Synthesis, Vibrational Spectroscopic and Thermal Properties of Oxocarbon Cross-Linked Chitosan

Souza, Nelson Luís Gonçalves Dias de; Salles, Tamyres F.; Brandão, Humberto M.; Edwards, Howell G. M.; Oliveira, Luiz Fernando Cappa de

doi:10.5935/0103-5053.20150090

Cited by 12 publications

(11 citation statements)

References 2 publications

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“…The strong absorption band in this region at the wavenumber of 1370 cm −1 comes from chitosan. This is consistent with the reports of other authors [ 37 , 40 , 41 ]. The band with the maximum at 1910 cm −1 (shaded), characteristic for the DMASQ dye, appears in the spectra of doped CS films.…”

Section: Resultssupporting

confidence: 94%

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Chitosan as a Protective Matrix for the Squaraine Dye

et al. 2021

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Chitosan was used as a protective matrix for the photosensitive dye-squaraine (2,4-bis[4-(dimethylamino)phenyl]cyclobutane-1,3-diol). The physicochemical properties of the obtained systems, both in solution and in a solid-state, were investigated. However, it was found that diluted chitosan solutions with a few percent additions of dye show an intense fluorescence, which is suppressed in the solid-state. This is related to the morphology of the heterogeneous modified chitosan films. The important advantage of using a biopolymer matrix is the prevention of dye degradation under the influence of high energy ultraviolet (UV) radiation while the dye presence improves the chitosan heat resistance. It is caused by mutual interactions between macromolecules and dye. Owing to the protective action of chitosan, the dye release in liquid medium is limited. Chitosan solutions with a few percent additions of squaraine can be used in biomedical imaging thanks to the ability to emit light, while chitosan films can be protective coatings resistant to high temperatures and UV radiation.

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Section: Resultssupporting

confidence: 94%

“…Also, tertiary amines do not absorb in the range above 3200 cm −1 . These results are in line with literature data for another derivative of square acid [ 37 , 38 ].…”

Section: Resultssupporting

confidence: 93%

Chitosan as a Protective Matrix for the Squaraine Dye

et al. 2021

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“…This can be supported by the fact that depending on the reaction conditions and the molecular structure of the reacting species, the imine band can appear anywhere between 1640 cm −1 and 1550 cm −136 . Souza and co-workers (2015) also reported C=N peak at 1536 cm −1 wherein chitosan was covalently crosslinked with squarate oxocarbon ions 37 . A further search of literature referring to C=N IR peak in organic compounds revealed that imine functionality can exist at or around 1545 cm −138 .…”

Section: Resultsmentioning

confidence: 95%

Macroporous chitosan/methoxypoly(ethylene glycol) based cryosponges with unique morphology for tissue engineering applications

Kumar

Pillay

Choonara

2021

Sci Rep

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Three-dimensional porous scaffolds are widely employed in tissue engineering and regenerative medicine for their ability to carry bioactives and cells; and for their platform properties to allow for bridging-the-gap within an injured tissue. This study describes the effect of various methoxypolyethylene glycol (mPEG) derivatives (mPEG (-OCH3 functionality), mPEG-aldehyde (mPEG-CHO) and mPEG-acetic acid (mPEG-COOH)) on the morphology and physical properties of chemically crosslinked, semi-interpenetrating polymer network (IPN), chitosan (CHT)/mPEG blend cryosponges. Physicochemical and molecular characterization revealed that the –CHO and –COOH functional groups in mPEG derivatives interacted with the –NH2 functionality of the chitosan chain. The distinguishing feature of the cryosponges was their unique morphological features such as fringe thread-, pebble-, curved quartz crystal-, crystal flower-; and canyon-like structures. The morphological data was well corroborated by the image processing data and physisorption curves corresponding to Type II isotherm with open hysteresis loops. Functionalization of mPEG had no evident influence on the macro-mechanical properties of the cryosponges but increased the matrix strength as determined by the rheomechanical analyses. The cryosponges were able to deliver bioactives (dexamethasone and curcumin) over 10 days, showed varied matrix degradation profiles, and supported neuronal cells on the matrix surface. In addition, in silico simulations confirmed the compatibility and molecular stability of the CHT/mPEG blend compositions. In conclusion, the study confirmed that significant morphological variations may be induced by minimal functionalization and crosslinking of biomaterials.

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“…The intensity of the polymeric organic compounds is lower than the inorganic part, but some bands were identified for the bending vibrations of C-NH-C (277.6 cm −1 ), COC (469 cm −1 ), CO-NH (497 cm −1 ), C-CH 3 (497 cm −1 ), and CH (1249 cm −1 ). Additionally, the band at 1249 cm −1 can be ascribed to the stretching of C-C and C-O [ 40 , 41 ].…”

Section: Resultsmentioning

confidence: 99%

A Full Set of In Vitro Assays in Chitosan/Tween 80 Microspheres Loaded with Magnetite Nanoparticles

et al. 2021

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Microspheres have been proposed for different medical applications, such as the delivery of therapeutic proteins. The first step, before evaluating the functionality of a protein delivery system, is to evaluate their biological safety. In this work, we developed chitosan/Tween 80 microspheres loaded with magnetite nanoparticles and evaluated cell damage. The formation and physical–chemical properties of the microspheres were determined by FT-IR, Raman, thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDS), dynamic light scattering (DLS), and SEM. Cell damage was evaluated by a full set of in vitro assays using a non-cancerous cell line, human erythrocytes, and human lymphocytes. At the same time, to know if these microspheres can load proteins over their surface, bovine serum albumin (BSA) immobilization was measured. Results showed 7 nm magnetite nanoparticles loaded into chitosan/Tween 80 microspheres with average sizes of 1.431 µm. At concentrations from 1 to 100 µg/mL, there was no evidence of changes in mitochondrial metabolism, cell morphology, membrane rupture, cell cycle, nor sister chromatid exchange formation. For each microgram of microspheres 1.8 µg of BSA was immobilized. The result provides the fundamental understanding of the in vitro biological behavior, and safety, of developed microspheres. Additionally, this set of assays can be helpful for researchers to evaluate different nano and microparticles.

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Synthesis, Vibrational Spectroscopic and Thermal Properties of Oxocarbon Cross-Linked Chitosan

Cited by 12 publications

References 2 publications

Chitosan as a Protective Matrix for the Squaraine Dye

Chitosan as a Protective Matrix for the Squaraine Dye

Macroporous chitosan/methoxypoly(ethylene glycol) based cryosponges with unique morphology for tissue engineering applications

A Full Set of In Vitro Assays in Chitosan/Tween 80 Microspheres Loaded with Magnetite Nanoparticles

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