本文關鍵詞：殼聚糖納米硒體系的制備及其物化特性和生物活性的研究　出處：《中國農(nóng)業(yè)大學》2017年博士論文　論文類型：學位論文

  更多相關文章： 硒納米體系 殼聚糖 物化特性 生物活性 毒性

【摘要】：紅色納米硒元素因其較高的生物活性及低毒性已逐漸成為硒補充領域的研究熱點,但其極易轉(zhuǎn)變?yōu)楹谏蚧疑珕钨|(zhì)硒而失活。為提高紅色納米硒的穩(wěn)定性,研究者們已嘗試采用蛋白質(zhì)、多糖、多酚、及其他大分子為納米硒元素的穩(wěn)定劑或分散劑來制備穩(wěn)定的硒納米體系,但目前仍存在著制備耗能、酸性條件易聚集、儲存條件苛刻及熱不穩(wěn)定等問題,限制了納米硒體系作為日常膳食硒制劑的應用。殼聚糖作為來源廣泛、生物相容且無毒、耐腸胃酶的天然唯一正電性的多糖已在多功能納米載體中得到大量的應用探究。本研究采用殼聚糖為穩(wěn)定劑制備了納米硒體系,表征并系統(tǒng)分析了其物化屬性的精準控制及其相關影響因素,并對該體系進行生物活性和毒性的評價研究;在此基礎上為綠色、高效、低毒的納米硒膳食及經(jīng)皮補充制劑的制備和應用提供了一定的基礎。具體研究結(jié)果如下:以分子量分別為3、300KD的殼聚糖(CS)為穩(wěn)定劑制備的納米硒體系(CS-SeNps)為均一的紅色溶膠,在30天的生長過程中CS(l)-SeNps與CS(h)-SeNps分別以"bottom-up"、"top-down"機制形成粒徑約為100nm的"殼-核"或"殼-多核"的球形顆粒。CS(1)-SeNps與CS(h)-SeNps均具有良好的耐pH、耐酶特性及自由基體系控釋能力。利用任一不同分子量的殼聚糖(3-600KD)均能制備成粒徑均一、可長期穩(wěn)定貯藏的紅色殼聚糖納米硒體系,其生長機制主要與CS的分子量有關;此外成本低廉的CS-SeNps制備條件為:0.1 mg/mL的CS、2 mM的Se032-及 6 mM的Vc,實際生產(chǎn)時可等比例放大10倍進行小規(guī)模試制備。CS-SeNps的介質(zhì)穩(wěn)定性與殼聚糖的分子量有關:3KCS-SeNps的pH、離子強度及熱穩(wěn)定性最差,300KCS-SeNps各項穩(wěn)定性較高;其中3KCS-SeNps適用于酸性的介質(zhì),65、300KCS-SeNps在pH=2-10范圍內(nèi)均可應用;三種CS-SeNps在離子強度0-0.4M(pH≈3)的介質(zhì)中納米粒度基本可維持在150nm以下,適用性較高;65、300KCS-SeNps具有良好的熱穩(wěn)定性,可應用于不同的熱加工工藝,而3KCS-SeNps在80℃條件下具有較高的熱穩(wěn)定性。CS-SeNps在0-10 mg/LHA的介質(zhì)中具有良好的環(huán)境穩(wěn)定性。該特性與其分子量具有一定的關系:CS-SeNps體系殼聚糖分子量越高,其抗高濃度HA干擾能力越強、但引起其體系粒徑和電位發(fā)生較大變化所需的HA量則越低。CS-SeNps體系具有良好的體外清除自由基能力,尤其是對ABTS自由基,且30天的生長期有利于提高體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細胞系內(nèi)ROS生成能力、預防UV誘導的皮膚損傷及減緩D-半乳糖誘導小鼠衰老的能力。CS-SeNps的LD50值為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，

本文編號：1403587