Hydrocarbon generation and potential of marine source rocks in supercritical water

Water, in ultra-deep layers of the earth and in layers receiving abnormally high heat, can exist in a supercritical state. Supercritical water (SCW) can participate in the transformations of organic compounds not only as a solvent but also as a reactant, influencing petroleum formation and the evolution of sedimentary organic matter. Here, we carried out hydrous pyrolysis experiments in both SCW and water vapor (WV) using two organic-rich marine rocks under closed conditions, to quantitatively evaluate the generation potential of hydrocarbons in a supercritical state and to clarify the effect of water phase on hydrous pyrolysis experiments. The results showed that SCW promoted gaseous and liquid hydrocarbon generation and facilitated the cracking of aliphatic hydrocarbons. For gaseous hydrocarbons, the action of SCW became stronger as the temperature increased. For liquid hydrocarbons, the peak yields of bitumen were enhanced by the SCW, and the temperature corresponding to peak yield in SCW was lower than that in WV. These results were attributed to the supply of hydrogen and oxygen from SCW for the petroleum formation and cracking. The δ13C and δD values of gases were also influenced by SCW. However, these values obtained in SCW did not always become positive as their yields increased. Generally, methane (CH4) was enriched in 12C and 1H. The influence of SCW on the isotopic fractionation of ethane (C2H6) and propane (C3H8) was more complex. The water phase is an important factor affecting the experimental results of hydrous pyrolysis. From these findings, it can be concluded that SCW allowed for increased conversion of sedimentary organic matter to gaseous and liquid hydrocarbons in ultra-deep layers and layers affected by volcanic-hydrothermal activity

Extranodal natural killer/T-cell lymphoma with tonsil involvement: a case report

Abstract Background Extranodal natural killer/T-cell lymphoma (ENKTL) with tonsil involvement is not common, especially in children. Case presentation A 13-year-old girl presented with an unexplained sore throat for more than 2 months, together with intermittent fever and suppurative tonsilitis. Nasopharyngoscopy revealed a pharyngeal mass. Enhanced computed tomography (CT) scan showed tonsillar hypertrophy and punctate calcification. Chronic pyogenic granulomatous inflammation with pseudoepithelial squamous epithelial hyperplasia was observed in left tonsil, and pyogenic granulomatous inflammation and a small number of T-lymphoid cells were detected in the right tonsil. The immunohistochemical results showed CD2+, CD3+, CD4+, CD5+, CD8+, granzyme B+, and TIA-1+. The Ki-67 proliferation index was 20%. The case showed T cell receptor gene rearrangement. Finally, the case was diagnosed as ENKTL of stage II with tonsil involvement. The patient received 6 cycles of chemotherapy with SMILE regimen, and showed complete response with no recurrence in the follow-up. Conclusion We presented a rare case of ENKTL with tonsil involvement in a child. The patient showed complete response to the SMILE chemotherapy with no recurrence

Enzymatic PEGylated Poly(lactone-<i>co</i>-β-amino ester) Nanoparticles as Biodegradable, Biocompatible and Stable Vectors for Gene Delivery

We have developed new, efficient gene delivery systems based on PEGylated poly­(lactone-<i>co</i>-β-amino ester) block copolymers that are biodegradable, stable and low in toxicity. The PEG–poly­[PDL-<i>co</i>-3-(4-(methylene)­piperidin-1-yl)­propanoate] (PEG–PPM) diblock and PPM–PEG–PPM triblock copolymers with various compositions were synthesized in one step via lipase-catalyzed copolymerization of ω-pentadecalactone (PDL) and ethyl 3-(4-(hydroxymethyl)­piperidin-1-yl)­propanoate (EHMPP) with an appropriate PEG (MeO–PEG–OH or HO–PEG–OH). The amphiphilic block copolymers are capable of condensing DNA in aqueous medium via a self-assembly process to form polyplex micelle nanoparticles with desirable particle sizes (70–140 nm). These micelles possess low CMC values and are stable in the medium containing serum protein molecules (FBS). Among the PEG–PPM and PPM–PEG–PPM micelles, the PEG–PPM–15% PDL micelle particles exhibited high DNA-binding ability, the fastest cellular uptake rate and highest gene transfection efficacy. Flow cytometry analysis shows that LucDNA/PEG–PPM–15% PDL polyplex micelles can effectively escape from endosomal degradation after cellular uptake likely due to the presence of the tertiary amine groups in the copolymer chains that act as proton sponges. <i>In vitro</i> cytotoxicity and hemolysis assay experiments indicate that all copolymer samples are nonhemolytic and have minimal toxicity toward COS-7 cells within the polymer concentration range (≤200 μg/mL) used for the gene transfection. These results demonstrate that the PEGylated poly­(lactone-<i>co</i>-β-amino ester) block copolymers are promising new vectors for gene delivery applications

Targeted Ultrasound-Triggered Phase Transition Nanodroplets for Her2-Overexpressing Breast Cancer Diagnosis and Gene Transfection

For successful gene therapy, it is imperative to accumulate therapeutic gene in tumor tissues followed by efficiently delivering gene into targeted cells. Ultrasound irradiation, as a noninvasive and cost-effective external stimulus, has been proved to be one of the most potential external-stimulating gene delivery strategies recently in further improving gene transfection. In this study, we developed tumor-targeting ultrasound-triggered phase-transition nanodroplets AHNP-PFP-TNDs comprising a perfluorinated poly­(amino acid) C₁₁F₁₇–PAsp (DET) as a core for simultaneously loading perfluoropentane (PFP) and nucleic acids, and a polyanionic polymer PGA-<i>g</i>-PEG-AHNP as the shell for not only modifying the surface of nanodroplets but also introducing an anti-Her2/<i>neu</i> peptide (AHNP) aiming to targeted treatment of Her2-overexpressing breast cancer. The results showed the average diameter of AHNP-PFP-TNDs was below 400 nm, nearly spherical in shape. The modification of PGA-<i>g</i>-PEG-AHNP not only increased the serum stability of the nanodroplets but also improved the affinity between nanodroplets and Her2-overexpressing breast cells. Both intratumor and intravenous injection of AHNP-PFP-TNDs into nude mice bearing HGC-27 xenografts showed that the gene transfection efficiency and the ultrasound contrast effect were significantly enhanced after exposed to the ultrasound irradiation with optimized ultrasound parameters. Therefore, this targeting nanodroplets system could be served as a potential theranostic vector for tumor targeting ultrasound diagnosis and gene therapy

Enzymatic PEG-Poly(amine-<i>co</i>-disulfide ester) Nanoparticles as pH- and Redox-Responsive Drug Nanocarriers for Efficient Antitumor Treatment

We have designed and constructed novel multifunctional nanoparticle drug-delivery systems that are stable under physiological conditions and responsive to tumor-relevant pH and intracellular reduction potential. The nanoparticles were fabricated from enzymatically synthesized poly­(ethylene glycol) (PEG)-poly­(ω-pentadecalactone-<i>co</i>-<i>N</i>-methyldiethyleneamine-<i>co</i>-3,3′-dithiodipropionate) (PEG-PPMD) and PEG-poly­(ε-caprolactone-<i>co</i>-<i>N</i>-methyldiethyleneamine-<i>co</i>-3,3′-dithiodipropionate) (PEG-PCMD) block copolymers via self-assembly processes in aqueous solution. At acidic pH and in the presence of a reductant (e.g., d,l-dithiothreitol or glutathione), the nanosized micelle particles rapidly swell and disintegrate due to the protonation of amino groups and reductive cleavage of disulfide bonds in the micelle cores. Consistently, docetaxel (DTX)-loaded PEG-PPMD and PEG-PCMD micelles can be triggered synergistically by acidic endosomal pH and a high intracellular reduction potential to rapidly release the drug for efficient killing of cancer cells. The drug formulations based on PEG-PPMD and PEG-PCMD copolymers exhibited a substantially higher potency than free DTX in inhibiting tumor growth in mice, whereas their therapeutic effects on important organ tissues were minimal. These results demonstrate that PEG-PPMD and PEG-PCMD nanoparticles have a great potential to serve as site-specific, controlled drug-delivery vehicles for safe and efficient antitumor treatment