Nanocellulose/Gelatin Composite Cryogels for Controlled Drug Release

Abstract

Nanocellulose/gelatin composite cryogels with controllable porosity, reversible network structure and good biocompatibility were constructed via the chemical cross-linking of dialdehyde starch and further used as the carriers for controlled 5-fluorouracil (5-FU) release. The pore structure of the composite cryogels was successfully tuned by changing the dosages and ratios of nanofibrillated cellulose (NFC), gelatin and dialdehyde starch. Under the same density of cryogels, increasing the NFC content results in higher specific surface area and porosity. The swelling ratios first increase and then decrease with an increase in the contents of NFC and dialdehyde starch, and the swelling ratios of cryogels are relatively higher in neutral medium than those in acidic medium. The drug loading improvement is favored by increasing the NFC content and cross-linking degree. The drug-loaded cryogels show controllable and sustained release of 5-FU in vitro, which is attributed to the hydration of gelatin and reversible hydrolysis of acetal/hemiacetal. The behaviors of drug release are dependent on the structures of cryogels including the NFC/gelation ratio, density and cross-linking degree as well as the pH values. The sustained release time of the cryogel carrier is able to reach 12 h in a simulated intestinal environment.

Thermally Conductive and Electrical Insulation BNNS/CNF Aerogel Nano-Paper

“…CNF was prepared according to previous work [31,32]. Five grams of bleached softwood pulp with mechanical pretreatment was suspended in 450 mL of deionized water and 50 mL of NaClO.…”

Biodegradable super porous inulin cryogels as potential drug carrier

“…As biopolymeric materials from natural sources demonstrate great potential in biomedical, pharmaceutical, and environmental applications due to their biocompatible, biodegradable and non‐toxic structures. To the best of our knowledge, the synthesis of cryogel from natural polymers in the literature is very new and there only are few studies on cryogels from natural polymers 17,21,24,26 . To the best of our knowledge this is the first report for the synthesis and characterization of Inulin cryogels in the literature.…”

“…For example, Demirci et al, reported the use of HA and HA based cryogel composites with polyethyleneimine and Halloysite nanotubes for sodium diclofenac (SDF) drug release studies and found that 31% to 87% of the loaded SDF was released in 20 hours 17 . In another study, Li et al; reported the cross‐linked nano fibrillated cellulose/gelatin (NFC) composite cryogels for 5‐FU, a cancer drug release studies via physical embedding this drug into cryogels due to hydrogen bond interaction 26 . And, the authors reported that the cumulative release of 5‐FU from the cryogels was close to 100% after 12 hours 26 .…”

“…In another study, Li et al; reported the cross‐linked nano fibrillated cellulose/gelatin (NFC) composite cryogels for 5‐FU, a cancer drug release studies via physical embedding this drug into cryogels due to hydrogen bond interaction 26 . And, the authors reported that the cumulative release of 5‐FU from the cryogels was close to 100% after 12 hours 26 . Therefore, in comparison to similar studies reported in the literature, the use of inulin cryogels as a drug delivery system afford some advantages as it can be designed to degrade in a controllable manner and release certain amount of the loaded drug depending of the medium pH and the used amount of crosslinker.…”

“…The size and the extent of pores in cryogels can be controlled by various parameters, for example, the amount of water, cooling rate, the reaction temperature, monomer/polymer concentration, the amount of crosslinker, the amount of catalyst, etc 17‐21 . Ascryogels exhibit faster response time and mechanical strength compared to normal hydrogels, they offer many advantages in common applications including environmentally related, that is, separation, actuation, and sensors, tissue engineering and as cell carrier in biotechnology due to their super‐porous structures 22‐27 . Moreover, because it is possible to prepare cryogels from natural sources and they are biodegradable, they can be used in many biomedicinally relevant fields such as for in‐vitro drug delivery, cell carrier, cell culture applications and so on.…”