Objective: The aim of this study was to investigate the nasal safety of gel formulations of thiolated polymers (thiomers) by assessing their effect on ciliary beat frequency (CBF) in human nasal epithelial cells.
Methods: Poly(acrylic acid) 450 kDa-cysteine (PAA-cys) and alginate-cysteine (alg-cys) were synthesized by covalent attachment of L-cysteine to the polymeric backbone. The cationic polymer chitosan-thiobutylamidine (chito-TBA) was synthesized by attaching iminothiolane to chitosan. CBF using was measured by a photometric system. CBF was measured before incubating the cells with test gels, during incubation and after washing out the polymeric test gels to evaluate reversibility of cilio-inhibition. The influence of viscosity on CBF was determined by using hydroxyethylcellulose (HEC)-gels of various concentrations.
Results: Ciliary beating was observed to be affected by viscosity, but cilia were still beating in the presence of a HEC-gel displaying an apparent viscosity of 25 Pa.s. In case of thiolated polymers and their unmodified control, a concentration-dependent decrease in CBF could be observed. PAA-cys, alg-cys, chito-TBA and their corresponding unmodified controls exhibited a moderate cilio-inhibitory effect, followed by a partial recovery of CBF when used at a concentration of 1%. Alg-cys 2% and chito-TBA 2% (m/v) gels exhibited severe cilio-inhibition, which was partially reversible. L-cysteine and reduced glutathione led to mild cilio-inhibition at concentrations of 3% (m/v).
Conclusions: Taking into account that dilution after application and cilio-modifying effects is usually more pronounced under in vitro conditions, thiomers can be considered as suitable excipients for nasal drug delivery systems.
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http://dx.doi.org/10.3109/03639045.2011.584537 | DOI Listing |
Nanoscale
January 2025
State Key Lab of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.
Solving the assembled structure of Au(I)-thiolate linear coordination polymers has been a challenging task as they generally lack good crystallinity. This has prevented the elucidation of their assembly processes at the molecular level. In this paper, selected area electron diffraction (SAED) patterns of two-dimensional (2D) Au(I)-S(CH)COOH (Au(I)-MPA) lamellae are obtained by applying cryogenic transmission electron microscopy.
View Article and Find Full Text PDFBiomacromolecules
January 2025
Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
ChemSusChem
January 2025
Dalian University of Technology, State Key Laboratory of Fine Chemicals, West Campus E-223, 2 Linggong Rd.,, Dalian, CHINA.
Developing high-activity and long-term stable electrocatalysts for electrochemical CO2 reduction reaction (eCO2RR) to valuable products is still a challenge. An in-depth understanding of reaction mechanisms and the structure-function relationship is required for the development of an advanced catalytic eCO2RR system. Herein, a coordination polymer of indium(III) and benzenehexathiol (BHT) was developed as an electrocatalyst (In-BHT) for eCO2RR to HCOO-, which displayed an outstanding catalytic performance over the entire pH range.
View Article and Find Full Text PDFBiofabrication
January 2025
Polymer Chemistry and Biomaterials (PBM) Group, Centre of Macromolecular Chemistry (CMaC), Department of Organic and Macromolecular Chemistry, Faculty of Sciences, Ghent University, Krijgslaan 281, Building S4, 9000 Ghent, Belgium.
Volumetric bioprinting has revolutionized the field of biofabrication by enabling the creation of cubic centimeter-scale living constructs at faster printing times (in the order of seconds). However, a key challenge remains: developing a wider variety of available osteogenic bioinks that allow osteogenic maturation of the encapsulated cells within the construct. Herein, the bioink exploiting a step-growth mechanism (norbornene-norbornene functionalized gelatin in combination with thiolated gelatin-GelNBNBSH) outperformed the bioink exploiting a chain-growth mechanism (gelatin methacryloyl-GelMA), as the necessary photo-initiator concentration was three times lower combined with a more than 50% reduction in required light exposure dose resulting in an improved positive and negative resolution.
View Article and Find Full Text PDFCarbohydr Polym
March 2025
Department of Pharmaceutics and Pharmaceutical Nanotechnology, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Protein Technology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address:
Recurrent aphthous stomatitis (RAS) is a common condition that manifests as ulcerative lesions in the oral mucosa. In this study, bilayer, mucoadhesive nanofibers loaded with pomegranate flower extract (PFE) were prepared using thiolated gelatin (TGel) and thiolated chitosan (TCS) as the active layer and drug-free polycaprolactone (PCL) as the backing layer. Gelatin (Gel) and chitosan (CS) were successfully thiolated (proven by Ellman's assay, solubility, H NMR, FTIR, Raman spectroscopy, and XRD) and electrospun into active nanofibrous layers with a diameter of 356.
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