de Wolf Johanna R, Paulusse Jos M J, Bosschaart Nienke
Department of Biomedical Photonic Imaging, Faculty of Science and Technology, University of Twente, P.O. Box 217, Enschede, 7500 AE, The Netherlands.
Department of Molecules and Materials, Faculty of Science and Technology, University of Twente, P.O. Box 217, Enschede, 7500 AE, The Netherlands.
Sci Rep. 2025 Apr 3;15(1):11500. doi: 10.1038/s41598-025-95733-0.
Research into human milk often involves freezing, thawing and diluting. However, these steps influence the integrity of native milk particles, such as casein micelles (CMs) and extracellular vesicles (EVs). Correct sample preparation is vital for research into these particles, but validated protocols are scarce in the literature. Here, we design, synthesise and evaluate a novel medium for dilution: simulated human milk ultrafiltrate (SHMUF), aimed to preserve particle integrity. We evaluate the stability of fresh and frozen/thawed human milk in SHMUF, bovine simulated milk ultrafiltrate (SMUF), phosphate buffered saline (PBS) and demineralised water through changes in light scattering in optical transmission. Light scattering by human milk diluted with SHMUF remains stable for 10 h, whereas substantial changes are observed for milk samples diluted with the other media. Likewise, freezing and thawing cause changes in light scattering. We conclude that SHMUF most optimally preserves native particles, and that - ideally - freezing and thawing should be avoided.
对母乳的研究通常涉及冷冻、解冻和稀释。然而，这些步骤会影响天然乳汁颗粒的完整性，如酪蛋白胶束（CMs）和细胞外囊泡（EVs）。正确的样品制备对于这些颗粒的研究至关重要，但文献中缺乏经过验证的方案。在此，我们设计、合成并评估了一种新型稀释介质：模拟人乳超滤液（SHMUF），旨在保持颗粒完整性。我们通过光透射中光散射的变化，评估了新鲜和冷冻/解冻母乳在SHMUF、牛模拟乳超滤液（SMUF）、磷酸盐缓冲盐水（PBS）和去离子水中的稳定性。用SHMUF稀释的母乳的光散射在10小时内保持稳定，而用其他介质稀释的乳汁样品则观察到显著变化。同样，冷冻和解冻也会导致光散射的变化。我们得出结论，SHMUF能最优化地保存天然颗粒，并且理想情况下应避免冷冻和解冻。
