Intrinsic Antibacterial Borosilicate Glasses for Bone Tissue Engineering Applications

Abstract

Three novel borosilicate bioactive glasses (BBGs) were prepared and used to investigate their bioactive and antibacterial properties. The BBGs were prepared by melt-quenching using different glass modifiers, i.e. Mg 2+ , Ca 2+ , and Sr 2+ , and their amorphous nature was confirmed by X-ray diffraction. Scanning electron microscopy with energy dispersive X-ray spectroscopy allowed the visualization of apatite-like structures upon 7 days of immersion in simulated body fluid. BBG-Ca generated surface structures with a Ca/P ratio ≈1.67, while the surface of the BBG-Sr was populated with structures with a Sr/P ratio ≈1.7. Moreover, bacterial tests showed that the BBG-Mg and BBG-Sr glasses (at concentrations of 9, 18, 36, and 72 mg/ mL) present antibacterial characteristics. In particular, BBG-Sr, at concentrations of 9 mg/mL, exhibited bacteriostatic activity against Pseudomonas aeruginosa, and at concentrations ≥18 mg/mL it was able to eradicate this bacterium. These results evidence an antibacterial activity dependent on the BBGs composition, concentration, and bacterial species. Cellular studies showed that the developed BBGs do not present a statistically significant cytotoxic effect against Saos-2 cells after 3 days of culture, showing better performance (in the cases of BBG-Ca and BBG-Sr) than commercial 45S5 Bioglass up to 7 days of culture. Overall, this study demonstrates that BBGs can be effectively designed to combine bioactivity and intrinsic antibacterial activity targeting bone tissue engineering applications.

Reinforcement of poly-l-lactic acid electrospun membranes with strontium borosilicate bioactive glasses for bone tissue engineering

“…We found that the presence of BBG-Sr glass particles improved the osteogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) and induced the formation of mineralised tissue. We also demonstrated that BBG-Sr, at concentrations P18 mg/mL it was able to eradicate Pseudomonas aeruginosa bacterium [26]. Numerous reports have already associated Sr 2+ with bone therapeutic potential [19].…”

Substituted Borosilicate Glasses with Improved Osteogenic Capacity for Bone Tissue Engineering

“…The effect of BBGs' concentration on cell viability and proliferation was studied on a previous work (29,30).…”

“…The composition of BBGs was confirmed in a prior work by the use of X-ray fluorescence and follows the general formula 0.05Na 2 OxMgOyCaO(0.35-x-y)SrO0.20B 2 O 3 0.40SiO 2 (molar ratio, where x, y = 0.35 or 0.00, and x ≠ y). (30) Moreover, studies after immersion in SBF, showed that the studied BBGs are bioactive due to the formation of bone-like apatite structures onto their surface, and the constant release of ions to the reaction media over time (29).…”

Comprehensive Survey on Nanobiomaterials for Bone Tissue Engineering Applications

“…Bioglass nanoparticles were also used with bacterially derived poly(3-hydroxybutyrate) to fabricate bioactive composite film using a fermentation technique [ 275 ]. Different glass modifiers (Mg 2+ , Ca 2+ , and Sr 2+ ) were used to prepare borosilicate bioactive glasses through a melt-quenching technique which showed good antibacterial properties [ 276 ]. Poly(propylene fumarate) (PPF) was used to functionalize bioglass particles that enhance the bioactivity and cell adhesion, proliferation, and bone regeneration [ 277 ].…”