Aim
The uptake pathway of liposomes into cells is mainly via endocytosis or membrane fusion; however, the relationship between the uptake pathway and the intracellular pharmacokinetics of the liposome components remains unclear. This study aimed at revealing the relationship by using cationic liposomes having similar physical properties and different uptake pathways.
Materials and Methods
We prepared cationic liposomes composed of amino acid-type lipids, K3C14 and K3C16, which have different uptake pathways by a hydration method, and fluorescently modified them by encapsulating FITC-dextran and surface conjugation with Alexa Fluor
®
488 (AF488). Then, we investigated their intracellular distribution in HeLa cells over time.
Results
The liposomes had similar physical properties and did not cause significant cell mortality after treatment for 180 min. The delivery rate and efficiency of encapsulated FITC-dextran with the fusogenic K3C16 liposomes were 3 and 1.6 times higher, respectively, than with the endocytic K3C14 liposomes. FITC-dextran molecules delivered with K3C16 liposomes were observed throughout the cytosolic space after 10 min, while those delivered with K3C14 liposomes were mainly observed as foci and took 60 min to diffuse into the cytosolic space. K3C14 lipids modified with AF488 were distributed mostly in the cytosolic space. In contrast, fluorescently labeled K3C16 lipids were colocalized with the plasma membrane of 50% of the HeLa cells after 10 min and were gradually internalized intracellularly.
Conclusion
Fusogenic K3C16 liposomes internalized into HeLa cells faster than endocytic K3C14 liposomes, and their components differently distributed in the cells.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2),
which
is the etiological agent of coronavirus disease 2019 (COVID-19), has
infected more than 340 million people since the outbreak of the pandemic
in 2019, resulting in approximately 55 million deaths. The rapid and
effective diagnosis of COVID-19 patients is vital to prevent the spread
of the disease. In a previous study, we reported a novel temperature-responsive
liposome-linked immunosorbent assay (TLip-LISA) using biotinylated-TLip
that exhibited high detection sensitivity for the prostate-specific
antigen. Herein, we used immunoglobulin-TLip (IgG-TLip), in which
the antibodies were directly conjugated to the liposomal surface to
simplify pretreatment procedures and reduce the detection time for
SARS-CoV-2. The results indicated that TLip-LISA could detect the
recombinant nucleocapsid protein and the nucleocapsid protein in inactivated
virus with 20 min incubation time in total, and the limit of detection
was calculated to be 2.2 and 1.0 pg/mL, respectively. Therefore, TLip-LISA
has high potential to be used in clinic for rapid diagnosis and disease
control.
SummaryPrevious commentary systems generate commentaries only from the viewpoint of a commentator. However there are various viewpoints for comments, and such different viewpoints invoke various comments. The amount of information about a situation may differ between the viewpoints, and the understandings of the situation may also differ between them. In this paper, we propose a method to generate commentaries automatically so that users can easily understand situations by taking into account the different understandings of the situations between viewpoints. Our method is composed of two parts. The first is generation of comment candidates about the current situation, unexpected actions, intentions of players by using a game tree. The second is comment selection which chooses comments related to the prior one so that listeners can compare the situations from different viewpoints. Based on our approach, we implemented an experimental system that generates commentaries on mahjong games. We discuss the output of the system.
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