Hybrid Core-Shell Polymer Scaffold for Bone Tissue Regeneration

Abstract

A great promise for tissue engineering is represented by scaffolds that host stem cells during proliferation and differentiation and simultaneously replace damaged tissue while maintaining the main vital functions. In this paper, a novel process was adopted to develop composite scaffolds with a core-shell structure for bone tissue regeneration, in which the core has the main function of temporary mechanical support, and the shell enhances biocompatibility and provides bioactive properties. An interconnected porous core was safely obtained, avoiding solvents or other chemical issues, by blending poly(lactic acid), poly(ε-caprolactone) and leachable superabsorbent polymer particles. After particle leaching in water, the core was grafted with a gelatin/chitosan hydrogel shell to create a cell-friendly bioactive environment within its pores. The physicochemical, morphological, and mechanical characterization of the hybrid structure and of its component materials was carried out by means of infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and mechanical testing under different loading conditions. These hybrid polymer devices were found to closely mimic both the morphology and the stiffness of bones. In addition, in vitro studies showed that the core-shell scaffolds are efficiently seeded by human mesenchymal stromal cells, which remain viable, proliferate, and are capable of differentiating towards the osteogenic phenotype if adequately stimulated.

Hydrogel-chitosan and polylactic acid-polycaprolactone bioengineered scaffolds for reconstruction of mandibular defects: a preclinical in vivo study with assessment of translationally relevant aspects

“…After particle leaching in water, the resulting porous core was grafted with HyCh to create a bioactive shell within its pores. The nal amount of grafted HyCh was 3% by weight [32,34]. Figure 2 shows the morphological analysis of cryogenically obtained cross sections for HyCh and PLA-PCL-HyCh scaffolds.…”

“…The hybrid scaffolds, herein acronymized as PLA-PCL-HyCh, resulted in an exceptional improvement of mechanical properties compared to the pure hydrogel, closely mimicking both the stiffness and the morphology of bones. Furthermore, hybrid PLA-PCL-HyCh scaffolds showed excellent capability in supporting cell growth, osteogenic differentiation, and mineralization of bone marrow hMSCs (BM-hMSCs), demonstrating their potential application for bone regeneration [28][29][30][31][32][33][34].…”

“…A pilot translational study assessing bone regeneration sustained by HyCh and PLA-PCL-HyCh polymer scaffolds in an in vivo animal model is presented herein. The study was aimed at: 1) evaluating the in vivo bone regenerative potential of materials developed by our research group (i.e., HyCH and PLA-PCL-HyCh) [28,32,34]:…”

Proliferation kinetics and mineralization properties of MC3T3‐E1 cells on whey protein isolate scaffolds for bone tissue regeneration

“…It acts as a geometrical template, or blueprint, for the growing tissue. [ 3,4 ] Concurrently, osteoinductive scaffolds are able to recruit cells into the bone‐deficient site from surrounding tissue and promote proliferation to achieve a fully populated scaffold while also inducing differentiation into osteoblasts, which begin to lay down the extracellular matrix and mineral deposits that comprise immature bone tissue. [ 5–8 ]…”

“…In the specific case of bone tissue, the method for the growing tissue. [3,4] Concurrently, osteoinductive scaffolds are able to recruit cells into the bone-deficient site from surrounding tissue and promote proliferation to achieve a fully populated scaffold while also inducing differentiation into osteoblasts, which begin to lay down the extracellular matrix and mineral deposits that comprise immature bone tissue. [5][6][7][8] Bone tissue continues to be formed and remodeled on a time scale comparable to that of the degradation rate of the scaffold.…”