OBJECTIVE： To test the in vitro antiviral activity of a crude tissue extract （CTE/from the earthworm Eisenia fetida, determine any effective components in the CTE, andelucidate possiblemechanismsofaction. METHODS： ...OBJECTIVE： To test the in vitro antiviral activity of a crude tissue extract （CTE/from the earthworm Eisenia fetida, determine any effective components in the CTE, andelucidate possiblemechanismsofaction. METHODS： A CTE was made by homogenizing earthworms, followed by treatment with ammoni- um sulfate, then thermal denaturation. Inhibition of virus-induced cytopathic effect （CPE） was used to assess antiviral activity. Chromatographic analy- sis was used to identify effective components in the CTE. RESULTS： The CTE inhibited viral CPE at non-cyto- toxic concentrations. Chromatography indicated that antiviral components corresponded to three active peaks indicative of proteases, nucleases and lysozymes. For adenoviruses, reduction in viral ac- tivity occurred for 100 lag/mL CTE. The reduction in adenoviral activity for four fractions was 100%, 91.8%, 86.9%, and 94.7%. For influenza viruses, re- duction in viral activity of 100%, 86.6%, 69.1% and 88.3% was observed for 37 pg/mL CTE. In addition, three active fractions mixture had stronger antiviral activity （98.7% and 96.7%） than three fractions alone.Gel electrophoresis results indicated that nu- cleases from E. fetida could degrade the genome of influenza viruses and adenoviruses. CONCLUSION： The earthworm CTE displayed non-specific antiviral properties, possibly mediated by a combination of proteases, nucleases and lyso- zymes. Nucleases likely participate in the antiviral process, and degrade the genome of the virus thereby preventing further replication.展开更多
The cytotoxicity and non-specific cellular uptake of the most popular composition of upconversion nanoparticle （UCNP）, NaYF4：Yb^3＋：Er^3＋, is reported using normal human skin cells, including dermal fibroblasts a...The cytotoxicity and non-specific cellular uptake of the most popular composition of upconversion nanoparticle （UCNP）, NaYF4：Yb^3＋：Er^3＋, is reported using normal human skin cells, including dermal fibroblasts and immortalized human epidermal linear keratinocytes （HaCaT）. A new hydrophilization reaction of as-synthesized UCNPs based on tetramethylammonium hydroxide （TMAH） enabled evaluation of the intrinsic cytotoxicity of bare UCNPs. The cytotoxicity effects of the UCNP surface-coating and polystyrene host were investigated over the concentration range 62.5-125 μg/mL with 24-h incubation, using a MTT test and optical microscopy. The fibroblast viability was not compromised by UCNPs, whereas the viability of keratinocytes varied from 52% ± 4% to 100% ± 10% than the control group, depending on the surface modification. Bare UCNPs reduced the keratinocyte viability to 76% ± 3%, while exhibiting profound non-specific cellular uptake. Hydrophilic poly（D,L-lactide）- and poly（maleic anhydride-alt-l-octadecene）-coated UCNPs were found to be least cytotoxic among the polymer-coated UCNPs, and were readily internalized by human skin cells. Polystyrene microbeads impregnated with UCNPs remained nontoxic. Surprisingly, no correlation was found between UCNP cytotoxicity and the internalization level in cells, although the latter ranged broadly from 0.03% to 59%, benchmarked against 100% uptake level of TMAH-UCNPs.展开更多
文摘OBJECTIVE： To test the in vitro antiviral activity of a crude tissue extract （CTE/from the earthworm Eisenia fetida, determine any effective components in the CTE, andelucidate possiblemechanismsofaction. METHODS： A CTE was made by homogenizing earthworms, followed by treatment with ammoni- um sulfate, then thermal denaturation. Inhibition of virus-induced cytopathic effect （CPE） was used to assess antiviral activity. Chromatographic analy- sis was used to identify effective components in the CTE. RESULTS： The CTE inhibited viral CPE at non-cyto- toxic concentrations. Chromatography indicated that antiviral components corresponded to three active peaks indicative of proteases, nucleases and lysozymes. For adenoviruses, reduction in viral ac- tivity occurred for 100 lag/mL CTE. The reduction in adenoviral activity for four fractions was 100%, 91.8%, 86.9%, and 94.7%. For influenza viruses, re- duction in viral activity of 100%, 86.6%, 69.1% and 88.3% was observed for 37 pg/mL CTE. In addition, three active fractions mixture had stronger antiviral activity （98.7% and 96.7%） than three fractions alone.Gel electrophoresis results indicated that nu- cleases from E. fetida could degrade the genome of influenza viruses and adenoviruses. CONCLUSION： The earthworm CTE displayed non-specific antiviral properties, possibly mediated by a combination of proteases, nucleases and lyso- zymes. Nucleases likely participate in the antiviral process, and degrade the genome of the virus thereby preventing further replication.
文摘The cytotoxicity and non-specific cellular uptake of the most popular composition of upconversion nanoparticle （UCNP）, NaYF4：Yb^3＋：Er^3＋, is reported using normal human skin cells, including dermal fibroblasts and immortalized human epidermal linear keratinocytes （HaCaT）. A new hydrophilization reaction of as-synthesized UCNPs based on tetramethylammonium hydroxide （TMAH） enabled evaluation of the intrinsic cytotoxicity of bare UCNPs. The cytotoxicity effects of the UCNP surface-coating and polystyrene host were investigated over the concentration range 62.5-125 μg/mL with 24-h incubation, using a MTT test and optical microscopy. The fibroblast viability was not compromised by UCNPs, whereas the viability of keratinocytes varied from 52% ± 4% to 100% ± 10% than the control group, depending on the surface modification. Bare UCNPs reduced the keratinocyte viability to 76% ± 3%, while exhibiting profound non-specific cellular uptake. Hydrophilic poly（D,L-lactide）- and poly（maleic anhydride-alt-l-octadecene）-coated UCNPs were found to be least cytotoxic among the polymer-coated UCNPs, and were readily internalized by human skin cells. Polystyrene microbeads impregnated with UCNPs remained nontoxic. Surprisingly, no correlation was found between UCNP cytotoxicity and the internalization level in cells, although the latter ranged broadly from 0.03% to 59%, benchmarked against 100% uptake level of TMAH-UCNPs.
