Improvement of Antibody Activity by Controlling Its Dynamics Using the Glycan-Lectin Interaction.

Antibody dynamics on membranes, such as endocytosis and clustering, are vital in determining antibody functions. In this study, we demonstrated that glycan conjugation can modulate antibody dynamics through the glycan-lectin interaction to regulate its potency. The anti-HER2 antibody, an anti-breast-cancer antibody, was conjugated with galactose-containing N-glycan, and its internalization was suppressed by interaction with galectin-3, leading to enhanced complement-dependent cytotoxic (CDC) activity. This glycan-antibody conjugate is proposed as a new approach to modulate antibody activity and may provide an alternative strategy for redeveloping antibody drugs that do not exhibit sufficient activity.

Porous nanosheet wrapping for live imaging of suspension cells.

In the field of cell imaging, it is still a practical challenge to obtain the high quality live imaging of suspension cells, mainly due to undesirable cell movement in the imaging field during observation. This study describes a porous nanosheet wrapping method to noninvasively immobilize suspension cells for their live imaging. Perforated nanopores are fabricated on a nanosheet to enable the addition of external chemicals to cells, ranging from small molecules to macromolecules. Through several case studies, such as the live imaging of membrane staining of liposomes, transferrin endocytosis of B cells, and activation of platelets, it is verified that the confined space made by the nanosheet could provide a hydrodynamically stable environment for suspension cells, even if an aqueous stimulus is added through the nanopores in a static or a flowing condition. With this method, the live imaging of the whole activation process on a specific suspension cell in the imaging field is achieved, which is not feasible with the existing cell immobilization methods. This study suggests that the method of porous nanosheet wrapping will facilitate the visualization of the dynamic functions of suspension cells.

Potential of zygotes to produce live births can be identified by the size of the male and female pronuclei just before their membranes break down.

Aim: To determine whether there are differences in size between the male and female pronuclei immediately before the pronuclear membrane breakdown (PNMBD) and to evaluate whether pronuclear size differences influence normal birth rates. Methods: Time-lapse photography was used to measure the size of each pronucleus, while the outcome of 71 frozen-thawed single blastocyst transfers in patients receiving hormone therapy was analyzed retrospectively. The pronuclear measurements were made 4 hours before the PNMBD, corresponding to 16-20 hours after insemination or intracytoplasmic sperm injection, and immediately before the PNMBD. The differences in the areas between the pronuclei in the zygotes that were associated with the live births were compared with those that were associated with the failed pregnancies. Results: The average difference in the area between the pronuclei 4 hours before and immediately before the PNMBD in the patients with a live birth was significantly smaller than in the patients with a failed birth. In addition, the average area difference in the patients with a successful birth was significantly smaller when the measurements were made immediately before the PNMBD, compared with the measurements 4 hours before the PNMBD. Such differences were not detected among the patients who did not achieve a birth. Conclusion: The birth of healthy babies resulted from zygotes that contained pronuclei of similar size when the measurements were made immediately before the PNMBD. Evaluating the size of each pronucleus immediately before the PNMBD provides an effective indicator of the embryo's potential at an early stage of development.