PHBV/PLLA-based composite scaffolds fabricated using an emulsion freezing/freeze-drying technique for bone tissue engineering: surface modification and in vitro biological evaluation

Abstract

Tissue engineering combines living cells with biodegradable materials and/or bioactive components. Composite scaffolds containing biodegradable polymers and nanosized osteoconductive bioceramic with suitable properties are promising for bone tissue regeneration. In this paper, based on blending two biodegradable and biocompatible polymers, namely poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(L-lactic acid) (PLLA) with incorporated nano hydroxyapatite (HA), three-dimensional composite scaffolds with controlled microstructures and an interconnected porous structure, together with high porosity, were fabricated using an emulsion freezing/freeze-drying technique. The influence of various parameters involved in the emulsion freezing/freeze-drying technique was studied for the fabrication of good-quality polymer scaffolds based on PHBV polymers. The morphology, mechanical properties and crystallinity of PHBV/PLLA and HA in PHBV/PLLA composite scaffolds and PHBV polymer scaffolds were studied. The scaffolds were coated with collagen in order to improve wettability. During in vitro biological evaluation study, it was observed that SaOS-2 cells had high attachment on collagen-coated scaffolds. Significant improvement in cell proliferation and alkaline phosphatase activity for HA-incorporated composite scaffolds was observed due to the incorporation of HA. After 3 and 7 days of culture on all scaffolds, SaOS-2 cells also had normal morphology and growth. These results indicated that PHBV/PLLA-based scaffolds fabricated via an emulsion freezing/freeze-drying technique were favorable sites for osteoblastic cells and are promising for the applications of bone tissue engineering.

A Non-woven Path: Electrospun Poly(lactic acid) Scaffolds for Kidney Tissue Engineering

“…4. Although, our results regarding fibre diameter and its influence on cell behaviour are not conclusive, it has been shown to have major implication in previous studies [39,[56][57][58]. There is some disparity between our data for CellTitre blue and DNA quantification, this is possibly as a result of the much greater porosity gained from cryogenic electrospinning where unattached cells become trapped within the scaffold.…”

Surface characterization and osteoblast-like Cells culture on collagen modified PLDLA scaffolds

“…Although the adhesion of osteoblasts on PLDLA-AAc was significantly lower than on PLDLA-Col scaffolds, the cell proliferation and morphology were similar on scaffolds polymerized with acrylic acid. This finding probably reflects the fact that the grafting of a hydrophilic (-COOH) group onto a polymeric surface promotes the adsorption of proteins from the culture medium and that this, in turn, stimulates several biological signaling pathways 39,40 . Another point to be considered for the suitable cell proliferation and morphology found on PLDLA-AAc and PLDLA-Col scaffolds is the topographic features obtained on the materials surface after treatment.…”

Comparison of Cell Proliferation and Adhesion of Human Osteoblast Differentiated Cells on Electrospun and Freeze-Dried PLGA/Bioglass Scaffolds

“…Stem cells may be extracted from different origins, like adipose tissue, bone marrow, muscle, periosteum, and placenta (26)(27)(28)(29). Endometrial stem cells are in fact a group of stem cells (adult stem cell), which are extracted from endometrial tissue of the uterus, which present some features similar to mesenchymal stem cells.…”