Effect of graphene oxide on sodium alginate hydrogel as a carrier triggering release of ibuprofen.

The design and preparation of safe wound dressings with antibacterial and controlled drug release abilities is valuable in medicine. This research focuses on the fabrication of a hydrogel carrier with graphene oxide (GO)-triggered ibuprofen (IBU) release to control inflammation. The hydrogel was prepared by cross-linking the base polymer sodium alginate (SA) and functionalized GO. The morphology of the gel was observed by a scanning electron microscope (SEM), and its structure was analyzed through X-ray diffraction (XRD) and Fourier transform infrared reflection (FTIR) spectroscopy. The effects of GO on swelling capacity, IBU release behavior and antibacterial activity were investigated by using the prepared GO/SA hydrogel as a drug carrier and IBU as a drug model. In vitro studies confirmed that the GO/SA hydrogel had good antimicrobial activity and excellent cytotoxicity. The analysis of cumulative IBU release rates revealed that the addition of GO could promote the release of IBU, and the change in GO content did not have a prominent effect on IBU release. At the same time, the rate of IBU release from the GO/SA hydrogel was affected by near-infrared light. Under a light source, the release rate of IBU increased, and the release amount of IBU showed a clear stepwise increase under light on-off conditions. These results suggest that the GO/SA hydrogel could be a potential antibacterial and anti-inflammatory wound dressing.

Fast and reliable analysis of pH-responsive nanocarriers for drug delivery using microfluidic tools.

During the last decades, there has been growing interest in the application of functionalized mesoporous nanomaterials as stimuli-responsive carriers for drug delivery. However, at present there is not a standardized methodology to evaluate their performance. The limitations of the different techniques reported in literature give rise to the necessity for new, simple, and cost-effective alternatives. This work constitutes a step forward in the development of advanced in vitro procedures for testing the behavior of nanocarriers, proposing a novel microfluidic platform. To test the capacity of the reported tool, the performance of amino-functionalized MCM-41 nanoparticles has been assessed. These materials show a pH-responsive mechanism, which prevents the drug release at acidic conditions, maximizing its distribution at neutral pH, thus, the selected release medium mimicked gastrointestinal conditions. As a first approximation, the delivery of Ru(bipy)32+ was evaluated, proving the advantages of the proposed microfluidic system: i) continuous flow of particles and media, ii) rigorous control of the residence time, temperature and pH, iii) enhanced mixing, iv) possibility to simulate different human body conditions and, v) possible integration with the continuous synthesis of nanocarriers. Finally, the microfluidic tool was used to analyze the delivery of the anti-inflammatory drug ibuprofen.

Controlled ibuprofen release from Pickering emulsions stabilized by pH-responsive cellulose-based nanofibrils.

Pickering emulsions represent a promising avenue in the field of controlled drug delivery systems. Recently, cellulose nanofibers (CNFs) and chitosan nanofibers (ChNFs) have gained interest as eco-friendly stabilizers for Pickering emulsions, yet their application in pH-responsive drug delivery systems remains unexplored. However, the potential of these biopolymer complexes in formulating stable, pH-responsive emulsions for controlled drug release is of significant interest. Here, we show the development of a highly stable, pH-responsive fish oil-in-water Pickering emulsion stabilized by ChNF/CNF complexes, with optimal stability achieved at a 0.2 wt% ChNF concentration and an average emulsion particle size of approximately 4 µm. Our results demonstrate long-term stability (16 days of storage) for ChNF/CNF-stabilized emulsions, with the interfacial membrane's pH modulation facilitating controlled, sustained ibuprofen (IBU) release. Furthermore, we observed a remarkable release of approximately 95 % of the embedded IBU within the pH range of 5-9, while the drug loading and encapsulation efficiency of the drug-loaded microspheres reached their peak at a 1 % IBU dosage, with values of 1 % and 87 %, respectively. This study highlights the potential of using ChNF/CNF complexes in designing versatile, stable, and entirely renewable Pickering systems for controlled drug delivery, with potential applications in food and eco-friendly products.

Bovine serum albumin-sodium alkyl sulfates bioconjugates as drug delivery systems.

Precipitation of bovine serum albumin (BSA) by anionic surfactants with alkyl chains of increasing lengths (octyl, decyl, dodecyl sulfates) was studied at room temperature, at pH 3.0, in isotonic sodium chloride solution. The particle size of albumin, the zeta potential, the surface charge and fluorescent properties of BSA-surfactant composites were investigated concerning addition of increasing amount of surfactant. The thermal stability of the systems was monitored by calorimetric analysis (DSC). The formation of the well-ordered structure in the self-assembly process in liquid phase was studied by XRD measurement. The structure of the precipitated BSA-surfactant nanocomposites was characterized by small-angle X-ray scattering (SAXS). Finally, ibuprofen (IBU) molecules were enclosed in BSA-surfactant bioconjugate systems and the release properties of the drug were investigated. It has been found out that, as a consequence to the increasing number of carbon atoms in the alkyl chains of the surfactant, the structure and the fluorescent properties of the aggregates formed can be controlled due to the increase in the hydrophobicity of BSA-surfactant composites. The bioconjugates are well applicable as carrier to realize controlled release of drug molecules.

Self-assembling gradient copolymers of vinylimidazol and (acrylic)ibuprofen with anti-inflammatory and zinc chelating properties.

Novel gradient copolymers of hydrophilic 1-vinylimidazol and hydrophobic methacrylic derivative of ibuprofen prepared by free radical polymerization are described. The heterogeneous distribution of monomeric units along the polymeric chains leads to a gradient distribution of the hydrophobic and hydrophilic sequences responsible of nanoparticles formation through a self-assembling mechanism, capable of tune the water permeation due to the ionizable imidazole moieties and their gradient profile along the macromolecules, exhibiting pH and composition dependent effect in terms of diameter, zeta potential, acid-base buffering, ibuprofen release and chelating capacities, responsible of matrix metalloproteinase dysfunction showing anti-inflammatory activity in a nitric oxide inhibition assay.