Abstract 45S5 bioactive glass ( BG ) scaffolds show great potential in bone tissue engineering due to their superior osteoinductivity and osteoconductivity. However, such scaffolds generally possess poor mechanical properties. Here, inspired by the reinforcing principle of confined concrete elements in civil engineering, poly caprolactone ( PCL )/polyethylene glycol ( PEG ) film‐wrapped 45S5 BG scaffolds were prepared by gluing highly porous foam–replicated BG scaffolds and electrospun PCL / PEG films together with a PCL layer. The results showed that the compressive strength of the PCL / PEG film‐wrapped scaffolds was greatly improved, compared to that of unwrapped BG scaffolds. Moreover, the PCL / PEG film exhibited hydrophilicity, responsible for improved cell activity with respect to the hydrophobic PCL one. Thus, the present work introduces a convenient approach to improve the mechanical properties of highly porous bioceramic scaffolds, and is relevant for future robust scaffold design.
Polyurethane (PUR) and polyurethane/poly(d, l-lactide) acid (PUR/PDLLA) based scaffolds coated with Bioglass® particles for application in bone tissue engineering were fabricated. The slurry-dipping method was used for coating preparation. The homogeneous structure of the Bioglass® coatings on the surface of the PUR and PUR/PDLLA foams indicated a good adhesion of the bioactive glass particles to polyurethane without any additional surface treatment. In vitro studies in simulated body fluid (SBF) were performed to study the influence of Bioglass® coating on biodegrability and bioactivity of PUR-based scaffolds. The surface of Bioglass®-coated samples was covered by a layer of carbonate-containing apatite after 7 days of immersion in SBF, while in uncoated polymer samples apatite crystals were not detected even after 21 days of immersion in SBF. The apatite layer was characterized by scanning electron microscopy (SEM), EDS analysis and attenuated total reflectance–Fourier transform infrared spectrometry (FTIR–ATR). Weight loss measurements showed that the in vitro degradation rate of the composite scaffolds in SBF was higher in comparison to uncoated polyurethane samples. PUR and PUR/PDLLA foams with Bioglass® coating have potential to be used as bioactive, biodegradable scaffolds in bone tissue engineering.
Tissue engineering (TE) is a biomedical field in continuous expansion. However, there are still many challenges, and the further development of TE approaches requires interdisciplinary interaction and collaboration among various research areas with a notable contribution expected from biomaterials science. In the last couple of decades, significant advances in the development of biomaterial-based scaffolds for hard and soft tissue regeneration have been accomplished, including the manufacture of biocomposites that combine natural or synthetic polymers with bioactive glasses or glass-ceramics. These novel biomaterials present the possibility of tailoring a variety of parameters and properties such as degradation kinetics, mechanical properties, and chemical composition according to the aimed application. This chapter presents a concise update of the field of biopolymer–bioactive glass composite scaffold development for TE covering several popular processing techniques for biocomposite fabrication, namely, microsphere processing, solvent casting-particulate leaching method, electrospinning, freezedrying, and rapid prototyping techniques, which lead to scaffolds exhibiting a variety of 3Dmorphologies and different pore structures.
The incorporation of bioactive glass into bone tissue-engineered scaffolds can be widely beneficial based on emerging evidence in the literature about the angiogenic potential of this material, particularly 45S5 Bioglass((R)). This article reviews the literature discussing in vitro studies which have demonstrated that increases in angiogenic indicators have been achieved through both direct and indirect contact of relevant cells with 45S5 Bioglass((R)) particles or with their dissolution products. A few available in vivo studies confirming the ability of bioactive glass, incorporated into scaffolds, to stimulate neovascularization are also discussed. Suggestions for further research are given, highlighting the need for specific investigations designed to assess the effect of particular ion dissolution products from bioactive glasses and their relative concentration on angiogenesis both in vitro and in vivo.
Myocardial infarction is one of the major causes of mortality as well as morbidity around the world. Currently available treatment options face a number of drawbacks, hence cardiac tissue engineering, which aims to bioengineer functional cardiac tissue, for application in tissue repair, patient specific drug screening and disease modeling, is being explored as a viable alternative. To achieve this, an appropriate combination of cells, biomimetic scaffolds mimicking the structure and function of the native tissue, and signals, is necessary. Among scaffold fabrication techniques, three-dimensional printing, which is an additive manufacturing technique that enables to translate computer-aided designs into 3D objects, has emerged as a promising technique to develop cardiac patches with a highly defined architecture. As a further step toward the replication of complex tissues, such as cardiac tissue, more recently 3D bioprinting has emerged as a cutting-edge technology to print not only biomaterials, but also multiple cell types simultaneously. In terms of bioinks, biomaterials isolated from natural sources are advantageous, as they can provide exceptional biocompatibility and bioactivity, thus promoting desired cell responses. An ideal biomimetic cardiac patch should incorporate additional functional properties, which can be achieved by means of appropriate functionalization strategies. These are essential to replicate the native tissue, such as the release of biochemical signals, immunomodulatory properties, conductivity, enhanced vascularization and shape memory effects. The aim of the review is to present an overview of the current state of the art regarding the development of biomimetic 3D printed natural biomaterial-based cardiac patches, describing the 3D printing fabrication methods, the natural-biomaterial based bioinks, the functionalization strategies, as well as the in vitro and in vivo applications.
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