Three-dimensional mineralization of dense nanofibrillar collagen-bioglass hybrid scaffolds.
ABSTRACT Scaffolds for bone tissue engineering must meet a number of requirements such as biocompatibility, osteoconductivity, osteoinductivity, biodegradability, and appropriate biomechanical properties. A combination of type I collagen and 45S5 Bioglass may meet these requirements, however, little has been demonstrated on the effect of Bioglass on the potential of the collagen nanofibrillar three-dimensional mineralization and its influence on the structural and mechanical properties of the scaffolds. In this work, rapidly fabricated dense collagen-Bioglass hybrid scaffolds were assessed for their potential for immediate implantation. Hybrid scaffolds were conditioned, in vitro, in simulated body fluid (SBF) for up to 14 days and assessed in terms of changes in structural, chemical, and mechanical properties. MicroCT and SEM analyses showed a homogeneous distribution of Bioglass particles in the as-made hybrids. Mineralization was detected at day 1 in SBF, while ATR-FTIR microscopy and XRD revealed the presence of hydroxyl-carbonated apatite on the surface and within the two hybrid scaffolds at days 7 and 14. FTIR and SEM confirmed that the triple helical structure and typical banding pattern of fibrillar collagen was maintained as a function of time in SBF. Principal component analysis executed on ATR-FTIR microscopy revealed that the mineralization extent was a function of both Bioglass content and conditioning time in SBF. Tensile mechanical analysis showed an increase in the elastic modulus and a corresponding decrease in strain at ultimate tensile strength (UTS) as imparted by mineralization of scaffolds as a function of time in SBF and Bioglass content. Change in UTS was affected by Bioglass content. These results suggested the achievement of a hybrid matrix potentially suitable for bone tissue engineering.
- Handbook of Functional Nanomaterials, Edited by Mahmood Aliofkhazraei, 01/2013: chapter Nanocomposites for Biomedical and Dental Applications.: pages Chapter 9, Volume 4; Nova Publishers., ISBN: 978-1-62948-232-3
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ABSTRACT: Collagen is increasingly attracting attention for bone tissue engineering applications. However, due to its low mechanical properties, applications including mechanical loads or requiring structural integrity are lim-ited. To tackle this handicap, collagen can be combined with (nanoscale) silica in a variety of composite materials that are attractive for bone tissue engineering. Consider-ing research carried out in the past 15 years, this article reviews the literature discussing the development of sil-ica/collagen composites that have been synthesized by adding silica from different sources as inorganic bioactive material to collagen as organic matrix. Different routes for the fabrication of collagen/silica composites are pre-sented, focusing on nanocomposites. In vitro cell bioac-tivity studies demonstrated the osteogenic and, in some cases, angiogenic potential of the composites. Relevant in vivo studies discussing integration of the materials in bone tissue are discussed. Due to the understanding of possible interaction between silicon species and collagen, the effect of different silica precursors on the collagen self-assembly process is also discussed. On the basis of lit-erature results and as discussed in this review, collagen/ silica nanocomposites and hybrids represent attractive biomaterials for bone regeneration applications.01/2013; 2(4):427-447.
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ABSTRACT: To evaluate the antibacterial efficacy of silicate bioactive glass nanoparticles/ collagen composites functionalized with tetracycline hydrochloride (TCH). Different concentrations of tetracycline hydrochloride (TCH) were incorporated on silicate bioactive glass nanoparticles/ collagen composites by dipping these biomaterials for 48 h at 37°C in a solution of simulated body fluid (SBF) plus 0.05, 0.20 or 0.35 mg mL(-1) of the antibiotic. TCH release was assessed in double-distilled water at 37°C up to 72 h. The antibacterial activity of the samples has been evaluated in two ways: inhibition zone test and plate count method. The experiments were performed in vitro up to 48 h on four staphylococci strains (Staphylococcus aureus ATCC29213, ATCC25923, ATCC6538P and Staphylococcus epidermidis ATCC12228. The new composites were also tested for cytotoxicity on MG-63 human osteosarcoma cells. The results showed that the incorporation and release of TCH was dependent on the initial concentration of TCH in SBF. The biomaterials also inhibited the S. aureus cell growth even though the efficacy was similar for all concentration. On the other hand, no cytotoxic effects were found on osteoblast like cells, even at the highest concentration. Considering all results, it can be concluded that the new composite acts as a suitable bioactive carrier of TCH and could have potential in the prevention of biomaterial related infections. The results suggest a potential application as wound dressing. This article is protected by copyright. All rights reserved.Journal of Applied Microbiology 02/2014; · 2.20 Impact Factor