Reinforcement of Calcium Phosphate Cement with Hybrid Silk Fibroin/Kappa-Carrageenan Nanofibers

Abstract

Calcium phosphate cements (CPCs) offer a promising solution for treating bone defects due to their osteoconductive, injectable, biocompatible, and bone replacement properties. However, their brittle nature restricts their utilization to non-load-bearing applications. In this study, the impact of hybrid silk fibroin (SF) and kappa-carrageenan (k-CG) nanofibers as reinforcements in CPC was investigated. The CPC composite was fabricated by incorporating electrospun nanofibers in 1, 3, and 5% volume fractions. The morphology, mineralization, mechanical properties, setting time, injectability, cell adhesion, and mineralization of the CPC composites were analyzed. The results demonstrated that the addition of the nanofibers improved the CPC mixture, leading to an increase in compressive strength (14.8 ± 0.3 MPa compared to 8.1 ± 0.4 MPa of the unreinforced CPC). Similar improvements were seen in the bending strength and work fracture (WOF). The MC3T3-E1 cell culture experiments indicated that cells attached well to the surfaces of all cement samples and tended to join their adjacent cells. Additionally, the CPC composites showed higher cell mineralization after a culture period of 14 days, indicating that the SF/k-CG combination has potential for applications as a CPC reinforcement and bone cell regeneration promoter.

Antioxidant flavonoid-loaded nano-bioactive glass bone paste: in vitro apatite formation and flow behavior

“…In other words, precipitation appears to be caused by a reaction between Ca 2+ and PO 4 3− ions released from the glass particles, followed by precipitation. 8,51…”

“…Accordingly, the following eqn (2) was used for calculating the injectability (%). 8 Injectability ð%Þ ¼ extruded paste volume total paste volume  100…”

“…In other words, precipitation appears to be caused by a reaction between Ca 2+ and PO 4 3− ions released from the glass particles, followed by precipitation. 8,51 It has been found that the intensity of apatite peaks increases by increasing the immersion time through the dissolution and release of calcium and phosphate ions from BG, as well as the precipitation and densication of the apatite phase. The XRD pattern (Fig.…”

“…52,55,56 The signals of the (CO 3 ) 2− group substituted for the (PO 4 ) 3− group in the apatite lattice were found at 870, 1420, and 1460 cm −1 . 8,51,57 When the Q content increased, the single C-O stretching band at 1420 cm −1 changed into a twin (at 1420 and 1460 cm −1 ), while the absorption intensity of the C-O band at 870 cm −1 increased. 45 The SEM micrographs and their related EDS patterns of the pastes before and aer 14 days of immersion in SBF solution are shown in Fig.…”

“…7 According to previous studies, adding a polymeric phase also improved the injectability of cement. 8,9 In another research study, glycerol was added to cement to enhance injectability; however, it extended the setting time. 10 On the one hand, a long setting reaction is disadvantageous because an unset cement cannot withstand local stresses and consequently, can cause inammatory response from disintegration.…”