Colloidal physical gels of pure chitosan were obtained via an ammonia-induced gelation in a reverse phase emulsion. The water weight fraction and the chitosan concentration in the water phase were optimized so as to yield nanogels with controlled particle size and size distribution. The spherical morphology of the nanogels was established by transmission electron microscopy with negative staining. Wide-angle X-ray scattering experiments showed that these gels were partially crystalline. The electrophoretic mobilities of the particles remained positive up to pH 7, above which the particles aggregated due to the charge neutralization. From the investigation on the colloidal stability of these nanogels in various conditions (pH, salt concentration, temperature), an electrosteric stabilization process of the particles was pointed out, related to the conformation of mobile chitosan chains at the gel-liquid interface. Therefore, the structure of the nanogels was deduced as being core-shell type, a gelified core of neutralized chitosan chains surrounded by partially protonated chains.
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http://dx.doi.org/10.1021/la9002753 | DOI Listing |
Mater Today Bio
February 2025
State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan, 430079, China.
Inspired by the initial mineralization process with bone matrix vesicles (MVs), this study innovatively developed a delivery system to mediate mineralization during bone regeneration. The system comprises nanofibrous chitosan microspheres (NCM) and poly (allylamine hydrochloride)-stabilized amorphous calcium phosphate (PAH-ACP), which is thereafter referred to as NCMP. NCM is synthesized through the thermal induction of chitosan molecular chains, serving as the carrier, while PAH-ACP functions as the mineralization precursor.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Research Institute of Interdisciplinary Science, School of Materials Science and Engineering, Dongguan University of Technology, Dongguan 523808, China; Guangdong Provincial Key Laboratory of Extreme Conditions, Dongguan 523803, China. Electronic address:
The application of chitosan in packaging has always been limited due to its brittle and hygroscopic nature. In this study, hydrophobic short-chain fatty acids (SCFAs) were utilized to modify chitosan to overcome this issue. For the first time, hydrophobic SCFAs, typically hexanoic acid and its homologs, were found to be able to dissolve chitosan in water as well as its hydrophilic analog.
View Article and Find Full Text PDFMolecules
January 2025
Grupo Biomateriales Dentales, Escuela de Odontología, Universidad del Valle, Calle 4B # 36-00, Cali 760001, Colombia.
Scaffolds for regenerative therapy can be made from natural or synthetic polymers, each offering distinct benefits. Natural biopolymers like chitosan (CS) are biocompatible and biodegradable, supporting cell interactions, but lack mechanical strength. Synthetic polymers like polyvinyl alcohol (PVA) provide superior mechanical strength and cost efficiency but are not biodegradable or supportive of cell adhesion.
View Article and Find Full Text PDFMolecules
January 2025
Department of Chemical Engineering, Universitat Rovira i Virgili, Av. Països Catalans 26, Campus Sescelades, 43007 Tarragona, Spain.
pH sensitivity of chitosan allows for precise phase transitions in acidic environments, controlling swelling and shrinking, making chitosan suitable for drug delivery systems. pH transitions are modulated by the presence of cross-linkers by the functionalization of the chitosan chain. This review relays a summary of chitosan functionalization and tailoring to optimize drug release.
View Article and Find Full Text PDFMikrochim Acta
January 2025
Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, National & Local Joint Engineering Research Center for Mineral Salt Deep Utilization, Huaiyin Institute of Technology, Huaian, 223003, P. R. China.
A highly sensitive and selective electrochemical biosensor was developed for the detection of kanamycin using a core-hollow-shell structured peroxidase-mimic nanozyme, CHS-Fe₃O₄@@ZIF-8. The synthesized CHS-FeO@@ZIF-8 was characterized with scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. It was found that the CHS-FeO@@ZIF-8 exhibits excellent peroxidase-like activity due to its ultra-thin hollow layer.
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