Department of Chemical Engineering and Pharmaceutical Technology, Universidad de La Laguna, 38200 La Laguna, Spain.
Department of Biochemistry, Microbiology, Cell Biology and Genetics, Universidad de La Laguna, 38200 La Laguna, Spain; Institute of Biomedical Technologies (ITB), Center for Biomedical Research of the Canary Islands (CIBICAN), Universidad de La Laguna, 38200 La Laguna, Spain.
Mater Sci Eng C Mater Biol Appl. 2020 Oct;115:111009. doi: 10.1016/j.msec.2020.111009. Epub 2020 Apr 23.
In the present study, two different PLGA-Alginate scaffolds, a hydrogel (HY) and a solid sponge (SS), were developed for β-estradiol and BMP-2 sustained delivery for bone regeneration in osteoporosis. β-Estradiol and BMP-2 were encapsulated in PLGA and PLGA-Alginate microspheres respectively. Scaffolds were characterized in vitro in terms of porosity, water uptake, release rate and HY rheological properties. BMP-2 release profiles were also analysed in vivo. The bone regeneration induced by both HY and SS was evaluated using a critical-sized bone defect in an osteoporotic (OP) rat model. Compared to HY, SS presented 30% higher porosity, more than double water absorption capacity and almost negligible mass loss compared to the 40% of HY. Both systems were flexible and fit well the defect shape, however, HY has the advantage of being injectable. Despite both delivery systems had similar composition and release profile, bone repair was around 30% higher with SS than with HY, possibly due to its longer residence time at the defect site. The incorporation of mesenchymal stem cells obtained from OP rats did not result in any improvement or synergistic effect on bone repair.
在本研究中，开发了两种不同的 PLGA-海藻酸钠支架，一种水凝胶（HY）和一种固体海绵（SS），用于β-雌二醇和 BMP-2 的持续释放，以促进骨质疏松症中的骨再生。β-雌二醇和 BMP-2 分别被包封在 PLGA 和 PLGA-海藻酸钠微球中。体外研究了支架的孔隙率、吸水率、释放率和 HY 流变性能。还分析了体内 BMP-2 的释放曲线。使用骨质疏松（OP）大鼠模型中的临界尺寸骨缺损评估了 HY 和 SS 诱导的骨再生。与 HY 相比，SS 的孔隙率高 30%，吸水率是 HY 的两倍多，而质量损失几乎可以忽略不计，仅为 HY 的 40%。两种系统都具有柔韧性，与缺损形状吻合良好，但 HY 具有可注射性的优势。尽管两种给药系统具有相似的组成和释放曲线，但 SS 的骨修复效果比 HY 高约 30%，这可能是由于其在缺损部位的停留时间更长。从 OP 大鼠中获得的间充质干细胞的掺入并没有对骨修复产生任何改善或协同作用。
