Department of Mechanical and Industrial Engineering, University of Brescia, Via Branze 38, 25133, Brescia, Italy; Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit of Brescia, Via Branze 38, 25133, Brescia, Italy.
Department of Civil Engineering and Architecture, University of Pavia, Via Ferrata 3, 27100, Pavia, Italy; Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit of Pavia, Via Ferrata 3, 27100, Pavia, Italy.
J Mech Behav Biomed Mater. 2021 Dec;124:104814. doi: 10.1016/j.jmbbm.2021.104814. Epub 2021 Sep 8.
The present paper aims at developing an integrated experimental/computational approach towards the design of shape memory devices fabricated by hot-processing with potential for use as gastroretentive drug delivery systems (DDSs) and for personalized therapy if 4D printing is involved. The approach was tested on a plasticized poly(vinyl alcohol) (PVA) of pharmaceutical grade, with a glass transition temperature close to that of the human body (i.e., 37 °C). A comprehensive experimental analysis was conducted in order to fully characterize the PVA thermo-mechanical response as well as to provide the necessary data to calibrate and validate the numerical predictions, based on a thermo-viscoelastic constitutive model, implemented within a finite element framework. Particularly, a thorough thermal, mechanical, and shape memory characterization under different testing conditions and on different sample geometries was first performed. Then, a prototype consisting of an S-shaped device was fabricated, deformed in a temporary compact configuration and tested. Simulation results were compared with the results obtained from shape memory experiments carried out on the prototype. The proposed approach provided useful results and recommendations for the design of PVA-based shape memory DDSs.
本文旨在开发一种综合的实验/计算方法，用于设计通过热加工制造的形状记忆装置，这些装置具有作为胃滞留药物输送系统 (DDS) 的潜力，如果涉及 4D 打印，则可用于个性化治疗。该方法已在药用级增塑聚（乙烯醇）（PVA）上进行了测试，其玻璃化转变温度接近人体温度（即 37°C）。进行了全面的实验分析，以充分表征 PVA 的热机械响应，并提供必要的数据来校准和验证数值预测，这是基于在有限元框架内实现的热粘弹性本构模型。特别是，首先在不同的测试条件和不同的样品几何形状下进行了彻底的热、机械和形状记忆特性研究。然后，制造了一个由 S 形装置组成的原型，将其临时压缩配置变形并进行测试。将模拟结果与在原型上进行的形状记忆实验结果进行了比较。该方法为基于 PVA 的形状记忆 DDS 的设计提供了有用的结果和建议。
