Gelation Process and Physicochemical Properties of Thai Silk Fibroin Hydrogels Induced by Various Anionic Surfactants for Controlled Release of Curcumin

Abstract

Hydrogels based on Thai silk fibroin (SF) were prepared by the induction of various anionic surfactants including sodium octyl sulfate (SOS), sodium dodecyl sulfate (SDS), and sodium tetradecyl sulfate (STS), which have a similar chemical structure but different alkyl chain lengths and charges. The effects of anionic surfactant types and their concentrations on the gelation mechanism and time of SF were systematically investigated. We found that SDS and STS that have long alkyl chain lengths and high negative charges could accelerate the gelation of SF to occur within 14–42 min in a concentration‐dependent manner. SOS that has a short alkyl chain length and low negative charge slowly induced SF to gel at around 113–144 h. The mechanisms of SF gelation induced by these three anionic surfactants were supposed to be combination of hydrophobic and electrostatic interactions, as well as the self‐transition of beta sheets. The SF + STS hydrogels were further employed to encapsulate curcumin for the controlled release application. The SF + 0.09% wt. STS hydrogel encapsulating curcumin showed a slow rate of degradation while sustained the release of curcumin. This hydrogel can be applied as a minimal invasive injectable hydrogel or as a hydrogel for topical treatment of diseases.

Exploring the Gelation Mechanisms and Cytocompatibility of Gold (III)-Mediated Regenerated and Thiolated Silk Fibroin Hydrogels

“…Indeed, a short gelation time is crucial for many applications, such as cell-loaded hydrogels or injectable controlled release systems. Crosslinking agents (e.g., glutaraldehyde, carbodiimides, or genipin), enzymes (e.g., tyrosinase or peroxidase), physical methods (e.g., vortexing or sonication), or chemical additives (e.g., alcohols [4], surfactants [5], or phospholipids [6]) have been applied to control the kinetics of SF gelation [7].…”

Comparative Study of Silk Fibroin-Based Hydrogels and Their Potential as Material for 3-Dimensional (3D) Printing

“…This gelation processes takes over two weeks, which is not practicable for the applications as cell-encapsulated bioink or injectable hydrogels. To reduce the gelation time, some amphipathic chemicals, such as surfactants and phospholipids were added into SF solution [ 25 , 26 ]. It can enhance the formation of β-sheet structure due to electrostatic and hydrophobic interactions.…”

“…Three formulations of SF hydrogels including natural gelation (SF/self-gelled), STS-induced (SF/STS) and DMPG-induced (SF/DMPG) were prepared according to the methods reported in our previous researches with slight modifications ( Table 1 ) [ 25 , 26 ]. The SF solution was loaded in the syringe and the hydrogel was formed within the syringe used for 3D-printing.…”

“…Moreover, photopolymerization, and the chemical crosslinkers, such as carbodiimides, glutaraldehyde, or genipin were used. Our previous studies demonstrated various formulations of SF-based hydrogels that can be induced by different agents, such as alcohols [ 24 ], an anionic surfactant, sodium tetradecyl sulfate (STS) [ 25 ], and a phospholipid 1,2-dimyristoyl- sn -glycerol-3-phospho-(1′- rac -glycerol) (DMPG) [ 26 ]. STS is as anionic surfactant that have been shown to accelerate the gelation of SF rather than the cationic and nonionic surfactant.…”

Bio-fabrication of stem-cell-incorporated corneal epithelial and stromal equivalents from silk fibroin and gelatin-based biomaterial for canine corneal regeneration

“…Impurities were removed by centrifugation at 9,000 rpm (approximately 12,700 g) at 4˚C for 20 min, twice. The obtained SF solution ranged from 6-7% w/w [25,26].…”