Skip to main content

Morphology, mechanical properties, and mineralization of rigid thermoplastic polyurethane/hydroxyapatite scaffolds for bone tissue applications: effects of fabrication approaches and hydroxyapatite size

Abstract

Rigid thermoplastic polyurethane (TPU)/hydroxyapatite (HA) scaffolds were prepared with micro HA (mHA) and nano HA (nHA) particles, respectively, via the thermally induced phase separation method. The effects of solvent and co-solvent, addition of sodium chloride (NaCl) porogen, and HA particle size were studied together with the morphology, compressive properties, and mineralization behavior of the scaffolds. Depending on the solvent, co-solvent, or porogen used, different porous structures were produced. In particular, a ladder-like morphology was obtained when dioxane (Di) was used as the solvent, whereas an interconnected porous structure was obtained by using dioxane and deionized water (DiW) as co-solvents. Rectangular pores with interconnected channels on the pore walls were achieved by using NaCl crystals as porogens. The TPU/nHA scaffolds showed stronger compressive properties than the TPU/mHA scaffolds and the pure TPU scaffolds. The scaffolds prepared using dioxane and water as co-solvents exhibit the greatest compressive modulus. Furthermore, TPU scaffolds with nHA particles had the ability to form bone apatite when soaked in simulated body fluid (SBF). After being soaked in SBF for 3 weeks, the weight percentage of formed apatite in the TPU/nHA-DiW scaffold was 9.2 %wt of the initial TPU content. Preliminary cytotoxicity tests were conducted using NIH 3T3 fibroblast cells. The high survival rate of these cells and the mineralization behavior suggest biocompatibility and high potential of these composites being used in bone tissue engineering applications.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13

References

  1. Brighton CT, Shaman P, Heppenstall RB, Esterhai JL, Pollack SR, Friedenberg ZB (1995) Tibial nonunion treated with direct-current, capacitive coupling, or bone-graft. Clin Orthop Relat R 321:223–234

    Google Scholar 

  2. Fernyhough JC, Schimandle JJ, Weigel MC, Edwards CC, Levine AM (1992) Chronic donor site pain complicating bone-graft harvesting from the posterior iliac crest for spinal-fusion. Spine 17:1474–1480

    Article  Google Scholar 

  3. Giannoudis PV, Dinopoulos H, Tsiridis E (2005) Bone substitutes: an update. Injury 36:20–27

    Article  Google Scholar 

  4. Langer R, Vacanti JP (1993) Tissue engineering. Science 260:920–926

    Article  Google Scholar 

  5. Mikos AG, Thorsen AJ, Czerwonka LA et al (1994) Preparation and characterization of poly(l-lactic acid) foams. Polymer 35:1068–1077

    Article  Google Scholar 

  6. Nakamatsu J, Torres FG, Troncoso OP, Yuan ML, Boccaccini AR (2006) Processing and characterization of porous structures from chitosan and starch for tissue engineering scaffolds. Biomacromolecules 7:3345–3355

    Article  Google Scholar 

  7. Wang L, Shi J, Liu L, Secret E, Chen Y (2011) Fabrication of polymer fiber scaffolds by centrifugal spinning for cell culture studies. Microelectron Eng 88:1718–1721

    Article  Google Scholar 

  8. Park SA, Kim HJ, Lee SH et al (2011) Fabrication of nano/microfiber scaffolds using a combination of rapid prototyping and electrospinning systems. Polym Eng Sci 51:1883–1890

    Article  Google Scholar 

  9. Corre YM, Maazouz A, Duchet J, Reignier J (2011) Batch foaming of chain extended PLA with supercritical CO2: influence of the rheological properties and the process parameters on the cellular structure. J Supercrit Fluid 58:177–188

    Article  Google Scholar 

  10. Kramschuster A, Turng LS (2010) An Injection molding process for manufacturing highly porous and interconnected biodegradable polymer matrices for use as tissue engineering scaffolds. J Biomed Mater Res B 92B:366–376

    Google Scholar 

  11. Rowlands AS, Lim SA, Martin D, Cooper-White JJ (2007) Polyurethane/poly(lactic-co-glycolic) acid composite scaffolds fabricated by thermally induced phase separation. Biomaterials 28:2109–2121

    Article  Google Scholar 

  12. He LM, Zhang YQ, Zeng X et al (2009) Fabrication and characterization of poly(l-lactic acid) 3D nanofibrous scaffolds with controlled architecture by liquid–liquid phase separation from a ternary polymer-solvent system. Polymer 50:4128–4138

    Article  Google Scholar 

  13. Lo H, Ponticiello MS, Leong KW (1995) Fabrication of controlled release biodegradable foams by phase separation. Tissue Eng 1:15–28

    Article  Google Scholar 

  14. Geiger M, Li RH, Friess W (2003) Collagen sponges for bone regeneration with rhBMP-2. Adv Drug Deliver Rev 55:1613–1629

    Article  Google Scholar 

  15. Li C, Wang LL, Yang Z, Kim G, Chen HF, Ge ZG (2012) A viscoelastic chitosan-modified three-dimensional porous poly(l-Lactide-co-epsilon-caprolactone) scaffold for cartilage tissue engineering. J Biomat Sci-Polym E 23:405–424

    Article  Google Scholar 

  16. Montjovent MO, Mark S, Mathieu L et al (2008) Human fetal bone cells associated with ceramic reinforced PLA scaffolds for tissue engineering. Bone 42:554–564

    Article  Google Scholar 

  17. Mondrinos MJ, Dembzynski R, Lu L et al (2006) Porogen-based solid freeform fabrication of polycaprolactone-calcium phosphate scaffolds for tissue engineering. Biomaterials 27:4399–4408

    Article  Google Scholar 

  18. Lian C, Wei L, Yilin C (2012) Modification of fibrous PLGA scaffold or PLGA micro-particles with tripolyphosphate nanoparticles. J Tissue Eng Regen M 6:214

    Article  Google Scholar 

  19. Buschmann J, Harter L, Gao SP et al (2012) Tissue engineered bone grafts based on biomimetic nanocomposite PLGA/amorphous calcium phosphate scaffold and human adipose-derived stem cells. Injury 43:1689–1697

    Article  Google Scholar 

  20. Hofmann A, Ritz U, Verrier S et al (2008) The effect of human osteoblasts on proliferation and neo-vessel formation of human umbilical vein endothelial cells in a long-term 3D co-culture on polyurethane scaffolds. Biomaterials 29:4217–4226

    Article  Google Scholar 

  21. McClure MJ, Wolfe PS, Rodriguez IA, Bowlin GL (2011) Bioengineered vascular grafts: improving vascular tissue engineering through scaffold design. J Drug Deliv Sci Tec 21:211–227

    Google Scholar 

  22. Amoroso NJ, D’Amore A, Hong Y, Rivera CP, Sacks MS, Wagner WR (2012) Microstructural manipulation of electrospun scaffolds for specific bending stiffness for heart valve tissue engineering. Acta Biomater 8:4268–4277

    Article  Google Scholar 

  23. Hausner T, Schmidhammer R, Zandieh S et al (2007) Nerve regeneration using tubular scaffolds from biodegradable polyurethane. Acta Neurochir Suppl 100:69–72

    Article  Google Scholar 

  24. Heo DN, Yang DH, Lee JB et al (2013) Burn-wound healing effect of gelatin/polyurethane nanofiber scaffold containing silver-sulfadiazine. J Biomed Nanotechnol 9:511–515

    Article  Google Scholar 

  25. Yoshii T, Hafeman AE, Nyman JS et al (2010) A sustained release of lovastatin from biodegradable elastomeric polyurethane scaffolds for enhanced bone regeneration. Tissue Eng Part A 16:2369–2379

    Article  Google Scholar 

  26. Jack KS, Velayudhan S, Luckman P, Trau M, Grondahl L, Cooper-White J (2009) The fabrication and characterization of biodegradable HA/PHBV nanoparticle-polymer composite scaffolds. Acta Biomater 5:2657–2667

    Article  Google Scholar 

  27. Duan B, Wang M (2010) Customized Ca-P/PHBV nanocomposite scaffolds for bone tissue engineering: design, fabrication, surface modification and sustained release of growth factor. J R Soc Interface 7:S615–S629

    Article  Google Scholar 

  28. Boccaccini AR, Maquet V (2003) Bioresorbable and bioactive polymer/bioglass (R) composites with tailored pore structure for tissue engineering applications. Compos Sci Technol 63:2417–2429

    Article  Google Scholar 

  29. Habibovic P, Gbureck U, Doillon CJ, Bassett DC, van Blitterswijk CA, Barralet JE (2008) Osteoconduction and osteoinduction of low-temperature 3D printed bioceramic implants. Biomaterials 29:944–953

    Article  Google Scholar 

  30. Stevens MM, George JH (2005) Exploring and engineering the cell surface interface. Science 310:1135–1138

    Article  Google Scholar 

  31. Andric T, Wright LD, Taylor BL, Freeman JW (2012) Fabrication and characterization of three-dimensional electrospun scaffolds for bone tissue engineering. J Biomed Mater Res A 100A:2097–2105

    Article  Google Scholar 

  32. Venugopal JR, Low S, Choon AT, Kumar AB, Ramakrishna S (2008) Nanobioengineered electrospun composite nanofibers and osteoblasts for bone regeneration. Artif Organs 32:388–397

    Article  Google Scholar 

  33. Yang DZ, Jin Y, Ma GP, Chen XM, Lu FM, Nie J (2008) Fabrication and characterization of chitosan/PVA with hydroxyapatite biocomposite nanoscaffolds. J Appl Polym Sci 110:3328–3335

    Article  Google Scholar 

  34. Sheikh FA, Kanjwal MA, Macossay J, Barakat NAM, Kim HY (2012) A simple approach for synthesis, characterization and bioactivity of bovine bones to fabricate the polyurethane nanofiber containing hydroxyapatite nanoparticle. Express Polym Lett 6:41–53

    Article  Google Scholar 

  35. Wang L, Zuo Y, Zou Q, Li YB (2011) Effect of composition on physical-chemical properties and biological properties of hydroxyapatite/aliphatic polyurethane scaffolds for bone tissue engineering. Chem J Chinese Univ 32:2453–2459

    Google Scholar 

  36. Kokubo T (1991) Bioactive glass-ceramics—properties and applications. Biomaterials 12:155–163

    Article  Google Scholar 

  37. Kokubo T, Ito S, Huang ZT et al (1990) Ca, P-rich layer formed on high-strength bioactive glass-ceramic a-W. J Biomed Mater Res 24:331–343

    Article  Google Scholar 

  38. Ohtsuki C, Kushitani H, Kokubo T, Kotani S, Yamamuro T (1991) Apatite formation on the surface of ceravital-type glass-ceramic in the body. J Biomed Mater Res 25:1363–1370

    Article  Google Scholar 

  39. Legeros RZ, Lin S, Rohanizadeh R, Mijares D, Legeros JP (2003) Biphasic calcium phosphate bioceramics: preparation, properties and applications. J Mater Sci-Mater M 14:201–209

    Article  Google Scholar 

  40. Li PJ, Ohtsuki C, Kokubo T, Nakanishi K, Soga N, Degroot K (1994) The role of hydrated silica, titania, and alumina in inducing apatite on implants. J Biomed Mater Res 28:7–15

    Article  Google Scholar 

  41. Deplaine H, Lebourg M, Ripalda P et al (2013) Biomimetic hydroxyapatite coating on pore walls improves osteointegration of poly(l-lactic acid) scaffolds. J Biomed Mater Res B 101B:173–186

    Article  Google Scholar 

  42. Peng F, Yu XH, Wei M (2011) In vitro cell performance on hydroxyapatite particles/poly(l-lactic acid) nanofibrous scaffolds with an excellent particle along nanofiber orientation. Acta Biomater 7:2585–2592

    Article  Google Scholar 

  43. Kokubo T, Takadama H (2006) How useful is SBF in predicting in vivo bone bioactivity? Biomaterials 27:2907–2915

    Article  Google Scholar 

  44. Panda RN, Hsieh MF, Chung RJ, Chin TS (2003) FTIR, XRD, SEM and solid state NMR investigations of carbonate-containing hydroxyapatite nano-particles synthesized by hydroxide-gel technique. J Phys Chem Solids 64:193–199

    Article  Google Scholar 

  45. Mobasherpour I, Heshajin MS, Kazemzadeh A, Zakeri M (2007) Synthesis of nanocrystalline hydroxyapatite by using precipitation method. J Alloy Compd 430:330–333

    Article  Google Scholar 

  46. Schugens C, Maquet V, Grandfils C, Jerome R, Teyssie P (1996) Biodegradable and macroporous polylactide implants for cell transplantation. 1. Preparation of macroporous polylactide supports by solid–liquid phase separation. Polymer 37:1027–1038

    Article  Google Scholar 

  47. Wang XH, Shi SA, Guo G et al (2011) Preparation and characterization of a porous scaffold based on poly(d, l-lactide) and N-hydroxyapatite by phase separation. J Biomat Sci-Polym E 22:1917–1929

    Article  Google Scholar 

  48. Hench LL, Wilson J (1993) An introduction to bioceramics. World Scientific, London and Singapore

    Book  Google Scholar 

  49. Yu SC, Hariram KP, Kumar R, Cheang P, Aik KK (2005) In vitro apatite formation and its growth kinetics on hydroxyapatite/polyetheretherketone biocomposites. Biomaterials 26:2343–2352

    Article  Google Scholar 

  50. Lluch AV, Ferrer GG, Pradas MM (2009) Surface modification of P(EMA-co-HEA)/SiO2 nanohybrids for faster hydroxyapatite deposition in simulated body fluid? Colloid Surface B 70:218–225

    Article  Google Scholar 

Download references

Acknowledgements

The authors would like to acknowledge the support of the Wisconsin Institute for Discovery, the China Scholarship Council, and the financial support of the National Nature Science Foundation of China (Nos. 51073061, 21174044), the Guangdong Nature Science Foundation (No. S2013020013855), the Fundamental Research Funds for Central Universities (No. 2011ZZ0011), and the 973 Program (2012CB025902) in China.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Lih-Sheng Turng.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Mi, HY., Jing, X., Salick, M.R. et al. Morphology, mechanical properties, and mineralization of rigid thermoplastic polyurethane/hydroxyapatite scaffolds for bone tissue applications: effects of fabrication approaches and hydroxyapatite size. J Mater Sci 49, 2324–2337 (2014). https://doi.org/10.1007/s10853-013-7931-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10853-013-7931-3

Keywords

  • Apatite
  • Simulated Body Fluid
  • Hard Segment
  • Composite Scaffold
  • Liquid Phase Separation