| Background: Clinically, bone atrophy, absorption, defect on jaw or skullowing to congenital defect, tumor, external injury, periodontitis and so on, notonly affect acromegalic mastication, pronunciation and beautiful outlook, butalso have an influence in psychology. Now the methods of treating bone defecthave a restrictive application because of each merit and demerit. It is difficult tocure the defects of bone only by depending on their own ability of regeneration.In recent years, the rapid development of bone tissue engineering has broughtnew ideas for bone regeneration. Investigation of scaffolds which load boneformation promoting factors has become a hot topic as a branch of the bonetissue engineering.Objectives: We fabricate and characterize PLGA/HA nano-fibrecomposite scaffolds containing pBMP-2/PEI, evaluate the biocompatibility ofnanofiber scaffolds, and examine the effect of the nanofiber scaffolds on boneregeneration in rats calvarial defects.Methods: We fabricated PLGA nano-fibre scaffolds， PLGA/HAnano-fibre composite scaffolds and PLGA/HA nano-fibre composite scaffoldscontaining pBMP-2/PEI by electrospinning, and characterized them throughSEM. In vitro，we evaluated the biocompatibility of nanofiber scaffolds bycell attachment and MTT experiments.Mice pre-osteoblast(MC3T3-E1) wasused. In vivo, we examined the effect of the nanofiber scaffolds on boneregeneration in rats calvarial defects. Twenty-four female Wistar rats wererandomly divided into three groups:control group, PLGA/HA scaffold groupand PLGA/HA/pBMP-2/PEI scaffold group. A circular critical-sized (Dia= 5mm) defect was prepared on Calvaria Herringbone seam bone of all rats.Cardiac perfusions by physiological saline and4%paraformaldehyde wereexecuted at four and eight weeks after implantations. Specimens of each groupwere harvested and fixed in4%paraformaldehyde for24hours, and then beenanalysised by Micro-CT and histological analysis.Results：We have successfully constructed of PLGA nano-fibre scaffolds，PLGA/HA nano-fibre composite scaffolds and PLGA/HA nano-fibre compositescaffolds containing pBMP-2/PEI. The SEM images showed the diameters ofthe fibers ranged from100nm~2μm. These fibers arranged irregularly in whichthere were many mesh space. Cell attachment experiments showed that cellcould have a good attachment on scaffolds and have a good condition. Withtime prolonging the cell number have a growing trend. MTT experimentsshowed that the absorbance value of PLGA scaffolds group andPLGA/HA/pBMP-2/PEI scaffolds group had a significant growing at1,3,5days(P＜0.05). And the absorbance value of PLGA/HA scaffolds group had asignificant growing at1,5days(P＜0.05). The growth of absorbance valuesuggested that cell number of the three scaffolds have a significant growingwith time prolonging. Transverse on the contrast, there were no significantdifference among the absorbance value of PLGA scaffolds group, PLGA/HAscaffolds group and PLGA/HA/pBMP-2/PEI scaffolds group at1,3days(P>0.05). It suggested that there were no significant difference among thenumber of cells in these three groups at the same time point(1,3days). Therewere no significant difference between the absorbance value of PLGA scaffoldsgroup and PLGA/HA/pBMP-2/PEI scaffolds group at5days(P>0.05). Itsuggested that there were no significant difference between the number of cellsin the two groups. In vivo, the results of Micro-CT and histological analysisshowed, at the time of four and eight weeks, control group and PLGA/HAscaffolds group had almost no new bone formation. In contrast, PLGA/HA/ pBMP-2/PEI scaffolds group had a significant new bone formation. Itsuggested that PLGA/HA/pBMP-2/PEI nano-fibre composite scaffolds had abetter promoting role on bone regeneration in rats calvarial defects comparedwith the control group.Conclusions： PLGA/HA Nano-fibre composite scaffolds containingpBMP-2/PEI had good biocompatibility and little toxicity. The results indicatedthat PLGA/HA/pBMP-2/PEI nano-fibre scaffolds might have potentialapplications in the tissue engineering field. |
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