Actinide-contaminated Skin: Comparing Decontamination Efficacy of Water, Cleansing Gels, and DTPA Gels

Actinide Decorporation: A Review on Chelation Chemistry and Nanocarriers for Pulmonary Administration

Chelation is considered the best method for detoxification by promoting excretion of actinides (Am, Np, Pu, Th, U) from the human body after internal contamination. Chemical agents that possess carboxylic acid or hydroxypyridinonate groups play a vital role in actinide decorporation. In this review article, we provide considerable background details on the chelation chemistry of actinides with an aim to formulate better decorporation agents. Nanocarriers for pulmonary delivery represent an exciting prospect in the development of novel therapies for actinide decorporation that both reduce toxic side effects of the agent and improve its retention in the body. Recent studies have demonstrated the benefits of using a nebulizer or an inhaler to administer chelating agents for the decorporation of actinides. Effective chelation therapy with large groups of internally contaminated people can be a challenge unless both the agent and the nanocarrier are readily available from strategic national stockpiles for radiological or nuclear emergencies. Sunflower lecithin is particularly adept at alleviating the burden of administration when used to form liposomes as a nanocarrier for pulmonary delivery of diethylenetriamine-pentaacetic acid (DTPA) or hydroxypyridinone (HOPO). Better physiologically-based pharmacokinetic models must be developed for each agent in order to minimize the frequency of multiple doses that can overload the emergency response operations.

A Simple, Rapid, Comparative Evaluation of Multiple Products for Decontamination of Actinide-contaminated Rat Skin Ex Vivo

ABSTRACT

Decontamination of skin is an important medical countermeasure in order to limit potential internal contamination by radionuclides such as actinides. Minimizing skin surface contamination will ultimately prevent internal contamination and subsequent committed effective dose as well as contamination spreading. The decontamination agents tested on a rat skin ex vivo model ranged from water to hydrogel wound dressings. A surfactant-containing cleansing gel and calixarene nanoemulsion with chelation properties demonstrated marked decontamination efficacies as compared with water or the chelator DTPA. Based on efficacy to remove different actinide physicochemical forms from skin, the results demonstrate that all products can remove the more soluble forms, but a further component of emulsifying or tensioactive action is required for less soluble forms. This indicates that for practical purposes, successful decontamination will depend on identification of the actinide element, the physicochemical form, and possibly the solvent. This study offers a simple, quick, cheap, reproducible screening method for efficacy evaluation of multiple products for removal of a variety of contaminants.

Efficacy of soap and water-based skin decontamination using in vitro animal models: A systematic review

Water and/or soap and water solutions have historically been used as first-line decontamination strategies for a wide variety of dermal contaminants from workplace exposure, environmental pesticides, and civilian chemical warfare. Although water and/or soap and water solutions are often considered a gold standard of decontamination, many studies have found other decontamination methods to be superior. This systematic review summarizes the available data on in vitro animal models contaminated with a various chemicals and their decontamination with water and/or soap and water solutions using in vitro animal models. A comprehensive literature search was performed using Concordance, Embase, PubMed, Medline, Web of Science, and Google Scholar to find in vitro animal studies that provided data on dermal decontamination using water and/or soap and water solutions. Five studies were included that analyzed 11 contaminants across two in vitro animal models (rats and pigs). Water alone was used as a decontamination method for 63.6% of the contaminants (n = 7/11) and water and soap solutions for decontamination in 54.6% of contaminants (n = 6/11). Water alone provided incomplete contaminant removal of five of seven contaminants studied; soap and water did not show significant difference in decontamination when compared with other solutions for all four contaminants and was superior to water for both contaminants studied. Water and/or soap and water are used as decontamination strategies for a variety of dermal contamination events, but for many contaminants, they do not provide complete contamination when compared with newer decontamination solutions studied with in vitro animal models.

Skin decontamination procedures against potential hazards substances exposure

Decontamination of unprotected skin areas is crucial to prevent excessive penetration of chemical contaminants after criminal or accidental release. A review of literature studies was performed to identify the available decontamination methods adopted to treat skin contamination after chemical, radiological and metal exposures. In this bibliographic review, an overview of the old and recent works on decontamination procedures followed in case of potential hazards substances contaminations with a comparison between these systems are provided. Almost all data from our 95 selected studies conducted in vitro and in vivo revealed that a rapid skin decontamination process is the most efficient way to reduce the risk of intoxication. The commonly-used or recommended conventional procedures are simple rinsing with water only or soapy water. However, this approach has some limitations because an easy removal by flushing may not be sufficient to decontaminate all chemical deposited on the skin, and skin absorption can be enhanced by the wash-in effect. Other liquid solutions or systems as adsorbent powders, mobilizing agents, chelation therapy are also applied as decontaminants, but till nowadays does not exist a decontamination method which can be adopted in all situations. Therefore, there is an urgent need to develop more efficient and successful decontaminating formulations.

Development and Characterization of a Novel Hydrogel for the Decontaminating of Radionuclide-Contaminated Skin Wounds

Designing skin decontaminating materials with outstanding therapeutic effects, adhesiveness, and suitable mechanical property has great practical significance in radionuclide-contaminated skin wound healing. Here, a physically crosslinked hydrogel is constructed via hydrogen bonding of poly acrylamide, sodium alginate (SA), and the complexing agent diethylene triamine pentaacetic acid (DTPA). The physical and chemical properties of the poly(AAm-SA-DTPA) hydrogel (PASD) are detected according to established methods. The decontaminating property and skin wound healing of the PASD are investigated to confirm multi-functions of wound dressing. The physical and chemical properties results show that the synthesis of the PASD hydrogel is effective and that DTPA is present in the hydrogel. The hydrogel also shows great mechanical and swelling properties. In vitro tests find that PASD shows significant scavenging abilities for strontium and cerium. In vivo experiments show that the PASD hydrogel can remove radioactive strontium from the skin wounds of mice, and can effectively prevent the absorption of radioactive strontium through the skin wound. Furthermore, the PASD hydrogel can effectively promote the formation of granulation tissue in a radioactive contaminated wound. Taken together, the PASD hydrogels, which has good mechanical properties and radionuclides decontamination, is expected to be used as a dressing for radionuclide-contaminated skin wound healing.

Inorganic ions in the skin: Allies or enemies?

Skin constitutes a barrier protecting the organism against physical and chemical factors. Therefore, it is constantly exposed to the xenobiotics, including inorganic ions that are ubiquitous in the environment. Some of them play important roles in homeostasis and regulatory functions of the body, also in the skin, while others can be considered dangerous. Many authors have shown that inorganic ions could penetrate inside the skin and possibly induce local effects. In this review, we give an account of the current knowledge on the effects of skin exposure to inorganic ions. Beneficial effects on skin conditions related to the use of thermal spring waters are discussed together with the application of aluminium in underarm hygiene products and silver salts in treatment of difficult wounds. Finally, the potential consequences of dermal exposure to topical sensitizers and harmful heavy ions including radionuclides are discussed.