Piezoelectric 3-D Fibrous Poly(3-hydroxybutyrate)-Based Scaffolds Ultrasound-Mineralized with Calcium Carbonate for Bone Tissue Engineering: Inorganic Phase Formation, Osteoblast Cell Adhesion, and Proliferation

Abstract

Elaboration of novel biocomposites providing simultaneously both biodegradability and stimulated bone tissue repair is essential for regenerative medicine. In particular, piezoelectric biocomposites are attractive because of a possibility to electrically stimulate cell response. In the present study, novel CaCO 3 -mineralized piezoelectric biodegradable scaffolds based on two polymers, poly[(R)3hydroxybutyrate] (PHB) and poly[3-hydroxybutyrate-co-3hydroxyvalerate] (PHBV), are presented. Mineralization of the scaffold surface is carried out by the in situ synthesis of CaCO 3 in the vaterite and calcite polymorphs using ultrasound (U/S). Comparative characterization of PHB and PHBV scaffolds demonstrated an impact of the porosity and surface charge on the mineralization in a dynamic mechanical system, as no essential distinction was observed in wettability, structure, and surface chemical compositions. A significantly higher (4.3 times) piezoelectric charge and a higher porosity (∼15%) lead to a more homogenous CaCO 3 growth in 3-D fibrous structures and result in a two times higher relative mass increase for PHB scaffolds compared to that for PHBV. This also increases the local ion concentration incurred upon mineralization under U/S-generated dynamic mechanical conditions. The modification of the wettability for PHB and PHBV scaffolds from hydrophobic (nonmineralized fibers) to superhydrophilic (mineralized fibers) led to a pronounced apatite-forming behavior of scaffolds in a simulated body fluid. In turn, this results in the formation of a dense monolayer of well-distributed and proliferated osteoblast cells along the fibers. CaCO 3 -mineralized PHBV surfaces had a higher osteoblast cell adhesion and proliferation assigned to a higher amount of CaCO 3 on the surface compared to that on PHB scaffolds, as incurred from micro-computed tomography (μCT). Importantly, a cell viability study confirmed biocompatibility of all the scaffolds. Thus, hybrid biocomposites based on the piezoelectric PHB polymers represent an effective scaffold platform functionalized by an inorganic phase and stimulating the growth of the bone tissue.

Colloids-at-surfaces: Physicochemical approaches for facilitating cell adhesion on hybrid hydrogels

“…The additional coating increases the hydrophilicity, which significantly improves cell adhesion. [107] (Fig. 8).…”

Polymer- and Hybrid-Based Biomaterials for Interstitial, Connective, Vascular, Nerve, Visceral and Musculoskeletal Tissue Engineering

“…Collagen-chitosan based PDMS Improving cell adhesion [255] Collagen-I based Polyacrylamide Improving cell adhesion [256,257] Laminin and RGD based PEG Improving cells adhesion [258,259] RGD based Alginate Improving cells adhesion [75] Fibrin based PLG Anastomosis with the host vasculature and angiogenesis [209] Agrin or laminin based Alginate Exhibited acetylcholine receptor (AChR) clustering [210,211] Cartilage (Section 7.3) Hyaluronic acid based PLGA Improving cell migration and proliferation [45] Platelet-rich-plasma based PGA Homogeneous hyaline-like cartilage tissue repair. [260] Fibrinogen based PEG Improving cells adhesion [261] Fibrin based PGA Bio-sustainability of cell-based tissue regeneration (without in vitro cultivation) [262,263] Hyaluronic acid based Alginate Improving cell migration and proliferation [263,264] Tri-(calcium phosphate) based PLGA Improving osteochondral composition [263,265] Bones (Section 7.4) CaCO 3 /PHB & PHBV based PHB and PHBV Improving cells adhesion and ossification [266] CaCO 3 with loaded ALP Alginate Improving cells adhesion and ossification [228]…”

Recent Advances in the Use of Polyhydroyalkanoates in Biomedicine

“…The osteoinductivity and osteoconductivity of the bioactive scaffolds were attained mainly due to the incorporation of HA. By combining CaCO 3 -mineralized piezoelectric with PHB- and PHBV-based scaffolds, Chernozem et al [37] elaborated PHA biocomposites that provided biodegradability and stimulated bone tissue repair. The presence of mineral led to a pronounced apatite-forming behavior of the biodegradable PHAs scaffolds, and this turned out to stimulate the growth of the bone tissue.…”