Development of a cationic bacterial cellulose film loaded with anionic liposomes for prolonged release of oxacillin in wound dressing applications.

Dressings should protect wounds, promote healing, absorb fluids, and maintain moisture. Bacterial cellulose is a biopolymer that stands out in biomaterials due to its high biocompatibility in several applications. In the area of dressings, it is already marketed as an alternative to traditional dressings.

DoE development of ionic gradient liposomes: A successful approach to improve encapsulation, prolong anesthesia and decrease the toxicity of etidocaine.

Etidocaine (EDC) is a long-acting local anesthetic of the aminoamide family whose use was discontinued in 2008 for alleged toxicity issues. Ionic gradient liposomes (IGL) are nanostructured carriers for which an inner/outer gradient of ions increases drug upload. This work describes IGL, a formulation optimized by Design of Experiments, composed of hydrogenated soy phosphatidylcholine:cholesterol:EDC, and characterized by DLS, NTA, TEM/Cryo-TEM, DSC and H NMR.

Inclusion Complex between Local Anesthetic/2-hydroxypropyl-β-cyclodextrin in Stealth Liposome.

The drugs delivery system in the treatment of diseases has advantages such as reduced toxicity, increased availability of the drug, etc. Therefore, studies of the supramolecular interactions between local anesthetics (LAs) butamben (BTB) or ropivacaine (RVC) complexed with 2-hydroxypropyl-β-cyclodextrin (HP-βCD) and carried in Stealth liposomal (SL) are performed. H-NMR nuclear magnetic resonance (DOSY and STD) were used as the main tools.

Liposome surface modification by phospholipid chemical reactions.

Liposomal systems are well known for playing an important role as drug carriers, presenting several therapeutic applications in different sectors, such as in drug delivery, diagnosis, and in many other academic areas. A novel class of this nanoparticle is the actively target liposome, which is constructed with the surface modified with appropriated molecules (or ligands) to actively bind a target molecule of certain cells, system, or tissue. There are many ways to functionalize these nanostructures, from non-covalent adsorption to covalent bond formation.

Physicochemical characterization and cytotoxicity of articaine-2-hydroxypropyl-β-cyclodextrin inclusion complex.

Articaine (ATC) is one of the most widely used local anesthetics in dentistry. Despite its safety, local toxicity has been reported. This study aimed to develop an ATC-2- hydroxypropyl-β-cyclodextrin inclusion complex (ATC HPβCD) and to assess its toxicity in vitro.

Anaesthetic benefits of a ternary drug delivery system (Ropivacaine-in-Cyclodextrin-in-Liposomes): in-vitro and in-vivo evaluation.

Objectives: To evaluate whether a ternary system composed of hydroxypropyl-β-cyclodextrin (HP-βCD) further encapsulated into egg phosphatidylcholine liposomes (LUV) could prolong the action and reduce the toxicity of ropivacaine (RVC).

Methods: Dynamic light scattering and NMR were used to characterize the inclusion complex (RVC : HP-βCD), liposomal (RVC : LUV) and ternary (LUV : RVC : HP-βCD) systems containing 0.25% RVC.

Combining nuclear magnetic resonance with molecular dynamics simulations to address sumatriptan interaction with model membranes.

The goal of this work is to obtain a complete map on the interactions between sumatriptan, an amphiphilic ionizable anti-migraine drug, with lipid bilayers. To this end, we combined two physico-chemical techniques - nuclear magnetic resonance and molecular dynamics simulations - to obtain a detailed picture at different pH values. Both approaches were used considering the strength and constraints of each one.

In situ study of the magnetoelectrolysis phenomenon during copper electrodeposition using time domain NMR relaxometry.

Although the effect of magnetic field (B) on electrochemical reactions (magnetoelectrolysis phenomenon) has been long known, it has not been considered in electrochemical reactions analyzed in situ by magnetic resonance methods, such as nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR), and magnetic resonance imaging (MRI), which are intrinsically performed in the presence of B. In this report, the effect of B on the copper electrodeposition reaction, measured by a low-field (0.23 T) NMR spectrometer, was demonstrated.

Improvement of tetracaine antinociceptive effect by inclusion in cyclodextrins.

Local anesthetics (LA) are among the most important pharmacological compounds used to attenuate or eliminate pain. However, systemic toxicity is still a limitation for LA application, especially for ester-type drugs, such as tetracaine (TTC) that presents poor chemical stability (due to hydrolysis by plasma esterases). Several approaches have been used to improve LA pharmaceutical properties, including the employment of drug-delivery systems.

Prilocaine-cyclodextrin-liposome: effect of pH variations on the encapsulation and topology of a ternary complex using 1H NMR.

A better comprehension of the prilocaine (PLC)-β-cyclodextrin (β-CD) complex liberation to membranes was provided by studying the architectural supramolecular arrangements of PLC, β-CD and egg phosphatidylcholine (EPC) liposomes, a membrane model. The topologies and possible interactions of mixtures of PLC, β-CD and EPC liposomes were investigated by nuclear magnetic resonances combining experimental (1)H-NMR (1D ROESY, STD and DOSY) at different pHs. The results indicate that in the mixture PLC/β-CD/EPC at pH 10 the PLC molecules are almost totally embedded into the liposomes and little interaction was observed between PLC and β-CD.

Topology of a ternary complex (proparacaine-beta-cyclodextrin-liposome) by STD NMR.

The topologies of proparacaine (PPC) in beta-cyclodextrin (beta-CD), PPC in egg phosphatidylcholine (EPC) liposomes and PPC in beta-CD in EPC were investigated using NMR experiments (1D ROESY and saturation transfer difference (STD)). This is the first description of the STD technique applied to PPC-EPC-beta-CD system, revealing that not only PPC was imbedded in EPC bilayer, but beta-CD was also interacting with liposome vesicles. These results are novel and were rationalized as the spontaneous formation of a ternary complex with some beta-CD molecules bound to external liposome vesicles surfaces.