Dextrin Research Articles

Design of easily swallowable xerogel pill with enough physical strength through hardening-process under heating and humidification

The xerogel pill has been developed as a novel dosage form with dose-adjusting and swallow-assisting functions by using drop freeze-drying (DFD) technique. It was double-structured small sphere composed of an inner drug core and an outer dried-gel layer, however, had problem of insufficient physical strength. In this study, it was attempted to use dextrin (DEX), one of oligosaccharides, to strengthen the xerogel pill. DEX was co-dissolved in the dropping fluid in the DFD process and co-loaded in the conventional pill, which was mainly composed of mannitol (MNT) as a filler, to prepare the rigid body. DEX-loaded pill could be successfully prepared with high recovery (>90 %) by optimizing the ratio of DEX and MNT. Further, the representative pills with and without DEX (P-DEX and P-MNT, respectively) were hardening-processed under humidification. The physical strength of P-DEX pill was significantly increased when humidified under severe condition, resulting in enough hardness (>5N) and friability (<1.0 %). Processed P-DEX was found to have dense structure covered with a thick outer shell, which would be formed by interparticle bridge of DEX. It was also found that processed P-DEX pill suppressed initial drug dissolution significantly and exhibited sustained dissolution behavior, suggesting the potential function of bitter taste masking. Processed P-DEX pill had excellent sliding behavior with low friction forces as a result of lubricant effect of xanthan gum (XG) surrounding the pills. Furthermore, the sliding test also suggested that processed P-DEX pill had hard candy-like texture, in contrast unprocessed P-DEX pill had orally disintegrating (OD) tablet-like texture. Various xerogel pills with such different swallowing texture would have a potential to accommodate the children’s preferences when taking medication.

Engineering 5-flourouracil and leucovorin-loaded vesicular systems for possible colon specific delivery: In vitro evaluation and real time cell assay against HCT-116 colon cell lines

5-flourouracil (5-FU) is typically modulated with leucovorin (LEU) in clinical practice to improve clinical efficacy and patient survival rates. However, this combination has undesirable side effects and makes 5-FU more toxic. Hence, integrating a vesicular system (proniosomes) with another delivery vehicle may improve drug targeting, while resolving the aforementioned drawbacks. This study aimed to engineer 5-FU/LEU proniosomes for possible delivery to the colon. The modified slurry approach was used to create drug-loaded proniosomes (150 mg/9 g of carrier) using both water-soluble (dextrin (DEX) and lactose (LAC)) and insoluble (Neusilin FH2 (NEU)) carriers. The powdered formulations were filled into Eudragit S100 (10 %)-coated capsules or Eudragit FS 30D capsules for enteric- or colon-specific delivery. In vitro evaluations (flow properties, powder X-ray diffractometry (XRD) analysis, particle size analysis, entrapment efficiency, drug release, scanning electron microscopy (SEM), polydispersity index, Fourier transform infrared spectroscopy (FTIR), and stability studies) were performed on the formulations. An in vitro cytotoxicity test [real-time cell assay (RTCA)] against HCT-116 colon cancer cell lines was performed using the optimized formulation. In vitro evaluations showed that the nanoparticles had good physicochemical properties. RTCA studies showed sustained cell death with the formulations compared to the pure drug and placebo. The sequential drug release of the colon-targeted capsules containing 5-FU and LEU- loaded proniosomes showed negligible drug release in SGF (pH 1.2) and phosphate buffer solution (pH 6.8) (approximately 11 %) but profound drug release (>80 %) at pH 7.4. Drug-loaded proniosomes engineered for colon targeting (Eudragit S100 (10 %) capsules or Eudragit FS 30D capsules) showed good colon-specific targeting and favorable in vitro cytotoxicity profiles.

Using a combination of phospholipid fatty acids profiles and DNA-based sequencing analyses to detect shifts in the biofloc microbial community in different carbon sources and carbon/nitrogen ratios.

A 35-day study investigated the impact of carbon sources and carbon/nitrogen (C/N) ratios on the microbial community of biofloc. For this purpose, we utilized a combination of phospho-lipid fatty acids (PLFAs) profiles and DNA-based sequencing methods to investigate changes in the microbial community composition and structure. The experiment involved three carbon sources including Dextrin (DEX), corn starch (CS) and wheat bran (WB) at two C/N ratios (19 and 30). The results indicated that WB and CS were found to decrease nitrogen metabolite concentration while increasing total suspended solids and bacterial density compared to DEX. The treatments exhibited variations in microbial communities and the use of polymerase chain reaction/ denaturing gradient gel electrophoresis analysis revealed distinct dominant bacterial species linked to carbon sources and C/N ratios. Furthermore, the highest levels of bacteria and protozoa PLFAs biomarkers were observed in the C/N30 ratio and WB treatment while the ratio for poly-β-hydroxybutyrate/PLFAs and fungi biomarkers displayed a decrease. Also, by incorporating the results of PLFAs profile and conducting a principal component analysis, the treatments were categorized into distinct groups based on both the carbon source and C/N ratios. Overall, both methods yield consistent results. PLFAs offered additional insights into the microbial composition beyond bacterial structure while DNA-based analysis provided finer taxonomic resolution.

Indigestible Dextrin Alleviates the Intestinal Absorption of Alpha-linolenic Acid More Markedly Than That of Linoleic Acid in Obese Mice

Linoleic acid (LA) and alpha-linolenic acid (ALA) constitute the main dietary polyunsaturated fatty acids. Indigestible dextrin (DEX) is a dietary fiber that causes a beneficial decrease in lifestyle-related disease risk factors. We investigated the effects of DEX on intestinal absorption of LA and ALA in obese mice. KK-Ay/TaJcl obese mice were fed an ALA- or LA-abundant diet and provided with water in the absence and presence of 0.06 w/v% DEX for 4 weeks. The levels of lipids in serum samples and the lipase activity in serum and liver were analyzed. The effects of DEX on the intestinal absorption of LA and ALA were investigated using an in vitro model of the intestinal absorption process in the fed-state simulated intestinal fluid (FeSSIF) solution. ALA resulted in an increase in the serum triglyceride (TG) levels than those observed upon feeding an LA-abundant diet. DEX suppressed significantly the ALA-dependent increase in serum TG levels. Neither LA nor ALA affected the serum levels of total cholesterol and high-density lipoprotein cholesterol, as well as the serum and hepatic lipase activities. Moreover, ALA showed better solubility than LA in FeSSIF solution. The solubility of ALA in FeSSIF solution was significantly suppressed by DEX, whereas that of LA was not affected by DEX. ALA can be absorbed more easily than LA during the intestinal absorption process, probably leading to an increase in the serum TG levels and then DEX more selectively inhibits the intestinal absorption of ALA compared to that of LA.

Insulin-mediated glycemic responses and glucose homeostasis in black sea bream (Acanthopagrus schlegelii) fed different carbohydrate sources

The present study was conducted to investigate the effects of dietary carbohydrate sources on insulin mediated glycemic responses and glucose homeostasis in black seabream. Four isonitrogenous (48%) and isolipidic (12%) diets were formulated to contain 20% glucose (GLU), sucrose (SUC), dextrin (DEX) and wheat starch (WS), respectively. The black seabream was randomly distributed into 12 tanks (n = 3) at a stocking density of 12 fish per tank. After 2 weeks of feeding, fishes were starved for 48 h then re-fed and sampled at 0, 1, 3, 6, 12, and 24 h. The results showed that the concentration of serum glucose increased at 1 h, peaked at 3 h, decreased at 12 h, and returned to basal level at 24 h in all dietary groups (p < 0.05). In contrast, there were significant differences in postprandial insulin levels among all treatments, especially in the DEX group, which showed higher insulin level at 3 h after feeding (p < 0.05). Compared with 0 h, liver glycogen in the WS and DEX groups increase significantly at 6 h and was depleted at 24 h (p < 0.05). Hepatic enzyme activities such as glucokinase (GCK) and pyruvate kinase (PK) were influenced by sampling time and dietary carbohydrate sources (p < 0.05). Fish fed with the DEX diet showed the highest hepatic GCK and PK activities and the lowest phosphoenol pyruvate carboxykinase (PEPCK) activity at 3 h among all the treatments. Slightly but not significantly higher phosphofructo kinase (PFK) activity was observed in fish fed with the SUC diet than those fed with the GLU diet at 6 h post prandial (p > 0.05). The relative expression of insulin signaling pathways such as insulin receptor substrate1 (irs1) and protein kinase B (akt1) were significantly up-regulated at 3 h in the DEX group (p < 0.05). Meanwhile, the mRNA expression levels of glucokinase (gk) and pyruvate kinase (pk) were sensitive to hepatic glycolysis, and their expressions were up-regulated at 1, 3, 6 h, especially at 3 h in the DEX group. Genes such as glucose 6 phosphatase (g6pc) and phosphoenol pyruvate carboxykinase (pepck) played an important role in hepatic gluconeogenesis, and their expressions were inhibited at 1, 3 h. Overall, the results of present study indicated that dietary carbohydrate sources resulted in a hyperglycaemic situation 3 h after feeding, most likely as a response to glucose loading. Moreover, glucose metabolic responses were regulated by different carbohydrate sources at different time points, and plays a important role in clearing glucose through increased activity of insulin, glycolysis, and glycogenesis, along with gluconeogenesis suppression.

Review] Development of CLUSTER DEXTRIN&lt;sup&gt;®&lt;/sup&gt;-SE and Its Utilization

Review] Development of CLUSTER DEXTRIN&lt;sup&gt;®&lt;/sup&gt;-SE and Its Utilization

Effects of resistant dextrin on liver fat deposition and the AMPK signaling pathway in high-fat diet-fed mice

Objective To study the effects of resistant dextrin (RD) on liver fat deposition in high-fat diet-fed (HFD) mice, and to further explore whether it can regulate the AMPK signaling pathway. Methods Thirty-six 4-week-old male C57BL/6 mice were randomly divided into three groups: normal control group (chow), high-fat diet group (HFD), and high-fat diet+ resistant dextrin group (HFD+ RD, 10 g·kg-1·d-1). After 12 weeks of intervention, the liver tissues and serum samples were collected. Serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), aspartate aminotransferase (AST), alanine transaminase (ALT) levels and liver TG were measured. Liver tissue HE and oil red O staining were performed to observe hepatocyte steatosis and liver fat deposition. Quantitative real-time PCR was performed to detect the relative expression of fatty acid synthesis related genes SREBP1, ACC, SCD1 in the liver tissue, and Western blot was performed to detect relative protein levels of pAMPK, SREBP1, Fasn, and ACC in the liver. Results Compared with chow group, the body weight gain, fasting blood glucose (FBG), serum TC, LDL-C, HDL-C, and ALT levels were increased in HFD group (P<0.01), and serum AST level was also increased (P<0.05). Moreover, liver oil red O staining revealed that liver fat deposition was much more obvious in HFD group than that in chow group, and liver TG was also increased in HFD group (P<0.01). The mRNA levels of SREBP1 and ACC were increased in HFD group compared with that in chow group, and the protein level of pAMPK was reduced in HFD group (P<0.05). As compared with HFD group, the body weight gain, serum TG, TC, LDL-C, HDL-C and ALT levels were significantly reduced in RD group (P<0.01), and FBG level was also reduced (P<0.05). Moreover, RD treatment alleviated liver fat deposition and TG accumulation (P<0.01). The mRNA levels of SREBP1, ACC, and SCD1 were all reduced in RD group compared with HFD group. The protein level of pAMPK was increased, and the expression of Fasn was reduced with RD treatment (P<0.01). Conclusion Resistant dextrin improves liver fat deposition and activates the AMPK signaling pathway in HFD-fed mice. Key words: Resistant dextrin; Fatty liver; Liver fat deposition; Adenosine monophosphate-activated protein kinase

Combined inhibitory effect of calcium hypochlorite and dextrin on flotation behavior of pyrite and galena sulphides

Selective separation of pyrite from base minerals is very important and challenging. This research investigates the combined inhibitory effect of two novel reagents on flotation behaviors of pyrite and galena under the low alkaline conditions. The depression and adsorption mechanism of calcium hypochlorite [Ca(ClO)2] and dextrin (DX) on pyrite and galena were systematically studied via the microflotation experiments, reagent adsorption measurements and X-ray photoelectron spectroscopy. Flotation results showed that the combined effect of Ca(ClO)2 and DX depressed the flotation of pyrite more strongly than that of their individual effect. An improved recovery difference of more than 60% between the galena and pyrite was achieved at pH 10 while using Ca(ClO)2 and DX as depressant system and diethyldithiocarbamate (DDTC) as collector. Reagent adsorption measurements showed that the adsorption amount of DDTC onto pyrite surface was decreased significantly with the prior addition of Ca(ClO)2 and DX. On the contrary, the surface of galena remained mildly inert in the presence of Ca(ClO)2 and DX and thus adsorbed significantly more amount of DDTC. XPS analysis showed that, in the presence of Ca(ClO)2, the surface of pyrite was severely oxidized to iron oxide/hydroxide species that promoted the adsorption of DX onto the pyrite surface. Based on the XPS analysis, an adsorption and depression mechanism of Ca(ClO)2 and DX on pyrite and galena was also proposed.

Effect of microRNA-486 on alcoholic fatty liver disease in mice

Objective To investigate the effect of microRNA-486 (miR-486) on alcoholic fatty liver disease in mice. Methods The progenies of miR-486 knockout mice were obtained by mating of heterozygotes. The 8-week-old progenies were divided into miR-486 knockout control group (KO-PAIR group), miR-486 knockout experimental group (KO-ETOH group), wild type control group (WT-PAIR group) and wild type experimental group (WT-ETOH group), 8 mice in each group. Th mice in experimental group were fed on 5% TP4030D alcohol feed, and those in TP4030C control group were fed on control feed for 4 weeks, 15 ml/mouse per day. On the last day of the experiment, the alcohol group was given alcohol (31.5%) intragastrically, and the control group was administered with dextrin, 100 μl each mouse. After 9 h, the mice were sacrificed and their liver tissues and serum were collected. Liver tissue sections were stained with hematoxylin-eosin (HE) and saturated oil red O. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and tumor necrosis factor-α (TNF-α) were determined. The mRNA and protein expression levels of lipid metabolism related molecules adenosine monophosphate-activated protein kinase (AMPK) and acetyl-coA carboxylase-ser 79 (ACC) were detected by real-time fluorescence quantitative polymerization chain reaction and Western blotting, respectively. The severity of alcoholic fatty liver disease was evaluated and the mechanism was explored. Results HE staining and saturated oil red O staining showed that liver fatification was significantly aggravated in the WT-ETOH group as compared with the KO-ETOH group. As compared with the WT-ETOH group, serum levels of ALT, AST and TNF-α in the KO-ETOH group were significantly reduced [(124.875±38.591) U/L vs. (45.500±20.333) U/L, (190.750±23.789) U/L vs. (140.625±31.794) U/L, and (73.407±17.121) μg/L vs. (50.056±12.717) μg/L, F=32.503, 5.876 and 30.865, P<0.05]. The mRNA level of AMPK in the KO-ETOH group was significantly higher (0.61±0.09 vs. 1.06±0.11, F=21.249, P<0.01), and that of ACC was significantly lower (1.98±0.23 vs. 1.23±0.12, F=68.584, P<0.01) than in the WT-ETOH group, which was further confirmed by Western blotting (0.77±0.09 vs. 1.20±0.08, and 1.16±0.13 vs. 0.38±0.08, P<0.01). Conclusion Deficiency of miR-486 can alleviate alcoholic fatty liver disease in mice probably by regulating lipid metabolism. Key words: MicroRNA-486; Alcoholic fatty liver disease; Lipid metabolism

Optimization of preparation of Haoqin-Huaban granules

Objective To optimize the preparation process for Haoqin-Huaban granules so as to provide experimental basis for the development and utilization of the compound. Methods Taking the extraction rate of gentiopicroside from Gentiana macrophylla Pall as the observation index, L9(34)orthogonal test was used to investigate the amount of water, extraction time, and extraction frequency for optimizing the water extracting technology of the Haoqin-Huaban granules. Then the dry paste was used for the raw material, the ratio of the diluent (dextrin) and the concentration and dosage of the binder (ethanol) were investigated by single factor, and the particles were prepared. Results The optimum water extraction process was A2B2C3, which indicated that the prescribed medicinal materials with 8 times water were extracted 1 h for 3 times. The extract was concentrated into paste, vacuum drying, pulverizing, mixing according to the ratio of 5:1, with ethanol, made of soft material, pelletizing, drying at 60 ℃ for granulation, in order to make Haoqin-Huaban granules. Conclusions The preparation process is reasonable and feasible, which provides experimental basis for the industrial production of Haoqin-Huaban granules. Key words: Orthogonal test; Extraction; Gentiopicroside; Technology improving (TCD)

Studies on the Influenced of Dextrin Filler on the Mechanical Properties of Carboxylated Nitrile Butadiene Rubber (Xnbr) Films

Dextrin used in this experiment is a product of acidified sago starch being heated at high temperature. The use of dextrin as filler in latex films is to produce environmental friendly products. The synthesized dextrin dispersion was prepared by mechanical (ball milling). Dextrin (DX) is compounded with carboxylated nitrile butadiene rubber (XNBR) latex. The DX/XNBR films were prepared by incorporating dextrin at filler loading of 0, 5, 10, 15 and 20 phr into XNBR latex. The dextrin was then mixed with XNBR compound as a filler and a film was prepared by coagulant dipping technique The effect of dextrin loadings on tensile properties of XNBR films were investigated. The results indicated that the tensile properties such as tensile strength, elongation at break, and crosslink density decreased with increasing filler loading. The changes of functional groups present in native sago, dextrin and DX/XNBR film were characterized using Fourier Transform Infra-Red (FTIR). The morphological properties of tensile fractured surfaces of the samples were observed using Scanning Electron Microscope (SEM).

Preparation and characterization of an amylase-triggered dextrin-linked graphene oxide anticancer drug nanocarrier and its vascular permeability

We synthesized a dextrin (DEX)-conjugated graphene oxide (GO) nanocarrier (GO100-DEX) as a potential drug delivery system to respond to a tumor-associated stimulus, α-amylase, that has high permeability through the fenestrated endothelial barrier to the tumor site. At acidic pH and in the presence of α-amylase to simulate tumor conditions, GO100-DEX released a 1.5-fold higher amount of doxorubicin (DOX) than of GO100. Under the same conditions, the cytotoxic effects of GO100-DEX/DOX were 2-fold greater than those of free DOX and 2.9-fold greater than those of GO100/DOX. Employing an in vitro biomimetic microfluidic blood vessel model lined with human umbilical vein endothelial cells, we evaluated the tumor vasculature endothelial permeation of GO100-DEX and GO100 using dextrans of 10 and 70kDa for comparison and as standards to validate the microfluidic blood vessel model. The results showed that the permeabilities of GO100-DEX and GO100 were 4.3- and 4.9-fold greater than that of 70kDa dextran and 2.7- and 3.1-fold higher than that of 10kDa dextran, thus demonstrating the good permeability of the GO-based nanocarrier through the fenestrated endothelial barrier.

Effects of Dietary Carbohydrate Sources on Growth and Body Composition of Juvenile Abalone (Haliotis discus, Reeve)

ABSTRACT A 16-wk feeding trial was conducted to assess the effects of different types of dietary carbohydrate on growth and body composition of juvenile abalone (Haliotis discus). A total of 1,680 abalone were randomly distributed among 24 containers (70 per container) and fed one of eight diets, including seven experimental diets containing different types of carbohydrates, including dextrin (DT), glucose (GC), corn starch (CS), α-cellulose (CL), maltose (MT), sucrose (SC), and wheat flour (WF), and Undaria to compare effect of experimental diets. Water stability of the diets was measured 12, 24, and 48 h after seawater immersion. Water stability of the diets was different over all periods of time and their significant interaction was also observed. Survival was not significantly affected by diet. Weight gain and specific growth rate were greatest in abalone fed on the CL diet. Shell length, width, height, and soft body weight were greatest in abalone fed the CL diet, followed by the WF, DT, SC, CS, GC, ...

Effect of dietary carbohydrate sources on apparent nutrient digestibility of olive flounder (Paralichthys olivaceus) feed

Apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, nitrogen-free extract, and energy in selected carbohydrate sources including wheat flour (WF), α-potato starch (PS), α-corn starch (CS), Na alginate (AL), dextrin (DEX), and carboxymethyl cellulose (CMC) were determined for olive flounder. The olive flounder averaging 150 ± 8.0 g were held in 300-L tanks at a density of 30 fish per tank. Chromic oxide was used as the inert marker. Feces were collected from the flounder by a fecal collector attached to a fish rearing tank. Apparent dry matter and energy digestibilities of flounder fed WF, PS, CS, and DEX diets were significantly higher than those of fish fed AL and CMC diets. Apparent crude protein digestibility coefficients of flounder fed PS and CS diets were significantly higher than those of fish fed AL, DEX, and CMC diets. Apparent crude lipid and nitrogen-free extract digestibility coefficients of flounder fed PS and DEX diets were significantly higher than those of fish fed WF, CS, AL, and CMC diets. The present findings indicate that PS and DEX could be effectively used as dietary carbohydrate energy compared to WF, CS, AL, and CMC for olive flounder.

Citrus Bacterial Canker Pustules Are Associated With Leafminer Galleries IN IRAN

Citrus bacterial canker is one of the most destructive diseases of citrus in southern Iran. During 2000-2001 and 2005-2006, this disease became endemic showing a reduced severity. This was mainly due to the unfavorable climatic conditions, i.e. low rainfall during the previous years in particular. Control measures included pruning of symptomatic shoots and the use of copper sprays. In Rudan (Hormuzgan province), citrus pustules are usually observed on the lower leaf surface alongside the galleries caused by Phyllocnistis citrella. Bacteria were isolated from these pustules and identified as Xanthomonas citri pv. citri A (Xac) based on biochemical and physiological characteristics (Gram and oxidase reactions, nitrate reduction, urease, hydrolysis of aesculin, casein, gelatin, starch, Tween, sodium chloride tolerance, litmus milk, H2S generation from cysteine and phosphatase, xanthomonadin production, carbohydrate utilization); differential phenotypic features such as bacterial mass colour on Ayer medium containing L-proline, utilization of glycogen, maltose, dextrin, starch (Mohammadi et al., 2001); broad pathogenicity range on inoculated hosts including Mexican lime, unshu tangerine, sour orange, grapefruit and sweet orange. Larval leafminer damage results in elevated incidence and severity of citrus bacterial canker disease (Belasque et al., 2005). Since Ph. citrella is potentially capable of disseminating Xac, thus facilitating canker infection, it is suggested that controlling this pest may result in preventing Xac outbreaks in citrus groves. The association of bacterial canker pustules with leafminer tunnels has previously been reported from North Yemen and India (Cook, 1988; Belasque et al., 2005) but not in Iran, this constituting the first record.

Polymeric microparticles containing indomethacin for inhalatory administration

Indomethacin (IN) is a non-steroidal antiinflammatory drug. It reduces pain and inflammation in rheumatoid arthritis but its use is associated with high incidence of undesirable gastrointestinal side effects. In addition, its low solubility in water limits its oral bioavailability. In this work, microparticles based on an IN–polylysine (PL) complex were obtained by spray drying. The system is intended to deliver the drug through the inhalatory route for both local and systemic treatments. Several formulations, varying the relative composition IN/PL–dextrin (DX) and the total solid content of the feed solutions, were tested. The process performance (yield, air outlet temperature), product properties (IN load efficiency, moisture content, crystallinity, glass transition temperature, density, morphology and particle size distribution), the IN–polylysine ionic interaction (assessed by FT-infrared spectroscopy, powder X-ray diffraction and thermal analysis), and in vitro IN release were studied. Powders exhibited high load efficiencies and low moisture contents, and remained in the amorphous state after nine months of storage. The particle systems with 50% of the polylysine amino groups neutralized by IN were the more attractive ones for pulmonary treatment, since they were easily processed using a homogeneous aqueous feed, had relatively high IN contents and high cumulative fraction of respirable particles.

Novel PLA microspheres with hydrophilic and bioadhesive surfaces for the controlled delivery of fenretinide

Novel polylactide (PLA) microspheres endowed with hydrophilic and bioadhesive surfaces as injectable formulations for the controlled release of fenretinide were prepared, using a novel technique based on the co-precipitation of PLA with gelatin, at the interface of a liquid dispersion formed by the addition of N-methylpyrrolidone containing PLA and dextrin (DX), towards an aqueous solution of gelatin (G). The resulting PLA–G–DX microspheres were compared with others prepared by the same technique using polylactide-co-glycolide (PLGA), with or without DX, and with or without phosphatidylcholine. Of the different systems, the PLA–G–DX microspheres had the best morphological, dimensional and functional characteristics. They had the highest drug loading, and their drug release was the most efficient over time without any burst effect. Their in vitro anti-tumoural activity was strongly enhanced with respect to the pure fenretinide. This paralleled the increased drug concentration inside the cells due to their marked bioadhesion to the tumour cell membranes as indicated by scanning electron microscope images.

Starch addition in renneted milk gels: Partitioning between curd and whey and effect on curd syneresis and gel microstructure

Milk gels were made by renneting and acidifying skim milk containing 5 different starches, and then compressed by centrifugation to express whey and simulate curd syneresis during the manufacture of low-fat cheese. A series of 17 starches were examined, with 5 starches being selected for in-depth analysis: a modified waxy corn starch (WC), a waxy rice starch (WR), an instant tapioca starch (IT), a modified tapioca starch (MT), and dextrin (DX). Milks containing WC, WR, and DX were given a 72°C heat treatment, whereas those containing IT and MT had a 30-min treatment at 66°C that matched their optimum gelatinization treatments. Curd yields were calculated by weight, estimated starch content in whey was measured gravimetrically by alcohol precipitation, and starch retention in curd was calculated. Curd yields were 13.1% for the control milk (no added starch) and 18.4, 20.7, 21.5, 23.5, and 13.2% for the gels containing starches WC, WR, IT, MT, and DX, respectively. Estimated starch retentions in the curd were, respectively, 71, 90, 90, 21, and 1%. Laser scanning confocal microscopy was used to determine the location of the starches in the curd and their interaction with the protein matrix. Waxy corn, WR, and IT starches have potential to improve texture of low-fat cheese because they had high retention in the curd and they generated interruptions in the protein matrix network that may have helped limit extensive protein-protein interactions. Modified tapioca starch interfered with formation of the protein structure of the curd and produced a soft noncohesive gel, even though most (79%) of the MT starch was lost in the whey. Few distinct starch particles were present in the MT curd network. Dextrin was not retained in the curd and did not disrupt the protein network, making it unsuitable for use in low-fat cheese.

Antitumor activity of fenretinide encapsulated in novel based PLA microspheres

Several studies reported fenretinide (4-HPR) can be used as antitumoral drug in many types of cancer cell lines such as neuroblastoma, mammary carcinoma and melanoma. In vitro 4-HPR inhibits growth of neuroblastoma in a dose dependent manner with an high antitumor activity at 5–10 μM (Ponzoni et al., 1995).The main disadvantage of 4HPR in clinical application is its lipophilic behavior which hinders the possibility to maintain therapeutic concentration for long period of time. To bypass this drawback, new drug delivery systems consisting in polylactide (PLA) or polylactide-co-glycolid (PLGA) microspheres were developd. A novel solvent extraction method based on the co-precipitation of PLA or PLGA with gelatin has been utilized. Phosphatidylcholine (PC) or dextrin (DX) were added to improve the hydrophilic character of the microsphere surface. After a preliminary study of physical characteristics in terms of encapsulation efficiency, mean size and release profile of drug, PLA/gelatin/dextrin MS were chosen to test the antitumor activity in SH-SY5Y neuroblastoma cell line. After 3 and 24 hours of treatment a cell viability of 50 % and 0% was observed respectively. Empty MS did not affect the cell viability at the same time points. High resolution SEM showed an high bioadhesion of PLA/gelatin/dextrin microspheres to cell membrane. Cell uptake experiments demonstrated an high intracellular concentrations of fenretinide in the presence of the PLA/gelatin/dextrin microspheres rather than in the presence of pure fenretinide. In conclusion, 4-HPR loaded in PLA/gelatin/dextrin microspheres represent a powerful tool for drug delivery systems for hydrophobic antitumor drugs whose therapeutic potential is hindered by their low availability.

Effects of Carbohydrate and Water Temperature on Nutrient and Energy Digestibility of Juvenile and Grower Rockfish, Sebastes schlegeli

A factorial (4×2×2) experimental design was employed to determine apparent digestibilities of dry matter (DM), protein, lipid, energy and nitrogen-free extract (NFE) of the test diets containing either α-potato starch (A-PS), β-potato starch (B-PS), β-corn starch (B-CS) or dextrin (DEX) as dietary carbohydrate energy for juvenile (average weight 30 g) and grower (average weight 300 g) rockfish reared at 13°C and 20°C. Chromic oxide was used as an inert marker. Feces were collected by fecal collectors attached to rearing tanks from triplicate groups of juvenile and grower rockfish. Digestibilities of DM, energy and NFE of the test diets were significantly affected by dietary carbohydrate and water temperature (p<0.01), but not by fish size. DM digestibility of the fish fed the A-PS diet was significantly higher than that of fish fed other treatments, except for the DEX diet at 20°C. DM digestibility of rockfish fed the B-CS diet was significantly lower than that of other diets. A similar pattern was observed in apparent digestibility of energy. NFE digestibility of fish fed the test diets was significantly affected by carbohydrate and significantly correlated to DM (r = 0.97, p<0.01) and energy (r = 0.99, p<0.01) digestibilities, regardless of water temperature and fish size. NFE digestibility of the fish fed the β-starch diets was relatively lower compared to that of the α-starch diets, and ranged from 35 to 43% and 20 to 27% for B-PS and B-CS, respectively. The present findings indicate that carbohydrate and water temperature significantly affected digestibilities of dry matter, energy and nitrogen-free extract of rockfish. Among dietary carbohydrates, α-potato starch could be effectively used as dietary carbohydrate energy for rockfish at 13°C and 20°C. (Key Words : Rockfish, Sebastes schlegeli, Carbohydrate, Water Temperature, Digestibility)