Injectable thermosensitive hydrogel composite with surface-functionalized calcium phosphate as raw materials

Abstract

In this study, L-lactide was used to modify the tricalcium phosphate (β-TCP) and tetracalcium phosphate (TTCP) surface which can form functionalized poly(l-lactic acid) (PLLA)-grafted β-TCP (g-β-TCP) and PLLA-grafted TTCP (g-TTCP) particles. The g-β-TCP and g-TTCP obtained were incorporated into a PEG-PCL-PEG (PECE) matrix to prepare injectable thermosensitive hydrogel composites. The morphology of the hydrogel composites showed that the g-β-TCP and g-TTCP particles dispersed homogeneously into the polymer matrix, and each hydrogel composite had a three-dimensional network structure. Rheologic analysis showed that the composite had good thermosensitivity. Changes in calcium concentration and pH in simulated body fluid solutions confirmed the feasibility of surface-functionalized calcium phosphate for controlled release of calcium. All the results indicate that g-β-TCP/PECE and g-TTCP/PECE hydrogels might be a promising protocol for tissue engineering.

Novel multicomponent organic–inorganic WPI/gelatin/CaP hydrogel composites for bone tissue engineering

“…Future work should focus on improving homogeneity. One of the strategies to improve the distribution of ceramic fillers in polymeric matrices is their functionalization or surface modification (Gao et al, ). A second possible approach is to alter the zeta potential of the calcium phosphate particles by, for instance, changing the pH of solution (Chen et al, ).…”

Nanostructured Biomaterials for Bone Regeneration

“…Initial attempts consisted of the direct adsorption or crosslinking of biomolecules to implants, which resulted in suboptimal outcomes, mostly due to burst release and molecule denaturation (Fan et al, 2012). Matsumoto et al, 2004;Dong et al, 2007;Habraken et al, 2007;LeGeros, 2008;Yuan et al, 2010;Xie et al, 2010;Bose and Tarafder, 2012;Jeon et al, 2012;Fielding and Bose, 2013;Fan et al, 2014;Wen et al, 2017 Metallic or metalloid oxides (e.g., silica)…”

“…Commonly used ceramics include CaPs, such as HA and TCP. In the first generation of HA-based delivery systems, HA was directly adsorbed with bioactive molecules such as BMP-2 ( Matsumoto et al, 2004 ; Dong et al, 2007 ; Xie et al, 2010 ), however, side effects associated with their burst release quickly demanded alternative strategies ( Xie et al, 2010 ), such as chemically bonding bioactive molecules to the surface of the ceramic particles, which provides a more controlled and sustained release over time ( Fan et al, 2014 ). The surface of CaP particles can be functionalized to bind a wide array of bioactive molecules for bone regeneration ( Bose and Tarafder, 2012 ).…”

Injectable Organic-Inorganic Biocomposites for Bone Tissue Regeneration - A Mini Review

“…Halloysite nanotubes Chemically Adipic acid dihydrazide [45] Methacrylate/Gelatin β-TCP Chemically -UV Photo-initiator 12 by UV [9] Poly [41] [40]…”

“…To enhance bioactivity, osteoconductivity and bone forming ability, as well mechanical stability and biodegradation behavior of the injectable hydrogel matrix, bioactive inorganic fillers are usually incorporated [1,4,30,31,32]. The main bioactive inorganic compounds are calcium phosphates -hydroxyapatite (HAp) [2,13,14,15,16,17,18,19,20,25,36,37,38,39,40], biphasic calcium phosphates (BCP) [24,29,32,33], tetracalcium phosphate (TTCP) [41], tricalcium phosphates (α-TCP, β-TCP) [9,28,37,41], calcium phosphate cements (CPC) [23,42], bioactive glass [30,43,44] and nanoclays (halloysite nanotubes) [45]. Bioactive inorganic fillers are used to improve the mechanical strength, bioactivity, osteoconductivity, osteoinductivity, protein adhesion and in vivo absorption of the injectable biocomposites [15,22,25,30,33,37,43,44,48,…”