Core–Shell Spheroidal Hydrogels Produced via Charge-Driven Interfacial Complexation

Abstract

Through charge-driven interfacial complexation, we produced millimeter-sized spheroidal hydrogels (SH) with a core–shell structure allowing long-term stability in aqueous media. The SH were fabricated by extruding, dropwise, a cationic cellulose nanofibril (CCNF) dispersion into an oppositely charged poly­(acrylic acid) (PAA) bath. The SH have a solid-like CCNF–PAA shell, acting as a semipermeable membrane, and a liquid-like CCNF suspension in the core. Swelling behavior of the SH was dependent on the osmotic pressure of the aging media. Swelling could be suppressed by increasing the ionic strength of the media as this enhanced interfibrillar interactions and thus strengthened the outer gel membrane. We further validated a potential application of SH as reusable matrixes for glucose oxidase (GOx) entrapment, where the SH work as microreactors from which substrate and product are freely able to migrate through the SH shell while avoiding enzyme leakage.

Structure–function relationships in polymeric multilayer capsules designed for cancer drug delivery

“…Multilayer capsules represent multi-purpose containers that can be used in biomedical applications, including controlled targeted delivery, [1][2][3] theranostics, 4 sensing, [5][6][7][8] microreactors, 9 nanophotonics, and imaging. 10,11 The approaches to the preparation of multilayer structures include traditional techniques, such as layer-by-layer assembly, 12 as well as the novel and more technologically advanced fluidic approach, 13,14 emulsion, 15 fluidized-bed coating, [16][17][18] ultrasonic atomization, 19 and electro-spraying. 20 The assembly of the multilayer capsules is based on coating various templates with polymers.…”

“…The approaches to the preparation of multilayer structures include traditional techniques, such as layer-by-layer assembly, 12 as well as the novel and more technologically advanced fluidic approach, 13,14 emulsion, 15 fluidized-bed coating, 16–18 ultrasonic atomization, 19 and electro-spraying. 20 The assembly of the multilayer capsules is based on coating various templates with polymers.…”

Enzyme-Functionalized Cellulose Beads as a Promising Antimicrobial Material

“… 20 The presence of hydroxyl moieties in cellulose can be used to add functional groups able to make the immobilization of GOx feasible. 21 , 22 Periodate mediated cellulose oxidation generates aldehyde moieties that can be used to bind the enzyme lysines via imine formation, also known as a Schiff base. 20 This well-established binding method has been used for the immobilization of proteins and enzymes on cellulose-based materials.…”

“…The use of cellulose as a support (both native and derivatized) for enzyme immobilization has been well established in a wide range of biomedical applications, owing to its biodegradability, low cost, and biocompatibility . The presence of hydroxyl moieties in cellulose can be used to add functional groups able to make the immobilization of GOx feasible. , Periodate mediated cellulose oxidation generates aldehyde moieties that can be used to bind the enzyme lysines via imine formation, also known as a Schiff base . This well-established binding method has been used for the immobilization of proteins and enzymes on cellulose-based materials. − The general approach to the creation of the GOx-functionalized beads herein used is shown in Scheme .…”