Nanofibrous gelatin–silica hybrid scaffolds mimicking the native extracellular matrix (ECM) using thermally induced phase separation

Abstract

We herein propose a novel way of producing nanofibrous gelatin-silica hybrid scaffolds through thermally induced phase-separation (TIPS) particularly using mixtures of gelatin solution and silica sol, which can mimic the physical structure, chemical composition, and eventually functions of the native bone extracellular matrix (ECM). The gelatin solutions were homogeneously hybridized with various contents of a silica sol using simple magnetic stirring, which enabled the construction of a nanofibrous structure with a uniform distribution of the silica in the gelatin nanofibers. The nanofibrous gelatinsilica hybrid scaffolds showed much better mechanical properties and in vitro biodegradation stability and apatite-forming ability than the nanofibrous pure gelatin scaffold, which were achieved by the presence of a stiff, bioactive silica phase in the nanofibers and the interaction between the silica hydroxyls and the amino group in the gelatin polymer. In addition, the nanofibrous gelatin-silica hybrid scaffold with a silica content of 30 wt% showed reasonably high in vitro biocompatibility. These findings suggest that the highly porous, nanofibrous hybrid structure mimicking the bone ECM can provide an excellent matrix for bone tissue regeneration.

Porous gelatin–siloxane hybrid scaffolds with biomimetic structure and properties for bone tissue regeneration

“…13 After 1 and 5 days of cell culturing, the samples were transferred to new mutiwell culture plates and then washed by PBS, which was followed by reaction with the MTS solution for 4 h. The quantity of the formazan product, which would be directly proportional to the number of living cells in the culture, was measured by the absorbance at 490 nm using a microplate reader (Model 550; Biorad, Hercules, CA). At least four species for each condition were tested to obtain mean and standard deviation.…”

Untitled

“…[40] This structure was achieved by the unique phase separation of the gelatin/silica hybrid mixtures during TIPS at -70°C. [41] The porous structure is strongly affected by the additional variable not considered here, such as non-solvent/solvent ratio, polymer concentration, and temperature. [42] The hydrated gelatin nanoparticles have smooth surfaces and have roughly spherical in shape were observed in earlier studies.…”

Biomaterials control of pluripotent stem cell fate for regenerative therapy

“…However, the line-ofsight process creates a very thin membrane structure, which is thus considered 'pseudo-3D' (rather than 'exactly 3D') structure, holding some limitations in completely mimicking the native 3D architecture and in progressive cellular penetration [176][177][178][179]188]. Even so, the electrospun nanofibers have been potentially used to cultivate stem cells to provide ECM mimic matrix and to interpret the cellular interactions with the underlying ECM-like nanostructure [185,189,190]. Furthermore, owing to the ultrathin nanofibrous network, the electrospun scaffold can possess very low rigidity (stiffness) providing a sufficient flexibility for cells to sense the mechanical elasticity; albeit its preformed nature, this is different from the case of other scaffolds, like solid foamed or microfiber networked ones, offering a matrix platform suitable for the PSC culture.…”