Synthesis and characterization of antibacterial drug loaded β-tricalcium phosphate powders for bone engineering applications

Fiber-Templated 3D Calcium-Phosphate Scaffolds for Biomedical Applications: The Role of the Thermal Treatment Ambient on Physico-Chemical Properties

“…Specifically, it was noticed that the band positions, shapes, and amplitudes of all air heat-treated samples ( Figure 3 a,b) closely mirrored the spectral envelope obtained in the case of the pure β-TCP commercial powder ( Figure 4 ). All the orthophosphate characteristic vibrational bands of a β-TCP compound were featured, i.e., ν 4 asymmetric bending (~550 and 600–601 cm −1 ), ν 1 symmetric stretching (~943 cm −1 ), and the ν 3 triply degenerated asymmetric stretching (~968–970, 1003, 1014–1016, 1040–1041, 1082, and 1118 cm −1 ) [ 16 , 63 ]. In the case of the air sintered specimens only, the characteristic IR bands of β-TCP were evidenced ( Figure 3 a,b), thus, confirming the XRD phase identification ( Figure 1 a,b).…”

“…The decomposition of β-TCP phase into the α-TCP and the supplemental presence of α-Ca 2 P 2 O 7 ( Figure 3 c,d), recorded in the case of nitrogen thermally-treated samples (with the exception of the compact 0.00 wt.% Gr one), was exposed as well by occurrence of two concomitant events: (i) the β-TCP bands became less conspicuous (as result of the juxtaposition of the IR absorption maxima of both β-TCP and α-TCP, leading to convoluted bands, as evidenced by both our experiments in the case of the β-TCP + α-TCP blend ( Figure 4 ) and Carrodegues et al [ 63 ] and (ii) the emergence of well-defining protruding bands characteristic to the vibrational modes of a pyrophosphate phase ( Figure 4 ): asymmetric bending (~575 cm −1 ), symmetric stretching of P–O bridges (~757 cm −1 ), asymmetric stretching of P–O bridges (~981 cm −1 ), symmetric stretching mode of terminal P–O (~1020 cm −1 ), or asymmetric stretching mode of terminal P–O (~1057–1058 cm −1 and ~1157 cm −1 ) [ 16 , 59 ], superimposed over the dominant TCP spectral envelope.…”

“…The well-known drawbacks of the standard biological approaches (e.g., autografts and allografts) [ 4 , 8 , 9 , 10 , 11 ] have put a concerted focus on alternative solutions based on calcium phosphates (CaP)-based products (i.e., HA, β- and α-tricalcium phosphate (TCP, Ca 3 (PO 4 ) 2 ), brushite (DCPD, CaHPO 4 ·2H 2 O), calcium pyrophosphate (CPP, Ca 2 P 2 O 7 ), or the combination of them) [ 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. The extension of the range of biomedical applicability requires continuous improvements of this category of bioactive materials.…”

“…Another widely-discussed requirement is the dissolution and resorption degree of the bone graft substitute materials [ 5 , 13 , 21 ] and the favorable hydroxyapatite formation [ 22 , 23 , 24 ]. Therefore, HA with/without β-TCP/α-TCP is usually destined for the fabrication of 3D compact and porous structures, while DCPD can be used alone or in combination with any other calcium phosphate for the preparation of bone cements and bone fillers [ 13 , 16 , 25 , 26 ]. Products fabricated predominantly of β-TCP and α-TCP are rarely suggested for load-bearing applications owing to their low resistance and high resorption rates and, thus, insufficient time for a proper bonding with the surrounding bone tissue [ 13 , 19 , 27 ].…”

“…However, the addition of different ratios of TCP materials was proposed for a controlled degradation rate and an improved protein adsorption on the implant surface [ 5 , 28 , 29 ]. Supplementary CPPs were also found promising for the development of bone grafting [ 16 , 17 , 30 ].…”