Caratterizzazione dimensionale e morfologica di nanoparticelle lipidiche contenenti molecole farmacologicamente attive

With the advent of nanotechnology, great interest is being dedicated to the interactions of nanomaterials/nanoparticles with human beings. All the interactions occurring due to an intentional exposure are investigated by a new research field named Nanomedicine. As this name may suggest, the use of drug delivery systems, sized in the nanometric scale, may favor overcoming anatomical barriers to reach, passively or by a targeting design, the body area to be pharmacologically treated. In this thesis, we focused our attention to the morphological and dimensional characterization of pharmaceutical lipidic nanoparticles (NP). These carriers were selected because we hypothesized that they could be good candidates for potent but lipophilic drugs that cannot be systemically administered with conventional formulations (e.g., solutions, dispersions). In addition, we focused on their preparation and characterization to evaluate potential therapeutic applications based on shape and size. Specifically, we prepared two types of NP named nanocapsules (NC) and nanoemulsions (NE); the former differs from the latter for a polysaccharidic capsule. Several drugs (ibuprofen and its sodium salt, transretinoic acid, paclitaxel, AZL 6 and 38) and two fluorescently-labeled lipids (i.e.,FITC-PE, NBD) have been entrapped within both NP. We found that lipophilic molecules were completely encapsulated in both NP. In contrast, in the case of the hydrophilic drug, the polysaccharidic capsule causes ibuprofen sodium salt to be entrapped with a greater efficiency in NC than NE (i.e. 92.6 % IE in NC vs. 20.4 % IE in NE). Morphological analysis has been carried out on NP, that were not subjected to a purification treatment, by TEM, and in a few cases also by Cryo-TEM. Although the sample drying step showed to be very critical in producing artifacts, we arrived to the conclusion that particles were spherical. Dimensional analysis has been carried out with TEM and DLS on NP subjected or not-subjected to two different purification methods (i.e., centrifugal filtration, dialysis). The rational of purifica- tion is to remove molecules that, potentially, were not assembled in the NP. The DLS analyses allowed to measure dimensions (Z-Ave) at both 25° and 37°C, and to obtain the polydispersity index(PDI) and superficial charge (ZP). Results showed that NC are positively charged (ca. 45.7 mV) and sized averagely 185-230 nm at 25°C. Their PDI range is 0.145-0.198. In contrast, NE are negatively charged (ca. -58.5 mV) and sized averagely 142-153 nm at 25°C. Their PDI range is 0.111-0.135. By increasing temperature to 37°C, NC and NE dimensions are affected up to a - 10% and + 3 %, respectively. Ranges of PDI change a little, and become 0.131-0.178 and 0.120-0.133 respectively for NC and NE. It seems that temperature might give energy for a better ar- rangement of molecules and drugs. Hence, also ZP changes: in NC it was possible to observe, in almost all cases, a decrease up to 23%. In NE, we observed a correlation between PDI and ZP: e.g.,if PDI increases ZP decreases; in any case, values are not larger than +-17%. Purification by centrifugation differently affects NP. In the case of NC dimensions increase (22-53%) as well as PDI (15-108% = 0.210-0.342), whereas ZP might increase or decrease depend- ing on the entrapped drug (+- 12%). In the case of NE, dimensions stay stable (≤ 1%) but their PDI might change significantly (-2 - +64% = 0.110-0.221), and ZP decreases (0.4-20%). Dialysis is not indifferent either, and results also vary with dialysis time. After 48 h we observed the followings. In the case of NC, dimensions increase (17-52%), PDI decreases (5-46%) and ZP may increase or decrease (-8 - +17%). In the case of NE, dimensions slightly decrease (3-5%), PDI decreases (3-27%), and ZP increases (19-32%). In conclusion, these NP are suitable candidates for further developments on pharmaceutical ap- plications, however their characterization should be accurately set-up to mimic body fluids and conditions at the area to be pharmacologically treated

Photophysics of pentacene-doped picene thin films

Here were report a study of picene nano-cristalline thin films doped with pentacene molecules. The thin films were grown by supersonic molecular beam deposition with a doping concentration that ranges between less than one molecules of pentacene every 104 picene molecules up to about one molecule of pentacene every 102 of picene. Morphology and opto-electronic properties of the films were studied as a function of the concentration of dopants. The optical response of the picene films, characterized by absorption, steady-state and time-resolved photoluminescence measurements, changes dramatically after the doping with pentacene. An efficient energy transfer from the picene host matrix to the pentacene guest molecules was observed giving rise to an intense photoluminescence coming out from pentacene. This efficient mechanism opens the possibility to exploit applications where the excitonic states of the guest component, pentacene, are of major interest such as MASER. The observed mechanism could also serve as prototypical system for the study of the photophysics of host guest systems based on different phenacenes and acenes.Comment: 15 pages, 6 figure

Evolutionary conservation of a regulative pathway of erythropoiesis in Poikilothermic vertebrates

Apoptosis, programmed cell death, plays a central role in haematopoiesis. Mature erythrocytes of non-mammalian vertebrates maintain a permanent nucleus; these cells can undergo apoptosis (eryptosis), as do other somatic cells of a given non-mammalian vertebrate. In this study, we have investigated the expression and subcellular distribution of Bcl-2, Bcl-XL and Bax proteins in the maturation phases and after X-ray irradiation of nucleated erythrocytes of Torpedo marmorata and Caretta caretta and the effect of X-ray irradiation on nucleated circulating erythrocytes of Torpedo marmorata. The cellular distribution of proteins was detected in erythrocytes by using immunocytochemistry at light microscopy and immunoelectron microscopy. The electrophoretic separation and immunoblotting of pro- and anti-apoptotic proteins of immature and mature erythroid cells was performed too, after X-ray irradiation of torpedoes. The results of the immunocytochemical analyses show an increase, in the expression level of Bax in mature as compared to young erythrocytes and a corresponding decrease of Bcl-2 and Bcl-XL. This maturation pattern of Bax, Bcl-2 and Bcl-XL was abrogated in X-ray irradiated torpedo erythrocytes. On the basis of these observations, Bax, Bcl-2 and Bcl-XL seems to play a role in the erythropoiesis of Torpedo marmorata Risso and in Caretta caretta. In conclusion, the same apoptotic proteins of somatic cells appear to be conserved in circulating nucleated erythrocytes thus suggesting to play a role in the maturation of these cells

Tissue resonance interaction accurately detects colon lesions: a double-blind pilot study

AIM: To investigated the performance of the tissue resonance interaction method (TRIM) for the non-invasive detection of colon lesions. METHODS: We performed a prospective single-center blinded pilot study of consecutive adults undergoing colonoscopy at the University Hospital in Sassari, Italy. Before patients underwent colonoscopy, they were examined by the TRIMprobe which detects differences in electromagnetic properties between pathological and normal tissues. All patients had completed the polyethylene glycol-containing bowel prep for the colonoscopy procedure before being screened. During the procedure the subjects remained fully dressed. A hand-held probe was moved over the abdomen and variations in electromagnetic signals were recorded for 3 spectral lines (462-465 MHz, 930 MHz, and 1395 MHz). A single investigator, blind to any clinical information, performed the test using the TRIMprob system. Abnormal signals were identified and recorded as malignant or benign (adenoma or hyperplastic polyps). Findings were compared with those from colonoscopy with histologic confirmation. Statistical analysis was performed by χ2 test. RESULTS: A total of 305 consecutive patients fulfilling the inclusion criteria were enrolled over a period of 12 months. The most frequent indication for colonoscopy was abdominal pain (33%). The TRIMprob was well accepted by all patients; none spontaneously complained about the procedure, and no adverse effects were observed. TRIM proved inaccurate for polyp detection in patients with inflammatory bowel disease (IBD) and they were excluded leaving 281 subjects (mean age 59 ± 13 years; 107 males). The TRIM detected and accurately characterized all 12 adenocarcinomas and 135/137 polyps (98.5%) including 64 adenomatous (100%) found. The method identified cancers and polyps with 98.7% sensitivity, 96.2% specificity, and 97.5% diagnostic accuracy, compared to colonoscopy and histology analyses. The positive predictive value was 96.7% and the negative predictive value 98.4%. Among the 281 non-IBD subjects, there were 7 cases with discordant results (2.5%) between TRIMprob and the reference standard including 5 false positive results (1.8%) and 2 false negative (0.7%) results. The main limitation of the TRIMprob system is the need for trained operators. CONCLUSION: The study confirmed that TRIM provides rapid, accurate, convenient and noninvasive means to identify individuals most likely to benefit from colonoscopy

intravenous versus oral vinorelbine plus capecitabine as second line treatment in advanced breast cancer patients a retrospective comparison of two consecutive phase ii studies

Abstract Vinorelbine (i.v.) plus capecitabine (oral) combination therapy is active in anthracycline/taxane pretreated patients with metastatic breast cancer. Availability of oral vinorelbine provides this combination in an all-oral formulation. Two consecutive phase II trials differing only in vinorelbine administration routes evaluated their respective activities and tolerabilities in this population. In the i.v. group ( n = 38) disease control was 61% (37% PR, 24% SD), median TTP 6.8 months and median survival 11.3 months. In the oral group ( n = 38) disease control was 77% (5.4% CR, 34% PR, 38% SD), median TTP 7 months and median survival 10 months. G3–G4 neutropenia was more common in the oral group (