Engineered Regenerative Isolated Peripheral Nerve Interface for Targeted Reinnervation.

A regenerative peripheral nerve interface (RPNI) offers a therapeutic solution for nerve injury through reconstruction of the target muscle. However, implanting a transected peripheral nerve into an autologous skeletal muscle graft in RPNI causes donor-site morbidity, highlighting the need for tissue-engineered skeletal muscle constructs. Here, an engineered regenerative isolated peripheral nerve interface (eRIPEN) is developed using 3D skeletal cell printing combined with direct electrospinning to create a nanofiber membrane envelop for host nerve implantation.

A Bioprinted Bruch's Membrane for Modeling Smoke-Induced Retinal Pigment Epithelium Degeneration via Hybrid Membrane Printing Technology.

The retinal pigment epithelium (RPE) not only forms the outer blood-retinal barrier (oBRB) but also plays a multifunctional role in the ocular system. The loss of this epithelium leads to serious diseases resulting in vision impairment. No effective treatment is available for the repair of RPE damage.

Three-Dimensional Microfilament Printing of a Decellularized Extracellular Matrix (dECM) Bioink Using a Microgel Printing Bath for Nerve Graft Fabrication and the Effectiveness of dECM Graft Combined with a Polycaprolactone Conduit.

Various synthetic and decellularized materials are being used to reconstruct peripheral nerve defects and replace autologous nerve grafts. In this study, we developed a microgel printing bath to three-dimensionally (3D) print a peripheral nervous system decellularized extracellular matrix nerve graft reinforced by a polycaprolactone (PCL) conduit. The straightforward fabrication method of an alginate microgel-supplemented printing bath allows a 30 μm filament resolution of a low viscous decellularized extracellular matrix hydrogel with neutral pH.

Promoting Long-Term Cultivation of Motor Neurons for 3D Neuromuscular Junction Formation of 3D In Vitro Using Central-Nervous-Tissue-Derived Bioink.

3D cell printing technology is in the spotlight for producing 3D tissue or organ constructs useful for various medical applications. In printing of neuromuscular tissue, a bioink satisfying all the requirements is a challenging issue. Gel integrity and motor neuron activity are two major characters because a harmonious combination of extracellular materials essential to motor neuron activity consists of disadvantages in mechanical properties.

Maturation and Protection Effect of Retinal Tissue-Derived Bioink for 3D Cell Printing Technology.

Retinal degeneration is a leading cause of incurable vision loss and blindness. The increasing incidence of retinal degeneration has triggered research into the development of in vitro retinal models for drug development and retinal alternatives for transplantation. However, the complex retinal structure and the retinal microenvironment pose serious challenges.

Development of 3D Printed Bruch's Membrane-Mimetic Substance for the Maturation of Retinal Pigment Epithelial Cells.

Retinal pigment epithelium (RPE) is a monolayer of the pigmented cells that lies on the thin extracellular matrix called Bruch's membrane. This monolayer is the main component of the outer blood-retinal barrier (BRB), which plays a multifunctional role. Due to their crucial roles, the damage of this epithelium causes a wide range of diseases related to retinal degeneration including age-related macular degeneration, retinitis pigmentosa, and Stargardt disease.

Flexible Adipose-Vascular Tissue Assembly Using Combinational 3D Printing for Volume-Stable Soft Tissue Reconstruction.

A new concept, assembling cell-laden tissue modules, is for the first time proposed for soft tissue engineering. Adipose-vascular tissue modules composed of a synthetic polymer-based substructure and customized bioinks using planar 3D cell printing are engineered. Such tissue modules are systematically assembled into a synthetic polymer-based module holder fabricated with rotational 3D printing, resulting in the development of a flexible and volumetric tissue assembly.

3D Cell Printing of Tissue/Organ-Mimicking Constructs for Therapeutic and Drug Testing Applications.

The development of artificial tissue/organs with the functional maturity of their native equivalents is one of the long-awaited panaceas for the medical and pharmaceutical industries. Advanced 3D cell-printing technology and various functional bioinks are promising technologies in the field of tissue engineering that have enabled the fabrication of complex 3D living tissue/organs. Various requirements for these tissues, including a complex and large-volume structure, tissue-specific microenvironments, and functional vasculatures, have been addressed to develop engineered tissue/organs with native relevance.

Decellularized extracellular matrix bioinks and the external stimuli to enhance cardiac tissue development in vitro.

Engineered heart tissue (EHT) has ample potential as a model for in vitro tissue modeling or tissue regeneration. Using 3D cell printing technology, various hydrogels have been utilized as bioinks to fabricate EHT to date. However, its efficacy has remained limited due to poor functional properties of the cultured cardiomyocytes stemming from a lack of proper microenvironmental cues.

A 3D cell printed muscle construct with tissue-derived bioink for the treatment of volumetric muscle loss.

Volumetric muscle loss (VML) is an irrecoverable injury associated with muscle loss greater than 20%. Although hydrogel-based 3D engineered muscles and the decellularized extracellular matrix (dECM) have been considered for VML treatment, they have shown limited efficacy. We established a novel VML treatment with dECM bioink using 3D cell printing technology.

3D cell printing of in vitro stabilized skin model and in vivo pre-vascularized skin patch using tissue-specific extracellular matrix bioink: A step towards advanced skin tissue engineering.

3D cell-printing technique has been under spotlight as an appealing biofabrication platform due to its ability to precisely pattern living cells in pre-defined spatial locations. In skin tissue engineering, a major remaining challenge is to seek for a suitable source of bioink capable of supporting and stimulating printed cells for tissue development. However, current bioinks for skin printing rely on homogeneous biomaterials, which has several shortcomings such as insufficient mechanical properties and recapitulation of microenvironment.

Three-dimensional bioprinting of cell-laden constructs with polycaprolactone protective layers for using various thermoplastic polymers.

Three-dimensional (3D) cell-printed constructs have been recognized as promising biological substitutes for tissue/organ regeneration. They provide tailored physical properties and biological cues via multi-material printing process. In particular, hybrid bioprinting, enabling to use biodegradable synthetic polymers as framework, has been an attractive method to support weak hydrogels.