Physics-based generative model of curvature sensing peptides; distinguishing sensors from binders

Proteins can specifically bind to curved membranes through curvature-induced hydrophobic lipid packing defects. The chemical diversity among such curvature “sensors” challenges our understanding of how they differ from general membrane “binders” that bind without curvature selectivity. Here, we combine an evolutionary algorithm with coarse-grained molecular dynamics simulations (Evo-MD) to resolve the peptide sequences that optimally recognize the curvature of lipid membranes. We subsequently demonstrate how a synergy between Evo-MD and a neural network (NN) can enhance the identification and discovery of curvature sensing peptides and proteins. To this aim, we benchmark a physics-trained NN model against experimental data and show that we can correctly identify known sensors and binders. We illustrate that sensing and binding are phenomena that lie on the same thermodynamic continuum, with only subtle but explainable differences in membrane binding free energy, consistent with the serendipitous discovery of sensors

The Safe Use of ¹²⁵I-Seeds as a Localization Technique in Breast Cancer during Pregnancy

Introduction: Some aspects of the treatment protocol for breast cancer during pregnancy (PrBC) have not been thoroughly studied. This study provides clarity regarding the safety of the use of 125I-seeds as a localization technique for breast-conserving surgery in patients with PrBC. Methods: To calculate the exposure to the fetus of one 125I-seed implanted in a breast tumor, we developed a model accounting for the decaying 125I-source, time to surgery, and the declining distance between the 125I-seed and the fetus. The primary outcome was the maximum cumulative fetal dose of radiation at consecutive gestational ages (GA). Results: The cumulative fetal dose remains below 1 mSv if a single 125I-seed is implanted at a GA of 26 weeks. After a GA of 26 weeks, the fetal dose can be at a maximum of 11.6 mSv. If surgery takes place within two weeks of implantation from a GA of 26 weeks, and one week above a GA of 32 weeks, the dose remains below 1 mSv. Conclusion: The use of 125I-seeds is safe in PrBC. The maximum fetal exposure remains well below the threshold of 100 mSv, and therefore, does not lead to an increased risk of fetal tissue damage. Still, we propose keeping the fetal dose as low as possible, preferably below 1 mSv