Anitha A, Joseph John, Menon Deepthy, Nair Shantikumar V, Nair Manitha B
Center for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences & Research Center , Amrita Vishwa Vidyapeetham University, Cochin, India .
Tissue Eng Part A. 2017 Apr;23(7-8):345-358. doi: 10.1089/ten.TEA.2016.0337. Epub 2017 Feb 22.
Nanohydroxyapatite (nanoHA) is a well-established synthetic bone substitute with excellent osteoconduction and osteointegration. However, brittleness coupled with slow degradation curtails its load-bearing and bone regeneration potential, respectively. To address these limitations, nanoHA composite matrix reinforced with electrospun fibrous yarns was fabricated and tested in vitro and in vivo. Different weight percentages (5, 10, 15 wt%) and varying lengths (short and continuous) of poly(l-lactic acid) yarns were randomly dispersed in a gelatinous matrix containing nanoHA. This significantly improved the compressive strength as well as work of fracture, especially for continuous yarns at high weight percentages (10 and 15 wt%). Incorporation of yarns did not adversely affect the pore size (50-350 μm) or porosity of the scaffolds as well as the in vitro cellular response. Finally, when tested in a critical-sized femoral segmental defect in rat, the nanocomposite scaffolds induced osteoblast cell infiltration at 2 months that subsequently underwent increased mature lamellar bone formation at 4 months, in both the mid and peripheral defect regions. Histomorphometric analysis demonstrated that new bone formation and biomaterial degradation were significantly enhanced in the composite scaffold when compared to commercially available HA. Overall, the composite matrix reinforced with electrospun yarns proved to be a potential bone substitute having an appropriate balance between mechanical strength, porosity, biodegradation, and bone regeneration ability.
纳米羟基磷灰石（nanoHA）是一种成熟的合成骨替代物，具有优异的骨传导性和骨整合性。然而，脆性以及缓慢的降解分别限制了其承重和骨再生潜力。为了解决这些局限性，制备了用静电纺丝纤维纱增强的nanoHA复合基质，并进行了体外和体内测试。不同重量百分比（5%、10%、15%）和不同长度（短和连续）的聚（L-乳酸）纱随机分散在含有nanoHA的凝胶状基质中。这显著提高了抗压强度以及断裂功，特别是对于高重量百分比（10%和15%）的连续纱。纱线的加入并未对支架的孔径（50-350μm）或孔隙率以及体外细胞反应产生不利影响。最后，当在大鼠临界尺寸的股骨节段性缺损中进行测试时，纳米复合支架在2个月时诱导成骨细胞浸润，随后在4个月时在缺损的中部和周边区域成熟板层骨形成增加。组织形态计量学分析表明，与市售HA相比，复合支架中的新骨形成和生物材料降解显著增强。总体而言，用静电纺丝纱增强的复合基质被证明是一种潜在的骨替代物，在机械强度、孔隙率、生物降解和骨再生能力之间具有适当的平衡。
