Effects of polycaprolactone degradation products on the water flea, Daphnia magna: Carbodiimide additives have acute and chronic toxicity.

Plastics have benefited our lives in many ways, but their long persistence in the environment causes serious problems. Rapid decomposition and detoxification of plastics after use are significant challenges. As a possible solution, biodegradable plastics have attracted attention, and for environmental risk assessment research on polymer toxicity, use of indicator organisms, like water fleas and fish, has increased globally. However, such research often focuses on standardized substances without considering changes in toxicity due to plastic degradation products. Additionally, tests generally focus on acute toxicity, while long-term effects on organismal reproduction and lifespan are largely unknown. Understanding the impact of degraded polymers on biological activities is crucial for accurate risk assessment. In this study, we investigated the biological toxicity of substances generated during degradation of polycaprolactone (PCL), a common biodegradable plastic, using the indicator organism, Daphnia magna. We examined PCL, oligocaprolactones (OCLs), and monomers resulting from polymer cleavage, as well as carbodiimides, added during polyester synthesis. As a result, PCL, which is insoluble in water, reduced individual survival and total number of offspring at an exposure concentration of 100 mg/L, while no toxicity was observed for water-soluble degradation products, OCLs, and monomers. Furthermore, carbodiimides, which are expected to be released during PCL degradation, showed strong toxicity, significantly reducing individual survival and total number of offspring at 0.1-10 mg/L. These findings suggest that changes in physical properties due to polymer degradation and release of additives can significantly alter their toxicity.

EFFICACY AND SAFETY OF A DEXAMETHASONE-BASED MOUTHWASH TO PREVENT CHEMOTHERAPY-INDUCED STOMATITIS IN WOMEN WITH BREAST CANCER: A MULTICENTRE, OPEN-LABEL, RANDOMISED PHASE 2 STUDY.

PURPOSE: No standard approach other than oral care is available for preventing chemotherapy-induced stomatitis in patients with breast cancer. In this randomized, controlled phase 2 trial, we aimed to assess the efficacy and safety of a dexamethasone-based mouthwash in preventing chemotherapy-induced stomatitis in patients with early breast cancer. BASIC PROCEDURES: Patients with breast cancer scheduled for epirubicin and cyclophosphamide (EC) or docetaxel and cyclophosphamide (TC) therapy were selected and allocated in a 1:1 ratio to the intervention and control groups. The intervention group received chemotherapy, oral care, and a dexamethasone-based mouthwash, whereas the control group received chemotherapy and oral care. The primary endpoint was the incidence of stomatitis. This was a phase 2 study, and the significance level for the analysis of the primary endpoint was set a priori at 0.2. MAIN FINDINGS: Data pertaining to 58 patients in the control group and 59 patients in the intervention group were analyzed. Stomatitis incidence was 55% and 38% in the control and intervention groups, respectively (risk ratio, 0.68; 80% confidence interval, 0.52-0.88; P = .052). Stomatitis severity was lower in the intervention group than in the control group (P = .03). The proportion of patients who adhered to the mouthwash regimen was 87% (interquartile range, 67.8%-95.3%). No severe oral infections were observed. PRINCIPAL CONCLUSIONS: The dexamethasone-based mouthwash safely reduced stomatitis incidence and severity in patients receiving chemotherapy for early breast cancer. Phase 3 clinical trials are warranted for validating our results.

Salivary Immunoglobulin A Secretion Rate During Peak Period Conditioning Regimens in Triathletes.

ABSTRACT: Matsumoto M, Satoh, K, Kushi, H, Hamuro, K, Sakurai, M, Saito, H, Tanaka, R, Saito, T, Kohda, N, and Hamada, K. Salivary immunoglobulin A secretion rate during peak period conditioning regimens in triathletes. J Strength Cond Res 35(5): 1389-1396, 2021-Triathletes often feel unwell during the conditioning period (peak period) leading up to a race. The aim of this study was to evaluate the factors relevant to the condition of athletes and their impact on mucosal immune responses and the salivary immunoglobulin A (IgA) secretion rate. This study recruited college student triathletes (33 men and 7 women) who participated in an Olympic distance race. For each subject, the salivary IgA rate was measured continuously for 1 month before the race (peak period). Data on physical activity during the peak period were calculated in metabolic equivalents, and the relationships between these factors and the salivary IgA secretion rate were evaluated. The average amount of physical activity was highest during the 2- to 3-week period before the race, at 744.7 ± 51.5 kcal expended per day. In subjects who, on average, expended more than 1,000 kcal·d-1 in physical activity between 12 and 14 days before the race, the salivary IgA secretion rate was significantly reduced compared with the value at 1 week before the race (p < 0.05). On the day before the race, a further reduction was observed (p < 0.1). The salivary IgA secretion rate was decreased by high-intensity exercise during the peak period in advance of a race; this was associated with a loss of optimal condition just before the race.

Study protocol for efficacy and safety of steroid-containing mouthwash to prevent chemotherapy-induced stomatitis in women with breast cancer: a multicentre, open-label, randomised phase 2 study.

INTRODUCTION: Stomatitis is a frequent adverse event in patients undergoing chemotherapy for breast cancer. Stomatitis can hamper oral nutrition resulting in malnutrition, reduce quality of life and introduce the need for dose reductions and interruption of chemotherapy; however, there is currently no standard approach for preventing chemotherapy-induced stomatitis. We aimed to assess the safety and efficacy of a dexamethasone-based elixir mouthwash for preventing chemotherapy-induced stomatitis in patients with early breast cancer. METHODS AND ANALYSIS: In this multicenter, randomised, controlled phase 2 trial, we will randomly assign 120 women with early breast cancer undergoing chemotherapy to use of a dexamethasone-based elixir or standard oral care, to compare their preventive effects on chemotherapy-induced stomatitis. Patients will be assigned in a 1:1 ratio. Patients in the intervention group will receive chemotherapy, oral care and a dexamethasone-based elixir (10 mL 0.1 mg/mL; swish for 2 min and spit, four times daily for 9 weeks), and patients in the control group will receive chemotherapy and oral care. The primary endpoint is the difference in incidence of stomatitis between the two groups. The sample size allows for the detection of a minimum difference of 20% in the incidence of stomatitis between the two groups. Secondary endpoints are severity of stomatitis, duration of stomatitis, completion rate of chemotherapy and adverse events. ETHICS AND DISSEMINATION: All participants signed a written consent form, and the study protocol has been reviewed and approved by the Clinical Research Review Board of Nagasaki University (CRB7180001). TRIAL REGISTRATION NUMBER: UMIN Clinical Trials Registry (UMIN000030489).

Hybrid vector including polyethylenimine and cationic lipid, DOTMA, for gene delivery.

We developed polyethylenimine (PEI) lipopolyplexes with N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethlylammonium chloride (DOTMA) and pDNA to investigate their usefulness for in vitro and in vivo gene delivery. The charge ratio of the complex to pDNA was calculated with molar values of nitrogen of PEI, and nitrogen of DOTMA to phosphate of pDNA. The polyplexes were prepared at charge ratio 2 (polyplex 2P) and 8 (polyplex 8P). DOTMA solution was added to polyplex 2P to prepare lipopolyplexes at charge ratio 1 (lipopolyplex 2P-1D), 2 (lipopolyplex 2P-2D), and 4 (lipopolyplex 2P-4D). The particle size of the complex was significantly reduced by the addition of DOTMA and settled to 74-114nm, indicating pDNA compaction. The addition of DOTMA to polyplex 2P decreased pDNA dissociation from the complex and degradation in serum. The addition of DOTMA to polyplex 2P remarkably increased gene expression in HepG2 cells in the absence or presence of FBS. These lipopolyplexes showed little cytotoxicity in the presence of FBS. After intravenous injection of the lipopolyplexes into mice, high-gene expression in the liver, spleen, and lung was observed with lipopolyplex 2P-2D, lipopolyplex 2P-4D, and polyplex 8P. In particular, lipopolyplex 2P-4D showed the highest gene expression.

Pulmonary gene delivery of hybrid vector, lipopolyplex containing N-lauroylsarcosine, via the systemic route.

We newly prepared lipopolyplexes containing N-lauroylsarcosine (LS) as a hybrid vector for pulmonary gene delivery via the systemic route. Lipopolyplexes were composed of polyethylenimine (PEI), N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethlylammonium chloride (DOTMA), LS, and plasmid DNA (pDNA). The particle size of lipopolyplex of PEI, DOTMA, and pDNA (lipopolyplex 2P-2D) was not largely changed by the addition of LS, although the addition of LS decreased the high zeta potential. Lipopolyplexes containing LS with low zeta potential showed little aggregation with erythrocytes and low cytotoxicity. In HepG2 cells, lipopolyplexes containing LS showed high transgene efficiency comparable to lipopolyplex 2P-2D. After intravenous injection of the complexes into mice, lipopolyplexes containing LS showed high transgene efficiency, comparable to lipopolyplex 2P-2D. In particular, lipopolyplexes containing LS showed extremely high transgene efficiency in the lung. As a result of the analysis to identify optimum formulations, we discovered that LS contributed to the high transgene efficiency in the lung as 76.7% of the contribution index. These results suggest that lipopolyplexes containing LS are safe and useful gene delivery vectors with lung directivity.