Efficacy Validation of SARS-CoV-2-Inactivation and Viral Genome Stability in Saliva by a Guanidine Hydrochloride and Surfactant-Based Virus Lysis/Transport Buffer.

To enhance biosafety and reliability in SARS-CoV-2 molecular diagnosis, virus lysis/transport buffers should inactivate the virus and preserve viral RNA under various conditions. Herein, we evaluated the SARS-CoV-2-inactivating activity of guanidine hydrochloride (GuHCl)- and surfactant (hexadecyltrimethylammonium chloride (Hexa-DTMC))-based buffer, Prep Buffer A, (Precision System Science Co., Ltd., Matsudo, Japan) and its efficacy in maintaining the stability of viral RNA at different temperatures using the traditional real-time one-step RT-PCR and geneLEAD VIII sample-to-result platform. Although Prep Buffer A successfully inactivated SARS-CoV-2 in solutions with high and low organic substance loading, there was considerable viral genome degradation at 35 °C compared with that at 4 °C. The individual roles of GuHCl and Hexa-DTMC in virus inactivation and virus genome stability at 35 °C were clarified. Hexa-DTMC alone (0.384%), but not 1.5 M GuHCl alone, exhibited considerable virucidal activity, suggesting that it was essential for potently inactivating SARS-CoV-2 using Prep Buffer A. GuHCl and Hexa-DTMC individually reduced the viral copy numbers to the same degree as Prep Buffer A. Although both components inhibited RNase activity, Hexa-DTMC, but not GuHCl, directly destroyed naked viral RNA. Our findings suggest that samples collected in Prep Buffer A should be stored at 4 °C when RT-PCR will not be performed for several days.

Intravenous Administration of Dehydroxymethylepoxyquinomicin With Polymer Enhances the Inhibition of Pancreatic Carcinoma Growth in Mice.

BACKGROUND/AIM: Pancreatic cancer, which exhibits resistance to cytotoxic and molecular targeted drugs, has an extremely poor prognosis. Nuclear factor-κB (NF-κB) is constitutively activated in many pancreatic cancer cases. Although the NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) has exhibited anti-cancer effects in pancreatic cancer models, its poor solubility limits its use to intraperitoneal administration. MATERIALS AND METHODS: Poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) forms stable polymer aggregates with DHMEQ. The stability of DHMEQ aggregated with PMB in the human blood was measured by high-performance liquid chromatography-mass spectrometry (HPLC-MS) ex vivo. Anti-pancreatic cancer effects in AsPC-1 and MIA PaCa-2 pancreatic cancer cells were evaluated by cell growth inhibition assay in vitro and tumor growth inhibition assay in vivo. RESULTS: DHMEQ aggregated with PMB (PMB-DHMEQ) remained detectable after 60 min of incubation in the human blood, whereas DHMEQ aggregated with carboxymethyl cellulose (CMC-DHMEQ) was barely detectable. PMB-DHMEQ significantly inhibited AsPC-1 and MIA PaCa-2 cell growth in vitro compared to CMC-DHMEQ. Intravenous administration of PMB-DHMEQ reduced the tumor volume and liver metastasis compared to untreated or CMC-DHMEQ-treated mice. CONCLUSION: Aggregation with PMB improved the solubility of DHMEQ, and effectively inhibited pancreatic cancer cell growth both in vitro and in vivo.

The Noninvasive Treatment for Sentinel Lymph Node Metastasis by Photodynamic Therapy Using Phospholipid Polymer as a Nanotransporter of Verteporfin.

Aim. The usefulness of photodynamic therapy (PDT) for treating sentinel lymph node (SLN) metastasis was evaluated. Materials and Methods. Verteporfin, a hydrophobic photosensitizer, forms a soluble aggregate with poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB). The concentrations of verteporfin were determined by measuring the fluorescence emitted at 700 nm. Seven days after the inoculation of A431 cells at the forearm of BALB/c nude mice, PMB-verteporfin was injected at dorsum manus and 75 J of light energy was delivered for 1 minute. Fifty-three mice were randomly assigned to the combination of PMB-verteporfin injection and light exposure, light exposure alone, PMB-verteporfin injection alone, and no treatment groups. Ten days after PDT, brachial lymph nodes, which were considered as SLNs, were harvested and evaluated. Results. The concentration of verteporfin in SLN was significantly higher than other organs. The combination of PMB-verteporfin injection and light exposure group significantly reduced the SLN metastasis (13%) comparing with no treatment group (52%), light exposure alone group (57%), and PMB-verteporfin injection alone group (46%). Conclusions. These data suggested that PDT using PMB as a nanotransporter of verteporfin could be a minimally invasive treatment of SLN metastasis in breast cancer and represent a potential alternative procedure to SLNB.