壳聚糖纳米硒体系的制备及其物化特性和生物活性的研究

发布时间：2018-01-10 03:07

  本文关键词：壳聚糖纳米硒体系的制备及其物化特性和生物活性的研究　出处：《中国农业大学》2017年博士论文　论文类型：学位论文

  更多相关文章： 硒纳米体系 壳聚糖 物化特性 生物活性 毒性

【摘要】：红色纳米硒元素因其较高的生物活性及低毒性已逐渐成为硒补充领域的研究热点,但其极易转变为黑色或灰色单质硒而失活。为提高红色纳米硒的稳定性,研究者们已尝试采用蛋白质、多糖、多酚、及其他大分子为纳米硒元素的稳定剂或分散剂来制备稳定的硒纳米体系,但目前仍存在着制备耗能、酸性条件易聚集、储存条件苛刻及热不稳定等问题,限制了纳米硒体系作为日常膳食硒制剂的应用。壳聚糖作为来源广泛、生物相容且无毒、耐肠胃酶的天然唯一正电性的多糖已在多功能纳米载体中得到大量的应用探究。本研究采用壳聚糖为稳定剂制备了纳米硒体系,表征并系统分析了其物化属性的精准控制及其相关影响因素,并对该体系进行生物活性和毒性的评价研究;在此基础上为绿色、高效、低毒的纳米硒膳食及经皮补充制剂的制备和应用提供了一定的基础。具体研究结果如下:以分子量分别为3、300KD的壳聚糖(CS)为稳定剂制备的纳米硒体系(CS-SeNps)为均一的红色溶胶,在30天的生长过程中CS(l)-SeNps与CS(h)-SeNps分别以"bottom-up"、"top-down"机制形成粒径约为100nm的"壳-核"或"壳-多核"的球形颗粒。CS(1)-SeNps与CS(h)-SeNps均具有良好的耐pH、耐酶特性及自由基体系控释能力。利用任一不同分子量的壳聚糖(3-600KD)均能制备成粒径均一、可长期稳定贮藏的红色壳聚糖纳米硒体系,其生长机制主要与CS的分子量有关;此外成本低廉的CS-SeNps制备条件为:0.1 mg/mL的CS、2 mM的Se032-及 6 mM的Vc,实际生产时可等比例放大10倍进行小规模试制备。CS-SeNps的介质稳定性与壳聚糖的分子量有关:3KCS-SeNps的pH、离子强度及热稳定性最差,300KCS-SeNps各项稳定性较高;其中3KCS-SeNps适用于酸性的介质,65、300KCS-SeNps在pH=2-10范围内均可应用;三种CS-SeNps在离子强度0-0.4M(pH≈3)的介质中纳米粒度基本可维持在150nm以下,适用性较高;65、300KCS-SeNps具有良好的热稳定性,可应用于不同的热加工工艺,而3KCS-SeNps在80℃条件下具有较高的热稳定性。CS-SeNps在0-10 mg/LHA的介质中具有良好的环境稳定性。该特性与其分子量具有一定的关系:CS-SeNps体系壳聚糖分子量越高,其抗高浓度HA干扰能力越强、但引起其体系粒径和电位发生较大变化所需的HA量则越低。CS-SeNps体系具有良好的体外清除自由基能力,尤其是对ABTS自由基,且30天的生长期有利于提高体系清除自由基的能力;CS-SeNps具有良好的透皮能力、抑制BABLC-3T3和Caco-2细胞系内ROS生成能力、预防UV诱导的皮肤损伤及减缓D-半乳糖诱导小鼠衰老的能力。CS-SeNps的LD50值为H2SeO3的10倍左右,大大降低了其急性毒性。
[Abstract]:Because of its high biological activity and low toxicity, red nano-selenium has become a hot research topic in the field of selenium supplement, but it is easy to be deactivated to black or gray selenium. In order to improve the stability of red nano-selenium. Researchers have tried to use proteins, polysaccharides, polyphenols, and other macromolecules as nano-selenium stabilizers or dispersants to prepare stable selenium nanosystems, but there is still energy consumption. Acidic conditions are easy to gather, storage conditions are harsh and thermal instability, which limits the application of nano-selenium system as daily dietary selenium preparation. Chitosan as a wide range of sources, biocompatibility and non-toxic. Naturally only positively charged polysaccharides resistant to gastrointestinal enzymes have been widely used in multifunctional nano-carriers. In this study, chitosan was used as stabilizer to prepare nano-selenium system. The precise control of its physical and chemical properties and its related influencing factors were characterized and systematically analyzed, and the bioactivity and toxicity of the system were evaluated and studied. On this basis, it provides a certain basis for the preparation and application of green, high-efficient, low-toxic nano-selenium diet and transdermal supplement. The specific results are as follows: the molecular weight is 3. The nanometer selenium system (CS-SeNpss) prepared by using 300KD chitosan as stabilizer is a uniform red sol. During 30 days of growth, CS(l)-SeNps and CS(h)-SeNps were treated with "bottom-up", respectively. The "top-down" mechanism forms spherical particles with a diameter of about 100nm, i.e., "shell-core" or "shell-polynucleus". All of them have good pH tolerance. Using any chitosan with different molecular weight 3-600KD, the red chitosan nano-selenium system can be prepared with uniform particle size and stable storage for a long time. The growth mechanism was mainly related to the molecular weight of CS. In addition, the low cost CS-SeNps preparation conditions are: 1: 0.1 mg/mL CSO 2 mm Se032- and 6 mm VC. In practical production, the medium stability of CS-SeNPS can be enlarged by 10 times in equal proportion. The medium stability of CS-SeNPS is related to the molecular weight of chitosan and the pH value of 0.3KCS-SeNps. The ionic strength and thermal stability of 300KCS-SeNps are the worst. 3KCS-SeNps can be used in the range of pH=2-10 in the acidic medium of 65KCS-SeNps. The nanocrystalline size of CS-SeNps can be kept below 150nm in the medium with ionic strength of 0-0.4Mg pH 鈮，

本文编号：1403587