Biofabrication

High failure rates of the current drug development process are driving exemplary changes toward methodologies centered on human disease in-vitro modeling. Organoids are self-organized tissue sub-units resembling their organ of origin and are widely acknowledged for their unique potential in recapitulating human physio-pathological mechanisms. They are transformative for human health by becoming the platform of choice to probe disease mechanisms and advance new therapies. Furthermore, the compounds' validation as therapeutics represents another point of the drug development pipeline where organoids may provide key understandings and help pharma organizations replace or reduce animal research...

Peripheral nerve injuries can lead to sensory or motor deficits that have a serious impact on a patient's mental health and quality of life. Nevertheless, it remains a major clinical challenge to develop functional nerve conduits as an alternative to autologous grafts. We applied reduced graphene oxide (rGO) as a bioactive conductive material to impart electrophysiological properties to the catheter and the application of a pulsed magnetic field to excite the formation of microcurrents and induce nerve regeneration...

Scaffolds play a pivotal role in tissue engineering and serve as vital biological substitutes providing structural support for cell adhesion and subsequent tissue development. An ideal scaffold must possess mechanical properties suitable for tissue function and exhibit biodegradability. Although synthetic polymer scaffolds offer high rigidity and elasticity owing to their reactive side groups, which facilitate tailored mechanical and rheological properties, they may lack biological cues and cause persistent side effects during degradation...

Cancer is one of the leading causes of death in the 21st century with metastasis of cancer attributing to 90% of cancer-related deaths. Therefore, to improve patient outcomes there is a need for better preclinical models to increase the success of translation of oncological therapies into the clinic. Current traditional static in vitro models lack a perfusable network which is critical to overcome the diffusional mass transfer limit to provide a mechanism for the exchange of essential nutrients and waste removal, and increase their physiological relevance...

The anisotropic organization of cells and the extracellular matrix (ECM) is essential for the physiological function of numerous biological tissues, including the myocardium. This organization changes gradually in space and time, during disease progression such as myocardial infarction. The role of mechanical stimuli has been demonstrated to be essential in obtaining, maintaining and de-railing this organization, but the underlying mechanisms are scarcely known. To enable the study of the mechanobiological mechanisms involved, in vitro techniques able to spatiotemporally control the multiscale tissue mechanical environment are thus necessary...

The advent of 3D bioprinting technologies in tissue engineering has unlocked the potential to fabricate in vitro tissue models, overcoming the constraints associated with the shape limitations of preformed scaffolds. However, achieving an accurate mimicry of complex tissue microenvironments, encompassing cellular and biochemical components, and orchestrating their supramolecular assembly to form hierarchical structures while maintaining control over tissue formation, is crucial for gaining deeper insights into tissue repair and regeneration...

Conventional gut-on-chip models typically represent the epithelial layer of the gut tissue, neglecting other important components such as the stromal compartment and the extracellular matrix (ECM) that play crucial roles in maintaining intestinal barrier integrity and function. These models often employ hard, flat porous membranes for cell culture, thus failing to recapitulate the soft environment and complex 3D architecture of the intestinal mucosa. Alternatively, hydrogels have been recently introduced in gut-on-chips as ECM analogs to support the co-culture of intestinal cells in in vivo-like configurations, and thus opening new opportunities in the organ-on-chip field...

The ever-stricter regulations on animal experiments in the field of cosmetic testing have prompted a surge in skin-related research with a special focus on recapitulation of the in vivo skin structure in vitro. In vitro human skin models are seen as an important tool for skin research, which in recent years attracted a lot of attention and effort, with researchers moving from the simplest 2-layered models (dermis with epidermis) to models that incorporate other vital skin structures such as hypodermis, vascular structures, and skin appendages...

With the advent of personalized medicine, the drug delivery system (DDS) will be changed significantly. The development of personalized medicine needs the support of many technologies, among which three-dimensional printing (3DP) technology is a novel formulation-preparing process that creates 3D objects by depositing printing materials layer-by-layer based on the computer-aided design (CAD) method. Compared with traditional pharmaceutical processes, 3DP produces complex drug combinations, personalized dosage, and flexible shape and structure of dosage forms (DFs) on demand...

Tissue engineering has emerged as an advanced strategy to regenerate various tissues using different raw materials, and thus it is desired to develop more approaches to fabricate tissue engineering scaffolds to fit specific yet very useful raw materials such as biodegradable aliphatic polyester like poly(lactide-co-glycolide) (PLGA). Herein, a technique of "wet 3D printing" was developed based on a pneumatic extrusion 3D printer after we introduced a solidification bath into a 3D printing system to fabricate porous scaffolds...

Regenerative healing of spinal cord injury poses an ongoing medical challenge by causing persistent neurological impairment and a significant socioeconomic burden. The complexity of spinal cord tissue presents hurdles to successful regeneration following injury, due to the difficulty of forming a biomimetic structure that faithfully replicates native tissue using conventional tissue engineering scaffolds. 3D bioprinting is a rapidly evolving technology with unmatched potential to create 3D biological tissues with complicated and hierarchical structure and composition...

Spinal cord injury (SCI) could cause permanent impairment to motor or sensory functions. Pre-cultured neural stem cell (NSC) hydrogel scaffolds were demonstrated to be a promising approach to treat SCI with anti-inflammatory effect, axon regrowth and motor function restore. Here in this study, we performed coaxial extrusion process to fabricate a core-shell hydrogel microfiber with high NSC density in the core portion. Oxidized hyaluronic acid (OHA), carboxymethyl chitosan (CMC) and Matrigel blend was used as matrix for NSC growth and to facilitate the fabrication process...

Extrusion-based bioprinting is a promising technology for the fabrication of complex three-dimensional tissue-engineered constructs. To further improve the printing accuracy and provide mechanical support during the printing process, hydrogel-based support bath materials have been developed. However, the gel structure of some support bath materials can be compromised when exposed to certain bioink crosslinking cues, hence their compatibility with bioinks can be limited. In this study, a xanthan gum-based composite support material compatible with multiple crosslinking mechanisms is developed...

High-throughput drug screening is crucial for advancing healthcare through drug discovery. However, a significant limitation arises from available in vitro models using conventional 2D cell culture, which lack the proper phenotypes and architectures observed in 3D tissues. Recent advancements in stem cell biology have facilitated the generation of organoids-3D tissue constructs that mimic human organs in vitro. Kidney organoids, derived from human pluripotent stem cells, represent a significant breakthrough in disease representation...

Polyaniline (PANI) was in-situ polymerized on nanofibrous polycaprolactone mats as cell-free antioxidant cardiac patches (CPs), providing electrical conductivity and antioxidant properties. The fabricated CPs took advantage of intrinsic and additive antioxidant properties in the presence of PANI backbone and ascorbic acid as a biocompatible dopant of PANI. The antioxidant nature of CPs may reduce the serious repercussions of oxidative stress, produced during the ischemia-reperfusion (I/R) process following myocardial infarction...

3D bioprinting has the potential for the rapid and precise engineering of hydrogel constructs that can mimic the structural and optical complexity of a healthy cornea. However, the use of existing light-activated bioinks for corneal printing is limited by their poor cytocompatibility, use of cytotoxic photoinitiators, low photo-crosslinking efficiency, and opaque/colored surface of the printed material. Herein, we report a fast-curable, non-cytotoxic, optically transparent bioprinting system using a new water-soluble benzoyl phosphinate-based photoinitiator and photocrosslinkable methacrylated hyaluronic acid (HAMA)...

The application of additive manufacturing (AM) technology plays a significant role in various fields, incorporating a wide range of cutting-edge technologies such as aerospace, medical treatment, electronic information, and materials. It is currently widely adopted for medical services, national defense, and industrial manufacturing. In recent years, AM has also been extensively employed to produce bone scaffolds and implant materials...

Scaffolds for bone tissue engineering should enable regeneration of bone tissues with its native hierarchically organized ECM and multiple tissue interfaces. To achieve this, inspired by the structure and properties of bone osteon, we fabricated polyhydroxybutyrate-based mineralized electrospun fibrous scaffolds. After studying multiple polyhydroxybutyrate (PHB)-based fibers, we chose 7%PHB/1%Gelatin fibers (PG) to fabricate mineralized fibers that mimic mineralized collagen fibers in bone. The mineralized PG (mPG) surface had a rough, hydrophilic layer of low crystalline calcium phosphate which was biocompatible to BMSCs, induced their proliferation and was osteoinductive...

Cells sense mechanical signals from the surrounding environment and transmit them to the nucleus through mechanotransduction to regulate cellular behavior. Microcontact printing (μCP), which utilizes elastomer stamps, is an effective method for simulating the cellular microenvironment and manipulating cell morphology. However, the conventional fabrication process of silicon masters and elastomer stamps requires complex procedures and specialized equipment, which restricts the widespread application of micropatterning in cell biology and hinders the investigation of the role of cell geometry in regulating cell behavior...

Bioprinting has evolved into a thriving technology for the fabrication of cell-laden scaffolds. Bioinks are the most critical component for bioprinting. Recently, microgels have been introduced as a very promising bioink, enabling cell protection and the control of the cellular microenvironment. However, the fabrication of the bioinks involves the microfluidic production of the microgels, with a subsequent multistep process to obtain the bioink, which so far has limited its application potential. Here we introduce a direct coupling of microfluidics and 3D-printing for the continuous microfluidic production of microgels with direct in-flow printing into stable scaffolds...