[Study on effect of sho-saiko-to compound on growth of nasopharyngeal carcinoma cells in CNE-bearing nude mice].

OBJECTIVE: To investigate the role of sho-saiko-to compound (SSTC) on the growth of the well-differentiated squamous cell line 1 of nasopharyngeal carcinoma (CNE-1) and well-differentiated CNE-2 in tumor-bearing nude mouse, and try to supply scientific data for its clinical development. METHOD: SSTC were prepared by concentration gradients, and the effect of SSTC on the growth and proliferation of the CNE-1 and CNE-2 were investigated by MT assay and soft-agar colony formation test. After setting up the subcutaneous tumor-bearing nude mouse model at the right lower back (0.2 mL CNE-2 cell suspension, 5 x 10(5)/mL), we randomly divided forty mice into 5 groups and gave high, middle and low concentration groups of SSTC (0.5, 0.25, 0.125 g X mL(-1) by intragastric administration. Positive and negative groups were set up for comparison. After constant administration for 15 days, the volume and weight of the tumor were measured for inhibition rate, so as to investigate the role of SSTC on the CNE-2 bearing tumor. RESULT: In vitro, compared with negative control, SSTC at different gradient concentrations were cultured with the CNE-1 and CNE-2 for 24 h, 48 h and 72 h. It showed that the growth and proliferation of both cell lines were inhibited to some extent. The inhibition rate was increased as the concentration and culture time increasing. Both MTT assay and soft-agar colony formation test showed that the 50% inhibiting concentration (IC50) was about 2.5 g X L(-1). In vivo, compared with negative control, the SSTC could slow down the tumor growth in the SSTC treated groups. The tumor growth of the negative control group (0.76 +/- 0.28) g, (962.88 +/- 245.96) mm3 and the low concentration group of SSTC (0.88 +/- 0.40) g, (1239.66 +/- 421.93) mm3 were obviously faster than those of the high, middle concentration group of SSTC (0.22 +/- 0.14) g, (239.31 +/- 137.07) mm3; (0.20 +/- 0.16) g, (263.42 +/- 166.57) mm3 and CTX positive control group (0.20 +/- 0.10) g, (246.72 +/- 194.6) mm3 (P<0.05). CONCLUSION: SSTC could efficiently inhibit the growth and proliferation of CNE-1 and CNE-2 in vitro, and slow down the tumor growth of the CNE-2 bearing nude mice. It may be a new compound of Chinese medicine for nasopharyngeal carcinoma therapy.

A femtosecond transient absorption study of charge photogeneration and recombination dynamics in photovoltaic polymers with different side-chain linkages.

A pair of 9-arylidene-9H-fluorene and benzothiadiazole based, low-bandgap copolymers differing merely in the para or meta substitution of alkoxy groups to the arylidene linkages, i.e. p-PAFDTBT and m-PAFDTBT respectively, were comparatively investigated by using morphological characterization, ultrafast spectroscopy and quantum chemical calculations. Despite the subtle difference in the alkoxy substitution patterns, p-PAFDTBT molecules in photoactive films were shown to have a higher degree of crystallinity owing to the relatively less rotational torsion of the arylidene linkages. As a result, in either neat or fullerene-blended films, p-PAFDTBT compared to m-PAFDTBT gave rise to a substantially higher charge yield and much slower charge recombination. This work demonstrates that the alkoxy substitution pattern and the arylidene linkage are highly influencing on the morphology of the photoactive layers and thereby on the photovoltaic performance of the semiconducting copolymers.