共查询到20条相似文献,搜索用时 15 毫秒
1.
通过化学交联法合成组氨酸修饰透明质酸耦合物(His-HA),制备载阿霉素纳米粒,分析其pH值响应性和抗肿瘤特征.研究显示,随着pH值的降低(7.4~5.5),纳米粒的粒径增大(230~780nm),zeta电位升高,载药纳米粒的体外释放量增加.细胞毒性实验显示粒径<300nm的载药纳米粒具更高的毒性.细胞摄入实验表明,阿霉素通过受体介导的胞吞和载药纳米粒的胞外释放两种途径被细胞摄入.以上研究显示组氨酸修饰透明质酸纳米粒具有显著的pH值响应性,具备作为阿霉素药物载体的应用前景. 相似文献
2.
Yung Priscilla Lai Zhaoxin Li Hani Naguib Eric Diller 《Advanced Engineering Materials》2023,25(20):2301060
Limited space on millimeter-scale devices for biomedical applications makes it challenging to incorporate bulky actuators and power for onboard mechanical actuation. Stimuli-responsive hydrogels, such as pH-responsive hydrogels, provide a solution to automatically sense and actuate in the gastrointestinal tract. However, hydrogels are often nonload bearing and slow in actuation. To overcome these challenges, a new type of hybrid actuator is developed which utilizes a pH-responsive hydrogel with magnets to trigger magnetic springs (i.e., permanent magnets with repulsive, spring-like forces) to quickly initiate rotational and translational movements at pH > 6. The agar-poly(acrylic acid) hydrogel undergoes a large volume transition at pH > 6 and exhibits large nominal blocking stress of 610–819 kPa for a 3–4 mm diameter cylinder hydrogel. Moreover, the scaling of hydrogel force and response times are experimentally confirmed. Based on the hydrogel properties, an analytical hydrogel model is developed to predict hydrogel force and displacement under varying magnetic loads and wall constraints in simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 6.8), and the experimental data validate the model. Finally, an innovative hybrid hydrogel-magnet actuator that triggers rotational and translational motion without external activation is demonstrated. 相似文献
3.
刺激响应性分离膜的制备及研究是近年来的热点,其在生物传感器、选择性分离、药物可控释放等领域具有广阔的应用前景。文中综述了等离子处理引发接枝,紫外光引发接枝,化学热引发接枝和可控活性接枝等四种主要的接枝方法在高分子分离膜表面的接枝改性研究进展,主要围绕具有刺激响应性功能的分离膜的制备研究进行介绍,对存在的问题进行了讨论,并阐述了刺激响应性分离膜的发展方向。 相似文献
4.
Ana Arizaga Gemma Ibarz Rafael Piñol Ainhoa Urtizberea 《Journal of Experimental Nanoscience》2014,9(6):561-569
A multiresponsive system that consists on pH-responsive polymer microspheres with encapsulated iron oxide magnetic nanoparticles that rendered the core magnetic to enable externally controlled actuation under magnetic induction has been developed. The inorganic nanoparticles were first prepared and, then, further encapsulated in a pH-sensitive poly(4-vinylpyridine). These spheres have been obtained by a modification of the simple, rapid and high-reproducible nanoprecipitation method. Magnetic measurements showed that the iron oxide nanoparticles are superparamagnetic and, therefore, able to undergo a local increase of the temperature when an oscillating magnetic field is applied. Magnetically triggered heating and pH sensitivity can be useful for biomedical applications. 相似文献
5.
首先研究了液-液静态界面聚合反应界面处的pH值与反应时间的关系,然后以聚甲基丙烯酸N,N-二甲氨基乙酯(PDM AEM A)作为交联预聚物,利用双苄基试剂进行季铵化反应,在聚砜基膜表面固载PDM AEM A凝胶层,制得荷正电的复合纳滤膜。研究了pH值与凝胶层溶胀度和复合膜分离性能的关系。实验表明,界面聚合产生的季铵盐有两相相容性,在反应中起到自催化作用;此膜面界面聚合在特定的pH值范围才能得到性能良好的纳滤膜;PDM AEM A水凝胶层随pH值的变化溶胀度有明显变化;所制得的复合纳滤膜具有pH敏感性。 相似文献
6.
Yinmei Tian;Qian Hu;Zhengjun Sun;Yulin Yu;Xiaonan Li;Tianyi Tian;Xinying Bi;Yang Li;Boning Niu;Zhiping Zhang; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(33):2311890
Ulcerative colitis (UC), an immune-mediated chronic inflammatory disease, drastically impacts patients' quality of life and increases their risk of colorectal cancer worldwide. However, effective oral targeted delivery and retention of drugs in colonic lesions are still great challenges in the treatment of UC. Coacervate microdroplets, formed by liquid–liquid phase separation, are recently explored in drug delivery as the simplicity in fabrication, spontaneous enrichment on small molecules and biological macromolecules, and high drug loading capacity. Herein, in this study, a biocompatible diethylaminoethyl-dextran hydrochloride/sodium polyphenylene sulfonate coacervates, coated with eudragit S100 to improve the stability and colon targeting ability, named EU-Coac, is developed. Emodin, an active ingredient in traditional Chinese herbs proven to alleviate UC symptoms, is loaded in EU-Coac (EMO@EU-Coac) showing good stability in gastric acid and pepsin and pH-responsive release behavior. After oral administration, EMO@EU-Coac can effectively target and retain in the colon, displaying good therapeutic effects on UC treatment through attenuating inflammation and oxidative stress response, repairing colonic epithelia, as well as regulating intestinal flora balance. In short, this study provides a novel and facile coacervate microdroplet delivery system for UC treatment. 相似文献
7.
具有纳滤特性的pH响应性膜在小分子分离体系中具有广泛应用前景。文中以铸膜液浓度为25%的乙烯-乙烯醇共聚物(EVAL)超滤膜为基膜,接枝具有pH响应性的功能单体甲基丙烯酸二甲氨基乙酯,制备pH响应性EVAL膜,通过考察膜对标准物聚乙二醇(PEG)与无机盐的截留性能,研究其纳滤特性。结果表明,当pH小于pKa时,pH响应性EVAL膜对聚乙二醇(PEG)与无机盐的截留效果均明显高于未接枝膜,接枝率6%的接枝膜对PEG 800、PEG 1000及PEG 2000的截留率均达到90%以上,对二价阳离子的截留率达到80%以上,无机盐的截留顺序为:CaCl_2MgCl_2MgSO_4NaClNa2SO_4。当pH大于pKa时,PEG及无机盐截留率明显下降,膜对PEG 1000的截留率由95.6%降至62.9%,对MgCl_2截留率降至30.6%,截留率及膜水通量变化存在显著的pH响应性。 相似文献
8.
目的 综述近年来天然高分子基pH响应智能包装材料的研究进展,分析提高色素稳定性、灵敏性和准确性的方法,为pH响应的智能指示包装进一步发展提供科学的理论基础。方法 介绍pH响应智能包装的实现途径及变色机理,通过对已有研究的现状和结果进行分析,重点总结提高pH指示剂稳定性、灵敏性、准确性的方法,讨论天然多糖、蛋白质及脂质作为基质在pH响应智能包装材料中的最新应用进展,对pH响应天然高分子基智能包装材料目前存在的问题及未来的发展趋势进行分析。结论 包括多糖、蛋白质、脂质及其组合在内的天然高分子材料已经在食品保鲜及指示薄膜和涂层方面得到了广泛应用。目前研究的总体目标是提高pH响应包装材料的安全性和质量,降低成本和对环境的负面影响,实现智能包装的工业化生产。 相似文献
9.
研究了两步光接枝法制备pH敏感响应分离膜的过程中接枝率随实验条件的变化及其对响应性的影响。实验以聚丙烯为基膜、丙烯酸(AA)为接枝单体,用水作溶剂,考察了光引发剂二苯甲酮(BP)的浓度、丙烯酸的浓度以及反应时间对接枝率的影响,采用傅氏变换红外光谱和扫描电镜分别对高分子膜的化学成分和膜的形貌进行了表征。研究结果表明,控制接枝率在1%~6%时,接枝膜具有较为显著的pH值响应性;接枝率为3%时,接枝膜的pH值响应系数达2.3,当接枝率大于6%和接枝率小于1%时,膜几乎不具pH值敏感响应性。为获得满意的pH值敏感响应性,必须将其接枝率控制在适当的范围内。 相似文献
10.
以硝酸铈铵为引发剂,将具有pH响应的聚丙烯酸(PAA)接枝到电纺纤维素(Cell)纳米纤维膜上,制备了pH响应纤维素接枝聚丙烯酸(Cell-g-PAA)纳米纤维水凝胶。研究了接枝单体丙烯酸(N)与纤维素(c)质量比对Cell-g-PAA形貌、接枝率和溶胀性的影响。结果表明:m(N)∶m(c)值从5增加到10,接枝率从11%急剧增加到28%,然后趋于平稳;而m(N)∶m(c)值从5增加到15,溶胀率从(15.2±1.6)g/g增加到(46.1±4.9)g/g,然后下降。同时,研究了pH值和离子强度对水凝胶溶胀率的影响,pH值从2.2增加到7.8时,水凝胶的溶胀率从(31.3±2.5)g/g增加到(42.7±3.2)g/g,pH值进一步增大,溶胀率降低;溶液中离子强度从0mol/L增加到0.15mol/L,水凝胶溶胀率从(36.2±2.6)g/g降低到(21.4±1.4)g/g。本研究为制备快速响应pH水凝胶提供了一种新方法。 相似文献
11.
以壳聚糖为膜基材,制备壳聚糖基多孔膜,并在超临界二氧化碳中,以丙烯酸(AA)和4-乙烯基吡啶(4-VP)为接枝共聚单体,对壳聚糖多孔膜进行接枝,制备了p H-响应型壳聚糖多孔膜。采用傅里叶变换红外光谱和X射线衍射等对接枝膜的结构进行表征,考察了2种接枝单体的摩尔比及反应压力对壳聚糖膜接枝率的影响,以及接枝膜对蛋白质的吸附。红外结果表明聚丙烯酸与聚4-乙烯基吡啶均接枝到壳聚糖膜上。当AA/4-VP单体摩尔比由3∶1增加至6∶1时,接枝率由7.12%逐渐增大至13.36%,此后呈下降趋势。且随着反应压力的提高,壳聚糖膜接枝率先增长后降低,当反应压力在19 MPa时,得到较高的接枝率(13.36%)。当溶液p H=2~10时,壳聚糖接枝膜的水通量随着p H值的增大而降低。蛋白质吸附实验显示,在p H为4.8时接枝膜获得最大比表面积吸附量5.76 mg/cm2。 相似文献
12.
超疏水耐水洗的pH响应性聚苯胺变色织物 总被引:1,自引:0,他引:1
采用一种表面存在大量微/纳米裂纹、 横截面为十字型异型纤维的涤棉混纺织物作为基底, 以全氟壬烯氧基苯磺酸钠(OBS)作为掺杂剂, FeCl3为氧化剂, 通过原位化学氧化法制备得到了具有超疏水性能和耐水洗的聚苯胺/涤棉复合导电织物(PANI/CPCCT), 研究了pH对PANI/CPCCT的影响。结果表明, 该导电织物的水接触角最高可达162°, 在碱性条件下仍具有良好的导电性能和疏水性, 并且其颜色也随着pH从1增大至14而发生由墨绿色-蓝绿色-蓝黑色-褐色之间的可逆变化, 其浸润性可快速响应外界酸度的变化, 发生超疏水到超亲水的可逆转变, 具有良好的pH响应性。此外, PANI/CPCCT可耐受弱酸性溶液的洗涤, 并可通过在强酸溶液中浸泡而重复使用, 具有较强的应用性。这些优良的性能, 使其有望在开发酸度控制的浸润性开关、 自清洁织物、 酸度检测等方面获得应用。 相似文献
13.
A non-destructive, safe and practical strategy to produce high quality graphene in high yield is urgently required, since this would pave the way for a wide range of applications of graphene in the future. Here we present a pH-responsive water-dispersible method for the exfoliation and functionalization of graphene by using lysozyme. The pH-responsive dispersion of graphene may be useful for the reversible assembly of multicomponent/multifunctional nanohybrid materials and nanoscale electronic devices. More importantly, composites can be easily constructed through the interactions between disulphide groups in lysozyme and gold nanoparticles (AuNPs). The resulting graphene-AuNPs composites show excellent catalytic activity towards reduction of o-nitroaniline by NaBH4. Since lysozyme is low cost and has antibacterial properties, and has been widely used in food preservation, medicine and the pharmaceutical industry, our approach may open a new scalable route for the manufacture of high-quality, nondestructive graphene for practical applications. 相似文献
14.
以欧车前胶(PSY)、丙烯酸(AA)和黑云母(BT)为原料,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,过硫酸铵(APS)为引发剂,采用水溶液聚合法制备了欧车前胶接枝聚丙烯酸复合黑云母(PSY-g-PAA/BT)高吸水性树脂。考察了不同含量BT树脂在蒸馏水和盐水中的吸水倍率和溶胀行为。红外光谱和溶胀性能测试结果表明,... 相似文献
15.
The purpose of this study was to prepare modified-release dosage of indomethacin (IND) in the form of micromatrices based on a superabsorbent hydrogel (SAH), poly(acrylic acid), partly sodium salt-g-poly(ethylene oxide) (PAAc-Na-g-PEO). A soaking procedure was used for the preparation of drug-loaded hydrogel micromatrices. The amount of IND, volume of drug-loading solution, and amount of PAAc-Na-g-PEO granules used for preparing micromatrices were the independent factors. The dependent factors were the measured responses from micromatrices, that is, percent recovery, percent entrapment efficiency, and the time at which 63.2% of the drug was released (Td, minutes). A three-factor, three-level full factorial design (33) was created to optimize formulations. Nonlinear regression analysis indicated a good correlation between the measured responses and the independent factors. Optimum responses were obtained from medium levels of IND and SAH and low level of drug-loading solution. Differential scanning calorimetry, X-ray diffraction analysis, and scanning electron micrography indicated that IND crystals are physically adsorbed into the pores and irregular spaces of the hydrogel. 相似文献
16.
为设计一种能够响应pH的、新型多功能创面敷料,使用季铵化壳聚糖(QCS)、接枝了磺胺嘧啶(SD)的氧化葡聚糖(Dex-CHO/SD)和妥布霉素(TOB),通过席夫碱键和氢键反应形成DSTQ水凝胶。对水凝胶的形貌、降解性、抑菌性、细胞相容性、血液相容性等性能进行研究。结果表明:具有三维孔状结构的DSTQ水凝胶可以响应感染造成的pH降低,进而发生降解,释放药物;DSTQ水凝胶对铜绿假单胞菌的抑制率显著高于金黄色葡萄球菌;DSTQ水凝胶毒性低,生物安全性高,与L929细胞共培养3 d后,细胞活力高于95%;DSTQ水凝胶具有良好的血液相容性,溶血率远小于5%;细胞在DSTQ水凝胶表面能够快速迁移,有利于伤口愈合;当DSTQ水凝胶负载生长因子后具有良好的抗炎效果。研究结果表明,DSTQ水凝胶可以作为新型创面敷料,有望应用于临床促伤口愈合。 相似文献
17.
目的 对pH响应型智能包装在食品包装领域的发展现状进行综述和分析,促进食品包装的功能化、智能化和绿色生态一体化。方法 简要介绍智能包装的分类及作用,分析pH响应型智能包装的原理,并总结pH响应型智能包装指示剂的类型及其特点。围绕pH响应型智能包装在水产品、乳制品和果蔬等方面的实际应用,对其制备方法、性能等方面进行综述。讨论pH响应型智能包装在食品包装领域的研究潜力和挑战。结论 pH响应型智能包装可以准确评估食品的品质和新鲜度,在食品包装领域具有广阔的应用前景。 相似文献
18.
Amphiphilic chitosan-graft-poly(2-(N,N-diethylamino)ethyl methacrylate)-block-poly(ethylene oxide) (CS-g-(PDEAEMA-b-PEO)) copolymer was synthesized by the combination of atom transfer radical polymerization (ATRP) and click chemistry. The copolymer was characterized by 1H NMR spectrum. The self-assembly and pH-responsive properties of CS copolymer were investigated by TEM, DLS, and transmittance in water. The micelle sizes can be adjusted through the alteration of the pH values of solutions. The presence of PEO segments can improve the hydrophilicity of the copolymer and avoid the excessive aggregation of the micelles. CS-g-(PDEAEMA-b-PEO) copolymer has both the unique properties of PDEAEMA-b-PEO and chitosan, and will have the potential applications in biomedical field. 相似文献
19.
《材料科学技术学报》2024,200(33)
Polyetheretherketone(PEEK)has been recognized for its immense potential in hard tissue repair appli-cations due to its mechanical properties resembling those of natural bones.However,the inherent bioin-ertness of pristine PEEK results in insufficient osseointegration.Moreover,implant-associated infection(IAI)has become a serious threat in orthopedic surgery.These risks usually lead to implant loosening,delayed healing,and even the failure of implantation,hampering many clinical applications of PEEK.In this study,we present a facile strategy to endow PEEK implants with enhanced osseointegration and pH-responsive antibacterial activity.Briefly,pristine PEEK was first treated with mixed acids to obtain a porous structure(referred to as SNPEEK),and then the metal-phenolic networks(MPN)coating was prepared using layer-by-layer(LbL)assembly consisting of Sr2+and tannin acid(TA)(referred to as ST coating).The results demonstrated that the dual-functional PEEK displayed enhanced antibacterial activ-ity in pH-responsive manner.At pH 7.4,the antibacterial ratios were 71.72%and 66.79%against Staphylo-coccus aureus(MSSA,ATCC 25,923)and methicillin-resistant Staphylococcus aureus(MRSA,ATCC BAA-40),respectively.Remarkably,at pH 5.5,the antibacterial activities significantly increased,resulting in killing ratios of 99.98%and 100%,respectively.Furthermore,the dual-functional PEEK promoted osteogenic dif-ferentiation of pre-osteoblasts(MC3T3-E1)and migration of human umbilical vascular endothelial cells(HUVECs).In addition,the dual-functional PEEK demonstrated effective anti-infection ability and desir-able new bone formation ability in vivo compared to both pristine PEEK and SNPEEK implants.Overall,this study provides a promising strategy to endow PEEK implants with effective osseointegration and anti-infective ability,representing a prospective solution to address current clinical challenges associated with PEEK implants. 相似文献
20.
《Advanced Powder Technology》2022,33(11):103830
The present work exhibits an alternative route to design a nano-carrier using simple electrostatic interactions of biopolymeric layers on Mesoporous Silica Nanoparticle surface using Layer by Layer (LbL) technique. The doxorubicin (DOX) loaded MSN nano-carrier is coated with positively charged chitosan followed by a coating of negatively charged sodium carboxymethyl cellulose (Na-CMC) to form a DOX-loaded MSN Core-Shell Matrix (DOX-MSN CSM). The prepared MSN nano-carrier exhibits a high encapsulation efficiency of DOX (~93 %) due to its porous nature (~832 m2/gm) and negative surface charge (-21.5 mV). It exhibits a controlled release of DOX (~21 %) at physiological pH (7.4 pH) and improved drug release (~67 %) at cancer cells pH (5.4 pH) after 48 h. Further, the in-vitro cell line study using MDA-MB 231 cells reconfirms the slower and controlled release of DOX from the engineered DOX-MSN CSM. The confocal microscopy result shows that the DOX is internalized via endocytosis into the nucleus of the cells. The cell viability assay confirms more cells viable (~76 %) for DOX-MSN CSM than free DOX (~49 %) at the end of 24 h. The present study shows an alternate route to the conventional complex multi-step processes such as coupling reactions or chemical crosslinkers involving solvents. The proposed MSN core–shell matrix can be a potential nano-carrier for cancer drug delivery. 相似文献