Design of novel three-phase PCL/TZ–HA biomaterials for use in bone regeneration applications

Abstract

The design of bioactive scaffold materials able to guide cellular processes involved in new-tissue genesis is key determinant in bone tissue engineering. The aim of this study was the design and characterization of novel multi-phase biomaterials to be processed for the fabrication of 3D porous scaffolds able to provide a temporary biocompatible substrate for mesenchymal stem cells (MSCs) adhesion, proliferation and osteogenic differentiation. The biomaterials were prepared by blending poly(epsilon-caprolactone) (PCL) with thermoplastic zein (TZ), a thermoplastic material obtained by de novo thermoplasticization of zein. Furthermore, to bioactivate the scaffolds, microparticles of osteoconductive hydroxyapatite (HA) were dispersed within the organic phases. Results demonstrated that materials and formulations strongly affected the micro-structural properties and hydrophilicity of the scaffolds and, therefore, had a pivotal role in guiding cell/scaffold interaction. In particular, if compared to neat PCL, PCL-HA composite and PCL/TZ blend, the three-phase PCL/TZ-HA showed improved MSCs adhesion, proliferation and osteogenic differentiation capability, thus demonstrating potential for bone regeneration.

Processing/structure/property relationship of multi‐scaled PCL and PCL–HA composite scaffolds prepared via gas foaming and NaCl reverse templating

“…Usually, the decrease of the ALP activity of MG63 cells is associated to the expression of later-stage osteogenic markers and to the begin of calcium deposition (Yoshida et al, 2010). As shown in Figure 8b, the cells cultured within the PCL and PCL-HA 5 composite scaffolds expressed similar calcium contents after 14 days of culture, suggesting that higher HA amounts are required to enhance the deposited calcium at the early stages of in vitro MG63 culture (Guarino et al, 2008;Kim et al, 2006;Salerno et al, 2010). In agreement with the results of Figure 8, a similar expression of the osteopontin, a phosphoprotein that regulate the formation and remodeling of mineralized tissues, was observed after 14 days for the MG63 cultured within the PCL and PCL-HA 5 scaffolds (Fig.…”

“…There are several factors affecting the osteogenic differentiation of cells in vitro. Parameters such as materials chemistry and topography have been proved to significantly influence the osteogenic expression of different cell phenotypes (Guarino et al, 2008;Karageorgiou and Kaplan, 2005;Lange et al, 2002;Salerno et al, 2010). Similarly, seeding density and spatial distribution have also been indicated as key factors influencing the differentiation and extracellular matrix deposition by osteogenic induced cells in vitro (Lode et al, 2008).…”

Strategies to Produce Thermoplastic Starch–Zein Blends: Effect on Compatibilization

“…7b). As reported by several authors for similar systems [25][26][27], the TGA curves can be divided into three stages: (1) volatilization and degradation of both water and plasticizers; (2) major polymer degradation by weaker bond cleavage; and (3) polymer degradation by stronger bond cleavage. The onset and midpoint temperature of major degradation stage (T do and T dm ) and the percentage weight of the final residue can provide information on the thermal stability of the materials obtained.…”

Macroporous and nanometre scale fibrous PLA and PLA–HA composite scaffolds fabricated by a bio safe strategy

“…In this work, the percentage of interconnected porosity in the different scaffolds was calculated by assessing the volume percent of retained water inside the pores of the samples. 30 The E value decreased further, down to 0.15 MPa, when PLA scaffolds were prepared using 200-400 mm gelatin particles following strategy 3. The design of porous scaffolds with controlled mechanical properties is strongly required to promote cell adhesion and biosynthesis and, concomitantly, to dene suitable in vitro and/ or in vivo applications.…”

“…9 For instance, it was observed that ions formed in the dissolution products of bioactive glasses can stimulate the expression of several genes of osteoblasts. 11 By taking advantage of the formability of polymers and by including a controlled-amount of a bioactive ceramic phase, porous scaffolds with enhanced morphology and proper structural properties can be achieved. 10 Development of porous composite scaffolds is attractive as it takes the advantages of two or more types of materials, which can be combined to suit better the chemical and physical demands of the host tissue.…”