Highly Bioactive MXene-M2-Exosome Nanocomposites Promote Angiogenic Diabetic Wound Repair through Reconstructing High Glucose-Derived Immune Inhibition.

The repair of diabetic wounds remains challenging, primarily due to the high-glucose-derived immune inhibition which often leads to the excessive inflammatory response, impaired angiogenesis, and heightened susceptibility to infection. However, the means to reduce the immunosuppression and regulate the conversion of M2 phenotype macrophages under a high-glucose microenvironment using advanced biomaterials for diabetic wounds are not yet fully understood. Herein, we report two-dimensional carbide (MXene)-M2 macrophage exosome (Exo) nanohybrids (FM-Exo) for promoting diabetic wound repair by overcoming the high-glucose-derived immune inhibition. FM-Exo showed the sustained release of M2 macrophage-derived exosomes (M2-Exo) up to 7 days and exhibited broad-spectrum antibacterial activity. In the high-glucose microenvironment, relative to the single Exo, FM-Exo could significantly induce the optimized M2a/M2c polarization ratio of macrophages by activating the PI3K/Akt signaling pathway, promoting the proliferation, migration of fibroblasts, and angiogenic ability of endothelial cells. In the diabetic full-thickness wound model, FM-Exo effectively regulated the polarization status of macrophages and promoted their transition to the M2 phenotype, thereby inhibiting inflammation, promoting angiogenesis through VEGF secretion, and improving proper collagen deposition. As a result, the healing process was accelerated, leading to a better healing outcome with reduced scarring. Therefore, this study introduced a promising approach to address diabetic wounds by developing bioactive nanomaterials to regulate immune inhibition in a high-glucose environment.

Advances in mesenchymal stem cells therapy for tendinopathies.

Tendinopathies are chronic diseases of an unknown etiology and associated with inflammation. Mesenchymal stem cells (MSCs) have emerged as a viable therapeutic option to combat the pathological progression of tendinopathies, not only because of their potential for multidirectional differentiation and self-renewal, but also their excellent immunomodulatory properties. The immunomodulatory effects of MSCs are increasingly being recognized as playing a crucial role in the treatment of tendinopathies, with MSCs being pivotal in regulating the inflammatory microenvironment by modulating the immune response, ultimately contributing to improved tissue repair. This review will discuss the current knowledge regarding the application of MSCs in tendinopathy treatments through the modulation of the immune response.

Overcoming Low C2+ Yield in Acidic CO2 Electroreduction: Modulating Local Hydrophobicity for Enhanced Performance.

Operating electrochemical CO2 reduction reaction (CO2 RR) in acidic media has garnered considerable attention due to its sustainable electrolyte cycling and stable performance. Nevertheless, the severe parasitic hydrogen evolution reaction (HER) and decayed multi-carbon species (C2+ ) yield still hampers efficient CO2 RR in acid. Here, this work investigates the influence of local hydrophobicity on the acidic CO2 RR. By employing direct electrodeposition, the hydrophobicity of the catalyst layer can be finely tuned over a wide range without additive. It is revealed that the hydrophobic microenvironment significantly suppressed HER, improved CO2 RR performance and boosted C2+ yield. A Faradaic efficiency (FE) of ≈74% for C2+ is achieved in pH = 2 on electrodeposited copper with a highly hydrophobic environment. Moreover, this phenomenon can be extended to industrial application. An ≈81% total FE for the CO2 RR, along with a ≈62% FE for C2+ species, is achieved even with commercial copper. Remarkably, the system exhibited stable operation for a continuous period exceeding 50 h at an industrially applied current density of 300 mA cm-2 . This work highlights the crucial role of interface hydrophobicity in acidic CO2 RR and proposes a facile and universally applicable method for achieving efficient and stable CO2 RR to high-value products in acidic media.

Nuciferine improves random skin flap survival via TFEB-mediated activation of autophagy-lysosomal pathway.

Due to their simplicity and reliability, random-pattern skin flaps are commonly utilized in surgical reconstruction to repair cutaneous wounds. However, the post-operative necrosis frequently happens because of the ischemia and high-level of oxidative stress of random skin flaps, which can severely affect the healing outcomes. Earlier evidence has shown promising effect of Nuciferine (NF) on preventing hydrogen peroxide (H2O2)-induced fibroblast senescence and ischemic injury, however, whether it can function on promoting ischemic flap survival remains unknown. In this work, using network pharmacology analysis, it was possible to anticipate the prospective targets of NF in the context of ischemia. The results revealed that NF treatment minimized H2O2-induced cellular dysfunction of human umbilical vein endothelial cells (HUVECs), and also improved flap survival through strengthening angiogenesis and alleviating oxidative stress, inflammation and apoptosis in vivo. These outcomes should be attributed to TFEB-mediated enhancement of autophagy-lysosomal degradation via the AMPK-mTOR signaling pathway, whilst the restriction of autophagy stimulation with 3MA effectively diminished the above advantages of NF treatment. The increased nuclear translocation of TFEB not only restored lysosome function, but also promoted autophagosome-lysosome fusion, eventually restoring the inhibited autophagic flux and filling the high energy levels. The outcomes of our research can provide potent proof for the application of NF in the therapy of vascular insufficiency associated disorders, including random flaps.

Global, regional, and national burden of chronic respiratory diseases and associated risk factors, 1990-2019: Results from the Global Burden of Disease Study 2019.

Background: The burden of chronic respiratory diseases has changed over the three decades. This study aims to describe the spatiotemporal trends of prevalence, mortality, and disability-adjusted life years (DALY) due to chronic respiratory diseases (CRDs) worldwide during 1990-2019 using data from the Global Burden of Disease Study 2019 (GBD 2019). Methods: The prevalence, mortality, and DALY attributable to CRDs and risk factors from 1990 to 2019 were estimated. We also assessed the driving factors and potentiality for improvement with decomposition and frontier analyses, respectively. Results: In 2019, 454.56 [95% uncertainty interval (UI): 417.35-499.14] million individuals worldwide had a CRD, showing a 39·8% increase compared with 1990. Deaths due to CRDs were 3.97 (95%UI: 3.58-4.30) million, and DALY in 2019 was 103.53 (95%UI: 94.79-112.27) million. Declines by average annual percent change (AAPC) were observed in age-standardized prevalence rates (ASPR) (0.64% decrease), age-standardized mortality rates (ASMR) (1.92%), and age-standardized DALY rates (ASDR) (1.72%) globally and in 5 socio-demographic index (SDI) regions. Decomposition analyses represented that the increase in overall CRDs DALY was driven by aging and population growth. However, chronic obstructive pulmonary disease (COPD) was the leading driver of increased DALY worldwide. Frontier analyses witnessed significant improvement opportunities at all levels of the development spectrum. Smoking remained a leading risk factor (RF) for mortality and DALY, although it showed a downward trend. Air pollution, a growing factor especially in relatively low SDI regions, deserves our attention. Conclusion: Our study clarified that CRDs remain the leading causes of prevalence, mortality, and DALY worldwide, with growth in absolute numbers but declines in several age-standardized estimators since 1990. The estimated contribution of risk factors to mortality and DALY demands the need for urgent measures to improve them. Systematic review registration: http://ghdx.healthdata.org/gbd-results-tool.

A Novel Anti-Osteoporosis Mechanism of VK2: Interfering with Ferroptosis via AMPK/SIRT1 Pathway in Type 2 Diabetic Osteoporosis.

Type 2 diabetic osteoporosis (T2DOP) is a chronic bone metabolic disease. Compared with traditional menopausal osteoporosis, the long-term high glucose (HG) microenvironment increases patients' risk of fracture and osteonecrosis. We were accumulating evidence that implicated ferroptosis as a pivotal mechanism of glucolipotoxicity-mediated death of osteocytes and osteoblast, a novel form of programmed cell death resulting from uncontrolled lipid peroxidation depending on iron. Vitamin K2 (VK2), a fat-soluble vitamin, is clinically applied to prevent osteoporosis and improve coagulation. This study aimed to clarify the role and mechanism of VK2 in HG-mediated ferroptosis. We established the mouse T2DOP model by intraperitoneal injection of streptozotocin solution and a high-fat and high-sugar diet. We also cultured bone marrow mesenchymal stem cells (BMSCs) in HG to simulate the diabetic environment in vitro. Based on our data, VK2 inhibited HG-mediated bone loss and ferroptosis, the latter manifested by decreased levels of mitochondrial reactive oxygen species, lipid peroxidation, and malondialdehyde and increased glutathione in vitro. In addition, VK2 treatment was capable of restoring bone mass and strengthening the expression of SIRT1, GPX4, and osteogenic markers in the distal femurs. As for further mechanism exploration, we found that VK2 could activate AMPK/SIRT1 signaling, and knockdown of SIRT1 by siRNA prevented the VK2-mediated positive effect in HG-cultured BMSCs. Summarily, VK2 could ameliorate T2DOP through the activation of the AMPK/SIRT1 signaling pathway to inhibit ferroptosis.

Activation of ß2-adrenergic Receptor Ameliorates Amyloid-ß-induced Mitophagy Defects and Tau Pathology in Mice.

Defective mitophagy and mitochondrial dysfunction have been linked to aging and Alzheimer's disease (AD). ß2-Adrenergic receptor (ADRB2) is critical for mitochondrial and cognitive function. However, researchers have not clearly determined whether ADRB2 activation ameliorates defective mitophagy and cognitive deficits in individuals with AD. Here, we observed that the activation of ADRB2 by clenbuterol (Clen, ADRB2 agonist, 2 mg/kg/day) ameliorated amyloid-ß-induced (Aß1-42 bilateral intracerebral infusion, 2 µl, 5 µg/µl) memory deficits. Activation of ADRB2 also attenuated Aß-induced mitochondrial dysfunction, as revealed by increased ATP levels, mitochondrial membrane potential (MMP/Δψm) and complex I activity. Further studies revealed that ADRB2 activation restored mitophagy deficits, as revealed by the increased light chain 3 (LC3)-II/LC3-I ratio, Atg5 levels, and Atg7 levels and decreased p62 levels, along with the upregulation of PTEN-induced putative kinase 1 (PINK1), Parkin and NAD+ levels. Activation of ADRB2 rescued Aß-induced oxidative stress and neuronal death. ADRB2 activation also attenuated Aß-induced tau hyperphosphorylation by regulating glycogen synthase kinase-3ß expression in the hippocampus. Finally, we established that Clen improved mitophagy and attenuated mitochondrial dysfunction, and tau pathology in mice by activating the ADRB2/Akt/PINK1 signaling pathway. Conversely, the inhibition of ADRB2 by propranolol (ßAR antagonist, 10 µM) blocked the Clen-mediated improvements in pathological changes in N2a cells. The results from the present study indicate that ADRB2 activation may be a therapeutic strategy for AD.

CORM-3 Attenuates Oxidative Stress-Induced Bone Loss via the Nrf2/HO-1 Pathway.

Bone metabolism occurs in the entire life of an individual and is required for maintaining skeletal homeostasis. The imbalance between osteogenesis and osteoclastogenesis eventually leads to osteoporosis. Oxidative stress is considered a major cause of bone homeostasis disorder, and relieving excessive oxidative stress in bone mesenchymal stem cells (BMSCs) is a potential treatment strategy for osteoporosis. Carbon monoxide releasing molecule-3 (CORM-3), the classical donor of carbon monoxide (CO), possesses antioxidation, antiapoptosis, and anti-inflammatory properties. In our study, we found that CORM-3 could reduce reactive oxygen species (ROS) accumulation and prevent mitochondrial dysfunction thereby restoring the osteogenic potential of the BMSCs disrupted by hydrogen peroxide (H2O2) exposure. The action of CORM-3 was preliminarily considered the consequence of Nrf2/HO-1 axis activation. In addition, CORM-3 inhibited osteoclast formation in mouse primary bone marrow monocytes (BMMs) by inhibiting H2O2-induced polarization of M1 macrophages and endowing macrophages with M2 polarizating ability. Rat models further demonstrated that CORM-3 treatment could restore bone mass and enhance the expression of Nrf2 and osteogenic markers in the distal femurs. In summary, CORM-3 is a potential therapeutic agent for the treatment of osteoporosis.

MDL-800, the SIRT6 Activator, Suppresses Inflammation via the NF-κB Pathway and Promotes Angiogenesis to Accelerate Cutaneous Wound Healing in Mice.

Sirtuin 6 (SIRT6) is an NAD+-dependent deacetylase belonging to the sirtuin family. It has been shown to participate in wound healing and some inflammation-related disorders. However, the effect of MDL-800, a highly efficient and selective SIRT6 activator, on wound healing and inflammation has not been reported. Therefore, this study investigated whether MDL-800 confers anti-inflammatory effects and promotes wound healing and uncovered the molecular mechanisms involved. This was achieved using mouse models of full-thickness wounds. Results showed that MDL-800 significantly downregulated inflammation by attenuating the release of inflammatory mediators and improved collagen deposition and neovascularization of wounds, thereby accelerating cutaneous wound healing. Furthermore, MDL-800 significantly downregulated expression levels of TNF-α and IL-6 in the dorsal skin tissue of mice via the NF-κB pathway. These results demonstrated that MDL-800 exerted anti-inflammatory and prohealing effects, indicating that the SIRT6/NF-κB/IκB signaling pathway may play an important role in wound healing.

Zwitterionic Hydrogel Activates Autophagy to Promote Extracellular Matrix Remodeling for Improved Pressure Ulcer Healing.

Pressure ulcer (PU) is a worldwide problem that is hard to heal because of its prolonged inflammatory response and impaired ECM deposition caused by local hypoxia and repeated ischemia/reperfusion. Our previous study discovered that the non-fouling zwitterionic sulfated poly (sulfobetaine methacrylate) (SBMA) hydrogel can improve PU healing with rapid ECM rebuilding. However, the mechanism of the SBMA hydrogel in promoting ECM rebuilding is unclear. Therefore, in this work, the impact of the SBMA hydrogel on ECM reconstruction is comprehensively studied, and the underlying mechanism is intensively investigated in a rat PU model. The in vivo data demonstrate that compared to the PEG hydrogel, the SBMA hydrogel enhances the ECM remolding by the upregulation of fibronectin and laminin expression as well as the inhibition of MMP-2. Further investigation reveals that the decreased MMP-2 expression of zwitterionic SBMA hydrogel treatment is due to the activation of autophagy through the inhibited PI3K/Akt/mTOR signaling pathway and reduced inflammation. The association of autophagy with ECM remodeling may provide a way in guiding the design of biomaterial-based wound dressing for chronic wound repair.

Hybrids of arenobufagin and benzoisoselenazol reducing the cardiotoxicity of arenobufagin.

Arenobufagin is a naturally occurring bufadienolide showing promising antitumor activity accompanied however with apparent cardiac toxicity. Following the recent discovery that oxidative damage possibly be an important cause of the cardiac toxicity of cardenolides, a strategy fusing the antitumor agent arenobufagin with a benzoisoselenazol fragment, a reactive oxygen species (ROS) scavenger, has been developed. Six novel hybrids were synthesized and their ROS scavenging activities as well as their in vitro cytotoxicity against the human hepatocellular carcinoma cell line HepG2, an adriamycin-resistant subline HepG2/ADM, and the human myocardial cell line AC16 were evaluated. The results indicate that the hybrids exhibit various degrees of in vitro ROS scavenging activities, and weaker cytotoxicity than that of arenobufagin against the myocardial cell line AC16. These findings suggest the feasibility of a strategy in which the cardiotoxicity of the potential antitumor agent arenobufagin is reduced.

Protective effect of salidroside on rats with hypoxic pulmonary hyperten-sion by suppressing oxidative stress / 中国病理生理杂志

AIM:To study whether salidroside plays a protective role in hypoxia-induced pulmonary hyperten-sion by suppressing oxidative stress.METHODS: Sprague-Dawley rats were randomly divided into 4 groups: normoxia (N)group,hypoxia for 4 weeks(H4)group,low-dose salidroside(hypoxia for 4 weeks and treatment with salidroside at 16 mg/kg,H4S16)group and high-dose salidroside(hypoxia for 4 weeks and treatment with salidroside at 32 mg/kg, H4S32)group.The mean pulmonary arterial pressure(mPAP), the weight ratio of right ventricle/(left ventricle+sep-tum)[RV/(LV+S)]and vessel wall area/vessel total area(WA/TA)were evaluated.The levels of malondialdehyde (MDA)in the serum and lung tissues were detected by colorimetric method.The levels of 8-iso-prostaglandin F2α(8-iso-PGF2α)in the serum and lung tissues were measured by ELISA.The activity of superoxide dismutase(SOD)in the serum was analyzed by hydroxylamine method.The expression of NAPDH oxidase 4(NOX4)and SOD1 in the lung tissues was determined by Western blot.RESULTS:Compared with N group,the levels of mPAP,RV/(LV+S)and WA/TA in H4 group were significantly increased,which were apparently attenuated by salidroside injection in a dose-dependent manner. Meanwhile,salidroside administration apparently decreased the levels of MDA and 8-iso-PGF2αin the serum and lung tis-sues,as well as the expression of NOX 4 in the lung tissues.Besides,compared with N group, the activity of SOD in the serum and the expression of SOD1 in the lung tissues in H4group were significantly decreased,while administration of sali-droside increased the activity of SOD in the serum and the expression of SOD 1 in the lung tissues in a dose-dependent man-ner.CONCLUSION:Salidroside protects the pulmonary vessels from remodeling and attenuates hypoxia -induced pulmo-nary hypertension by inhibiting oxidative stress.

Human type H vessels are a sensitive biomarker of bone mass.

Vascularization is fundamental for bone formation and bone tissue homeostasis. However, in human subjects, a direct molecular relationship has not been identified between angiogenesis and agents that promote bone disease or factors related to age. Osteopenia is a condition in which bone mineral density is lower than normal, and it represents a sign of normal aging. Here we tested whether the type H vessel, which was recently identified as strongly positive for CD31 and Endomucin (CD31hiEmcnhi) in mice, is an important indicator of aging and osteopenia in human subjects. We found that age-dependent losses of type H vessels in human bone sections conform to the observations in aged mice. The abundance of human type H vessels and osteoprogenitors may be relevant to changes in the skeletal microarchitecture and advanced osteopenia. Furthermore, ovariectomized mice, a widely used model for postmenopausal osteoporosis, exhibited significantly reduced type H vessels accompanied by reduced osteoprogenitors, which is consistent with impaired bone microarchitecture and osteoporosis, suggesting that this feature is an indicator of bone mass independent of aging. More importantly, administration of desferrioxamine led to significantly increased bone mass via enhanced angiogenesis and increased type H vessels in ovariectomized mice. Altogether, these data represent a novel finding that type H vessels are regulated in aged and osteopenia subjects. The abundance of human type H vessels is an early marker of bone loss and represents a potential target for improving bone quality via the induction of type H vessels.

[Frenulum identification positioning with a disposable suture device in circumcision to prevent postoperative penile frenulum malposition].

OBJECTIVE: To investigate the effect of the frenulum identification positioning method with a disposable suture device in circumcision for the prevention of postoperative penile frenulum malposition. METHODS: Totally 212 patients with phimosis or redundant prepuce underwent circumcision from March 2015 to September 2016, including 109 cases of conventional circumcision (the control group) and 103 cases treated by frenulum identification positioning with a disposable suture device (the observation group). We observed the postoperative position of the penile frenulum and median raphe and compared the deviation angles of the frenulum between the two groups of patients. RESULTS: The median of penile frenulum deviation angle (interquartile range) was 0 (3.56) in the observation group, significantly smaller than 12.41 (19.59) in the control (P <0.001, P = 0.000). And the rate of frenulum deviation was remarkably lower in the former (8.74% ï¼»9/103ï¼½) than in the latter group (66.06% ï¼»72/109ï¼½) (P <0.01). CONCLUSIONS: Circumcision using the frenulum identification positioning method with a disposable suture device can effectively avoid postoperative penile frenulum malposition. With the advantages of safety and easy operation, it deserves clinical application and popularization.

A piperazidine derivative of 23-hydroxy betulinic acid induces a mitochondria-derived ROS burst to trigger apoptotic cell death in hepatocellular carcinoma cells.

BACKGROUND: Elevated production of reactive oxygen species (ROS) and an altered redox state have frequently been observed in hepatocellular carcinoma (HCC); therefore, selective killing of HCC cells by chemotherapeutic agents that stimulate ROS generation or impair antioxidant systems may be a feasible approach in HCC chemotherapy. Recently, betulinic acid and its derivatives have attracted attention because they showed anti-cancer effects via a ROS- and mitochondria-related mechanism. However, the source of ROS overproduction and the role of mitochondria were poorly identified, and the weak in vivo antitumour activity of these compounds limits their development as drugs. METHODS: Cytotoxicity was detected using MTT assays. In vivo anti-HCC effects were assessed using nude mice bearing HepG2 tumour xenografts. Cell cycle analysis, apoptosis rate and mitochondrial membrane potential were measured by flow cytometry. ROS production was detected using a microplate reader or a fluorescence microscope. Changes in gene and protein levels were measured by RT-PCR and western blotting, respectively. Other assays were performed using related detection kits. RESULTS: B5G9, a piperazidine derivative of 23-hydroxy betulinic acid (23-HBA), showed excellent in vivo anti-HCC effects, with a tumour growth inhibitory rate of greater than 80%, and no significant side effects. B5G9 stimulated the production of ROS, which were derived from the mitochondria, but it had no effect on various other antioxidant systems. Moreover, B5G9 induced mitochondrial dysfunction, which was characterized by morphological changes, membrane potential collapse, membrane permeabilization, and decreases in the O2 consumption rate and ATP production. Furthermore, mtDNA-depleted ρ0 HepG2 cells were less sensitive to B5G9 treatment than wt HepG2 cells, indicating the importance of mitochondria in B5G9-induced cell death. CONCLUSION: We discovered a piperazidine derivative of 23-HBA, B5G9, with excellent anti-HCC effects both in vivo and in vitro and no obvious toxic effects. The underlying mechanism was associated with mitochondria-derived ROS overproduction, and mitochondria played essential roles in B5G9-induced cell death. This study identified a potential agent for anti-HCC therapy and elucidated the mitochondria-related mechanism of BA and its derivatives.

B4G2 induces mitochondrial apoptosis by the ROS-mediated opening of Ca(2+)-dependent permeability transition pores.

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) is the most common type of liver cancer. At present, only sorafenib is approved to treat HCC. In this study, we found that a 23-hydroxybetulinic acid derivative, B4G2, exhibited potent antiproliferative activity in HCC cell lines. METHODS: We used four HCC cell lines (HepG2, HepG2/ADM, Hep3B and Bel-7402) to evaluate the anti-tumour activity and explore underlying mechanisms by which B4G2 induces apoptosis. RESULTS: Among these cell lines, HepG2 showed the highest sensitivity to B4G2. HepG2 cells treated with B4G2 showed a depolarized mitochondrial membrane potential, released cytochrome c, activated caspase-9 and caspase-3 and cleaved poly ADP-ribose polymerase (PARP). However, Z-VAD-FMK, a pan-caspase inhibitor, did not attenuate B4G2-induced apoptosis, implying that the induction of mitochondrial apoptosis by B4G2 may be independent of caspases. Moreover, pre-treatment with MgCl2, a blocker of Ca2+-dependent permeability transition (PT) pores, attenuated the depolarization of the mitochondrial potential and decreased the population of apoptotic cells, indicating that B4G2-induced apoptosis was partly dependent on the opening of the Ca2+-dependent PT pores. B4G2 also increased the levels of intracellular calcium and reactive oxygen species (ROS). Furthermore, an ROS scavenger, N-acetyl-cysteine (NAC), markedly decreased the accumulation of intracellular calcium and apoptosis. CONCLUSION: This is the first demonstration that B4G2 inhibits the growth of HCC cells and induces mitochondrial apoptosis in hepatocellular carcinoma cells by the ROS-mediated opening of Ca2+-dependent permeability transition pores.

One-step strategy for the synthesis of a derivatized cyclodextrin-based monolithic column.

Derivatized ß-cyclodextrin (ß-CD) functionalized monolithic columns were prepared by a "one-step" strategy using click chemistry. First, the intended derivatized ß-CD monomers were synthesized by a click reaction between propargyl methacrylate and mono-6-azido-ß-CD and then sulfonation or methylation was carried out. Finally, monolithic columns were prepared through a one-step in situ copolymerization of the derivatized ß-CD monomer and ethylene glycol dimethacrylate. The sulfated ß-CD-based monolith was successfully applied to the hydrophilic interaction liquid chromatography separation of nucleosides and small peptides, while the methylated ß-CD-functionalized monolith was useful for the separation of nonpolar compounds and drug enantiomers in capillary reversed-phase liquid chromatography. The structures of the monomers were characterized by Fourier transform infrared spectroscopy and mass spectrometry. The physicochemical properties and column performance of monoliths were evaluated by scanning electron microscopy and micro high performance liquid chromatography. This strategy has considerable prospects for the preparation of other derivatized CD-functionalized methacrylate monoliths.

Bipiperidinyl derivatives of 23-hydroxybetulinic acid reverse resistance of HepG2/ADM and MCF-7/ADR cells.

Multidrug resistance (MDR) is a major obstacle to successful chemotherapy for cancer; thus, novel MDR reversers are urgently needed. In the present study, we assessed whether two synthetic derivatives of 23-hydroxybetulinic acid, 3,23-O-diacetyl-17-1,4'-bipiperidinyl betulinic amide (DABB) and 3,23-O-dihydroxy-17-1,4'-bipiperidinyl betulinic amide (DHBB), could reverse MDR induced by ATP-binding cassette (ABC) transporters. Using the MTT assay, we found that DABB and DHBB could enhance the cytotoxicities of ABCB1 substrates doxorubicin, vincristine, and paclitaxel in ABCB1-overexpressing HepG2/ADM and MCF-7/ADR cells, whereas that of a non-ABCB1 substrate cisplatin was unaffected. The ABCB1 substrate accumulation and efflux assay showed that DABB and DHBB not only enhanced the retention of doxorubicin and rhodamine123 but also inhibited the efflux of rhodamine123. Further mechanistic studies by reverse transcription PCR, western blot, and ABCB1 ATPase activity assay indicated that DABB and DHBB suppressed ABCB1 ATPase activity, but did not alter mRNA or protein expression of ABCB1. ABCB1 siRNA pretreatment attenuated the reversal effect of DABB and DHBB, indicating that their reversal effects were partially dependent on ABCB1. Docking analysis also implied that DABB and DHBB bind directly to ABCB1 at a site partly overlapped with that of verapamil. Taken together, our findings suggest that two bipiperidinyl derivatives of 23-hydroxybetulinic acid reverse ABCB1-mediated MDR through modulation of ABCB1 ATPase activity, thereby inhibiting its efflux function in both HepG2/ADM and MCF-7/ADR cells. These findings may contribute toward the development of novel MDR reversers using DABB and DHBB as adjuvant anticancer chemotherapy.

[Study on processing principle of Aconitum pendulum].

OBJECTIVE: To study the processing principles of different processed products of Aconitum pendulum. METHOD: Using high performance liquid chromatography and acute toxicity test to compare the changes in chemical composition and toxicity of the roots and processed products of A. pendulum. RESULT: The main toxic components of the roots of A. pendulum were aconitine, deoxyaconitine and 3-acetylaconitine. The contents of these three alkaloids were significantly reduced in processed products, while benzoylaconitine significantly increased. In addition, processed products emerged aconine, polyschistine-D, beyzoyldeoxyaconine, 16-epi-pyroaconitine and 16-epi-pyrodeoxyaconitine. From the structural analysis, these new emerged compounds transformed from the aconitine, deoxyaconitine and 3-acetylaconitine. CONCLUSION: Different processing methods can reduce the toxicity of the roots of A. pendulum. Processing principle is ester hydrolysis and high-temperature pyrolysis.

[A study of bone-like apatite formation on porous calcium phosphate ceramics in dynamic SBF].

This study aimed at investigating the influence of the flow rate of simulated body fluid (SBF) (2 ml/100 ml.min) of body fluid in skeletal muscle upon the formation of bone-like apatite on porous calcium phosphate ceramics. The in vitro immersion experiment in SBF flowing at normal physiological rate is referred to as dynamic SBF. The results showed that bone-like apatite could only formed in the pores of porous calcium phosphate when SBF flow at physiological rate (2 ml/100 ml.min) of body fluid in skeletal muscle. At the same time, bone-like apatite could form both in the pores and on the surface of the samples if the flowing physiological solution is 1.5 SBF. When the flowing speed of SBF is higher than normal physiological speed (10 ml/100 ml.min), no bone-like apatite could be detected both on the surface and in the pores of the materials. This result is in concordance with animal experiments. The dynamic SBF simulates the biological environment of bone-like apatite formation in body better than static SBF (SBF does not flow). This method is very useful for the research of the mechanism of bonelike apatite formation, which is the key step of bone growth on biomaterials, and can be used as an effective approach to investigate mechanism of the osteoinduction of calcium phosphate in nonosseous tissues in vivo.