Toxicology Perspective of Nanopharmaceuticals: A Critical Review

Author(s):  
S C Patel ◽  
Patel R.C ◽  
Saiyed M.A.

For the last 10 years pharmaceutical research and industry has elucidated several innovations and practices in pharmaceutical nanotechnology. Due to the increasing use of nanoparticles, the risk of human exposure rapidly increases and reliable toxicity test systems are urgently needed. Nanotoxicology refers to the study of the interactions of nanostructures with biological systems with an emphasis on the relationship between the physical and chemical properties of nanostructures with induction of toxic biological responses. It involves their unique biodistribution, clearance, accumulation, immune response and metabolism. An understanding of the relationship between the physical and chemical properties of the nanostructure and their in-vivo behavior would provide a basis for assessing toxic response and more importantly could lead to better predictive models for assessing toxicity. The current regulations for nanoparticles containing products are still in a nascent stage. The advantages of nanoparticles led to failures in noticing the toxic outcomes in living organisms. Major changes are required by considering several factors including environmental, health and safety issues. The rapid commercialization of nanotechnology requires thoughtful open discussion of broader societal impacts and urgent toxicological oversight action.

1977 ◽  
Vol 1977 (1) ◽  
pp. 617-620 ◽  
Author(s):  
Shinichi Nagata ◽  
Goro Kondo

ABSTRACT Changes with elapsed time are presented for five kinds of oils that were studied through the analyses of GLC method, where particularly we made an attempt to examine the relationship among specific gravity, viscosity, and the amount of water in oils. Furthermore, we tried to evaluate a few processes of various kinds of changes on the physical and chemical properties of oils such as evaporation, biodegradation, and photo-decomposition. The evaporation process was found to affect mainly paraffins with smaller boiling points, below the number of C12-C13, for 21 days, while due to the action of marine bacteria, normal paraffins were effectively degraded (ca. 50%) after 15 days except for branched ones. Moreover, it was also found that the aromatic hydrocarbons with anthracene ring and heteroaromatic ones, which were not easily decomposed by the processes mentioned above, were fairly decomposed by photo-irradiation for 10 hours.


2012 ◽  
Vol 567 ◽  
pp. 62-65 ◽  
Author(s):  
Xin Hua Zhu ◽  
Li Guang Zhu ◽  
Yu Liu ◽  
Peng Fei Wang

Basicity is an important parameter which can determine the performance of continuous casting fluxes, and it have different effects on flux of various physical and chemical properties. This paper discusses the relationship and impact between basicity and the physical and chemical properties of flux, Which proved how changes of basicity affect physical and chemical properties of flux, and then how it affects the flux function .


Author(s):  
Andrey A. Mezin ◽  
◽  
Mariya Y. Shumskayte ◽  
Olga V. Rodionova ◽  
Aleksandra I. Buruhina ◽  
...  

The paper presents the results of experimental studies on the dielectric and NMR characteristics of oil samples. The relationship between the complex dielectric constant and the NMR parameters of oil with its density, viscosity and group composition has been established. It was found that the results of these methods directly depend on the content of resinous–asphaltenic compounds in the composition of the studied oil sample.


2020 ◽  
pp. 088532822095089
Author(s):  
Yuanxing Zhou ◽  
Xiaochi Ma ◽  
Zhonghai Li ◽  
Bo Wang

An effective and viable hemostatic agent is important for stopping bleeding during surgery. However, it is difficult to achieve hemostasis at uneven or deep bleeding sites using a gelatin sponge. A flowable hemostatic agent has therefore been developed by processing and improving gelatin sponge, to address bleeding under these conditions. In this study, we evaluated the efficacy, safety, and physical and chemical properties of this flowable hemostatic agent in various experiments. We examined its efficacy for stopping bleeding in a rabbit model of liver abrasion in vivo, and compared its efficacy in dynamic coagulation and erythrocyte aggregation tests with gelatin sponge in vitro. We also investigated its safety in rat histocompatibility and acute systemic toxicity tests in mice in vivo, and in hemolysis tests in vitro, to determine if the flowable hemostatic agent induced any pathological reactions or adverse events. In terms of its physical and chemical properties, we analyzed the morphology and chemical bonds of the flowable hemostatic agent by optical and electron microscopy and infrared spectroscopy, and its absorbency and density. The flowable hemostatic agent resulted in a shorter mean bleeding time, less bleeding, greater likelihood of successful hemostasis, and reduced clotting time compared with gelatin sponge. The flowable agent produced some changes in physical morphology, but no pathological changes or undesirable outcomes were detected. This flowable topical hemostatic agent thus provides a safe and more effective hemostatic method than gelatin sponge, and more promising results for intraoperative hemostasis, especially on uneven or deep bleeding surfaces.


2021 ◽  
Vol 2 ◽  
Author(s):  
Hua Lin ◽  
Cuilan Yin ◽  
Anchun Mo

Zirconia, with its excellent mechanical properties, chemical stability, biocompatibility, and negligible thermal conductivity, is ideal for dental and orthopedic applications. In addition, the biocompatibility of zirconia has been studied in vivo, and no adverse reactions were observed when zirconia samples were inserted into bone. However, their use is controversial among dentists and researchers, especially when compared with mature implants made of titanium alloy. The advantages and limitations of zirconia as biomaterials, such as implant materials, need to be carefully studied, and the design, manufacture, and clinical operation guidelines are urgently required. In this review, the special components, microstructure, mechanical strength, biocompatibility, and the application of zirconia ceramics in biomaterials are detailly introduced. The review highlights discussions on how to implement innovative strategies to design the physical and chemical properties of zirconia so that the treated zirconia can provide better osteointegration after implantation.


2012 ◽  
Vol 32 (2-4) ◽  
pp. 101-110 ◽  
Author(s):  
Jian-Ming Ouyang ◽  
Zhi-Yue Xia ◽  
Guang-Na Zhang ◽  
He-Qun Chen

AbstractKidney stones are mainly composed of inorganic crystals such as calcium oxalate (CaOxa). At present, kidney stones can be detected only after their formation, which causes great suffering for patients. If kidney stones can be detected prior to their formation, they can be effectively prevented, which presents great commercial value. In this paper, we review the differences in urine nanocrystallites between stone-forming patients and healthy controls, as well as the relationship between nanocrystallites in urine and the formation of kidney stones. These differences are microcrystalline morphology, aggregation, size and distribution, chemical composition, Zeta potential and stability. The results showed that the formation of kidney stones is closely related to the nature of nanocrystallites. Through the regulation of the physical and chemical properties of nanocrystallites, the formation and recurrence of kidney stones are possibly inhibited.


1995 ◽  
Vol 41 (13) ◽  
pp. 50-54 ◽  
Author(s):  
Rosetta N. Reusch

It is increasingly clear that poly(3-hydroxybutyrate) (PHB) is not just an inert storage polymer, confined to certain bacteria, but a ubiquitous, interactive, solvating biopolymer involved in important physiological functions. Low molecular weight PHB, complexed to other macromolecules (c-PHB), is widely distributed in biological cells, being found in representative organisms of nearly all phyla. Complexation modifies the physical and chemical properties of c-PHB, allowing it to pervade aqueous as well as hydrophobic regions of the cell, and as a result c-PHB can be found in cytoplasm and intracellular fluids as well as in membranes and lipoproteins. The lipidic homopolymer associates with other macromolecules primarily via its ester carbonyl oxygens, which can act as hydrogen-bond acceptors or as ligands for coordinate bonds to cations. The spacing of the electron-donating groups along the flexible backbone allows for multiple bonding interactions, and forms the basis for the ability of c-PHB to bind to proteins, or to form ion-conducting complexes with salts. The singular ability of c-PHB to dissolve salts and facilitate their transfer across hydrophobic barriers defines a potential physiological niche for c-PHB in cell metabolism.Key words: polyhydroxybutyrate, polyphosphate, polymer electrolyte, ion transport.


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