Polymethylsiloxane polyhydrate

Polymethylsiloxane polyhydrate (PMSPH) is a material use for sorption detoxification. It acts as sorbent for binding toxic substances of various natures, pathogens and metabolites in the gastrointestinal tract and their excretion. PMSPH is a homogeneous paste-like mass of white or almost white color, odorless.

History

PMSPH was first synthesized in the late 1970s in the Institute of physical chemistry named after L.V. Pisarzhevsky in Kyiv (I.B. Slinyakova, I.M. Samodumova).[1] That work was based on earlier work there developing theories for the formation of porous structure of organosilicon adsorbents with adjustable pore structure and chemical nature of a given surface and studies on synthesis of organosilicon adsorbents.

General information

Polymethylsiloxane polyhydrate is a gelly-like polymeric organosilicon compound. The gel is dispersed in water to a particle size less than 300 microns in suspension.

Microstructure

Electron microscopical studies have revealed that the gel-forming matrix has a globular structure and consists of an ensemble of fused globules. The globules bound with siloxane linkages form pores.[2] The pores are spaces between the globules filled with water. The pore sizes are restricted. Sorption isotherms for hexane and methanol show that the adsorbent has a mesoporous structure.[2][3] Presence of methyl groups on the surface provides their hydrophobic properties.[4] PMSPH particles tend to form a continuous network in the suspension to reduce interaction of the hydrophobic groups SiCH3 with water. These particles can be viewed as 2D sheets rather than 3D solids. Aqueous suspensions of polymethylsiloxane polyhydrate are characterized by high viscosity.[5]

Mechanism of action

PMSPH is not absorbed in the gastrointestinal tract and is excreted unchanged within 12 hours. A robust porous structure of the gel-forming matrix determines absorptive capacity of the mechanism of molecular adsorption and allows mostly to adsorb toxic substances and metabolites (e.g., bilirubin, protein breakdown products).[6] Thanks to its gelly-like consistency, PMSPH:

  • absorbs macromolecular toxic substances by a mechanism of precipitation in the gel (e.g., bacterial toxins);[7]
  • exhibits protective properties - elastic gelly-like drug particles form a layer on the mucosal surfaces.[5] This layer protects the mucous membranes from exposure to various damaging factors, while its protective properties are manifested universally - in the intestine and on the mucosal surface of other organs.[8]

PMSPH absorbs toxic substances from the gastrointestinal tract as well as toxic substances (xenobiotics) trapped in the gastro-intestinal tract, from the surrounding environment. PMSPH also prevents reabsorption of toxins and metabolites spun into the lumen of the blood as well as transferred to the intestine with bile. PMS PH firmly binds and removes pathogenic bacteria.[9] PMSPH possesses a pronounced ability to absorb lipopolysaccharide molecules.[10] Large lipopolysaccharide molecules coprecipitate in the gel and are excreted. A daily dose of PMSPH binds 410 mg of Lipopolysaccharide (LPS),[2] which has an extremely high biological activity. LPS can be found in the outer wall of gram-negative bacteria and is released only when the bacteria are destroyed, hence it is also called endotoxin (endo means "inside", inside the bacteria). The main reservoir of gram-negative microflora and lipopolysaccharide is the distal intestine.[11] Effectiveness of Enterosgel was proven in trials.[12][13] PMSPH is used in medicine [14] [15] [16] [17] [18] [19] [20] [21]

Notes

Bibliography

  • Grek, O. R.; Mishenina, S. V.; Pupyshev, Y.K.; et al. (2002). "Protective Effect of Enterosgel on Rat Liver lysosomes during Cytostatic treatment". Bulletin of Experimental Biology and Medicine. 134 (4): 355–358. doi:10.1023/A:1021904230328.
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