Chemical surface modification of hydroxyapatite for biomedical application: a review

Development of Biodegradable Osteopromotive Citrate‐Based Bone Putty

“…[ 24,48–52 ] Modification strategies to one or both phases, such as conjugation of ceramic binding groups to polymer chains or surface modification of ceramics with lactic acid oligomers, [ 53 ] isocyanates, [ 54 ] poly(amino acids), catechols, [ 52,55 ] or silanes have resulted in enhanced physical properties; however, such processes are inherently limited due to the low reactivity of ceramic surface groups and increase both cost and complexity, motivating the search for composite systems with inherent biomimetic structures. [ 52,56 ]…”

“…[24,[48][49][50][51][52] Modification strategies to one or both phases, such as conjugation of ceramic binding groups to polymer chains or surface modification of ceramics with lactic acid oligomers, [53] isocyanates, [54] poly(amino acids), catechols, [52,55] or silanes have resulted in enhanced physical properties; however, such processes are inherently limited due to the low reactivity of ceramic surface groups and increase both cost and complexity, motivating the search for composite systems with inherent biomimetic structures. [52,56] Citrate has emerged as a critical structural component of native bone, comprising 5% by weight and covering 1/6 of the inorganic bone surface, strongly associating with both the fibrous collagen organic phase and amorphous calcium phosphate (ACP) inorganic phase during bone formation, decreasing surface binding energy between the two phases and facilitating intra-and interfibrillar mineralization. [56][57][58] Further, binding of citrate to specific surfaces of HA as it undergoes crystallization from early amorphous phases serves to regulate crystal size/shape to the preferred nanocrystal morphology, preventing bulk crystal fusion and brittle mechanics.…”

“…[52,56] Citrate has emerged as a critical structural component of native bone, comprising 5% by weight and covering 1/6 of the inorganic bone surface, strongly associating with both the fibrous collagen organic phase and amorphous calcium phosphate (ACP) inorganic phase during bone formation, decreasing surface binding energy between the two phases and facilitating intra-and interfibrillar mineralization. [56][57][58] Further, binding of citrate to specific surfaces of HA as it undergoes crystallization from early amorphous phases serves to regulate crystal size/shape to the preferred nanocrystal morphology, preventing bulk crystal fusion and brittle mechanics. [58][59][60][61] Inspired by the dual-phase bridging roles of in vivo soluble citrate, we theorized that polymers directly incorporating citrate could intrinsically recapitulate the strong organic/inorganic phase binding in a biomaterial platform.…”

Effect of the Surface Modification of HAp Nanoparticles by Oleic Acid on the Properties of HDPE Nanocomposites Containing Thereof

“…their incompatibility. Many diverse techniques have been developed and used to improve the interfacial compatibility between HAp fillers and polymer matrix; mostly, this is achieved by applying various methods of modifying the filler surface, which are reviewed in [10,11]. The type of surface modifier applied is highly dependent on the nature of the matrix polymer, which can be conventional synthetic polymers (polyethylene, polypropylene, epoxy resins, etc.…”

Surface-Modified Nano-Hydroxyapatite Uniformly Dispersed on High-Porous GelMA Scaffold Surfaces for Enhanced Osteochondral Regeneration

“… 21 Previous research indicates that when the surface of modified HAp samples becomes more structurally and chemically similar to the polymer component of the polymer network in which it is used as a filler, the cross-linking process resembles more closely the cross-linking of an unfilled polymer. 22 To achieve a more uniform dispersion of n-HAp within the GelMA surface, it is advantageous to introduce methacrylate groups onto the n-HAp surface, which are the same type of groups involved in cross-linking with GelMA. Past literature has validated the reproducibility of silane coupling agents for n-HAp surface modification, 23 as well as their anti-aggregation properties.…”