Microstructural characterization and in vitro bioactivity of porous glass-ceramic scaffolds for bone regeneration by synchrotron radiation X-ray microtomography

Abstract

One of the key purposes of bone tissue engineering is the development of new biomaterials that can stimulate the body's own regenerative mechanism for patient's anatomical and functional recovery. Bioactive glasses, due to their versatile properties, are excellent candidates to fabricate porous 3-D architectures for bone replacement. In this work, morphological and structural investigations are carried out on Bioglass®- and CEL2-derived scaffolds produced by sponge replication (CEL2 is an experimental glass developed at Politecnico di Torino). Synchrotron radiation X-ray microtomography is used to study the samples 3-D architecture, pores size, shape, distribution and interconnectivity, as well as the growth kinetics on scaffolds struts of a newly formed apatitic phase during in vitro treatment in simulated body fluid, in order to describe from a quantitative viewpoint the bioactive potential of the analyzed biomaterials. An accurate comparison between architectural features and bioactive behaviour of Bioglass®- and CEL2-derived scaffolds is presented and discussed

Feasibility of glass–ceramic coatings on alumina prosthetic implants by airbrush spraying method

“…Micro-CT is an advanced characterization technique that, when combined with 3-D image analysis, can provide both qualitative and quantitative information on biomaterials; in recent years, it has been often employed for the non-destructive investigation of porous structures of biomedical interest, such as cancellous bone and tissue engineered scaffolds [31][32][33]. In the present work, micro-CT was interestingly used to assess whether a continuous SCNA coating was actually deposited on the whole curved surface of the alumina substrate by airbrush spraying; this investigation, performed in a 3-D space, is complementary to SEM analyses that provide information on a single 2-D cross-section of the sample.…”

Quantifying the micro-architectural similarity of bioceramic scaffolds to bone

“…The choice of using this experimental material rather than the well-known 45S5 Bioglass®, which is considered as a standard reference for biomedical glasses, is based on previous results on this new glass and related glass-ceramic derivatives. CEL2-based foams were reported to exhibit higher compressive strength compared to 45S5 Bioglass®-derived scaffolds with analogous 3D architecture and porosity; this was due to the higher sinterability of Ceramics International xxx (xxxx) xxx-xxx CEL2, which allows producing well-densified and strong struts [33]. Another advantage of CEL2 compared to 45S5 Bioglass® concerns the superior in vitro bioactivity, as formation of an hydroxyapatite-like layer was observed to occur more rapidly on CEL2 scaffolds [36].…”

“…However, scaffold and bone micro-architectures are generally compared only in qualitative, often fairly subjective, fashion. High-resolution X-ray micro-computed tomography (micro-CT) permits researchers to characterize porous scaffolds and bone accurately and non-destructively [32,33] and to estimate the microarchitectural parameters that may be used to develop quantitative criteria for their comparison [29,34].…”

Novel full-ceramic monoblock acetabular cup with a bioactive trabecular coating: design, fabrication and characterization

“…Periodic replacement of SBF is a common experimental practice to simulate fluid circulation in the human body [39][40][41][42] as the cation concentration in the solution progressively decreases during the experiment as a result of changes in the sample surface chemistry. The pH of the solution was monitored daily.…”