Changes in Production Parameters, Egg Qualities, Fecal Volatile Fatty Acids, Nutrient Digestibility, and Plasma Parameters in Laying Hens Exposed to Ambient Temperature.

The present study was undertaken to investigate the impact of heat stress on nutrient digestibility and tibia and reproductive traits, and changes in laying performance, egg qualities, fecal volatile fatty acids, and plasma parameters in laying hens. One-hundred twenty 52-week-old laying hens were raised in three temperature-controlled facilities with constant humidity (50% RH), either normal temperature (LT; 22°C) or heat stress considered being moderate (MT; 27°C) or severe (HT; 32°C) for 42 days. Feed intakes were consistently low (p < 0.01) in HT hens compared with those in LT or MT over the period of 42 days. Egg production kept markedly (p < 0.05) or numerically (p > 0.05) low in hens exposed to HT vs. LT or MT. Egg mass and egg weight were consistently low (p < 0.01) in hens exposed to HT compared with those raised under LT or MT. On the other hand, feed conversion ratio and frequency of dirty and cracked eggs were not significantly affected (p > 0.05) during the experimental period. HT-exposed hens consistently had lowered (p < 0.05) eggshell thickness and breaking strength, eggshell weight, and plasma Ca, P, and Mg levels compared with LT- or MT-treated hens. HT hens had lower (p < 0.01) relative oviduct weight and less number of large yellow follicles compared with those raised under LT or MT conditions at 42 days. Tibia traits measured at 42 days were not affected by any of heat treatments. Fecal volatile fatty acids tended to be higher in HT-exposed laying hens throughout the experiment. It was noted that digestibilities of neutral detergent fiber and dry matter were lowest (p < 0.05) in hens exposed to HT vs. LT or MT environments. Our study suggests that heat stress could lower laying performance, egg quality, and physiological parameters that are coupled with alterations in gut metabolites and mineral/lipid metabolism. The findings emerged from this study will help us design the nutritional and environmental strategies to mitigate the negative effect of heat stress on laying hens.

Evaluation of energy and amino acids of brown rice and its effects on laying performance and egg quality of layers.

Two experiments were conducted to determine apparent metabolizable energy (AME), nitrogen-corrected AME (AMEn), and ileal digestible amino acid (AA) content of brown rice (BR) and to investigate the effect of dietary supplementation of BR on laying performance and egg quality of laying hens. In Exp. 1, 72 Hy-line Brown layers (49-week-old) were allocated to two treatments using a completely randomized block design, and each treatment included six cages per treatment and six hens per cage. A semi-purified diet was formulated to include BR as the sole source of AA and energy and an N-free diet was used to determine basal endogenous loss of AA. The hens were fed a commercial layer diet for adaptation to the experimental environment and diet for 7 days from d 0, and then fed experimental diets for 5 days from d 7. Excreta were collected from d 10 to 11 and ileal digesta were collected on d 12. On a dry matter (DM) basis, the AME and AMEn of BR was determined at 3,773 and 3,729 kcal/kg, respectively. The apparent ileal digestibility (AID) of BR ranged from 32.7% for Thr to 73.7% for Arg. The range of the standardized ileal digestibility (SID) value was between 79.4% for Met and 96.6% for Lys. In Exp. 2, 252 Hy-line Brown layers (44-week-old) were divided into four groups, comprising seven replicates of nine birds each and assigned to four experimental diets containing 0 (Control), 5%, 10%, or 15% BR for 5 weeks. The BR-containing diets were formulated to be equal in the content of AMEn and digestible AA to those of the diet without BR. No significant differences were observed in laying performances. Egg quality and blood profiles were not linearly or quadratically affected by dietary treatments. These results suggest that up to 15% BR can be included into layer feed without any adverse effects on laying performance and egg quality, if its energy and digestible AA values are well evaluated.

Influence of carbon type and carbon to nitrogen ratio on the biochemical methane potential, pH, and ammonia nitrogen in anaerobic digestion.

Organic waste used as a feedstock in the anaerobic digestion (AD), it includes carbon and nitrogen. Carbon and nitrogen have an effect on the various digestive characteristics during AD, however, the study is rare about those of the interaction. This study investigates the influence of carbon type and carbon to nitrogens (C/N ratios) on the AD characteristics of organic waste. Experimental treatments involved a combination of three carbon types with three C/N ratios. The AD tests were carried out using a 125-mL serum bottle at a constant temperature of 37°C and moisture 95% for 18 days. Degradation pattern shows the difference among three-carbon treatments, the starch group was faster than other groups. Maximum methane production date was similar between starch (9.96 ± 0.05 day) and xylan group (10.0 ± 0.52 day), those of the cellulose group (14.6 ± 1.80 day) was slower than other groups (p < 0.05). The lag phase was only affected by the carbon type (p < 0.05). Ammonia nitrogen was mainly affected by nitrogen concentration regardless of carbon type (p < 0.05). This study showed that xylan is useful as feedstock in order to decrease the lag phase, and it showed that ammonia was independently affected by the nitrogen concentration.

Pediococcus spp.-fermented chicken meat for dogs.

An experiment was conducted to evaluate Pediococcus spp.-fermented chicken meat as a snack for dogs. The fermented or non-fermented snacks used in this study were prepared through the following process; meat mixtures containing 52.8% MDCM, 35.2% chicken breast meat (CBM) and 9.7% corn starch were inoculated with or without Pediococcus spp., incubated at 37°C for 24 h and then sterilized at 121°C for 20 min. During the 24-h fermentation, the pH of fermented chicken snack dropped rapidly with concomitant increase in number of lactic acid bacteria. The nutritional composition was not altered by fermentation. In vitro pepsin nitrogen digestibility was higher (p < 0.05) in the fermented snack compared with the non-fermented snack. Upon storage at room temperature for 14 days, bacteria grew slowly in fermented vs. non-fermented snack samples. In a palatability trial, dogs preferred non-fermented over fermented snack food. In 12-d-long feeding trial, fecal ammonia content was lowered, but fecal lactic acid content was increased in dogs fed the fermented vs. non-fermented snack food. Our study shows that the fermented MDCM-based snack exhibited good preservability upon storage, and improved in vitro nitrogen digestibility and fecal characteristics in dogs.

Effects of Low-Protein Diets and Exogenous Protease on Growth Performance, Carcass Traits, Intestinal Morphology, Cecal Volatile Fatty Acids and Serum Parameters in Broilers.

Dietary exogenous proteases (ENZ) can be used in poultry production to improve the growth of chickens fed low-protein (LP) diets. We hypothesized that ENZ supplemented in an LP diet would improve growth performance and physiological response in broilers for 8-35 days. To investigate this, we used a 2 × 2 factorial design with crude protein (CP, normal diet (NP) and LP) and ENZ. The LP diet contained low in 1% CP and ca. 8-12% amino acids compared to the NP diet and both NP and LP diets were added without or with (1 g/kg of diet) ENZ. We randomly allocated 720 1-week-old Ross 308 male chicks to 48 pens and experimental diets. At 21 days, dietary ENZ, but not CP, increased (p = 0.007) live body weight. Body weight gain from 8-21 days was affected (p = 0.006) by dietary ENZ, but was not affected (p = 0.210) by CP. The feed conversion ratio was affected by both CP and ENZ during the starter period (p < 0.05), by ENZ (p = 0.034) during the finisher period, and by CP (p < 0.001) during the whole period. However, the interaction between CP and ENZ did not significantly affect growth performance (p > 0.05). Dietary ENZ increased (p = 0.013) the relative weight of liver at 21 days. CP and ENZ affected (p = 0.043) total short-chain fatty acids at 21 days. However, this effect was not seen (p = 0.888) at 35 days. Dietary CP increased (p < 0.05) the serum concentrations of both uric acid and creatinine in broilers. We concluded that dietary ENZ is more beneficial to younger broilers, independent of CP levels, and that its effect was restricted to body weight and the feed conversion ratio.

Effects of transport stress on physiological responses and milk production in lactating dairy cows.

OBJECTIVE: This study was conducted to investigate the effect of transport stress on physiological and hematological responses and milk performance in lactating dairy cows. METHODS: Ten lactating dairy cows were randomly divided into 2 groups. The treatment group (TG) was transported 200 km for 4 h by truck, and the control group (NTG) was restrained by stanchion for 4 h in Konkuk University farm. Blood and milk samples were collected at 24 h pre-transport; 1, 2, and 4 h during transport; and 2, 24, and 48 h post-transport. Milk yields were measured at 24 h pre-transport, 0 h during transport, and 24, 48, and 72 h post-transport. RESULTS: Leukocyte, neutrophil, and monocyte numbers in the TG were significantly higher than those of the NTG at each experimental time point. Lymphocyte numbers in the TG were significantly (p<0.05) higher than those of the NTG at 48 h post-transport. Additionally, the neutrophil:lymphocyte ratio of the TG was 45% and 46% higher than that of the NTG at 4 h during transport and 2 h post-transport, respectively. There were no significant differences in erythrocyte numbers, hemoglobin concentrations, platelet numbers, and hematocrit percentages between two groups. Cortisol levels in the TG were significantly (p<0.05) higher than those in the NTG. Milk yields in the TG were lower than those in the NTG. The somatic cell count (SCC) of the TG was significantly (p<0.05) higher than that of the NTG at 1 and 2 h during transport; that of the TG increased dramatically at 1 h during transport and gradually decreased subsequently. CONCLUSION: Transport stress increased blood parameters including leucocyte, neutrophil, and monocyte numbers by increased cortisol levels, but did not affect erythrocytes, hemoglobin and hematocrit levels. Additionally, transport resulted in a decrease in milk yield and reduced milk quality owing to an increase in milk SCC.

Effects of dietary supplementation with fermented and non-fermented brown algae by-products on laying performance, egg quality, and blood profile in laying hens.

OBJECTIVE: This study was conducted to investigate the effects of dietary supplementation with fermented and non-fermented brown algae by-products on the laying performance, egg quality, relative organ weight, and blood profile of laying hens. METHODS: Hy-Line Brown chickens (n = 180; 70-week-old) were randomly divided into 5 groups with 4 replicates per group (3 hens per cage, 4 cages per replicate), and fed with 5 experimental diets, namely the basal control diet (CON) or the control diet supplemented with 0.5% brown seaweed (BS), 0.5% seaweed fusiforme (SF), 0.5% fermented brown seaweed (FBS), or 0.5% fermented seaweed fusiforme (FSF), for 4 weeks. RESULTS: Egg production rate and egg mass were greater in the BS group than in the other groups (p<0.05), and the SF and FSF groups had greater egg production than the control group (p<0.05). Egg weight was higher in the BS group than in the other groups (p<0.05). There were no differences in eggshell color, egg yolk color, eggshell strength, or eggshell thickness among the groups. There was no difference in Haugh units among the treatment groups, except for the FSF group, which had a significantly lower value (p<0.05). The non-fermented groups had greater relative organ weights, particularly the liver and cecum, than the other groups (p<0.05). Regarding blood profile, the supplemented-diet groups had higher albumin levels than the control group (p<0.05). The FBS group had higher total cholesterol and triglyceride levels than the other groups (p<0.05). The BS and FBS groups had higher glutamic pyruvic transaminase levels than the other groups (p<0.05). CONCLUSION: This study demonstrated that dietary brown algae supplementation can improve egg-laying performance; however, supplementation with fermented seaweeds had no positive effect on the egg-laying performance of hens.

Effects of feeding level on nutrient digestibility and enteric methane production in growing goats (Capra hircus hircus) and Sika deer (Cervus nippon hortulorum)

Objective: Two experiments were conducted to determine the effects of feeding level on nutrient digestibility and enteric methane (CH4) emissions in growing goats and Sika deer. METHODS: Three growing male goats (initial body weight [BW] of 22.4±0.9 kg) and three growing male deer (initial BW of 20.2±4.8 kg) were each allotted to a respiration-metabolism chamber for an adaptation period of 7 d and a data collection period of 3 d. An experimental diet was offered to each animal at one of three feeding levels (1.5%, 2.0%, and 2.5% of BW) in a 3×3 Latin square design. The chambers were used for measuring enteric CH4 emission. RESULTS: Nutrient digestibility decreased linearly in goats as feeding level increased, whereas Sika deer digestibility was not affected by feeding level. The enteric production of CH4 expressed as g/kg dry matter intake (DMI), g/kg organic matter intake, and % of gross energy intake decreased linearly with increased feeding level in goats; however, that of Sika deer was not affected by feeding level. Six equations were estimated for predicting the enteric CH4 emission from goats and Sika deer. For goat, equation 1 was found to be of the highest accuracy: CH4 (g/d) = 6.2 (±14.1)+10.2 (±7.01)×DMI (kg/d)+0.0048 (±0.0275)×dry matter digestibility (DMD, g/kg)-0.0070 (±0.0187)×neutral detergent fiber digestibility (NDFD; g/kg). For Sika deer, equation 4 was found to be of the highest accuracy: CH4 (g/d) = -13.0 (±30.8)+29.4 (±3.93)×DMI (kg/d)+0.046 (0.094)×DMD (g/kg)-0.0363 (±0.0636)×NDFD (g/kg). CONCLUSION: Increasing the feeding level increased CH4 production in both goats and Sika deer, and predictive models of enteric CH4 production by goats and Sika deer were estimated.

Effects of dietary fermented spent coffee ground on nutrient digestibility and nitrogen utilization in sheep.

OBJECTIVE: The objective of the study was to determine the effect of fermented spent coffee ground (FSCG) on nutrient digestibility and nitrogen utilization in sheep. METHODS: Fermentation of spent coffee ground (SCG) was conducted using Lactobacillus plantrum. Fermentation was performed at moisture content of 70% and temperature of 39°C with anaerobic air tension for 48 h. Four adult rams (initial body weight = 56.8±0.4 kg) were housed in a respiration-metabolism chamber and the treatments were: i) control (Basal diet; 0% SCG or FSCG), ii) 10% level of SCG, iii) 10% level of FSCG, and iv) 20% level of FSCG in 4×4 Latin square design. Each dietary experiment period lasted for 18-d with a 14-d of adaptation period and a 4-d of sample collection period. RESULTS: In SCG fermentation experimental result, acid detergent insoluble nitrogen (ADIN) concentration of FSCG (64.5% of total N) was lower than that of non-fermented SCG (78.8% of total N). Digestibility of dry matter and organic matter was similar among treatment groups. Although crude protein (CP) digestibility of the control was greater than FSCG groups (p< 0.05), the 10% FSCG group showed greater CP digestibility and nitrogen retention than non-fermented 10% SCG group (p<0.05). Body weight gain and average daily gain were linearly decreased with increasing FSCG feeding level (p<0.05). When the feeding level of FSCG was increased, water intake was linearly increased (p<0.05). With an increasing FSCG level, dry matter intake did not differ among groups, although the gain to feed ratio tended to decrease with increasing level of FSCG (p<0.10). CONCLUSION: Microbial fermentation of SCG can improve protein digestibility, thereby increasing CP digestibility and nitrogen utilization in sheep. Fermentation using microorganisms in feed ingredients with low digestibility could have a positive effect on improving the quality of raw feed.

Effects of dietary forage-to-concentrate ratio on nutrient digestibility and enteric methane production in growing goats (Capra hircus hircus) and Sika deer (Cervus nippon hortulorum).

OBJECTIVE: Two experiments were conducted to determine the effects of forage-to-concentrate (F:C) ratio on the nutrient digestibility and enteric methane (CH4) emission in growing goats and Sika deer. METHODS: Three male growing goats (body weight [BW] = 19.0±0.7 kg) and three male growing deer (BW = 19.3±1.2 kg) were respectively allotted to a 3×3 Latin square design with an adaptation period of 7 d and a data collection period of 3 d. Respiration-metabolism chambers were used for measuring the enteric CH4 emission. Treatments of low (25:75), moderate (50:50), and high (73:27) F:C ratios were given to both goats and Sika deer. RESULTS: Dry matter (DM) and organic matter (OM) digestibility decreased linearly with increasing F:C ratio in both goats and Sika deer. In both goats and Sika deer, the CH4 emissions expressed as g/d, g/kg BW0.75, % of gross energy intake, g/kg DM intake (DMI), and g/kg OM intake (OMI) decreased linearly as the F:C ratio increased, however, the CH4 emissions expressed as g/kg digested DMI and OMI were not affected by the F:C ratio. Eight equations were derived for predicting the enteric CH4 emission from goats and Sika deer. For goat, equation 1 was found to be of the highest accuracy: CH4 (g/d) = 3.36+4.71×DMI (kg/d)-0.0036×neutral detergent fiber concentrate (NDFC, g/kg)+0.01563×dry matter digestibility (DMD, g/kg)-0.0108×neutral detergent fiber digestibility (NDFD, g/kg). For Sika deer, equation 5 was found to be of the highest accuracy: CH4 (g/d) = 66.3+27.7×DMI (kg/d)-5.91×NDFC (g/kg)-7.11× DMD (g/kg)+0.0809×NDFD (g/kg). CONCLUSION: Digested nutrient intake could be considered when determining the CH4 generation factor in goats and Sika deer. Finally, the enteric CH4 prediction model for goats and Sika deer were estimated.

Characteristics of Rice Hulls, Sawdust, Wood Shavings and Mixture of Sawdust and Wood Shavings, and Their Usefulness According to the Pen Location for Hanwoo Cattle.

In this study, two experiments were conducted to investigate the physicochemical characteristics (Exp. I) of bedding materials such as rice hulls (RH), sawdust (SD), wood shavings (WS) and sawdust+wood shavings (S+W; 1:1 in volume), and utilization of these beddings except RH (Exp. II) for rearing beef cattle. In Exp. I, the distribution of particle size (%) with 250 µm and below 250 µm was greater (p<0.05) in SD (30.4) than RH (4.4), WS (18.8) and S+W (20.1). Bulk density (kg/m(3)) of bedding materials was directly proportional to the percentage of 250 µm and below 250 µm particles, 178, 46, 112, and 88 for SD, WD, S+W and RH, respectively. Water absorption rate (%) after submersion in water for 24 h was higher (p<0.05) in WS (540.2) compared to SD (270.2), S+W (368.2). The S+W had an intermediate value of the absorption rate between SD and WS, but had an outstanding durability of water absorption capacity. Moisture evaporation rate (%) for 12 h was higher (p<0.05) in WS (75.4) than SD (70.5), S+W (72.2) and RH (57.8). Average ammonia emission (mg/m(2)/h) for 36 h was higher (p<0.05) in RH (3.15) than SD (1.70), WS (1.63), and S+W (1.73). In Exp. II, thirty six Hanwoo cows were allocated in 9 pens with one side on feed bunk side (Side A) and another side equipped with water supply (Side B) for 3 weeks with duplicated periods. Average moisture concentrations (%) of beddings were higher (p<0.05) in WS (side A, 65.7; side B, 57.9) than SD (side A, 62.5; side B, 52.2) and S+W (side A, 61.6; side B, 50.7). Regardless of types of beddings, moisture concentrations (%) of beddings within a pen were lower (p<0.05) at side B than A, implying longer period of utilization. These results suggest that using S+W would be a better choice than SD or WS alone, considering physicochemical characteristics and economics, and RH is not a suitable material as a bedding for beef cattle.

Protective Effect of Areca catechu Leaf Ethanol Extract Against Ethanol-Induced Gastric Ulcers in ICR Mice.

Gastric ulcer is a common digestive disorder that results in considerable suffering. Hence, this digestive pathology has been the focus of a number of recent studies. Although numerous drugs have been developed to treat gastric ulcers, therapeutic approaches for many of the complications associated with these drugs remain to be identified. For this reason, many natural compounds have been explored as alternatives for these drugs. In this study, we have investigated the effectiveness of Areca catechu leaf ethanol extract (ACE) for treating ethanol-induced gastric ulcers in mice. We performed histological as well as immunohistochemical examinations to explore the therapeutic properties of ACE. We also examined the levels of inflammatory signaling molecules to confirm the anti-inflammatory effects of ACE. The histochemical data demonstrate that ACE can protect the mucosal epithelium as well as the vascular supply in the gastric tract. Furthermore, ACE significantly reduced the expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 receptor (IL-6R), inducible NO synthase (iNOS), cyclooxygenase 2 (COX2), and nuclear factor-kappa B (NF-κB). Taken together, these data suggest that ACE administration may have the potential as an alternative treatment for gastric ulcer because of its cytoprotective and anti-inflammatory effects and ability to promote the rejuvenation and revascularization of the damaged gastric epithelium.

Effects of dietary trans-9 octadecenoic acid, trans-11 vaccenic acid and cis-9, trans-11 conjugated linoleic acid in mice.

The aim of the present study was to investigate the effects of dietary trans fatty acids in mice. Following the administration of a 0.5/100 g diet of trans-9 octadecenoic acid (EA), trans-11 vaccenic acid (TVA) or cis-9, trans-11 conjugated linoleic acid (CLA) for 4 weeks, the body weights and the weights of the liver, testis and mediastinal adipose tissue (MAT) of the animals gradually decreased (P<0.05). The EA group exhibited the lowest levels of magnesium and triglycerides (P<0.05). CLA increased villus length (P<0.05), while EA and TVA decreased villus length (P<0.05). The TVA group exhibited the lowest levels of low-density lipoprotein and tumor necrosis factor-α (P<0.05). Taken together, EA, TVA and CLA affected the physiological conditions of mice differently. The potential effects of three well-known fatty acids, including trans-9 octadecenoic acid (EA), trans-11 vaccenic acid (TVA) and cis-9, trans-11 conjugated linoleic acid (CLA), in animals or humans remain to be elucidated. Therefore, in the present study, 32 animals were randomly divided into four groups and administered a 0.5/100 g diet of EA, TVA or CLA for 4 weeks. The results demonstrated that the body weights and the weights of the liver, testis and mediastinal adipose tissue (MAT) of the animals gradually decreased (P<0.05). Blood was collected individually via the external jugular veins and the EA group exhibited the lowest levels of magnesium and triglycerides (P<0.05). CLA increased villus length (P<0.05), while EA and TVA decreased villus length (P<0.05). The TVA group exhibited the lowest levels of low-density lipoprotein and tumor necrosis factor-α (P<0.05). Taken together, EA, TVA and CLA affected the physiological conditions of mice differently and these may further our understanding of the various effects of these fatty acids on animals and humans.

Effects of Light Color on Energy Expenditure and Behavior in Broiler Chickens.

This study was conducted in order to investigate whether the presence of light or different colors of light would influence the energy expenditure and behavior of broiler chickens. Eight 8-week-old broiler chickens were adapted to a respiration chamber (Length, 28.5 cm; Height, 38.5 cm; Width, 44.0 cm) for one week prior to the initiation of the experiment. In experiment 1, energy expenditure and behavior of the chickens were analyzed in the presence or absence of light for four days. Chickens were exposed to 6 cycles of 2 h light/2 h dark period per day. In experiment 2, the broiler chickens that had been used in experiment 1 were used to evaluate the effect of 4 different wavelength light-emitting diodes (LEDs) on the energy expenditure and behavior of broiler chickens. The LEDs used in this study had the following wavelength bands; white (control), red (618 to 635 nm), green (515 to 530 nm) and blue (450 to 470 nm). The chickens were randomly exposed to a 2-h LED light in a random and sequential order per day for 3 days. Oxygen consumption and carbon dioxide production of the chickens were recorded using an open-circuit calorimeter system, and energy expenditure was calculated based on the collected data. The behavior of the chickens was analyzed based on following categories i.e., resting, standing, and pecking, and closed-circuit television was used to record these behavioral postures. The analysis of data from experiment 1 showed that the energy expenditure was higher (p<0.001) in chickens under light condition compared with those under dark condition. The chickens spent more time with pecking during a light period, but they frequently exhibited resting during a dark period. Experiment 2 showed that there was no significant difference in terms of energy expenditure and behavior based on the color of light (white, red, green, and blue) to which the chickens were exposed. In conclusion, the energy expenditure and behavior of broiler chickens were found to be strongly affected by the presence of light. On the other hand, there was no discernible difference in their energy expenditure and behavior of broiler chickens exposed to the different LED lights.

Antitumor effect of adriamycin-encapsulated nanoparticles of poly(DL-lactide-co-glycolide)-grafted dextran.

In this study, we prepared adriamycin (ADR)-encapsulated core-shell type nanoparticles of a poly(DL-lactide-co-glycolide) (PLGA) grafted-dextran (DexLG) copolymer and evaluated its antitumor activity in vitro and in vivo. The particle size of ADR-encapsulated DexLG nanoparticles was around 50-200 nm and the morphology was spherical shapes at transmission electron microscopy (TEM) observation. Since reconstitution of lyophilized nanoparticles is essential to practical use in vivo, ADR-encapsulated DexLG nanoparticles were lyophilized and reconstituted them into deionized water. Although reconstitution process caused increase of particle size, drug release behavior of nanoparticles was not significantly changed before and after reconstitution process. The ADR-encapsulated DexLG nanoparticles were less cytotoxic than free ADR plus empty nanoparticles at in vitro, while empty DexLG nanoparticles did not significantly affect cell viability. Even if free ADR plus empty nanoparticles are most effective to inhibit tumor growth at tumor-induced animal model using CT-26 cells, ADR-encapsulated DexLG nanoparticles showed increased survivability of mice. These results indicated that ADR-encapsulated DexLG nanoparticles are promising vehicles for antitumor drug delivery.

Cytotoxicity of amphotericin B-incorporated polymeric micelles composed of poly(DL-lactide-co-glycolide)/dextran graft copolymer.

In this study, we prepared amphotericin B (AmpB)-encapsulated polymeric micelle of poly(DL-lactideco-glycolide) (PLGA) grafted-dextran (DexLG) copolymer for the cytotoxicity test. The average particle size of AmpB-encapsulated DexLG polymeric micelles was around 30 approximately 70 nm and their morphology showed spherical shapes. Since aggregation states of AmpB are related to intrinsic cytotoxicity, prevention of AmpB aggregation in aqueous solution will provide low cytotoxicity and increased antimicrobial activity for the infectious disease. At UV/VIS spectrum measurement, polymeric micelle prepared from methanol/water mixture (method B) showed a monomeric state of AmpB while polymeric micelle prepared from DMSO (method A) showed an aggregated state. During the hemolysis activity test, polymeric micelle from method B showed reduced hemolysis activity compared to AmpB itself and polymeric micelle from method A. These results indicated that AmpB-incorporated polymeric micelle prepared from methanol/water mixture has low cytotoxicity and favorable antimicrobial activity.