Researchers from伦敦大学学院（UCL）have 3D printed antibacterial hearing aids which could help prevent ear infections from forming after prolonged use.
通过数字光处理（DLP）方法制造，助听器装有两种抗生素，环丙沙星和氟诺酮，并从两个聚合物树脂中生产，这些聚合物树脂硬且柔韧性。该研究突出了增值税光聚合3D打印技术在具有抗菌特性的患者特异性医疗设备中的潜力。
3D printing custom hearing aids
Hearing aids are one of the paramount examples of how personalized medical devices have benefitted from the development of 3D printing. In fact, according to Belgian software and 3D printing service providerMaterialisesome全球99％的助听器are now custom-manufactured through 3D printing.
除了实现，全球制造商，例如EnvisionTEC,Formlabs， 和Sonovahave also been 3D printing hearing aids and custom earpieces for years.
In 2017, EnvisionTEC announced a new partnership with 3D scanning and software company3Shapetocontinue offering 3D printed in-ear devices, while at CES 2018 Formlabs also partnered with 3Shape to showcase the combined power of its Form 2 3D printer and 3Shape’s Phoenix in-ear scanner to make定制耳塞。
Having started using 3D printers to manufacture hearing aids in the early 2000s, Sonova and its subsidiary brandPhonak每年生产数十万个定制助听器。在2017年，该公司生产了first titanium 3D printed hearing aid, Virto B-Titanium, using powder bed fusion (PBF) metal additive manufacturing.
在其他地方，澳大利亚听力公司Lably Saunders听到了介绍了“世界第一” 3D印刷模块化，可自动助听器具有智能手机控制。该项目的主要目的也看到了Extel Technologies, Melbourne-basedRMIT University， 和Swinburne University，是为了消除与听力损失相关的社会污名。
通过DLP制造助听器
The prolonged use of hearing aids can alter the ear canal microbiota and increase the risk of fungal and bacterial infections. According to the UCL researchers, treating ear infections with topical antibiotics is far more effective than ear cleaning alone, however hearing aids with anti-biofilm properties are yet to be developed in any real capacity.
Therefore, the scientists set out on a mission to employ DLP 3D printing to manufacture drug-loaded hearing aids for patients with ear infections. If successful, the novel drug-device combination could help to avoid the discontinuation of hearing aids due to infections. Ciprofloxacin and fluocinolone acetonide were chosen for the drug combination, as they are commonly used in ear drops used to treat ear infections.
To prepare the photopolymer solutions, Flexible resin and ENG hard resin were mixed with 12% ciprofloxacin and 0.5% fluocinolone acetonide. The resulting photopolymer solution was then loaded into aKudo3DTitan 2 HR 3D printer, equipped with a digital light projector optimized for printing the hearing aids. Templates were then used to print the hearing aids, having been obtained from the molds of the right ears of two volunteers and exported as a stereolithography file into Kudo3D’s 3D printing software. Once printed, the hearing aids were washed in isopropyl alcohol and cured for an hour at 60°C with UV-visible light.
During testing, the drug-loaded hearing devices exhibited efficient anti-biofilm activity and completely inhibited the growth of bacteria on the surface of the devices. When examining the drug release properties of the hearing aids, it was observed that the DLP 3D printed drug-loaded discs sustained the release of both ciprofloxacin and fluocinolone acetonide for more than seven days, continuing thereafter at much slower rates. Otitis, or inflammation of the ear, generally requires between one and two weeks of pharmacological treatment, indicating the researchers’ drug-loaded devices would provide effective treatment across the required time period.
吸毒助听器的意义
Through this study, the UCL researchers have successfully demonstrated the ability to incorporate a combination of drugs, typically used as ear drops to treat ear infections, into DLP 3D printed hearing aids to prevent and treat biofilm-related infections.
DLP过程的灵活性使助听器的个性化适合患者的耳朵解剖结构。与其他制造方法（例如成型）相比，当生产量较低并避免制造模具时，发现DLP 3D打印是具有成本效益的，这需要在机械，材料和人工上付出额外的费用。
科学家现在正在寻求通过调查将DLP 3D打印和人工耳蜗的可行性扩展其工作的适用性。概念验证研究也可以过渡并扩展，以治疗其他不同设备的其他疾病，从而实现了更高水平的个性化治疗方法。
The full study can be found in the paper titled“Anti-biofilm multi drug-loaded 3D printed hearing aids”发表在ScienceDirect杂志上。该研究由M. Vivero-Lopez，X. Xu，A。Muras，A。Otero，A。Concheiro，S。Gaisford，A。Basit，C。Alvarez-Lorenzon和A. Goyanes共同撰写。
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特色图表（a）助听器的3D扫描模型；DLP 3D打印的助听器使用（b）Eng硬树脂和（c）柔性树脂。通过ScienceDirect图像。
