Molecular weight distribution and endgroup functionality of poly(2-ethyl-2-oxazoline) prepolymers

Celebi, O.; Barnes, S.R.; Narang, Gurtej S.; Kellogg, David R.; Mecham, Sue J.; Riffle, Judy S.

doi:10.1016/j.polymer.2014.11.005

Cited by 7 publications

(7 citation statements)

References 43 publications

(32 reference statements)

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“…Blank PEtOx NPs showed decomposition in between 245–365°C with 70% weight loss. However, CIP-loaded PEtOx NPs showed up to 57% weight loss until 527°C which suggests the possible interaction among PEtOx, TA, and CIP [ 40 ]. The amount of CIP in the formulations also showed crucial characteristics in the thermal behaviour of the NPs.…”

Section: Resultsmentioning

confidence: 99%

Inhaled ciprofloxacin-loaded poly(2-ethyl-2-oxazoline) nanoparticles from dry powder inhaler formulation for the potential treatment of lower respiratory tract infections

et al. 2021

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Lower respiratory tract infections (LRTIs) are one of the fatal diseases of the lungs that have severe impacts on public health and the global economy. The currently available antibiotics administered orally for the treatment of LRTIs need high doses with frequent administration and cause dose-related adverse effects. To overcome this problem, we investigated the development of ciprofloxacin (CIP) loaded poly(2-ethyl-2-oxazoline) (PEtOx) nanoparticles (NPs) for potential pulmonary delivery from dry powder inhaler (DPI) formulations against LRTIs. NPs were prepared using a straightforward co-assembly reaction carried out by the intermolecular hydrogen bonding among PEtOx, tannic acid (TA), and CIP. The prepared NPs were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction analysis (PXRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The CIP was determined by validated HPLC and UV spectrophotometry methods. The CIP loading into the PEtOx was between 21–67% and increased loading was observed with the increasing concentration of CIP. The NP sizes of PEtOx with or without drug loading were between 196–350 nm and increased with increasing drug loading. The in vitro CIP release showed the maximum cumulative release of about 78% in 168 h with a burst release of 50% in the first 12 h. The kinetics of CIP release from NPs followed non-Fickian or anomalous transport thus suggesting the drug release was regulated by both diffusion and polymer degradation. The in vitro aerosolization study carried out using a Twin Stage Impinger (TSI) at 60 L/min air flow showed the fine particle fraction (FPF) between 34.4% and 40.8%. The FPF was increased with increased drug loading. The outcome of this study revealed the potential of the polymer PEtOx as a carrier for developing CIP-loaded PEtOx NPs as DPI formulation for pulmonary delivery against LRTIs.

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Section: Resultsmentioning

confidence: 99%

Inhaled ciprofloxacin-loaded poly(2-ethyl-2-oxazoline) nanoparticles from dry powder inhaler formulation for the potential treatment of lower respiratory tract infections

et al. 2021

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“…Initially, monomer conversions were measured using 1 H NMR spectroscopy and obtained from the integral ratios of resonances corresponding to each monomer and its polymer backbone (–CH 2 CH 2 –). 51 1 H NMR spectra for all monomers are shown in Fig. 2 and individual shifts for each monomer given in ESI (Section 3 † ) were assigned according to literature.…”

Section: Resultsmentioning

confidence: 99%

Copolymer chain formation of 2-oxazolines by in situ¹H-NMR spectroscopy: dependence of sequential composition on substituent structure and monomer ratios

et al. 2021

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“…From a retrosynthetic point of view, the utilization of a bifunctional CROP initiator featuring a protected functional moiety could serve this purpose. Although bifunctional initiators have been utilized in the cationic ring‐opening polymerization (CROP) of 2‐oxazolines, [ 18–22 ] additional functional moieties enabling peptide attachments are, to the best of our knowledge, missing up to now.…”

Section: Introductionmentioning

confidence: 99%

Poly(2‐ethyl‐2‐oxazoline) Featuring a Central Amino Moiety

Dirauf

Fritz

Gottschaldt

et al. 2021

Macromol. Rapid Commun.

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The incorporation of an amino group into a bifunctional initiator for the cationic ring‐opening polymerization (CROP) is achieved in a two‐step reaction. Detailed kinetic studies using 2‐ethyl‐2‐oxazoline demonstrate the initiators’ eligibility for the CROP yielding well‐defined polymers featuring molar masses of about 2000 g mol–1. Deprotection of the phthalimide moiety subsequent to polymerization enables the introduction of a cyclooctyne group in central position of the polymer which is further exploited in a strain‐promoted alkyne‐azide click reaction (SpAAC) with a Fmoc‐protected azido lysine representing a commonly used binding motif for site specific polymer–protein/peptide conjugation. In‐depth characterization via electrospray ionization mass spectrometry (ESI) confirms the success of all post polymerization modification steps.

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Molecular weight distribution and endgroup functionality of poly(2-ethyl-2-oxazoline) prepolymers

Cited by 7 publications

References 43 publications

Inhaled ciprofloxacin-loaded poly(2-ethyl-2-oxazoline) nanoparticles from dry powder inhaler formulation for the potential treatment of lower respiratory tract infections

Inhaled ciprofloxacin-loaded poly(2-ethyl-2-oxazoline) nanoparticles from dry powder inhaler formulation for the potential treatment of lower respiratory tract infections

Copolymer chain formation of 2-oxazolines by in situ¹H-NMR spectroscopy: dependence of sequential composition on substituent structure and monomer ratios

Poly(2‐ethyl‐2‐oxazoline) Featuring a Central Amino Moiety

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Molecular weight distribution and endgroup functionality of poly(2-ethyl-2-oxazoline) prepolymers

Cited by 7 publications

References 43 publications

Inhaled ciprofloxacin-loaded poly(2-ethyl-2-oxazoline) nanoparticles from dry powder inhaler formulation for the potential treatment of lower respiratory tract infections

Inhaled ciprofloxacin-loaded poly(2-ethyl-2-oxazoline) nanoparticles from dry powder inhaler formulation for the potential treatment of lower respiratory tract infections

Copolymer chain formation of 2-oxazolines by in situ1H-NMR spectroscopy: dependence of sequential composition on substituent structure and monomer ratios

Poly(2‐ethyl‐2‐oxazoline) Featuring a Central Amino Moiety

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Copolymer chain formation of 2-oxazolines by in situ¹H-NMR spectroscopy: dependence of sequential composition on substituent structure and monomer ratios