Porous aligned ZnSr-doped β-TCP/silk fibroin scaffolds using ice-templating method for bone tissue engineering applications

Abstract

The bone is a complex and dynamic structure subjected to constant stress and remodeling. Due to the worldwide incidence of bone disorders, tissue scaffolds and engineered bone tissues have emerged as solutions for bone grafting, which require sophisticated scaffolding architectures while keeping high mechanical performance. However, the conjugation of a bone-like scaffold architecture with efficient mechanical properties is still a critical challenge for biomedical applications. In this sense, the present study focused on the modulating the architecture of silk fibroin (SF) scaffolds crosslinked with horseradish peroxidase and mixed with zinc (Zn) and strontium (Sr)-doped β-tricalcium phosphate (ZnSr.TCP) to mimic bone structures. The ZnSr.TCP-SF hydrogels were tuned by programmable ice-templating parameters, and further freeze-dried, in order to obtain 3D scaffolds with controlled pore orientation. The results showed interconnected channels in the ZnSr.TCP-SF scaffolds that mimic the porous network of the native subchondral bone matrix. The architecture of the scaffolds was characterized by microCT, showing tunable pore size according to freezing temperatures (-196 ºC: ~80.2 ± 20.5 µm; -80 ºC:~73.1 ± 20.5 µm; -20 ºC: ~104.7 ± 33.7 µm). The swelling ratio, weight loss, and rheological properties were also assessed, revealing efficient scaffold integrity and morphology after aqueous immersion. Thus, the ZnSr.TCP-SF scaffolds made of aligned porous structure were developed as affordable candidates for future applications in clinical osteoregeneration and in vitro bone tissue modelling.

Anisotropic silk nanofiber layers as regulators of angiogenesis for optimized bone regeneration

“…Silk fibroin (SF) biomaterials are promising bone regenerative matrices due to the biocompatibility, excellent and tunable mechanical properties, and ease of materials fabrication [ [9] , [10] , [11] , [12] ]. SF-based scaffolds, films and hydrogels have been developed to repair various bone defects [ 9 , [13] , [14] , [15] ].…”

3D printed strontium–zinc-phosphate bioceramic scaffolds with multiple biological functions for bone tissue regeneration

“…Although other scaffold fabrication methods such as the freeze-drying method can also create interconnected and oriented pores, the pore controllability is far away from 3D printing. 27 The in vitro degeneration experiment showed a much faster weight loss and ion release rate in SZP scaffolds as compared to β-TCP scaffolds (Fig. 2 and Fig.…”

3DICE coding matrix multidirectional macro-architecture modulates cell organization, shape, and co-cultures endothelization network

“…The ice-templating technique has been previously used for the 3D fabrication of homogeneous aligned porous structures [24] [-] [26]. While low thermal conductivity molds ensure directional freezing [27], the use of high thermally conductive molds induces radial ice growth towards the mold [28]. However, the desired multidirectional architectures composed of continuous linear and radial porous zones have not been successfully developed so far, making the state-of-the-art about ice-templating technique quite limited.…”