Microporous Polymeric 3D Scaffolds Templated by the Layer‐by‐Layer Self‐Assembly

Abstract

Polymeric scaffolds serve as valuable supports for biological cells since they offer essential features for guiding cellular organization and tissue development. The main challenges for scaffold fabrication are i) to tune an internal structure and ii) to load bio-molecules such as growth factors and control their local concentration and distribution. Here, a new approach for the design of hollow polymeric scaffolds using porous CaCO3 particles (cores) as templates is presented. The cores packed into a microfluidic channel are coated with polymers employing the layer-by-layer (LbL) technique. Subsequent core elimination at mild conditions results in formation of the scaffold composed of interconnected hollow polymer microspheres. The size of the cores determines the feature dimensions and, as a consequence, governs cellular adhesion: for 3T3 fibroblasts an optimal microsphere size is 12 μm. By making use of the carrier properties of the porous CaCO3 cores, the microspheres are loaded with BSA as a model protein. The scaffolds developed here may also be well suited for the localized release of bio-molecules using external triggers such as IR-light.

Protein loading into porous CaCO3microspheres: adsorption equilibrium and bioactivity retention

“…1, the microspheres show a highly developed porous internal structure. 16 The zeta-potential of CaCO 3 microspheres in 0.05 M glycine buffer at pH 9.0 was found to be slightly positive (5.0 AE 0.3 mV), which might be due to the closeness to the pI. As reported in a previous study, 14 the average specific surface area of the microspheres is 8.8 m 2 g À1 , their density is 1.6 g cm À3 , and the average pore size is in the range 20-60 nm.…”

“…15,16 Briefly, 3 mL of 1 M Na 2 CO 3 solutions were rapidly added to 9 mL of H 2 O and 3 mL of 1 M CaCl 2 and thoroughly agitated on a magnetic stirrer (650 rpm) for 45 s at 20 1C. 15,16 Briefly, 3 mL of 1 M Na 2 CO 3 solutions were rapidly added to 9 mL of H 2 O and 3 mL of 1 M CaCl 2 and thoroughly agitated on a magnetic stirrer (650 rpm) for 45 s at 20 1C.…”

“…3,5,[10][11][12][13] Pulmonary delivery is envisaged in this case. 16,17 Another important feature of the microspheres is that they are mesoporous. 14,15 Together with easy preparation procedure and low costs these microspheres are biocompatible and can be eliminated by mild conditions such as slightly acidic pH or EDTA.…”

The mechanism of catalase loading into porous vaterite CaCO3 crystals by co-synthesis

“…A high loading of proteins into the crystals will also ensure a high loading capacity for the carriers assembled using the crystal. We note that other applications of the crystals including sensors 67,68 or self-assembled tailor-made polymer macrostructures such as scaffolds [69][70][71] have been reported.…”

Controllable Aligned Nanofiber Hybrid Yarns with Enhanced Bioproperties for Tissue Engineering

“…For example, skeletal muscle tissue is composed of aligned myofibers, and blood vessel is made up of aligned vascular endothelial cells along the axial direction. Various methods such as freeze‐drying, molecular self‐assembly, photo‐lithography, micro‐grooving, and 3D printing have been employed for the preparation of 3D well‐organized tissue scaffolds. However, in clinical and commercial considerations, these methods involve complex process, expensive cost, or low resolution, and are difficult to adapt to the complexity of the size, configuration, and strength of the target tissue/organ.…”