Antibacterial efficiency of alkali-free bio-glasses incorporating ZnO and/or SrO as therapeutic agents

Dextran-Thyme Magnesium-Doped Hydroxyapatite Composite Antimicrobial Coatings

“…Comparative FTIR-ATR spectra of the (a-c) 10MgHAp (dotted line) and 10MgHAp-Dex-thyme powders (solid line); (d-f) dextran and thyme essential oil raw materials; and (g-i) 10MgHAp-Dex-thyme coating, zoomed over three relevant (a,d,g) fingerprint and (b,c,e,f,h,i) functional groups regions: (a,d,g) 500-1180 cm −1 ; (b,e,h) 1180-1800 cm −1 ; and (c,f,i) 2500-3750 cm −1 . [30,[45][46][47][48] Nowadays, due to the appearance of microorganisms resilient to conventional therapies, studies regarding the antimicrobial effects of various types of possible antimicrobial agents, such as metallic ions (copper, iron, silver, magnesium, zinc), inorganic nanoparticles, or essential oils, are performed in the search for efficient solutions with a wider action range against pathogens [1,2,18,20,22,38,58]. In this paper, we investigated for the first time, the influence of Mg-doped HAp enhanced with thyme essential oil in a dextran matrix, in both solution and coating form, on the development of microbial biofilms of some of the most prevalent fungal and Gram-positive and Gram-negative bacterial strains.…”

“…However, standalone, this material does not possess the ability to inhibit bone resorption and, markedly important, to endow antimicrobial properties. This needs to be emphasized as the bacterial-associated infections are currently a major cause of bone scaffolds and dental implants failure [15][16][17][18]. Consequently, numerous studies have been conducted for the development of a synthetic HAp with enhanced properties that could lead to an improvement of mechanical properties, osteointegration, implantation efficiency, and prevention of post-operatory infections [1,2].…”

The Beneficial Mechanical and Biological Outcomes of Thin Copper-Gallium Doped Silica-Rich Bio-Active Glass Implant-Type Coatings

“…The FTIR spectra of the simple and Cu & Ga substituted SBG source biomaterials, and of the RF-MS derived coatings are presented together in Figure 4a-c. Both the FastOs ® BG-based source materials (Figure 4a) were characterized by the presence of large IR absorption bands with four maxima positioned at (i)~1181 cm −1 , (ii)~1030 cm −1 , (iii)~950 cm −1 and (iv) 855 cm −1 appertaining to the asymmetric stretching (ν as ) vibrational modes of: (i + ii) of the Si-O-Si bonds in all the silicate tetrahedrons, TO 3 (Transverse-Optical) and LO 3 (Longitudinal-Optical) modes, respectively, and of Si-O bonds in (iii) Q 2 + Q 3 (with one and two NBOs) and (iv) Q 0 + Q 1 (with three and four NBOs) units [9,[66][67][68]. The lower intensity band at~749 cm −1 is assigned to the symmetrical stretching (ν s ) vibrations of Si-O bonds.…”

“…Over 30 years since its first implantation in 1985, 45S5 bioactive glass has been implanted into 1.5 million patients worldwide under various forms and trade names (e.g., Perioglas ® , NovaBone ® , Biogran ® , NovaMin ® , TeraSphere ® ) [2,5]. Due to their high indices of bioactivity, 45S5-based formulations have been proposed as coating materials for the bio-functionalisation of various metallic titanium-based implants [7,9], to enhance their bone-bonding ability. However, the disparity of the coefficients of thermal expansion (CTE) of 45S5 (i.e.,~14-17 × 10 −6 • C −1 ) and titanium-based (i.e.,~8.5-9.6 × 10 −6 • C −1 ) materials cannot be circumvented with ease [10], and represents a hazard for the long-term mechanical performance of the implant coating.…”

“…Furthermore, because of the burst release of high concentrations of sodium and overall excessive bio-reactivity [5,11], 45S5 bioactive glass could generate highly alkaline pH environments, which, in the absence of preconditioning procedures could lead to less than favourable biological outcomes [5,12]. More recently, alkali-free SBGs such as FastOs ® BG (mol.%: SiO 2 -38.49, CaO-36.07, P 2 O 5 -5.61, MgO-19.24, CaF 2 -0.59) have been introduced and acknowledged for their notable performances such as reduced CTEs mismatch, chemical durability, high biomineralization capacity and excellent cytocompatibility [5,9,13].…”