MORFEO enters final design phase

MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations, formerly MAORY), the MCAO system for the ELT, will provide diffraction-limited optical quality to the large field camera MICADO. MORFEO has officially passed the Preliminary Design Review and it is entering the final design phase. We present the current status of the project, with a focus on the adaptive optics system aspects and expected milestones during the next project phase

Nuovi agenti per la terapia fotodinamica basati su nanosistemi

This PhD thesis describes the development of silica nanocarriers that will be potentially useful in photodynamic therapy. The research described in this thesis was conducted within the Nanophoto project, a EU-funded collaborative effort to address the current limitations of photodynamic therapy through nanotechnology. A new strategy for the one-step synthesis of highly PEGylated ORMOSIL silica nanoparticles doped with hydrophobic molecules for use as drug carriers is presented, in particular for PDT. Thanks to this procedure, size of prepared nanoparticles can be controlled in the range between 10 and 200 nm, and purification procedures are much simpler than those involved in current literature methods. The dense PEG layer makes the nanoparticles stable by aggregation in saline medium and in a biological environment and endows them at the same time with stealth properties (capture resistence from immunitary system cells) both in vitro and in vivo. As a consequence, the drug concentration in tumoral tissues is increased significantly by the EPR effect (Enhanced Permeability and Retention). The photosintetizer used in my thesis is meta-tetra(hydroxyphenyl)chlorin (mTHPC), anticancer and dermatological drug: its forniture was provided by Biolitec, one of the partner of the Nanophoto project. However, the PEG coating is not completely effective in preventing the release of the photosensitizer mTHPC in the presence of serum, a problem that hampered our previous attempts. The drug was then modified so that it could be covalently anchored to the nanoparticles, and the effects on its physical and chemical properties after derivatization and grafting to the silica matrix were investigated. The new procedure also enables the introduction of functional groups on the PEG layer at the same time of nanoparticle’s formation. These reactive moieties can be used for the subsequent conjugation of small organic molecules, such as folic acid or biotin, or the bioconjugation of antibodies and other biomolecules so as to obtain targeted nanoparticles. Encouraging resultswere demonstrated in active targeting experiments with monoclonal antibodies, such as those for D2B, specific for prostatic tumoral antigen, and EGF (Epidermial Growth Factor).Questa tesi di dottorato si inserisce nel campo della nanomedicina e si occupa della realizzazione di nanovettori di silice per potenziali applicazioni nella terapia fotodinamica (PDT). Questo lavoro di tesi era inserito nel progetto Nanophoto, finanziato dalla comunità europea e a cui partecipano diversi gruppi di ricerca e imprese italiani ed europei. Più in particolare, la tesi discute di una nuova procedura sintetica che consente di realizzare in un unico step nanoparticelle di silice organicamente modificata (ORMOSIL) ricoperte con un denso strato di PEG e caricate con molecole idrofobiche, tra cui fluorescenti e foto sensibilizzatori per la PDT. Grazie a questa procedura è possibile controllare il diametro delle nanoparticelle preparate in un intervallo tra 10 e 200 nm e la purificazione delle preparazioni è stata molto semplificata. Lo strato di PEG dei carrier è estremamente denso, tanto da rendere le nanoparticelle stabili contro l’aggregazione anche in mezzi salini ed in ambiente biologico, e da conferire loro notevoli abilità stealth (resistenza alla cattura da parte di cellule del sistema immunitario) sia in vitro che in vivo e da incrementare notevolmente l’accumulo nei tessuti tumorali in virtù dell’effetto EPR (Enhanced Permeability and Retention). Il fotosensibilizzatore utilizzato in questo lavoro di tesi è la tetra(metaidrossifenil)clorina (mTHPC), già commercializzata come farmaco antitumorale e dermatologico e fornita dalla ditta Biolitec, che è coinvolta nel progetto Nanophoto. La speranza iniziale era quella di poter intrappolare fisicamente l’THPC nelle nanoparticelle senza necessità di modificarlo. Tuttavia studi effettuati nell’ambito del progetto e del mio lavoro di tesi hanno dimostrato che il fotosensibilizzatore viene rapidamente rimosso dalle nanoparticelle in presenza di proteine del siero. Neppure il coating di PEG, che sfavorisce l’interazione delle particelle con le proteine, è capace di arrestare la fuga dell’mTHPC. Il fotosensibilizzatore è stato quindi modificato chimicamente per consentirgli di ancorarsi covalentemente alla matrice dellananoparticella. L’elaborato discute gli effetti della funzionalizzazione e del legame con la matrice silicea sulle caratteristiche dell’ mTHPC. La nuova procedura di sintesi messa a punto permette inoltre di introdurre dei gruppi funzionali nello strato di PEG contemporaneamente alla formazione delle particelle. Questi gruppi funzionali possono essere utilizzati per una successiva coniugazione con piccole molecole organiche, come acido folico e biotina, oppure per la bioconiugazione di anticorpi e altre biomolecole e ottenere così nanoparticelle direzionanti. Risultati particolarmente incoraggianti sono stati ottenuti in queste strategie di targeting attivo con anticorpi monoclonali come il D2B, specifico per l’antigene deltumore prostatico, e con ligandi di recettori sovraespressi dai tumori come l’EGF (Epidermial Growth Factor)

Targeted Silica Nanoparticles for PhotoDynamic Therapy (PDT)

In the last decade, engineered nanoparticles have become an important class of new materials with several properties that make them very attractive in a variety of fields. In particular, nanotechnology has been applied to diverse medical and biological applications ranging from biomarkers and molecular diagnostics to drug discovery and drug delivery. The importance of such applications pushed the National Institute of Health (USA) to introduce the term \u201cnanomedicine\u201d to describe the nanotechnologies applied to human diseases[1]. The peculiar properties of silica nanoparticles make them well suited to the development of smart nanomaterials for medicine and particularly for Photo Dynamic Therapy (PDT) and imaging

Catastrophic inflammatory death of monocytes and macrophages by overtaking of a critical dose of endocytosed synthetic amorphous silica nanoparticles/serum protein complexes

Aims: We tested whether phagocytic monocytes/macrophages are more susceptible than nonphagocytes to nanoparticle (NP) toxicity. Materials & methods: We compared in vitro cell death and proinflammatory cytokine production in human monocytes, macrophages, lymphocytes and HeLa cells due to synthetic amorphous silica (SiO2)-NPs in different serum concentrations and correlated them with cellular uptake and distribution. Results: Phagocytes were approximately ten-times more sensitive than nonphagocytes to SiO2-NPs and more effectively endocytosed SiO2-NP\u2013serum protein nanoagglomerates, so determining their accumulation in acidic endocytic compartments well beyond a critical/cytotoxic threshold. Monocyte/macrophage death was paralleled by cytokine secretion. Conclusion: The physiological specialization of monocytes/macrophages to effectively capture NPs may expose them to the risk of catastrophic inflammatory death upon saturation of their maximal storage capacity

A Cell-Penetrating Ratiometric Nanoprobe for Intracellular Chloride

NanoChlor, a nanoparticle-based fluorescent probe for chloride that is both ratiometric and capable of spontaneously penetrating neuronal cells at submillimolar concentrations, was designed and studied. NanoChlor is built on silica nanoparticles grafted with 6-methoxyquinolinium as the chloride-sensitive component and fluorescein as the reference dye. A Stern\u2013Volmer constant of 50 M\u20131 was measured in Ringer\u2019s buffer at pH 7.2, and the response to chemically induced chloride currents was recorded in real time in hippocampal cells

The toxicity outcome of silica nanoparticles (Ludox\uae) is influenced by testing techniques and treatment modalities

We analyzed the influence of the kind of cytotoxicity test and its application modality in defining the level of hazard of the in vitro exposures to nanostructures. We assessed the cytotoxicity induced by two different Ludox\uae silica nanoparticles (NPs), AS30 and SM30, on three human cell lines, CCD\u201034Lu, A549, and HT\u20101080. Dynamic light scattering measurements showed particle agglomeration when NPs are diluted in culture medium supplemented with fetal calf serum. We examined the impact of such particle aggregation on the cytotoxicity by exposing the cells to NPs under different treatment modalities: short incubation (2 h) in serum\u2010free medium or long incubation (24\u201372 h) in serum\u2010containing medium. Under this last modality, NP suspensions tended to form aggregates and were toxic at concentrations five\u2010 to tenfold higher than in serum\u2010free medium. The results of cell survival varied considerably when the long\u2010term clonogenic assay was performed to validate the data of the short\u2010term MTS assay. Indeed, the half maximum effective concentrations (EC50) in all the three cell lines were four\u2010 to fivefold lower when calculated from the data of clonogenic assay than of MTS. Moreover, the mechanisms of NP toxicity were cell\u2010type\u2010specific,showing that CCD\u201034Lu are prone to the induction of plasma membrane damages and HT\u20101080 are prone to DNA double\u2010strand break and apoptosis induction. Taken together, our results demonstrate that the choice of testing strategy and treatment conditions plays an important role in assessing the in vitro toxicity of NPs

Nanovehicles loaded with meta-tetra(hydroxyphenyl)chlorine for photodynamic treatment of cancer

none86th International Conference Biomedical Applications of Nanotechnology (NanoMed). Charité , BerlinoAbstractnoneMORET F; COMPAGNIN C; RIO I; SELVESTREL F; MOGNATO M; CELOTTI L; MANCIN F; REDDI E.Moret, F; Compagnin, C; Rio, I; Selvestrel, F; Mognato, Maddalena; Celotti, L; Mancin, Fabrizio; Reddi, Elen