Tailorable Polymeric Assemblies Based on Host/Guest Interactions Between Modified Dextrans

Abstract

Nanoassemblies are spontaneously formed in dilute aqueous solutions by mixing of two dextrans modified with lauroyl and b-cyclodextrin moieties, respectively. This association process is mainly driven by host/guest interactions between the two polymers. The nanoassemblies' size depends on the substitution degrees of the polymers, and on the total concentration and composition of the mixtures. The results are compared to those previously obtained with adamantyl grafted dextrans. The number and the strength of the individual guest-host complexes between the two grafted dextrans is the key parameter to obtain small and stable nanoassemblies.

Formation of nanoparticles by cooperative inclusion between (S)-camptothecin-modified dextrans and β-cyclodextrin polymers

“…From the N 3 CPT two series of novel CPT-dextrans were synthesized by a copper(I)-catalyzed alkyne azide coupling (CuAAC). The dextrans were based on a 10 kDa and 70 kDa dextran backbone, respectively, which had been modified with alkynes by reaction with glycidyl propargyl ether (GP) as previously described [ 15 ]. The subsequent CuAACs with the alkyne-modified dextrans were made in DMSO using standard “click” conditions with 5 mol % Cu(I) compared to alkynes, stabilized with TBTA ( Scheme 2 ).…”

“…Ambersep GT74 resin, anhydrous dichloromethane (DCM) ≥99.8%, N -(3-dimethylaminopropyl)- N ′-ethylcarbodiimide hydrochloride (EDC) ≥99.0%, 4-(dimethylamino)pyridine (DMAP) ≥98%, anhydrous dimethyl sulfoxide (DMSO) ≥99.5%, sodium L-ascorbate (NaAsc) ≥98%, tetrakis(acetonitrile)copper(I) hexafluorophosphate (Cu(CH 3 CN) 4 PF 6 ) 97% were all from Sigma-Aldrich and were used as received. A β-CD-dextran polymer (D70HPβ-CD) was obtained by grafting 6-azido- O -deoxyβ-CD onto 70 kDa dextran modified by 7-heptynoic acid, in a similar way as described in literature [ 15 ]. The polymer contained 58.6% β-CD (w/w).…”

“…The advantages of CD polymers can be exploited in preparation of nanoparticles. It has been shown that CD polymers can form nanoparticles when associated with various amphiphilic polymers such as dextran modified with fatty acid chains [ 15 ] or adamantane [ 16 ] in aqueous solution. Simply by mixing solutions of β-CD polymers and the hydrophobic-modified dextrans with a degree of substitution between 4.7 and 9.1% nanoparticles with sizes between 100–400 nm are formed instantly.…”

“…The nanoparticle formation arises from inclusion formation between hydrophobic chains on the dextran and the CD moieties of the CD polymers. The vacant CD cavities in the nanoparticles can be loaded with hydrophobic molecules and are stable for several days [ 15 ].…”

Cyclodextrin-based supramolecular nanoparticles mediated by host-guest and electrostatic interactions: from self-assembly properties to biomedical applications

“…2.3). 64,65 As guest polymer they used Ad-grafted dextran polymers (Ad-Dextran). By using dextrans with different degrees of grafting, some degree of control over the size of the assemblies was achieved.…”