Preparation And Mechanical Properties Of Artificial Bone Biomimetic Materials For Treatment Of OVCFs

Objective:The human body structural artificial bone bionic material was designed and prepared,and its mechanical properties were studied.The surgical treatment of spinal compression fractures provided a filling material with similar mechanical properties to human cancellous bone.Methods:Polypropylene fumarate was synthesized by two-step method of diethyl fumarate and 1,2-propanediol.The synthesized PPF was cross-linked with N-VP andβ-TCP,according to PPF andβ-The ratio of TCP quality 10:1,5:1,3:1,2:1 was divided into group 1,group 2,group 3,group 4,and the mechanical properties of the product were tested.Take 4 fresh calf spines,cut the waist 1 to the waist 4 vertebral body,remove the vertebral body attachment,measure the area of the vertebral body by indirect method,select 10 vertebral bodies with similar force areas,and randomly divide into group A(PPF/Theβ-TCP complex group)and the B group(PMMA bone cement group)were tested for the strength and stiffness of the two groups of vertebral bodies before surgery.The calf vertebral bodies were compressed to fractures using the MTS-858biomechanical machine.Group A was treated with PPF cross-linking complex and group B using PMMA bone cement for vertebroplasty.The filling volume of each vertebral body was recorded.The postoperative vertebral body strength and stiffness were compared between the two groups and compared with preoperative mechanical data.Results:The PPF prepared by the two-step method was characterized by gel permeation chromatography and nuclear magnetic resonance spectroscopy to describe the structural characteristics of the product composite target product.The maximum temperature of the four groups in the process of PPF and N-VP,β-TCP cross-linking was 47.6±1.8°C,and the compressive strength and elastic modulus were group 1:(53.52±1.5MPa,0.965±0.04GPa);group 2:(63.15±0.4 MPa,1.050±0.05 GPa);Group 3:(97.88±5.5MPa,1.100±0.10 GPa);Group 4:(100.8±3.2 MPa,0.450±0.18 GPa).Indirect method of calf vertebral body area was calculated:group A(12.2±0.14cm~2);group B(12.06±0.08cm~2),the difference was not statistically significant(P>0.05),suggesting that the two groups of calf vertebral body were affected.The area of force is comparable;the percentage of vertebral height recovery in the two groups:A group(59%±2.75%)and B group(62.4%±1.95%),the difference was not statistically significant(P>0.05),suggesting that group A and There was no significant difference in vertebral height recovery between group B;initial strength and stiffness of calf vertebral body:group A(2282±341N)(215±27N/mm),group B(2350±289N)(221±26N/mm),Postoperative strength and stiffness:Group A:(1848±219 N)(182±15 N/mm),Group B:(3105±452 N)(296±37 N/mm).The data of the two groups were compared.The mechanical performance of group B was stronger than that of group A and stronger than that of preoperative group.The difference was statistically significant(P<0.05),suggesting that the mechanical strength of PMMA bone cement after implantation into vertebral body is greater than that of PPF.The composite is larger than the mechanical strength of the vertebral body itself,and the mechanical strength of the PPF crosslinked composite after injection into the vertebral body is comparable to the mechanical strength of the vertebral body itself.Conclusion:The mechanical strength of PPF cross-linked composites is comparable to the mechanical strength of vertebral bodies.It is a good vertebral body filling material.