Characterizing the effects of different chemicals on stem bending of cut snapdragon flower.

BACKGROUND: This study investigated the effects of ethylene release compounds (ethephon), ethylene-action inhibitors (silver thiosulfate: STS), and nitric oxide donor (sodium nitroprusside: SNP) on stem bending of snapdragon flowers. Moreover, the effects of plant growth supplements [6-benzyladenine (BA), gibberellic acid 3 (GA3), and calcium chloride (CaCl2)] on the stem bending were also extensively investigated. RESULTS: Ethephon completely prevented stem bending until 9 days after treatment (9 DAT). STS exhibited the highest bending rate, while SNP did not significantly affect the bending compared to the controls. The bending results were associated with the results of stem curvature, relative shoot elongation, ethylene production, and lignin content, that are involved in the stem bending mechanism. This was proven by the expression analysis of genes involved in ethylene and lignin biosynthetic pathways. The addition of plant growth supplements slightly or significantly delayed stem bending in the treatments (control, SNP, and STS) and significantly reduced petal senescence in ethephon at 9 DAT. CONCLUSION: These results show the preventive role of ethephon in the stem bending of cut snapdragon. Moreover, the combination of ethephon with supplements also provided information that could guide the development of strategies to delay stem bending in other cut flowers that undergo serious bending during a short vase life.

Ethylene Acts as a Negative Regulator of the Stem-Bending Mechanism of Different Cut Snapdragon Cultivars.

This study investigated whether ethylene is involved in the stem-bending mechanism of three different snapdragon cultivars 'Asrit Red', 'Asrit Yellow', and 'Merryred Pink', by treating their cut stems with an ethylene-releasing compound (ethephon), an ethylene-action inhibitor [silver thiosulfate (STS)], and distilled water (as the control). Ethephon completely prevented stem bending in all cultivars, whereas STS exhibited a higher bending rate compared with the control. The bending rates were influenced by several factors, such as the degree of stem curvature, relative shoot elongation, ethylene production, and lignin content, indicating their involvement in the stem-bending mechanism of the cultivars. The analysis of the expression of genes involved in the ethylene and lignin biosynthetic pathways also supported the importance of lignin and ethylene in the stem-bending mechanism. Taken together, as ethephon completely prevented stem bending of the three snapdragon cultivars, this study suggested that ethylene acts as a negative regulator of the stem-bending mechanism of snapdragon cultivars, and the information will be valuable for the prevention of stem bending in other commercially important ornamental flowers.

Modification of release and penetration behavior of water-soluble active ingredient from ball-milled glutinous starch matrix via carboxymethylcellulose blending.

This present work describes the possible advantages of carboxymethylcellulose (CMC) blending with ball-milled glutinous starch (BMGS) on the modification of release and penetration of model water-soluble active ingredient, lidocaine hydrochloride, from the blended matrix. The 20-67% CMC mass containing CMC-BMGS matrices were fabricated by casting the aqueous dispersion of CMC-BMGS onto the tray and oven-dried. BMGS and CMC were compatible as revealed by SEM and ATR-FTIR. Irrespective of the CMC mass, all CMC-BMGS matrices showed comparable matrix mass, thickness, moisture content, moisture absorption as well as mechanical and mucoadhesive properties. The surface pH of CMC-BMGS tended to increase with the CMC mass. Depends on CMC mass, matrix properties, release, and penetration rates were modulated significantly. CMC had shown a substantial role in the swelling and erosion behaviors of BMGS films, and thus modulated the release and penetration significantly. The release and penetration mechanisms of active ingredient from the CMC-BMGS matrices were Fickian diffusion-controlled, with rates of release and penetration ranging from 2.05 ± 0.21 to 7.55 ± 1.08%/min½, and from 3.48 ± 0.28 to 8.04 ± 0.64 µg/cm2/min½, respectively. The capability of CMC-BMGS matrices as mucoadhesive delivery systems to provide sustained delivery of water-soluble active ingredients was disclosed.

Modified glutinous rice starch-chitosan composite films for buccal delivery of hydrophilic drug.

The fabrication and characterization of ball-milling modified glutinous rice starch (MGRS):chitosan (CS) composite films were demonstrated. Effect of CS ratios (2:1, 1:1, 1:2 MGRS:CS) on the film properties was investigated. Lidocaine hydrochloride was used as a model hydrophilic drug. ATR-FTIR confirmed hydrogen bond formation between MGRS and CS. XRD indicated an amorphous state of all fabricated films. The uniform and comparable thickness, weight, and drug contents of all fabricated films were obtained. The presence of CS did not affect the mucoadhesiveness of MGRS films. The increase in tensile strength and decreases in elongation and folding endurance were observed with 1:2 MGRS:CS films. The film swelling and drug release decreased with the CS ratio. Drug permeation across porcine mucosa indicated the enhancement effect of CS, whereby the permeation flux of 1:2 MGRS:CS composite increased by 3 folds. In conclusion, the MGRS:CS composite could be useful for buccal delivery of hydrophilic drug.

Thai glutinous rice starch modified by ball milling and its application as a mucoadhesive polymer.

This study aimed to investigate physicochemical properties and potential application as a mucoadhesive polymer of Thai glutinous rice starch modified by planetary ball milling. XRD and ATR-FTIR results indicated a reduction in crystallinity of starch after ball milling. Different ball milling times, ranging from 5 to 45 min, resulted in modified glutinous rice starch (MGRS) with different levels of crystallinity loss, and therefore varying degrees of cold water solubility, swelling capacity, and gelatinized dispersion viscosity. Investigation of mucoadhesive properties using Texture Analyzer with porcine mucosa demonstrated that MGRS tablets exhibited greater mucoadhesive abilities compared to hydroxypropyl methylcellulose tablets, but weaker than those of sodium carboxymethylcellulose tablets. Tablets made of 15-min-milled MGRS had comparable tableting, swelling and mucoadhesiveness, but lower erosion compared to 45-min-milled MGRS. Conclusively, ball milling treatment could successfully induce the mucoadhesive properties of Thai glutinous rice starch and expand its application as mucoadhesive polymer.