Nanohydroxyapatite Effect on the Degradation, Osteoconduction and Mechanical Properties of Polymeric Bone Tissue Engineered Scaffolds

Abstract

BACKGROUNDStatistical reports show that every year around the world approximately 15 million bone fractures occur; of which up to 10% fail to heal completely and hence lead to complications of non-union healing. In the past, autografts or allografts were used as the “gold standard” of treating such defects. However, due to various limitations and risks associated with these sources of bone grafts, other avenues have been extensively investigated through which bone tissue engineering; in particular engineering of synthetic bone graft substitutes, has been recognised as a promising alternative to the traditional methods.METHODSA selective literature search was performed.RESULTSBone tissue engineering offers unlimited supply, eliminated risk of disease transmission and relatively low cost. It could also lead to patient specific design and manufacture of implants, prosthesis and bone related devices. A potentially promising building block for a suitable scaffold is synthetic nanohydroxyapatite incorporated into synthetic polymers. Incorporation of nanohydroxyapatite into synthetic polymers has shown promising bioactivity, osteoconductivity, mechanical properties and degradation profile compared to other techniques previously considered.CONCLUSIONScientific research, through extensive physiochemical characterisation, in vitro and in vivo assessment has brought together the optimum characteristics of nanohydroxyapatite and various types of synthetic polymers in order to develop nanocomposites of suitable nature for bone tissue engineering. The aim of the present article is to review and update various aspects involved in incorporation of synthetic nanohydroxyapatite into synthetic polymers, in terms of their potentials to promote bone growth and regeneration in vitro, in vivo and consequently in clinical applications.

Alginate-nanohydroxyapatite hydrogel system: Optimizing the formulation for enhanced bone regeneration

“…The osteoconductive/osteoinductive, biocompatibility and bioactivity properties of nanoHA materials [7,28] combined with the injectability, biocompatibility and biodegradation properties of Alg polymers [29,30] can improve the physic-chemical and cell adhesion/tissue development of the attained composites, enhancing bone tissue regeneration [31][32][33]. However, these properties could be dependent on the amount of ceramic nanoparticles used within the polymer-based composite, as observed by other authors [21][22][23]. In this context, in the present study, the influence of nanoHA content on an alginate-based hydrogel system was studied, regarding its physic-chemical and biological properties, within in vitro and ex vivo studies, aiming to optimize the combination of Alg and nanoHA within the established system for maximizing the bone regeneration process.…”

“…Once nanoHA is gradually degraded, it releases calcium (Ca 2+ ) and phosphate (PO 4 −3 ) ions, which can modulate cellular behavior within the microenvironment, through different signaling pathways, influencing the bone mineralization process and bonding to the surrounding tissues [21]. Accordingly, some authors have reported that the level of solubility, bonelike apatite layer formation, cell attachment, proliferation and differentiation and, ultimately, bone growth rate, could be dependent on the concentration of nanoHA incorporated into polymer-based composites [21][22][23].…”

Composite clinoptilolite/PCL‐PEG‐PCL scaffolds for bone regeneration: In vitro and in vivo evaluation

“…Significantly higher weight loss was observed for PC‐20 having greater CLN content than PC‐0 (Table S2). This suggests that the plasticizing effect of CLN on PCEC chains might have resulted in further bulk degradation due to increased water resorption and thus movement of polymer chains (Salmasi, Nayyer, Seifalian, & Blunn, ).…”

A specific affinity cyclic peptide enhances the adhesion, expansion and proliferation of rat bone mesenchymal stem cells on β‑tricalcium phosphate scaffolds

“…In addition, cyclic peptides have low inherent toxicity, can be efficiently synthesized and easily labeled (25). Salmasi et al (53) reported that the number of seed cells, and cell adhesion and expansion on biomaterial scaffolds determined the ability of bone tissue regeneration in bone tissue engineering.…”