Bone in Growth in bFGF Versus BMP Combined with bFGF Saturated PLA-PEG-PLA: Experiment in Surgically Created Rabbit Mandibular Defects

Abstract

A triblock polymer of LPLA and PEG 1000 and 3400 at 3% and 9% was formed by ring opening under nitrogen atmosphere at 120°C and then, in one group, bFGF was added, while in the other both bFGF and BMP were added, leaving one group as a control. Gross, radiographic, histological and scanning electronic microscope observations were done. With the help of motic images advanced 3.0 new bone formed, calculated as a percentage of total selected area and, using SAS6.12, results were analyzed. Statistical analysis between groups showed that, at 2 weeks, the PLA-PEG-PLA + bFGF + BMP group had the highest amount of new bone formation, as a percentage of new bone over total surface area, at 48% followed by the PLA-PEG-PLA + bFGF group at 39%, then the PLA-PEG-PLA=BMP group at 29%. The PLA-PEGPLA group trailed in at 18% (statistical significance, p <0.05=0.0001). After 4 weeks, the experimental groups B and D had almost equal new bone formation (62% and 64% respectively), but still significantly different from the control group and BMP2 group, with 43% and 38% respectively (p <0.05=0.0001). After 8 weeks, there was no difference in the amount of bone regeneration (p >0.05=0.87).

Within the groups, the control group exhibited steady incremental new bone formation at 2, 4 and 8 weeks, starting out at 18%, followed by 42% and lastly 65%. Interestingly this phenomenon also applied to group C (BMP2 group) but not to the B group (bFGF group). The differences at the respective consecutive time of examination were statistically significant (p <0.05=0.0001). However, in both experimental groups B and D there was statistically significant difference between new bone formed at 2 weeks compared to that at 4 weeks, but thereafter the increment was negligible.

Keywords

tissue engineering bFGF BMP PLA-PEG-PLA synthetic biomaterials growth factors bone tissue

Get full access to this article

View all access options for this article.

References

Lane, J.M. , Yasko, A.W. , Tomin, E. , Cole, B.J. , Waller, S. , Browne, M. , Turek, T. and Gross, J. (1999). Bone Marrow and Recombinant Human, Morphogenic Protein-2 in Osseous Repair , Clin. Orthop., 361: 216-227 .

Hu, R.W. , Bohlman, H.H. (1994). Fracture at the Iliac Bone Graft Harvest Site After Infusion of the Pine , Clin. Orthop., 301: 208-213 .

Concannon, M.J. , Boschert, M.T. , Puckett, C.L. (1997). Bone Induction Using Demineralised Bone in Rabbit Femur. A Long Term Study , Plast Reconstr Surg., 99(7): 1983-1988 .

Ma, P.X. , Choi, J.W. (2001). Biodegradable Polymer Scaffolds with Well-defined Interconnected Spherical Pore Network . Tissue Eng., 7(1) 23-33 .

Middleton, J.C. and Tipton, A.J. (1998). Synthetic Biodegradable Polymer as Medical Devices. Medical Plastics and Biomaterials. Online, available at: www.devicelink.com/mph/archive/98/03/002.html

Yetkin, H. , Senkoylu, A. , Cila, E. , Muhtar A.O. and Simsek, A. (2000). Biodegradable Implants in Orthopaedics and Traumatology, Turk. J . Med. Sci., 30: 297-301 .

Coutts, R.D. , Healey, R.M. , Ostrander, R. , Sah, R.C. , Goomer, R. and Amiel, D. (2001). Matrices for Cartilage Repair . Clin. Orthop. Relat. Res., 391: s271-s275 .

Andreas, W. , Reinhard, F.G.H. , Andreas, C.S. , Hanns-Joachim, H. and Norbert P.S. (2000). Current Concepts Biodegradable Implants in Sports Medicine: the Biological Base , The Journal of Arthroscopic and Related Surgery, 16(3): 305-321 .

Groger, A. , Klaring, S. , Merten, H.A. , Holste, J. , Kaps, C. and Sittinger, M. (2003). Tissue Engineering of Bone for Mandibular Audmentation in Immunocompetent Minipigs: Preliminary Study . Scand. J. Plast. Reconstr. Surg. Hand Surg., 37: 129-133 .

10.

Salgado, A.J. , Coutinho, O.P. and Reis, R.L. (2004) Bone Tissue Engineering. State of the Art and Future Trends , Macromol. Biosci., 4: 743-765 .

11.

Hu, Y. , Rogunova, M. , Topolkaraev, V. , Hiltner, A. and Baer, E. (2003). Aging of Poly(lactide)/Poly(ethylene glycol) Blends. Part 1. Poly(lactide) with Low Stereoregularity , Polymer, 44: 5701-5710 .

12.

Saito, N. , Okada, T. , Horiuchi, H. , Murakami, N. , Takahashi, J. , Nawata, M. , et al. (2001). Biodegradable Poly-D, L-lactic Acid-Polyethylene Glycol Block Copolymers as a BMP Delivery System for Inducing Bone , J. Bone Joint Surg. Am., 83-A Suppl 1(Pt 2): S92-S98 .

13.

Murakami, N. , Saito, N. , Horiuchi, H. , Okada, T. , Nozaki, K. , Takaoka, K. (2002). Repair of Segmental Defects in Rabbit Humeri with Titanium Fiber Mesh Cylinders Containing Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2) and a Synthetic Polymer . J. Biomed. Mater. Res., 62(2): 169-174 .

14.

Dong Woo Lim and Tae Gwan Park . (2000). Stereo Complex Formation Between Enantiomeric PLA-PEG-PLA Triblock Copolymer: Characterisation and Use as Protein-Delivery Micro Particulate Carriers , Appl. Polym. Sci., 75: 1615-1623 .

15.

Malafaya, P.B. , Silva, G.A. , Baran, E.T. and Reis, R.L. (2002). Drug Delivery Therapies II. Strategies for Delivering Bone Regenerating Factors . Curr. Opin. Solid state matter Sci., 6: 297-312 .

16.

Sholar, A. and Stadelmman, W. Wound Healing Chronic Wounds. Online, available at: www.emedicine.com/plastic/topic477.htm.

17.

Takeuchi, R. (2004). The Effect of Basic Fibroblast Growth Factor on Cell Cycle in Human Gingival Fibroblasts from Nifedipine Responder and Non-responder , J. Oral Sci., 46(1): 37-44 .

18.

Liang, H. , Pun, S. and Wronski, T. (1999). Bone Anabolic Effects of Basic Fibroblast Growth Factor in Ovariectomized Rats . Endocrinology, 140(12): 5780-5788 .

19.

Setti S. Rengachary . (2002). BMP: basic concepts , Neurosurg. Focus, 6(13): 1-6 .

20.

Groeneveld, E.H.J. and Burges, E.H. (2000). BMP in Human Bone Regeneration , Eur. J. Endocrinol., 142: 9-21 .

21.

Simmons, C.A. , Alsberg, E. , Hsiong, S. , Kim, J.W. and Mooney, D.J. (2004). Dual Growth Factor Delivery and Controlled Scaffold Degradation Enhance In Vivo Bone Formation by Transplanted Bone Marrow Stromal Cells , Bone, 35: 562-569 .

22.

Ripamonti, U. , Crooks, J. , Petit, J.C. , Rueger, D.C. (2001). Periodontal Tissue Regeneration by Combined Applications of Recombinant Human Osteogenic Protein-1 and Bone Morphogenetic Protein-2. A Pilot Study in Chacma Baboons (Papio ursinus) , Eur. J. Oral Sci., 109(4): 241-248 .

23.

Ziegler, J. , Mayr-Wohlfart, S. , Kessler, BD ., Gunther, K.-P. (2002). Adsorption and Release Properties of Growth Factors from Biodegradable Implants. J. Biomed. Mater. Res., 59: 422-428 .

24.

Noel, D. , Gazit, D. , Bouquet, C. , Apparailly, F. , Bony, C. , Plence, P. et al. (2004). Short-Term BMP-2 Expression is Sufficient for In Vivo Osteochondral Differentiation of Mesenchymal Stem Cells , Stem Cells, 22(1): 74-85 .

25.

Stevens, M.M. , Marini, R.P. , Martin, I. , Langer, R. , Shastri, P.V. (2004). FGF-2 Enhances TGFβ-1-induced Periosteal Chondrogenesis , J. Orthop. Res., 22: 1114-1119 .

26.

Coelho, P. Leitao, J. Santos, C. , Mascarenhas, R. et al. Transforming Growth Factor beta-3 (TGFβ3) Activity is Relatively Dependent on Carriers’ Differences When Used for a Critical Mandibular Bone Defect Repair in a Beagle dog model , Eur. Cell Mater., 7(suppl. 1): 50

27.

Yunyu Hu , Chao Zhang , Shuming Zhang , Zhuo Xiong , Jianqiang Xu . (2003). Development of Porous Poly(L-lactic acid)/Hydroxyapatite/Collagen Scaffold as a BMP Delivery System and its Use in Healing Canine Segmental Bone Defect , J. Biomed. Mater. Res., 1(67A(2)): 591-598 .

28.

Golembo, M. , Azachi, M. , Gladnikoff, M. , Barkay, H. and Yayon, A. (2003). Controlled Release of Novel FGF Variants for Bone Fracture Healing . Eur. Cell Mater. 5(suppl 2): 64-65 .

29.

Schnettler, R. , Alt, V. , Dingeldein, E. , Pfefferle, H.J. , Kilian, O. , Meyer, C. , Heiss, C. and Wenisch, S. (2003). Bone Ingrowth in bFGF-coated Hydroxyapatite Ceramic Implants , Biomaterials, 24(25): 4603-4608 .