Gelatin methacryloyl (GelMA) is a versatile biomaterial that has been used in various biomedical fields. Thus far, however, GelMA is mostly obtained from mammalian sources, which are associated with a risk of transmission of diseases, such as mad cow disease, as well as certain religious restrictions. In this study, we synthesized GelMA using fish-derived gelatin by a conventional GelMA synthesis method, and evaluated its physical properties and cell responses. The lower melting point of fish gelatin compared to porcine gelatin allowed larger-scale synthesis of GelMA and enabled hydrogel fabrication at room temperature. The properties (mechanical strength, water swelling degree and degradation rate) of fish GelMA differed from those of porcine GelMA, and could be tuned to suit diverse applications. Cells adhered, proliferated, and formed networks with surrounding cells on fish GelMA, and maintained high initial cell viability. These data suggest that fish GelMA could be utilized in a variety of biomedical fields as a substitute for mammalian-derived materials.

The interest in cultured meat is increasing because of the problems with conventional livestock industry. Recently, many studies related to cultured meat have been conducted, but producing large‐sized cultured meat remains a challenge. It is aimed to introduce 3D bioprinting for producing large cell aggregates for cultured meat production. A hydrogel scaffold is produced at the centimeter scale using a bioink consisting of photocrosslinkable materials for digital light processing‐based (DLP) printing, which has high printing accuracy and can produce geometrically complex structures. The light exposure time for hydrogel photopolymerization by DLP bioprinting is optimized based on photorheometry and cell viability assays. Naturally immortalized bovine embryonic fibroblast cells transformed with MyoD and PPARγ2 instead of primary cells are used as the latter have difficulties in maintaining stemness and are associated with animal ethics issues. The cells are mixed into the hydrogel for printing. Myogenesis and adipogenesis are induced simply by changing the medium after printing. Scaffolds are obtained successfully with living cells and large microchannels. The cooked cultured meat maintains its size and shape upon cutting. The overall dimensions are 3.43 cm × 5.53 cm × 0.96 cm. This study provides proof‐of‐concept for producing 3D cultured meat using bioinks.

To reduce the required capital and time investment in the development of new pharmaceutical agents, there is an urgent need for preclinical drug testing models that are predictive of drug response in human tissues or organs. Despite tremendous advancements and rigorous multistage screening of drug candidates involving computational models, traditional cell culture platforms, animal models and most recently humanized animals, there is still a large deficit in our ability to predict drug response in patient groups and overall attrition rates from phase 1 through phase 4 of clinical studies remain well above 90%. Organ-on-a-chip (OOC) platforms have proven potential in providing tremendous flexibility and robustness in drug screening and development by employing engineering techniques and materials. More importantly, in recent years, there is a clear upward trend in studies that utilize human-induced pluripotent stem cell (hiPSC) to develop personalized tissue or organ models. Additionally, integrated multiple organs on the single chip with increasingly more sophisticated representation of absorption, distribution, metabolism, excretion and toxicity (ADMET) process are being utilized to better understand drug interaction mechanisms in the human body and thus showing great potential to better predict drug efficacy and safety. In this review, we summarize these advances, highlighting studies that took the next step to clinical trials and research areas with the utmost potential and discuss the role of the OOCs in the overall drug discovery process at a preclinical and clinical stage, as well as outline remaining challenges.

The gelatin extracted from mammals of porcine and bovine has been prominently used in pharmaceutical, medical, and cosmetic products. However, there have been some concerns for their usage due to religious, social and cultural objections, and animal-to-human infectious disease. Recently, gelatin from marine by-products has received growing attention as an alternative to mammalian gelatin. In this study, we demonstrate the formation of nanogels (NGs) using fish gelatin methacryloyl (GelMA) and their application possibility to the drug delivery system. The fabrication of fish GelMA NGs is carried out by crosslinking through the photopolymerization of the methacryloyl substituent present in the nanoemulsion droplets, followed by purification and redispersion. There were different characteristics depending on the aqueous phase in the emulsion and the type of solvent used in redispersion. The PBS-NGs/D.W., which was prepared using PBS for the aqueous phase and D.W. for the final dispersion solution, had a desirable particle size (<200 nm), low PdI (0.16), and high drug loading efficiency (77%). Spherical NGs particles were observed without aggregation in TEM images. In vitro release tests of doxorubicin (DOX)-GelMA NGs showed the pH-dependent release behavior of DOX. Also, the MTT experiments demonstrated that DOX-GelMA NGs effectively inhibited cell growth, while only GelMA NGs exhibit higher percentages of cell viability. Therefore, the results suggest that fish GelMA NGs have a potential for nano-carrier as fine individual particles without the aggregation and cytotoxicity to deliver small-molecule drugs.