Bioadhesive Microporous Architectures by Self-Assembling Polydopamine Microcapsules for Biomedical Applications

Abstract

Bioadhesive microporous architectures that mimic the functions of a natural extracellular matrix (ECM) were prepared by self-assembling polydopamine (PDA) microcapsules, which not only favor cell adhesion and growth, but also facilitate growth factor immobilization and release. PDA-coated polystyrene (PS) microspheres are synthesized by polymerization of dopamine on sulfonated PS microspheres and then assembled using positively charged chitosan (CHI) layers as link agents. After the PS core templates were removed, microporous architectures composed of PDA microcapsules were obtained. The produced microporous PDA architectures have a high capability of adsorbing BMP-2 and realize the sustained release of BMP-2. More importantly, the bioadhesive micro architecture and its immobilized BMP-2 synergistically enhance the activity and osteogenetic differentiation of bone marrow mesenchymal stem cells (BMSCs). Both supercell adhesion and BMP-2 immobilization ability of these architectures are attributed to the intrinsic adhesive nature of PDA and the porous architectures via the assembly of PDA microcapsules. The bioadhesive microporous PDA architectures with both cell affinitive and GF release features have a great potential to mimic natural ECM for modifying various medical devices in the fields of tissue engineering and regenerative medicine.

Electroresponsive and cell-affinitive polydopamine/polypyrrole composite microcapsules with a dual-function of on-demand drug delivery and cell stimulation for electrical therapy

“…An in vitro study showed that the PDA-MCs enhanced the proliferation and osteogenic differentiation of BMSCs. 23 In the present study, BMSCs have higher levels of cell activity in the PDA-PPy-MCs group than in other groups ( Figure 6), revealing that a microporous structure is an important factor for improving cell adhesion. In summary, PDA-PPy-MCs have the advantages of both the cell-affinity properties of PDA and the microstructure of the MCs and can therefore effectively modulate cell behaviors through the synergistic effects of the PDA and MCs.…”

“…23 First, azodiisobutyronitrile (0.3 g; Sigma, St Louis, MO, USA), polyvinyl pyrrolidone (3 g; Sigma), styrene (30 g;Sigma), and ethanol (200 g; Sigma) were added into a flask with stirring under a nitrogen atmosphere at 65°C and reacted for 12 h. Second, the suspension was collected and centrifuged at 8000 r.p.m. for 10 min, and the PS-MS were obtained by washing with deionized (DI) water five times.…”

“…A magnified micrograph showed that the SPS-MS were well ordered and that their size was 2 μm (Figure 1d). The surface of the SPS-MS was rough because of the sulfonated modification, which facilitates the polymerization of PDA-PPy on the surface of the SPS-MS. 23 After the ED, there are many nanoparticles (NPs) on the surfaces of SPS-MS because PDA and PPy were first polymerized to NPs and further aggregated to form coatings during the polymerization process (Figures 1e and f). 29,30 PDA-PPy-MCs exhibited a porous structure after the removal of the SPS-MPs template (Figures 1g and h), which is beneficial for a high drug-loading ratio and cell adhesion.…”

“…21,22 Cui et al 19 prepared PDA-MCs using a dimethyldiethoxysilane emulsion template and used PDA-MCs for loading doxorubicin. Wang et al 23 used PS-MS as a template to fabricate PDA-MC layer-by-layer films and then immobilized bone morphogenetic protein-2 on the PDA-MC surfaces. However, PDA-MC is not conductive, which limits its applications in electrical therapy.…”

Surface Treatments and Functional Coatings for Biocompatibility Improvement and Bacterial Adhesion Reduction in Dental Implantology

“…It is the case of Bone morphogenetic protein 2, a well-known bone inducer introduced into microporous architectures mimicking the extracellular matrix [80]. In this study, self-assembling polydopamine (PDA) microcapsules, optimal for growth factor immobilization and release, were coated with polystyrene (PS) microspheres and assembled using positively charged chitosan (CHI) layers.…”