Synthesis and Exfoliation of Calcium Organophosphonates for Tailoring Rheological Properties of Sodium Alginate Solutions: A Path toward Polysaccharide-Based Bioink

Layered nanoparticles with surface charge are exploredas rheologicalmodifiers for extrudable materials, utilizing their ability to induceelectrostatic repulsion and create a house-of-cards structure. Thesenanoparticles provide mechanical support to the polymer matrix, resultingin increased viscosity and storage modulus. Moreover, their advantageousaspect ratio allows for shear-induced orientation and decreased viscosityduring flow. In this work, we present a synthesis and liquid-basedexfoliation procedure of phenylphosphonate-phosphate particleswith enhanced ability to be intercalated by hydrophilic polymers.These layered nanoparticles are then tested as rheological modifiersof sodium alginate. The effective rheological modification is provedas the viscosity increases from 10(1) up to 10(3) Pa center dot s in steady state. Also, shear-thinning behavior is observed.The resulting nanocomposite hydrogels show potential as an extrudablebioink for 3D printing in tissue engineering and other biomedicalapplications, with good shape fidelity, nontoxicity, and satisfactorycell viability confirmed through encapsulation and printing of mousefibroblasts.