There is a dialogue between the developing conceptus (embryo-fetus and associated placental membranes) and maternal uterus which must be established during the peri-implantation period for pregnancy recognition sign...There is a dialogue between the developing conceptus (embryo-fetus and associated placental membranes) and maternal uterus which must be established during the peri-implantation period for pregnancy recognition signaling, implantation, regulation of gene expression by uterine epithelial and stromal cells, placentation and exchange of nutrients and gases. The uterus provide a microenvironment in which molecules secreted by uterine epithelia or transported into the uterine lumen represent histotroph required for growth and development of the conceptus and receptivity of the uterus to implantation. Pregnancy recognition signaling mechanisms sustain the functional lifespan of the corpora lutea (CL) which produce progesterone, the hormone of pregnancy essential for uterine functions that support implantation and placentation required for a successful outcome of pregnancy. It is within the peri-implantation period that most embryonic deaths occur due to deficiencies attributed to uterine functions or failure of the conceptus to develop appropriately, signal pregnancy recognition and/or undergo implantation and placentation. With proper placentation, the fetal fluids and fetal membranes each have unique functions to ensure hematotrophic and histotrophic nutrition in support of growth and development of the fetus. The endocrine status of the pregnant female and her nutritional status are critical for successful establishment and maintenance of pregnancy. This review addresses the complexity of key mechanisms that are characteristic of successful reproduction in sheep and pigs and gaps in knowledge that must be the subject of research in order to enhance fertility and reproductive health of livestock species.展开更多
Here, we report that the modification of liposome surfaces with AG73 peptides enhances delivery of the lipophilic anticancer drug, edelfosine, to tumor cells overexpressing the cellsurface receptor, syndecan 2. To tes...Here, we report that the modification of liposome surfaces with AG73 peptides enhances delivery of the lipophilic anticancer drug, edelfosine, to tumor cells overexpressing the cellsurface receptor, syndecan 2. To test the effect of liposomal surface density of AG73 peptides on cellular uptake, we synthesized AG73 peptide-conjugated polyethylene glycol(MW 2000)lipid and incorporated it into fluorescence dye-labeled anionic liposomes with different ligand densities(1, 2, or 5 mol% of total lipids). Cellular uptake of AG73-peptide–modified liposomes gradually increased in proportion to the surface ligand density. The percentages of cells positive for AG73-modified, fluorescent-dye–labeled liposomes were 19.8 ± 2.0%, 23.1 ± 5.0%,and 99.2 ± 1.0%, for ligand mole percentages of 1, 2, and 5, respectively. The cell-targeting ability of AG73-modified liposomes was not significantly altered by the serum content of culture media. In keeping with the observed enhanced cellular uptake, AG73-peptide–modified liposomes entrapping edelfosine exhibited greater cancer cell-killing effects compared with unmodified liposomes. Following intravenous administration into tumor-bearing mice,AG73-peptide–modified liposomes showed 2.1-fold greater accumulation in tumors than unmodified liposomes. These results support the feasibility of using syndecan 2–directed liposomes for delivery of edelfosine.展开更多
Biodegradable stents made of magnesium(Mg)and its alloys have been developed to minimize persistent inflammation or in-stent restenosis,which are the main problems for permanent stents.However,their rapid corrosion be...Biodegradable stents made of magnesium(Mg)and its alloys have been developed to minimize persistent inflammation or in-stent restenosis,which are the main problems for permanent stents.However,their rapid corrosion behavior under physiological conditions leads to poor vascular compatibility and premature structural failure,which remains an important unsolved clinical problem.Herein,we demonstrate a new strategy for solving this problem by combining poly(ether imide)(PEI)coating and subsequent tantalum(Ta)ion implantation.The PEI coating covers the whole surface of the Mg stent uniformly via a spray coating technique and provides Mg with superior corrosion resistance and stable sirolimus-carrying ability.Ta ion implantation is conducted by a sputtering-based plasma immersion ion implantation technique only onto the luminal surface of the PEI-coated Mg stent.Its extremely short processing time(<30 s)permits preservation of the PEI coating’s corrosion protection ability and sirolimus loading characteristics.In addition,a Ta-implanted skin layer that forms on the topmost surface of the PEI coating plays an effective role in not only preventing a rapid release of sirolimus from the surface but also improving the PEI coating’s surface hydrophilicity.Based on in vitro cellular response and blood compatibility tests,Ta ion implantation leads to the improvement of endothelial cell adhesion/proliferation and suppression of platelet adhesion/activation regardless of sirolimus loading.These results indicate that the combination of PEI coating and Ta ion implantation has significant innovative potential to provide excellent vascular compatibility and prevent in-stent restenosis and thrombosis.展开更多
In recent years,pure iron(Fe)has attracted significant attention as a promising biodegradable orthopedic implant material due to its excellent mechanical and biological properties.However,in physiological conditions,F...In recent years,pure iron(Fe)has attracted significant attention as a promising biodegradable orthopedic implant material due to its excellent mechanical and biological properties.However,in physiological conditions,Fe has an extremely slow degradation rate with localized and irregular degradation,which is problematic for practical applications.In this study,we developed a novel combination of a nanostructured surface topography and galvanic reaction to achieve uniform and accelerated degradation of an Fe implant.The target-ion induced plasma sputtering(TIPS)technique was applied on the Fe implant to introduce biologically compatible and electrochemically noble tantalum(Ta)onto its surface and develop surface nano-galvanic couples.Electrochemical tests revealed that the uniformly distributed nano-galvanic corrosion cells of the TIPS-treated sample(nano Ta-Fe)led to relatively uniform and accelerated surface degradation compared to that of bare Fe.Furthermore,the mechanical properties of nano Ta-Fe remained almost constant during a long-term in vitro immersion test(~40 weeks).Biocompatibility was also assessed on surfaces of bare Fe and nano Ta-Fe using in vitro osteoblast responses through direct and indirect contact assays and an in vivo rabbit femur medullary cavity implantation model.The results revealed that nano Ta-Fe not only enhanced cell adhesion and spreading on its surface,but also exhibited no signs of cellular or tissue toxicity.These results demonstrate the immense potential of Ta-implanted surface nanostructures as an effective solution for the practical application of Fe-based orthopedic implants,ensuring long-term biosafety and clinical efficacy.展开更多
Here, we report that chemokine-mimetic plerixafor derivatives could govern tumor-specific delivery and functional effects of nanomaterials. Reduced graphene oxide (rGO) nanosheets were used as a model functional nan...Here, we report that chemokine-mimetic plerixafor derivatives could govern tumor-specific delivery and functional effects of nanomaterials. Reduced graphene oxide (rGO) nanosheets were used as a model functional nanomaterial, and plerixafor-conjugated lipid (PL/rGO) or a benzylcyclam derivative of plerixafor- conjugated lipid (BPL/rGO) was physically adsorbed onto the surface of rGO. The cellular uptake of surface-modified rGO was dependent on overexpression of the CXCR4 chemokine receptor on cancer cells. In KB cells, the binding affinity of BPL/rGO for CXCR4 was 6.8-fold greater than that of PL/rGO. Notably, cellular uptake patterns correlated with in vitro photothermal anticancer efficacy. The tumor distribution of BPL/rGO was higher than that of PL/rGO and plain rGO in mice bearing CXCR4-overexpressing tumors, whereas the distribution of the various rGO forms was similar in mice harboring CXCR4-negative tumors. Moreover, complete photothermal tumor ablation was observed in BPL/rGO- treated mice bearing CXCR4-positive KB cell tumors, but not in CXCR4-negative MCF-7 cell tumors. These results provide evidence that BPL can be used to enhance the delivery of nanomaterials to CXCR4-overexpressing tumors. Chemokine-mimetic BPL can be further applied for nanomaterial-based delivery of photosensitizers, anticancer drugs, or diagnostic tumor imaging agents in CXCR4-overexpressing cancer patients.展开更多
Organic solar cells(OSCs)have reached an outstanding certified power conversion efficiency(PCE)of over 19%in single junction and 20%in tandem architecture design.Such high PCEs have emerged with outstanding Y-shaped Y...Organic solar cells(OSCs)have reached an outstanding certified power conversion efficiency(PCE)of over 19%in single junction and 20%in tandem architecture design.Such high PCEs have emerged with outstanding Y-shaped Y6 non-fullerene acceptors(NFAs),together with PM6 electron donor polymers.PCEs are on the rise for small-area OSCs.However,large-area OSC sub-modules are still unable to achieve such high PCEs,and the highest certified PCE reported so far is∼12%having an area of 58 cm2.To fabricate efficient large-area OSCs,new custom-designed NFAs for large-area systems are imminent along with improvements in the sub-module fabrication platforms.Moreover,the search for stable yet efficient OSCs is still in progress.In this review,progress in small-area OSCs is presented with reference to the advancement in the chemical structure of NFAs and donor polymers.Finally,the life-cycle assessment of OSCs is presented and the energy payback time of the efficient and stable OSCs is discussed and lastly,an outlook for the OSCs is given.展开更多
基金USA-Israel BARD Grant OEP 9604563,USDA Grant 98–01983,NIH Grant HD32534, USDA Grant 00-35203-9137, USDA Grant 98-35203-6322,USDA Grant 2001–02259, USDA grant 2008-35203-19120NIH Grant HD38274 and USA-Israel BARD Grantfunded by the World Class University (WCU) program (R31-10056) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology, Republic of Korea
文摘There is a dialogue between the developing conceptus (embryo-fetus and associated placental membranes) and maternal uterus which must be established during the peri-implantation period for pregnancy recognition signaling, implantation, regulation of gene expression by uterine epithelial and stromal cells, placentation and exchange of nutrients and gases. The uterus provide a microenvironment in which molecules secreted by uterine epithelia or transported into the uterine lumen represent histotroph required for growth and development of the conceptus and receptivity of the uterus to implantation. Pregnancy recognition signaling mechanisms sustain the functional lifespan of the corpora lutea (CL) which produce progesterone, the hormone of pregnancy essential for uterine functions that support implantation and placentation required for a successful outcome of pregnancy. It is within the peri-implantation period that most embryonic deaths occur due to deficiencies attributed to uterine functions or failure of the conceptus to develop appropriately, signal pregnancy recognition and/or undergo implantation and placentation. With proper placentation, the fetal fluids and fetal membranes each have unique functions to ensure hematotrophic and histotrophic nutrition in support of growth and development of the fetus. The endocrine status of the pregnant female and her nutritional status are critical for successful establishment and maintenance of pregnancy. This review addresses the complexity of key mechanisms that are characteristic of successful reproduction in sheep and pigs and gaps in knowledge that must be the subject of research in order to enhance fertility and reproductive health of livestock species.
文摘Here, we report that the modification of liposome surfaces with AG73 peptides enhances delivery of the lipophilic anticancer drug, edelfosine, to tumor cells overexpressing the cellsurface receptor, syndecan 2. To test the effect of liposomal surface density of AG73 peptides on cellular uptake, we synthesized AG73 peptide-conjugated polyethylene glycol(MW 2000)lipid and incorporated it into fluorescence dye-labeled anionic liposomes with different ligand densities(1, 2, or 5 mol% of total lipids). Cellular uptake of AG73-peptide–modified liposomes gradually increased in proportion to the surface ligand density. The percentages of cells positive for AG73-modified, fluorescent-dye–labeled liposomes were 19.8 ± 2.0%, 23.1 ± 5.0%,and 99.2 ± 1.0%, for ligand mole percentages of 1, 2, and 5, respectively. The cell-targeting ability of AG73-modified liposomes was not significantly altered by the serum content of culture media. In keeping with the observed enhanced cellular uptake, AG73-peptide–modified liposomes entrapping edelfosine exhibited greater cancer cell-killing effects compared with unmodified liposomes. Following intravenous administration into tumor-bearing mice,AG73-peptide–modified liposomes showed 2.1-fold greater accumulation in tumors than unmodified liposomes. These results support the feasibility of using syndecan 2–directed liposomes for delivery of edelfosine.
基金supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI)funded by the Ministry of Health&Welfare,Republic of Korea(Grant No:HI18C0493)
文摘Biodegradable stents made of magnesium(Mg)and its alloys have been developed to minimize persistent inflammation or in-stent restenosis,which are the main problems for permanent stents.However,their rapid corrosion behavior under physiological conditions leads to poor vascular compatibility and premature structural failure,which remains an important unsolved clinical problem.Herein,we demonstrate a new strategy for solving this problem by combining poly(ether imide)(PEI)coating and subsequent tantalum(Ta)ion implantation.The PEI coating covers the whole surface of the Mg stent uniformly via a spray coating technique and provides Mg with superior corrosion resistance and stable sirolimus-carrying ability.Ta ion implantation is conducted by a sputtering-based plasma immersion ion implantation technique only onto the luminal surface of the PEI-coated Mg stent.Its extremely short processing time(<30 s)permits preservation of the PEI coating’s corrosion protection ability and sirolimus loading characteristics.In addition,a Ta-implanted skin layer that forms on the topmost surface of the PEI coating plays an effective role in not only preventing a rapid release of sirolimus from the surface but also improving the PEI coating’s surface hydrophilicity.Based on in vitro cellular response and blood compatibility tests,Ta ion implantation leads to the improvement of endothelial cell adhesion/proliferation and suppression of platelet adhesion/activation regardless of sirolimus loading.These results indicate that the combination of PEI coating and Ta ion implantation has significant innovative potential to provide excellent vascular compatibility and prevent in-stent restenosis and thrombosis.
基金This study was supported by the Technology Innovation Program(Material parts package business)(No.20001221,Development of high strength and fatigue resistance metal and manufacturing technology for root analogue dental implants)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘In recent years,pure iron(Fe)has attracted significant attention as a promising biodegradable orthopedic implant material due to its excellent mechanical and biological properties.However,in physiological conditions,Fe has an extremely slow degradation rate with localized and irregular degradation,which is problematic for practical applications.In this study,we developed a novel combination of a nanostructured surface topography and galvanic reaction to achieve uniform and accelerated degradation of an Fe implant.The target-ion induced plasma sputtering(TIPS)technique was applied on the Fe implant to introduce biologically compatible and electrochemically noble tantalum(Ta)onto its surface and develop surface nano-galvanic couples.Electrochemical tests revealed that the uniformly distributed nano-galvanic corrosion cells of the TIPS-treated sample(nano Ta-Fe)led to relatively uniform and accelerated surface degradation compared to that of bare Fe.Furthermore,the mechanical properties of nano Ta-Fe remained almost constant during a long-term in vitro immersion test(~40 weeks).Biocompatibility was also assessed on surfaces of bare Fe and nano Ta-Fe using in vitro osteoblast responses through direct and indirect contact assays and an in vivo rabbit femur medullary cavity implantation model.The results revealed that nano Ta-Fe not only enhanced cell adhesion and spreading on its surface,but also exhibited no signs of cellular or tissue toxicity.These results demonstrate the immense potential of Ta-implanted surface nanostructures as an effective solution for the practical application of Fe-based orthopedic implants,ensuring long-term biosafety and clinical efficacy.
文摘Here, we report that chemokine-mimetic plerixafor derivatives could govern tumor-specific delivery and functional effects of nanomaterials. Reduced graphene oxide (rGO) nanosheets were used as a model functional nanomaterial, and plerixafor-conjugated lipid (PL/rGO) or a benzylcyclam derivative of plerixafor- conjugated lipid (BPL/rGO) was physically adsorbed onto the surface of rGO. The cellular uptake of surface-modified rGO was dependent on overexpression of the CXCR4 chemokine receptor on cancer cells. In KB cells, the binding affinity of BPL/rGO for CXCR4 was 6.8-fold greater than that of PL/rGO. Notably, cellular uptake patterns correlated with in vitro photothermal anticancer efficacy. The tumor distribution of BPL/rGO was higher than that of PL/rGO and plain rGO in mice bearing CXCR4-overexpressing tumors, whereas the distribution of the various rGO forms was similar in mice harboring CXCR4-negative tumors. Moreover, complete photothermal tumor ablation was observed in BPL/rGO- treated mice bearing CXCR4-positive KB cell tumors, but not in CXCR4-negative MCF-7 cell tumors. These results provide evidence that BPL can be used to enhance the delivery of nanomaterials to CXCR4-overexpressing tumors. Chemokine-mimetic BPL can be further applied for nanomaterial-based delivery of photosensitizers, anticancer drugs, or diagnostic tumor imaging agents in CXCR4-overexpressing cancer patients.
基金the National Research Foundation of Korea(NRF)Grant funded by the Korea government(MSIT)(Grant No.2021R1A2C3008724).
文摘Organic solar cells(OSCs)have reached an outstanding certified power conversion efficiency(PCE)of over 19%in single junction and 20%in tandem architecture design.Such high PCEs have emerged with outstanding Y-shaped Y6 non-fullerene acceptors(NFAs),together with PM6 electron donor polymers.PCEs are on the rise for small-area OSCs.However,large-area OSC sub-modules are still unable to achieve such high PCEs,and the highest certified PCE reported so far is∼12%having an area of 58 cm2.To fabricate efficient large-area OSCs,new custom-designed NFAs for large-area systems are imminent along with improvements in the sub-module fabrication platforms.Moreover,the search for stable yet efficient OSCs is still in progress.In this review,progress in small-area OSCs is presented with reference to the advancement in the chemical structure of NFAs and donor polymers.Finally,the life-cycle assessment of OSCs is presented and the energy payback time of the efficient and stable OSCs is discussed and lastly,an outlook for the OSCs is given.