Oei James D, Zhao William W, Chu Lianrui, DeSilva Mauris N, Ghimire Abishek, Rawls H Ralph, Whang Kyumin
Department of Comprehensive Dentistry, Division of Research, University of Texas Health Science Center San Antonio, San Antonio, Texas.
J Biomed Mater Res B Appl Biomater. 2012 Feb;100(2):409-15. doi: 10.1002/jbm.b.31963. Epub 2011 Nov 21.
Polymethyl methacrylate (PMMA) is widely used to treat traumatic head injuries (cranioplasty) and orthopedic injuries (bone cement), but there is a problem with implant-centered infections. With organisms such as Acinetobacter baumannii and methicillin-resistant staphylococcus aureus developing resistance to antibiotics, there is a need for novel antimicrobial delivery mechanisms without risk of developing resistant organisms.
To develop a novel antimicrobial implant material by generating silver nanoparticles (AgNP) in situ in PMMA.
All PMMA samples with AgNP's (AgNP-PMMA) released Ag(+) ions in vitro for over 28 days. In vitro antimicrobial assays revealed that these samples (even samples with the slowest release rate) inhibited 99.9% of bacteria against four different strains of bacteria. Long-term antimicrobial assay showed a continued antibacterial effect past 28 days. Some AgNP-loaded PMMA groups had comparable Durometer-D hardness (a measure of degree of cure) and modulus to control PMMA, but all experimental groups had slightly lower ultimate transverse strengths.
AgNP-PMMA demonstrated a tremendously broad-spectrum and long-intermediate-term antimicrobial effect with comparable mechanical properties to control PMMA. Current efforts are focused on further improving mechanical properties by reducing AgNP loading and assessing fatigue properties.
聚甲基丙烯酸甲酯（PMMA）被广泛用于治疗创伤性脑损伤（颅骨成形术）和骨科损伤（骨水泥），但存在以植入物为中心的感染问题。随着鲍曼不动杆菌和耐甲氧西林金黄色葡萄球菌等微生物对抗生素产生耐药性，需要新的抗菌递送机制且不存在产生耐药菌的风险。
通过在PMMA中原位生成银纳米颗粒（AgNP）来开发一种新型抗菌植入材料。
所有含有AgNP的PMMA样品（AgNP-PMMA）在体外释放Ag(+)离子超过28天。体外抗菌试验表明，这些样品（即使是释放速率最慢的样品）对四种不同菌株的细菌抑制率达99.9%。长期抗菌试验显示，在28天之后仍有持续的抗菌效果。一些负载AgNP的PMMA组的邵氏D硬度（一种固化程度的度量）和模量与对照PMMA相当，但所有实验组的极限横向强度略低。
AgNP-PMMA表现出极其广谱且中长期的抗菌效果，其机械性能与对照PMMA相当。目前的工作重点是通过减少AgNP负载量进一步改善机械性能并评估疲劳性能。
