed at 4mg/ml. Herpes simplex virus-1 and Porcine Parvovirus were mildly inhibited, whereas no antiviral activity was observed with respect to Adenovirus-5, Human Herpesvirus-6, Porcine Reproductive and Respiratory Syndrome Virus. No HA virucidal activity was ever observed against any of the viruses tested. Kinetic experiments showed that both Coxsackievirus B5 and Herpes simplex virus-1 replication were consistently inhibited, not influenced by the time of HA addition, during the virus replication cycle.CONCLUSIONS: the spectrum of the antiviral activity exhibited by HA against both RNA and DNA viruses, known to have different structures (with or without envelope) and replication strategies, suggests a non specific mechanism of action, probably involving cell membrane-virus interaction steps. The results of the kinetic experiments support this hypothesis
Hemostatic Agents in Hepatobiliary and Pancreas Surgery: A Review of the Literature and Critical Evaluation of a Novel Carrier-Bound Fibrin Sealant (TachoSil)
Background. Despite progress in surgical techniques applied during hepatobiliary and pancreas (HPB) surgery, bleeding and bile leak remain significant contributors to postoperative mortality and morbidity. Topical hemostatics have been developed and utilized across surgical specialties, but data regarding effectiveness remains inconsistent and sparse in HPB surgery. Methods. A comprehensive search for studies and reviews on hemostatics in HPB surgery was performed via an October 2011 query of Medline, EMBASE, and Cochrane Library. In-depth evaluation of a novel carrier-bound fibrin sealant (TachoSil) was also performed. Results. The literature review illustrates multiple attempts have been made at developing different topical hemostatics and sealants to aid in surgical procedures. In HPB surgery, efforts have been directed at decreasing bleeding, biliary leakage, and pancreatic fistula. Conflicting scientific evidence exists regarding the effectiveness of these agents. Critical evaluation of the literature demonstrates TachoSil is a valuable tool in achieving hemostasis, and possibly biliostasis and pancreatic fistula prevention. Conclusion. While progress has been made in topical hemostatics for HPB surgery, an ideal agent has not yet been identified. TachoSil is promising, but larger randomized, controlled clinical trials are required to more fully evaluate its efficacy in reducing bleeding, biliary leakage, and pancreatic fistulas in HPB surgery
Formation of gutingimycin: analytical investigation of trioxacarcin A-mediated alkylation of dsDNA
Formation and fragmentation of recognition complexes between trioxacarcin A and various DNA sequences were examined by temperature-dependent UV and CD spectroscopy, HPLC analysis, and ESI mass spectrometry with regard to reaction conditions, intermediates, products, mechanism, and sequence specificity. Cleavage of the trioxacarcin–DNA complexes provided the natural product gutingimycin by guanine abstraction. The resulting DNA with an abasic site was further cleaved into a DNA fragment with a furanyl unit at the 3′-end and an oligonucleotide with a phosphorylated 5′-end
Evaluation of E CHO
Purpose. Operative efficiency improvements for laparoscopic ventral hernia repair (LVHR) have focused on reducing operative time while maintaining overall repair efficacy. Our objective was to evaluate procedure time and positioning accuracy of an inflatable mesh positioning device (Echo PS Positioning System), as compared to a standard transfascial suture technique, using a porcine model of simulated LVHR. Methods. The study population consisted of seventeen general surgeons (n = 17) that performed simulated LVHR on seventeen (n = 17) female Yorkshire pigs using two implantation techniques: (1) Ventralight ST Mesh + Echo PS Positioning System (Echo PS) and (2) Ventralight ST Mesh + transfascial sutures (TSs). Procedure time and mesh centering accuracy overtop of a simulated surgical defect were evaluated. Results. Echo PS demonstrated a 38.9% reduction in the overall procedure time, as compared to TS. During mesh preparation and positioning, Echo PS demonstrated a 60.5% reduction in procedure time (P < 0.0001). Although a trend toward improved centering accuracy was observed for Echo PS (16.2%), this was not significantly different than TS. Conclusions. Echo PS demonstrated a significant reduction in overall simulated LVHR procedure time, particularly during mesh preparation/positioning. These operative time savings may translate into reduced operating room costs and improved surgeon/operating room efficiency
IL-1 receptor antagonist ameliorates inflammasome-dependent inflammation in murine and human cystic fibrosis
Dysregulated inflammasome activation contributes to respiratory infections and pathologic airway inflammation. Through basic and translational approaches involving murine models and human genetic epidemiology, we show here the importance of the different inflammasomes in regulating inflammatory responses in mice and humans with cystic fibrosis (CF), a life-threatening disorder of the lungs and digestive system. While both contributing to pathogen clearance, NLRP3 more than NLRC4 contributes to deleterious inflammatory responses in CF and correlates with defective NLRC4-dependent IL-1Ra production. Disease susceptibility in mice and microbial colonization in humans occurrs in conditions of genetic deficiency of NLRC4 or IL-1Ra and can be rescued by administration of the recombinant IL-1Ra, anakinra. These results indicate that pathogenic NLRP3 activity in CF could be negatively regulated by IL-1Ra and provide a proof-of-concept evidence that inflammasomes are potential targets to limit the pathological consequences of microbial colonization in CF
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