The In Vivo Fate and Strategies of Improving the Targeting Effect of Nanoparticles

2021 ◽  
Vol 22 (8) ◽  
pp. 844-844
Author(s):  
Jihui Tang ◽  
Jianping Zhou
Keyword(s):  
2020 ◽  
Vol 21 (5) ◽  
pp. 1856
Author(s):  
Qi Shuai ◽  
Yue Cai ◽  
Guangkuo Zhao ◽  
Xuanrong Sun

On account of their excellent capacity to significantly improve the bioavailability and solubility of chemotherapy drugs, amphiphilic block copolymer-based micelles have been widely utilized for chemotherapy drug delivery. In order to further improve the antitumor ability and to also reduce undesired side effects of drugs, cell-penetrating peptides have been used to functionalize the surface of polymer micelles endowed with the ability to target tumor tissues. Herein, we first synthesized functional polyethylene glycol-polylactic acid (PEG-PLA) tethered with maleimide at the PEG section of the block polymer, which was further conjugated with a specific peptide, the transactivating transcriptional activator (TAT), with an approved capacity of aiding translocation across the plasma membrane. Then, TAT-conjugated, paclitaxel-loaded nanoparticles were self-assembled into stable nanoparticles with a favorable size of 20 nm, and displayed a significantly increased cytotoxicity, due to their enhanced accumulation via peptide-mediated cellular association in human breast cancer cells (MCF-7) in vitro. But when further used in vivo, TAT-NP-PTX showed an acceleration of the drug’s plasma clearance rate compared with NP-PTX, and therefore weakened its antitumor activities in the mice model, because of its positive charge, its elimination by the endoplasmic reticulum system more quickly, and its targeting effect on normal cells leading towards being more toxic. So further modification of TAT-NP-PTX to shield TAT peptide’s positive charges may be a hot topic to overcome the present dilemma.


Author(s):  
Mack Biyiklioglu

Photodynamic therapy and photothermal therapy as non-invasive treatment methods have been receiving more and more attention. The report shows that zinc(II) phthalocyanine (Pc2) modified by perphenazine forms nanoparticles with a particle size of 110 nm by [Formula: see text]–[Formula: see text] stacking in water. It has good photothermal effect when illuminated by 680 nm laser in aqueous solution. In addition, its ability to produce active oxygen is 2.3-fold that of methylene blue, so Pc2 also has a good photodynamic effect. In vivo fluorescence shows that Pc2 has a good targeting effect on tumors. Under the synergistic effect of photodynamic therapy and photothermal therapy, Pc2 has good tumor inhibition efficiency.


2015 ◽  
Vol 23 (6) ◽  
pp. 683-688 ◽  
Author(s):  
Ha Phuong Thu ◽  
Nguyen Hoai Nam ◽  
Bui Thuc Quang ◽  
Ho Anh Son ◽  
Nguyen Linh Toan ◽  
...  
Keyword(s):  

RSC Advances ◽  
2015 ◽  
Vol 5 (52) ◽  
pp. 41393-41400 ◽  
Author(s):  
Zhenqing Hou ◽  
Jinyan Lin ◽  
Yanxiu Li ◽  
Fuqiang Guo ◽  
Fei Yu ◽  
...  

Surface functionalization of a PEGylated chitosan nanoparticle with dual-acting methotrexate drives a tumor-targeting effect and also introduces an anticancer effect.


Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.


Author(s):  
E. J. Kollar

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.


Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.


Author(s):  
H. Engelhardt ◽  
R. Guckenberger ◽  
W. Baumeister

Bacterial photosynthetic membranes contain, apart from lipids and electron transport components, reaction centre (RC) and light harvesting (LH) polypeptides as the main components. The RC-LH complexes in Rhodopseudomonas viridis membranes are known since quite seme time to form a hexagonal lattice structure in vivo; hence this membrane attracted the particular attention of electron microscopists. Contrary to previous claims in the literature we found, however, that 2-D periodically organized photosynthetic membranes are not a unique feature of Rhodopseudomonas viridis. At least five bacterial species, all bacteriophyll b - containing, possess membranes with the RC-LH complexes regularly arrayed. All these membranes appear to have a similar lattice structure and fine-morphology. The lattice spacings of the Ectothiorhodospira haloohloris, Ectothiorhodospira abdelmalekii and Rhodopseudomonas viridis membranes are close to 13 nm, those of Thiocapsa pfennigii and Rhodopseudomonas sulfoviridis are slightly smaller (∼12.5 nm).


Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.


Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.


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