Synthesis, characterization and stability of crosslinked chitosan-maltodextrin pH-sensitive nanogels

Area of Science:

• Biomaterials Science
• Nanotechnology
• Polymer Chemistry

Background:

• Polysaccharide-based nanogels are attractive due to biodegradability, biocompatibility, and responsiveness.
• Chitosan and maltodextrins are versatile polysaccharides for nanogel synthesis.

Purpose of the Study:

• To synthesize monodisperse, tunable, pH-sensitive nanogels using chitosan and partially oxidized maltodextrins.
• To characterize the nanogels' size, morphology, surface charge, and colloidal stability.
• To evaluate the pH-responsiveness and biocompatibility of the synthesized nanogels.

Main Methods:

• Reductive amination was used to crosslink chitosan and partially oxidized maltodextrins.
• Nanogel synthesis was performed in dilute and semi-dilute regimes of chitosan concentration.
• Nanoparticle characterization included size, ζ-potential, morphology (SEM/TEM), and stability studies.
• Cell viability assays using HEK293T cells assessed biocompatibility.

Main Results:

• Monodisperse nanogels with sizes ranging from 63 ± 9 to 279 ± 16 nm were synthesized.
• Nanogels exhibited quasi-spherical to cauliflower-like morphology and a ζ-potential of +36 ± 2 mV.
• Colloidal stability was maintained for up to 7 weeks; size and charge were tunable by oxidation degree and chitosan concentration.
• Significant pH-responsiveness was observed, with nanogel swelling and increased ζ-potential at lower pH.
• HEK293T cell viability assays confirmed the biocompatibility of the maltodextrin-chitosan nanogels.

Conclusions:

• Chitosan/maltodextrin nanogels can be successfully synthesized with tunable properties.
• The nanogels demonstrate pH-sensitivity, good colloidal stability, and biocompatibility.
• These findings highlight the potential of these nanogels for various biomedical applications.