3D Printing of Microgel‐Loaded Modular Microcages as Instructive Scaffolds for Tissue Engineering

Abstract

Biomaterial scaffolds have served as the foundation of tissue engineering and regenerative medicine. However, scaffold systems are often difficult to scale in size or shape in order to fit defect‐specific dimensions, and thus provide only limited spatiotemporal control of therapeutic delivery and host tissue responses. Here, a lithography‐based 3D printing strategy is used to fabricate a novel miniaturized modular microcage scaffold system, which can be assembled and scaled manually with ease. Scalability is based on an intuitive concept of stacking modules, like conventional toy interlocking plastic blocks, allowing for literally thousands of potential geometric configurations, and without the need for specialized equipment. Moreover, the modular hollow‐microcage design allows each unit to be loaded with biologic cargo of different compositions, thus enabling controllable and easy patterning of therapeutics within the material in 3D. In summary, the concept of miniaturized microcage designs with such straight‐forward assembly and scalability, as well as controllable loading properties, is a flexible platform that can be extended to a wide range of materials for improved biological performance.

Prevascularized hydrogels with mature vascular networks promote the regeneration of critical‐size calvarial bone defects in vivo

“…In this study, one or more of the above mechanisms might be critical for the enhanced bone generation in the mature prevascularized hydrogel grafts. Although the proposed vascularization strategy has been tested using soft hydrogels for the regeneration of nonload‐bearing calvarial bone, it should be noted that this system may be applied in the load‐bearing bone injuries with either ceramic or polymeric scaffold systems that are compatible with hydrogel loading (Subbiah et al., 2020b).…”

3D printing of tissue engineering scaffolds: a focus on vascular regeneration

“…Common processes for preparing connectors include 3D printing or the combination of 3D printing and casting. Subbiah et al [ 149 ] designed a miniaturized hollow microcage as the basic module for assembly. A miniature basic module with a volume of 3.375 mm 3 , a hollow size of 1.5 × 1.5 × 1.5 mm and a wall thickness of 230–560 µm, was constructed by DLP 3D printing.…”

“…polyethylene glycol + 60% wt. polyethylene (glycol) diacrylate Synthetic material Polycaprolactone + gelatin 15% w/v polycaprolactone + 20% w/v gelatin [ 145 ] Lego-like construction and extrusion and FDM and casting Bioinks excluding cells (alginate hydrogel for extrusion); biomaterial inks (maltitol for FDM) 3% w/v sodium alginate; fused maltitol Natural material (sodium alginate); synthetic material (maltitol) PDMS PDMS prepared by mixing the base and curing agents at 10:1 (w/w) ratio [ 151 ] Lego-like construction and stereolithography (DLP) Biomaterial inks (GelMA + ceramic) 7-9% w/v GelMA + ceramic with high density (97%) Compositive material N/A N/A [ 149 ] Lego-like construction and stereolithography (DLP) and casting Biomaterial inks (a clear resin consists of triethylene glycol diacrylate and isobornyl methacrylate) A resin with a component concentration described in the product information Compositive material Gold and PDMS 20 nm thick gold + PDMS with a 10:1 ratio of base to curing agent [ 152 ] Lego-like construction and stereolithography (SLA) Biomaterial inks (poly(ethylene glycol) diacrylate + poly(acrylic acid)) 10% w/v poly(ethylene glycol) diacrylate + 5% w/v poly(acrylic acid) Compositive material N/A N/A [ 150 ] …”

3D Tissue and Organ Printing—Hope and Reality

“…This could be done, for example, by enabling the clinician to produce patient-specific geometries from pre-printed building blocks without the need for special equipment or long training. Such an approach was elegantly demonstrated by Subbiah et al [79] The group used lithography-based 3D printing to construct a microcage scaffold assembly system for regeneration of hard tissues. The rigid, miniaturized, stackable microcage modules could be manually assembled and scaled by the user to generate the required geometry.…”