Nanogels based on alginic aldehyde and gelatin by inverse miniemulsion technique: synthesis and characterization

• Nanoscopic counterparts of alginic aldehyde–gelatin hydrogels were prepared by an inverse miniemulsion technique.
• Cross-linking between alginic aldehyde and gelatin occurred due to Schiff's base reaction.
• The spherical nanogel particles were redispersed in water without the use of additional surfactant.
• Hemocompatibility and cytotoxicity analyses proved the compatibility of the nanogels for biomedical applications.

Nanogels were developed from alginic aldehyde and gelatin by an inverse miniemulsion technique. Stable inverse miniemulsions were prepared by sonication of noncontinuous aqueous phase (mixture of alginic aldehyde and gelatin) in a continuous organic phase (Span 20 dissolved in cyclohexane). Cross-linking occurred between alginic aldehyde (AA) and gelatin (gel) in the presence of borax by Schiff's base reaction during the formation of inverse miniemulsion. The effects of surfactant (Span 20) concentration, volume of the aqueous phase and AA/gel weight ratio on the size of the alginic aldehyde–gelatin (AA–gel) nanoparticles were studied. Nanogels were characterized by DLS, FT-IR spectroscopy, TGA, SEM and TEM. DLS, TEM and SEM studies demonstrated nanosize and spherical morphology of the nanogels. Hemocompatibility and in vitro cytocompatibility analyses of the nanogels proved their nontoxicity. The results indicated the potential of the present nanogel system as a candidate for drug- and gene-delivery applications.