Release behavior of a polyanion‐crosslinked chitosan‐poly(N‐isopropylacrylamide) gel thermoresponsive material

Abstract

A novel type of temperature‐responsive hydrogel with sensitive release performance of an encapsulated compound was obtained. The temperature‐responsive hydrogel with a sensitive state change between 32 °C and 29 °C was prepared by physically crosslinking chitosan with a polyanion of tripolyphosphate and linear poly(N‐isopropylacrylamide) (PNIPAAm). Cyanocobalamin was used as a model drug and was encapsulated in the prepared hydrogel. The swelling ratio and release behavior of cyanocobalamin were evaluated. Hydrogels containing 3.0% chitosan and 3.0% PNIPAAm had the best swelling ratio and the maximum amount of released encapsulated cyanocobalamin. The amount of released cyanocobalamin was quantified at 25 °C and 40 °C to evaluate the release behavior. The encapsulated cyanocobalamin remained within the hydrogels at 25 °C and was rapidly released at 40 °C. After 1 min at 40 °C, the released amount was approximately 50% of the encapsulated cyanocobalamin. The temperature‐responsive hydrogels obtained have good performance for use in drug delivery systems. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46732.

Thermosensitive Hydrogel for Encapsulation and Controlled Release of Biocontrol Agents to Prevent Peanut Aflatoxin Contamination

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Preparation of Long-Term Antibacterial SiO2-Cinnamaldehyde Microcapsule via Sol-Gel Approach as a Functional Additive for PBAT Film

“…The microcapsule structure effectively prolongs the release and diffusion of CA, and with the accumulation of CA release, the release rate gradually slows down. Ueoka and Mohammadi et al [32,43] have also noticed the effect of temperature and stated that high temperature can control the release of antibacterial agents and low temperature can delay its effect. Figure 6B shows the sustained release profile of SiO2-CA microcapsules at different humidity levels (90%, 70%, and 50% RH).…”

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“…57 Another study reported a similar crosslinking of chitosan with a polyanion of tripolyphosphate and poly(N-isopropylacrylamide) (PNIPAAm) possessing thermoresponsive behavior. 58 It is possible to tailor such crosslinking as per the application since it is triggered by a pH change that causes protonation and deprotonation of the ionic functional groups. In a few cases, it may also form in situ hydrogels due to physiological pH, for example, chitosan undergoes ionic interaction with negatively charged βglycerophosphate to form thermosensitive in situ hydrogels for the delivery of 188 Re-Tin colloid, 59 doxorubicin, 59 and ibuprofen.…”

“…Thermoresponsive xyloglucan/cellulose nanocrystal hydrogels present an LCST close to the body temperature since they progressively convert from sol to gel state at 35 °C . There are numerous reports on the thermoresponsive behavior of chitosan-based hydrogels showing sharp phase transition above the LCST or around body temperature that depict several applications. − ,,,,, Moreover, rheological measurements such as the temperature sweep test also determine the thermos-reversible nature of the hydrogels utilized to determine the thermoresponsive behavior of gelatin/gellan and chitosan/β-glycerophosphate hydrogel. Here, G ′ is always greater than G ′′, which increases gradually and becomes resistant to temperature change.…”

“…Moreover, Singha et al have recently reviewed intelligent drug delivery through injectable chitosan hydrogels . As mentioned earlier, due to the incidence of diverse functional groups and polymerization with different active compounds, chitosan exhibit pH, temperature, light, magnetic, electric, and redox-responsiveness, which has been employed for the delivery of disulfiram, adriamycin, rifampicin, doxorubicin, ,, protein, cyanocobalamine, dexamethasone, moxifloxacin hydrochloride, and curcumin, etc. Interestingly, polysaccharides are known to exhibit health benefits so Eyigor et al utilized β-glucan for thermoresponsive delivery of mesalazine or 5-aminosalicylic acid (5-ASA) which is an anti-inflammatory drug .…”