3D-Printed Structures for Bone Fracture and Wound Healing Applications

Abstract

3D printing (3DP) technique has been developed and evolved in multiple applications over the past decades. They are widely used in biomedical devices, disease models, diagnostic platforms, and regenerative medicine. In the drug delivery field, the 3D printing method can fabricate delivery systems with patient-specific and functionalized properties. The structures can be designed on demand with computer-aided design (CAD) models. 3D printing allows precise spatial control over physical geometry, drug distribution, and release kinetics. It leverages the difference in printing parameters and processes to achieve personalized characteristics such as mechanical strength, drug loading, release patterns, and improved therapeutic outcomes. In addition, recent advances in 3DP have integrated biomolecules, living cells, or growth factors into the printed structures. It promotes the delivery system to exert biological activity in the body. The personalization of 3DP makes it possible to become a flexible platform for delivering drugs to target sites in various disease models. In this dissertation, we elucidate the cutting-edge developments in 3D printing for the advancement of drug delivery and regenerative medicine. Our research is expanding from infection prevention to tissue regeneration. We investigated various polymer-based coatings on 3D-printed metal implants and hydrogel-based 3D-printed scaffolds. They were designed with optimized structural compositions and predicted release profiles. Chapter 1 is an overview of 3D printing innovations in organ-specific drug delivery and regenerative medicine. Various 3DP techniques and printable polymers for drug delivery are introduced in this chapter. 3D printing can be adapted to multiple organs for different disease models to achieve localized treatment. Moreover, we discuss the advantages and challenges of existing 3D printing techniques to provide new insights into the novelty of this approach. The current preclinical and clinical trials of 3DP products prove the feasibility and effectiveness of the novel therapies. Upcoming next-generation technologies are also included in this chapter for advancements in drug delivery systems. In Chapter 2, we examined the performance of amikacin-coated 3D-printed metal implants for reducing postsurgical infection via an advanced manufacturing technique accompanied by localized antibacterial therapy. The 3D printing method provides an ideal platform for personalized drug-loaded coatings with designed structures and predefined kinetics for controlled release. The research aims to fabricate an amikacin-loaded chitosan coating and subsequently coat a PLGA layer onto the metal implant, designed for application in postsurgical infections. The formulation was evaluated for its physicochemical properties, drug release behavior, kinetic models, and antimicrobial efficacy against microorganisms. The findings will serve as evidence to adopt the novel coated implants as an effective strategy for enhancing surface biocompatibility, minimizing the chances of postsurgical infection, and improving the outcomes of surgery. In Chapter 3, we investigated novel co-drug-loaded hydrogel-based scaffolds through 3D printing to enhance wound healing. The designed delivery system aims to provide a dual-drug release profile with a synergetic effect. It would provide antibacterial activity and facilitate the proliferation of fibroblasts. 3DP drug delivery devices were successfully developed by optimizing the printing parameters, and their physicochemical properties were also investigated. In addition, preliminary antibacterial function was tested against pathogens, and its compatibility with human dermal fibroblasts was evaluated. The 3D-printed collagen-chitosan scaffolds are a novel strategic approach for introducing co‑drug delivery into personalized therapy. The combined therapy presents its potential to effectively prevent infection and aid in wound healing.