Simulated body fluid explained
Simulated body fluid should not be confused with theatrical blood.
A simulated body fluid (SBF) is a solution with an ion concentration close to that of human blood plasma, kept under mild conditions of pH and identical physiological temperature.[1] SBF was first introduced by Kokubo et al. in order to evaluate the changes on a surface of a bioactive glass ceramic.[2] Later, cell culture media (such as DMEM, MEM, α-MEM, etc.), in combination with some methodologies adopted in cell culture, were proposed as an alternative to conventional SBF in assessing the bioactivity of materials.[3]
Applications
Surface modification of metallic implants
For an artificial material to bond to living bone, the formation of bonelike apatite layer on the surface of an implant is of significant importance. The SBF can be used as an in vitro testing method to study the formation of apatite layer on the surface of implants so as to predict their in vivo bone bioactivity.[4] The consumption of calcium and phosphate ions, present in the SBF solution, results in the spontaneous growth of bone-like apatite nuclei on the surface of biomaterials in vitro. Therefore, the apatite formation on the surface of biomaterials, soaked in the SBF solution, is considered a successful development of novel bioactive materials.[5] The SBF technique for surface modification of metallic implants is usually a time-consuming process, and obtaining uniform apatite layers on substrates takes at least 7 days, with daily refreshing of the SBF solution.[6] Another approach for decreasing the coating time is to concentrate the calcium and phosphate ions in the SBF solution. Enhanced concentration of calcium and phosphate ions in SBF solution accelerates the coating process and, in the meantime, eliminates the need for regular replenishment of the SBF solution.
Gene delivery
An attempt was made to investigate the application of SBF in gene delivery.[7] Calcium phosphate nanoparticles, required for the delivery of plasmid DNA (pDNA) into the nucleus of the cells, were synthesized in a SBF solution and mixed with pDNA. The in vitro studies showed higher gene delivery efficiency for the calcium-phosphate/DNA complexes made of SBF solution than for the complexes prepared in pure water (as control).
Formulation
Ionic concentrations (mM) of blood plasma and proposed SBF formulations[8] Formulation | | | | | | | | | Buffer |
---|
Blood plasma [9] | 142.0 | 5.0 | 1.5 | 2.5 | 103.0 | 27.0 | 1.0 | 0.5 | - |
Original SBF [10] | 142.0 | 5.0 | 1.5 | 2.5 | 148.8 | 4.2 | 1.0 | 0 | Tris |
Corrected (c-SBF) [11] | 142.0 | 5.0 | 1.5 | 2.5 | 147.8 | 4.2 | 1.0 | 0.5 | Tris |
Tas-SBF [12] | 142.0 | 5.0 | 1.5 | 2.5 | 125.0 | 27.0 | 1.0 | 0.5 | Tris |
Bigi-SBF | 141.5 | 5.0 | 1.5 | 2.5 | 124.5 | 27.0 | 1.0 | 0.5 | HEPES |
Revised (r-SBF) [13] | 142.0 | 5.0 | 1.5 | 2.5 | 103.0 | 27.0 | 1.0 | 0.5 | HEPES |
Modified (m-SBF) | 142.0 | 5.0 | 1.5 | 2.5 | 103.0 | 10.0 | 1.0 | 0.5 | HEPES |
Ionized (i-SBF) | 142.0 | 5.0 | 1.0 | 1.6 | 103.0 | 27.0 | 1.0 | 0.5 | HEPES |
Improved (n-SBF) [14] | 142.0 | 5.0 | 1.5 | 2.5 | 103.0 | 4.2 | 1.0 | 0.5 | Tris | |
Notes and References
- Biomaterials . Bioactive glass ceramics: properties and applications . Kokubo . T. . 12 . 2 . 1991 . 155–163. 10.1016/0142-9612(91)90194-F. 1878450 .
- Journal of Biomedical Materials Research . Solutions able to reproduce in vivo surface-structure changes in bioactive glass–ceramic A–W . Kokubo . T. . Kushitani . H. . Sakka . S. . Kitsugi . T. . Yamamuro . T. . 24 . 1990 . 6 . 721–734. 10.1002/jbm.820240607 . 2361964 .
- Acta Biomaterialia . Cell culture medium as an alternative to conventional simulated body fluid . Lee . J. . Leng . Y. . Chow . K. . Ren . F. . Ge . X. . Wang . K. . Lu . X. . 7 . 6 . 2011 . 2615–22. 10.1016/j.actbio.2011.02.034 . 21356333 .
- Biotechnology and Bioengineering. Effect of Surface Roughness of Ti, Zr and TiZr on Apatite Precipitation from Simulated Body Fluid . Chen . Xiaobo . Nouri . Alireza . Li . Yuncang . Lin . Jiangoa . Hodgson . Peter D. . Wen . Cuie . 101 . 2 . 2008 . 378–387. 10.1002/bit.21900. 18454499 . 10949202 .
- Biomaterials. How useful is SBF in predicting in vivo bone bioactivity? . Kokubo . T. . Takadama . H. . 27 . 15 . 2006 . 2907–2915. 10.1016/j.biomaterials.2006.01.017 . 16448693.
- Journal of Biomedical Materials Research . Quasi-biological apatite film induced by titanium in a simulated body fluid . Li . P. . Ducheyne . P. . 41 . 3 . 1998 . 341–348. 10.1002/(SICI)1097-4636(19980905)41:3<341::AID-JBM1>3.0.CO;2-C. 9659601 .
- International Journal of Pharmaceutics . Calcium phosphate-mediated gene delivery using simulated body fluid (SBF). Nouri . Alireza . Castro . Rita . Santos . Jose L. . Fernandes . Cesar . Rodrigues . J. . Tomás . H. . 434 . 1–2. 2012 . 199–208. 10.1016/j.ijpharm.2012.05.066. 22664458. 1602169.
- Book: Yilmaz . Bengi . Evis . Zafer . Webster . Thomas. Yazici. Hilal . Biomedical Nanomaterials: From Design To Implementation . The Institution of Engineering and Technology . October 2016 . 3–14 . Chapter 1: Biomimetic coatings of calcium phosphates on titanium alloys . 10.1049/PBHE004E_ch1 . 9781849199650 . amp.
- Bigi. Adriana. Boanini. Elisa. Bracci. Barbara. Facchini. Alessandro. Panzavolta. Silvia. Segatti. Francesco. Sturba. Luigina. Nanocrystalline hydroxyapatite coatings on titanium: a new fast biomimetic method. Biomaterials. 26. 19. 2005. 4085–4089. 0142-9612. 10.1016/j.biomaterials.2004.10.034. 15664635.
- Kokubo. Tadashi. Takadama. Hiroaki. How useful is SBF in predicting in vivo bone bioactivity?. Biomaterials. 27. 15. 2006. 2907–2915. 0142-9612. 10.1016/j.biomaterials.2006.01.017. 16448693.
- Cui. Xinyu. Kim. Hyun-Min. Kawashita. Masakazu. Wang. Longbao. Xiong. Tianying. Kokubo. Tadashi. Nakamura. Takashi. Apatite formation on anodized Ti-6Al-4V alloy in simulated body fluid. Metals and Materials International. 16. 3. 2010. 407–412. 1598-9623. 10.1007/s12540-010-0610-x. 2010MMI....16..407C . 137643093 .
- Cüneyt Tas. A. Synthesis of biomimetic Ca-hydroxyapatite powders at 37°C in synthetic body fluids. Biomaterials. 21. 14. 2000. 1429–1438. 0142-9612. 10.1016/S0142-9612(00)00019-3. 10872772.
- Oyane. Ayako. Onuma. Kazuo. Ito. Atsuo. Kim. Hyun-Min. Kokubo. Tadashi. Nakamura. Takashi. Formation and growth of clusters in conventional and new kinds of simulated body fluids. Journal of Biomedical Materials Research. 64A. 2. 2003. 339–348. 0021-9304. 10.1002/jbm.a.10426. 12522821.
- Takadama. Hiroaki. Hashimoto. Masami. Mizuno. Mineo. Kokubo. Tadashi. Round-Robin Test of SBF for In Vitro Measurement of Apatite-Forming Ability of Synthetic Materials. Phosphorus Research Bulletin. 17. 2004. 119–125. 0918-4783. 10.3363/prb1992.17.0_119. free.