Pharmacologically active polymers, 23. Linear and branched zwitterionic derivatives of polyethyleneimine as carriers for pharmacologically active components

Abstract

To obtain a carrier polymer for pharmacologically active components, linear polyethyleneimine (LPEI) was chemically modified by reactions with acrylic acid (la), acrylamide (lb), acrylic acid esters ( l c and Id), sodium chloroacetate, and hydrochloric acid. All product polymers 2 a -2 e are soluble in water. Among these, 2a and 2e, band a-amino acid derivatives, respectively, show no acute toxicity in mice up to dosages of 1 g/kg i.v. Similar types of polymers 5 a and 5 b and a polymer containing phosphonic acid moieties (5d) derived from branched polyethyleneimine (BPEI) were prepared. 5a and 5 b are also nontoxic regardless of the molecular weight of four kinds of BPEI and of the wide range of carboxylic group content in the polymer. It is suggested that the zwitterion form contributes to the nontoxic nature of b-and a-amino acid type polymers. The present results show that amino acid type polymers derived from LPEI and BPEI can be used as carrier polymers for pharmacologically active components.

Structure of water in the vicinity of amphoteric polymers as revealed by Raman spectroscopy

“…Previously, it was found that linear and branched polyethyleneimines modified with acrylic acid showed no acute toxicity in mice up to dosage of 1 g/kg [95]. The zwitterionic form was attributed to the non-toxic nature of the amino acid type polymers, supporting the tendency observed in this work.…”

Fabrication of high‐mobility n ‐type carbon nanotube thin‐film transistors on plastic film

“…On the other hand, the current degradation was suppressed in the vacuum (blue). Because PEI is the material stable in air but also hydroscopic [47], the instability of the device in the air would be attributed to the water adsorbed in PEI. The passivation layer is necessary to improve the stability of PEI-doped devices.…”

Cyclic Imino Ethers, Polymerization

“…Of the products, only the α-and β-amino acid-type polymers are nontoxic; a zwitterion form (50), where m = 1, 2, in vivo may be responsible (110). (51) R = H (52) R = CH 2 CH 2 CO 2 Na (53) R = CH 2 CO 2 Na (54) R = CH 2 CH 2 SH (55) R = CS 2 Na CH 2 NC R H 2 CH 2 n Polymers (51)-(55) are good chelating resins.…”