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Complexation-induced resolution enhancement of 3D-printed hydrogel constructs

Three-dimensional (3D) hydrogel printing enables production of volumetric architectures containing desired structures using programmed automation processes. Our study reports a unique method of resolution enhancement purely relying on post-printing treatment of hydrogel constructs. By immersing a 3D-printed patterned hydrogel consisting of a hydrophilic polyionic polymer network in a solution of polyions of the opposite net charge, shrinking can rapidly occur

Novel bioinks from UV-responsive norbornene-functionalized carboxymethyl cellulose macromers

3D printing has significantly progressed in the past decade and become a potentially powerful biomanufacturing approach for tissue and organ printing. Availability of diverse hydrogel-based bioink formulations, particularly bioinks allowing biochemical functionalization, stimuli responsiveness, and control over mechanical and degradation properties are crucial for bioprinting to reach its full potential. In this study, we report two novel bioink platforms from

Printing 3D Hydrogel Structures Employing Low-Cost Stereolithography Technology

Stereolithography technology associated with the employment of photocrosslinkable, biocompatible, and bioactive hydrogels have been widely used. This method enables 3D microfabrication from images created by computer programs and allows researchers to design various complex models for tissue engineering applications. This study presents a simple and fast home-made stereolithography system developed to print layer-by-layer structures. Polyethylene glycol diacrylate (PEGDA) and gelatin

3D Bioprinting of Methylcellulose/Gelatin-Methacryloyl (MC/GelMA) Bioink with High Shape Integrity

The advent of three-dimensional (3D) bioprinting offers a feasible approach to construct complex structures suitable for tissue regeneration, during which cell-laden materials are dispensed on a substrate according to a predesigned structure. However, the lack of ideal printable bioinks with high shape fidelity and improved biological stability remains a major challenge. In this study, methylcellulose/gelatin-methacryloyl (MC/GelMA) bioink with high shape

Immersion Bioprinting of Tumor Organoids in Multi-Well Plates for Increasing Chemotherapy Screening Throughput.

The current drug development pipeline takes approximately fifteen years and $2.6 billion to get a new drug to market. Typically, drugs are tested on two-dimensional (2D) cell cultures and animal models to estimate their efficacy before reaching human trials. However, these models are often not representative of the human body. The 2D culture changes the morphology and physiology of cells,

Inorganic Sol–Gel Polymerization for Hydrogel Bioprinting

An inorganic sol–gel polymerization process was used as a cross-linking reaction during three-dimensional (3D) bioprinting of cell-containing hydrogel scaffolds. Hybrid hydroxypropyl methyl cellulose (HPMC), with a controlled ratio of silylation, was prepared and isolated as a 3D-network precursor. When dissolved in a biological buffer containing human mesenchymal stem cells, it yields a bioink that can be printed during polymerization by

Easy-to-use and inexpensive sensors for assessing the quality and traceability of cosmetic antioxidants

We describe an easy-to-use sensor as a tool to quantify and authenticate antioxidant active ingredients in cosmetic products. The sensing platform comprises a responsive nanoengineered surface that reacts specifically and generates distinct optically detectable signals that are representative of the chemical composition and concentration of active ingredients. The platform can be inexpensively produced in large quantities and a procedure to

In Situ Printing of Adhesive Hydrogel Scaffolds for the Treatment of Skeletal Muscle Injuries

Reconstructive surgery remains inadequate for the treatment of volumetric muscle loss (VML). The geometry of skeletal muscle defects in VML injuries varies on a case-by-case basis. Three-dimensional (3D) printing has emerged as one strategy that enables the fabrication of scaffolds that match the geometry of the defect site. However, the time and facilities needed for imaging the defect site, processing

Experimental investigation into the fabrication of green body developed by micro‐extrusion‐based 3D printing process

In the present work, a micro‐extrusion‐based three‐dimensional (3D) printing process has been used to fabricate a metal‐polymer‐based green body. The fabricated parts consisted of carbonyl iron particles with a binder (polylactic acid) and a solvent mixture. From the pilot experiments, it was found that the process parameters, namely, Fe loading, layer thickness,and infill density, affect the green density, shrinkage, and surface

Freeze-FRESH: A 3D Printing Technique to Produce Biomaterial Scaffolds with Hierarchical Porosity.

Tissues are organized in hierarchical structures comprised of nanoscale, microscale, and macroscale features. Incorporating hierarchical structures into biomaterial scaffolds may enable better resemblance of native tissue structures and improve cell interaction, but it is challenging to produce such scaffolds using a single conventional scaffold production technique. We developed the Freeze-FRESH (FF) technique that combines FRESH 3D printing (3DP) and freeze-casting

Fiber engraving for bioink bioprinting within 3D printed tissue engineering scaffolds

In this work, we describe a new 3D printing methodology for the fabrication of multimaterial scaffolds involving the combination of thermoplastic extrusion and low temperature extrusion of bioinks. A fiber engraving technique was used to create a groove on the surface of a thermoplastic printed fiber using a commercial 3D printer and a low viscosity bioink was deposited into this

3D-printed electrodes for lithium metal batteries with high areal capacity and high-rate capability

Lithium metal is the ultimate solution for high-energy density batteries, but is currently plagued from commercialization by the safety issue due to the uncontrollable Li dendrite growth. It would be worse when plating a higher areal capacity of lithium operating under higher current densities. Herein, we develop a novel N-doped carbon framework by extrusion-based 3D-printing of Zn-MOF precursor, which possess

Cell death persists in rapid extrusion of lysis-resistant coated cardiac myoblasts

As the demand for organ transplants continues to grow faster than the supply of available donor organs, a new source of functional organs is needed. High resolution high throughput 3D bioprinting is one approach towards generating functional organs for transplantation. For high throughput printing, the need for increased print resolutions (by decreasing printing nozzle diameter) has a consequence: it increases

Miniaturized characterization of polymers: From synthesis to rheological and mechanical properties in 30 mg

The determination of rheological and mechanical material properties becomes a challenge when the availability of material is limited to a few (milli)grams. This miniaturized testing is hampered by the contradicting requirements of small sample sizes (and thus surface areas) and sufficiently large generated torques and forces. In this paper we provide a feasible methodology to determine the relevant material parameters

Freeform, Reconfigurable Embedded Printing of All‐Aqueous 3D Architectures

Aqueous microstructures are challenging to create, handle, and preserve since their surfaces tend to shrink into spherical shapes with minimum surface areas. The creation of freeform aqueous architectures will significantly advance the bioprinting of complex tissue‐like constructs, such as arteries, urinary catheters, and tracheae. The generation of complex, freeform, three‐dimensional (3D) all‐liquid architectures using formulated aqueous two‐phase systems (ATPSs) is

Glial cells influence cardiac permittivity as evidenced through in vitro and in silico models

Excitation–contraction (EC) coupling in the heart has, until recently, been solely accredited to cardiomyocytes. The inherent complexities of the heart make it difficult to examine non-muscle contributions to contraction in vivo, and conventional in vitro models fail to capture multiple features and cellular heterogeneity of the myocardium. Here, we report on the development of a 3D cardiac μTissue to investigate changes in the cellular composition

Optimization of 3D bioprinting of human neuroblastoma cells using sodium alginate hydrogel

There are many parameters in extrusion-based three-dimensional (3D) bioprinting of different materials that require fine-tuning to obtain the optimal print resolution and cell viability. To standardize this process, methods such as parameter optimization index (POI) have been introduced. The POI aims at pinpointing the optimal printing speed and pressure to achieve the highest accuracy keeping theoretical shear stress low. Here

Bovine colon organoids: From 3D bioprinting to cryopreserved multi-well screening platforms.

Three-dimensional (3D) colon organoids, termed “colonoids”, derived from adult stem cells represent a powerful tool in in vitro pharmaceutical and toxicological research. Murine and human colonoid models exist. Here we describe the establishment of bovine colonoids for agri-biotechnological applications, and extend the repertoire of colonoid culture options through proof-of-principle for bioprinting and novel in-plate cryopreservation technology. As a first step,

Chondroprotective and osteogenic effects of silk-based bioinks in developing 3D bioprinted osteochondral interface

Attributing cell instructive features and multifunctionality to biological inks (bioinks) employed for three-dimensional (3D) printing strategies is very much essential to bring about a paradigm shift in developing next generation smart intuitive 3D bioprinted constructs. Giving perspective to this notion, we explore here the feasibilities in developing multifunctional silk-based cartilage and bone bioinks for recreating heterogeneous complicated tissue constructs such

Design of pectin-based bioink containing bioactive agent-loaded microspheres for bioprinting

Bioprinting offers an alternative approach for tissue engineering and exhibits the great potential to play a key role in personalized medicine. One of the major advantages of bioprinting is its capability of achieving the homogeneous distribution of cells within large tissue scaffolds. Microspheres have been used for controlled release of bioactive molecules in tissue engineering. Recently studies show that microspheres,