Morphological Feature of Pluronic F127 and Its Application in Burn Treatment.

The morphological features of pluronic F127 at various concentrations were investigated and 20% aqueous pluronic F127 solution was chosen for the preparation of biomembrane. The pluronic solution was mixed with appropriate concentration of excipients such as PVA, Povidon S630, PG, Nipagin, Neomycin and Panthenol. The prepared pluronic F127 was thermosensitive, a liquid phase at low temperatures (≤10 °C) but converting into gel at temperatures above 20 °C, and formed stable biomembrane at 37 °C. The neomycin impregnated pluronic membrane suppressed the bacterial growth on agar plate by the sustained release of neomycin. The histological images of skin tissue after applying pluronic gel to burn injured area on rabbit confirmed that the pluronic F127 formulation functioned as a matrix to release drug as well as a biomembrane to protect burn injury. Thus, the formulated pluronic F127 may have a potential for the application of local treatment on burn injury.

Preparation and Biophysical Characterization of Poly(amidoamine) Dendrimer-Poly(acrylic acid) Graft.

A series of PAMAM dendrimer generation 5-poly(acrylic acid) grafts were prepared to evaluate the potential use of dendritic grafts as a drug encapsulated nanocarrier. The structural features of the synthesized polymer graft were identified by FT-IR and 1H-NMR spectra and the biophysical properties were characterized by measuring its particle size and zeta potential. The prepared dendrimer G5-PAA grafts had particle size in the range of 600 to 900 nm and the size increased proportionally with the number of PAA on dendrimer surface. The electrostatic property of the dendrimer G5-PAA, carried out by HPLC reversed phase column analysis and the measurement of zeta potential, revealed that both migration time and zeta potential were dependent on the number of grafted PAA. The number of free amino groups on dendrimer G5-PAA, determined quantitatively by fluorescamine assay, was in a reverse order with the reaction mole ratio of dendrimer to PAA. In addition, dendrimer G5-PAA showed a pH-dependent solubility in aqueous solution with characteristic pH region of solubility, depending on the dendrimer generation. The observed biophysical properties indicate that PAMAM dendrimer G5-PAA is promising as a drug encapsulated nanocarrier.

Preparation and biophysical characterization of pluronic F127-dendrimer conjugate as a delivery agent of antisense oligonucleotides.

A series of pluronic F127 conjugated PAMAM dendrimer generation 5 were prepared to evaluate the potential use of dendrimer-pluronic conjugates as a delivery agent of antisense oligonucleotides. The structural features of the conjugates were identified by FT-IR and 1H-NMR spectra. The prepared dendrimer generation 5-pluronic F127 conjugates showed particle size in the range of 50 to 130 nm with reduced zeta potential. The electrophoretic property of conjugates was further confirmed by capillary zone electrophoresis (CZE), demonstrating the decrease in electrophoretic mobility of conjugates as the number of pluronic F127 on surface of dendrimer increases. The number of free amino groups on a pluronic F127 conjugated dendrimer was quantitatively determined by fluorescamine assay, measuring the fluorescence intensity of amino groups reactive to fluorescamine on dendrimer generation 5-pluronic F127 conjugates. In MTT assay, dendrimer G5-pluronic F127 conjugates were safe on gingival fibroblast cells and acute toxicity was reduced as the mole ratio of dendrimer to pluronic increased. Complex formation of dendrimer G5-pluronic F127 conjugates with oligonucleotides was dose dependent.

Chitosan-TPP nanoparticle as a release system of antisense oligonucleotide in the oral environment.

Antisense oligonucleotide loaded chitosan nanoparticles were prepared and the release of oligonucleotide from chitosan-TPP/oligonucleotide nanoparticles was investigated. Morphological property, zeta potential and particle size of the prepared chitosan/oligonucleotide nanoparticles were investigated using Field Emission-Scanning Electron Microscope (FE-SEM) and particle size analyzer. The interaction between chitosan and oligonucleotide was confirmed by using capillary zone electrophoresis (CZE), and the released oligonucleotides were determined by spectrophotometric method. Oligonucleotides formed the complexes with chitosan with a unique morphological property. The release of oligonucleotides from nanoparticles was dependent on loading methods and pH conditions. Chitosan/oligomer-TPP nanoparticles, which was prepared by adding TPP after the formation of chitosan/oligonucleotide complex, showed the lowest release percent of oligonucleotides with 41.3% at pH 7.0 among the loading methods. The percent release of oligonucleotide from oligonucleotide loaded chitosan nanoparticle at pH 10 was higher than the one in acidic condition (pH 5.0). The released oligonucleotides from chitosan/oligonucleotide nanoparticles were stable enough for 12 h under the 20% saliva solution. Our results suggest that the sustained release of oligonucleotide from chitosan nanoparticles may be suitable for the local therapeutic application in periodontal diseases.

Acetate wheat starch improving blood glucose response and bilan lipid on obesity dyslipidemia mice

Abstract Resistant starch is particularly concerned with beneficial effects in regulating blood glucose concentration and lipid metabolism, reducing the risk of diabetes and cardiovascular diseases. This study aimed to validate the effects of wheat starch acetate containing 32.1% resistant starch on postprandial blood glucose response and lipid profile on obesity, dyslipidemia Swiss mice induced by a high-fat diet. The result showed that there was a restriction on postprandial hyperglycemia and remained stable for 2 hours after meal efficiently comparing with the control group fed natural wheat starch. Simultaneously, when maintaining the dose of 5g/kg once or twice a day for 8 weeks, wheat starch acetate to be able to reduce body weight and blood glucose, triglyceride, cholesterol levels compared to the control group (p<0.05)

Effects of reducing postprandial hyperglycemia and metabolism of acetate wheat starch on healthy mice

Abstract Recently, the acetate wheat starch (AWS) has been prepared by acetylation with an acetyl content of 2.42%, containing of rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) with 25.0%; 22.9% and 34.5%, respectively. In this study, this kind of starch was continuously evaluated with the postprandial blood glucose response and determined short-chain fatty acids (SCFAs) metabolized from AWS in the gastrointestinal tract of healthy mice by HPLC. The result showed that the mice fed with AWS exhibited a very limited increase in blood glucose level and remained stable for 2 hours after meals efficiently comparing with the control group fed with natural wheat starch (NWS). Simultaneously, the content of SCFAs produced in the caecum of the mice fed with AWS was significantly higher than mice fed with NWS, especially with acetic and propionic acids by 28% and 26%, respectively. Thus, AWS has shown to limit the postprandial hyperglycemia in mice effectively through the resistance to amylase hydrolysis in the small intestine. When going into the caecum, it is fermented to form SCFAs providing a part of energy for the body's activities, avoiding rotten fermentation causing digestive disorders which are inherent restrictions of normal high cellulose and fiber food.

PAMAM dendrimer generation 5-pluronic F127 nanofilm as a matrix for local metronidazole release.

A series of dendrimer G5-pluronic F127 nanofilms (at 1:10, 1:20 and 1:30 mole ratios), loaded with various percent of metronidazole hydrochloride, were prepared by the drug deposition with/without gelatin coating. The nanostructural feature of dendrimer G5-pluronic F127 as a matrix for a sustained drug release was investigated by choosing metronidazole, an antibacterial and antiprotozoal drug as a model drug. The studies on surface morphology, polymer erosion and metronidazole release of the prepared nanofilms revealed unique surface morphology, low film erosion rate and long drug release time. The drug release and the erosion rate of nanofilm were slowed in acidic pH condition and the presence of saliva in medium. The nanofilm of G5-PF127 (1:30 mole ratio) coated with gelatin further prolonged metronidazole release showing G5-PF127 coated with 20% gelatin to be the best suited for a metronidazole release. The nanofilms were stable for up to 9 months at dried condition, while those stored at room temperature with 30% relative humidity were less stable. Our results show that PAMAM dendrimer G5-pluronic F127 nanofilm has a potential to serve as a matrix for the local drug delivery.