Thymoquinone as an electron transfer mediator to convert Type II photosensitizers to Type I photosensitizers.

The development of Type I photosensitizers (PSs) is of great importance due to the inherent hypoxic intolerance of photodynamic therapy (PDT) in the hypoxic microenvironment. Compared to Type II PSs, Type I PSs are less reported due to the absence of a general molecular design strategy. Herein, we report that the combination of typical Type II PS and natural substrate carvacrol (CA) can significantly facilitate the Type I pathway to efficiently generate superoxide radical (O2-•). Detailed mechanism study suggests that CA is activated into thymoquinone (TQ) by local singlet oxygen generated from the PS upon light irradiation. With TQ as an efficient electron transfer mediator, it promotes the conversion of O2 to O2-• by PS via electron transfer-based Type I pathway. Notably, three classical Type II PSs are employed to demonstrate the universality of the proposed approach. The Type I PDT against S. aureus has been demonstrated under hypoxic conditions in vitro. Furthermore, this coupled photodynamic agent exhibits significant bactericidal activity with an antibacterial rate of 99.6% for the bacterial-infection female mice in the in vivo experiments. Here, we show a simple, effective, and universal method to endow traditional Type II PSs with hypoxic tolerance.

ZnO-incorporated alginate assemblies: Tunable pH-responsiveness and improved drug delivery for cancer therapy.

Delivering drugs selectively to tumor tissues is a significant challenge in cancer therapy, and pH-responsive polymeric assemblies have shown great potential in achieving this goal. In this study, we developed a pH-responsive alginate-based assemblies, called (amine-modified ZnO)-oxidized alginate-PEG ((ZnO-N)-OAl-PEG), for selective drug delivery in cancer treatment. The incorporation of ZnO-N nanoparticles into the alginate-based assemblies enables pH-responsiveness and maintains stability under physiological conditions. At an acidic pH, (ZnO-N)-OAl-PEG disassembles due to the conversion of ZnO to Zn2+, which triggers the unloading of doxorubicin (DOX) from the imine bond between DOX and alginate. This unloading results in the death of cancer cells and inhibition of tumor growth. The anticancer efficacy of (DOX/ZnO-N)-OAl-PEG was demonstrated in vitro and in vivo, providing promising prospects for cancer treatment based on ZnO-induced pH-responsiveness. These findings may also inspire the development of advanced drug delivery systems (DDSs) for cancer therapy.

[Genetic analysis of a child with D bifunctional protein deficiency born to a consanguineous pedigree].

OBJECTIVE: To explore the genetic etiology of a child with D bifunctional protein deficiency (DBPD) born to a consanguineous pedigree. METHODS: A child with DBPD who was admitted to the First Affiliated Hospital of Hainan Medical College on January 6, 2022 due to hypotonia and global developmental delay was selected as the study subject. Clinical data of her pedigree members were collected. Peripheral blood samples of the child, her parents and elder sisters were collected and subjected to whole exome sequencing. Candidate variant was validated by Sanger sequencing and bioinformatic analysis. RESULTS: The child, a 2-year-and-9-month-old female, had featured hypotonia, growth retardation, unstable head lift, and sensorineural deafness. Serum long-chain fatty acids were elevated, and auditory brainstem evoked potentials had failed to elicit V waves in both ears with 90 dBnHL stimulation. Brain MRI revealed thinning of corpus callosum and white matter hypoplasia. The child's parents were secondary cousins. Their elder daughter had a normal phenotype and no clinical symptoms related to DBPD. Elder son had frequent convulsions, hypotonia and feeding difficulties after birth, and had died one and a half month later. Genetic testing revealed that the child had harbored homozygous c.483G>T (p.Gln161His) variants of the HSD17B4 gene, for which both of her parents and elder sisters were carriers. Based on the guidelines from the American College of Medical Genetics and Genomics, the c.483G>T (p.Gln161His) was rated as a pathogenic variant (PM1+PM2_Supporting+PP1+PP3+PP4). CONCLUSION: The homozygous c.483G>T (p.Gln161His) variants of the HSD17B4 gene caused by the consanguineous marriage probably underlay the DBPD in this child.

Fabrication of hyaluronic acid-based micelles with glutathione-responsiveness for targeted anticancer drug delivery.

Hyaluronic acid (HA), a natural polymer, has gained much attention recently because of its good biocompatibility and extensive availability. Herein, a novel drug delivery system based on hyaluronic acid-tetraphenyl ethylene conjugate (HA-SS-TPE) with glutathione (GSH)-responsiveness for targeted drug delivery is designed. During the self-assembly of HA-SS-TPE, doxorubicin (DOX) is loaded to form DOX-loaded polymeric micelles. These as-prepared DOX-loaded polymeric micelles not only exhibit fluorescent emission, but also fast glutathione-triggered dissociation to unload DOX by responding to tumor microenvironments. In-vitro investigations showed that the DOX-loaded polymeric micelles presented a higher intracellular release ratio in CD44-positive cells (ES2 and Hela) than in CD44-negative cells (MCF-7 and L929). Notably, in vivo investigations showed that DOX@HA-SS-TPE significantly suppressed tumor growth. As a result, such a GSH-responsive drug delivery system with fluorescent feature provides a potential treatment for CD44-overexpressing cancers.

Use of pH-Active Catechol-Bearing Polymeric Nanogels with Glutathione-Responsive Dissociation to Codeliver Bortezomib and Doxorubicin for the Synergistic Therapy of Cancer.

Synergistic therapy holds promising potential in cancer treatment. Here, the inclusion of catechol moieties, a disulfide cross-linked structure, and pendent carboxyl into the network of polymeric nanogels with glutathione (GSH)-responsive dissociation and pH-sensitive release is first disclosed for the codelivery of doxorubicin (DOX) and bortezomib (BTZ) in synergistic cancer therapy. The pendent carboxyl groups and catechol moieties are exploited to absorb DOX through electrostatic interaction and conjugate BTZ through boronate ester, respectively. Both electrostatic interactions and boronate ester are stable at neutral or alkaline pH, while they are instable in an acidic environment to further recover the activities of BTZ and DOX. The polymeric nanogels possess a superior stability to prevent the premature leakage of drugs in a physiological environment, while their structure is destroyed in response to a typical endogenous stimulus (GSH) to unload drugs. The dissociation of the drug-loaded nanogels accelerates the intracellular release of DOX and BTZ and further enhances the therapeutic efficacy. In vitro and in vivo investigations revealed that the dual-drug loaded polymeric nanogels exhibited a strong ability to suppress tumor growth. This study thus proposes a new perspective on the production of multifunctional polymeric nanogels through the introduction of different functional monomers.

Clinical Efficacy of the Preservation of the Hepatic Branch of the Vagus Nerve on Delayed Gastric Emptying After Laparoscopic Pancreaticoduodenectomy.

BACKGROUND: Delayed gastric emptying (DGE) is a common complication following laparoscopic pancreaticoduodenectomy (LPD), although it remains incompletely understood, and only few studies have investigated the clinical benefits of hepatic branch of the vagus nerve (HBVN) preservation on DGE after LPD until now. We intended to evaluate the effect of preservation of the HBVN during LPD on the incidence of DGE. METHODS: A total of 274 consecutive LPDs performed at a single center between July 2014 and December 2019 with available videos were retrospectively reviewed. DGE was defined according to the International Study Group of Pancreatic Surgery (ISGPS) criteria, and HBVN condition during the LPD procedure was evaluated through a video review. Risk factors associated with DGE were assessed by performing univariate and multivariate logistic regression analyses. Postoperative outcomes between the HBVN-preserved and HBVN-injury groups were compared before and after propensity score matching (PSM). RESULTS: One hundred fifty-six (56.93%) patients underwent LPD with HBVN-preserved and 118 (43.07%) with HBVN injury. DGE occurred in 33.2% of patients (n = 91) with grades B and C occurring at 13.9% (n = 38) and 7.7% (n = 21), respectively. Longer operative time, more EIBL, HBVN injury, POPF (grades B and C), postoperative hemorrhage, intra-abdominal infection, and Clavien-Dindo ≥III were identified as risk factors for DGE in the univariate analysis. Then, in the multivariate analysis, HBVN injury and intra-abdominal infection were found to be independent risk factors affecting the incidence of DGE (any grade) or clinically relevant DGE (grades B and C). Furthermore, the prevalence of DGE was significantly higher in the HBVN-injury group than in the HBVN-preserved group before and after PSM analysis (46.61% vs. 23.08%, P<0.001; 42.59% vs. 23.15%, P=0.013). CONCLUSIONS: HBVN preservation during LPD might be associated with a reduced incidence of DGE as a framework for prospective quality improvement.

Optimized mesoporous silica nanoparticle-based drug delivery system with removable manganese oxide gatekeeper for controlled delivery of doxorubicin.

Rapid progress has been made for mesoporous silica nanoparticle (MSN) in recent years; however, efforts to fabricate MSN with adjustable size have been met with limited advancement in drug delivery, especially for the synthesis of MSN with adjustable size in the range of 150-300 nm. Herein we report the construction of a series of MSNs with adjustable specific surface area, size, and pore structure, depending on the different silicon monomers selected. The optimized MSN showed large specific surface area and appropriate size distribution for efficiently anchoring doxorubicin (DOX) through the imine linkage formed. Based on the remarkable features of the unique MSN, a novel MSN-based drug delivery system was prepared through the introduction of polydopamine/manganese oxide (PDA/MnO2) coating, which reduced the premature leakage of drugs in physiological environments, and yet facilitated drug release when destroyed by responding to endogenous glutathione (GSH) at the tumor sites. Notably, the transformation of MnO2 to Mn2+ resulted in the collapse of the PDA/MnO2 coating, which facilitated drug release and therefore indicated the controlled release feature. It was demonstrated that the drug-loaded MSN-based drug delivery system delivered drugs into cancer cells and showed effective inhibition against cancer cell growth. These results suggested that the emergence of MSN with adjustable size can expand the application of MSN in drug delivery.

Regulatory B cells induced by pancreatic cancer cell-derived interleukin-18 promote immune tolerance via the PD-1/PD-L1 pathway.

Dysregulation of regulatory B cells (Bregs), a type of immunosuppressive lymphocyte, are associated with development of autoimmune diseases and cancers. Bregs produce immune tolerance-inducing cell surface molecules and tolerogenic cytokines (interleukin [IL]-10 and transforming growth factor-beta). We previously showed that levels of the inflammatory cytokine IL-18 were increased in patients with pancreatic cancer. In the present study study, we found that pancreatic cancer cell-derived IL-18 increases Breg-induced immunosuppression. IL-18 also promoted B-cell proliferation and IL-10 expression in vivo and in vitro. In addition, IL-18 upregulated membrane PD-1 in B cells and inhibited the antibody-dependent cellular cytotoxicity of Tc cells and natural killer cells. Finally, the combination of a natural IL-18 inhibitor (IL-18BP) and a PD-1/PD-L1 inhibitor suppressed tumor growth and metastasis in a murine pancreatic cancer model. Our results show that IL-18 and PD-1/PD-L1 could be therapeutic targets in pancreatic cancer.

[Characteristics of 4-chlorophenol degradation by a soil bacterium Acinetobacter sp].

The bacterium capable of degrading 4-chlorophenol (4-CP) was enriched and isolated from agricultural soil. It was gram-negative, rod-shaped bacterium, and identified as Acinetobacter sp. based on the analysis of the 16S rRNA gene fragment. It was able to utilize 4-CP as a sole carbon source. The degradation mechanism of 4-CP by this isolate was proposed as a modified ortho-cleavage pathway, the activity of chlorocatechol 1,2-dioxygenase was markedly induced. The bacterial isolate grew well and exhibited a high degradation efficiency when the initial concentration of 4-CP was between 2-8 mmol/L. It was able to survive in the presence of 4-CP at higher concentrations (up to 8 mmol/L). Not only 4-CP, but also 2-chlorophenol, 3-chlorophenol, phenol, and 2,4-dichlorophenol, were also growth substrates for the isolate. The results of co-substrate supplementation illustrated the suitable conditions of the isolate to improve growth rate and 4-chlorophenol biodegradation efficiency. The results suggested that the isolate had a potential use for bioremediation of the site contaminated with 4-chlorophenol.

Effect of salinity variations on the performance of activated sludge system.

OBJECTIVE: To investigate the influence of salinity variations on the performance of activated sludge systems, treating domestic wastewater. METHODS: The completely mixed reactor was used and operated in a batch-wise mode. The activated sludge taken from the Gaobeidian Wastewater Treatment Plant was used as a seeding sludge. Total organic carbon (TOC), oxygen uptake rate (OUR) and suspended solids (SS) were used as parameters to characterize the performance of the treatment systems. TOC was measured using a TOC-analyzer (TOC-5000, Japan). The OUR value was measured with a dissolved oxygen meter (YSI model-58). SS was measured gravimetrically. RESULTS: The TOC removal efficiency and the OUR value of activated sludge were not deteriorated when the NaCl shock concentration was less than 0.5 g/L. However, when the NaCl shock concentrations were up to 10g/L and 20 g/L, the OUR of activated sludge was reduced by 35% and TOC removal efficiency was dropped by 30%, compared with the control experiment without NaCl shock loading. CONCLUSION: The effect of NaCl shock loading on the activated sludge wastewater treatment system is dependant upon the NaCl concentrations and the degree of influence can be inferred through the change of substrate utilization rate at different shock NaCl loadings.