TY  - JOUR
A1  - Tetali, Sarada D.
A1  - Jankowski, Vera
A1  - Luetzow, Karola
A1  - Kratz, Karl
A1  - Lendlein, Andreas
A1  - Jankowski, Joachim
T1  - Adsorption capacity of poly(ether imide) microparticles to uremic toxins
JF  - Clinical hemorheology and microcirculation : blood flow and vessels
N2  - Uremia is a phenomenon caused by retention of uremic toxins in the plasma due to functional impairment of kidneys in the elimination of urinary waste products. Uremia is presently treated by dialysis techniques like hemofiltration, dialysis or hemodiafiltration. However, these techniques in use are more favorable towards removing hydrophilic than hydrophobic uremic toxins. Hydrophobic uremic toxins, such as hydroxy hipuric acid (OH-HPA), phenylacetic acid (PAA), indoxyl sulfate (IDS) and p-cresylsulfate (pCRS), contribute substantially to the progression of chronic kidney disease (CKD) and cardiovascular disease. Therefore, objective of the present study is to test adsorption capacity of highly porous microparticles prepared from poly(ether imide) (PEI) as an alternative technique for the removal of uremic toxins. Two types of nanoporous, spherically shaped microparticles were prepared from PEI by a spraying/coagulation process. PEI particles were packed into a preparative HPLC column to which a mixture of the four types of uremic toxins was injected and eluted with ethanol. Eluted toxins were quantified by analytical HPLC. PEI particles were able to adsorb all four toxins, with the highest affinity for PAA and pCR. IDS and OH-HPA showed a partially non-reversible binding. In summary, PEI particles are interesting candidates to be explored for future application in CKD.
KW  - Adsorption of uremic toxins
KW  - chronic kidney disease (CKD)
KW  - hydrophobic uremic toxins
KW  - poly(ether imide)
KW  - microparticles
KW  - uremia
Y1  - 2016
U6  - https://doi.org/10.3233/CH-152026
SN  - 1386-0291
SN  - 1875-8622
VL  - 61
SP  - 657
EP  - 665
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kumar, Reddi K.
A1  - Basu, Sayantani
A1  - Lemke, Horst-Dieter
A1  - Jankowski, Joachim
A1  - Kratz, Karl
A1  - Lendlein, Andreas
A1  - Tetali, Sarada D.
T1  - Effect of extracts of poly(ether imide) microparticles on cytotoxicity, ROS generation and proinflammatory effects on human monocytic (THP-1) cells
JF  - Clinical hemorheology and microcirculation : blood flow and vessels
N2  - A high cell viability of around 99 +/- 18% and 99 +/- 5% was observed when THP-1 cells were cultured in the presence of aqueous extracts of the PEI microparticles in medium A and medium B respectively. The obtained microscopic data suggested that PEI particle extracts have no significant effect on cell death, oxidative stress or differentiation to macrophages. It was further found that the investigated proinflammatory markers in THP-1 cells were not up-regulated. These results are promising with regard to the biocompatibility of PEI microparticles and in a next step the hemocompatibility of the microparticles will be examined.
KW  - Chronic kidney disease (CKD)
KW  - cytotoxicity
KW  - human monocytic (THP-1) cells
KW  - poly(ether imide) microparticles
KW  - reactive oxygen species (ROS)
Y1  - 2016
U6  - https://doi.org/10.3233/CH-152027
SN  - 1386-0291
SN  - 1875-8622
VL  - 61
SP  - 667
EP  - 680
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Kumar, Reddi K.
A1  - Heuchel, Matthias
A1  - Kratz, Karl
A1  - Lendlein, Andreas
A1  - Jankowski, Joachim
A1  - Tetali, Sarada D.
T1  - Effects of extracts prepared from modified porous poly(ether imide) microparticulate absorbers on cytotoxicity, macrophage differentiation and proinflammatory behavior of human monocytic (THP-1) cells
JF  - Clinical hemorheology and microcirculation : blood flow and vessels
N2  - Remaining uremic toxins in the blood of chronic renal failure patients represent one central challenge in hemodialysis therapies. Highly porous poly(ether imide) (PEI) microparticles have been recently introduced as candidate absorber materials, which show a high absorption capacity for uremic toxins and allow hydrophilic surface modification suitable for minimization of serum protein absorption. In this work, the effects of extracts prepared from PEI microparticles modified by nucleophilic reaction with low molecular weight polyethylene imine (Pei) or potassium hydroxide (KOH), on human monocytic (THP-1) cells are studied. The obtained results suggested that the extracts of Pei and KOH modified PEI absorbers have no negative effect on THP-1 cell viability and do not initiate the critical differentiation towards macrophages. The extracts did not enhance transcript or protein levels of investigated proinflammatory markers in THP-1 cells, namely, TNF alpha, MCP1, IL6 and IL8. Based on these findings such modified PEI microparticles should be qualified for further pre-clinical evaluation i.e. in an in vivo animal experiment.
KW  - Chronic kidney disease
KW  - hemodialysis
KW  - Inflammation
KW  - Porous poly(ether imide) microparticulate absorbers
KW  - THP-1 cells
KW  - Uremic toxins
Y1  - 2018
U6  - https://doi.org/10.3233/CH-189112
SN  - 1386-0291
SN  - 1875-8622
VL  - 69
IS  - 1-2
SP  - 175
EP  - 185
PB  - IOS Press
CY  - Amsterdam
ER  -