Theranostic Applications of Au-Ag Nanocages and Nanocomposites

We report two novel biomedical applications of Au/Ag alloy nanoparticles called nanocages. In the first case, composite nanoparticles consisting of a nanocage core and a mesoporous silica shell doped with a photodynamic sensitizer Yb-2,4-hematoporphyrin were fabricated, characterized, and tested in vitro and ex vivo. In the second part of the study, Ag nanocubes and Au/Ag nanocages were applied to a multiplexed dot immunoassay. The assay principle is based on the staining of analyte drops on a nitrocellulose membrane strip by using multicolor nanoparticles conjugated with biospecific probing molecules. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3493

Synthesis and Study of PNIPAM Nanogels Incorporated with Colloidal Silver

Composite nanoparticles consisting of polymer gels with incorporated silver nanoparticles have been synthesized. The synthesis comprises two main stages. Initially, monodisperse hydrogel particles with a controlled diameter of approximately 500 nm are obtained by N-isopropylacrylamide polymerization. Then, silver ions are reduced on the surface of the polymer network. Variations in the concentration ratio between reductants and silver nitrate make it possible to produce silver nanoparticles with sizes in a range of 10-30 nm and different packing densities on the gel particle surface. The resultant nanocomposites have been studied by transmission electron microscopy, spectrophotometry, and dynamic light scattering. Depending on the size and packing density of the silver nanoparticles on the polymer particle surface, the plasmon resonance of the nanocomposites varies in a range of 420-750 nm, which determines variations in the color of the colloid from yellow, orange, and red to blue and blue-green. After the inclusion of silver nanoparticles, nanogels of poly(N-isopropylacrylamide) retain their capability for thermosensitive phase transition with a lower critical mixing temperature of 31 °C. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3509

Morphokinetics of mesenterial lymphatic node cell populations in exposure of gold nanoparticles within experimental work

The research goal is to investigate the influence of gold nanoparticles with different size (1-3 nm, 15 nm and 50 nm) on the morphokinetics of mesenterial lymphatic node cell populations of healthy laboratory animals. Experiment included 24 white rats. The investigation was conducted in 4 groups of animals. The animals were administered the gold nanoparticles orally for 15 days. It was established that the oral administration of gold nanoparticles caused the changes of morphokinetics of mesenterial lymphatic node cell populations. The morphological alterations in the mesenterial lymphatic nodes assisted in activation of migration processes, the proliferation and differentiation. The immu-nomodulatory action of gold nanoparticles was prove

Mesoporous Silica and Composite Nanostructures for Theranostics

We discus methods for fabrication of silica and composite nanoparticles, which can be used in various biomedical applications. The most promising types of such nanostructures are hollow silica nanosheres, sil-ica coated plasmon-resonant nanoparticles (gold nanorods and gold-silver nanocages) and nanorattles. Mesoporous silica shell can be doped by desirable targeting molecules. Here we present the results of for-mation of nanocomposites composed of gold nanorods and double-layer silica shell. The secondary mesopo-rous silica shell is doped with a photosensitizer (hematoporphyrine in our case). We demonstate some of promising theranostics applications of these nanocomposites for bioimaging and in vivo therapy of tumors. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3548

Mesoporous Silica and Composite Nanostructures for Theranostics

We discus methods for fabrication of silica and composite nanoparticles, which can be used in various biomedical applications. The most promising types of such nanostructures are hollow silica nanosheres, sil-ica coated plasmon-resonant nanoparticles (gold nanorods and gold-silver nanocages) and nanorattles. Mesoporous silica shell can be doped by desirable targeting molecules. Here we present the results of for-mation of nanocomposites composed of gold nanorods and double-layer silica shell. The secondary mesopo-rous silica shell is doped with a photosensitizer (hematoporphyrine in our case). We demonstate some of promising theranostics applications of these nanocomposites for bioimaging and in vivo therapy of tumors. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3548

The assessment of molecular markers of cell interaction and lipid peroxidation in rats with alloxan diabetes and trans- planted liver cancer after intravenous injection of gold nanorods

Цель: оценить воздействие однократного внутривенного введения покрытых полиэтиленгликолем золотых наностержней на молекулярные маркеры межклеточного взаимодействия и показатели перекисного окисления в сыворотке крови четырех групп крыс: интактных, с аллоксановым диабетом, с перевитым раком печени; с перевитым раком печени на фоне аллоксанового диабета. Материалы и методы. Активность перекисного окисления липидов оценивалась по показателям гидроперекисей липидов, малонового диальдегида и молекул средней массы с использованием общепринятых спектрофотометрических методов, исследования молекулярных маркеров — фактора некроза опухоли TNF-a, инсулиноподобного фактора роста IGF-1, васкулоэн-дотелиального фактора роста VEGF-C проводились в сыворотке крови методом иммуноферментного анализа. Результаты. Выявлено, что при однократном внутривенном введении золотых наностержней не происходит значительного изменения количества маркеров межклеточного взаимодействия и показателей перекисного окисления липидов. в периферической крови. Заключение. Полученные результаты позволяют рекомендовать использование покрытых полиэтиленгликолем золотых наностержней в экспериментальной онкологии.</p

Analysis of accumulation and biodistribution of gold nanoparticles in mesenteric lymph nodes by oral administration

The aim of the article is to conduct analysis of accumulation and biodistribution of gold nanoparticles in the structural and functional areas of mesenteric lymph nodes of white rats. Particular attention is paid to the size and duration of oral administration. Material and Methods: Dark field microscopy with Leica DM 2500 microscope has been used to assess biodistribution of gold nanoparticle. The histochemical reaction of silver amplification with silver lactate by Danscher has been used to confirm gold nanoparticles identification. Results: It has been found that regardless of the duration of administration gold nanoparticles of 1-3 nm have not been detected by these methods in the lymph nodes. Gold nanoparticles of 15 and 50 nm have been found out in the form of clusters in the cytoplasm of macrophages and lymphocytes mainly in the mantle zone of lymphoid follicles and brain strands. Conclusion: It has been established that the gold nanoparticles of 15 and 50 nm has been detected in the form of clusters in the cytoplasm of macrophages and lymphocytes

Morphological changes in the organs of laboratory animals during the prolonged oral administration of gold nanoparticles

The purpose of the article is to assess the severity of the morphological changes in the internal organs of laboratory animals with prolonged oral administration of gold nanoparticles of different sizes. Material and methods: The experiment was carried out on 40 albino rats which were divided into 4 groups. Animals of the experimental group received oral gold nanoparticles by the appropriate scheme. Results: At comparing the morphological changes in the internal organs of laboratory animals it was established that the introduction of gold nanoparticles of different sizes leads to the same type of disturbances of morphological structure, the gold nanoparticles of 1-3 and 50 nm cause the most expressive changes. Conclusion: The most significant morphological modifications in the internal organs were caused by gold nanoparticles of 1-3 and 50 nm. It points out to the size-dependence of the effect of gold nanoparticles

Morphokinetics of mesenterial lymphatic node cell populations at exposure of gold nanoparticles in experiment

The influence of gold nanoparticles with different size (1-3 nm, 15 nm and 50 nm) on the morphokinetics of mesenterial lymphatic node cell populations of healthy laboratory animals was investigated. It was established that the oral administration of gold nanoparticles caused the changes of morphokinetics of mesenterial lymphatic node cell populations. The morphological reorganizations in the mesenterial lymphatic nodes testified about activation of migration processes, the proliferation and differentiation processes of immunocompetent cells, which assumes the presence of immunomodulating action of gold nanoparticles

Surface modification of orthodontic implants by nanocomposite coatings based on chitosan and metals

Purpose: to study the properties of nanostructured coatings in orthodontic implants. Material and methods. Low and average molecular mass chitosan, 3-amynopropil-3-methoxysylan and suspensions of 5 nm and 10 nm gold nano-spheres stabilized with natrium citrate were used for nanocomposed surfaces. 2mg/ml polyethylenamin water solution was used for making the underlayer before putting polyion coverage using «POLYION-1M». The polyion covering dynamics was studied by polyquartz weighing method. Morphology of created layers was studied with atomic microscopy, elements were studied by secondary ion mass-spectrometry. Results. The best transmission among structures of chito-san/metals was showed by low molecular mass of chitosan and 8-1 Onm nanoparticles of metals. Analysis of roughness of surface shows that nanoparticles of gold make the most solid surface on 3-amynopropil-3-methoxysylan underlayer. Conclusion. The development of biocomparative materials in maxillofacial surgery is considered to be effective method of decreasing the risk of post-operative inflammatory complications by local antibacterial effect