Search results for "TECNOLOGICO"
showing 10 items of 440 documents
Phospholipid-polyaspartamide micelles for pulmonary delivery of corticosteroids
2011
A novel drug delivery system for beclomethasone dipropionate (BDP) has been constructed through self-assembly of a pegylated phospholipid-polyaminoacid conjugate. This copolymer was obtained by chemical reaction of α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHEA) with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethyleneglycol)2000] (DSPE-PEG(2000)-NH(2)). Benefiting from the amphiphilic structure with the hydrophilic shell based on both PHEA and PEG and many hydrophobic stearoyl tails, PHEA-PEG(2000)-DSPE copolymer was able to self assemble into micelles in aqueous media above a concentration of 1.23 × 10(-7)M, determined by fluorescence studies. During the self-assembling …
New pegylated polyaspartamide-based polyplexes as gene delivery vectors
2010
Aims: To synthesize novel polyhydroxyethylaspartamide (PHEA) copolymers containing spermine (Spm) and polyethylene glycol (PEG) moieties in high yields, with the expectation that this material would show stealth properties and the ability to complex DNA by electrostatic interactions. Materials & methods: PHEA–PEG–Spm copolymer was prepared with a two-step reaction. Chemical, physicochemical and biological characterizations of PHEA–PEG–Spm copolymers and their obtained polyplexes with pDNA were performed. Results: The introduction of spermine in PHEA structure allows to obtain a copolymer bearing in the side chains polyamine moieties capable to interact with DNA. On the other hand, the …
Gold nanoparticles/electrochemically expanded graphite composite: A bifunctional platform toward glucose sensing and SERS applications
2019
Abstract An integrated nanogold/expanded graphite based sensor was fabricated by a former electrochemical etching of the pencil lead electrode (PLE) and a later in-situ deposition of gold nanoparticles (AuNPs). The electrochemical pretreatment of PLE (EPLE) created a 3D graphene-like surface, enhanced the electrode surface area and facilitated the electron transfer ability within 5 min without any hazardous chemicals added. The obtained AuNPs/EPLE sensor had an excellent electrochemical response to glucose with a wide linear concentration range, from 0.05 to 38 mM and 38 to 60 mM, and a low detection limit of 5 μM (S/N = 3). Furthermore, the AuNPs/EPLE sensor was successfully employed to de…
SISTEMI NANOSTRUTTURATI POLIMERICI PER LA VEICOLAZIONE ED IL RILASCIO DI FARMACI
2011
Carbon Nanodots as Functional Excipient to Develop Highly Stable and Smart PLGA Nanoparticles Useful in Cancer Theranostics
2020
Theranostic systems have attracted considerable attention for their multifunctional approach to cancer. Among these, carbon nanodots (CDs) emerged as luminescent nanomaterials due to their exceptional chemical properties, synthetic ease, biocompatibility, and for their photothermal and fluorescent properties useful in cancer photothermal therapy. However, premature renal excretion due to the small size of these particles limits their biomedical application. To overcome these limitations, here, hybrid poly(lactic-co-glycolic acid) (PLGA-CDs) nanoparticles with suitable size distribution and stability have been developed. CDs were decisive in the preparation of polymeric nanoparticles, not on…
Highly Homogeneous Biotinylated Carbon Nanodots: Red-Emitting Nanoheaters as Theranostic Agents toward Precision Cancer Medicine
2019
Very recent red-emissive carbon nanodots (CDs) have shown potential as near-infrared converting tools to produce local heat useful in cancer theranostics. Besides, CDs seem very appealing for clinical applications combining hyperthermia, imaging, and drug delivery in a single platform capable of selectively targeting cancer cells. However, CDs still suffer from dramatic dot-to-dot variability issues such that a rational design of their structural, optical, and chemical characteristics for medical applications has been impossible so far. Herein, we report for the first time a simple and highly controllable layer-by-layer synthesis of biotin-decorated CDs with monodisperse size distribution, …
Hyaluronan-Based Graft Copolymers Bearing Aggregation-Induced Emission Flurogens
2017
In order to develop a technology platform based on two natural compounds from biorenewable resources, a short series of hyaluronan (HA) copolymers grafted with propargylated ferulic acid (HA-FA-Pg) were designed and synthesized to show different grafting degree values and their optical properties were characterized in comparison with reference compounds containing the same ferulate fluorophore. Interestingly, these studies revealed that the ferulate fluorophore was quite sensitive to the restriction of intramolecular motion and its introduction into the rigid HA backbone, as in HA-FA-Pg graft copolymers, led to higher photoluminescence quantum yield values than those obtained with the isola…
Multicomponent polymeric micelles based on polyaspartamide as tunable fluorescent pH-window biosensors
2010
Abstract PHEA-PEG 5000 -C 16 is a polyaspartamide polymer with appended hydrophilic PEG 5000 functions and hydrophobic n-C 16 units forming biocompatible micelles with a CAC as low as 1.8 × 10 −7 M. The protonation and acidity constants of the polymer's amino and carboxylic groups have been determined by potentiometric titrations at five different concentrations higher than CAC, finding concentration-independent values. Viscosity and polarity of the micellar core have been investigated by means of fluorescent probes, finding local values comparable to those of pure toluene and to the core of sodium dodecyl sulphate micelles, independently on the protonation degree of the polymer. The fluor…
A fluorescent molecular sensor for pH windows in traditional and polymeric biocompatible micelles: comicellization of anionic species to shift and re…
2011
A new approach is presented to obtain fluorescent sensors for pH windows that work in water and under biomimetic conditions. A single molecule that features all-covalently linked components is used, thus making it capable of working as a fluorescent sensor with an OFF/ON/OFF response to pH value. The components are a tertiary amine, a pyridine, and a fluorophore (pyrene). The forms with both protonated bases or both neutral bases quench the pyrene fluorescence, whereas the form with the neutral pyridine and protonated amine groups is fluorescent. The molecular sensor is also equipped with a long alkyl chain to make it highly hydrophobic in all its protonated and unprotonated forms, that is,…