Bioinspired gradient scaffolds for osteochondral tissue engineering.

Repairing articular osteochondral defects present considerable challenges in self-repair due to the complex tissue structure and low proliferation of chondrocytes. Conventional clinical therapies have not shown significant efficacy, including microfracture, autologous/allograft osteochondral transplantation, and cell-based techniques. Therefore, tissue engineering has been widely explored in repairing osteochondral defects by leveraging the natural regenerative potential of biomaterials to control cell functions. However, osteochondral tissue is a gradient structure with a smooth transition from the cartilage to subchondral bone, involving changes in chondrocyte morphologies and phenotypes, extracellular matrix components, collagen type and orientation, and cytokines. Bioinspired scaffolds have been developed by simulating gradient characteristics in heterogeneous tissues, such as the pores, components, and osteochondrogenesis-inducing factors, to satisfy the anisotropic features of osteochondral matrices. Bioinspired gradient scaffolds repair osteochondral defects by altering the microenvironments of cell growth to induce osteochondrogenesis and promote the formation of osteochondral interfaces compared with homogeneous scaffolds. This review outlines the meaningful strategies for repairing osteochondral defects by tissue engineering based on gradient scaffolds and predicts the pros and cons of prospective translation into clinical practice.

Engineering Achiral Liquid Crystalline Polymers for Chiral Self-Recovery.

Flexible construction of permanently stored supramolecular chirality with stimulus-responsiveness remains a big challenge. Herein, we describe an efficient method to realize the transfer and storage of chirality in intrinsically achiral films of a side-chain polymeric liquid crystal system by combining chiral doping and cross-linking strategy. Even the helical structure was destroyed by UV light irradiation, the memorized chiral information in the covalent network enabled complete self-recovery of the original chiral superstructure. These results allowed the building of a novel chiroptical switch without any additional chiral source in multiple types of liquid crystal polymers, which may be one of the competitive candidates for use in stimulus-responsive chiro-optical devices.

Elevated expression levels of matrix metalloproteinase-9 in placental villi and tissue inhibitor of metalloproteinase-2 in decidua are associated with prolonged bleeding after mifepristone-misoprostol medical abortion.

OBJECTIVE: To determine whether the expression levels of matrix metalloproteinases 2 and 9 (MMP-2 and -9) and tissue inhibitors of metalloproteinases 1 and 2 (TIMP-1 and -2) in the villi and the decidua are associated with prolonged bleeding after medical abortion. DESIGN: Case-controlled study. SETTING: University hospital. PATIENT(S): Mifepristone-misoprostol medical abortion patients were divided into two groups (20 women each) based on the length of time (>14 or ≤14 days) of bleeding after the abortion. INTERVENTION(S): Discharged villi and deciduas were collected. MAIN OUTCOME MEASURE(S): The expression levels of MMP-2 and -9 and TIMP-1 and -2 in the villi and deciduas were assessed with semiquantitative immunohistochemistry. RESULT(S): The median semiquantitative immunohistochemistry staining index (SI) scores for MMP-9 expression in the villi were elevated in the bleeding group compared with the control group (median SI scores 0.31 and 0.03, respectively). TIMP-2 expression was elevated in the decidua in the bleeding group compared with the control group (median SI scores 1.00 and 0.20, respectively). No significant differences were observed between the two groups in the expression levels of MMP-2 in the villi or of MMP-2, MMP-9, or TIMP-1 or of the ratios of MMP-9/TIMP-1 or MMP-2/TIMP-2 in the decidua. CONCLUSION(S): Elevated expression levels of MMP-9 in the villi and of TIMP-2 in the decidua were associated with prolonged bleeding after medical abortion.

Risk factors for intraoperative hemorrhage at evacuation of a cesarean scar pregnancy following uterine artery embolization.

OBJECTIVE: To determine risk factors associated with massive uterine bleeding during dilation and suction curettage (D&C) after uterine artery embolization (UAE) for the treatment of cesarean scar pregnancy (CSP). METHODS: Data from 128 CSP patients treated with D&C after UAE were analyzed to assess risk factors associated with massive uterine bleeding (blood loss 500mL or more) during D&C after UAE. RESULTS: In total, 15 CSP patients had massive bleeding during D&C after UAE. Univariate analysis showed that a greater gestational age (GA), a larger CSP mass size, a thinner myometrium at the implantation site, a GA of 8weeks or more, a CSP mass diameter of 6cm or more, and evidence of fetal heartbeat were risk factors for massive bleeding (P<0.05). In a binary logistic regression analysis, GA of 8weeks or more and CSP mass diameter of 6cm or more remained as the only significant risk factors for massive bleeding (OR 11.49 [95% CI 1.08-122.13] and OR 96.59 [95% CI 6.20-150.57], respectively; P<0.05). CONCLUSION: For CSP masses with a GA of 8weeks or more and a diameter of 6cm or more, the outcome of surgical evacuation after UAE tends to be unsatisfactory.

Low-dose mifepristone increases uterine expression of aquaporin 1/aquaporin 2 at the time of implantation.

BACKGROUND: The aim of this study was to investigate the mechanism by which low-dose mifepristone serves as an antiimplantation contraceptive drug. A human endometrial explant system was used to study the effects of low-dose mifepristone (65 nmol/L and 200 nmol/L) on expression of the water channel family aquaporins, aquaporin-1 and aquaporin-2 (AQP1/AQP2), at the time of implantation. STUDY DESIGN: Endometrial samples from 17 normally cycling patients at the "window of implantation" were treated with different concentrations of mifepristone. The protein and mRNA expression of AQP1/AQP2 in the endometrium was examined using immunohistochemistry (IHC) and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively. RESULTS: The IHC and RT-PCR analyses demonstrated that expression of AQP1/AQP2 was increased by mifepristone in a dose-dependent manner, with the highest AQP1/AQP2 expression levels detected in subjects treated with 200-nmol/L mifepristone. CONCLUSION: Low-dose mifepristone may negatively regulate implantation by increasing AQP1/AQP2 protein and mRNA expression. The findings from this study provide further evidence to support the potential contraceptive activity of low-dose mifepristone.

Mifepristone increases the cytotoxicity of uterine natural killer cells by acting as a glucocorticoid antagonist via ERK activation.

BACKGROUND: Mifepristone (RU486), a potent antagonist of progesterone and glucocorticoids, is involved in immune regulation. Our previous studies demonstrated that mifepristone directly augments the cytotoxicity of human uterine natural killer (uNK) cells. However, the mechanism responsible for this increase in cytotoxicity is not known. Here, we explored whether the increased cytotoxicity in uNK cells produced by mifepristone is due to either anti-progesterone or anti-glucocorticoid activity, and also investigated relevant changes in the mitogen-activated protein kinase (MAPK) pathway. METHODOLOGY/PRINCIPAL FINDINGS: Uterine NK cells were isolated from decidual samples and incubated with different concentrations of progesterone, cortisol, or mifepristone. The cytotoxicity and perforin expression of uNK cells were detected by mitochondrial lactate dehydrogenase-based MTS staining and flow cytometry assays, respectively. Phosphorylation of components of the MAPK signaling pathway was detected by Western blot. Cortisol attenuated uNK cell-mediated cytotoxicity in a concentration-dependent manner whereas progesterone had no effect. Mifepristone alone increased the cytotoxicity and perforin expression of uNK cells; these effects were blocked by cortisol. Furthermore, mifepristone increased the phosphorylation of ERK1/2 in a cortisol-reversible manner. Specific ERK1/2 inhibitor PD98059 or U0126 blocked cortisol- and mifepristone-induced responses in uNK cells. CONCLUSIONS/SIGNIFICANCE: These results suggest that mifepristone acts as a glucocorticoid antagonist to augment uNK cell-mediated cytotoxicity via ERK activation, which may be caused by increased perforin expression. These observations may reveal an important mechanism by which mifepristone upregulates the cytotoxicity of uNK cells.

Mifepristone may shorten the induction-to-abortion time for termination of second-trimester pregnancies by ethacridine lactate.

BACKGROUND: We reviewed our experience with adding mifepristone to the protocol for the termination of pregnancy up to 24 weeks of gestation by intra-amniotic ethacridine lactate. STUDY DESIGN: The study consisted of women who presented for the termination of a second-trimester pregnancy between August 2000 and July 2008. RESULTS: Of 1245 women who requested a termination of a second-trimester pregnancy, 744 women underwent the induction of abortion by intra-amniotic ethacridine lactate with mifepristone (mifepristone group), and 501 received intra-amniotic ethacridine lactate alone (control group). The proportion of women who delivered within 24 h was 25.94% in the mifepristone group and 10.18% in the control group (p < .001); the failure rate of abortion was 5.38% in the mifepristone group and 4.99% in the control group (p < .001). There was no significant difference in the complication rate between the two groups. The rate of cervical laceration was 0.54% in the mifepristone group and 0.60% in the control group (p = .9315). The rate of retained placental tissue was 6.99% in the mifepristone group and 6.19% in the control group (p = .1112). Nausea was reported by 34.0% of women in the mifepristone group and none in the control group. CONCLUSION: The addition of mifepristone to ethacridine lactate may shorten the induction-to-abortion time compared with the use of ethacridine lactate alone without increasing the number of complications.

Low-dose mifepristone increases uterine natural killer cell cytotoxicity and perforin expression during the receptive phase.

OBJECTIVE: To investigate the immunologic mechanism by which low-dose mifepristone serves as an anti-implantation contraceptive drug. DESIGN: In vitro study. SETTING: University hospital and research laboratory. PATIENT(S): Fifteen normally cycling patients at the "window of implantation." INTERVENTION(S): A human endometrial explant system was used to study the effects of low-dose mifepristone (65 and 200 nmol/L) on uterine natural killer (uNK) cells. Endometrial samples were treated with different concentrations of mifepristone. MAIN OUTCOME MEASURE(S): The cytotoxicity of uNK cells to K562 target cells and the expression of perforin (PFN) by uNK cells were examined using a methyl thiazolyl tetrazolium (MTT) assay and double immunohistochemistry, respectively. RESULT(S): Both uNK cell cytotoxicity and expression of PFN were increased after treatment with 65 or 200 nmol/L mifepristone, and these effects were dose-dependent. CONCLUSION(S): Mifepristone may negatively regulate implantation by increasing the cytotoxicity of uNK cells, and this increased cytotoxicity may result from increased PFN expression. These findings provide further evidence to support the potential contraceptive activity of low-dose mifepristone.

Effects of low-dose mifepristone administration in two different 14-day regimens on the menstrual cycle and endometrial development: a randomized controlled trial.

BACKGROUND: This study was conducted to evaluate the effects of treatment with mifepristone 5 mg given every day or every other day for 14 days, starting 15 days after menses started for endometrial development. STUDY DESIGN: Ten women recruited to the study were given mifepristone 5 mg beginning 15 days after initiation of menses. In Group A, five women were administered mifepristone every day for three cycles; in Group B, five women were administered mifepristone every other day for three cycles. The effects on the menstrual cycle and endometrial development were investigated. RESULTS: Following these treatments with mifepristone 5 mg, there was slight suppression of ovulation in both treatment cycles compared with control cycles. The follicular phase in subsequent cycles was prolonged after daily treatment with mifepristone, which was not observed after administration every other day. In addition, continuous treatment increased progesterone receptor (PR) expression and reduced leukemia inhibitory factor (LIF) expression in the endometrial epithelium. CONCLUSION: Treatment with low-dose mifepristone every day or every other day starting 15 days after initiation of menses retards endometrial development and impairs endometrial receptivity but has minor effects on the menstrual cycle.

Effect of human endometrial stromal cell-derived conditioned medium on uterine natural killer (uNK) cells' proliferation and cytotoxicity.

PROBLEM: Human endometrial stromal cells are involved in the regulation of immune cell proliferation, apoptosis, differentiation, and function. In the endometrium, uNK cells are in close contact with stromal cells. The aim of the study was to investigate the effects of human endometrial stromal cells on uNK-cell proliferation and uNK-cell cytotoxicity. METHOD OF STUDY: The conditioned medium was derived from the endometrial stromal cells in the proliferative phase, secretory phase, and early pregnancy. The effects of stromal cell-derived conditioned medium on uNK-cell proliferation and cytotoxicity were detected by mitochondrial lactate dehydrogenase-based MTS staining and flow cytometry. RESULTS: The stromal cell-derived conditioned medium in both secretory phase and early pregnancy significantly promoted uNK-cell proliferation. Compared with the control group, the uNK-cell cytotoxicity were significantly reduced by conditioned medium in the proliferative, secretory, and decidua groups, but there were no significant differences among these different physiological stages in the inhibiting ability. CONCLUSION: Human endometrial stromal cells may be involved in the regulation of uNK-cell functions through influencing proliferation and cytolytic activity.

The effect of phloroglucinol on pain in first-trimester surgical abortion: a double-blind randomized controlled study.

BACKGROUND: First-trimester surgical abortion is a common procedure. Pain control during this procedure is still an unsolved problem. STUDY DESIGN: In this randomized, double-blind placebo-controlled study, women presenting for first-trimester surgical abortion received intramuscular phloroglucinol (4 mL) or placebo (normal saline, 4 mL). Visual analog scales (VAS) for pain immediately and 30 min after the procedure and side effects of the drug were recorded. RESULTS: There was no significant difference between groups in the pain level immediately and 30 min after the procedure; 70.7% of the phloroglucinol group (n=58 cases) and 56.9% of the placebo group (n=58 cases ) reported mild pain; 27.6% and 34.5%, respectively, reported moderate pain; and 1.7% and 8.6%, respectively, reported severe pain. Thirty minutes after the procedure, the median pain score was reduced to 1.3 in both groups. Postoperative side effects were reported, but there was no significant difference between groups for nausea or vomiting and blood pressure. CONCLUSION: The use of this dose of phloroglucinol, during first-trimester abortion by suction evacuation under local anesthesia with lidocaine, did not relieve pain, but caused no side effects.

The effect of mifepristone on the peripheral blood natural killer cell's cytotoxicity and expression of CD94/NKG2A and NKG2D during the implantation phase.

OBJECTIVE: To investigate the effect of mifepristone on peripheral blood natural killer cell's (pbNK) cytotoxicity and the expression of the inhibitory receptor CD94/NKG2A and the activated receptor NKG2D on pbNK cells. DESIGN: In vitro study. SETTING: University hospital and research laboratory. PATIENT(S): Twenty healthy nonpregnant women. INTERVENTION(S): Detected the cytolytic activity of pbNK to K562 target cells; measured the expression of CD94/NKG2A and NKG2D on pbNK. MAIN OUTCOME MEASURE(S): Cytotoxicity of pbNK was detected by Methyl thiazolyl tetrazolium. The expression of CD94/NKG2A and NKG2D receptor on pbNK cells were detected by flow cytometry. RESULT(S): The NK cell cytotoxicity and the expression of inhibitory receptor CD94/NKG2A during the proliferative phase (81.71 +/- 11.5, 86.6 +/- 9.0) was significantly higher than the secretory phase (60.16 +/- 19.2, 60.15 +/- 31.0). The NK cells cytotoxicity, after being treated with mifepristone and the expression of inhibitory receptor CD94/NKG2A on pbNK cells treated with 200 nmol/L mifepristone, were significantly increased. Mifepristone had no effect on the expression of activating receptor NKG2D. CONCLUSION(S): These data suggest that Mifepristone maybe exert its anti-implantation function by increasing NK cytotoxicity. The increasing NK cytotoxicity of mifepristone is not related to CD94/NKG2A and NKG2D. In the secretory phase down-regulated CD94/NKG2A, NKG2D, and NK cytotoxicity may benefit with embryo implantation.

Uterine artery embolization compared with methotrexate for the management of pregnancy implanted within a cesarean scar.

OBJECTIVE: The objective of the study was to compare the efficacy and safety of uterine artery embolization (UAE) vs systemic methotrexate (MTX) for pregnancy within a cesarean scar. STUDY DESIGN: Seventy-two women with pregnancy within cesarean scar were randomly allocated to a UAE group (37 cases) or an MTX group (35 cases), which all was followed by suction curettage. The primary outpoints include bleeding loss, serum beta-human chorionic gonadotropin level, and side effects. RESULTS: The bleeding volumes were 36.93 +/- 6.01 mL in the UAE group and 415.63 +/- 68.37 mL in the MTX group (P < .001). The hospitalization time was 11.73 +/- 0.80 days in the UAE group and 39.63 +/- 4.57 days in the MTX group (P < .001). There was no severe side effect in both groups. CONCLUSION: For pregnancy within a cesarean scar, UAE followed by suction curettage appears to have more advantage and may be a priority option.

Mifepristone as an anti-implantation contraceptive drug: roles in regulation of uterine natural killer cells during implantation phase.

PROBLEM: To investigate the immunological mechanism of low-dose mifepristone acting as a contraceptive at the level of the endometrium. METHOD OF STUDY: Endometrial explants were cultured in vitro with or without mifepristone treatment for 24 hr. Some tissues were fixed and immunostained for CD56, while other tissues were dissociated and cells analysed by three colour flow cytometry for CD3, CD56 and CD16. RESULTS AND CONCLUSION: Results showed a significant increase in the number of CD56(+) natural killer (NK) cells and the percentages of CD3(-) CD56(+) CD16(-) NK cell subset in the tissue treated with mifepristone, while the percentage of CD3(-) CD56(+) CD16(+) NK cell subset remained unaffected. It shows that low-dose mifepristone increases the number of CD56(+) NK cells and the percentage of CD3(-) CD56(+) CD16(-) NK subset in receptive endometrium and provides new insights into the immunological mechanism of low-dose mifepristone as an anti-implantation contraceptive drug.

[Treatment of pregnancy in a previous caesarean section scar with uterine artery embolization: analysis of 60 cases].

OBJECTIVE: To evaluate the security and effectiveness of uterine artery embolization (UAE) in treatment of pregnancy in uterine caesarean scar compared with medicine treatment. METHODS: Sixty patients with pregnancies in uterine caesarean scar were divided into medicine group (n = 31) that received intravenous injection of methotrexate (MTX) 100 mg once or MTX 20 mg once a day for 5 days as the first course, received the second course when the serum beta-human chorionic gonadotropin (HCG) decreased to the level as < 50%, and then underwent uterine curettage; and UAE group (n = 29) that underwent catheterization into the left uterine artery and then uterine curettage 48h after the successful embolization. The bleeding volume during suction curettage, side effects, admission day, and menstruation recover time were recorded. RESULTS: The hospital stay of the UAE group was (14.4 +/- 1.67) days, significantly shorter than that of the medicine group [(39.3 +/- 4.71) days, P < 0.05]. No patient had to receive hysterectomy in the UAE group but 2 in the medicine group underwent hysterectomy. Seven patients showed liver dysfunction and 8 patients had nausea and slight vomit in the medicine group, and 15 patients with fever and 10 with light post-embolization syndromes were found in the UAE group. Menstruation resumed normal in all patients of the 2 groups one or two months later. CONCLUSION: With the advantage of low risk of heavy bleeding and shorter admission day, UAE is safe and effective in treatment of pregnancy in uterine caesarean scar.

The effect of mifepristone on apoptosis and caspase-3 activation in human ovarian luteinized granulosa cells.

OBJECTIVE: To investigate the effect of mifepristone, an oral contraceptive, on apoptosis in human ovarian luteinized granulosa cells. STUDY DESIGN: Human ovarian luteinized granulosa cells were treated in vitro with 1.25, 2.5, 5.0, 10.0, or 20.0 microM of mifepristone. Nuclear morphology, apoptosis ratio, and level of caspase-3 expression were determined with immunofluorescence microscopy, the terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL) assay, and flow cytometry. RESULTS: We found that mifepristone-treated cells contained single condensed chromatin with multiple nuclear fragments, which is morphologic evidence of apoptosis. A significant difference was observed in the TUNEL assay between mifepristone-treated cells and control cells (P<0.05). Consistent with the results of the TUNEL assay, the fluorescence intensity of caspase-3 in drug-treated cells was also significantly different (P<0.05) from control cells; specifically, the difference between cells treated with different doses of drugs was much smaller and negligible. CONCLUSION: From these results, we propose that mifepristone induces human ovarian luteinized granulosa cells to undergo apoptosis by activating caspase-3.