Dexamethasone Eluting 3D Printed Metal Devices for Bone Injuries

Abstract

Aim: Additively manufactured (3D printed), stainless steel implants were coated with dexamethasone using gelatin, chondroitin sulfate for use in bone graft surgeries. Materials & methods: The drug and polymers were deposited on the implants with a rough surface using a high precision air brush. The gelatin-chondroitin sulfate layers were cross-linked using glutaraldehyde. Results: The drug content uniformity was within 100 ± 5%, and the thickness of the polymer layer was 410 ± 5.2 μm. The in vitro release studies showed a biphasic pattern with an initial burst release followed by slow release up to 3 days. Conclusion: These results are very promising as the slow release implants can be further tested in vivo in large animals, such as cattle and horses to prevent the inflammatory cascade following surgeries.

3D-Printing of Drug-Eluting Implants: An Overview of the Current Developments Described in the Literature

“…As a postprinting procedure, finished drug-free 3D-printed implants can be loaded with drugs by a coating procedure [ 62 , 63 ]. Furthermore, drug solutions can be applied dropwise on the printed object [ 64 , 65 , 66 ] or the whole implant can be immersed in a drug solution, often under vacuum, to absorb the drug [ 67 , 68 , 69 , 70 , 71 , 72 ].…”

“…Furthermore, implant-associated infections can be caused by contamination during surgical procedures [ 127 ]. Antimicrobial drugs, for example isoniazide, rifampicin, minocycline, gentamicin or vancomycin have been used for the 3D-printing of implants in the sector of bone treatment in several studies [ 35 , 44 , 46 , 54 , 55 , 56 , 57 , 59 , 60 , 68 , 72 , 128 , 129 , 130 , 131 , 132 ], and glucocorticoids such as dexamethasone or prednisolone have been incorporated in those products as well [ 63 , 133 , 134 , 135 ]. 3D-printing could be used for the manufacture of individually adjusted implant shapes to treat or prevent infection of the bone and surrounding tissues.…”

“…Besides the already mentioned materials, metals can also be used for 3D-printing of implants in bone treatment, manufactured via SLM possibly followed by a coating process to include the drug. Han et al [ 132 ] coated 3D-printed scaffolds of cobalt-chromium-molybdenum (CoCrMo) successfully with the antibacterial drug gentamicin by an electrophoretic deposition method, whereas Poudel et al [ 63 ] used an air-brush technique for drug coating of previously 3D-printed objects made of stainless steel. Both enabled the combination of the mechanical properties of metal materials with drug release for improved therapy and an easily adjustable shape by 3D-printing.…”

Gentamicin Eluting 3D-Printed Implants for Preventing Post-Surgical Infections in Bone Fractures

“…Surface texture effects have been proven to be extremely crucial in achieving the final constructs with fatigue resistance . Surface roughness plays a vital role in deciding the coat’s thickness, the release of actives, and the surface morphology when intended for coating the implants by AM . In addition to surface roughness and mechanical strength, the creation of surface porosities is an essential approach for implants to allow osseointegration to set up the interconnections between the implant and the osseous tissue, allowing effective regeneration, while leaving surrounding tissues unaltered …”

“…13,47 Such implants could be custom modified not just based on the nature of the injury but also could facilitate alterations in surface roughness, topography, and drug loading. 15,48 The customized implants also provide flexibility with site specificity of multifunctional coatings, 17 improve osseointegration, 3 and antibacterial deposition. 20,34 Such implant was utilized as a model orthopedic device, but it does not limit the potential of fabrication using AM and coating using precision airbrush coating solely on bone support implants alone.…”