基于PCL/PLGA共混材料的可降解食管支架：降解速率调控与体外性能分析

Degradable esophageal stent based on PCL/PLGA blend: degradation rate regulation and in vitro performance analysis

摘要

目的：开发一种基于聚己内酯（polycaprolactone，PCL）与聚乳酸-羟基乙酸共聚物[poly（lactic-co-glycolic acid），PLGA]共混材料的可降解食管支架，通过调控PLGA比例（0%~35%）实现降解速率的可控性，平衡力学性能与降解周期，并探索其体外降解特性及临床适配潜力。方法：选择PCL和PLGA用挤出式熔融沉积3D打印技术制备8种梯度共混比例（0%、5%、10%、15%、20%、25%、30%、35% PLGA）食管支架，并结合蜂窝状多孔结构设计（孔隙率60%~70%）。采用人工唾液（pH≈6.6）与人工胃液（pH≈4.0）进行8周的体外降解实验。结果：PLGA比例显著影响降解速率，PLGA比例增加能够加速支架的降解，并且PLGA与PCL共混产生了协同效应（PLGA每增加10%，达到相同失重率的时间缩短50%~70%），PLGA≥25%时导致阶段性崩解现象。pH差异对降解影响不显著（P>0.05），可能因高孔隙设计促进酸产物扩散及PCL疏水性平衡。通过配比调控，降解周期为4~24周。结论：PCL/PLGA共混支架通过简单比例调整，实现降解速率精准调控，产生独特的“支撑-崩解”模式，降低残留风险，满足临床上从先天性狭窄到急性炎症等食管疾病的不同需求。此外，3D打印技术与仿生形态、多孔结构设计相结合，显著提高了支架的组织贴合性和抗移位性。本研究为个性化的可降解食管支架治疗提供了理论依据与技术支持。

Abstract

Objective: This study aimed to develop a biodegradable esophageal stent based on polycaprolactone (PCL) blended with poly (lactic-co-glycolic acid) (PLGA), achieving controllable degradation rates by adjusting the PLGA ratio (0%-35%), balancing mechanical properties and degradation cycles, and exploring its in vitro degradation characteristics and clinical adaptation potential. Methods: PCL and PLGA were selected to prepare eight gradient blend ratios (0%, 5%, 10%, 15%, 20%, 25%, 30%, 35% PLGA) by extrusion-based high-temperature melt rotary 3D printing technology, combined with a honeycomb porous structure design (porosity 60%-70%). In vitro degradation experiments lasting 8 weeks were conducted using artificial saliva (pH≈6.6) and artificial gastric juice (pH≈4.0). Results: The PLGA ratio significantly affected the degradation rate, with increasing PLGA proportion accelerating stent degradation. The blending of PLGA and PCL produced a synergistic effect (for every 10% increase in PLGA, the time to reach the same weight loss rate was shortened by approximately 50%-70%), leading to stage-wise disintegration phenomena (when PLGA≥25%). The pH difference had no significant impact on degradation (P>0.05), possibly due to the high-porosity design promoting diffusion of acidic products and the hydrophobic balance of PCL. Through ratio adjustment, degradation cycles of 4-24 weeks could be achieved. Conclusion: The PCL/PLGA blend stent achieves precise control of degradation rate through simple ratio adjustment, producing a unique “support-disintegration” mode that reduces residual risks and meets clinical needs ranging from congenital strictures to acute inflammation. In addition, the combination of 3D printing technology with biomimetic morphology and porous structure design significantly improves tissue conformity and anti-migration properties of the stent. This study provides theoretical basis and technical support for personalized biodegradable esophageal stent therapy.

关键词

可降解食管支架 / 聚己内酯 / 聚乳酸-羟基乙酸 / 降解速率 / 3D打印

Key words

degradable esophageal stent / polycaprolactone / poly (lactic-co-glycolic acid) / degradation rate / 3D printing

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基金资助

南京市医学科技发展重点项目(ZKX22051)

南京医科大学优秀中青年教师支持计划(南医2022-52)