Destruction of chitosan capsules based on host–guest interaction and controllable release of encapsulated dyes

Abstract

This article describes a new and simple method to control the release of payloads encapsulated in chitosan capsules. The capsules with the liquid core and rigid shell are performed by drop‐wisely adding chitosan solution into anionic surfactant solution. The capsules can be destroyed by β‐CD because β‐CD binds and sequesters surfactant from the shell through the host‐guest interaction. The destruction process is studied by optical microscopy and scanning electron microscopy. The capsules can swell in acid solution and shrink in alkaline solution. It is found that the destruction speed increases with increasing acidity or alkalinity of β‐CD solution. Rhodamine B encapsulated in the liquid‐core of chitosan capsules can be released from the capsules in β‐CD solution. The release rate can be adjusted by the pH value of β‐CD solution. The release speed of the capsule increases with the increase of acidity or alkalinity in β‐CD solution. The above concept can provide more versatility for controlled release of a variety of payloads such as drugs, cosmetics, and so on. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45229.

Fabrication, encapsulation and controlled release of multilayer capsule based on thermosensitivity and host‐guest interaction

“…Our previous study found that the shell of CS‐SDBS capsules could be destructed once α‐CD contacted 25 . To take advantage of this feature, α‐CD was encapsulated in the gelatin beads to generate α‐CD@gelatin/CS‐SDBS multilayer capsules.…”

“…Our previous study found that the shell of CS-SDBS capsules could be destructed once α-CD contacted. 25 To take advantage of this feature, α-CD was encapsulated in the gelatin beads to generate α-CD@gelatin/CS-SDBS multilayer capsules. The FTIR spectra of gelatin beads, gelatin/ CS-SDBS capsules, and α-CD@gelatin/CS-SDBS capsules were shown in Figure 3a.…”

“…18,19 In addition, controlled release can also be achieved by using the interaction between substances. [20][21][22][23][24] In our previous work, 25 it was found that cyclodextrin (CD) could change the permeability of the outer membrane of chitosan (CS) and sodium dodecylbenzene sulfonate (SDBS) capsules, which promotes the release of dyes in the liquid core of the CS/SDBS capsules. It is attributed to the decomposition of capsule membrane caused by the hostguest interaction between CD and SDBS.…”

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“…One of the most extended approach to obtain capsules is the ionotropic gelation method, in which cations form insoluble associates with carbohydrate chains resulting in the so-called "egg-box" complexes [25,26]. Alginate, majorly associated to calcium cations, has been largely used to encapsulate products [27][28][29], a similar case is pectin [30,31], chitosan [32,33], and mix of these [34,35].…”

Aggregation of Cyclodextrins: Fundamental Issues and Applications

“…Table 1 summarizes some relevant physical-chemical parameters of the three most common natural cyclodextrins (α-, β-, and γ-CDs). CDs are able to solubilize, protect, or transport a large variety of compounds, e.g., inorganic nonassociated salts [5,6], surfactants [7][8][9], and nonpolar drugs, by forming inclusion and noninclusion complexes. These CD-guest interactions are facilitated by the unique structure of CD, which combines a hydrophilic outer surface with an internal lipophilic cavity.…”