Zinc-containing bioactive glasses for bone regeneration, dental and orthopedic applications

Abstract

Zinc is a vital and beneficial trace element found in the human body. Though found in small proportions, zinc performs a variety of functions in relation to the immune system, cell division, fertility and the body growth and maintenance. In particular, zinc is proven to be a necessary element for the formation, mineralization, development and maintenance of healthy bones. Considering this attractive attributes of zinc, recent research has widely focused on using zinc along with silicate-based bioactive glasses for bone tissue engineering applications. This paper reviews relevant literature discussing the significance of zinc in the human body, along with its ability to enhance antibacterial effects, bioactivity and distinct physical, structural and mechanical properties of bioactive glasses. In this context, even if the present analysis is not meant to be exhaustive and only representative studies are discussed, literature results confirm that it is essential to understand the properties of zinc-containing bioactive glasses with respect to their in vitro biological behavior, possible cytotoxic effects and degradation characteristics to be able to effectively apply these glasses in bone regeneration strategies. Topics attracting increasing research efforts in this field are elaborated in detail in this review, including a summary of the structural, physical, biological and mechanical properties of zinc-containing bioactive glasses. This paper also presents an overview of the various applications in which zinc-containing bioactive glasses are considered for use as bone tissue scaffolds, bone filling granules, bioactive coatings and bone cements, and advances and remaining challenges are highlighted.

Biodegradable zinc oxide composite scaffolds promote osteochondral differentiation of mesenchymal stem cells

“…ZnO nanoparticles can be incorporated into polycaprolactone (PCL), a slow degrading material, to allow for zinc dissolution from a composite scaffold which could be beneficial for both bone and cartilage regeneration. Zinc is an essential nutrient for many physiological functions including growth, DNA synthesis, immune function, and bone metabolism and it is part of almost 300 enzymes and a large number of proteins (Balasubramanian, Strobel Leonie, Kneser, & Boccaccini Aldo, 2015;Beyersmann & Haase, 2001). Zinc mimics many insulin activities, including stimulating glucose metabolism and extracellular-signal-regulated kinases 1 and 2 (ERK1/2) activation (May & Contoreggi, 1982;Myers, Nield, & Myers, 2012).…”

ZnO quantum dots modified bioactive glass nanoparticles with pH-sensitive release of Zn ions, fluorescence, antibacterial and osteogenic properties

“…7,8 Among a large number of ions with therapeutic effects, zinc (Zn), being an important element of alkaline phosphatase (ALP) and a key mediator of bone matrix mineralization, 9 plays a significant role in bone formation. 10,11 Additionally, Zn ions show antibacterial effects, being therefore beneficial for the inhibition of infection. 12 Zinc-containing BG have shown enhanced calcified matrix deposition and ALP activity compared with BG without zinc.…”

“…The presence of ZnO in BG may delay the nucleation of HA crystals during the initial periods of immersion in SBF, but it has no significant effects on HA formation after a long period of immersion. 11 The zinc ions released from BG can be adsorbed on the active sites of BG, which therefore inhibits the deposition of apatite. The coating of ZnO QDs on the surface of BGN, playing a similar role in HA formation to the case of Zn-doped BG, delayed but not prevented the HA formation.…”

Development of a novel bioactive glass suitable for osteosarcoma‐related bone grafts

“…A key ion in the extracts that is involved in bone metabolism is zinc. It plays an active role in stimulating bone formation and has been shown to be concentrated in osteoid prior to its calcification to bone . Studies conducted on in vivo models confirm that dietary zinc enhances osteoblast differentiation while inhibiting osteoclastic differentiation and subsequent resorption .…”