The Capes Foundation, Ministry of Education of Brazil, Cx. Postal 365, Brasília DF 70359-970, Brazil.
J Biomater Appl. 2012 Aug;27(2):187-200. doi: 10.1177/0885328211398968. Epub 2011 May 17.
Treatment with antibiotics within the periodontal pocket against bacterial infections represents a useful and adjunctive tool to conventional therapy for healing and teeth preservation. With this function in view, an implantable, tetracycline delivery device for the treatment of periodontal disease was developed. The aim of this study was to develop biodegradable, tetracycline-loaded microparticles made of two polymers: PLGA and zein which were compressed into monolithic devices. In this polymer delivery system, the encapsulation efficiency, release characteristics, drug-polymer interaction, and antibacterial activity of loaded drug were investigated. The interaction of tetracycline with the corn protein zein was studied by nuclear magnetic resonance (NMR), Fourier transform infrared, and X-ray diffraction. The hydrophobic interaction of tetracycline with zein in the formulations was deduced from the NMR studies, whereas X-ray diffraction studies showed a new crystalline state of the drug in the presence of the protein. Zein was not denatured by preparation of inserts. Sustained release of tetracycline was obtained, and the proportion of zein in the inserts had a great impact on the drug release. Finally, an effective tetracycline release from inserts against Staphylococcus aureus was achieved over 30 days. In conclusion, the PLGA:zein delivery system described in this study was found to be effective in controlled delivery of tetracycline, and hence may be suitable for intra-pocket delivery of antimicrobial agents in the treatment of periodontitis.
用抗生素治疗牙周袋内的细菌感染是一种针对常规治疗的有益且辅助性的方法，可用于治疗和保存牙齿。有鉴于此，开发了一种可植入的、载有四环素的牙周病治疗给药装置。本研究的目的是开发可生物降解的、载有四环素的微球，这些微球由两种聚合物：PLGA 和玉米蛋白组成，并被压缩成整体装置。在这种聚合物给药系统中，研究了包封效率、释放特性、药物-聚合物相互作用和载药的抗菌活性。通过核磁共振（NMR）、傅里叶变换红外和 X 射线衍射研究了四环素与玉米蛋白玉米朊的相互作用。从 NMR 研究中推断出四环素与制剂中玉米朊的疏水相互作用，而 X 射线衍射研究表明，在存在蛋白质的情况下，药物呈现出新的结晶状态。玉米朊在制备插塞时没有变性。载有四环素的微球实现了持续释放，并且插塞中玉米朊的比例对药物释放有很大影响。最后，在 30 天的时间内，从插塞中实现了对金黄色葡萄球菌的有效四环素释放。总之，本研究中描述的 PLGA：玉米朊给药系统被发现可有效控制四环素的释放，因此可能适用于牙周炎的袋内局部抗菌药物输送。
