Recensione

Bibliografia__________________________________________________________________________

Pontoriero G, Pozzoni P, Andrulli S, Locatelli F. The quality of dialysis water. Nephrol Dial Transplant. 2003 Aug;18 Suppl 7:vii21-5; discussion vii56. doi: 10.1093/ndt/gfg1074. 

Abstract. Introduction: Every week, haemodialysis patients are exposed to approximately 400 l of water used for the production of dialysis fluids which, albeit with the interposition of a semi-permeable artificial membrane, come into direct contact with the bloodstream. It is therefore clearly important to know and monitor the chemical and microbiological purity of dialysis water. Methods: In this review, we analyse the sources of chemical and microbiological water contamination, and the problems involved in water purification systems and modalities. We also analyse the compliance of dialysis units with the microbiological standards established by the most widely accepted guidelines relating to the quality of dialysis fluids. Results: The risk of chemical contamination is due mainly to the primary pollution of municipal water, whereas the most important microbiological problem is the control of bacterial growth in the water treatment and distribution system. Dialysis water treatment implies various levels of pre-treatment, a final purification module (which, in many cases, is reverse osmosis: RO) and a hydraulic circuit for the distribution of the purified water. RO-based treatment systems produce water of optimal chemical and microbial quality, and so dialysis units need to concentrate on maintaining this quality level in the long term by means of effective maintenance and disinfection strategies. The most widely accepted standards for water purity are those recommended by the Association for the Advancement of Medical Instrumentation and the European Pharmacopea, which respectively allow bacterial growth of <200 and <100 c.f.u./ml, and an endotoxin concentration of <2 and <0.25 IU/ml. However, a number of multicentre studies have reported that 7-35% of water samples have bacterial growth of >200 c.f.u./ml, and up to 44% have endotoxin levels of >5 IU/ml. Conclusions: The results of multicentre studies indicate that the microbial quality of dialysis fluids is still a too often neglected problem, particularly as there is evidence of a possible relationship between dialysis fluid contamination and long-term morbidity. The time has now come to take advantage of innovations in water treatment processes and improvements in dialysis machines in order to modify clinical practices and start improvement processes aimed at decreasing the risk of microbial contamination to the minimum, as it has already been successfully done in the case of chemical contamination.

Mabic S, Kano I. Impact of purified water quality on molecular biology experiments. Clin Chem Lab Med. 2003 Apr;41(4):486-91. doi: 10.1515/CCLM.2003.073.

Abstract. Purified water is a reagent used in a variety of molecular biology experiments, for sample and media preparation, in mobile phases of liquid chromatography techniques, and in rinsing steps. The combination of several technologies in water purification systems allows delivering high-purity water adapted to each application and technique. Through a series of examples, the importance of water quality on biotechnology experiments, such as single nucleotide polymorphism (SNP) analysis by denaturating HPLC, RNA preparation and PCR, is presented. Results obtained on DNA mutation and single nucleotide polymorphism analysis using the denaturating HPLC (DHPLC) technique highlight the benefits of organic removal by UV photooxidation process. Comparative gel electrophoresis data show that ultrafiltration is as efficient as diethylpyrocarbonate (DEPC) treatment for suppressing RNase activity in water. Gel electrophoresis and densitometry measurement also point out the benefits of ultrafiltration to carry out reverse transcriptase-polymerase chain reaction quantitatively.

Anindita De, Singh NB, Guin M, Barthwal S. Water Purification by Green Synthesized Nanomaterials. Curr Pharm Biotechnol. 2023;24(1):101-117. doi: 10.2174/1389201023666220507030548. PMID: 35524657.

Marius M, Vacher F, Bonnevay T. Comparison of bacterial endotoxin testing methods in purified pharmaceutical water matrices. Biologicals. 2020 Sep;67:49-55. doi: 10.1016/j.biologicals.2020.07.001. Epub 2020 Aug 2. PMID: 32753293.

Tsompou A, Kocherbitov V. The effects of water purity on removal of hydrophobic substances from solid surfaces without surfactants. J Colloid Interface Sci. 2022 Feb 15;608(Pt 2):1929-1941. doi: 10.1016/j.jcis.2021.10.040.