Double-Network Hydrogel Films Based on Cellulose Derivatives and κ-Carrageenan with Enhanced Mechanical Strength and Superabsorbent Properties.

Covalently crosslinked sodium carboxymethyl cellulose (CMC)-hydroxyethyl cellulose (HEC) hydrogel films were prepared using citric acid (CA) as the crosslinking agent. Thereafter, the physically crosslinked κ-carrageenan (κ-CG) polymer was introduced into the CMC-HEC hydrogel structure, yielding κ-CG/CMC-HEC double network (DN) hydrogels. The κ-CG physical network provided sacrificial bonding, which effectively dissipated the stretching energy, resulting in an increase in the tensile modulus, tensile strength, and fracture energy of the DN hydrogels by 459%, 305%, and 398%, respectively, compared with those of the CMC-HEC single network (SN) hydrogel.

Alginate-reinforced poly(3-hydroxybutyrate)/ poly(hydroxybutyrate-co-hydroxyvalerate) aerogel monoliths fabricated by phase separation as environmental floating adsorbents.

Poly(3-hydroxybutyrate) (PHB)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) aerogel monoliths were prepared via nonsolvent induced phase separation and then sequentially immersed in ethanol and sodium alginate (ALG) solutions. The resulting composite aerogels contained up to a 52 wt% fraction ALG, causing a remarkable increase in their compressive modulus and collapse strength from 0.3 MPa and 33 kPa to 4 MPa and 406 kPa, respectively, i.

Chitosan-reinforced PHB hydrogel and aerogel monoliths fabricated by phase separation with the solvent-exchange method.

The poly(3-hydroxybutyrate) (PHB) organogel monoliths were prepared by nonsolvent-induced phase separation (NIPS). The NIPS-derived organogels were solvent-exchanged with chitosan (CS) solution, resulting in the successful loading of CS into PHB hydrogel. With increasing the CS content, the as-prepared composite hydrogels became syringe injectable with excellent thixotropy due to the increase in the gel network's hydrophilicity.

Chitosan-dipeptide hydrogels as potential anticancer drug delivery systems.

A novel chitosan-dipeptide hydrogel was fabricated through a combination of self-assembly of 9-fluorenylmethoxycarbonyl-modified diphenylalanine (Fmoc-FF) and its electrostatic interaction with glycol chitosan (GCS). Hydrogel strength and stability depended on its composition. The highest gel strength was observed at a Fmoc-FF mass fraction (ϕ) of 0.

Nonsolvent-induced phase separation of poly(3-hydroxybutyrate) and poly(hydroxybutyrate-co-hydroxyvalerate) blend as a facile platform to fabricate versatile nanofiber gels: Aero-, hydro-, and oleogels.

We demonstrated a strategy to prepare different types of 3-D nanofibrous polymeric gels, including hydro-, aero-, and oleogels by nonsolvent-induced phase separation (NIPS). NIPS-derived gel monoliths of poly(3-hydroxybutyrate) (PHB) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) blends were converted into hydrogels and aerogels by solvent exchange and freeze-drying, respectively. The high hydrophobicity and porosity of the nanofibrous PHB/PHBV aerogels enabled them to absorb various oils and swell to 20-30 times their own weight.

Nanofibrous Foams of Poly(3-hydroxybutyrate)/Cellulose Nanocrystal Composite Fabricated Using Nonsolvent-Induced Phase Separation.

In this study, we fabricated nanofibrous foams of neat poly(3-hydroxybutyrate) (PHB) and PHB/cellulose nanocrystal (CNC) nanocomposite using nonsolvent-induced phase separation (NIPS) followed by solvent extraction. Two different nonsolvents, tetrahydrofuran (THF) and 1,4-dioxane (Diox), in combination with the solvent, chloroform (CF), were used for NIPS. The parameters of NIPS-derived crystallization kinetics were calculated using Avrami analysis of time-dependent infrared spectral measurements.

Porous Poly(3-hydroxybutyrate) Scaffolds Prepared by Non-Solvent-Induced Phase Separation for Tissue Engineering.

Unlabelled: Highly porous poly(3-hydroxybutyrate) (PHB) scaffolds were fabricated using non-solvent-induced phase separation with chloroform as the solvent and tetrahydrofuran as the non-solvent. The microporosity, nanofiber morphology, and mechanical strength of the scaffolds were adjusted by varying the fabrication parameters, such as the polymer concentration and solvent composition. The influence of these parameters on the structure and morphology of PHB organogels and scaffolds was elucidated using small-angle neutron scattering and scanning electron microscopy.

PAMAM dendrimers as potential agents against fibrillation of alpha-synuclein, a Parkinson's disease-related protein.

The effect of PAMAM dendrimers (generations G3, G4 and G5) on the fibrillation of alpha-synuclein was examined by fluorescence and CD spectroscopy, TEM and SANS. PAMAM dendrimers inhibited fibrillation of alpha-synuclein and this effect increased both with generation number and PAMAM concentration. SANS showed structural changes in the formed aggregates of alpha-synuclein--from cylindrical to dense three-dimensional ones--as the PAMAM concentration increased, on account of the inhibitory effect.