Contribution of Intrinsic Fluorescence to the Design of a New 3D-Printed Implant for Releasing SDABS.

Single-domain antibodies (sdAbs) offer great features such as increased stability but are hampered by a limited serum half-life. Many strategies have been developed to improve the sdAb half-life, such as protein engineering and controlled release systems (CRS). In our study, we designed a new product that combined a hydrogel with a 3D-printed implant.

Optimization of magnetic retention in the gastrointestinal tract: Enhanced bioavailability of poorly permeable drug.

Oral administration of low permeable drugs remains a challenge as they do not cross biological membrane efficiently and therefore exhibit a poor bioavailability. Herein, the effect of magnetic retention on the circulation and bioavailability of magnetic beads in the gastrointestinal tract in the presence of an external magnetic field is evaluated. Retention efficiency is imaged using magnetic resonance and near infrared techniques.

Performance of magnetic chitosan-alginate core-shell beads for increasing the bioavailability of a low permeable drug.

This work reports the synthesis and performance of magnetic chitosan-alginate core-shell beads for oral administration of small molecules in order to increase their bioavailability. For this purpose, we designed magnetic core-shell beads suitable for oral delivery that are resistant in acidic media (stomach pH), mucoadhesive, exhibit a superparamagnetic behavior and a very high entrapment efficiency. Ex vivo experiments were performed in Ussing chambers, to emphasize the effect of magnetic accumulation.

Novel surfactants with diglutamic acid polar head group: drug solubilization and toxicity studies.

Purpose: Novel surfactants made of diglutamic acid (DG) polar head linked to lithocholic, arachidonic, linoleic or stearic acids were designed for drug solubilization.

Methods: Surfactants 3-D conformer and packing parameter were determined by molecular modelling and self-assembling properties by pyrene fluorescence measurements. Cytotoxicity was assessed on Human Umbilical Vein Endothelial Cells (HUVEC) and haemolyitic activity on rat red blood cells.

Drug solubilization and in vitro toxicity evaluation of lipoamino acid surfactants.

To improve solubilization of a water insoluble anticancer drug, novel surfactants were synthesized. All surfactants derived from lysine, with a so-called nitrilo triacetic acid (NTA) polar head, and differed from the length and saturation degree of their hydrophobic moieties: C19:0-NTA, C20:4-NTA, C25:0-NTA and C25:4-NTA. Self-assembling properties and critical micellar concentration (CMC) values were determined using pyrene fluorescence and cytotoxicity using MTT and LDH assays on endothelial cells.

Physicochemical characterization and toxicity evaluation of steroid-based surfactants designed for solubilization of poorly soluble drugs.

To overcome poor water-solubility of new drug candidates, four innovative surfactants based on naturally-occuring hydrophilic and hydrophobic moities were designed and synthesized: cholesteryl-glutamic acid, cholesteryl-poly[N-2-hydroxyethyl-l-glutamine] (PHEG), ursodeoxycholanyl-PHEG (UDCA-PHEG) and ursodeoxycholanyl-poly-l-glutamic acid (UDCA-PGA). Their self-assembling capacity was evaluated using pyrene fluorescence measurements which allow to determine their critical aggregation concentration (CAC). Size measurements were carried out using dynamic light scattering (DLS).

Intracellular trafficking of Shiga-toxin-B-subunit-functionalized spherulites.

Background Information: Spherulites are multi-lamellar lipidic vesicles that can encapsulate biomolecules and may be used as carriers for drug delivery. STxB (Shiga toxin B-subunit) is known to bind the glycosphingolipid Gb3 (globotriaosyl ceramide), which is overexpressed by various human tumours. After Gb3 binding, the toxin enters the cytoplasm via the retrograde route, bypassing the degrading environment of the late endosomes/lysosomes.

Synthesis of versatile chemical tools toward a structure/properties relationships study onto targeting colloids.

As part of a drug delivery project, four aldehydes of the type Pam-Lys(Pam)-spacer-CO-CHO were synthesized to be included in targeting colloids. Though amphiphilic, they were obtained within reasonable yields (18-55%) and with high RP-HPLC purity ( approximately 90%). Parallely, six complementary targeting peptides of the type H(2)N-NH-CH(2)-CO-spacer-YGRGDSP-NH(2) were prepared to be anchored onto colloids.