Porous surface modified bioactive bone cement for enhanced bone bonding.
BACKGROUND
Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth.


METHODS
The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant-bone interface was also investigated by push-out tests.


RESULTS
The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect.


CONCLUSIONS
Our findings suggested a new bioactive bone cement for prosthetic fixation in total joint replacement.
Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
Qiang
Q
He
Huiling
H
Chen
Li
L
Huang
Jingjing
J
Dong
Dagang
D
Guo
Mengmeng
M
Mao
Liang
L
Kong
Yang
Y
Li
Zixiang
Z
Wu
Wei
W
Lei
D016475:3T3 Cells; D000464:Alginates / Q000737:chemistry; D000818:Animals; D001843:Bone Cements; D001862:Bone Resorption; D001842:Bone and Bones / Q000378:metabolism; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry; D002448:Cell Adhesion; D002454:Cell Differentiation; D049109:Cell Proliferation; D019245:Compressive Strength; D005260:Female; D005780:Gelatin / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008422:Materials Testing; D051379:Mice; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010006:Osteoblasts / Q000166:cytology; D019904:Polymethyl Methacrylate / Q000737:chemistry; D016062:Porosity; D011817:Rabbits; D013314:Stress, Mechanical; D013499:Surface Properties
D000464:Alginates; D001843:Bone Cements; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D005780:Gelatin; D019904:Polymethyl Methacrylate; D002266:Carboxymethylcellulose Sodium