TY  - JOUR
A1  - Krüger-Genge, A.
A1  - Braune, S.
A1  - Walter, M.
A1  - Krengel, M.
A1  - Kratz, K.
A1  - Küpper, J. H.
A1  - Lendlein, Andreas
A1  - Jung, Friedrich
T1  - Influence of different surface treatments of poly(n-butyl acrylate) networks on fibroblasts adhesion, morphology and viability
JF  - Clinical hemorheology and microcirculation : blood flow and vessels
N2  - BACKGROUND: Physical and chemical characteristics of implant materials determine the fate of long-term cardiovascular devices. However, there is still a lack of fundamental understanding of the molecular mechanisms occurring in the material-tissue interphase. In a previous study, soft covalently crosslinked poly(n-butyl acrylate) networks (cPnBA) were introduced as sterilizable, non-toxic and immuno-compatible biomaterials with mechanical properties adjustable to blood vessels. Here we study the influence of different surface treatments in particular oxygen plasma modification and fibrinogen deposition as well as a combinatorial approach on the adhesion and viability of fibroblasts. RESULTS: Compared to non-treated cPnBAs the advancing water-contact angles were found to be reduced after all surface modifications (p<0.05, each), while lowest values were observed after the combined surface treatment (OPT+FIB). The latter differed significantly from the single OPT and FIB. The number of adherent fibroblasts and their adherence behavior differed on both pristine cPnBA networks. The fibroblast density on cPnBA04 was 743 +/- 434 cells. mm(-2), was about 6.5 times higher than on cPnBA73 with 115 +/- 73 cells. mm(-2). On cPnBA04 about 20% of the cells were visible as very small, round and buckled cells while all other cells were in a migrating status. On cPnBA73, nearly 50% of fibroblasts were visible as very small, round and buckled cells. The surface functionalization either using oxygen plasma treatment or fibrinogen coating led to a significant increase of adherent fibroblasts, particularly the combination of both techniques, for both cPnBA networks. It is noteworthy to mention that the fibrinogen coating overruled the characteristics of the pristine surfaces; here, the fibroblast densities after seeding were identical for both cPnBAnetworks. Thus, the binding rather depended on the fibrinogen coating than on the substrate characteristics anymore. While the integrity of the fibroblasts membrane was comparable for both polymers, the MTS tests showed a decreased metabolic activity of the fibroblasts on cPnBA. CONCLUSION: The applied surface treatments of cPnBA successfully improved the adhesion of viable fibroblasts. Under resting conditions as well as after shearing the highest fibroblast densities were found on surfaces with combined post-treatment.
KW  - Biomaterial
KW  - poly(n-butyl acrylate)
KW  - fibroblast
KW  - oxygen plasma
KW  - fibrinogen
KW  - cell adhesion
KW  - focal adhesion
KW  - actin cytoskeleton
KW  - viability
Y1  - 2018
U6  - https://doi.org/10.3233/CH-189130
SN  - 1386-0291
SN  - 1875-8622
VL  - 69
IS  - 1-2
SP  - 305
EP  - 316
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Zhang, Shanshan
A1  - Stolterfoht, Martin
A1  - Armin, Ardalan
A1  - Lin, Qianqian
A1  - Zu, Fengshuo
A1  - Sobus, Jan
A1  - Jin, Hui
A1  - Koch, Norbert
A1  - Meredith, Paul
A1  - Burn, Paul L.
A1  - Neher, Dieter
T1  - Interface Engineering of Solution-Processed Hybrid Organohalide Perovskite Solar Cells
JF  - ACS applied materials & interfaces
N2  - Engineering the interface between the perovskite absorber and the charge-transporting layers has become an important method for improving the charge extraction and open-circuit voltage (V-OC) of hybrid perovskite solar cells. Conjugated polymers are particularly suited to form the hole-transporting layer, but their hydrophobicity renders it difficult to solution-process the perovskite absorber on top. Herein, oxygen plasma treatment is introduced as a simple means to change the surface energy and work function of hydrophobic polymer interlayers for use as p-contacts in perovskite solar cells. We find that upon oxygen plasma treatment, the hydrophobic surfaces of different prototypical p-type polymers became sufficiently hydrophilic to enable subsequent perovskite junction processing. In addition, the oxygen plasma treatment also increased the ionization potential of the polymer such that it became closer to the valance band energy of the perovskite. It was also found that the oxygen plasma treatment could increase the electrical conductivity of the p-type polymers, facilitating more efficient charge extraction. On the basis of this concept, inverted MAPbI(3) perovskite devices with different oxygen plasma-treated polymers such as P3HT, P3OT, polyTPD, or PTAA were fabricated with power conversion efficiencies of up to 19%.
KW  - organohalide lead perovskites
KW  - solar cells
KW  - surface wetting
KW  - work function
KW  - oxygen plasma
KW  - transport layer
Y1  - 2018
U6  - https://doi.org/10.1021/acsami.8b02503
SN  - 1944-8244
VL  - 10
IS  - 25
SP  - 21681
EP  - 21687
PB  - American Chemical Society
CY  - Washington
ER  -