光热刺激响应性中空介孔碳载体在蛋白多肽类药物皮下精准释药中的研究

It is a key problem to solve the current problems in pharmaceutical research that the construction of the delivery system of protein and polypeptide drugs with low frequency of drug administration, stable long-term drug loading and precise controlled release. Due to the photothermal conversion characteristics of mesoporous carbon in near infrared light which was found in recent researches, our study is proposed to prepare a carbon drug carrier with thermal response properties, based on the grafting of thermosensitive polymer on surface of hollow mesoporous carbon, in order to realize the fixed time, fixed quantity drug release behavior of specific class of biological macromolecules. In this proposal, we select three typical hypoglycemic biological macromolecular drugs, and design a hollow mesoporous carbon nanoparticles to achieve efficient loading and storage stability of macromolecular drugs, with the advantages of macroporous structure and mesoporous structure in drug loading and release. Based on the analysis of the loading and the state of drug in nanoparticles, the structure foundation of this carrier for the high efficiency and stable storage of macromolecular drugs is clarified. In order to find the optimal drug release rule and clarify the mechanism of controlled drug release, the carrier structure characteristics, light triggered conditions and protein structure parameters are observed. The successful implementation of this study is expected to solve the problem such as low loading dosage, poor stability, frequent frequency of delivery, difficult to precisely control the release dose and other issues of macromolecular drugs, the success of this study is to realize the accurate control of intelligent response to drug release of innovative exploration and scientific significance.

构建给药频次少、长期载药稳定且能精准控释的蛋白多肽类药物皮下递送系统是目前药学研究亟需解决的关键问题。鉴于近期发现的介孔碳载体在近红外光照下的光热转换特性，本项目拟通过将温敏聚合物接枝在介孔碳表面，制备具有光热刺激响应性能的碳基药物载体，实现生物大分子药物的定时、定量精准可控释药。研究着眼于三种典型降糖生物大分子药物，综合大孔及介孔结构在载药及释药方面的优势，构建具有特定孔道结构的中空介孔碳纳米粒，实现生物大分子药物的高效装载与稳定储存。通过对载药量、药物状态及活性的分析，阐明该类载体用于大分子药物高效、稳定装载的结构基础；在载体结构特征、光触发条件、蛋白结构参数等不同因素影响下，寻找体系的释药规律，阐明光热刺激响应释药机制。本项目的成功实施有望解决生物大分子药物载药量低、稳定性差、给药次数频繁、释药剂量难以精确控制等问题，为实现药物的智能响应精准控释释药具有创新性的探索和科学的借鉴意义。

为解决胰岛素等降糖类药物需要每日频繁注射给药，不利于长期用药依从性及稳定性的问题，本项目研究开发了光热刺激响应性中空介孔碳载体，以实现降糖药物的皮下刺激响应释药。本项目通过硬模板法获得具备中空内腔及适宜壁厚的中空介孔碳载体（HMCNs），通过不同水热反应温度的调节获得不同比表面积、孔径的HMCNs，能够实现胰岛素及恩格列净等降糖药物的高效装载，并通过XRD、TEM、SEM等评价药物在体系中的存在状态。通过不同聚合比例，合成系列pNIPAM、p(NIPA-AM)、p(NIPA-AL)温敏聚合物，寻找LCST在39-40oC的适宜聚合物p(NIPA-AL17)。以静电吸附层层包附的方法将负电性聚合物PSS、PAA与p(NIPA-AL17)组成多层接枝聚合物，作为体系的释药门控。通过热成像仪绘制HMCNs在不同浓度、不同光密度条件下的升温图谱，HMCNs随着光密度的升高及体系浓度的增大，具有更加显著的升温速率，在808nm的激光照射下，能够迅速实现光热转化，实现从37-40oc的温度转换。采用模型拟合的方法详细研究了光热刺激响应性中空介孔碳纳米体系的释药规律，分别考察载药量、聚合物层数、温度和转数四个因素对1 h 累积释放量，24 h 累积释放量和速率常数 k的影响规律，结果发现聚合物层数及温度为影响最大的两个因素，其中PSS- P(NIPA-AL17)系统中，聚合物层数越多、温度越低时易获得较低的1h释放量和较高的24h释放量；在PAA- P(NIPA-AL17)系统中，聚合物层数多，温度适中的条件则能够获得同样的释药行为。经验证后，模型具有良好的预测性，能够应用于不同聚合物组成的刺激响应性HMCNs释药体系。本项目的成功实施，有望解决生物大分子药物给药次数频繁、释药剂量难以精确控制等问题，为实现降糖药物的智能响应精准控释释药具有创新性的探索和科学的借鉴意义。