DNA adsorption on poly(N,N‐dimethylacrylamide)‐grafted chitosan hydrogels

Abstract

In this study, poly(N,N-dimethylacrylamide) grafted chitosan (PDMAAm-g-CT) hydrogels were prepared for deoxyribonucleic acid (DNA) adsorption. Instead of directly grafting the N,N-dimethylacrylamide (DMAAm) monomer onto the chitosan (CT) chains, poly(N,N-dimethylacrylamide) with carboxylic acid end group (PDMAAm-COOH) was firstly synthesized by free-radical polymerization using mercaptoacetic acid (MAAc) as the chain-transfer agent and then grafted onto the CT having amino groups. The synthesis of PDMAAm-COOH and its grafting onto the CT chains were confirmed by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. From gel permeation chromatography measurements, the numberaverage molecular weight (M n ) and polydispersity index of PDMAAm-COOH were found as 2400 g/mol and 2.3, respectively. The PDMAAm-g-CT hydrogels were utilized as the adsorbents in DNA adsorption experiments conducted at þ4 C in a trisEDTA solution of pH 7.4. The hydrogels produced with higher PDMAAm-COOH content exhibited higher DNA adsorption capacity. The DNA adsorption capacity up to 4620 lg DNA/g dry gel could be achieved with the PDMAAm-g-CT hydrogels prepared in 80.0 wt % PDMAAm-COOH feed concentration. This value is approximately seven times higher than that of CT alone.

Surface modification of electrospun cellulose acetate nanofibers via RAFT polymerization for DNA adsorption

“…Moreover, the Langmuir equation fits well for DNA immobilization on the poly(VBTAC)-g-CA web under the concentration range studied. Adsorption capacity of some solid surfaces was previously investigated as detailed elsewhere (Baser et al, 2011;Rahman & Alaissari, 2011). Compared to solid surfaces, poly(VBTAC)-g-CA nanofibrous web showed higher adsorption capacity.…”

“…In our previous study, we also showed that cationic polymer brushes can be used for quantitative DNA adsorption . But, all of these materials, especially polymer coated solid surfaces have low adsorption capacity, because of the low surface area (Baser, Demirel, & Caykara, 2011;Rahman & Alaissari, 2011).…”

Living radical polymerization of acrylates and acrylamides mediated by a versatile cobalt porphyrin complex

“…The (TMP-OH)Co system is the first cobalt complex reported to mediate a living radical polymerization of acrylamide, and the LRP process in methanol has been extended to a series of water soluble monomers including N-isopropylacrylamide (NIPAM), 2-hydroxyethyl acrylate (HEA), and acrylic acid (AA). The resulting polymers PNIPAM, PHEA and PAA show narrow molecular weight distributions (M w /M n E 1.3) and desired molar mass (Table 1, entries [15][16][17][18][19][20]. This class of water soluble monomers with polar functional groups has unusual properties that are useful particularly in biomedical applications.…”

“…The most important lower critical solution temperature (LCST) polymer is PNIPAM which has a robust transition close to body temperature; 11 PHEA produces biocompatible thermo-responsive copolymers; 12,13 PAA is good bio-application material in protein stabilizing 14 and drug loading; 15 and PDMA is receiving substantial attention because of the capability of forming hydrogels 16,17 and separation of peptides 18 and DNA. 19,20 A particularly important feature of (TMP-OH)Co is its solubility in both polar and non-polar solvents which gives direct routes to prepare well defined block copolymers with a substantial range of functional groups. Representative block copolymers prepared using (TMP-OH)Co as the mediator are shown in Table 2.…”