AND POLYMERIC MATERIALS
Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 3, pp. 426−431.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © M.V. Solovskii, M.Yu. Smirnova, A.I. Amirova, E.B. Tarabukina, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 3,
Synthesis of Low-Molecular-Weight
N-(2-Hydroxypropyl)methacrylamide Sulfonated Copolymers
as Carriers of Biologically Active Substances
M. V. Solovskii, M. Yu. Smirnova, A. I. Amirova, and E. B. Tarabukina
Institute of Macromolecular Compounds, Russian Academy of Sciences, St. Petersburg, Russia
Received May 16, 2011
Abstract—New water-soluble copolymers of N-(2-hydroxypropyl)methacrylamide with 2-acrylamido-2-methyl-
propanesulfonic acid as carriers of cationic biologically active substances were synthesized. The physicochemical
properties of the copolymers were studied.
Biocompatible water-soluble reactive copolymers
of N-(2-hydroxypropyl)methacrylamide (HPMA)
with acrylic acid and with p-nitrophenyl esters of
unsaturated phenoxyacetic acids and of N-methacryloyl
oligopeptide derivatives are widely used as carriers for
various biologically active substances (BASs): enzymes,
hormones, or antibiotics [1–7].
The goal of this study was to synthesize new
sulfonated copolymers of HPMA with 2-acrylamido-
2-methylpropanesulfonic acid (AAMPSA) (I)
as polymeric BAS carriers and to examine their
composition, molecular weights, and physicochemical
m + n = 100 mol %.
Copolymers I contain two reactive groups: OH
groups in HPMA units and SO
H groups in AAMPSA
units. Through these units, it is possible to link several
BASs with different mechanisms of biological action
and to obtain polymers with polyfunctional activity.
Copolymers I were synthesized by copolymerization
of HPMA with AAMPSA in ethanol or 2-propanol
at 65°С with 2,2'-azobis(isobutyronitrile) (AIBN) as
initiator. The results of copolymerization experiments
are given in Table 1. As follows from Table 1 (run
no. 3), the copolymerization in 2-propanol (agent
known to transfer the propagating polymer chain) at
low concentration of the starting monomer mixture
(10 wt %) and high initiator concentration (4.5 wt %)
yields a high-molecular-weight nonbiodegradable
copolymer with MW 52000 Da. At the concentration
of the starting monomers decreased to 5.0 wt % (run
no. 4), the copolymer with M
= 26000 Da was obtained,
though in a low yield, 58.2%. In the subsequent
experiments (run nos. 5–10), the copolymerization of
HPMA with AAMPSA was performed in the presence
of mercaptoethanol as chain-transfer agent. Comparison
of the results (run nos. 3, 5) shows that the presence of
0.2 wt % mercaptoethanol in the starting reaction mixture
leads to a decrease in the MW of the copolymer formed
from 52000 to 30000 Da, under equal other conditions.
An increase in the mercaptoethanol amount in the starting