ABSTRACT
In this study, the effect of the steps involved in zona-free somatic cell nuclear transfer (SCNT) on oocyte transcripts was investigated in sheep. To establish the reliable combined electrical-chemical activation for zona-free oocytes, oocytes were first exposed to an electrical pulse and then treated with 18 chemical activation regimens designed through modifying duration and concentration of ionomycin and 6-dimethyl aminopurine (6-DMAP), which is routinely used for SCNT. Electrofusion-mediated nuclear transfer significantly reduced transcript abundances of CCNB1, POU5F1, NPM2, GMMN, and CX43 compared to intact oocytes. Maximum parthenogenetic blastocyst development was obtained when oocytes were submitted to electric pulse and then to (1) 5 µM ionomycin for 5 or 2.5 min, both followed by 2 h of incubation with 6-DMAP (41.7±1.1, and 42.4±1.4%, respectively), (2) 5 µM ionomycin for 1 min+6-DMAP for 4 h (43.1±1.4%), and (3) 2.5 µM ionomycin for 1 min+6-DMAP for 2 h (42.4±1.4%), with significant differences compared to all the other groups. Statistical assessment of interactions between duration and concentration of ionomycin and duration of 6-DMAP exposure revealed that (1) concentration of ionomycin may be a more important factor than its duration, (2) both a long exposure period and a low concentration of ionomycin had marked decreasing effects on parthenogenetic development of zona-free oocytes, and (3) high duration of exposure to 6-DMAP can reduce parthenogenetic development. Despite an activation preference of parthenogenetic oocytes, a significantly higher rate of cloned blastocyst development was observed when reconstructed oocytes were activated with 5 µM ionomycin for 5 min rather than 2.5 µM ionomycin for 1 min (8.8±2.5 vs. 1.25±2.2%). These results suggested that SCNT steps have determining effects on oocyte transcripts and activation preferences of the reconstituted oocytes compared to intact counterparts. In this sense, reconstituted oocytes may need a higher concentration of ionomycin for a longer period than intact oocytes.
Subject(s)
Adenine/analogs & derivatives , Ionomycin/pharmacology , Nuclear Transfer Techniques , Oocytes/physiology , Zona Pellucida , Adenine/pharmacology , Animals , Blastocyst/drug effects , Blastocyst/physiology , Calcium Ionophores/pharmacology , Cells, Cultured , Dose-Response Relationship, Drug , Electric Stimulation , Female , In Vitro Techniques , Models, Animal , Oocytes/drug effects , Parthenogenesis/drug effects , Parthenogenesis/physiology , Protein Kinase Inhibitors/pharmacology , SheepABSTRACT
The objective of the present study was to prepare a polymeric drug delivery system with no burst effect. To attain this goal, doxorubicin (Dox) as an effective anticancer drug was loaded into poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) to improve the drug performance and also maximize the release period. After the synthesis process, the freshly made PLGA NPs with two different lactide-to-glycolide ratios (75:25 and 50:50) were evaluated physically and chemically. To determine the encapsulation efficiency, a centrifugation method was applied. Also, the drug loading effect on particle size, polydispersity index, and zeta potential was examined. The results indicated that the NPs had nearly the same diameters around 360 nm, and the entrapment efficiencies for 75:25 PLGA and 50:50 PLGA were reported around 39 and 48 %, respectively. A slight increase in all parameters was observed due to the increase of the drug loading content. The primary release was 7.91 % (w/w) and 14.70 % (w/w) for 75:25 and 50:50 drug-loaded NPs, respectively; no burst effect was observed. After 20 days, the drug release was around 70.98 and 62.22 % of the total entrapped drug for 75:25 and 50:50 drug-loaded NPs, respectively. Finally, it was found that Dox was an appropriate anticancer agent with good capability to be encapsulated in polymeric NPs and could be released from the carriers with no burst effect and favor rate.
Subject(s)
Antineoplastic Agents/pharmacology , Delayed-Action Preparations/chemistry , Doxorubicin/pharmacokinetics , Drug Delivery Systems/methods , Lactic Acid/chemistry , Polyglycolic Acid/chemistry , Antineoplastic Agents/chemistry , Cell Line, Tumor , Delayed-Action Preparations/chemical synthesis , Doxorubicin/chemistry , Drug Carriers/chemical synthesis , Drug Carriers/chemistry , Drug Delivery Systems/instrumentation , Humans , Lactic Acid/chemical synthesis , Nanoparticles/chemistry , Particle Size , Polyglycolic Acid/chemical synthesis , Polylactic Acid-Polyglycolic Acid CopolymerABSTRACT
BACKGROUND: Iodine deficiency constitutes a public health problem in many countries worldwide. Fetal neurodevelopment is affected by maternal iodine intake. The aim of present study was to assess urinary iodine excretion (UIE) in the 3 trimesters of pregnancy and evaluate its association with newborn thyroid function in Tehran, an area of iodine sufficiency. METHODS: Based on median urinary iodine in 3 trimesters, 138 pregnant women were divided into 2 groups with UIE<150 (group I) and UIE ≥ 150 µg/l (group II). Cord blood samples of their newborns were evaluated for serum concentrations of TSH, T3, T4, free T4 (FT4), and thyroglobolin. Quartiles of UIE were also determined. Correlations between mothers' UIE and newborns' thyroid function in both groups were investigated. RESULTS: Fifty-two pregnant women (38%) had median UIE<150 µg/l and 86 had (62%) UIE ≥ 150 µg/l. Median UIE in groups I and II in the 1st, 2nd, and 3rd trimesters were 125 and 212 µg/l, 97 and 213 µg/l, 93 and 227 µg/l, respectively. No significant difference was seen in thyroid function of newborns in the 2 groups. Mean concentrations of T4, T3, FT4, and TSH of newborn did not show significant difference in median UIE of mothers in various quartiles. CONCLUSION: This study shows that newborns, irrespective of mothers' UIE, in an area with a sustained iodine supplementation program, may not be at risk of alterations in thyroid functions.
