Chitosan/vanillin/polydimethylsiloxane scaffolds with tunable stiffness for muscle cell proliferation.

The mechanical properties of scaffolds can significantly influence cell behavior. We propose a methodology for producing chitosan and vanillin-crosslinked chitosan films with tunable mechanical properties to be applied as scaffolds for C2C12 myoblasts. In this approach, aqueous polydimethylsiloxane (PDMS) elastomeric dispersions were prepared using polysorbate 20 as emulsifier.

Vanillin crosslinked chitosan films: The states of water and the effect of carriers on curcumin uptake.

In this work, chitosan chains were crosslinked with different contents of vanillin (Van), characterized and loaded with curcumin (CUR), a hydrophobic drug. Sodium dodecyl sulfate (SDS), Tween 20® (T20) and β-cyclodextrin (βCD) were used as curcumin carriers. Films prepared with Van 20 % yielded gel content of 70 %, swelling degree of ~23 g/g, bound water and capillary water, as revealed by Time-Domain Nuclear Magnetic Resonance measurements.

Crosslinkers for polysaccharides and proteins: Synthesis conditions, mechanisms, and crosslinking efficiency, a review.

Polysaccharides and proteins are important macromolecules for developing hydrogels devoted to biomedical applications. Chemical hydrogels offer chemical, mechanical, and dimensional stability than physical hydrogels due to the chemical bonds among the chains mediated by crosslinkers. There are many crosslinkers to synthesize polysaccharides and proteins based on hydrogels.

Surface Chemistry Studies on the Formation of Mixed Stearic Acid/Phenylalanine Dehydrogenase Langmuir and Langmuir-Blodgett Films.

This work investigates the physicochemical properties of mixed stearic acid (HSt)/phenylalanine dehydrogenase enzyme (PheDH) Langmuir films and their immobilization onto solid supports as Langmuir-Blodgett (LB) films. PheDH from the aqueous subphase enters the surfactant matrix up to an exclusion surface pressure of 25.3 mN/m, leading to the formation of stable and highly condensed mixed Langmuir monolayers.

Study of the interactions of gold nanoparticles functionalized with aminolevulinic acid in membrane models.

Gold nanoparticles have been intensively studied in cancer therapy to improve drug release, increasing therapeutic action and reducing adverse effects. The interaction between gold nanoparticles and cell membranes can give information about the cell internalization. In this study, gold nanoparticles with aminolevulinic acid (5-ALA) were synthesized using the photoreduction method (5-ALA: AuNPs).

Conjugated polymers as Langmuir and Langmuir-Blodgett films: Challenges and applications in nanostructured devices.

Initially developed for classic systems composed of fatty acids and phospholipids, the Langmuir and Langmuir-Blodgett (LB) techniques allow the fabrication of nanometer-scale devices at self-assembly interfaces with high control over the thickness and molecular architecture. Their application in the research and production of new plastic materials has grown considerably over the past few decades due to the efficiency of conjugated polymers (CPs) for the production of light-emitting diodes, flexible displays, solar cells, and other photoelectronic devices. The structuring of polymers at different interfaces is not trivial as this class of macromolecules can undergo through different processes of folding/unfolding, which hinders the formation of stable Langmuir monolayers and, consequently, the production of Langmuir-Blodgett films.

Interaction of dicentrinone, an antitrypanosomal aporphine alkaloid isolated from Ocotea puberula (Lauraceae), in cell membrane models at the air-water interface.

In the present work, the oxoaporphine alkaloid dicentrinone was isolated, for the first time, from leaves of Ocotea puberula (Lauraceae). This alkaloid exhibited antiparasitic activity against trypomastigote forms of Trypanosoma cruzi (IC of 16.4 ± 1.

Tyrosinase enzyme Langmuir monolayer: Surface chemistry and spectroscopic study.

This study investigates the surface chemistry properties of the tyrosinase enzyme Langmuir monolayer at air-aqueous interface using sodium chloride in the subphase to induce the surface activity of the enzyme. Investigation of surface packing and stability of the tyrosinase Langmuir monolayer were performed using surface chemistry experiments while spectroscopic analysis was done to study enzyme conformation. It was found that the tyrosinase enzyme forms a fluid film at air-aqueous interface with good stability as shown by compression-decompression cycles experiments and stability measurements at various surface pressures.

Surface chemistry and spectroscopic studies of the native phenylalanine dehydrogenase Langmuir monolayer at the air/aqueous NaCl interface.

This study investigates the main aspects of the surface behavior of the native phenylalanine dehydrogenase (PheDH) enzyme at the air/aqueous interface employing a saline subphase to induce the enzyme surface activity. Surface chemistry experiments were performed in order to determine the surface packing and stability of the formed layer, while spectroscopic experiments provided information regarding its secondary structure conformation. It was found that the PheDH enzyme forms a fluid film, which is quite homogeneous throughout its entire compression, being stable for long periods of time with no significant evidence of aggregates or irreversible domains during interfacial compression/decompression processes.