Pickering stabilization mechanism revealed through direct imaging of particles with tuneable contact angle in a phase-separated binary solvent

Pickering emulsions have attracted increasing attention from multiple fields, including food, cosmetics, healthcare, pharmaceutical, and agriculture. Their stability relies on the presence of colloidal particles instead of surfactant at the droplet interface, providing steric stabilization. Here, we demonstrate the microscopic attachment and detachment of particles with tunable contact angle at the interface underlying the Pickering emulsion stability. We vary the interfacial tension continuously by varying the temperature offset of a phase-separated binary liquid from its critical point, and employ confocal microscopy to directly observe the particles at the interface to determine their coverage and contact angle as a function of the varying interfacial tension. When the interfacial tension decreases upon approaching the binary liquid's critical point, the contact angle and detachment energy (ΔE) drop, and the particles move out of the interface. Microscopic imaging suggests necking and capillary interactions lead to clustering of the particles, before they eventually desorb from the interface. Macroscopic measurements show that concomitantly, coalescence takes place, and the emulsion loses its stability. These results reveal the interplay of interfacial energies, contact angle and surface coverage that underlies the Pickering emulsion stability, opening up ways to manipulate and design the stability through the microscopic behavior of the adsorbed particles.

[Real-world clinical data analysis of PARPi as first-line maintenance therapy in newly diagnosed epithelial ovarian cancer patients]

Objective: The real-world clinical data of patients with newly diagnosed ovarian cancer (including fallopian tube cancer and primary peritoneal cancer) who received first-line maintenance therapy with poly adenosine diphosphate ribose polymerase inhibitor (PARPi) were retrospectively analyzed, and the prognostic factors were preliminarily explored. Methods: (1) The clinicopathological data and follow-up data of ovarian cancer patients treated with PARPi first-line maintenance therapy from August 2018 (PARPi was launched in China) to December 31, 2021 in Sichuan Cancer Hospital were collected (real-world clinical data). (2) According to the different types of PARPi, real-world clinical data were divided into olaparib group and niraparib group, which were respectively compared with the inclusion and exclusion criteria of representative domestic and foreign phase Ⅲ randomized controlled trials (RCT), including olaparib as first-line maintenance therapy for advanced ovarian cancer patients with BRCA1/2 gene mutation (SOLO-1 study), niraparib as first-line maintenance therapy (PRIMA study), and niraparib as first-line maintenance therapy for Chinese advanced ovarian cancer patients (PRIME study). (3) The prognosis of the two groups and the prognostic factors were analyzed. Results: (1) A total of 83 patients were included in this study, with a median age of 51 years (47-57 years), including 75 cases of ovarian cancer, 5 cases of fallopian tube cancer, and 3 cases of primary peritoneal cancer; 5 cases of stage Ⅰ, 9 cases of stage Ⅱ, 55 cases of stage Ⅲ, 12 cases of stage Ⅳ, and 2 cases of unknown stage; neoadjuvant chemotherapy (NACT) was performed in 40 cases and non-NACT in 43 cases; 62 cases had no visible residual lesion after surgery (R0), 9 cases had residual disease lesions <1 cm (R1), 8 cases had residual disease lesions ≥1 cm (R2), and 4 cases with unknown postoperative residual disease. Thirty-two cases had PARPi treatment interruption, 40 cases had PARPi reduction, and 1 case terminated treatment due to acute leukemia. Of the 83 patients, 35 were in the olaparib group and 48 were in the niraparib group. The proportion of patients with high-grade serous carcinoma (100% and 75%, respectively) and the proportion of BRCA mutant patients (91% and 10%, respectively) in the olaparib group were higher than those in the niraparib group (all P<0.01). (2) Compared with the inclusion and exclusion criteria of the SOLO-1 study, the olaparib group had only 60% (21/35) coincidence rate; compared with the inclusion and exclusion criteria of PRIMA and PRIME studies, the coincidence rates of niraparib group were only 31% (15/48) and 69% (33/48). The most common reasons for non-compliance were number of chemotherapy courses, histopathological type, and surgical pathological stage. (3) Of the 83 cases received first-line maintenance therapy with PARPi, the median follow-up was 15.9 months (11.3-22.9 months), the median progression-free survival (PFS) was 29.7 months (95%CI: 25.9-33.6 months), and the median overall survival was 49.8 months (95%CI: 47.4-52.2 months). Univariate analysis showed that unilateral or bilateral ovarian cancer, efficacy after platinum-containing chemotherapy, presence or absence of measurable lesions at the end of chemotherapy, and total number of chemotherapy courses were significantly associated with PFS (all P<0.05). Multivariate analysis showed that unilateral or bilateral ovarian cancer, total number of chemotherapy courses, and efficacy after platinum-containing chemotherapy were independent factors affecting PFS in stage Ⅱ-Ⅳ patients with PARPi first-line maintenance therapy (all P<0.05). Conclusions: Unilateral ovarian cancer, the total number of chemotherapy courses no more than 9, and achieving complete response after platinum-containing chemotherapy before maintenance therapy are independent influencing factors of PFS benefit in patients with PARPi first-line maintenance therapy. Due to the large differences between the patients in real clinical practice and the research subjects of phase Ⅲ RCT, the results of representative retrospective studies still have important clinical reference significance.

[The CK2 inhibitor quninalizarin enhances the anti-proliferative effect of icotinib on EGFR-TKIs-resistant cell lines and its underlying mechanisms]

OBJECTIVE

To explore whether quninalizarin, an specific inhibitor of protein kinase CK2, could sensitize icotinib in EGFR-TKIs (epithelial growth factor receptor-tyrosine kinase inhibitor)-resistant cell lines and uncover the underlying mechanisms.

METHODS

MTT assay was performed to evaluate the inhibitory effect of quninalizarin, icotinib or the combination of both on cell proliferation in several lung adenocarcinoma cell lines. Western blot assay was used to assess if combined inhibition of EGFR and protein kinase CK2 by icotinib and quninalizarin, exerts effect on the expression and phosphorylation of major proteins of EGFR signaling pathways.

RESULTS

The IC50 of HCC827, H1650, H1975 and A549 cells for icotinib were (8.07±2.00)μmol/L, (66.01±6.64)μmol/L, (265.60±9.47)μmol/L and (87.88±6.8)μmol/L, respectively, indicating that HCC827 cells are sensitive to icotinib, and the H1650, H1975 and A549 cells are relatively resistant to icotinib. When treated with both quninalizarin and icotinib in the concentration of 50 μmol/L, the viability of H1650, H1975 and A549 cells was (40.64±3.73)%, (65.74±3.27)% and (44.96±0.48)%, respectively, significantly lower than that of H1650, H1975 and A549 cells treated with 50 μmol/L icotinib alone (55.05±1.22)%, (71.98±1.60)% and (61.74±6.18)%, respectively (P<0.01 for all). When treated with both 100 μmol/L quninalizarin and 100 μmol/L icotinib, the viability of H1650, H1975 and A549 ells were (23.35±0.81)%, (55.70±1.03)%, (33.42±1.33)%, respectively, significantly lower than the viability of H1650, H1975 and A549 cells treated with 100 μmol/L icotinib alone (40.57±2.65)%, (62.40±2.05)% and (44.97±8.20)%, respectively, (P<0.01 for all). The two-way ANOVA analysis showed that compared with the viability of EGFR-TKIs-resistant cells (H1650, H1975, A549) treated with 50 μmol/L and 100 μmol/L icotinib alone, the viability of cells treated with icotinib and quinalizarin were significantly suppressed, and the differences were statistically significant (P<0.01). In addition, the phosphorylation form of Akt and ERK (namely p-Akt and p-ERK) were significantly down-regulated by treating with quninalizarin and icotinib together in the H1650 cells while the expression of Akt and ERK changed little.

CONCLUSIONS

Quinalizarin, as a specific CK2 inhibitor, may overcome icotinib resistance by inhibiting proliferation mediated by Akt and ERK in human lung adenocarcinoma cell lines, and enhances the suppressive effect of icotinib on the proliferation of EGFR-TKIs-resistant human lung adenocarcinoma cells.

Compact, magneto-optic Q-switched, neodymium-doped bismuth germinate crystal (Nd:BGO) laser pumped by a laser diode

The magneto-optic Q-switched operation of a neodymium-doped bismuth germinate crystal (Nd:BGO) laser that is end pumped by a cw 500-mW laser diode is reported. The crystal is a new host for Nd lasers. Here it acts as a magneto-optic modulator as well as a laser medium. A pulse energy of 2 µJ with a FWHM of 100 ns has been obtained. The device operates at a repetition rate of 1 kHz, and the fluctuation of the shot-to-shot intensity is less than ±1%.

[The effects of the estradiol control delivery patch in the treatment of 176 cases of ovarian failure]

The effects of the estradiol control delivery patch made in China on the main manifestation in the 176 cases of ovarian failure patient were evaluated with the improvement of their symptoms, the changes of serum levels of LH, FSH, E2, the vaginal exfoliated cytologic maturation index (MI) and the histological alteration of endometrium. The results indicated that the six main symptoms including hectic fever, sweating, vaginal dry and hard-going, dizziness, emotioned lability and insomnia were improved significantly and progressively with prolongation of the treatment. The effective rates were 97.9%, 97.5%, 93.7%, 77.0%, 76.2%, 75.0% respectively form hectic fever to insomnia. The inhibitory effects on serum LH, FSH levels occurred on the 10th day of the treatment. The MI increased within whole course and the serum estradiol level elevated slightly and stably. There were no significant endometrial proliferation caused by the patch.

[Prognosis of dysfunctional uterine bleeding at puberty]

The factors related to the prognosis of dysfunctional uterine bleeding (DUB) at puberty were analysed according to the 2 to 15 years' follow-up examination in 44 cases of pubescent DUB. It was found that the establishment of a regular menstrual cycle depends on the duration of disease. Among 19 cases who established a regular cycle, 12 cases (63.2%), 6 cases (31.2%), 1 case (5.3%) with the duration of disease < or = 4 years, 5 to 10 years, and > or = 11 years respectively. The incidence of gynecologic morbidity of pubescent DUB as referred to transfusion, dilatation and curettage, hysterectomy and polycystic ovarian disease was 19/44, 12/44, 1/44 and 5/44 respectively. Of 30 married patients 28 desired children and four of them conceived spontaneously. 9 cases (37.5%) conceived after ovulation induction. It is suggested that the pubescent DUB should be defined as the onset of DUB occurs within 2 years after menarche. Close following up and timely treatment contribute much to the control of the disease and decrease of gynecologic/morbidity.

Differential effects of 8-bromo-cyclic AMP on human chorionic gonadotropin (hCG), progesterone and estrogen production by term placental cells

The present study examined the effects of a cAMP analog on the output of hCG and progesterone (P) in human term trophoblast cells in culture, as well as the conversion of androstenedione and testosterone to estradiol--17 beta and estrone by these cells. The levels of hCG and P in the culture medium increased throughout the four-day culture period. Addition of 8-bromo-adenosine-3',5'-monophosphate (8-Br-cAMP), forskolin or cholera toxin (but not 8-Br-cGMP) stimulated hCG and P production by the cultivated placental cells. In contrast, the presence of 8-Br-cAMP for 2 days significantly decreased basal estradiol-17 beta output, as well as conversion of androstenedione to estradiol-17 beta; the conversion of androstenedione to estrone was not affected. 8-Br-cAMP attenuated the conversion of testosterone to both estradiol-17 beta and estrone. These results further support the view that cAMP could have both stimulatory and inhibitory actions on placental hormonogenesis.

Induction of polyphosphoinositide breakdown in rat corpus luteum by prostaglandin F2 alpha

The present study examines the possibility that, in the rat corpus luteum, an initial action of prostaglandin F2 alpha (PGF2 alpha) is to induce a ligand-stimulated breakdown of membrane inositol phospholipids. Luteal cells in primary culture were prepared from immature rats after PMSG and human CG priming. In 32P-prelabeled cells, PGF2 alpha caused a rapid decrease in the level of radiolabel found in phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate, as early as 20 sec after addition of the hormones. At 1 and 2.5 min, the effect of 10(-6) M PGF2 alpha on phosphatidylinositol 4,5-bisphosphate was significantly greater than that caused by 10(-6) M LHRH in identical cell cultures. By contrast, the levels of the 32P-prelabeled phosphatidylinositol and phosphatidic acid were increased at 5 min by PGF2 alpha or LHRH. Concomitant with the alterations in cellular levels of 32P-prelabeled phospholipids, PGF2 alpha markedly enhanced the accumulation of 3H-labeled inositol phosphates, i.e. inositol 1-phosphate, inositol diphosphate, and inositol triphosphate, during a 5-min incubation. A significant increase of radiolabeled inositol diphosphate was seen as early as 1 min after the addition of either PGF2 alpha or LHRH; PGF2 alpha was more effective than LHRH in this regard. The stimulatory effect of LHRH on inositol phosphate accumulation could be blocked completely by the concomitant presence of a potent LHRH antagonist, and at the concentration used (10(-6) M) the effects of PGF2 alpha and LHRH were not additive. Interestingly, the addition of an exogenous phospholipase C also caused a similar enhancement of inositol phosphate accumulation in identical cell cultures. For the first time, these data suggest that, at the level of the corpus luteum, hydrolysis of phosphoinositides may immediately follow PGF2 alpha (and to a lesser extent LHRH) receptor binding, and this in turn may lead to the generation of 1,2-diacylglycerol and inositol phosphates, resynthesis of phosphatidic acid and phosphatidylinositol, and mobilization of Ca2+.