Substituted hydroxyapatite coatings of bone implants

Abstract

This review is a comprehensive overview and analysis of the most important advances in the field of substituted hydroxyapatite coatings.

Innovative Options for Bone Metastasis Treatment: An Extensive Analysis on Biomaterials-Based Strategies for Orthopedic Surgeons

“…With the purpose to obtain enhanced therapeutic effectiveness, these materials were therefore tested in many studies as drug carriers or as gene delivery systems ( Ruiz-Hernández et al, 2008 ; Liu et al, 2009 ; Vallet-Regí and Ruiz-Hernández, 2011 ; Wu and Chang, 2014 ; Gao et al, 2015 ; Santos et al, 2017 ; Köse et al, 2018 ; Afewerki et al, 2020 ). To better resemble natural bone apatite and interact with neighbor tissues, synthetic HA can include several diverse ions in place of Ca 2+ , PO 4 3– , or OH – , e.g., Na + , K + , Mg 2+, Sr 2+ , Zn 2+ , Cl – , F – , HPO 4 2– ( Kim et al, 1998 ; Vallet-Regí and Arcos, 2005 ; Landi et al, 2007 , 2008 ; Kolmas et al, 2011 ; Bornapour et al, 2013 ; Montesi et al, 2017 ; Arcos and Vallet-Regí, 2020 ). The incorporation of these ions in the HA structure limits the crystal growth and alters surface properties, thus enhancing its bioactivity and integrability with tissues; additionally, it also helps bone tissue self-healing and regeneration through the stimulation of osteoblasts and bone resident cells to form new bone when released during implant degradation ( Vallet-Regí and Salinas, 2019 ).…”

“…The incorporation of these ions in the HA structure limits the crystal growth and alters surface properties, thus enhancing its bioactivity and integrability with tissues; additionally, it also helps bone tissue self-healing and regeneration through the stimulation of osteoblasts and bone resident cells to form new bone when released during implant degradation ( Vallet-Regí and Salinas, 2019 ). For all these reasons, HA has been used not only as the pure constituent of implants but also specifically as nano-HA for coatings e.g., in Ti alloys, Ti 6 Al 4 V, and in sol-gel preparations, where bioactive responses and biocompatibility is far higher than pure HA ( Khor et al, 2004 ; Kulpetchdara et al, 2016 ; Sánchez-Salcedo et al, 2016 ; Zhou et al, 2016 ; Domínguez-Trujillo et al, 2018 ; Izquierdo-Barba et al, 2019 ; Lapaj et al, 2019 ; Robertson et al, 2019 ; Vallet-Regí and Salinas, 2019 ; Arcos and Vallet-Regí, 2020 ).…”

In Situ and Ex Situ Designed Hydroxyapatite: Bacterial Cellulose Materials with Biomedical Applications

“…The inorganic phase of the composites designed for bone replacement is usually hydroxyapatite (HAp) [7,8]. HAp is an essential element required for tissue regeneration, with the advantages of great biocompatibility, high plasticity, and remarkable mechanical properties because its chemical and crystalline structure is similar to natural bone apatite [2,9].…”

“…HAp is an essential element required for tissue regeneration, with the advantages of great biocompatibility, high plasticity, and remarkable mechanical properties because its chemical and crystalline structure is similar to natural bone apatite [2,9]. It also has an ultrafine structure and a large surface area that is advantageous for cell-biomaterial interactions and has been widely studied in applications for bone engineering [8,10].…”

Tailoring the Surface Morphology and the Crystallinity State of Cu- and Zn-Substituted Hydroxyapatites on Ti and Mg-Based Alloys

“…Ideally, the deposited coating not only should possess an antibacterial effect, but also increase bone healing and improve osseointegration. From that perspective, substituted hydroxyapatites (HA) are one of the most promising materials for biomedical coatings [ 11 , 12 , 13 ]. It has been shown that inorganic antibacterial metallic ions (e.g., Cu, Zn, and Ag) can be introduced into the HA lattice and improve its antibacterial properties [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ].…”