Cornelia Cretiu Vasiliu Fundamentals of Nanotechnology

M otivation M ethods of synthesis C haracterization of structure M orphology and particle size distribution P roperties & A pplications 2

 Bone: 2 nd most implanted tissue after blood  Protein matrix containing type 1 collagen and minerals  Calcium as: (Ca 2+ ) 10-x (H 3 O + ) 2x *(PO 4 ) 6 (OH - ) 2  Synthetic vs. homo-, allo-, xeno-geneic implants  Properties: biocompatibility, biodegradability, mechanical integrity, vascularization inductivity, osteoconductivity, and osteoinductivity 3

Methods of synthesis Methods of synthesis HA Wet methods 5 Solid-state reactions 6 Sol-gel 7 Ellectrocrystallization 8 Spray pyrolysis 9 Emulsion processing 10 Hydrothermal treatment 11 nHA Chemical precipitation 1 Hydrothermal treatment 12 Microwave synthesis 2 To be considered: stoichiometry, pH, rate of addition, ionic strength 4

Co precipitation 1) Ca(OH) 2 + H 3 PO 4 n HA Aqueous, pH 8, 38 o C Microwave synthesis 2) 10 Ca(OH) 2 +6 (NH 4 )2HPO 4 Ca 10 (PO 4 ) 6 (OH) 2 +6H 2 O+12NH 4 OH 850W, 20 min. 13) Aq. Sol. NaNO 3, Ca(NO 3 ) 2 ·4H 2 O and KH 2 PO 4 precursor 600W, 5 min. stirred in H 2 O ( room temperature, 1 h) nHA particles. nHA Methods of synthesis 5

 XRD( 1 Powder XRD of the HA precipitate: (a) as-prepared, (b) calcined at 700 °C, (c) calcined at 800 °C, (d) calcined at 900 °C and (e) calcined at 1200 °C. [specific peaks :(H) HAP; (b) β-TCP; (a) α-TCP].( 1 6

IR( 1 spectra of the nHA precipitates:  (a) as-dried,  (b) calcined at 700 °C,  (c) calcined at 800 °C,  (d) calcined at 900 °C and  (e) calcined at 1200 °C. 7

8 TEM micrograph of as-synthesized nano HA crystals( 14 SEM micrograph of the as-prepared nHA( 1

9  DLS: Histogram representation of the mean diameters of as- prepared nHA suspended in aqueous solution. ( 1

10 Applications Applications  Cell morphology after being cultured for 15 min on the different nHA coated(G2) and uncoated(G1H) titanium surfaces.  Surface roughness decreased ( 2  nHA doped PLGA composite (30% nHA) hollow fiber membrane fabricated using wet phase inversion technique ( 13 (2(2 ( 13 Coatings Fibers, tubes

11 Bone filler( 4 (A)Preoperative axial CT (B) Lateral preoperative view (C) After reduction, the remaining defect was filled with nHA paste. (D) Postoperative radiograph (E) 6 weeks after surgery. The patient progressed to full weight bearing at this point in time. (F) 12 months postoperatively, only a marginal loss of correction could be measured.

12 Future developments Future developments CT scan Computer file Choose customized design Print, sinter implant Seed cells, growth factors Implant

1. 1/2/501b2d84c7d81d8e9dc db1 Phase 1/2/501b2d84c7d81d8e9dc db1 2. Xiaolong Zhu et al 2006 Nanotechnology /2/2a01537a8d0b528852bb67f079d7e91a Rapid densification 3/2/2a01537a8d0b528852bb67f079d7e91a 4. F. Huber, J. Hillmeier, N. McArthur, H. Kock and P. J. Meeder, The Use of Nanocrystalline Hydroxyapatite for the Reconstruction of Calcaneal Fractures: Preliminary Results, J. of Foot and Ankle Surgery Vol. 45/ 5, 2006, pp C. Liu, Y. Huang, W. Shen and J. Cui, Biomaterials 22 (2001), pp. 301– X. Yang and Z. Wang, J. Mater. Chem. 8 (1998), pp. 2233– W. Feng, L. Mu-sen, L. Yu-peng and Q. Yong-xin, Mater. Lett. 59 (2005), pp. 916– S.K. Yen and C.M. Lin, Mater. Chem. Phys. 77 (2003), pp. 70– K. Itatani, T. Nishioka, S. Seike, F.S. Howell, A. Kishioka and M. Kinoshita, J. Am. Ceram. Soc. 77 (1994), pp. 801– C.-W. Chen, R.E. Riman, K.S. TenHuisen and K. Brown, J. Cryst. Growth 270 (2004), pp. 615– G.Z. Hui, Z. Qingshan and H.X. Zhao, Mater. Res. Bull. 40 (2005) (8), pp. 1326– W.L. Suchanek, K. Byrappa, P. Shuk, R.E. Riman, V.F. Janas and K.S. TenHuisen, J. Solid State Chem. 177 (2004), pp. 793– N. Zhang et al. / Materials Science and Engineering C 27 (2007) 599– S. Ramesh et al. / Ceramics International 33 (2007) 1363–

14 HA: βTCP 60: o C/4h HA: βTCP 60: o C/4h