Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
ACS Biomater Sci Eng. 2020 Jul 13;6(7):4024-4035. doi: 10.1021/acsbiomaterials.0c00305. Epub 2020 Jun 23.
Antibiotic-laden poly(methyl methacrylate) (PMMA) bone cement is used in a variety of applications including temporary spacers for load-bearing arthroplasties and non-load bearing orthopedic revision procedures and antibiotic beads to treat infections. Depending upon the surgical preparation technique, properties of PMMA can widely vary. The primary objective of this work was to perform an in-depth structure-function analysis regarding how processing of PMMA impacted material and structural properties (i.e., porosity) and downstream functional properties (i.e., drug refilling and strength). PMMA with cyclodextrin (CD) microparticles was generated via hand- or vacuum-mixing and characterized for material and structural properties including porosity and internal morphology and functional properties of drug refilling, compressive strength, and antimicrobial activity. CD microparticles were incorporated into PMMA to enable functional refilling properties and to determine new information on drug distribution and distance or depth of PMMA which the refilled drug was able to penetrate. Vacuum-mixing of PMMA resulted in improved mechanical strength and allowed for incorporation of greater amounts of CD microparticles but less homogeneity relative to hand-mixing. Refilling studies showed shallow penetration of the drug into PMMA samples without CD. However, PMMA with CD microparticles showed increased depth of drug penetration, indicating that the drug could be delivered deeper within the device, resulting in more drug being available for delivery and more opportunity for later antibiotic refilling on a patient-specific basis. Knowledge of structure-function relationships can assist and provide valuable information in design and optimization of PMMA-CD for specific load-bearing or non-load-bearing applications.
载抗生素聚甲基丙烯酸甲酯（PMMA）骨水泥用于多种应用，包括承重关节置换术的临时间隔物和非承重矫形翻修手术，以及抗生素珠用于治疗感染。根据手术准备技术的不同，PMMA 的性能可能会有很大差异。这项工作的主要目的是深入分析 PMMA 的加工方式如何影响材料和结构特性（即孔隙率）以及下游功能特性（即药物再填充和强度）。通过手动或真空混合生成载有环糊精（CD）微粒的 PMMA，并对其材料和结构特性进行了表征，包括孔隙率和内部形态以及药物再填充、抗压强度和抗菌活性等功能特性。将 CD 微粒掺入 PMMA 中，以实现功能再填充特性，并确定药物分布以及 PMMA 的距离或深度的新信息，再填充药物能够穿透到 PMMA 的这些位置。与手动混合相比，真空混合 PMMA 可提高机械强度并允许掺入更多数量的 CD 微粒，但均匀性较差。再填充研究表明，药物在没有 CD 的情况下仅浅层渗透到 PMMA 样品中。然而，载有 CD 微粒的 PMMA 显示出药物渗透深度增加，表明药物可以在器械内更深的部位输送，从而使更多的药物可用于输送，并为以后根据患者具体情况进行抗生素再填充提供更多机会。结构-功能关系的知识可以在针对特定承重或非承重应用的 PMMA-CD 的设计和优化中提供帮助和有价值的信息。
