Biodegradable hyperbranched polyether-lipids with in-chain pH-sensitive linkages

Abstract

Hyperbranched polyether-based lipids with cleavable acetal units were obtained via copolymerization of the epoxide inimer 1-(glycidyloxy)ethyl ethylene glycol ether (GEGE) and glycidol, using anionic ring-opening polymerization.

Modular Functionalization of Laminarin to Create Value-Added Naturally Derived Macromolecules

“…Our characterizations are in accordance with those that have been reported ,, and were further expanded to include and confirm the modification of the produced derivatives (Figure ). Characteristically, the LAM–CC derivative displays three new chemical shifts on the corresponding 1 H NMR spectrum (Figure A; i.e.. a, b, and c at δ = 4.08, 5.30, and 5.97 ppm; substitution degree (SD) of around 47%) that result from the addition of an allyl group during the nucleophilic substitution process, which is corroborated by other works. − A similar trend is observed in the 13 C NMR spectra, specifically, the appearance of the signals at δ = 118.5 and 133.7 ppm that correspond to the new carbons present in the LAM–CC backbone. Interestingly, different SDs ranging from 5 to 47% can be obtained by tuning the amount of allyl bromide added to the chemical reaction mixture (Figure S1).…”

“…The successful modification of LAM–CC was also proven by 1 H NMR spectroscopy by the complete disappearance of the vinyl signals at δ = 5.97 and 5.24–5.36 ppm in combination with the appearance of new signals at δ = 1.88 and 2.68 ppm in all three modifications, also proving that the coupling was complete. − 13 C NMR spectroscopic analysis confirmed the disappearance of the allyl resonances and the appearance of two signals at δ = 27.3 and 28.2 ppm that correspond to the alkyl chain adjacent to the newly formed thioether in all three cases (Figure ). Further resonances attributed to the added functionality were also clearly observed and are in accordance with previously published studies .…”

Judging Enzyme-Responsive Micelles by Their Covers: Direct Comparison of Dendritic Amphiphiles with Different Hydrophilic Blocks

“…It is clear that DDS should be, on one hand, extremely stable to withstand the high dilution and interactions with blood components in order to allow their circulation in the body while maintaining their cargo of active drug molecules . On the other hand, the carriers should be able to release the drugs when the DDS has reached the target site. − To address this need, over the last three decades, there has been a great interest in utilizing stimuli-responsive polymeric micelles as DDS to allow selective release of their therapeutic cargo. , There are many reported examples of polymeric micelles that disassemble due to changes in pH, − temperature, − or redox potential, − while there are significantly fewer examples of polymeric nanocarriers that can disassemble due to the presence of a designated enzyme. − Enzymes are very appealing for triggering the disassembly of drug containing micelles since they are already present in the body, known for their high substrate specificity and in many cases specific enzymes are overexpressed in diseased tissues. − Polymeric micelles are typically formed by the self-assembly of amphiphilic diblock copolymers so that the hydrophobic block forms the core and the hydrophilic block forms the micellar corona. It is clear that in the biological environment, most of the interactions between the micelle and its surroundings occur through the micelle’s corona. , It is interesting to note that although most reported DDS are based on poly­(ethylene glycol) (PEG), , the use of additional types of promising hydrophilic polymers such as poly­(2-oxazoline)­s − and polyacrylates has also been reported, inspired by the increasing human population that carries anti-PEG antibodies leading to an immune-response upon treatment with PEG-based therapeutics. , To allow the rational design of DDS, it is critical to compare and study the behavior of different corona forming polymers in order to rationally select the most suited hydrophilic block .…”

Acetal‐Based Functional Epoxide Monomers: Polymerizations and Applications

“…The unique pH‐responsive degradation behavior of the GEGE inimer has been further demonstrated in a drug delivery system. [ 57 ] Lipid‐like macromolecules possessing a cholesterol head group with a degradable hyperbranched polymer tail have been produced using cholesterol as the initiator and glycidol and GEGE as the monomers (Figure 9c). Lipid‐like macromolecules possessing a cholesterol head group with a degradable hyperbranched polymer tail have been produced using cholesterol as the initiator and the glycidol and GEGE as the monomers (Figure 9c).…”