Soft-matrices based on silk fibroin and alginate for tissue engineering.

Soft tissue regeneration requires the use of matrices that exhibit adequate mechanical properties as well as the ability to supply nutrients and oxygen, and to remove metabolic bio-products. In this work, we describe the development of hydrogels based on the blend between alginate (Alg) and silk fibroin (SF). Herein, we report two main strategies to combine cells with biomaterials: cells are either seeded onto prefabricated hydrogels films (2D), or encapsulated during hydrogel microcapsules formation (3D).

Hybrid hydrogels based on keratin and alginate for tissue engineering.

Novel hybrid hydrogels based on alginate and keratin were successfully produced for the first time. The self-assembly properties of keratin, and its ability to mimic the extracellular matrix were combined with the excellent chemical and mechanical stability and biocompatibility of alginate to produce 2D and 3D hybrid hydrogels. These hybrid hydrogels were prepared using two different approaches: sonication, to obtain 2D hydrogels, and a pressure-driven extrusion technique to produce 3D hydrogels.

Preparation of novel bioactive nano-calcium phosphate-hydrogel composites.

Nano-sized hydroxyapatite (nHA) and carbonate-substituted hydroxyapatite (nCHA) particles were incorporated into a poly-2-hydroxyethylmethacrylate/polycaprolactone (PHEMA/PCL) hydrogel at a filler content of 10 wt%. Fourier transform infrared absorption, transmission electron microscopy, x-ray diffraction and scanning electron microscopy were used to analyse the physical and chemical characteristics of the calcium phosphate fillers and resultant composites. Nano-sized calcium phosphate particles were produced with a needle-like morphology, average length of 50 nm and an aspect ratio of 3.

Biological control of apatite growth in simulated body fluid and human blood serum.

The surface transformation reactions of bioactive ceramics were studied in vitro in standard K9-SBF solution and in human blood serum (HBS)-containing simulated body fluid (SBF). The calcium phosphate ceramics used for this study were stoichiometric hydroxyapatite (HA), beta-tricalcium phosphate (beta-TCP) and brushite. Immersion of each calcium phosphate tested in this study, in simulated body fluid, led to immediate surface precipitation of apatite.