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Polymeric nanoparticles containing multiple amines and carboxylates have been frequently used in drug delivery research. Reproducible and controlled conjugation among these multifunctional biomaterials is necessary to achieve efficient drug delivery platforms. However, multiple functional groups increase the risk of unintended intramolecular/intermolecular reactions during conjugation. Herein, conjugation approaches and possible undesired reactions between multi-amine functionalized peptides, multi-carboxylate functionalized polymers, and anhydride-containing polymers [Poly(styrene-alt-maleic anhydride)-b-poly(styrene)] were investigated under different conjugation strategies (carbodiimide chemistry, anhydride ring-opening via nucleophilic addition elimination). Muti-amine peptides led to extensive crosslinking between polymers regardless of the conjugation chemistry. Results also indicate that conventional peptide quantification methods (i.e., o-phthalaldehyde assay, bicinchoninic acid assay) are unreliable. Gel permeation chromatography (GPC) provided more accurate qualitative and quantitative evidence for intermolecular crosslinking. Crosslinking densities were correlated with higher feed ratios of multifunctional peptides and carbodiimide coupling reagents. Selectively protected peptides (Lys-Alloc) exhibited no crosslinking and yielded peptide-polymer conjugates with controlled dispersity and molecular weight. Furthermore, anhydride ring-opening (ARO) nucleophilic addition elimination was successfully introduced as a facile yet robust peptide conjugation approach for cyclic anhydride-containing polymers.
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Amination of polypropylene‐ g ‐(maleic anhydride) using reactive extrusion
Abstract We report synthesis of a radical scavenging aminated thermoplastic polymer through reactive extrusion of polyethyleneimine (PEI) with a polypropylene and polypropylene‐graft‐maleic anhydride (PP‐g‐MA) meltblend. The reaction was confirmed using acid orange 7 (AO7) amine density assay, toluidine blue O (TBO) carboxylic acid density assay, Fourier transform infrared spectroscopy (FTIR), and a migration assay. FTIR spectra revealed a reduction of the asymmetric stretching of the maleic anhydride (MA) carbonyl group at 1777 cm−1and the emergence of the maleimide carbonyl peak at 1702 cm−1. AO7 supported surface orientation of grafted amine groups by introduction of 7.22 nmol cm−2primary amines, corresponding to the reduction of surface carboxylic acids quantified by TBO from 12.46 nmol cm−2to 0.43 nmol cm−2. After incubation (40°C, 10 days) in ethanol, acetic acid, and water, < 0.1 mg cm−2PEI migrated from the materials, supporting the covalent nature of the grafting. Antioxidant activity was demonstrated exhibiting 5.90 and 4.31 nmol Troloxeqcm−2in aqueous and organic environments, respectively. Results indicate a successful condensation reaction during reactive extrusion, producing an aminated thermoplastic polymer with antioxidant activity for target applications such as food packaging, wastewater treatment, carbon capture, and others.
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- Award ID(s):
- 1719875
- PAR ID:
- 10548688
- Publisher / Repository:
- Wiley Online Library
- Date Published:
- Journal Name:
- Journal of Applied Polymer Science
- Volume:
- 141
- Issue:
- 41
- ISSN:
- 0021-8995
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/app.56085
