Amaral Vera Lucia Lângaro, Reif Gabriela, Salvador Rafael Alonso, Oliveira Cleiton Alves de, Senn Alfred Paul, Santos Tiago Góss Dos
Universidade do Vale do Itajaí, Itajaí, Santa Catarina, Brazil.
Department of Genetic Medicine and Development, University of Geneva, Geneva, Switzerland.
JBRA Assist Reprod. 2025 Apr 30;29(2):272-81. doi: 10.5935/1518-0557.20240105.
To develop and evaluate the effectiveness of a 3D-printed prototype to hold semen straws during the freezing process under safe and reproducible conditions.
A prototype capable of holding ten straws in liquid nitrogen vapor (LN2) was 3D printed. A second support that is commonly used was assembled from pieces of expanded polyethylene (EPS), respecting the identical distance between the straws and the LN2 surface. Temperatures were registered with a thermocouple placed inside a straw. Semen samples were frozen in the presence of cryoprotectant using the prototype (n=20) and the EPS support (n=20) in two independent series of measurements. Sperm parameters (motility, vitality, and DNA fragmentation) were measured for fresh and frozen-thawed samples.
The temperature cooling curves measured on the prototype were remarkably reproducible. The prototype material withstood over 300 freezing cycles without damage. The mean motility and vitality of fresh (64.2%, 72.0%) and frozen-thawed (25.7%, 38.8%) samples were significantly different (p<0.001) using either support. Recovery rates of motility, vitality, and sperm DNA fragmentation in frozen-thawed sperm samples were equal regardless of straw position on the prototype or support type used.
The developed device allows a homogeneous, quantifiable, reproducible cooling of the straws in liquid nitrogen vapor. The recovery rates are comparable to those reported in the literature for both tested supports. The designed 3-D printed prototype favors the safe handling of the straws, an explicit way of describing freezing conditions, and a better intra-operator and inter-laboratory reproducibility of the cryopreservation process.
开发并评估一种3D打印原型在安全且可重复的条件下，于冷冻过程中固定精液细管的有效性。
3D打印出一种能够在液氮蒸汽（LN2）中固定十根细管的原型。第二个常用的支架由发泡聚乙烯（EPS）碎片组装而成，保持细管与LN2表面之间的距离相同。使用置于细管内的热电偶记录温度。精液样本在冷冻保护剂存在的情况下，分别使用该原型（n = 20）和EPS支架（n = 20），进行两个独立系列的测量来冷冻。对新鲜样本和冻融样本测量精子参数（活力、存活率和DNA片段化）。
在原型上测得的温度冷却曲线具有显著的可重复性。原型材料经受了超过300次冷冻循环而未损坏。使用任何一种支架时，新鲜样本（64.2%，72.0%）和冻融样本（分别为25.7%，38.8%）的平均活力和存活率均存在显著差异（p<0.001）。冻融精子样本中活力、存活率和精子DNA片段化的恢复率，与细管在原型上的位置或所使用的支架类型无关。
所开发的装置可使细管在液氮蒸汽中实现均匀、可量化、可重复的冷却。两种测试支架的恢复率与文献报道相当。设计的3D打印原型有利于安全处理细管，能清晰描述冷冻条件，且在冷冻保存过程中具有更好的操作者内部和实验室间的可重复性。
