Table 3Drug release kinetics of poly(AA-co-VSA) hydrogels in solutions of different pHs.The equation selleck Ponatinib of Mt/M�� = ktn was used to study the mechanism of drug release [28], where Mt/M�� is the drug release fraction at time t, k is the kinetic constant, and n is the release exponent describing the release mechanism. When n = 0.5, Fickian diffusion, also known as Case I diffusion, occurs; if n = 1, drug release follows zero-order or Case II transport; 1 > n > 0.5, non-Fickian or anomalous drug transport when the rate of diffusion and polymer relaxation simultaneously occur. It can be seen that the values of release exponent (n) were between 0.5 and 1; therefore, drug release from the hydrogel followed non-Fickian release mechanism (Table 3). 4.

ConclusionIn the present work pH-sensitive AA/VSA hydrogels have been successfully prepared by free radical polymerization using EGDMA as cross-linking agent and benzyl peroxide as reaction initiator. Hydrogels showed a pH dependent swelling behaviour which was found to be maximum at pH 7.5 of the medium. It was also observed that swelling of hydrogel increases when increasing the concentration of PVSA and decreases when increasing the concentrations of AA and EGDMA in the gels. Structural parameters confirmed different architectural aspects of hydrogels necessary for proper functioning. These gels were successfully loaded with model drug (isosorbide mononitrate) and FTIR spectra confirmed absence of drug polymer interaction. Thermal analysis showed thermal stability of polymeric network and molecular dispersion of drug in the hydrogels.

It was observed that drug release decreases when increasing the amount of AA, but it increases when increasing the concentration of PVSA and pH of the medium. Release kinetic analysis revealed a non-Fickian diffusion mechanism for the release of the isosorbide mononitrate. These results suggest that poly(acrylic-co-vinylsulfonic) acid hydrogels can be used as potential pH-sensitive drug delivery systems.Conflict of InterestsThe authors hereby declare that there is no conflict of interests.AcknowledgmentThe authors would like to thank Bahauddin Zakariya University, Multan, Pakistan, for providing funding to conduct this research.
Chrysanthemum (Chrysanthemum morifolium) is an important ornamental species, particularly in China.

With the increasingly urbanized Chinese population experiencing a marked rise in its standard of living, chrysanthemum production is rising. As is also the case GSK-3 for many crops [1�C5], long-term monocropping of chrysanthemum depresses crop productivity, in terms of both quantity and quality. One of the major causes for this decline in productivity is thought to be the changed nature of the soil fungal population and specifically the buildup of soil-borne pathogens. Soil fungi are important in the context of nutrient cycling and transport and carbon recycling [6�C8].