Enhanced cell ingrowth and proliferation through three-dimensional nanocomposite scaffolds with controlled pore structures.

We present enhanced cell ingrowth and proliferation through cross-linked three-dimensional (3D) nanocomposite scaffolds fabricated using poly(propylene fumarate) (PPF) and hydroxyapatite (HA) nanoparticles. Scaffolds with controlled internal pore structures were produced from computer-aided design (CAD) models and solid freeform fabrication (SFF) technique, while those with random pore structures were fabricated by a NaCl leaching technique for comparison. The morphology and mechanical properties of scaffolds were characterized using scanning electron microscopy (SEM) and mechanical testing, respectively. Pore interconnectivity of scaffolds was assessed using X-ray microcomputed tomography (micro-CT) and 3D imaging analysis. In vitro cell studies have been performed using MC3T3-E1 mouse preosteoblasts and cultured scaffolds in a rotating-wall-vessel bioreactor for 4 and 7 days to assess cell attachment, viability, ingrowth depth, and proliferation. The mechanical properties of cross-linked nanocomposite scaffolds were not significantly different after adding HA or varying pore structures. However, pore interconnectivity of PPF/HA nanocomposite scaffolds with controlled pore structures has been significantly increased, resulting in enhanced cell ingrowth depth 7 days after cell seeding. Cell attachment and proliferation are also higher in PPF/HA nanocomposite scaffolds. These results suggest that cross-linked PPF/HA nanocomposite scaffolds with controlled pore structures may lead to promising bone tissue engineering scaffolds with excellent cell proliferation and ingrowth.

[1]  Antonios G Mikos,et al.  Formation of three-dimensional cell/polymer constructs for bone tissue engineering in a spinner flask and a rotating wall vessel bioreactor. , 2002, Journal of biomedical materials research.

[2]  Lichun Lu,et al.  The roles of matrix polymer crystallinity and hydroxyapatite nanoparticles in modulating material properties of photo-crosslinked composites and bone marrow stromal cell responses. , 2009, Biomaterials.

[3]  Tadashi Kokubo,et al.  Pore throat size and connectivity determine bone and tissue ingrowth into porous implants: three-dimensional micro-CT based structural analyses of porous bioactive titanium implants. , 2006, Biomaterials.

[4]  Byung-Soo Kim,et al.  A poly(lactide-co-glycolide)/hydroxyapatite composite scaffold with enhanced osteoconductivity. , 2007, Journal of biomedical materials research. Part A.

[5]  K. Hong,et al.  Osteoconduction at porous hydroxyapatite with various pore configurations. , 2000, Biomaterials.

[6]  Lichun Lu,et al.  Bone-tissue-engineering material poly(propylene fumarate): correlation between molecular weight, chain dimensions, and physical properties. , 2006, Biomacromolecules.

[7]  Benjamin M. Wu,et al.  In vitro response of MC3T3-E1 pre-osteoblasts within three-dimensional apatite-coated PLGA scaffolds. , 2005, Journal of biomedical materials research. Part B, Applied biomaterials.

[8]  Shanfeng Wang,et al.  Physical properties and cellular responses to crosslinkable poly(propylene fumarate)/hydroxyapatite nanocomposites. , 2008, Biomaterials.

[9]  D. Hutmacher,et al.  Scaffolds in tissue engineering bone and cartilage. , 2000, Biomaterials.

[10]  Rongfang Liu,et al.  Preparation and characterization of nano-hydroxyapatite/polymer composite scaffolds , 2008, Journal of materials science. Materials in medicine.

[11]  Esmaiel Jabbari,et al.  Fabrication and characterization of poly(propylene fumarate) scaffolds with controlled pore structures using 3-dimensional printing and injection molding. , 2006, Tissue engineering.

[12]  S J Hollister,et al.  Manufacturing and Characterization of 3‐D Hydroxyapatite Bone Tissue Engineering Scaffolds , 2002, Annals of the New York Academy of Sciences.

[13]  S F Hulbert,et al.  Potential of ceramic materials as permanently implantable skeletal prostheses. , 1970, Journal of biomedical materials research.

[14]  Dietmar W Hutmacher,et al.  Assessment of bone ingrowth into porous biomaterials using MICRO-CT. , 2007, Biomaterials.

[15]  S. Hollister.  Porous scaffold design for tissue engineering , 2005, Nature materials.

[16]  K. Burg,et al.  Biomaterial developments for bone tissue engineering. , 2000, Biomaterials.

[17]  J O Hollinger,et al.  Biodegradable bone repair materials. Synthetic polymers and ceramics. , 1986, Clinical orthopaedics and related research.

[18]  D. Kaplan,et al.  Porosity of 3D biomaterial scaffolds and osteogenesis. , 2005, Biomaterials.

[19]  A. Mikos,et al.  Crosslinking characteristics of an injectable poly(propylene fumarate)/β‐tricalcium phosphate paste and mechanical properties of the crosslinked composite for use as a biodegradable bone cement , 1999 .

[20]  Ralph Müller,et al.  Nondestructive micro-computed tomography for biological imaging and quantification of scaffold-bone interaction in vivo. , 2007, Biomaterials.

[21]  A. Mikos,et al.  Marrow stromal osteoblast function on a poly(propylene fumarate)/beta-tricalcium phosphate biodegradable orthopaedic composite. , 2000, Biomaterials.

[22]  K. Shakesheff,et al.  In vitro assessment of cell penetration into porous hydroxyapatite scaffolds with a central aligned channel. , 2004, Biomaterials.

[23]  F. E. Wiria,et al.  Poly-ε-caprolactone/hydroxyapatite for tissue engineering scaffold fabrication via selective laser sintering , 2007 .

[24]  Seeram Ramakrishna,et al.  Development of nanocomposites for bone grafting , 2005 .

[25]  Esmaiel Jabbari,et al.  Quantitative analysis of interconnectivity of porous biodegradable scaffolds with micro-computed tomography. , 2004, Journal of biomedical materials research. Part A.

[26]  Suprakas Sinha Ray,et al.  Polylactide based nanostructured biomaterials and their applications. , 2007, Journal of nanoscience and nanotechnology.

[27]  O. Kwon,et al.  A composite of hydroxyapatite with electrospun biodegradable nanofibers as a tissue engineering material. , 2005, Journal of bioscience and bioengineering.

[28]  Lichun Lu,et al.  A Biodegradable and Cross-Linkable Multiblock Copolymer Consisting of Poly(propylene fumarate) and Poly(ε-caprolactone): Synthesis, Characterization, and Physical Properties , 2005 .

[29]  W. Jie,et al.  Tissue engineering scaffold material of nano-apatite crystals and polyamide composite , 2004 .

[30]  M J Yaszemski,et al.  Three-dimensional culture of rat calvarial osteoblasts in porous biodegradable polymers. , 1998, Biomaterials.

[31]  S. Goldstein,et al.  The direct examination of three‐dimensional bone architecture in vitro by computed tomography , 1989, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[32]  C. Lohmann,et al.  Migration, Matrix Production and Lamellar Bone Formation of Human Osteoblast-Like Cells in Porous Titanium Implants , 2002, Cells Tissues Organs.

[33]  Peter X Ma,et al.  Structure and properties of nano-hydroxyapatite/polymer composite scaffolds for bone tissue engineering. , 2004, Biomaterials.

[34]  E. D. Rekow,et al.  MicroCT analysis of hydroxyapatite bone repair scaffolds created via three-dimensional printing for evaluating the effects of scaffold architecture on bone ingrowth. , 2008, Journal of biomedical materials research. Part A.

[35]  L. Yahia,et al.  Biocompatibility of novel polymer-apatite nanocomposite fibers. , 2008, Journal of biomedical materials research. Part A.