Ways in which Synthetic Polymers Cross Compartmental Barriers

2 Ways in which Synthetic Polym s Cross Compartmental Barriers 

The distribution of a polymer in the body, the rate of its clearance, the site and time duration of its retention, i.e., all the basic factors determining the availability of a medical polymer for biological activity may be understood as resulting from its partitioning at compartmental barriers. These particular barriers may have various compositions (see below) but mostly thrir crossing includes some means of crossing of a biological membrane, which will be briefly characterized below. 

The transport of low-molecular weight compounds (water, ions) is not accompanied by any virible morphological changes. It proceeds by passive diffusion or an active transport process, depending on the polarity and size of the transported molecule and presence of a specific carrier protein in the membrane. Water-soluble polymers 

3a and b. Fluid mosaic structure of the cell membrane, a Overall representation 1 — talayer of hpid molecules 2 — membrane proteins, including receptors, membrane transport proteins, proteins mediating signal transfer etc. 3 — polysaccharide layer — glycocalyx b molecular structure of the lipid bilayer a — cholesterol b — lateral chains of fatty acids c — glycCTol residue d — phosphate moiety of the phospholipid molecule e — positively charged (amino) part of the pho holipid molecule (From Refs. 

---