pH- and thermo-sensitive semi-IPN hydrogels composed of chitosan, N-isopropylacrylamide, and poly(ethylene glycol)-co-poly(ε-caprolactone) macromer for drug delivery

Zhao, Shenghui; Li, Liyan; Cao, Meng-Jie; Xu, Weilin

doi:10.1007/s00289-010-0390-y

Cited by 26 publications

(7 citation statements)

References 28 publications

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“…Swelling occurs due to the hydrophilic groups, and more positively charged amino groups along the biopolymer chain are responsible for an expanding polymer network. 70 , 71 In addition, the swelling behavior of the capsules mainly results from the electrostatic discord between the negatively charged carboxyl groups on alginate and gelatin. Paula et al 56 prepared chitosan/cashew gum (CH/CG) beads loaded with insecticide dichlorvos.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of released malathion and spinosad from chitosan/alginate/gelatin capsules against <em>Culex pipiens</em> larvae

Badawy¹,

Taktak²,

Awad³

et al. 2016

RRTM

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Efficacy of spinosad and malathion loaded in eco-friendly biodegradable formulations was evaluated for controlling Culex pipiens larvae. Malathion (organophosphorus larvicide) and spinosad (naturally derived insecticide) were loaded on chitosan/alginate/gelatin capsules. Capsules were characterized by size measurement, scanning electron microscopy, Fourier transform infrared spectroscopy, and water uptake. In vitro release kinetics of the larvicides was studied in the running and stagnant water. Biochemical studies on the larvae treated with technical and formulated insecticides were also demonstrated. The results indicated that the released spinosad was active for a long time up to 48 and 211 days in the running and stagnant water, respectively. However, the capsules loaded with malathion showed larvicidal activity for 20 and 27 days in the running and stagnant water, respectively. Technical and formulated malathion and spinosad had an inhibition effect on acetylcholinesterase, carboxylesterase, and glutathione S-transferase. The results proved that the prepared capsules consisting of biodegradable polymers containing larvicides could be effective as controlled-release formulation against C. pipiens larvae for a long period.

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Section: Resultsmentioning

confidence: 99%

Evaluation of released malathion and spinosad from chitosan/alginate/gelatin capsules against <em>Culex pipiens</em> larvae

Badawy¹,

Taktak²,

Awad³

et al. 2016

RRTM

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“…Moreover, at higher temperature (37 °C), drug release in DW was also found to be decreased accordingly for both samples. These results showed that with temperature increase, release of drug from the in situ gel matrix decreases, owing to the aggregated state at higher temperature [43]. Figure 11D indicates the cumulative % 5-FU release from IPLVCS-2 hydrogels in DW at variable temperature.…”

Section: Temperature and Ph Effect On Drug Releasementioning

confidence: 90%

Fabrication and evaluation of smart pH/thermo dual-responsive injectable intratumoral in situ depot hydrogels for controlled 5-FU delivery

Khan,

2023

Beni-Suef Univ J Basic Appl Sci

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Background 5-FU has multiple applications in various cancers but has limitations owing to its shorter half-life and rapid metabolism. In this study, injectable intratumoral gels were developed to enhance 5-FU concentrations in tumor vicinity. Sterile tunable poly (N-isopropylacrylamide)-based pH/thermo dual-sensitive self-assembled and in situ crosslinkable injectable depot gels with low viscous grade of chitosan (LVCS) were developed via cold and free radical polymerization method for localized and sustained delivery. Results Rheological analysis confirmed the gelation temperature, sol–gel transitions and viscoelastic behavior of in situ gels. Swelling–deswelling–reswelling cycles established the effect of temperature on structural changes. Swelling tests and in vitro drug release conducted in various dissolution media at variable temperatures confirmed pH/thermal dual response of formulations. Methyl thiazolyl tetrazolium assay confirmed that the hydrogels have good cytocompatibility with above 85% cells viability in Vero cells. In vitro cytotoxicity assay against MCF-7 cells displayed that 5-fluorouracil has good anticancer activity in loaded gel form as compared to free 5-FU. The cytotoxic studies showed that IPLVCS-2 and IPLVCS-6 have the highest inhibition (IC50 = 47 ± 1 µg/ml, 34 ± 17 µg/ml) as compared to free 5-FU (IC50 = 52 ± 3 µg/ml). Conclusion Current findings conclude that taking the advantage of physiologic environment acidic pH and high temperature of cancer cells, poly(NIPAAm)-g-LVCS formulations can effectively be used as intratumoral controlled depot of 5-FU. Graphical Abstract

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“…For instance, the much faster response rates of IPN4 are useful in cases where fast response rates are required such as in artificial organs and in on-off switches (Osada et al 1992). As a matter of fact, many studies reported recently focused on the improvement of the response rate of thermosensitive hydrogels (Temtem et al 2012, Chen et al 2012, Zhao et al 2011.…”

Section: Swelling Ratio Of Chitosan/ Gelatin/nipaam Hydrogelsmentioning

confidence: 99%

Preparation and characterization of a thermal responsive of poly(N-isopropylacrylamide)/chitosan/gelatin hydrogels

Baghaei¹,

Khorasani

2014

Biomaterials and Biomedical Engineering

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Synthesis of interpenetrating polymer network (IPN) of chitosan-gelatin (Cs-Ge) (as a primary network) and N-isopropylacrylamide (NIPAAm) monomer (as the secondary network) was carried out with different ratio. Its structure was characterized by FT-IR, which indicated that the IPN was formed. The memberanes were studied by swelling, weight loss with time. The interior morphology of the IPN hydrogels was revealed by scanning electron microscopy (SEM); the IPN hydrogels showed a interpenetrated network of NIPAAm/chitosan has layers with more minute stoma and canals compared to interpenetrated network of NIPAAm/gelatin. Lower critical solution temperature (LCST), equilibrium swelling ratio (ESR) and deswelling kinetics were measured. The DSC results noticed that LCST of IPN hydrogels with different ratio of Cs/Ge/PNIPAAm are around 33±2°C. The ESR obtained results showed that with a ratio of Cs/Ge/NIPAAm: 1/1/6, the swelling ratio increased drastically from room temperature to 36°C but with a ratio of Cs/Ge/PNIPAAm: 1/3/6, decrease significantly at the same condition. Therefore the hydrogels have been changed from a hydrophilic structure to a hydrophobic structure. Furthermore with an increase in temperature from room to the LCST, the ESR of IPN with higher concentration of (PNIPAAm) and (Ge) decreases but de-swelling kinetics of them are faster. Due to the suitable and different kinetics of de-swelling and the equilibrium swelling ratio (ESR) in various proportions, and because of the morphology inside the mass which confirms other tests, these hydrogels are very appropriate as a smart thermosensitive hydrogels with rapid response.

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pH- and thermo-sensitive semi-IPN hydrogels composed of chitosan, N-isopropylacrylamide, and poly(ethylene glycol)-co-poly(ε-caprolactone) macromer for drug delivery

Cited by 26 publications

References 28 publications

Evaluation of released malathion and spinosad from chitosan/alginate/gelatin capsules against <em>Culex pipiens</em> larvae

Evaluation of released malathion and spinosad from chitosan/alginate/gelatin capsules against <em>Culex pipiens</em> larvae

Fabrication and evaluation of smart pH/thermo dual-responsive injectable intratumoral in situ depot hydrogels for controlled 5-FU delivery

Preparation and characterization of a thermal responsive of poly(N-isopropylacrylamide)/chitosan/gelatin hydrogels

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