Vitrimers are covalently crosslinked networks with dynamic bond exchange, where their dynamic behavior is typically regulated by adjusting network structures or incorporating fillers. This study introduces graphite flakes (GFs) into sulfur-containing. Vitrimers to investigate their effects on mechanical properties, stress relaxation, and thermal conductivity. The results demonstrate that adding 10 wt.% GFs increases tensile strength by 4.37% compared to pure epoxy vitrimer, while higher filler content reduces toughness and decelerates stress relaxation. At 160 °C, the characteristic relaxation time rises from 15.35 s (pure vitrimer) to 108.85 s (40 wt% GFs composite). The Arrhenius prefactor ( τ₀ ) decreases with GFs loading, whereas the activation energy ( E a ) remains nearly unaffected. Additionally, 40 wt.% GFs enhance thermal diffusivity by 110.17% due to oriented phonon transport channels. Chemical recycling via DTT solution achieves complete matrix degradation and filler recovery without damaging GFs. This study provided valuable insights for optimizing vitrimer composites, particularly in enhancing thermal conductivity and modulating dynamic properties.
Ya Wen,Yiqiong Liu,Fangfang Guo,Yi Han,Qiansai Qiu,Yan Li,Haiqing Dong,Tianbin Ren,Yongyong Li
It has been suggested that immunogenic cell death (ICD) has therapeutic potential; however, its anticancer immunity is considerably hampered by the in situ immunosuppressive microenvironment within the tumor area, such as the dysfunction of antigen-presenting cells. Herein, we present an in vitro ICD-inducing modality to circumvent such impairment of immune activation. To this end, a “hot”, i.e., immunogenic, whole tumor cell vaccine is generated in vitro and subcutaneously vaccinated in the normal tissue, departing from the site of the in situ immunosuppressive tumor area, to fully leverage the ICD-inducing antitumor immunity. In particular, the immunogenic dying tumor cells, caged by cellular disulfide–thiol exchange, are mediated by photoactivation. After subcutaneous vaccination, the photoactivated caged live cell vaccine (CLCV) exerts multi-durable immunostimulatory property, which, when adjuvanted by CpG, efficiently promotes dendritic cell (DC) activation and elicits robust CD8+ T-cell responses in vivo. Importantly, the generated T-cell responses are shown to protect 75% mice preimmunized with CLCV against tumor initiation and significantly retards tumor growth in the therapeutic setting. The strategy presented here may help to enrich the current vaccine design for cancer immunotherapy.
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