@article{BhaskarMaLendleinetal.2015, author = {Bhaskar, Thanga Bhuvanesh Vijaya and Ma, Nan and Lendlein, Andreas and Roch, Toralf}, title = {The interaction of human macrophage subsets with silicone as a biomaterial}, series = {Clinical hemorheology and microcirculation : blood flow and vessels}, volume = {61}, journal = {Clinical hemorheology and microcirculation : blood flow and vessels}, number = {2}, publisher = {IOS Press}, address = {Amsterdam}, issn = {1386-0291}, doi = {10.3233/CH-151991}, pages = {119 -- 133}, year = {2015}, abstract = {Silicones are widely used as biomaterials for medical devices such as extracorporeal equipments. However, there is often conflicting evidence about their supposed cell-and histocompatibility. Macrophages could mediate silicone-induced adverse responses such as foreign body reaction and fibrous encapsulation. The polarization behaviour of macrophages could determine the clinical outcome after implantation of biomaterials. Induction of classically activated macrophages (CAM) may induce and support uncontrolled inflammatory responses and undesired material degradation. In contrast, polarization into alternatively activated macrophages (AAM) is assumed to support healing processes and implant integration. This study compared the interaction of non-polarized macrophages (M0), CAM, and AAM with commercially available tissue culture polystyrene (TCP) and a medical grade silicone-based biomaterial, regarding the secretion of inflammatory mediators such as cytokines and chemokines. Firstly, by using the Limulus amoebocyte lysate (LAL) test the silicone films were shown to be free of soluble endotoxins, which is the prerequisite to investigate their interaction with primary immune cells. Primary human monocyte-derived macrophages (M0) were polarized into CAM and AAM by addition of suitable differentiation factors. These macrophage subsets were incubated on the materials for 24 hours and their viability and cytokine secretion was assessed. In comparison to TCP, cell adhesion was lower on silicone after 24 hours for all three macrophage subsets. However, compared to TCP, silicone induced higher levels of certain inflammatory and chemotactic cytokines in M0, CAM, and AAM macrophage subsets. Conclusively, it was shown that silicone has the ability to induce a pro-inflammatory state to different magnitudes dependent on the macrophage subsets. This priming of the macrophage phenotype by silicone could explain the incidence of severe foreign body complications observed in vivo.}, language = {en} } @article{RochKratzMaetal.2015, author = {Roch, Toralf and Kratz, Karl and Ma, Nan and Lendlein, Andreas}, title = {Polymeric inserts differing in their chemical composition as substrates for dendritic cell cultivation}, series = {Clinical hemorheology and microcirculation : blood flow and vessels}, volume = {61}, journal = {Clinical hemorheology and microcirculation : blood flow and vessels}, number = {2}, publisher = {IOS Press}, address = {Amsterdam}, issn = {1386-0291}, doi = {10.3233/CH-152004}, pages = {347 -- 357}, year = {2015}, abstract = {Dendritic cells (DC) contribute to immunity by presenting antigens to T cells and shape the immune response by the secretion of cytokines. Due to their immune stimulatory potential DC-based therapies are promising approaches to overcome tolerance e.g. against tumors. In order to enforce the immunogenicity of DCs, they have to be matured and activated in vitro, which requires an appropriate cell culture substrate, supporting their survival expansion and activation. Since most cell culture devices are not optimized for DC growth, it is hypothesized that polymers with certain physicochemical properties can positively influence the DC cultures. With the aim to evaluate the effects that polymers with different chemical compositions have on the survival, the activation status, and the cytokine/chemokine secretion profile of DC, their interaction with polystyrene (PS), polycarbonate (PC), poly(ether imide) (PEI), and poly(styrene-co-acrylonitrile) (PSAN)-based cell culture inserts was investigated. By using this insert system, which fits exactly into 24 well cell culture plates, effects induced from the culture dish material can be excluded. The viability of untreated DC after incubation with the different inserts was not influenced by the different inserts, whereas LPS-activatedDCshowed an increased survival after cultivation on PC, PS, and PSAN compared to tissue culture polystyrene (TCP). The activation status of DC estimated by the expression of CD40, CD80, CD83, CD86 and HLA-DR expression was not altered by the different inserts in untreated DC but slightly reduced when LPS-activated DC were cultivated on PC, PS, PSAN, and PEI compared to TCP. For each polymeric cell culture insert a distinct cytokine profile could be observed. Since inserts with different chemical compositions of the inserts did not substantially alter the behavior of DC all insert systems could be considered as alternative substrate. The observed increased survival on some polymers, which showed in contrast to TCP a hydrophobic surface, could be beneficial for certain applications such as T cell expansion and activation.}, language = {en} } @article{WangKratzBehletal.2015, author = {Wang, Weiwei and Kratz, Karl and Behl, Marc and Yan, Wan and Liu, Yue and Xu, Xun and Baudis, Stefan and Li, Zhengdong and Kurtz, Andreas and Lendlein, Andreas and Ma, Nan}, title = {The interaction of adipose-derived human mesenchymal stem cells and polyether ether ketone}, series = {Clinical hemorheology and microcirculation : blood flow and vessels}, volume = {61}, journal = {Clinical hemorheology and microcirculation : blood flow and vessels}, number = {2}, publisher = {IOS Press}, address = {Amsterdam}, issn = {1386-0291}, doi = {10.3233/CH-152001}, pages = {301 -- 321}, year = {2015}, abstract = {Polyether ether ketone (PEEK) as a high-performance, thermoplastic implant material entered the field of medical applications due to its structural function and commercial availability. In bone tissue engineering, the combination of mesenchymal stem cells (MSCs) with PEEK implants may accelerate the bone formation and promote the osseointegration between the implant and the adjacent bone tissue. In this concept the question how PEEK influences the behaviour and functions of MSCs is of great interest. Here the cellular response of human adipose-derived MSCs to PEEK was evaluated and compared to tissue culture plate (TCP) as the reference material. Viability and morphology of cells were not altered when cultured on the PEEK film. The cells on PEEK presented a high proliferation activity in spite of a relatively lower initial cell adhesion rate. There was no significant difference on cell apoptosis and senescence between the cells on PEEK and TCP. The inflammatory cytokines and VEGF secreted by the cells on these two surfaces were at similar levels. The cells on PEEK showed up-regulated BMP2 and down-regulated BMP4 and BMP6 gene expression, whereas no conspicuous differences were observed in the committed osteoblast markers (BGLAP, COL1A1 and Runx2). With osteoinduction the cells on PEEK and TCP exhibited a similar osteogenic differentiation potential. Our results demonstrate the biofunctionality of PEEK for human MSC cultivation and differentiation. Its clinical benefits in bone tissue engineering may be achieved by combining MSCs with PEEK implants. These data may also provide useful information for further modification of PEEK with chemical or physical methods to regulate the cellular processes of MSCs and to consequently improve the efficacy of MSC-PEEK based therapies.}, language = {en} }