Assessment of synergistic interactions on self-assembled sodium alginate/nano-hydroxyapatite composites: to the conception of new bone tissue dressings

The aim of this work is to assess the behavior of biocomposites (CPSs) in regard to the generation of biogenic hydroxyapatite and also their degradation depending on the concentration of cross-linker agent, pH, and ionic strength. The development of these composites with potential application in bone tissue regeneration is based on alginate and synthetic nano-hydroxyapatite (nano-HA), which was used as a cross-linker agent. The CPSs showed the capability to develop biogenic hydroxyapatite when they were incubated in simulated body fluid (SBF) depending on the incubation time and concentration of the linker. These results were analyzed by x-ray diffraction (XRD), Fourier transform infrared (FT-IR), and scanning electron microscopy (SEM). Furthermore, the CPSs have shown resistance to the degradation (demonstrated by swelling and dissolution tests) when the mentioned conditions were modified. Finally, the development of a liquid crystalline phase within the composites, which contributes to reinforce their structure, is a novel finding in this study. This behavior has been shown by means of optical microscopy (OM) with crossed polaroids. Thus, these composites displayed promising results to be used as bone filling materials in the future.