Fabrication of Isoniazid/Rifampicin/Poly L-lactic Acid Donut-shaped Implants via Three Dimensional Printing Technique

Objective To investigate the possibility of manufacturing dual-drug loaded isoniazid/rifampicin/poly L-lactic acid (PLLA) implant with donut-shaped structure via three-dimensional (3D) printing technique and study the drug release characteristic and biocompatibility of the implant in vitro.Methods PLLA was crushed into particles with diameters around 75-100 μm.Isoniazid and rifampicin bulk drugs were dissolved into the organic dissolvent respectively to be the binding liquid.The 3D printing machine fabricated the donut-shaped implant via binding the PLLA powder layer by layer.Dynamic socking method was used to study the in vitro release characteristics,and cell culture experiment was used to test the cytocompatibility of the implant.Results PLLA slow-release implants were made by using the PLLA powder as matrix and isoniazid/rifampicin organic solvent as binding liquid through 3D printing.The drugs in the implants distributed in nest under electron microscope.The concentrations of both drugs were still higher than the lowest effective bacteriostasis concentration after release for 32 days.Cytotoxicity and direct contact tests indicated that the implants had rare cytotoxicity and favorable biocompatibility. Conclusion The donut-shaped implants can be successfully fabricated using the 3D printing method,which offers a new method for the manufacturing of topical slow-release anti-tuberculosis drugs.