Advances in the study of peptide drugs in oral drug delivery system / 药学学报

Peptide drugs exhibit an irreplaceable role in clinics due to their high specificity, efficiency and low toxicity. At present, more than 80 peptide drugs have been approved for marketing with global sales exceeding $50 billion in 2019. However, with large molecular weights, high hydrophilicity and instability in digestive tract, oral peptide drugs encounter substantial physiological barriers leading to low oral bioavailability. Therefore, peptide drugs are mostly administered by parenteral routes. Although parenteral delivery of peptide drugs achieves high bioavailability, this is associated with inconvenience and discomfort, even causing severe side effects compared with the oral route possessing a high degree of patient compliance. Therefore, numerous studies concentrate on novel strategies to improve the oral bioavailability of peptide drugs. Some delivery technologies such as Eligen™ and Axcess™ have been successfully applied to the oral dosage form of therapeutic peptides and have accelerated relevant oral formulations for Food and Drug Administration (FDA) approval and clinical treatment. In this review, we focus on the oral peptide delivery, mainly summarizing the progress of recent strategies used to overcome oral barriers and the commercialization applications of related patents, which could facilitate the research and development (R&D) of clinical applications of oral delivery techniques for peptide drugs.

Development of Novel Microsatellite Markers and Characteristic Analysis for Sinowilsonia henryi / 中国实验方剂学杂志

Objective: To analyze the microsatellite characteristics and develop microsatellite markers for Sinowilsonia henryi, a rare and endangered plant endemic to China.Method: The Illumina second generation sequencing technology was used to establish the genome library and the microsatellite library of S. henryi. The compositions of the microsatellite were analyzed,and the primers of S. henryi were designed. Its polymorphism was analyzed by the amplification and detection of 5 S. henryi populations.Result: A total of 38,942,and 660 matched sequences of 100 bp were returned by the second generation sequencing. Among them,200,386 splice sequences were obtained by mass pruning and splicing; the number of sequences with length greater than 335 bp was 7 614, and 694 microsatellite loci were detected in the 7 614 sequences,in which the single nucleotide repeats were most and the number of A/T repeated in the single nucleotide repeats was highest. Dinucleotide showed the greatest length variation; the number of AG/CT repeats was highest, and the variation in repeat length was positively correlated with microsatellite abundance. The primers were designed for 36 S. henryi microsatellite sequences with high repetition. By PCR amplification and polyacrylamide gel electrophoresis,20 pairs of primers showed rich polymorphism and clear bands. The number of alleles (NA) ranged from 3 to 6,with average of 4;the polymorphism information content (PIC) ranged from 0.535 5 to 0.754 0,with average of 0.615 5.The population genetic analysis of 5 S. henryi populations showed that the genetic diversity of the species was high (h=0.697 5,I=1.436 8,HE=0.702 2),and the population genetic differentiation was significant (Fst=0.374).Conclusion: The population genetic analysis of S. henryi also showed that the primers developed by this study had a high usability. In this study,the primers of microsatellite markers of S. henryi were established,laying the foundation for the molecular genetics of S. henryi.

Construction of COL1A1 short hairpin RNA vector and its effect on cell proliferation and migration of gastric cancer cells / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To construct COL1A1-targeted short hairpin RNA (shRNA) vector with pSilencer 4.1-CMV neo siRNA expression vector and to evaluate its effect on proliferation and migration of gastric cancer BGC-823 cells in vitro.</p><p><b>METHODS</b>Three COL1A1-shRNA plasmids (COL1A1-shRNA-1, COL1A1-shRNA-2, COL1A1-shRNA-3), targeting different sites of COL1A1 gene, were constructed using pSilencer 4.1-CMV neo siRNA expression vector and transfected into gastric cancer BGC-823 cells. Real time quantitative RT-PCR and Western blot were performed to detect expression levels of COL1A1. MTT and Transwell migration assays were employed to evaluate the effects of COL1A1 gene silence on cell proliferation and migration.</p><p><b>RESULT</b>Three recombinant plasmids targeting COL1A1 were constructed successfully. The expressions of COL1A1 in BGC-823 cells, including mRNA and protein levels, were significantly inhibited by the COL1A1-shRNA transfectants, which resulted in a clear reduction of cell proliferation and migration capacity.</p><p><b>CONCLUSION</b>The COL1A1-shRNA can effectively knock down gene expression and inhibit proliferation and migration of gastric cancer BGC-823 cells.</p>

The experimental study of genetic engineering human neural stem cells mediated by lentivirus to express multigene / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To explore the feasibility to construct genetic engineering human neural stem cells (hNSCs) mediated by lentivirus to express multigene in order to provide a graft source for further studies of spinal cord injury (SCI).</p><p><b>METHODS</b>Human neural stem cells from the brain cortex of human abortus were isolated and cultured, then gene was modified by lentivirus to express both green fluorescence protein (GFP) and rat neurotrophin-3 (NT-3); the transgenic expression was detected by the methods of fluorescence microscope, dorsal root ganglion of fetal rats and slot blot.</p><p><b>RESULTS</b>Genetic engineering hNSCs were successfully constructed. All of the genetic engineering hNSCs which expressed bright green fluorescence were observed under the fluorescence microscope. The conditioned medium of transgenic hNSCs could induce neurite flourishing outgrowth from dorsal root ganglion (DRG). The genetic engineering hNSCs expressed high level NT-3 which could be detected by using slot blot.</p><p><b>CONCLUSIONS</b>Genetic engineering hNSCs mediated by lentivirus can be constructed to express multigene successfully.</p>

Genetic engineering neural stem cell modified by lentivirus for repair of spinal cord injury in rats / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To explore the feasibility for therapy of spinal cord injury (SCI) by genetic engineering neural stem cell (NSC) modified by lentiviral vector.</p><p><b>METHODS</b>Following the construction of the genetic engineering NSC modified by lentivirus to secrete both neurotrophic factor-3 (NT-3) and green fluorescence protein (GFP), hemisection of spinal cord at the level of T10 was performed in 56 adult Wistar rats that were randomly divided into 4 groups (n = 14), namely 3 therapeutic groups and 1 control group. The therapeutic groups were dealed with NSC, genetic engineering NSC, and concentrated lentiviral supernatant which carries both GFP and NT-3, respectively. Then used fluorescence microscope to detect the transgenic expression in vitro and in vivo, migration of the grafted cells in vivo, and used the Basso, Beattie, and Bresnahan (BBB) open-field locomotor test to assess the recovery of function.</p><p><b>RESULTS</b>The transplanted cells could survive for long time in vivo and migrate for long distance. The stable transgenic expression could be detected in vivo. The hindlimb function of the injured rats in 3 therapeutic groups, especially those dealed with genetic engineering NSC, improved obviously.</p><p><b>CONCLUSION</b>It is feasible to combine NSC with lentivirus for the repair of SCI. NSC modified by lentivirus to deliver NT-3, acting as a source of neurotrophic factors and function cell in vivo, has the potential to participate in spinal cord repair.</p>

Identification of seven plants of Gynostemma Bl.by ISSR-PCR / 中草药

Objective To identify seven species of Gynostemma BI.,including G.pentaphyllum,G. pentagynum,G.cardiospermum,G.longipes,G.yixingense,G.laxiflorum,and G.guangxiense,by in- ter-simple sequence repeat(ISSR)markers.Methods General DNA was isolated from leaves of the seven species in Gynostemma B1.by CTAB,57 primers constituted by ISSR were tested for PCR and sepharose electrophoresis.Results Fourteen primers amplified polymorphic bands,the amplification patterns of primers UBC-873 and UBC-895 were higher in terms of polymorphic and amplified band ratio.They are used to distinguish all the examined seven species.Conclusion ISSR-PCR Method provides a quick,reli- able molecular marker technique for the identification of different species of Gynostemma B1.