Natural and Synthetic Polymers for Bone Scaffolds Optimization

Abstract

Bone tissue is the structural component of the body, which allows locomotion, protects vital internal organs, and provides the maintenance of mineral homeostasis. Several bone-related pathologies generate critical-size bone defects that our organism is not able to heal spontaneously and require a therapeutic action. Conventional therapies span from pharmacological to interventional methodologies, all of them characterized by several drawbacks. To circumvent these effects, tissue engineering and regenerative medicine are innovative and promising approaches that exploit the capability of bone progenitors, especially mesenchymal stem cells, to differentiate into functional bone cells. So far, several materials have been tested in order to guarantee the specific requirements for bone tissue regeneration, ranging from the material biocompatibility to the ideal 3D bone-like architectural structure. In this review, we analyse the state-of-the-art of the most widespread polymeric scaffold materials and their application in in vitro and in vivo models, in order to evaluate their usability in the field of bone tissue engineering. Here, we will present several adopted strategies in scaffold production, from the different combination of materials, to chemical factor inclusion, embedding of cells, and manufacturing technology improvement.

Innovative Options for Bone Metastasis Treatment: An Extensive Analysis on Biomaterials-Based Strategies for Orthopedic Surgeons

“…The promising results of this work open the possibility to design new medicated scaffolds with both pro-regenerative molecules and antineoplastic agents to better treat BM patients. Another issue related to polyesters, PCL and similar compounds (e.g., polyanhydrides, polyfumarates, polycarbonates, polydioxanone) is related to their poor mechanical properties, so that a main approach is to blend them with inorganic reinforcing phases or fibers, also resulting in the improving of osteobiological properties ( Puppi et al, 2010 ; Yao et al, 2017 ; Donnaloja et al, 2020 …”

“…Such polymers can be obtained both from animal sources (e.g., collagen, chitosan) and plant sources (e.g., alginates, cellulose, silk fibroin); altogether they represent a valid option among biomaterials because of low manufacturing and management costs, ease of supply and renewability, biodegradability, biomimicry and biocompatibility. However, the limits of natural polymers are not negligible and include the following: rejection and immunogenic response, disease transmission, fast degradation rate and poor mechanical properties that preclude their applications as pure constituent in orthopedic implants ( Puppi et al, 2010 ; Bose et al, 2017 ; Donnaloja et al, 2020 ). Since collagen is the major constituent of the organic part of bone, it is particularly interesting and has been used alone or in composites in various forms such as fibers, foams and sponges.…”

“…Since collagen is the major constituent of the organic part of bone, it is particularly interesting and has been used alone or in composites in various forms such as fibers, foams and sponges. It has also been widely used as a bioactive molecule carrier ( Puppi et al, 2010 ; Cunniffe and O’Brien, 2011 ; Ige et al, 2012 ; Gohil et al, 2017 ; Donnaloja et al, 2020 ). Nevertheless, collagen alone does not mimic the complex composition of bone tissue; the unique properties of bone are strictly related to its complex 3D structure and to the chemical interaction of its mineral nuclei with the collagenous matrix.…”

Development of Polymeric Nanocomposite (Xyloglucan-co-Methacrylic Acid/Hydroxyapatite/SiO2) Scaffold for Bone Tissue Engineering Applications—In-Vitro Antibacterial, Cytotoxicity and Cell Culture Evaluation

“…The limitations of auto-grafts because of donor availability issues compelled scientists to develop biocompatible composite materials for bone tissue engineering. We are reporting here polymeric scaffolds, synthesized for the bone tissue applications, because of their anticipated porous, physicochemical, degradability and biomechanical properties with tunable characteristics [5,6]. Typically, tissue-engineering approaches involve porous composite scaffolds for living cells.…”

Acrylate–gelatin–carbonated hydroxyapatite (cHAP) composites for dental bone-tissue applications

“…[8][9][10][11][12] Scaffolds made of synthetic polymers have been studied for bone-tissue engineering applications as they are able to produce materials that exhibit both toughness and plasticity, the most commonly used synthetic polymers are polylactic acid (PLA), polyglycolic acid (PGA), copolymers of PLA and PGA, polycaprolactone, and polymethylmethacrylate (PMMA). [13][14][15][16][17][18][19][20] Due to their different mechanical properties and degradation rates, as well as the absence of osteoconductivity (supporting bone growth and encouraging the ingrowth of surrounding bone), the synergistic combination of calcium phosphate (CaP) as an osteoconductive bioabsorbable ceramic in a polymeric matrix has been explored. [21][22][23] These inorganic-organic hybrids possess an advantage over single components as their interactions at a molecular level can provide interdependent properties while acting as a single-phase material.…”