介孔二氧化硅纳米粒的研究进展

介孔二氧化硅纳米粒(MSNs)具有良好生物相容性、有序介孔结构、比表面积大、表面易修饰性等特点,在很多生物医药领域显示出了极大的应用前景,尤其是基于MSNs的纳米药物输送体系被广泛用于各种药物的递送。主要介绍MSNs和可降解MSNs的制备,同时介绍了MSNs膜包被及官能团修饰在缓释控释药物中的应用,最后探讨了MSNs递进到中空介孔二氧化硅纳米粒(HMSNs)的更大的应用前景。     

介孔二氧化硅阿霉素纳米粒的制备及体外释放考察

目的制备载阿霉素的介孔二氧化硅纳米粒(MSN),并对其体外释放进行初步研究。方法通过聚合法制备MSN,应用透射电镜表征纳米粒的形态,动态光散射粒径测定仪测定粒子的平均粒径及分布。紫外可见分光光度法评价载药量、包封率及体外释放。结果纳米粒分布均一,平均粒径约70 nm(PDI<0.1)。药物的载药量和包封率分别为(20.38±3.58)%和(55.29±5.17)%。纳米粒经24 h恒温振荡释放达平衡,在pH 5.5磷酸盐缓冲液中累积释放分数达到95%。结论 MSN具有较高的药物载药量,有望成为一种新型的化疗药物载体。     

不同载药方法对介孔二氧化钛纳米粒载药及药物溶出速率的影响

目的考察不同载药方法对介孔二氧化钛纳米粒载药系统载药和溶出速率的影响。方法通过溶剂挥干法、熔融法、吸附平衡法分别将卡维地洛包载于介孔二氧化钛纳米粒中,用扫描电镜和透射电镜观测样品形貌,氮气吸附-解吸法测量载体的比表面积和孔体积,差示扫描量热法分析药物粒子的存在状态,X-射线衍射法进行物相分析,热失重法分析载药量,最后测定载药系统的溶出速率并进行长期稳定性试验。结果三种载药方法均能通过改变药物的存在状态使药物以非晶型存在于载体中而达到提高溶出速率的目的。其中溶剂挥干法所得的载药系统溶出速率提高显著,并且更具有长期稳定性。结论溶剂挥干法为介孔二氧化钛纳米粒载药的首选。     

载阿霉素介孔二氧化硅纳米粒的细胞毒性及细胞摄取

目的制备载阿霉素的介孔二氧化硅纳米粒(mesoporous silica nanoparticles,MSN),对其理化性质及细胞摄取行为进行初步研究。方法通过聚合法制备MSN,透射电镜表征纳米粒的形态,动态光散射粒径测定仪测定粒子的平均粒径及分布。紫外分光光度计测定阿霉素的负载行为,MTT比色分析法研究粒子的细胞毒性,激光共聚焦显微镜观察其人乳腺癌MCF-7细胞对载药粒子的摄取。结果纳米粒分布均一,平均粒径约70 nm(PDI<0.1),载药量质量分数达到20%。MCF-7细胞对载药粒子的摄取较快,空白纳米粒具有较低的细胞毒性。结论介孔二氧化硅纳米粒具有较高的药物载药量和良好的生物相容性,能较快地被对人乳腺癌MCF-7细胞摄取,有望成为一种新型的药物化疗载体。     

介孔二氧化硅纳米粒增溶型非诺贝特片剂的制备及体内外研究

目的 制备介孔二氧化硅纳米粒(mesoporous silica nanoparticles,HK)增溶型非诺贝特(fenofibrate,FNB)片剂并进行体内外研究。方法 用吸附法以HK为FNB的载体制成固体分散体(FNB-HK)。采用差示扫描量热法、X射线衍射法和傅里叶红外光谱法分析非诺贝特在FNB-HK中的存在状态。通过考察体外溶出度,优化处方并制片。将自制片和市售片分别对家兔单剂量口服给药,采用高效液相色谱法测定家兔血浆药物浓度。结果 FNB-HK表征表明HK能够抑制非诺贝特的结晶。经过处方优化,乳糖做填充剂,8%羧甲基淀粉钠为崩解剂时,片剂能够达到最理想的溶出速率。自制片与市售片相比,体内达峰时间提前,达峰浓度增大,相对生物利用度为149.95%。结论 本研究研制的片剂能显著改善FNB的溶出速率,提高其口服生物利用度。     

有序介孔硅胶提高难溶性药物白藜芦醇的溶出速率

本研究的目的是制备有序介孔硅胶并考察其作为难溶性药物载体的体外药物释放特点。以十六烷基三甲基溴化铵为模板合成了有序介孔硅胶, 以白藜芦醇为模型药物, 采用扫描电镜、透射电镜、N₂吸附-脱附、X-射线衍射和红外光谱对载药前后的有序介孔硅胶进行表征, 并考察药物体外释放行为。结果表明, 合成的有序介孔硅胶比表面积大、粒度均匀, 具有有序六方孔道结构, 载药后药物以无定形态或分子态存在, 释放速率明显提高。有序介孔硅胶有望成为新型的难溶性药物载体。     

介孔二氧化硅和中空介孔二氧化硅载体用于提高难溶性药物溶出度的比较

目的研究介孔二氧化硅(mesoporous silica nanoparticles,MSN)和中空介孔二氧化硅(hollow mesoporous silica nanoparticles,HMSN)两种载体对提高难溶性药物缬沙坦(valsartan,VAL)和尼莫地平(nimodipine,NMP)的载药量以及改善药物溶出度作用的比较。方法采用溶剂挥干法制备VAL-MSN、VAL-HMSN、NMP-MSN和NMP-HMSN四种固体分散体,以紫外分光光度法测定样品的载药量。采用X射线衍射法表征药物的存在状态。以溶出度为评价指标,对原料药、无定型药物以及载药体系的溶出速率进行了比较。结果 VAL-HMSN和NMP-HMSN的载药量分别为(34.76±1.36)%和(38.30±1.38)%,而VAL-MSN和NMP-MSN的载药量分别为(23.54±1.72)%和(22.93±1.08)%。X射线衍射实验表明药物在载体中以非晶体状态存在。溶出实验结果显示无定型药物的溶出度最低,HMSN和MSN载药体系的溶出度均比原料药有所提高。结论 HMSN和MSN相比,HMSN载药体系的载药量更高,但溶出度较MSN载药体系低。     

白屈菜红碱介孔二氧化硅纳米粒缓释片的制备及体外释药考察

目的：制备白屈菜红碱介孔二氧化硅纳米粒缓释片（CHE-MSNs-SRTs）,并进行体外释药考察。方法：溶剂挥发法制备CHE-MSNs,测定包封率、载药量、粒径、Zeta电位,扫描电镜观察微观形态,X射线粉末衍射法分析晶型。羟丙基甲基纤维素为骨架材料制备CHE-MSNs-SRTs。单因素考察结合Box-Behnken响应面法优化CHE-MSNs-SRTs处方,对释药模型和释药机理进行探讨。结果：CHE-MSNs平均包封率为（93.58±1.17）%,载药量为（23.15±0.72）%,粒径为（223.7±9.24)nm,Zeta电位为（0.74±0.06)mV,纳米粒呈球形或类球形,白屈菜红碱以无定型状态存在于CHE-MSNs中。CHE-MSNsSRTs最佳处方为：HPMC 4K和HPMC 15K比例为1.9∶1,缓释材料用量为17.8 mg/片,PEG用量为10.6 mg/片,缓释特征明显,12 h累积释放度为93.68%。体外释药符合Higuchi模型,释药机制为扩散和骨架溶蚀并存。结论：CHE-MSNs-SRTs工艺重复性良好,体外释药缓释特征明显。     

介孔硅材料提高难溶性药物生物利用度的研究进展

介孔二氧化硅作为近年来比较热门的无机介孔载体材料,因其具有孔道排列规整、水热稳定性良好、生物相容性好,可以储存药物并保持药物的无定形态等特点,非常适合装载水难溶性药物。本文通过查阅国内外的相关文献,就难溶性药物口服生物利用度低的原因进行分析,并归纳总结了国内外关于介孔二氧化硅载体提高难溶性药物生物利用度方面的最新研究进展,为设计和制备具有特定结构和性能的介孔二氧化硅载体,提高难溶性药物的生物利用度及其临床应用提供参考。     

Capped mesoporous silica nanoparticles as stimuli-responsive controlled release systems for intracellular drug/gene delivery

Importance of the field: The incorporation of stimuli-responsive properties into nanostructured systems has recently attracted significant attention in the research of intracellular drug/gene delivery. In particular, numerous surface-functionalized, end-capped mesoporous silica nanoparticle (MSN) materials have been designed as efficient stimuli-responsive controlled release systems with the advantageous ‘zero premature release’ property.

Areas covered in this review: Herein, the most recent research progress on the design of biocompatible, capped MSN materials for stimuli-responsive intracellular controlled release of therapeutics and genes is reviewed. A series of hard and soft caps for drug encapsulation and a variety of internal and external stimuli for controlled release of different cargoes are summarized. Recent investigations on the biocompatibility of MSN both in vitro and in vivo are also discussed.

What the reader will gain: The reader will gain an understanding of the challenges for the future exploration of biocompatible stimuli-responsive MSN devices.

Take home message: With a better understanding of the unique features of capped MSN and its behaviors in biological environment, these multifunctional materials will find a wide variety of applications in the field of drug/gene delivery.     

Evaluation of mesoporous silica particles as drug carriers in hydrogels

Mesoporous silica particles have recently been used in the preparation of solid oral as well as dermal pharmaceutical formulations. In this work, the use of mesoporous silica of different particle size, pore size and pore volume as carrier for curcumin in hydrogels for dermal use was investigated. Oil absorption capacity of the silica, in vitro release of curcumin from formulations and chemical stability of curcumin during three months storage were evaluated. It was found that the silica particles did not alter in vitro release of curcumin compared to an emulsion. Furthermore, curcumin was found to exhibit similar or inferior stability in hydrogels containing mesoporous silica opposed to emulsions.     

A comparison of mesoporous silica nanoparticles and mesoporous organosilica nanoparticles as drug vehicles for cancer therapy

Mesoporous silica nanoparticles (MSNs) are promising drug carriers for use in cancer treatment owing to their excellent biocompatibility and drug‐loading capacity. However, MSN's incomplete drug release and toxic bioaccumulation phenomena limit their clinical application. Recently, researchers have presented redox responsive mesoporous organosilica nanoparticles containing disulfide (S–S) bridges (ss‐MONs). These nanoparticles retained their ability to undergo structural degradation and increased their local release activity when exposed to reducing agents. Disulfide‐based mesoporous organosilica nanoparticles offer researchers a better option for loading chemotherapeutic drugs due to their effective biodegradability through the reduction of glutathione. Although the potential of ss‐MONs in cancer theranostics has been studied, few researchers have systematically compared ss‐MONs with MSNs with regard to endocytosis, drug release, cytotoxicity, and therapeutic effect. In this work, ss‐MONs and MSNs with equal morphology and size were designed and used to payload doxorubicin hydrochloride (DOX) for liver cancer chemotherapy. The ss‐MONs showed considerable degradability in the presence of glutathione and performed comparably to MSNs on biocompatibility measures, including cytotoxicity and endocytosis, as well as in drug‐loading capacity. Notably, DOX‐loaded ss‐MONs exhibited higher intracellular drug release in cancer cells and better anticancer effects in comparison with DOX‐loaded MSNs. Hence, the ss‐MONs may be more desirable carriers for a highly efficient and safe treatment of cancer.     

单分散性介孔二氧化硅的制备及靶向性评价

目的：为了制备可稳定分散的介孔二氧化硅纳米材料，并将其用于尾静脉注射的纳米制剂。方法：本文采用Stober法，以十六烷基三甲基溴化铵（CTAB）为模板剂，正硅酸乙酯（TEOS）为硅源，通过酸液萃取法去除模板，制备出分散性良好的MSN纳米粒。通过FTIR、扫描电子显微镜及透射电镜等仪器，进行结构和形貌的表征。结果：单因素实验结果可知MSN的最佳制备工艺为：CTAB/TEOS质量比为1：5，pH 10，反应温度70~80℃，搅拌速率为500 r·min^-1。MSN负载DOX，表现出高负载率；体外释放实验表明DOX在中性条件下释放缓慢，弱酸性条件下释放迅速；体内实验表明MSN具有良好的靶向性。结论：通过优化后的制备工艺，MSN可稳定分散，该制剂制备方法简单，具有pH敏感性，良好的靶向性，有利于达到肿瘤靶向给药的要求，介孔二氧化硅在靶向传递系统的应用具有广阔前景。     

稀释剂对HPMC骨架片释药的影响

目的　探讨稀释剂对难溶性药物的HPMC骨架片释药的影响。方法　以甲氧苄胺嘧啶、卡马西平、磺胺甲 口 恶 唑和茶碱四种难溶型性药物为模型药物 ,测定三种相同剂量的稀释剂 (糊精、乳糖和磷酸氢钙 )时药物的释放度。结果　甲氧苄胺嘧啶、卡马西平、磺胺甲 口恶 唑的释药速率为糊精 >乳糖 >磷酸氢钙 ;而茶碱的释药速率为糊精≈乳糖 >磷酸氢钙。结论　稀释剂对难溶性药物HPMC骨架片释药的影响同药物HPMC骨架片的释药机制有关     

Mesoporous silica nanoparticles as controlled release drug delivery and gene transfection carriers

In this review, we highlight the recent research developments of a series of surface-functionalized mesoporous silica nanoparticle (MSN) materials as efficient drug delivery carriers. The synthesis of this type of MSN materials is described along with the current methods for controlling the structural properties and chemical functionalization for biotechnological and biomedical applications. We summarized the advantages of using MSN for several drug delivery applications. The recent investigations of the biocompatibility of MSN in vitro are discussed. We also describe the exciting progress on using MSN to penetrate various cell membranes in animal and plant cells. The novel concept of gatekeeping is introduced and applied to the design of a variety of stimuli-responsive nanodevices. We envision that these MSN-based systems have a great potential for a variety of drug delivery applications, such as the site-specific delivery and intracellular controlled release of drugs, genes, and other therapeutic agents.     

Development of phosphonate-terminated magnetic mesoporous silica nanoparticles for pH-controlled release of doxorubicin and improved tumor accumulation

In this study, phosphonate-terminated magnetic mesoporous nanoparticles (pMMSNs) was designed by incorporation of MNPs in the center of mesoporous silica nanoparticles (MSNs) and followed by grafting phosphonate group on to the surface of MMSNs. The carrier exhibited a typical superparamagnetic feature and the saturation magnetization was 4.89 emu/g measured by vibrating sample magnetometer (VSM). pMMSNs had a spherical morphology and a pore size of 2.2 nm. From N₂ adsorption-desorption analysis, pMMSNs had a surface area of 613.4 m²/g and a pore volume of 0.78 cm³/g. Phosphonate modification improved the colloidal stability of MMSNs, and the hydrodynamic diameter of pMMSNs was around 175 nm. The hydrophilic phosphonate group significantly enhanced the negative surface charge of MMSNs from −19.3 mV to −28.8 mV pMMSNs with more negative surface charge had a 2.3-fold higher drug loading capacity than that of MMSNs. In addition, the rate and amount of release of doxorubicin (DOX) from DOX/pMMSNs was pH-dependent and increased with the decrease of pH. At pH 7.4, the release amount was quite low and only approximately 17 wt% of DOX was released in 48 h. At pH 5.0 and 3.0, the release rate increased significantly and the release amount achieved 31 wt% and 60 wt% in 48 h, respectively. To evaluate the magnetic targeting performance of pMMSNs, FITC labeled pMMSNs was injected into mice bearing S180 solid tumor. FITC labeled pMMSNs controlled by an external magnetic field showed higher tumor accumulation and lower normal tissue distribution.     

介孔二氧化硅纳米粒的制备及对载药与药物溶出度的影响

目的为提高水难溶性药物的分散性及溶出度,制备介孔二氧化硅纳米粒作为水难溶性药物的载体。方法探索得到简单有效地制备球状介孔二氧化硅纳米粒的工艺条件,采用扫描电镜及氮气吸附-脱附等手段分析表征载体的外观形貌,比表面积及孔径分布,并选取水难溶性药物西洛他唑作为模型药物,以溶剂浸渍挥干法载药制得药物固体分散体,采用热分析、氮气吸附-脱附曲线以及溶出度实验研究药物固体分散体的基本性质。结果制得的二氧化硅载体的形貌近球状,粒径大小分布在200～250 nm,载体的比表面积最高可达1 101.54 m2.g-1,孔径分布主要集中在3.0～4.0 nm。载药过程对西洛他唑在载体中的存在形式没有影响,固体分散体中西洛他唑的溶出度得到显著提高,当药物与载体的质量比为1∶3时,药物60 min累计溶出达85%。结论介孔二氧化硅纳米粒有望成为水难溶性药物的优良载体。