Fast-forward approach of time-domain NMR relaxometry for solid-state chemistry of chitosan

Facchinatto, William Marcondes; Garcia, Rodrigo Henrique dos Santos; Santos, Danilo Martins dos; Fiamingo, Anderson; Flores, Douglas William Menezes; Filho, Sérgio Paulo Campana; Azevêdo, Eduardo Ribeiro de; Colnago, Luiz Alberto

doi:10.1016/j.carbpol.2020.117576

Cited by 7 publications

(3 citation statements)

References 67 publications

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“…As a consequence, a linear relationship was built up using the integral ratios

and

( Supplementary Materials ) with

( Figure 1 g,h), showing a high coefficient of determination (R 2 > 0.98). Similarly to our previous findings [ 53 ], FT-Raman also figures as a fast and reliable spectroscopy technique, capable of predicting structural features of chitosan.…”

Section: Resultssupporting

confidence: 84%

“…The preparation process and structural characterization of low-molecular-weight chitosans (Ch) have already been detailed in our previous studies [ 51 , 53 ]. In brief, allomorph β-chitin, extracted from squid pens of Doryteuthis spp., was submitted to an ultrasound-assisted deacetylation process (USAD) under strong alkaline conditions, leaving a first chitosan sample named Ch1× as the main product.…”

Section: Methodsmentioning

confidence: 99%

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Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites

Facchinatto

Araujo

Moraes

et al. 2022

IJMS

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Multidrug-resistant bacteria represent a global health and economic burden that urgently calls for new technologies to combat bacterial antimicrobial resistance. Here, we developed novel nanocomposites (NCPs) based on chitosan that display different degrees of acetylation (DAs), and conjugated polymer cyano-substituted poly(p-phenylene vinylene) (CNPPV) as an alternative approach to inactivate Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria. Chitosan’s structure was confirmed through FT-Raman spectroscopy. Bactericidal and photobactericidal activities of NCPs were tested under dark and blue-light irradiation conditions, respectively. Hydrodynamic size and aqueous stability were determined by DLS, zeta potential (ZP) and time-domain NMR. TEM micrographs of NCPs were obtained, and their capacity of generating reactive oxygen species (ROS) under blue illumination was also characterized. Meaningful variations on ZP and relaxation time T2 confirmed successful physical attachment of chitosan/CNPPV. All NCPs exhibited a similar and shrunken spherical shape according to TEM. A lower DA is responsible for driving higher bactericidal performance alongside the synergistic effect from CNPPV, lower nanosized distribution profile and higher positive charged surface. ROS production was proportionally found in NCPs with and without CNPPV by decreasing the DA, leading to a remarkable photobactericidal effect under blue-light irradiation. Overall, our findings indicate that chitosan/CNPPV NCPs may constitute a valuable asset for the development of innovative strategies for inactivation and/or photoinactivation of bacteria.

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“…As a consequence, a linear relationship was built up using the integral ratios

and

( Supplementary Materials ) with

Section: Resultssupporting

confidence: 84%

Section: Methodsmentioning

confidence: 99%

Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites

Facchinatto

Araujo

Moraes

et al. 2022

IJMS

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“…In the last decades, there has been a remarkable development of low cost, low magnetic field ( B 0 < 0.7 T), and low resolution (Δ B 0 > 100 ppm), benchtop, time-domain NMR (TD-NMR) relaxometry based on the permanent magnet (cryogenics free) is ideal for QC and QA of materials in the manufacturing process . These benchtop instruments have been widely used in food, agricultural, cosmetics, chemical, petrochemical, petroleum, and polymer industries; nevertheless, their use is still rare in QC and QA in the pharmaceutical industry …”

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confidence: 99%

NMR Longitudinal Rotating Frame Relaxation Time (T_1ρ) with a Weak Spin Locking Field as an Approach to Characterize Solid-State Active Pharmaceutical Ingredients: Proof of Concept

Almeida,

Garcia,

Ticona

et al. 2024

Anal. Chem.

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Nuclear magnetic resonance (NMR) longitudinal rotating frame relaxation time (T1ρ), rarely used in low-field NMR, can be more effective than conventional T1 and T2 relaxation times to differentiate polymorphic forms of solid pharmaceuticals. This could be attributed to T1ρ sensibility to structural and molecular dynamics that can be enhanced by changing the strength of the oscillating magnetic field (B 1 ) of spinlock pulses. Here, we compared the capacity of T1, T2, and T1ρ to differentiate inactive (A) and active (C) crystalline forms of the World Health Organization essential drug Mebendazole. The results showed that T1 and T2 values of both forms were statistically identical at 0.47 T. Conversely, T1ρ of both forms measured with weak spinlock B 1 fields, ranging from 0.08 to 0.80 mT were statistically different in the same spectrometer. The T1ρ also has the limit of detection to detect the presence of at least 10% of inactive A form in the active C form. Therefore, T1ρ, measured with weak spinlock B 1 fields can be an effective, streamlined, and complementary approach for characterizing not only solid active pharmaceutical ingredients but other solid-state materials as well.

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Solid‐State NMR Spectroscopy

Wang¹,

Yan²,

Li³

et al. 2022

Encyclopedia of Polymer Science and Technology

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Solid‐state NMR spectroscopy is an indispensable tool for probing detailed structures and dynamics of polymers at an atomic level due to its capability to selectively manipulate various types of anisotropic spin interactions in solids and its nondestructive property. Herein, this article mainly describes the properties of those anisotropic spin interactions in solids, and how they are used to extract structural and dynamic information via sophisticated one‐ and multidimensional solid‐state NMR spectroscopy. We hope this article can be a good tutorial for the researchers interested in using solid‐state NMR to study polymers.

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Fast-forward approach of time-domain NMR relaxometry for solid-state chemistry of chitosan

Cited by 7 publications

References 67 publications

Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites

Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites

NMR Longitudinal Rotating Frame Relaxation Time (T_1ρ) with a Weak Spin Locking Field as an Approach to Characterize Solid-State Active Pharmaceutical Ingredients: Proof of Concept

Solid‐State NMR Spectroscopy

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Fast-forward approach of time-domain NMR relaxometry for solid-state chemistry of chitosan

Cited by 7 publications

References 67 publications

Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites

Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites

NMR Longitudinal Rotating Frame Relaxation Time (T1ρ) with a Weak Spin Locking Field as an Approach to Characterize Solid-State Active Pharmaceutical Ingredients: Proof of Concept

Solid‐State NMR Spectroscopy

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Product

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NMR Longitudinal Rotating Frame Relaxation Time (T_1ρ) with a Weak Spin Locking Field as an Approach to Characterize Solid-State Active Pharmaceutical Ingredients: Proof of Concept