BACKGROUND: Three-dimensional (3D) printing using hydrogel has made great strides when it comes to mimicking 3Dartificial tissue in the medical field. However, most structures do not mimic the dynamic movement of the tissues. Withoutimitating dynamic movements, there are limitations on the extent to which the proper implementation of the tissue’s ownfunctions can be achieved.METHOD: In this study, we intend to present an approach to solving this problem using hydroxybutyl methacrylatedchitosan (HBC-MA), a photo-crosslinkable/temperature reversible chitosan polymer. In addition, stereolithography-3D(SLA-3D) printing technology was used, which is more likely to mimic the complex microstructure. As a control, a 3Dstructure made with pristine poly(ethylene glycol) dimethacrylate (PEG-DMA) was created, and a 4D structure wasprepared by adding HBC-MA to poly(ethylene glycol) dimethacrylate (PEG-DMAP) resin. RESULTS: HBC-MA caused the expansion of water into the polymer matrix at low temperature, and the 4D structureresulted in expansion of the polymer volume, generating dynamic movement due to the expansion of water. Conversely, asthe temperature rose, deswelling occurred, followed by a decrease in the volume, showing a shape memory property ofreturning to the existing structure. Morphological, swelling, and mechanical analysis further confirmed the principle ofdynamic movement. In addition, parameters were provided through calculation of the bending ratio angle (h). CONCLUSION Through this, it is suggested that HBC-MA can be applied as a core polymer for SLA-4D printing, andhas high potential for realizing the dynamic movement of tissue.

BACKGROUND: Three-dimensional (3D) printing using hydrogel has made great strides when it comes to mimicking 3Dartificial tissue in the medical field. However, most structures do not mimic the dynamic movement of the tissues. Withoutimitating dynamic movements, there are limitations on the extent to which the proper implementation of the tissue’s ownfunctions can be achieved.METHOD: In this study, we intend to present an approach to solving this problem using hydroxybutyl methacrylatedchitosan (HBC-MA), a photo-crosslinkable/temperature reversible chitosan polymer. In addition, stereolithography-3D(SLA-3D) printing technology was used, which is more likely to mimic the complex microstructure. As a control, a 3Dstructure made with pristine poly(ethylene glycol) dimethacrylate (PEG-DMA) was created, and a 4D structure wasprepared by adding HBC-MA to poly(ethylene glycol) dimethacrylate (PEG-DMAP) resin. RESULTS: HBC-MA caused the expansion of water into the polymer matrix at low temperature, and the 4D structureresulted in expansion of the polymer volume, generating dynamic movement due to the expansion of water. Conversely, asthe temperature rose, deswelling occurred, followed by a decrease in the volume, showing a shape memory property ofreturning to the existing structure. Morphological, swelling, and mechanical analysis further confirmed the principle ofdynamic movement. In addition, parameters were provided through calculation of the bending ratio angle (h). CONCLUSION Through this, it is suggested that HBC-MA can be applied as a core polymer for SLA-4D printing, andhas high potential for realizing the dynamic movement of tissue.

Background and Objectives: MYC, also known as an oncogenic reprogramming factor, is a multifunctional transcription factor that maintains induced pluripotent stem cells (iPSCs). Although MYC is frequently upregulated in various cancers and is correlated with a poor prognosis, MYC is downregulated and correlated with a good prognosis in lung adenocarcinoma. MYC and two other MYC family genes, MYCN and MYCL, have similar structures and could contribute to tumorigenic conversion both in vitro and in vivo. Methods: and Results: We systematically investigated whether MYC family genes act as prognostic factors in various human cancers. We first evaluated alterations in the expression of MYC family genes in various cancers using the Oncomine and The Cancer Genome Atlas (TCGA) database and their mutation and copy number alterations using the TCGA database with cBioPortal. Then, we investigated the association between the expression of MYC family genes and the prognosis of cancer patients using various prognosis databases. Multivariate analysis also confirmed that co-expression of MYC/MYCL/MYCN was significantly associated with the prognosis of lung, gastric, liver, and breast cancers. Conclusions Taken together, our results demonstrate that the MYC family can function not only as an oncogene but also as a tumor suppressor gene in various cancers, which could be used to develop a novel approach to cancer treatment.