Alkali-free bioactive glasses for bone tissue engineering: A preliminary investigation

Processing of Concentrated Aqueous Zirconia-Bioglass Slips by Slip Casting

“…4) and consequently a lower Ca 2+ and PO 4 3-ions concentration in aqueous solution. According to Goel et al [23], at pH < 9.0 calcium phosphate precipitation does not occur after water immersion due to the low amounts of Ca 2+ and PO 4 3-ions released, therefore in this study a Ca-P layer on the 64S powder surface is not expected. Figure 5 shows the zeta potential versus pH curves of the different powders.…”

The key Features expected from a Perfect Bioactive Glass –How Far we still are from an Ideal Composition?

“…P 2 O 5 ) combined in different proportions. Figure 2 shows most of the investigated compositions in this ternary system, as well as in the binary DiFA and DiTCP ones [25][26][27][28][29].…”

“…In a third sub-series of compositions, these partial oxide substitutions were combined in an equimolar basis [32,33]. The effects of such individual or combined substitutions on the relevant properties of the resulting bioactive glasses were investigated and reported in several publications [30][31][32][33].These alkali-free bioactive glasses revealed to have several distinctive features including: moderate degradation rate, accompanied by a fast bio mineralisation rate in vitro with the formation of a hydroxycarbonate apatite (HCA) surface layer after 1 h of immersion in simulated body fluid (SBF) [26,30,32]; the ability to reduce oxidative stress [30,32]; osteogenic activity, inducing the differentiation of hMSCs into bone forming cells even in the absence of osteogenic medium [29]. This osteo induction effect was significantly greater in comparison to that of 45S5 Bioglass® [34]; and excellent bone bonding ability confirmed by in vivo studies using sheep as animal model [35].…”

“…The pH values of the suspensions are lower in comparison to those of 45S5 Bioglass® and the particle size of powder frits can be more conveniently reduced and expose a larger surface area to the dispersion liquid without undergoing a so extensive dissolution [37,38]. Still more important from the overall processing point of view is the excellent sintering ability, achieving full densification before the onset of crystallization, resulting in strong mechanical properties [25][26][27][28][31][32][33]. Figure 4 compares porous scaffolds fabricated by robo casting, an extrusion based additive manufacturing technique that enables designing not only the external form and dimensions, but also tailoring the internal structure.…”

Aspekty nanomateriałów w zastosowaniach cywilnych i militarnych. Część 2. Wykorzystanie i obawy wynikające z ich uwalniania do środowiska przyrodniczego

“…h) Zastosowania medyczne, w których udział nanomateriałów szacuje się na 2%, i podlega on szybkiemu wzrostowi obejmują: -bioaktywne szkła, wykazujące właściwości antybakteryjne, które zastępują tradycyjne wypełnienia, uczestniczą w procesach metabolicznych i wiążą się trwale z tkankami; jak np. borokrzemian wapniowoglinowy, krzemian-fosforanowy sodowo-wapniowy [118,119]; -piezoelektryczny materiał, tlenek binarny (PZT) [PbZr(x)Ti(1-x)]O3 generujący energię elektryczną w wyniku naprężeń mechanicznych generowanych wewnątrz organizmu stosowany, jako zasilacz rozruszników serca (ang. peace-makers) [120]; -kompozyty typu szkło-materiał ceramiczny stosowany w leczeniu ubytków kostnych; kręgosłupa, kości biodrowej raz stawu kolanowego [121]; -rozmaite preparaty stosowane w chemioterapii, które przyłączone do określonego biopolimeru (np.…”