Vapor phase polymerization (VPP) is at the forefront for synthesizing high conductivity poly(3,4ethylenedioxythiophene) (PEDOT) as an alternative to indium tin oxide (ITO). Little attention, however, has been directed to the oxidant layer used in the polymerization process. In this study the observation of an oxidant layer (oxidant + PEG-PPG-PEG) possessing liquid-like properties during the vacuum synthesis of PEDOT is reported. This is in contrast to the other oxidant layer variants studied which are observed as solid (pristine oxidant) or gel-like (oxidant + pyridine). Tailoring of the liquid-like properties leads to confluent PEDOT films with a conductivity of 2500 S cm À1 , placing this PEDOT within the conductivity range of commercially available ITO. Building on the liquid-like observation, XPS and ToF-SIMS experiments reveal that PEDOT growth is via a bottom-up mechanism with transportation of new oxidant up to the forming PEDOT layer.

High conductivity poly(3,4-ethylene dioxythiophene) (PEDOT) was synthesised using vacuum vapour phase polymerization (VVPP). The process produces PEDOT composites which incorporate glycol within the polymer. To assess biocompatibility, a suite of analytical techniques were utilised in an effort to characterise the level of glycol present and its impact on cell attachment and proliferation. A small decrease in fibroblast cell attachment and proliferation was observed with increasing glycol content within the PEDOT composite. Keratinocyte cell attachment and proliferation by comparison showed an increase. As such, the results herein indicate that cell attachment and proliferation depends on the individual cell lines used and that the impact of glycol within the PEDOT composite is negligible. This positive outcome prompted investigation of this polymer as a platform for electro-stimulation work. Application of oxidising and reducing potentials to the PEDOT composite were utilised to examine the effect on biocompatibility. Significant effects were seen with altered protein presentation on the reduced surface, and lower mass adsorbed at the oxidised surface. Keratinocytes interacted significantly better on the reduced surface whereas fibroblasts displayed dependence on protein density, with significantly lower spreading on the oxidised surface. Understanding how proteins interact at electrically biased polymer surfaces and in turn affect cell behaviour, underpins the utilisation of such tunable surfaces in biomedical devices. Abstract:High conductivity poly(3,4-ethylene dioxythiophene) (PEDOT) was synthesised using vacuum vapour phase polymerization (VVPP). The process produces PEDOT composites which incorporate glycol within the polymer. To assess biocompatibility, a suite of analytical techniques were utilised in an effort to characterise the level of glycol present and its impact on cell attachment and proliferation. A small decrease in fibroblast cell attachment and proliferation was observed with increasing glycol content within the PEDOT composite. Keratinocyte cell attachment and proliferation by comparison showed an increase. As such, the results herein indicate that cell attachment and proliferation depends on the individual cell lines used and that the impact of glycol within the PEDOT composite is negligible. This positive outcome prompted investigation of this polymer as a platform for electro-stimulation work. Application of oxidising 2 and reducing potentials to the PEDOT composite were utilised to examine the effect on biocompatibility. Significant effects were seen with altered protein presentation on the reduced surface, and lower mass adsorbed at the oxidised surface. Keratinocytes interacted significantly better on the reduced surface whereas fibroblasts displayed dependence on protein density, with significantly lower spreading on the oxidised surface. Understanding how proteins interact at electrically biased polymer surfaces and in turn affect cell behaviour, underpins the utilisation ...

Background: Combination therapy of immune-modulating drugs with modalities targeting tumor cells directly or the tumor stroma are increasing in clinical investigation and practice. In particular, the combination of immune checkpoint modulators targeting PD1 and molecules targeting the tumor stroma, like anti-VEGF therapeutics, are being utilized in multiple permutations and have shown promising results. We have developed a new class of protein therapeutics DARPin® molecules for simultaneous targeting of PD1 and VEGF. The multi-specific PD1 and VEGF targeting molecules were tested for inhibition of PD1 and VEGF mediated functions in cellular functional assays and in syngeneic mouse models. Methods: Inhibition of human PD1 functions were tested in cell binding assays, a reporter cell assay (Promega) and in human primary T-cell assays like mixed lymphocyte reaction (MLR). VEGF-A inhibition was tested in functional assays showing inhibition of VEGFR2 signaling. Molecules targeting murine PD1 were analyzed in cell binding assays and splenocyte assays as well as in syngeneic mouse models. The anti-tumoral-effect was monitored by caliper measurement and on T-cell infiltration and angiogenesis by immunohistochemistry. Results: The multi-specific human PD1-VEGF targeting DARPin® molecule inhibits PD1 mediated downregulation of T-cell receptor signaling in a reporter cell assay in the range of the benchmark antibody Nivolumab. Potent picomolar inhibition of VEGF mediated VEGFR2 signaling was also demonstrated for the molecule. Moreover the molecule showed potent inhibition of PD1 in an MLR assay to a similar level as compared to Nivolumab. A murine surrogate molecule was also produced and showed potent PD1 inhibition in vitro. Syngeneic mouse models demonstrate a strong anti-tumoral effect of the surrogate molecule and an increase in the infiltration of T-cells into the tumor was observed upon treatment. The anti-tumoral effect was strongest by combining the anti-PD1 function with the anti-VEGF function. This indicates that the multi-specific DARPin® molecule is functional, shows potency beyond blocking of only PD1 or VEGF and has a strong potential for therapeutic benefit in the clinic. Conclusions: We have generated a multi-specific PD1 and VEGF targeting DARPin® molecule which is potently active in blocking PD1 and VEGF mediated functions in tumor growth and immunity. The potency of the molecule goes beyond targeting PD1 or VEGF alone and has a strong potential for therapeutic benefit in the clinic. * DARPins are small repeat proteins, designed to bind targets with high affinity and specificity, and which can be combined in a modular fashion to produce multi-functional agents. Citation Format: Jennifer Krieg, Schiegg Dieter, Taylor Joanna, Christel Herzog, Laurent Juglair, Nicolo Rigamonti, Mischa Mueller, Ulrike Fiedler, Michael Tobias Stumpp, Dan Snell. Preclinical characterization of a multi-specific DARPin molecule targeting PD1 and VEGF [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3645. doi:10.1158/1538-7445.AM2017-3645