Novel cellulose/hydroxyapatite scaffolds for bone tissue regeneration: In vitro and in vivo study
Novel cellulose/hydroxyapatite scaffolds for bone tissue regeneration: In vitro and in vivo study
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DOI：
10.1002/term.2651
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发表时间：
2018-05-01
影响因子：
3.3
通讯作者：
Gomes, Pedro Sousa
中科院分区：
文献类型：
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作者：
Daugela, Povilas;Pranskunas, Mindaugas;Gomes, Pedro Sousa
通过乙酰化衍生物再生纤维素，将无机颗粒机械固定化，然后冷冻干燥，制备了含有纳米或微米羟基磷灰石(nHA或muHA)的纤维素支架。显微断层扫描显示两种支架均呈现高度连通的多孔结构，纤维素/纳米羟基磷灰石的平均孔径为490+/-94微米，纤维素/纳米羟基磷灰石的平均孔径为540+/-132微米。对所开发的支架进行了体外和体内表征。使用商用同种异体骨作为对照材料。为了进行体外鉴定，使用了成骨细胞培养，并随时间进行鉴定，以评估细胞黏附、代谢活性和功能输出(碱性磷酸酶活性和成骨基因表达)。结果显示，与纤维素组和对照组相比，纤维素组与纤维素组和对照组相比，随着纤维素组和对照组丝状孢子数目的增加、MTT值的增加以及成骨基因(RUNX-2、碱性磷酸酶和BMP-2)的表达显著增加，铺展细胞的分布也更广。在兔颅骨缺损模型上对其体内生物相容性进行评价。将所研究的支架植入兔颅骨圆形缺损处。用显微计算机断层扫描和组织学分析对4周和12周的骨活检进行研究。虽然两种纤维素/羟基磷灰石支架的性能都优于所测试的对照组，但在负载纤维素/纳米羟基磷灰石的缺损处发现新形成的矿化组织数量明显更多。在这项研究的限制范围内，开发的纤维素/HA支架在骨再生应用方面显示出良好的结果。对支架的生物反应似乎在很大程度上依赖于HA颗粒的特性，负载有纳米羟基磷灰石的纤维素支架可以引发增强的骨反应。
Cellulose scaffolds containing nano- or micro-hydroxyapatite (nHA or mu HA) were prepared by the regeneration of cellulose from its acetylated derivative and the mechanical immobilization of inorganic particles, followed by freeze-drying. Microtomographic (micro-computed tomography) evaluation revealed that both scaffolds presented a highly interconnected porous structure, with a mean pore diameter of 490 +/- 94 and 540 +/- 132 mu m for cellulose/nHA and cellulose/mu HA, respectively. In vitro and in vivo characterizations of the developed scaffolds were investigated. Commercially available bone allograft was used as a control material. For the in vitro characterization, osteoblastic cell cultures were used and characterized over time to evaluate cell adhesion, metabolic activity, and functional output (alkaline phosphatase activity and osteoblastic gene expression). The results revealed greater spreading cell distribution alongside an increased number of filopodia, higher MTT values, and significantly increased expression of osteoblastic genes (Runx-2, alkaline phosphatase, and BMP-2) for cellulose/nHA, compared with cellulose/HA and the control. The in vivo biocompatibility was evaluated in a rabbit calvarial defect model. The investigated scaffolds were implanted in circular rabbit calvaria defects. Four- and 12-week bone biopsies were investigated using micro-computed tomography and histological analysis. Although both cellulose/HA scaffolds outperformed the assayed control, a significantly higher amount of newly formed mineralized tissue was found within the defects loaded with cellulose/nHA. Within the limitations of this study, the developed cellulose/HA scaffolds showed promising results for bone regeneration applications. The biological response to the scaffold seems to be greatly dependent on the HA particles' characteristics, with cellulose scaffolds loaded with nHA eliciting an enhanced bone response.