Structurally Tuned Antimicrobial Mesoporous Hydroxyapatite Nanorods by Cyclic Oligosaccharides Regulation To Release a Drug for Osteomyelitis

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• 作者：M. Selvakumar ; P. Senthil Kumar ; Bodhisatwa Das ; Santanu Dhara ; Santanu Chattopadhyay
• 刊名：Crystal Growth & Design
• 出版年：2017
• 出版时间：February 1, 2017
• 年：2017
• 卷：17
• 期：2
• 页码：433-445
• 全文大小：982K
• ISSN：1528-7505

文摘

This work unveils a straightforward and controlled biomimetic synthesis (combined modified coprecipitation and sonochemistry method) of rod-like two-dimensional (2D) hydroxyapatite (HA) nanoparticles with an aspect ratio of ∼13.2 and their mesoporous nanorods (small and large pore) by fine regulation of the morphology using a β-cyclodextrin (β-CD) oligomer. Various methodical characterization results such as from wide-angle X-ray diffraction, high-resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller analysis, and Fourier transform infrared spectroscopy comprehensively established that β-CD acts as an effective nucleating agent by virtue of strong adsorption of α-d-glucopyranoside moieties of β-CD on the surface of calcium phosphate as well as owing to electrostatic interactions due to the toroid and cyclic structure of β-CD. Besides, improved crystallinity of HA nanorods, as well as induced crystal growth of nanorods along the [110] crystallographic direction, was observed from the HRTEM micrographs. Consequently, a plausible mechanism also is proposed for the nucleation and growth of the nanorods followed by their crystallization. Subsequently, the prepared tuned mesoporous nanorods were employed as a drug carrier and delivery system using ciprofloxacin (CFX) drug for the treatment of osteomyelitis. Eventually, CFX-encapsulated βCD wrapped mesoporous hydroxyapatite (MPHA) nanocrystals showed a greater drug loading capability (∼79%). They also showed sustained release characteristics (in vitro). Furthermore, antimicrobial activity showed a significant zone of inhibition of ∼33 mm of the CFX-loaded mesoporous frames, especially for the βCD-MPHA nanocrystals. A hemolysis assay with human erythrocytes displayed good blood compatibility (less than ∼1% of hemolysis) of the prepared various HA nanorods. Besides, robust cell proliferation at day 7 as well as zero toxicity level of the prepared different HA nanocrystals was confirmed by MTT assays and monitoring of cell adhesion as well as cell morphology (cytoskeleton) by fluorescence microscopy using osteoblast cells. Thus, these structurally tuned nanocrystals along with combinatorial properties indicate a broad range of potential biomedical applications particularly as a biomaterial for osteomyelitis therapy. Likewise, they can also be used as nanofillers in fabricating a bio-nanocomposite with a suitable matrix for bone tissue engineering, where infection is a major problem of osteoblast proliferation.