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. 2018 Jul 18;8(45):25745-25753.
doi: 10.1039/c8ra03957g. eCollection 2018 Jul 16.

Fabrication of strontium/calcium containing poly(γ-glutamic acid) - organosiloxane fibrous hybrid materials for osteoporotic bone regeneration

Chunxia Gao  1 , Ke Zhao  1 , Yaping Wu  1 , Qiang Gao  1   2 , Peizhi Zhu  1
Affiliations

Fabrication of strontium/calcium containing poly(γ-glutamic acid) - organosiloxane fibrous hybrid materials for osteoporotic bone regeneration

Chunxia Gao et al. RSC Adv. .

Abstract

Recent researches have proved that combination of several therapeutic metal ions, such as silicate (Si), calcium (Ca), strontium (Sr) and so on, with biomaterials may have promising effects for stimulating bone regeneration. In the present study, the Sr/Ca containing silicate hybrid materials (Sr/Ca-γ-PGA-silica) with a mimetic native extracellular matrix (ECM) structure have been developed by electrospinning. With the aim to promote the solubility of γ-PGA in aqueous-based solution and introduce Sr/Ca elements into the prepared hybrid materials, SrCO3 and CaCO3 were employed due to their nontoxicity and no by-products during chemical reaction between γ-PGA and SrCO3/CaCO3. Results of SEM, EDX and elemental mapping images showed that Sr and Ca have been successfully incorporated into the prepared fibrous hybrid materials with homogeneous dispersion. Results of ICP-AES revealed that there was continuous Si, Sr and Ca ion release behavior of Sr/Ca-γ-PGA-silica hybrid materials in Tris-HCl buffer solution and the Si ions release rate can be tailored by adjusting the molar ratio of Sr to Ca. Immersion of Sr/Ca-γ-PGA-silica hybrid materials in a simulated body fluid (SBF) resulted in the formation of an apatite-like surface layer within 3 days, indicating their excellent bioactivity. In addition, the prepared Sr/Ca-γ-PGA-silica hybrid materials supported the proliferation and alkaline phosphatase (ALP) activity of osteoblast in vitro, showing their good biocompatibility. Altogether, the results indicated that the prepared Sr/Ca-γ-PGA-silica hybrid materials with an adjusted ionic release behavior have great potential for providing an excellent ECM for osteoporotic bone regeneration.

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Conflict of interest statement

There are no conflicts to declare.

Figures

Fig. 1
Fig. 1. Morphological and compositions of prepared Sr/Ca-γ-PGA-silica hybrid materials. (a) SEM images. (b) EDX elemental spectrum. Elemental mapping images of the silicon (c), strontium (d) and calcium (e).
Fig. 2
Fig. 2. (a) ATR-FTIR spectra of protonated γ-PGA (H-γ-PGA, raw material), GPTMS and prepared Sr/Ca-γ-PGA-silica hybrid materials; (b) XRD of CaCO3 and SrCO3 (raw materials, the spectra of CaCO3 and SrCO3 are shown as references), protonated γ-PGA (H-γ-PGA, raw material) and prepared Sr/Ca-γ-PGA-silica hybrid materials.
Fig. 3
Fig. 3. 29Si MAS-NMR spectra of electrospun Ca-γ-PGA-silica, Sr-γ-PGA-silica and Sr/Ca-γ-PGA-silica hybrid materials.
Fig. 4
Fig. 4. Mechanical response in tension of electrospun γ-PGA, Ca-γ-PGA-silica, Sr-γ-PGA-silica and Sr/Ca-γ-PGA-silica hybrid materials.
Fig. 5
Fig. 5. SEM images and EDX spectra of (a and a′) Ca-γ-PGA-silica; (b and b′) Sr-γ-PGA-silica and (c and c′) Sr/Ca-γ-PGA-silica hybrid materials.
Fig. 6
Fig. 6. Si, Ca and Sr ions released curves of electrospun Ca-γ-PGA-silica, Sr-γ-PGA-silica and Sr/Ca-γ-PGA-silica hybrid materials (a) Si; (b) Ca and (C) Sr.
Fig. 7
Fig. 7. Response of MC3T3-E1 cells to fibrous Ca-γ-PGA-silica, Sr-γ-PGA-silica and Sr/Ca-γ-PGA-silica hybrid materials, and to tissue culture plastic (TCP) control substrates: (a) cell proliferation as a function of incubation time; (b) alkaline phosphatase (ALP) activity of MC3T3-E1 cells on the cell-seeded scaffolds and TCP control after incubation times of 5, 10, 14 and 21 days; *significant difference between pairs of substrates shown (p < 0.05). (Mean ± SD; n = 3).
Fig. 8
Fig. 8. SEM images of MC3T3-E1 cells morphology evolutions on the fibrous hybrid materials (a, a′ and a′′) Ca-γ-PGA-silica; (b, b′ and b′′) Sr/Ca-γ-PGA-silica and (c, c′ and c′′) Sr-γ-PGA-silica after incubation for 1 day (a–c); 3 days (a′–c′) and 14 days (a′′–c′′).
Fig. 9
Fig. 9. EDX elemental spectra of hybrid materials and elemental mapping images of the silicon, strontium and calcium after incubation of 14 days (a) Ca-γ-PGA-silica; (b) Sr/Ca-γ-PGA-silica and (c) Sr-γ-PGA-silica.
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References

    1. Kanis J. A. Rd M. L. Christiansen C. Johnston C. C. Khaltaev N. J. Bone Miner. Res. 1994;9:1137–1141. doi: 10.1002/jbmr.5650090802. - DOI - PubMed
    1. Kanis J. A. Lancet. 2002;359:1929–1936. doi: 10.1016/S0140-6736(02)08761-5. - DOI - PubMed
    1. Crandall C. J. Womens Health Gend. Based Med. 2002;11:211–224. doi: 10.1089/152460902753668420. - DOI - PubMed
    1. Akesson K. Bull. W. H. O. 2003;81:657–664. - PMC - PubMed
    1. Black L. J. and Cullinan G. J., Pharmaceutical compositions containing a bisphosphonate and an anti-resorptive agent for inhibiting bone loss, EP 0693285 A2, 1996