Customized Additive Manufacturing in Bone Scaffolds-The Gateway to Precise Bone Defect Treatment

Abstract

In the advancing landscape of technology and novel material development, additive manufacturing (AM) is steadily making strides within the biomedical sector. Moving away from traditional, one-size-fits-all implant solutions, the advent of AM technology allows for patient-specific scaffolds that could improve integration and enhance wound healing. These scaffolds, meticulously designed with a myriad of geometries, mechanical properties, and biological responses, are made possible through the vast selection of materials and fabrication methods at our disposal. Recognizing the importance of precision in the treatment of bone defects, which display variability from macroscopic to microscopic scales in each case, a tailored treatment strategy is required. A patient-specific AM bone scaffold perfectly addresses this necessity. This review elucidates the pivotal role that customized AM bone scaffolds play in bone defect treatment, while offering comprehensive guidelines for their customization. This includes aspects such as bone defect imaging, material selection, topography design, and fabrication methodology. Additionally, we propose a cooperative model involving the patient, clinician, and engineer, thereby underscoring the interdisciplinary approach necessary for the effective design and clinical application of these customized AM bone scaffolds. This collaboration promises to usher in a new era of bioactive medical materials, responsive to individualized needs and capable of pushing boundaries in personalized medicine beyond those set by traditional medical materials.

Fig. 1.

The correlation between the customized AM scaffold and the treatment of bone defects.

Fig. 2.

The clinical applications/studies of customized AM scaffolds on different types of bones. Pictures are adapted with permission from refs. ▽1 [253], ▽2 [254], ▽3 [255], ▽4 [31], ▽5 [36], ▽6 [256], ▽7 [23], ▽8 [41], and ▽9 [257].

Fig. 3.

The selection panel of materials for customized AM scaffolds. (A) Application scenarios. (B) Properties of different types of materials and their applicable scenarios. Pictures are adapted with permission from refs. ▽1 [258], ▽2 [259], ▽3 [260], ▽4 [261], and ▽5[262]. PGA, poly(glycolic acid).

Fig. 4.

The fabrication methods for customized AM scaffolds. (A) Methods based on UV light-solidification techniques (left: selective laser SLA, right: DLP). (B) Methods based on the direct deposition techniques (left: FDM, right: robocasting). (C) Methods based on the powder bed technique with different powder binding mechanisms (left: SLS/SLM, middle: binder jetting, right: EBM).

Fig. 5.

The flow chart shows the process of customizing the AM scaffold for a patient. Pictures are adapted with permission from refs. ▽1 [30] and ▽2 [36].