Research progress of poly (β-amino ester)s-based gene vector / 药学学报

Poly (β-amino ester)s (PβAEs) contain tertiary amine backbones and biodegradable ester bonds, making them highly biocompatible and pH-responsive. Meanwhile, originated from combinatorial libraries, PβAEs are simple to synthesize, easy to obtain raw materials and can be easily adapted to meet the different performance needs of gene carriers by adjusting the monomer type, monomer ratio and reaction time. Therefore, PβAEs are promising material for non-viral gene carriers. This paper provides a comprehensive overview of the properties and synthesis of PβAEs gene carriers and summarizes the progress of research on the gene delivery of each type of PβAEs.

Survey on host animal and molecular epidemiology of hantavirus in Chuxiong prefecture, Yunnan province / 中华流行病学杂志

Objective To determine the hosts of hantavirus (HV) and its molecular epidemiological characteristics, to provide evidence for prevention and control on hemorrhagic fever with renal syndrome (HFRS). Methods Rodents were captured by a special trap within the residential area. The antigens of HV in lung tissues were detected by direct immuno-fluorescence assay (DFA). Nucleotide sequences of HV were amplified by RT-PCR with HV genotype-specific primer. The amplified genes were then sequenced. Phylogenetic tree were built on nucleotide sequence with Clusta1X 1.83 software. Results 1421 rodents were captured and classified into 8 species of 4 Genera in the epidemic area within 10 counties of Chuxiong prefecture, Yunnan province, between 2005 and 2006. Out of the 1421 rodents, 1056 (74.31%) of them were Rattus norvegicas and 280 (19.70%) belonged to Rattus flavipectus. The antigens of HV were detected by DFA in lung tissues and the total positive rate of HV was 5.15% (53/ 1029). After applying the sequencing nucleotide method to the 53 positive specimens, data showed that 21 specimens were positive and all of them belonged to Seoul type ( 15 samples were from Rattus norvegicus, 4 samples Rattasflavipectas, 2 samples Rattus nitidas). The partial S segments from 12 specimens were sequenced which appeared homologic with R22, L99 and HLD65 from GenBank in relatively high level (87.1%-99.7%). When compared to 76-118 strain of Hantaan type, their homologic degree was only 64.4%-69.1%. Results from Phylogenetic analysis showed that 12 specimens belonged to Seoul type. As for their homology, they were significantly similar to Seoul type and could be tentatively divided into two subtypes S1 and S3. Conclusion It was confirmed that the Seoul type virus, as HFRS' s pathogenetic agent mainly carried by rats, prevailed widely in Chuxiong prefecture. Owing to the local ecological environment, we also noticed the characteristics of different HV subtypes among Seoul type.