Examining porous bio-active glass as a potential osteo-odonto-keratoprosthetic skirt material

Abstract

Bio-active glass has been developed for use as a bone substitute with strong osteo-inductive capacity and the ability to form strong bonds with soft and hard tissue. The ability of this material to enhance tissue in-growth suggests its potential use as a substitute for the dental laminate of an osteo-odonto-keratoprosthesis. A preliminary in vitro investigation of porous bio-active glass as an OOKP skirt material was carried out. Porous glass structures were manufactured from bio-active glasses 1-98 and 28-04 containing varying oxide formulation (1-98, 28-04) and particle size range (250-315 μm for 1-98 and 28-04a, 315-500 μm for 28-04b). Dissolution of the porous glass structure and its effect on pH was measured. Structural 2D and 3D analysis of porous structures were performed. Cell culture experiments were carried out to study keratocyte adhesion and the inflammatory response induced by the porous glass materials. The dissolution results suggested that the porous structure made out of 1-98 dissolves faster than the structures made from glass 28-04. pH experiments showed that the dissolution of the porous glass increased the pH of the surrounding solution. The cell culture results showed that keratocytes adhered onto the surface of each of the porous glass structures, but cell adhesion and spreading was greatest for the 98a bio-glass. Cytokine production by all porous glass samples was similar to that of the negative control indicating that the glasses do not induce a cytokine driven inflammatory response. Cell culture results support the potential use of synthetic porous bio-glass as an OOKP skirt material in terms of limited inflammatory potential and capacity to induce and support tissue ingrowth.

Simultaneous mechanical property and biodegradation improvement of wollastonite bioceramic through magnesium dilute doping

“…Since Hench et al firstly discovered Bioglasss which was proved to possess excellent bioactivity and osteoconductivity in the early 1970s (Hench et al, 1971), Ca-silicate bioactive glasses, glass-ceramics, and bioceramics have been widely studied for their potential applications as hard tissue repair materials (De Aza et al, 2000;Gerhardt and Boccaccini, 2010;Kokubo et al, 1986;Sprio et al, 2009), special implants or prosthesis Vitale-Brovarone, 2014, 2015;Huhtinen et al, 2013), as well as drug delivery (Soundrapandian et al, 2014). For bone regeneration, the artificial materials need to meet the requirements of good osteoconduction, osteoinduction, as well as controllable bioactivity and degradation (Hench and Polak, 2002).…”

How can bioactive glasses be useful in ocular surgery?

“…In 2013, Huhtinen et al investigated two experimental silico‐boro‐phosphate BGs of different compositions (1–98: 5.9Na 2 O–7.1K 2 O–7.6MgO–23.9CaO–0.9B 2 O 3 −0.9P 2 O 5 −53.8SiO 2 ; 28‐04: 4.9Na 2 O–7.2K 2 O–9.0MgO–16.2CaO–2.6B 2 O 3 −60.1SiO 2 , mol %) as potential substitutes of the tooth‐derived skirt of the OOKP. The glasses were produced by melting‐quenching route, crushed and sieved into the 250–315 and 315–500 µm size ranges to assess the influence of different dimensional ranges besides that associated to composition; the particles were then sintered in a graphite mold into ring‐shaped structures with interconnected porosity.…”

“…The use of a partially absorbable orbital implant able to increase its porosity in vivo , thereby allowing an improved fibrovascularization postoperatively, represents a fascinating concept; however, this approach poses several problems which should be carefully and critically examined, especially concerning the kinetics of socket volume replacement by tissue while the implant resorbs and the ocular prosthesis motility in the partial or total absence of an orbital implant that can transfer movement to it. In the field of artificial cornea, resorption of the porous skirt around the optical core is an unwanted effect that would lead to the loosening of the keratoprosthesis; this problem was the major reason why synthetic alternatives to the tooth‐derived skirt of Strampelli's OOKP have been proposed, including BG‐based materials . Therefore, the use of BGs and BGCs able to maintain adequate integrity over time in vivo is recommended for this specific application.…”

“…If porous BG implants are pursued, a number of methods involving the use of pore‐forming agents, surfactant‐assisted sol–gel methods (in the case of MBGs) and rapid prototyping techniques are at the researchers' disposal. Sintering of relatively large glass particles (250–500 μm) without the use of pore formers can be performed (the final porosity derives from the interparticle void spaces among the original glass particles) . The deposition of a thin BG coating on a substrate ocular device with adequate morphostructural characteristics in order to impart it a specific added value (e.g., antibacterial effect) is a valuable strategy.…”

“…In 2013, Huhtinen et al 61 , mol %) as potential substitutes of the toothderived skirt of the OOKP. The glasses were produced by melting-quenching route, crushed and sieved into the 250-315 and 315-500 mm size ranges to assess the influence of different dimensional ranges besides that associated to composition; the particles were then sintered in a graphite mold into ring-shaped structures with interconnected porosity.…”