3D Printed Multiphasic Scaffolds for Osteochondral Repair: Challenges and Opportunities

Abstract

Osteochondral (OC) defects are debilitating joint injuries characterized by the loss of full thickness articular cartilage along with the underlying calcified cartilage through to the subchondral bone. While current surgical treatments can provide some relief from pain, none can fully repair all the components of the OC unit and restore its native function. Engineering OC tissue is challenging due to the presence of the three distinct tissue regions. Recent advances in additive manufacturing provide unprecedented control over the internal microstructure of bioscaffolds, the patterning of growth factors and the encapsulation of potentially regenerative cells. These developments are ushering in a new paradigm of ‘multiphasic’ scaffold designs in which the optimal micro-environment for each tissue region is individually crafted. Although the adoption of these techniques provides new opportunities in OC research, it also introduces challenges, such as creating tissue interfaces, integrating multiple fabrication techniques and co-culturing different cells within the same construct. This review captures the considerations and capabilities in developing 3D printed OC scaffolds, including materials, fabrication techniques, mechanical function, biological components and design.

Within or Without You? A Perspective Comparing In Situ and Ex Situ Tissue Engineering Strategies for Articular Cartilage Repair

“…A large number of such biofabrication studies assess capacity for repair in small animal models, especially rabbits, and these have been reviewed by others. [115,266] Only a few of these advanced strategies have been applied to large animal models, and none yet to humans. For example, He et al generated cartilage ex situ by culturing autologous BM-MSCs on a PGA/PLA scaffold for various time periods (2, 4, or 8 weeks) before implanting in a pig model of an osteochondral defect.…”

“…Cartilage consists of multiple zones of varying composition and the ex situ strategy offers more freedom to create a multiphasic construct in terms of materials, cellular content and/or design. [24,115] While the potential benefits of complex chondral implants is a matter of ongoing debate, [116] and promising results have been achieved using homogenous as well as zonally layered implants. [90,102] the ability to create multiphasic designs is currently limited when the in situ approach is employed.…”

Recent development in multizonal scaffolds for osteochondral regeneration

“…6 D schematically illustrates a few representative contact and noncontact 3D printing techniques that are commonly used to manufacture cellular and acellular scaffolds for tissue engineering [ 289 ]. The working principles and detailed mechanisms of these processes have been reported [ 289 , 300 , 304 , 305 ]. Thereinto, extrusion-based printing is considered the most prevalently implemented strategy to produce cell-free or cell-laden hydrogels and scaffolds for tissue regeneration and has been gaining momentum in recent years [ 121 , 289 , [305] , [306] , [307] , [308] , [309] , [310] ].…”

“…The working principles and detailed mechanisms of these processes have been reported [ 289 , 300 , 304 , 305 ]. Thereinto, extrusion-based printing is considered the most prevalently implemented strategy to produce cell-free or cell-laden hydrogels and scaffolds for tissue regeneration and has been gaining momentum in recent years [ 121 , 289 , [305] , [306] , [307] , [308] , [309] , [310] ]. Fig.…”

The Transfer Film Effects Induced by 3D Printing Polyether-ether-ketone with Excellent Tribological Properties

“…3D printing, also known as additive manufacturing, is a process of accumulating materials layer by layer to construct products, among which fused lament fabrication (FFF) can control the distribution of μm materials in the three-dimensional direction by adjusting the real-time powder feeding amount, and then achieve different functions in different regions [29][30][31][32][33]. The building principle of 3D printing determines that the surfaces of specimens are formed by regularly arranged laments, even after polishing.…”