TY  - JOUR
A1  - Spenst, Peter
A1  - Young, Ryan M.
A1  - Wasielewski, Michael R.
A1  - Würthner, Frank
T1  - Guest and solvent modulated photo-driven charge separation and triplet generation in a perylene bisimide cyclophane
JF  - Chemical Science
N2  - Cofacial positioning of two perylene bisimide (PBI) chromophores at a distance of 6.5 angstrom in a cyclophane structure prohibits the otherwise common excimer formation and directs photoexcited singlet state relaxation towards intramolecular symmetry-breaking charge separation (τ\(_{CS}\) = 161 +/- 4 ps) in polar CH\(_2\)Cl\(_2\), which is thermodynamically favored with a Gibbs free energy of ΔG\(_{CS}\) = -0.32 eV. The charges then recombine slowly in τ\(_{CR}\) = 8.90 +/- 0.06 ns to form the PBI triplet excited state, which can be used subsequently to generate singlet oxygen in 27% quantum yield. This sequence of events is eliminated by dissolving the PBI cyclophane in non-polar toluene, where only excited singlet state decay occurs. In contrast, complexation of electron-rich aromatic hydrocarbons by the host PBI cyclophane followed by photoexcitation of PBI results in ultrafast electron transfer (<10 ps) from the guest to the PBI in CH\(_2\)Cl\(_2\). The rate constants for charge separation and recombination increase as the guest molecules become easier to oxidize, demonstrating that charge separation occurs close to the peak of the Marcus curve and the recombination lies far into the Marcus inverted region.
KW  - photoinduced electron transfer
KW  - Marcus inverted region
KW  - cyclic perylene bisimide
KW  - PBI cyclophane
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191252
VL  - 7
IS  - 8
ER  - 
TY  - JOUR
A1  - Burns, Alan J.
A1  - Goldstein, Allan M.
A1  - Newgreen, Donald F.
A1  - Stamp, Lincon
A1  - Schäfer, Karl-Herbert
A1  - Metzger, Marco
A1  - Hotta, Ryo
A1  - Young, Heather M.
A1  - Andrews, Peter W.
A1  - Thapar, Nikhil
A1  - Belkind-Gerson, Jaime
A1  - Bondurand, Nadege
A1  - Bornstein, Joel C.
A1  - Chan, Wood Yee
A1  - Cheah, Kathryn
A1  - Gershon, Michael D.
A1  - Heuckeroth, Robert O.
A1  - Hofstra, Robert M.W.
A1  - Just, Lothar
A1  - Kapur, Raj P.
A1  - King, Sebastian K.
A1  - McCann, Conor J.
A1  - Nagy, Nandor
A1  - Ngan, Elly
A1  - Obermayr, Florian
A1  - Pachnis, Vassilis
A1  - Pasricha, Pankaj J.
A1  - Sham, Mai Har
A1  - Tam, Paul
A1  - Vanden Berghe, Pieter
T1  - White paper on guidelines concerning enteric nervous system stem cell therapy for enteric neuropathies
JF  - Developmental Biology
N2  - Over the last 20 years, there has been increasing focus on the development of novel stem cell based therapies for the treatment of disorders and diseases affecting the enteric nervous system (ENS) of the gastrointestinal tract (so-called enteric neuropathies). Here, the idea is that ENS progenitor/stem cells could be transplanted into the gut wall to replace the damaged or absent neurons and glia of the ENS. This White Paper sets out experts' views on the commonly used methods and approaches to identify, isolate, purify, expand and optimize ENS stem cells, transplant them into the bowel, and assess transplant success, including restoration of gut function. We also highlight obstacles that must be overcome in order to progress from successful preclinical studies in animal models to ENS stem cell therapies in the clinic.
KW  - Neural crest cells
KW  - Rat mynteric plexus
KW  - Intestinal pseudoobstruction
KW  - Hypertrophic pyloric-stenosis
KW  - Hirschsprung disease liability
KW  - Slow-transit constipation
KW  - Oxide synthase gene
KW  - Term follow-up
KW  - Nitric-oxide
KW  - In-vivo
KW  - Enteric nervous system
KW  - Enteric neuropathies
KW  - Stem cells
KW  - Cell replacement therapy
KW  - Hirschsprung disease
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-187415
VL  - 417
IS  - 2
ER  -