Alginate-Sr/Mg Containing Bioactive Glass Scaffolds: The Characterization of a New 3D Composite for Bone Tissue Engineering.

In bone regeneration, combining natural polymer-based scaffolds with Bioactive Glasses (BGs) is an attractive strategy to improve the mechanical properties of the structure, as well as its bioactivity and regenerative potential. Methods: For this purpose, a well-studied alginate/hydroxyapatite (Alg/HAp) porous scaffold was enhanced with an experimental bioglass (BGMS10), characterized by a high crystallization temperature and containing therapeutic ions such as strontium and magnesium. This resulted in an improved biological response compared to 45S5 Bioglass, the "gold" standard among BGs.

A Multidisciplinary Evaluation of Three-Dimensional Polycaprolactone Bioactive Glass Scaffolds for Bone Tissue Engineering Purposes.

In the development of bone graft substitutes, a fundamental step is the use of scaffolds with adequate composition and architecture capable of providing support in regenerative processes both on the tissue scale, where adequate resistance to mechanical stress is required, as well as at the cellular level where compliant chemical-physical and mechanical properties can promote cellular activity. In this study, based on a previous optimization study of this group, the potential of a three-dimensional construct based on polycaprolactone (PCL) and a novel biocompatible Mg- and Sr-containing glass named BGMS10 was explored. Fourier-transform infrared spectroscopy and scanning electron microscopy showed the inclusion of BGMS10 in the scaffold structure.

Effect of Thermal Treatments and Ion Substitution on Sintering and Crystallization of Bioactive Glasses: A Review.

Bioactive glasses (BGs) are promising materials for bone regeneration due to their ability to bond with living bone tissue. However, thermal stability and mechanical properties of BGs need improvement for better clinical performance. In this paper, we present an overview of the influence of different ions on the sintering and crystallization of BGs.

Additive Manufacturing of Polymer/Bioactive Glass Scaffolds for Regenerative Medicine: A Review.

Tissue engineering (TE) is a branch of regenerative medicine with enormous potential to regenerate damaged tissues using synthetic grafts such as scaffolds. Polymers and bioactive glasses (BGs) are popular materials for scaffold production because of their tunable properties and ability to interact with the body for effective tissue regeneration. Due to their composition and amorphous structure, BGs possess a significant affinity with the recipient's tissue.

Adhesive Bioinspired Coating for Enhancing Glass-Ceramics Scaffolds Bioactivity.

Bioceramic scaffolds, composed of a biphasic composite containing bioactive glass and hydroxyapatite, were prepared in this work to overcome the intrinsic limits of the two components taken separately (in particular, their specific reactivities and dissolution rates, which should be tunable as a function of the given clinical requirements). To mimic the biological environment and tune the different stages of cellular response, a coating with gelatin and chondroitin sulphate via Layer-by-Layer (LbL) assembly was presented and discussed. The resulting functionalized scaffolds were affected by the coating in terms of microstructure and porosity.

Low-Temperature Sintering of a New Bioactive Glass Enriched with Magnesium Oxide and Strontium Oxide.

The recent research on bioactive glasses (BGs) has mainly moved on two fronts: (1) introducing ions of therapeutic interest in their composition and (2) the development of scaffolds, fibers, coatings and sintered products starting from BGs in powder form. In this case, the main obstacle to overcome is that BGs rapidly crystallize during heat treatments, thus transforming into glass-ceramics with low reactivity, slow ion release and, eventually, poor mechanical properties. Here an innovative bioactive glass (BGMS_LS), capable of responding to the main limitations of commercial BGs, is presented.

Bioactive Glasses in Periodontal Regeneration: Existing Strategies and Future Prospects-A Literature Review.

The present review deals with bioactive glasses (BGs), a class of biomaterials renowned for their osteoinductive and osteoconductive capabilities, and thus widely used in tissue engineering, i.e., for the repair and replacement of damaged or missing bone.

Bioactive Glass Applications: A Literature Review of Human Clinical Trials.

The use of bioactive glasses in dentistry, reconstructive surgery, and in the treatment of infections can be considered broadly beneficial based on the emerging literature about the potential bioactivity and biocompatibility of these materials, particularly with reference to Bioglass 45S5, BonAlive and 19-93B3 bioactive glasses. Several investigations have been performed (i) to obtain bioactive glasses in different forms, such as bulk materials, powders, composites, and porous scaffolds and (ii) to investigate their possible applications in the biomedical field. Although in vivo studies in animals provide us with an initial insight into the biological performance of these systems and represent an unavoidable phase to be performed before clinical trials, only clinical studies can demonstrate the behavior of these materials in the complex physiological human environment.

Composite Scaffolds for Bone Tissue Regeneration Based on PCL and Mg-Containing Bioactive Glasses.

Polycaprolactone (PCL) is widely used in additive manufacturing for the construction of scaffolds for tissue engineering because of its good bioresorbability, biocompatibility, and processability. Nevertheless, its use is limited by its inadequate mechanical support, slow degradation rate and the lack of bioactivity and ability to induce cell adhesion and, thus, bone tissue regeneration. In this study, we fabricated 3D PCL scaffolds reinforced with a novel Mg-doped bioactive glass (Mg-BG) characterized by good mechanical properties and biological reactivity.

A Review of Bioactive Glass/Natural Polymer Composites: State of the Art.

Collagen, gelatin, silk fibroin, hyaluronic acid, chitosan, alginate, and cellulose are biocompatible and non-cytotoxic, being attractive natural polymers for medical devices for both soft and hard tissues. However, such natural polymers have low bioactivity and poor mechanical properties, which limit their applications. To tackle these drawbacks, collagen, gelatin, silk fibroin, hyaluronic acid, chitosan, alginate, and cellulose can be combined with bioactive glass (BG) nanoparticles and microparticles to produce composites.

A Novel Bioactive Glass Containing Therapeutic Ions with Enhanced Biocompatibility.

A novel bioactive glass containing therapeutic ions with enhanced biocompatibility was designed and produced by the classical melt-quenching route. Starting from a very promising composition (Bio_MS), which combined bioactivity and high crystallization temperature, the ratio between some oxides was tailored to obtain a new and more reactive (in terms of dissolution rate) bioactive glass, called BGMSN (composition in mol%: 6.1 NaO, 31.

Effects of a Novel Bioactive Glass Composition on Biological Properties of Human Dental Pulp Stem Cells.

Functional reconstruction of bone defects represents a clinical challenge in the regenerative medicine field, which targets tissue repair following traumatic injuries and disease-related bone deficiencies. In this regard, the optimal biomaterial should be safe, biocompatible and tailored in order to promote the activation of host progenitor cells towards bone repair. Bioactive glasses might be suitable biomaterials due to their composition being able to induce the host healing response and, eventually, anti-bacterial properties.

Chitosan-Based Bioactive Glass Gauze: Microstructural Properties, In Vitro Bioactivity, and Biological Tests.

Passive commercial gauzes were turned into interactive wound dressings by impregnating them with a chitosan suspension. To further improve healing, and cell adhesion and proliferation, chitosan/bioactive glass wound dressings were produced with the addition of (i) 45S5, (ii) a Sr- and Mg-containing bioactive glass, and (iii) a Zn-containing bioactive glass to the chitosan suspension. SEM and FTIR analyses evidenced positive results in terms of incorporation of bioactive glass particles.

On the in Vitro Biocompatibility Testing of Bioactive Glasses.

In this work, a new 3D cellular model-based on human bone marrow mesenchymal stem cells (BM-MSCs)-was used for the first time to test the 45S5 Bioglass (45S5). Such a model, previously used to evaluate the biologic performance of two novel bioactive glasses, suggested out the regenerative potential of such materials. In fact, BM-MSCs were able both to adhere and colonize the biomaterials, as well as differentiate toward osteoblasts-even in absence of specific growth factors.

A new bioactive glass with extremely high crystallization temperature and outstanding biological performance.

In this work, a new bioactive glass was designed, prepared by means of a melt-quenching route and characterized in terms of both thermal properties and biological performance. The main objective was to obtain a novel product with high temperature of crystallization in view of possible thermal treatments, as well as remarkable biological responsiveness. Thermal behavior was investigated by heating microscopy, differential thermal analysis (DTA) and sintering tests.

In vitro studies of solution precursor plasma-sprayed copper-doped hydroxyapatite coatings with increasing copper content.

In this present study, in vitro characterization on bioactivity and biocompatibility of the copper-doped hydroxyapatite (Cu-HA) coatings deposited onto Ti6Al4V alloy with increasing copper content obtained using solution precursor plasma spray process were evaluated under simulated body fluid (SBF) and cytotoxicity tests. The growth of flake-like structures was observed at the coatings' surface after 7 days of immersion in SBF. Elemental composition analysis showed a calcium-deficient carbonate-containing apatite for the grown layer.

Advanced Open-Celled Structures from Low-Temperature Sintering of a Crystallization-Resistant Bioactive Glass.

Most materials for bone tissue engineering are in form of highly porous open-celled components (porosity >70%) developed by means of an adequate coupling of formulations and manufacturing technologies. This paper is dedicated to porous components from BGMS10 bioactive glass, originally designed to undergo viscous flow sintering without crystallization, which is generally known to degrade the bioactivity of 45S5 bioglass. The adopted manufacturing technologies were specifically conceived to avoid any contamination and give excellent control on the microstructures by simple operations.

Human Mesenchymal Stem Cell Combined with a New Strontium-Enriched Bioactive Glass: An Model for Bone Regeneration.

A 3D cellular model that mimics the potential clinical application of a biomaterial is here applied for the first time to a bioactive glass, in order to assess its biological potential. A recently developed bioactive glass (BGMS10), whose composition contained strontium and magnesium, was produced in the form of granules and fully investigated in terms of biocompatibility in vitro. Apart from standard biological characterization (Simulated Body Fluid (SBF) testing and biocompatibility as per ISO10993), human bone marrow mesenchymal stromal/stem cells (BM-MSCs) were used to investigate the performance of the bioactive glass granules in an innovative 3D cellular model.

Zinc containing bioactive glasses with ultra-high crystallization temperature, good biological performance and antibacterial effects.

Novel bioactive glasses with different amount of zinc oxide (ZnO), namely 2, 3.8 and 5 mol%, were designed, produced by a melt-quenching route and investigated in terms of biological performance. Proper amounts of ZnO were added to a previously developed bioactive glass containing strontium and magnesium, characterized by an ultra-high crystallization temperature.

Bioactive glasses and glass-ceramics versus hydroxyapatite: Comparison of angiogenic potential and biological responsiveness.

Different bioactive glasses (BGs), bioceramics, and their composites were extensively analyzed in terms of biological responsiveness and angiogenic potential. In particular several inorganic materials were considered, namely the widely used 45S5 BG, an experimental BG with low tendency to crystallize, other three experimental BGs doped with strontium and/or magnesium, a commercial hydroxyapatite (HA), and two BG-HA composites (with varying percentages of BG and HA). All these materials were ad hoc prepared and in vitro tested by means of an extensive biological analysis, such as MC3T3-E1 cell viability and proliferation by direct contact assay, alkaline phosphatase activity, mineralized matrix deposition analysis by alizarin red staining, as well as evaluation of angiogenic potential and vascular endothelial growth factor release using ST2 cells.

A New Bioactive Glass/Collagen Hybrid Composite for Applications in Dentistry.

Bioactive glasses (BGs) are currently employed in a wide range of medical and dentistry applications by virtue of their bone-bonding ability. The incorporation of BGs into a collagen matrix may be used to combine the regenerative potential of these materials with the specific biological advantages of collagen. However, most of the collagen/BG composites reported in the literature are scaffolds and there is a lack of moldable putties or injectable systems.

Design of a novel procedure for the optimization of the mechanical performances of 3D printed scaffolds for bone tissue engineering combining CAD, Taguchi method and FEA.

In order to increase manufacturing and experimental efficiency, a certain degree of control over design performances before realization phase is recommended. In this context, this paper presents an integrated procedure to design 3D scaffolds for bone tissue engineering. The procedure required a combination of Computer Aided Design (CAD), Finite Element Analysis (FEA), and Design methodologies Of Experiments (DOE), firstly to understand the influence of the design parameters, and then to control them.

SBF assays, direct and indirect cell culture tests to evaluate the biological performance of bioglasses and bioglass-based composites: Three paradigmatic cases.

A novel bioglass composition (BGMS10), containing strontium and magnesium and characterized by an ultra-high crystallization temperature, is here employed for the first time to produce different composites with the addition of specific amounts of hydroxyapatite. After an investigation of the samples' bioactivity in vitro in a simulated body fluid solution (SBF) - according to a widely used protocol -, the biocompatibility of the new materials was tested with respect to murine fibroblasts both by direct and indirect tests, in order to evaluate possible cytotoxic effects of the materials' eluates. Although none of the samples were cytotoxic and their bioactivity in SBF increased with the increasing amount of the glass in the composite, thus showing the best performance in the case of pure BGMS10 glass, the findings of the biological investigation did not confirm those arising from the SBF assay.

Bone Regeneration by Novel Bioactive Glasses Containing Strontium and/or Magnesium: A Preliminary In-Vivo Study.

In this work, a set of novel bioactive glasses have been tested in vivo in an animal model. The new compositions, characterized by an exceptional thermal stability and high in vitro bioactivity, contain strontium and/or magnesium, whose biological benefits are well documented in the literature. To simulate a long-term implant and to study the effect of the complete dissolution of glasses, samples were implanted in the mid-shaft of rabbits' femur and analyzed 60 days after the surgery; such samples were in undersized powder form.

A comparative in vivo evaluation of bioactive glasses and bioactive glass-based composites for bone tissue repair.

In this work a set of novel materials for bone tissue regeneration have been tested in vivo in an animal model. In fact, despite many studies have been devoted to amorphous 45S5 Bioglass®, there is lack in the literature of works aimed to study the in vivo performance of heat-treated - and thus partially crystallized - 45S5. As widely reported, crystallization limits the bioactivity of 45S5 and is the main reason that prevents a broader use of this material.