Studies of in situ‐forming hydrogels by blending PLA‐PEG‐PLA copolymer with silk fibroin solution

Abstract

Hydrogels had been prepared by blending PLA-PEG-PLA copolymer with Bombyx mori silk fibroin (SF) solution. Copolymers were synthesized by ring opening polymerization of L-lactide in the presence of dihydroxyl PEG with molar mass of 400 and 1000, and characterized by using (1)H NMR and DSC. Hydrogels formed leaf-like lamellar structures with many nanoglobules which may reserve drugs or growth factors more effectively. Rheological measurements indicated that the adding of copolymer significantly accelerated the hydrogelation of silk fibroin solution which leads to orders-of-magnitude increase in the complex shear modulus to form rigid hydrogel. Hydrogelation kinetics could be controlled easily by changing the concentration ratio, kinds of copolymer and hydrogelation temperature, suggesting the hydrogels could be formed in situ under physiological conditions with suitable mechanical properties. Furthermore, Fourier transform infrared, X-ray diffraction, and differential thermal analysis were employed to study the structure of hydrogels. The copolymer and SF in blend hydrogels were phase separation. There was an increase of β-sheet content and formation of silk II structure during hydrogelation. These results may indicate that copolymer/SF hydrogels could be a valuable candidate scaffold as in situ-forming hydrogels for drug/growth factor release in tissue engineering.

Hydrogel-Based Controlled Release Formulations: Designing Considerations, Characterization Techniques and Applications

“…The thermal profiles of the gels may be studied using a differential thermal analyzer (DTA) and a differential scanning calorimeter (DSC) [180] . The thermal profile of a material may be obtained either during the heating, the cooling or a combination of both cycles.…”

Injectable silk-polyethylene glycol hydrogels

“…This strategy, however, cannot be easily used for naturally derived biopolymers without chemical modification to link specific reactive groups on the polymer chains. Silk fibroin forms hydrogels when the solution was mixed with acids, salts, alcohols, surfactants and polymers [12][13][14][15]. However, toxicity of these chemicals is a significant concern for medical applications.…”

Potential of biocompatible regenerated silk fibroin/sodium N-lauroyl sarcosinate hydrogels

“…For each type, a minimum of six samples were measured and the OD values were averaged to determine the progression of the OD changes with time. [18,19,[23][24][25][26] The gelation of the mixed solution was non-instantaneous, requiring some time before changes in OD were observed. The time required to reach the point at which the most rapid OD changes were observed was regarded as the corresponding GT.…”