Bezuidenhout Martin B, Booysen Elzaan, van Staden Anton D, Uheida Emad H, Hugo Philippus A, Oosthuizen Gert A, Dimitrov Dimiter M, Dicks Leon M T
Stellenbosch Technology Centre, Department of Industrial Engineering, Stellenbosch University, Room B2005, Industrial Engineering Building (Entrance 6), Banghoek Road, Stellenbosch 7600, South Africa.
Department of Microbiology, Stellenbosch University, Third Floor, J.C. Smuts Building, De Beer Street, Stellenbosch 7600, South Africa.
ACS Biomater Sci Eng. 2018 Dec 10;4(12):4412-4424. doi: 10.1021/acsbiomaterials.8b00676. Epub 2018 Nov 2.
Bacteria colonizing the surface of orthopedic implants are responsible for most postoperative periprosthetic joint infections. A possible alternative route for drug delivery is described in this study by utilizing the bulk of the implant itself as a reservoir. Drug release is enabled by manufacturing of integrated permeable structures possessing high porosity through application of selective laser melting technology. The concept was evaluated in two paths, with 400 μm permeable thin walls and with dense reservoirs containing an integrated 950 μm permeable wall. Components were designed and preprocessed as separate parts, allowing for allocation of different settings of laser power and scanning speed. Lowering the energy input into the selective laser melting process to induce intermittent melting of the Ti6Al4V ELI powder produced porous components through which vancomycin was released with differing profiles. Static water contact angle measurements demonstrated a significant effect on the hydrophilicity by permeable wall thickness. Relative porosities of the 400 μm structures were determined with microcomputed tomography analyses. A transition zone of 21.17% porosity was identified where release profiles change from porosity-dependent to near free diffusion. Antimicrobial activity of released vancomycin was confirmed through evaluation against Xen 36 in two separate agar diffusion assays. The approach is promising for incorporation into the design and manufacturing of next-generation prosthetic implants with controlled release of antibiotics in situ and the subsequent prevention of periprosthetic joint infections.
定植于骨科植入物表面的细菌是大多数术后假体周围关节感染的病因。本研究描述了一种可能的药物递送替代途径，即利用植入物本身作为储库。通过应用选择性激光熔化技术制造具有高孔隙率的整体可渗透结构来实现药物释放。该概念通过两条路径进行评估，一条路径是具有400μm可渗透薄壁，另一条路径是具有包含950μm整体可渗透壁的致密储库。组件被设计并预先加工成单独的部件，允许分配不同的激光功率和扫描速度设置。降低选择性激光熔化过程中的能量输入以诱导Ti6Al4V ELI粉末间歇性熔化，从而产生多孔组件，万古霉素通过这些组件以不同的方式释放。静态水接触角测量表明可渗透壁厚度对亲水性有显著影响。通过微计算机断层扫描分析确定了400μm结构的相对孔隙率。确定了一个孔隙率为21.17%的过渡区,在该区域释放曲线从孔隙率依赖性转变为近自由扩散。通过在两项单独的琼脂扩散试验中对Xen 36进行评估，证实了释放的万古霉素的抗菌活性。该方法有望应用于下一代假体植入物的设计和制造，实现抗生素的原位控释，并随后预防假体周围关节感染。
