Effects of crystalline phase on the biological properties of collagen–hydroxyapatite composites

In Vitro Biological Evaluation of 3-D Hydroxyapatite/Collagen (50/50 wt. (%)) Scaffolds

“…Several different factors seem to act, synergistically or interchangeably, to initiate mineral deposition in organic structures. Zhang et al 15 suggested that mineral nucleation and growth is mediated by a combination of biological, physico-chemical and biomechanical factors. The presence or absence of proteins and other substances, such as proteoglycans, can influence the nucleation phase.…”

“…Recent studies have described different methods for producing HA/Col scaffolds, among which different selfassembly methods can be highlighted [7][8][9]15,21,22 . The samples obtained by the methods described above were visually homogeneous, with a three-dimensional network and were easy to manipulate.…”

“…Moreover, they significantly enhance the expression of mature bone marker genes such as osteocalcin and bone sialoprotein 12 . Finally, HA/ Col scaffolds have shown important roles in TE, with good in vitro and in vivo results [13][14][15] , but few studies have analyzed the influence of the process parameters used for scaffold preparation on their in vitro biological functionality.…”

Composite Scaffolds for Orthopaedic Regenerative Medicine

“…The nature of these nanohydroxyapatite particles endows them with a number of distinct regenerative advantages relative to the micron-sized particles and this has been a driving factor in the move towards the hypothesis that biomimetic scaffolds fabricated using biomimetic processes may allow the development of composite scaffolds optimised to promote rapid osteogenesis in vivo. As a result, many recent studies have utilised biocompatible or bioactive dispersants, such as chitosan (Zhang et al, 2010b) or biomimetic fabrication methods for the in situ mineralisation of collagen-HA scaffolds during the fabrication process (Zhang et al, 2010a;Xu et al, 2010;Yoshida et al,2010;Kikuchi et al, 2004). One of the earliest attempts to combine biologically-occurring composite constituents with biomimetic fabrication processes to form a bone graft substitute material was carried out by Kikuchi (Kikuchi et al, 2004).…”

“…In addition, control and regulation of this process and the resulting nature of the fabricated HA can be difficult with implications on the purity and crystallinity of the resulting mineral phase. Given that HA crystallinity and purity plays a significant role in promoting bone tissue formation in vivo (Zhang et al, 2010a;ter Brugge et al, 2002), the ability to produce pure collagen-HA scaffolds of high purity and crystallinity is desirable from a tissue engineering perspective. However, a significant flaw that exists in the biomimetic fabrication approach is the assumption that an ideal optimised bone graft substitute material must mimic the composition and structure of the final bone tissue.…”