Tissue (re)vascularization strategies face various challenges, as therapeutic cells do not survive long enough in situ, while the administration of pro-angiogenic factors is hampered by fast clearance and insufficient...Tissue (re)vascularization strategies face various challenges, as therapeutic cells do not survive long enough in situ, while the administration of pro-angiogenic factors is hampered by fast clearance and insufficient ability to emulate complex spatiotemporal signaling. Here, we propose to address these limitations by engineering a functional biomaterial capable of capturing and concentrating the pro-angiogenic activities of mesenchymal stem cells (MSCs). In particular, dextran sulfate, a high molecular weight sulfated glucose polymer, supplemented to MSC cul-tures, interacts with MSC-derived extracellular matrix (ECM) components and facilitates their co-assembly and accumulation in the pericellular space. Upon decellularization, the resulting dextran sulfate-ECM hybrid material can be processed into MIcroparticles of SOlidified Secretome (MIPSOS). The insoluble format of MIPSOS protects protein components from degradation, while facilitating their sustained release. Proteomic analysis demonstrates that MIPSOS are highly enriched in pro-angiogenic factors, resulting in an enhanced pro-angiogenic bioactivity when compared to naïve MSC-derived ECM (cECM). Consequently, intravital microscopy of full-thickness skin wounds treated with MIPSOS demonstrates accelerated revascularization and healing, far superior to the ther-apeutic potential of cECM. Hence, the microparticle-based solidified stem cell secretome provides a promising platform to address major limitations of current therapeutic angiogenesis approaches.展开更多
We have fabricated a new perylene bisimide(PBI)folda-dimer(BPBI-CB-1)by tethering two PBI moieties to the ortho-carbon positions of a carborane unit.The synthesized compound adopted distinct configurations in differen...We have fabricated a new perylene bisimide(PBI)folda-dimer(BPBI-CB-1)by tethering two PBI moieties to the ortho-carbon positions of a carborane unit.The synthesized compound adopted distinct configurations in different solvents with dual emissions as its characteristic.The two PBI moieties in the molecule appeared either in a weakly interacted,monomer-like state or brought into close π-π contact with each other,forming an interacted stacking state.The equilibrium between these two states was governed by the nature of solvents and testing temperature.Spectroscopic and theoretical studies concluded that dual emission bands originated from intramolecular monomer-like and stacking states,respectively.Remarkably,in a solvent like 1,2-dichloroethane(DCE),both emission intensities increased with rising temperatures.The positive temperature response of the monomer emission was ascribed to an increased amount of monomer-like population,owing to its endothermic energy state,while the excimer emission was rationalized by increased population of the bright exciton state,resulting in an increased emission yield that compensated the diminished population of the stacking state.To our knowledge,this is the first report on positive temperature-responsive dual emissions associated with the synergism of intramolecular intersubunit aggregation/dissociation and excimer transformation.展开更多
基金Funding support for material synthesis and in vitro work includes a laboratory start-up grant(8508266)from CUHK(AB),a direct grant(2019.016)from the Faculty of Medicine,CUHK(AB)and a grant from the Shun Hing Institute of Advanced Engineering(SHIAE,BME-p5-20,AB)Hong Kong SAR China.R.S.T.would like to acknowledge the Lee Quo Wei and Lee Yick Hoi Lun Professorship in Tissue Engineering and Regenerative Medicine(RST).J.G.and G.G.acknowledge financial support from the National Natural Science Foundation of China(J.G.,No.22178233)+1 种基金the National Global Talents Recruitment Program,the Talents Program of Sichuan Province,State Key Laboratory of Polymer Materials Engineering(Grant No.sklpme 2020-3-01)Key Laboratory of Leather Chemistry and En-gineering,and the National Engineering Research Center of Clean Technology in Leather Industry.The experimental data analyzed by Orbitrap Fusion mass spectrometer were acquired at the Academia Sinica Common Mass Spectrometry Facilities for Proteomics and Protein Modification Analysis located at the Institute of Biological Chemistry,Academia Sinica,supported by Academia Sinica Core Facility and Innovative Instrument Project Grant(AS-CFII-108-107).
文摘Tissue (re)vascularization strategies face various challenges, as therapeutic cells do not survive long enough in situ, while the administration of pro-angiogenic factors is hampered by fast clearance and insufficient ability to emulate complex spatiotemporal signaling. Here, we propose to address these limitations by engineering a functional biomaterial capable of capturing and concentrating the pro-angiogenic activities of mesenchymal stem cells (MSCs). In particular, dextran sulfate, a high molecular weight sulfated glucose polymer, supplemented to MSC cul-tures, interacts with MSC-derived extracellular matrix (ECM) components and facilitates their co-assembly and accumulation in the pericellular space. Upon decellularization, the resulting dextran sulfate-ECM hybrid material can be processed into MIcroparticles of SOlidified Secretome (MIPSOS). The insoluble format of MIPSOS protects protein components from degradation, while facilitating their sustained release. Proteomic analysis demonstrates that MIPSOS are highly enriched in pro-angiogenic factors, resulting in an enhanced pro-angiogenic bioactivity when compared to naïve MSC-derived ECM (cECM). Consequently, intravital microscopy of full-thickness skin wounds treated with MIPSOS demonstrates accelerated revascularization and healing, far superior to the ther-apeutic potential of cECM. Hence, the microparticle-based solidified stem cell secretome provides a promising platform to address major limitations of current therapeutic angiogenesis approaches.
基金the Natural Science Foundation of China(nos.21820102005,21527802,and 21673133)China 111 project(no.B14041)Program for Changjiang Scholars and Innovative Research Team in University(no.IRT-14R33).
文摘We have fabricated a new perylene bisimide(PBI)folda-dimer(BPBI-CB-1)by tethering two PBI moieties to the ortho-carbon positions of a carborane unit.The synthesized compound adopted distinct configurations in different solvents with dual emissions as its characteristic.The two PBI moieties in the molecule appeared either in a weakly interacted,monomer-like state or brought into close π-π contact with each other,forming an interacted stacking state.The equilibrium between these two states was governed by the nature of solvents and testing temperature.Spectroscopic and theoretical studies concluded that dual emission bands originated from intramolecular monomer-like and stacking states,respectively.Remarkably,in a solvent like 1,2-dichloroethane(DCE),both emission intensities increased with rising temperatures.The positive temperature response of the monomer emission was ascribed to an increased amount of monomer-like population,owing to its endothermic energy state,while the excimer emission was rationalized by increased population of the bright exciton state,resulting in an increased emission yield that compensated the diminished population of the stacking state.To our knowledge,this is the first report on positive temperature-responsive dual emissions associated with the synergism of intramolecular intersubunit aggregation/dissociation and excimer transformation.
