Preparation and Characterization of Zwitterionic Poly(β-cyclodextrin-co -guanidinocitrate) Hydrogels for Ciprofloxacin Controlled Release

Abstract

A facile, safe, and environmentally friendly approach to the preparation of poly(β‐cyclodextrin‐co‐guanidinocitrate) (ZWβCDP) via polymerization of β‐cyclodextrin (β‐CD) in the presence of guanidinocitrate as a novel cross‐linker is reported. Novel zwitterionic guanidinocitrate cross‐linker is synthesized by in situ reaction of melted guanidine and citric acid during polymerization. The structure of achieved hydrogels is characterized by attenuated total reflection‐Fourier‐transform infrared (ATR‐FTIR), X‐ray photoelectron spectroscopy, thermogravimetric analysis, differential thermogravimetric, differential scanning calorimetry (DSC), differential of DSC, and X‐ray diffraction analyses and also by Kjeldahl and colorimetric methods for elemental analyses. The swelling ratio of the anionic β‐CD polymer (ANβCDP) and ZWβCDPs is determined in water and simulated physiological media. Subsequently, the hydrogels/ciprofloxacin (CFX, as a model antibiotic drug) complexes are prepared to improve the thermal stability of CFX and define potential pharmaceutical applications of hydrogels. Solid‐state characterization of hydrogels/CFX complexes is investigated by ATR‐FTIR and DSC. The in vitro release behavior of CFX from hydrogels is investigated at simulated physiological media, which exhibit initial burst and then slow drug release. The CFX release from ZWβCDP is slower than ANβCDP.

Preparation of cellulosic drug‐loaded hydrogel beads through electrostatic and host–guest interactions

“…When the hydrogel reaches the swelling equilibrium, a gradual degradation of the hydrogel inevitably occurs, which is the reason for the quick release in this stage. In addition, for IBU molecules that are associated with CD + by the inclusion interactions or with ionic branches using electrostatic interaction, the release occurs through a slower dissociation and diffusion . This release process fits the first‐order kinetic model, which is the typical concentration diffusion process.…”

“…Because the encapsulating stoichiometry ratio of DETA‐β‐CD and IBU is 1:1, 30.5% of the IBU was not encapsulated into the inner cavity of DETA‐β‐CD, which was higher than IBU not encapsulated into the inner cavity of CD + . DETA‐β‐CD adsorbed on the surface of the hydrogel network and lack of electrostatic interactions gave rise to the initial release . In the simulated release kinetic model, stage I fits the Korsmeyer and Peppas model, because the value of the correction coefficient is high (0.979) and is greater than those of the zero‐order, first‐order, and Higuchi models.…”

“…Because the release process is also a Fickian diffusion process, the concentration diffusion of IBU encapsulated by the CD + is the main reason. Furthermore, a small amount of IBU adsorbed on the surface of the hydrogel network and physically encapsulated into the networks (10.5%) can be released quickly from the hydrogel into the simulated intestinal fluid . Besides, the concentration gradient also affects the complexation–decomplexation phenomena within the CD hydrogels.…”

Cyclodextrin polymer coatings resist protein fouling, mammalian cell adhesion, and bacterial attachment

“…The polymers produced by HDI-crosslinking were more robust, therefore we considered HDI a more useful crosslinker for preparation of pCD coating materials here. There are many other possible crosslinkers that could be considered 90,[111][112][113][114] . Similarly, different CD subunits were not evaluated in this study.…”

Au Nanoparticles Immobilized in Fe3O4/SBA‐16 Functionalized Melamine–α–Chloroacetic Acid as a Recoverable Nanocatalyst for Reduction of Dye Pollutants in Water

“…SBA‐16 is more porous than SBA‐15, and the organic functional groups of the catalyst easily fall within its pores, giving it an excellent catalytic performance. Following our previous works in preparation of nanocatalysts and nanocomposites to degrade and eliminate organic dyes, the current study focused on the synthesis of Fe 3 O 4 /SBA‐16‐MH−Au magnetic mesoporous (MMS) nanocatalysts by grafting of melamine bearing α–chloroacetic acid groups on SBA‐16 and subsequent deposition of Au nanoparticles. The nanocatalyst was shown an excellent magnetic property that can be easily separated from the reaction mixture by using of an external magnet.…”