Search results for "FARMACEUTICO"

Synthesis of Novel Folic Acid-Functionalized Biocompatible Block Copolymers by Atom Transfer Radical Polymerization for Gene Delivery and Encapsulati…

2005

Two synthetic routes to folic acid (FA)-functionalized diblock copolymers based on 2-(methacryloyloxy)- ethyl phosphorylcholine [MPC] and either 2-(dimethylamino)ethyl methacrylate [DMA] or 2-(diisopropylamino) ethyl methacrylate [DPA] were explored. The most successful route involved atom transfer radical polymerization (ATRP) of MPC followed by the tertiary amine methacrylate using a 9-fluorenylmethyl chloroformate (Fmoc)-protected ATRP initiator. Deprotection of the Fmoc groups produced terminal primary amine groups, which were conjugated with FA to produce two series of novel FA-functionalized biocompatible block copolymers. Nonfunctionalized MPC-DMA diblock copolymers have been previou…

CONTROLLED RELEASE OF IgG BY NOVEL UV INDUCED POLYSACCHARIDE/POLY(AMINO ACID)HYDROGELS

2009

The development of new protein and peptide drugs needs new delivery systems able to entrap such drugs in safe conditions without affecting their structure and biological activity. In this context, the present work reports a new approach to load IgG, used as a model of therapeutic proteins such as anti-TNF-alpha monoclonal antibodies, into a polymeric system able to release the entrapped IgG in a controlled manner. In particular, new polysaccharide/poly(amino acid) UV induced hydrogels are proposed as colon delivery systems for human IgG. The poly(amino acid), alpha,beta-poly[N-(2-hydroxyethyl)-D,L-aspartamide], has been functionalized with methacrylic anhydride, while the polysaccharide, in…

Correlating Rheological Properties of a Gellan Gum-Based Bioink: A Study of the Impact of Cell Density.

2022

Here, for the production of a bioink-based gellan gum, an amino derivative of this polysaccharide was mixed with a mono-functionalized aldehyde polyethyleneglycol in order to improve viscoelastic macroscopic properties and the potential processability by means of bioprinting techniques as confirmed by the printing tests. The dynamic Schiff base linkage between amino and aldehyde groups temporally modulates the rheological properties and allows a reduction of the applied pressure during extrusion followed by the recovery of gellan gum strength. Rheological properties, often related to printing resolution, were extensively investigated confirming pseudoplastic behavior and thermotropic and io…

Mucoadhesive polymers for oral transmucosal drug delivery: a review.

2012

The oral mucosa offers an interesting site for the application of dosage forms that release drugs within/throughout the oral mucosa, by assuring a high drug bioavailability for topic and systemic effects. However, the relative permeability of the oral mucosa and the washing effect related to the oral fluids and mechanical stresses must be considered in the formulation of oral dosage forms. Since a sustained drug release can be guaranteed only if dosage forms remain in contact with the oral site of absorption/application for a prolonged time, the development of mucoadhesive dosage forms is mandatory. The mucoadhesion is a complex phenomenon and the mucoadhesive bond consists of two different…

Interaction Between drug loaded Polyaspartamide-polylactide-polisorbate based micelles and cell membrane models: a calorimetric study

2011

Amphiphilic biodegradable copolymers, for their ability to self-assemble into micelle-like aggregates, with a suitable loading capacity, are of emerging interest for the delivery of water-insoluble drugs. α,β-Poly[(N-hydroxyethyl)-dl-aspartamide] (PHEA) is suitable to obtain amphiphilic graft copolymers. These copolymers can be obtained starting from PHEA-ethylenediamine (PHEA-EDA) which is functionalized with polysorbate 80 (PS₈₀, like targeting residues to the brain) and polylactide (PLA, like hydrophobic chains) in order to obtain polymeric micelles of PHEA-EDA-PS₈₀-PLA potentially useful to release drugs to the central nervous system. In this paper, the interaction and absorption of PHE…

The New Life Of Exhausted Bentonite From The Grape Processing Industry: From Waste To Precious Resource To Produce Novel Raw Materials Enriched In Po…

Introduction: In an ever-growing perspective of circular economy, the development of conscious, sustainable and environmental-friendly strategies to recycle the waste products is the key point1. The exhausted bentonite, from the grape processing industries, could become a precious matrix to produce new pharmaceutical/cosmetic excipients enriched in functional polyphenols2. Materials & Methods: The exhausted bentonite recovered after the fining process (supplied by Bono&Ditta s.p.a., Campobello di Mazara TP, Italy) was stored at -20°C. Solid-liquid extractions on both freeze-dried and as-collected (wet) bentonite were carried out by using PEG200 or propylene glycol as solvents. The l…

Synthesis and characterization of redox-sensitive polyurethanes based on L-glutathione oxidized and poly(ether ester) triblock copolymers

2021

Abstract Segmented polyurethanes, based on PCL-PEG-PCL copolymers, 1,4-diisocyanatobutane and l -glutathione oxidized, used as chain extender, were synthetized. Three different reactions conditions were investigated using three different copolymers having ɛ-CL/polyethylene glycol molar ratios equal to 12, 24 and 36 and three different reaction conditions. As investigated by size exclusion chromatography analyses and quantification of l -glutathione, the polymerization and the extension phase's efficiency depended on the ɛ-CL/PEG ratio and the extension phase's operating temperature. Three selected polyurethanes were characterized by spectroscopic, differential scanning calorimetry (DSC) and…

Inhalable polymeric microparticles as pharmaceutical porous powder for drug administration

2022

In this work, the production of inhalable polymeric microparticles with modulable porosity is described. The starting polymeric material was the PHEA-g-RhB-g-PLA graft copolymer, which was suitably processed by spray drying (SD). Thanks to the addition of AB (weight percentage equal to 10 and 20 % with respect to the polymer) in the liquid feed, three biocompatible matrices were obtained with an increasing porosity in terms of pore volume (from 0.015 to 0.024 cc/g) and pore average diameter (from 1.942 to 3.060 nm), a decreasing tapped density values (from 0.75 to 0.50), and favorable aerosolization characteristics. These differences were high-lighted also by a significant increase in the r…

Polyanion–tobramycin nanocomplexes into functional microparticles for the treatment of Pseudomonas aeruginosa infections in cystic fibrosis

2016

Aim: Efficacy of antibiotics in cystic fibrosis (CF) is compromised by the poor penetration through mucus barrier. This work proposes a new ‘nano-into-micro’ approach, used to obtain a combinatorial effect: achieve a sustained delivery of tobramycin and overcome mucus barrier. Methods: Mannitol microparticles (MPs) were loaded with a tobramycin polymeric nanocomplex and characterized in presence of CF artificial mucus. Results & discussion: MPs are able to alter the rheological properties of CF artificial mucus, enhancing drug penetration into it and allowing a prolonged drug release. MPs resulted to be effective in Pseudomonas aeruginosa infections if compared with free tobramycin. Co…

Nanocomplexes for gene therapy of respiratory diseases: Targeting and overcoming the mucus barrier

2015

Gene therapy, i.e. the delivery and expression of therapeutic genes, holds great promise for congenital and acquired respiratory diseases. Non-viral vectors are less toxic and immunogenic than viral vectors, although they are characterized by lower efficiency. However, they have to overcome many barriers, including inflammatory and immune mediators and cells. The respiratory and airway epithelial cells, the main target of these vectors, are coated with a layer of mucus, which hampers the effective reaching of gene therapy vectors carrying either plasmid DNA or small interfering RNA. This barrier is thicker in many lung diseases, such as cystic fibrosis. This review summarizes the most impor…