Mineralized Microgels via Electrohydrodynamic Atomization: Optimization and In Vitro Model for Dentin–Pulp Complex

Abstract

There is growing interest in the use of micro-sized hydrogels, including bioactive signals, as efficient platforms for tissue regeneration because they are able to mimic cell niche structure and selected functionalities. Herein, it is proposed to optimize bioactive composite microgels via electrohydrodynamic atomization (EHDA) to regenerate the dentin–pulp complex. The addition of disodium phosphate (Na2HPO4) salts as mineral precursors triggered an in situ reaction with divalent ions in solution, thus promoting the encapsulation of different amounts of apatite-like phases. Morphological analysis via image analysis of optical images confirmed a narrow distribution of perfectly rounded particles, with an average diameter ranging from 223 ± 18 μm to 502 ± 64 μm as a function of mineral content and process parameters used. FTIR, TEM, and EDAX analyses confirmed the formation of calcium phosphates with a characteristic Ca/P ratio close to 1.67 and a needle-like crystal shape. In vitro studies—using dental pulp stem cells (DPSCs) in crown sections of natural teeth slices—showed an increase in cell viability until 14 days, recording a decay of proliferation at 21 days, independent on the mineral amount, suggesting that differentiation is started, as confirmed by the increase of ALP activity at 14 days. In this view, mineralized microgels could be successfully used to support in vitro osteogenesis, working as an interesting model to study dental tissue regeneration.

Designing Advanced Drug Delivery Systems: Core-Shell Alginate Particles through Electro-Fluid Dynamic Atomization

“…The formed droplets are collected into a crosslinking bath (i.e., CaCl 2 ) to allow their ionic gelation to finally obtain spherical beads of homogeneous size prior to reaching the excess of charge on the droplet surface [ 25 ]. The processing of ionotropic polymers as alginates allows for the entrapment of cells, active molecules, and/or pharmaceutical species to form chemically functionalized carriers suitable for differently addressing the biological response [ 25 , 26 ]. Morphology and particle sizes can be highly adjusted by accurately setting process parameters (i.e., polymer concentration, voltage applied, needle diameter, working distance) [ 27 , 28 ].…”

Designing Advanced Drug Delivery Systems: Core-Shell Alginate Particles through Electro-Fluid Dynamic Atomization

“…The formed droplets are collected into a crosslinking bath (i.e., CaCl2), to allow their ionic gelation to finally obtain spherical beads with homogeneous size prior to reach the excess of charge on the droplet surface [26,27]. The processing of ionotropic polymers as alginates allows for the entrapment of cells, active molecules and/or pharmaceutical species to form chemically functionalized carriers suitable to differently address the biological response [27,28]. Morphology and particle sizes can be highly adjusted by accurately setting process parameters (i.e., polymer concentration, voltage applied, needle diameter, working distance) [29,30].…”