Gelating polypeptide matrices based on the difunctional N‐carboxyanhydride diaminopimelic acid cross‐linker

Abstract

This work reports the synthesis of a new difunctional N-carboxyanhydride (NCA) monomer, namely diaminopimelic acid (DAP), and its use in the one-pot preparation of an organogelating copolypeptide. The organogel is formed in situ through ring-opening polymerization (ROP) of DAP NCA from helical poly(ε-carbobenzyloxy-L-lysine) (PZLL) blocks in a mixture of dimethylformamide/chloroform. Gelation occurs by immobilizing the solvent through core crosslinking and is stabilized through physical intermolecular conformations. After removal of the carbobenzyloxy (cbz or Z) protecting groups, the network remains intact in exceedingly high aqueous concentrations (99.5%). FTIR is used to characterize the secondary structure, revealing the conformational arrangements that contributed to these stabilized gel networks with their relative mechanical properties determined via real-time rheological assays. DAP core crosslink of the random coil forming polypeptoid poly(sarcosine) (PSar) is also resulting in networks but is devoid of any stabilized physical interactions, thus yielding significantly weaker gels as a result.

From gas release to foam synthesis, the second breath of blowing agents

“…Several studies have been carried out using the ROP between 0°C and room temperature, where the ROP of NCA is usually initiated with a primary amine. For example, Murphy et al presented the ROP initiated with allylamine 135 . Sulistio et al presented the ROP for dendrimer synthesis.…”

pH-Responsive, Thermoset Polymer Coatings for Active Protection against Aluminum Corrosion

“…One solution to this issue would be through the use of amine-protecting groups, where deprotection (and concomitant liberation of the basic amine group) occurs under the conditions of filiform corrosion (i.e., pH ∼ 1.0–2.5). The tert -butylcarbamate (BOC) protecting group is widely used in the fine chemical and pharmaceutical industries as an acid-labile protecting group for amines − but to the best of our knowledge has never been studied in coatings for pH-responsive corrosion prevention (Figure ). The use of this functional group may open opportunities to create multifunctional, pH-responsive polymers capable of both forming thermoset coatings and preventing propagation of FFC on aluminum substrates.…”

Self-Assembling Oligo(2-oxazoline) Organogelators for the Encapsulation and Slow Release of Bioactive Volatiles

“…Supramolecular organogels have been attracting considerable attention over the last decades owing to their prospective and realized applications in numerous fields such as food, , cosmetics, drug delivery, − encapsulation and controlled release of fragrance, and advanced materials. − This kind of physical gel is generally formed by immobilizing organic solvents and oils in a three-dimensional network created by the entanglement of noncovalently self-assembled nanofibers. , Among many known gelators, peptidomimetic oligomers and polymers with secondary structures are particularly attractive gel-forming materials due to their intrinsic self-assembly propensity to hierarchically ordered architectures as well as the potential advantages like biocompatibility and bioactivity. , Previous studies have demonstrated that synthetic polypeptides − or peptide-containing block copolymers − exhibited good gelling activity in appropriate organic solvents in which a rigid α-helical or β-sheet motif plays a critical role in the formation of fibrillar networks. ,,,− …”