Thermal-sensitive hydrogels as nasal vaccine delivery systems.

The National Key Laboratory of Biochemical Engineering established in 1995 is affiliated with the Institute of Process Engineering, Chinese Academy of Sciences (CAS), and located in Zhong-guan-cun (Beijing, China). The National Key Laboratory of Biochemical Engineering is working towards developments in the fields of bio-reaction, bioseparation and bio-formulation, by chemical and material methods. Over the last 5 years, approximately 200 scientists and students have worked at the laboratory, and published over 400 articles. Numerous universities, companies and institutes have established cooperative relationships with this laboratory, and over 70 cooperative research programs with other researchers have been conducted in the past few years.

Development of oocytes from synchronized follicles of early prepubertal goats under exotic hormone control.

The aim of this study was to establish whether early prepubertal Sannen dairy goat could provide a large source of ova for SCNT. The effects of different hormonal treatments including untreated control, FSH alone, estadiol plus progesterone (E2-P4), and E2-P4 and FSH (E2-P4-FSH) on ovary size, follicle number and size were studied using the early prepubertal goats aged 39-60 days. Then prepubertal goats aged 39-120 days were categorized into three groups to study the effect of age on recruited follicle number. The meiotic competence of oocytes derived from > or =3 mm follicles recovered from the early prepubertal goats treated with E2-P4-FSH was compared with those treated with FSH alone. Finally, the development competence of the ova from the early goats treated with E2-P4-FSH was evaluated by SCNT. The E2-P4-FSH treatment produced the largest ovaries, the highest numbers of total follicles and follicles > or =3 mm diameter compared with the other treatments. The number of > or =3 mm follicles per goat treated with E2-P4-FSH was significantly higher for those in the age groups 39-60 days than those in the age groups 61-90 days and 91-120 days. The FSH alone treatment resulted in a lower proportion matured ova in vitro within 27 hr than from those goats treated with E2-P4-FSH. Ova derived from the early prepubetal goats resulted in lower rate of blastocyst in SCNT (15.3% versus 22.1%, P < 0.01) than that of adult goat However, the number of ova recovered per goat was substantially greater for the prepubertal goats (108 +/- 10.3 Versus 28 +/- 5.0). Consequently, the younger goats produced significantly more blastocyst (7.1 +/- 2.7 versus 4.2 +/- 1.4) per head. It was concluded that early pubertal goats treated with E2-P4-FSH could provide a relatively high number of developmentally competent ova for SCNT studies.

Secondary SCNT doubles the pre-implantation development rate of reconstructed interspecies embryos by using cytoplasts of Sannen dairy goat ova.

The aim of this study was to investigate whether ova of Sannen goat could support the pre-implantation development of interspecies embryos constructed through somatic cell nucleus transfer (SCNT) embryos and whether secondary SCNT (SSCNT) could improve the pre-implantation development of those embryos. The primary SCNT (PSCNT) embryos were produced by using Sannen goat ovum cytoplasts as recipients and fibroblast cells, derived from human, rabbit and Boer goat skins, as nucleus donors. The blastomeres of 8 to 16 cells stage of PSCNT embryos were subsequently used as nucleus donor cells and Sannen goat ovum cytoplasts as recipients to evaluate the effect of SSCNT on the pre-implantation development rate of these reconstructed interspecies embryos. Our results indicate that the pre-implantation development rates of SSCNT embryos reconstructed using these three different blastomeres are almost twice of that of corresponding PSCNT embryos (human, 15.8% vs. 7.8%; rabbit, 27.9% vs. 12.5%; Boer goat 55.3% vs. 24.5%; P < 0.05 in all three cases). The time durations that embryos need for the serial events of remodeling and reprogramming to take place vary, depending on the animal species of nucleus donors. These data suggest that remodeling and reprogramming of donor nucleus may be enhanced by prolonged exposure of donor nucleus to maternal cytoplast. We conclude that Sannen goat cytoplast can support the pre-implantation development of embryos constructed with nuclei from various donors, including fibroblasts of human, rabbit and Boer goat; and the somatic nucleus derived from different species requires more time to achieve its reprogramming necessary for pre-implantation development.