Hybrid Three‐Dimensional–Printed Ear Tissue Scaffold With Autologous Cartilage Mitigates Soft Tissue Complications

Abstract

Objectives/Hypothesis To analyze the use of highly translatable three‐dimensional (3D)–printed auricular scaffolds with and without novel cartilage tissue inserts in a rodent model. Study Design Preclinical rodent animal model. Methods This prospective study assessed a single‐stage 3D‐printed auricular bioscaffold with or without porcine cartilage tissue inserts in an athymic rodent model. Digital Imaging and Communications in Medicine computed tomography images of a human auricle were segmented to create an external anatomic envelope filled with orthogonally interconnected spherical pores. Scaffolds with and without tissue inset sites were 3D printed by laser sintering bioresorbable polycaprolactone, then implanted subcutaneously in five rats for each group. Results Ten athymic rats were studied to a goal of 24 weeks postoperatively. Precise anatomic similarity and scaffold integrity were maintained in both scaffold conditions throughout experimentation with grossly visible tissue ingrowth and angiogenesis upon explantation. Cartilage‐seeded scaffolds had relatively lower rates of nonsurgical site complications compared to unseeded scaffolds with relatively increased surgical site ulceration, though neither met statistical significance. Histology revealed robust soft tissue infiltration and vascularization in both seeded and unseeded scaffolds, and demonstrated impressive maintenance of viable cartilage in cartilage‐seeded scaffolds. Radiology confirmed soft tissue infiltration in all scaffolds, and biomechanical modeling suggested amelioration of stress in scaffolds implanted with cartilage. Conclusions A hybrid approach incorporating cartilage insets into 3D‐printed bioscaffolds suggests enhanced clinical and histological outcomes. These data demonstrate the potential to integrate point‐of‐care tissue engineering techniques into 3D printing to generate alternatives to current reconstructive surgery techniques and avoid the demands of traditional tissue engineering. Level of Evidence NA Laryngoscope, 131:1008–1015, 2021

Models of Cochlea Used in Cochlear Implant Research: A Review

“…In general, tissueengineered models are often constructed using scaffolds that support the growth and organisation of cells into tissues. For cochleae, there have been examples of organoid cultures [84] and decellularised tissues [100] for cochlear tissue engineering although more extensive studies of producing replacement tissues have been discussed for the middle and outer ear [3,5,22]. Lastly, computational models are increasingly being used to study the electrical and mechanical properties of the cochlea and the effects of CIs on the auditory system [7,14,110,118].…”

3D bioprinting strategies and their application in studies in vivo and in vitro animal models for skin regeneration: a concise systematic review and meta-analysis

“…Brian Chang et al 2020 [28] 10 athymic mice Cartilage-seeded scaffolds had relatively lower rates of non-surgical site complications compared to nonseeded scaffolds, which had greater surgical site ulceration, although neither was statistically significant.…”

Establishing a point-of-care additive manufacturing workflow for clinical use

“…More widely known is 3-D printing’s application in mandibular and maxilla reconstructive surgeries, wherein new grafts can be similarly pre-bent and sculpted to the original anatomy, or the 3-D patient models can be constructed to mirror the opposing anatomy and ultimately also decrease intraoperative timing [ 99 – 101 ]. Among others, there is further utility in otolaryngology for OSA [ 102 ], auricular scaffolds [ 103 ], nasal septal perforation and scaffolding [ 104 ], and in skull-based surgery [ 71 ]. As a wide-ranging preoperative tool, 3D printing remains well integrated into many fields including plastic surgery, urology, orthopedics, and hepatobiliary surgery among many others helping to depict and better navigate abnormal anatomy for favorable patient outcomes [ 105 – 108 ].…”

“…These scaffolds are then implanted with living stem cells and tissue components. For example, Zopf et alsuccessfully 3-D-printed a nasal and ear scaffold layered in chondrogenic growth factors that led to cartilage growth and Chang et al3-D-printed a bio-scaffold implanted with mesenchymal stem cells that grew into tracheas used in rabbits [ 103 , 109 , 142 ].…”