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Vapor-phase deposited polymer coatings are applied on thin indomethacin films to modify the drug release. Hydrogel-forming co-polymers of 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate were prepared directly on top of solution cast indomethacin thin films by initiated Chemical Vapor Deposition (iCVD). This technique allows for solvent-free processing under mild conditions, thus minimizing a potential impact on the pharmaceutical. The drug release behavior, among other properties, was evaluated for polymers of different compositions and at different temperatures. The data show that the release kinetics can be tuned by several orders of magnitude as the cross-linker fraction is varied in the polymer coating. While uncoated indomethacin films were fully released within an hour, polymer coatings showed gradual liberation over several hours to days. Additional insight is gained from evaluating the experimental dissolution data in the framework of diffusive transport. The results of this study show that the iCVD technique has some promises for pharmaceutical technology, potentially allowing for tailored release behavior also for other drug systems.

Nature's most brilliant hues arise from the interaction of light with multilayered‐ structures of aligned building blocks. Mimicking this hierarchical organization in highly‐ordered thin films of liquid crystalline species has attracted increasing attention for potential applications in sensors and optical switching displays. Due to its intriguing ability to organize into optically active materials, cellulose nanocrystals (CNCs) are attracting a strong interest in the scientific community. This study demonstrates that the shear‐driven convective assembly technique can be used to stratify in a controlled fashion highly ordered multilayers of rod‐like CNC embedded in a protective hydrophobic polymer matrix leading to optically active thin films. The films remain fully transparent even after stratifying 50 layers. Atomic force microscopy analysis reveals that over 87% of the CNCs in the upper layer aligned within ±20° of the withdrawal direction. Notably, the stratification does not disrupt the organization of the underlying layers. The films exhibit strong selective reflections with uniform and intense colors, dependent on the number of stratified layers. This scalable appraoch enables precise control over the optical characteristics of CNC‐polymer composite films, presenting opportunities for environmentally friendly applications in pigment‐free coatings, security papers, and optical devices. Explore shear‐driven convective assembly's role in creating optically active thin films. Highly ordered multilayers of cellulose nanocrystals (CNCs) in a hydrophobic polymer matrix are achieved, offering precise control. The resulting films' optical activity, modulated by layer count, presents possibilities for pigment‐free coatings, security papers, and optical devices in this scalable, green technology.

ABSTRACT Purpose The low aqueous solubility of many drugs impedes detailed investigation as the detection limit of standard testing routines is limited. This is further complicated within application relevant thin films typical used in patches or stripes for buccal or topical routes. Methods In this work a model system is developed based on spin – casting technique allowing defined clotrimazole and clotrimazole – polystyrene composite films preparation at a solid surface. Various highly sensitive techniques including quarz crystal microbalance (QCM), X-ray reflevtivity (XRR) and X-ray photon spectroscopy (XPS) are used to investigate the drug release over time into an aqueous media. Results The results reveal a steady drug release for both samples over the course of the experiments but with the release from the composite being significantly slower. In addition the dissolution rate of the clotrimazole sample initially increases up to 30 min after which a decrease is noted. XRR shows that this is a result of surface roughening together with film thickness reduction. The results for the composite show that the release in the composite film is a result of drug diffusion within the matrix and collapsing PS film thickness whereby XPS shows that the amount of clotrimazole at the surface after 800 min immersion is still high. Conclusion It can be stated that the applied techniques allow following low mass drug release in detail which may also be applied to other systems like pellets or surface loaded nano-carriers providing information for processing and application relevant parameters.

Herein, we report the synthesis of a novel, tetrazine-based conjugated polymer. Tetrazines have the benefit of being strong electron acceptors, while little steric hindrance is imposed on the flanking thiophene rings. Conversion of a suitably substituted nitrile precursor led to 3,6-bis(5-bromo-4-(2-octyldodecyl)thiophen-2-yl)-1,2,4,5-tetrazine (2OD-TTz). Palladium-catalyzed copolymerization of 2OD-TTz with a bithiophene monomer yielded an alternating tetrazine–quaterthiophene copolymer (PTz4T-2OD). The polymer PTz4T-2OD showed an optical band gap of 1.8 eV, a deep HOMO energy level of − 5.58 eV and good solubility. In combination with the non-fullerene acceptor ITIC-F, solar cells with power conversion efficiencies of up to 2.6% were obtained.

Cellulose Nanocrystals The cover page illustrates cellulose nanocrystals extracted from trees, symbolizing nature's contribution to advanced materials. These nanocrystals align to form stratified thin films of varying thickness, each displaying vibrant, tunable colors. The artwork visually conveys the study's focus on environmentally friendly, optically active coatings, emphasizing the elegance and scalability of cellulose‐based materials for innovative applications. More details can be found in article 2400608 by Youssef Habibi and co‐workers.

In polymer processing, solvent and melt intercalations compete in cost-to-property improvements. In this study, melt intercalation and solution blending methods are investigated for manufacturing graphene/polyolefin nanocomposites. Thermally reduced graphene (TRG) was synthesized and characterized by X–Ray Diffraction, Transmission Electron Microscopy, and X-Ray Photoelectron Spectroscopy. A two-step extrusion process was used to prepare polypropylene/TRG (PP/TRG) nanocomposites and compared with solution blended composites. The composites were characterized by X-Ray Diffraction, Small Angle X-Ray Scattering, Scanning Electron Microscopy, Differential Scanning Calorimetry, and mechanical properties. Although, PP crystalline structure remained unaltered with the inclusion of TRG and processing route, the morphology and plastic deformation changed drastically in nanocomposites. Furthermore, Small Angle X-Ray Scattering revealed formation of surface graphenic layer in solution-processed PP/TRG responsible for lower property increment consistent with mechanical and thermal properties results. The two-step extrusion led to enhanced homogenous dispersion of TRG; consequently, the melt-processed nanocomposites exhibited better mechanical properties compared with solution-processed nanocomposites.

This study presents a comprehensive investigation on the relationship between structure, synthesis parameters, and porous properties of sol–gel‐derived polymer gels. The formation of the porous gels is monitored with in situ small‐angle X‐ray scattering, in situ nuclear magnetic resonance spectroscopy (NMR), and NMR cryoporometry. The transition of the reaction solution to a solid gel is governed by the consumption of the phenolic monomer. Primary particle growth and nanopore formation proceed during this short time period and are completed when all resorcinol is consumed. The kinetics of these processes are temperature‐dependent and they are completed within 12 min at 120 °C and within 60 min at 80 °C. Extending the reaction time further results in enhanced cross‐linking of the polymer, as observed by solid‐state 13C NMR spectroscopy. Extended reaction time, i.e., higher degree of polymer cross‐linking, enhances pore stability and reduces gel shrinkage during drying, resulting in xerogels with larger pore volume, larger external surface area, and larger average pore sizes. This work rationalizes molecular‐scale transformation of polymers with macroscopic properties, thus providing a rational tool for tuning aerogel/xerogel performance through synthesis design. A comprehensive study shows that chemical composition of the gelation mixture determines the primary particles size and the size of pores they form. Reaction temperature and time define the degree of cross‐linking within the polymer and thus determine the mechanical strength of the gel. High mechanical strength results in low degree of shrinkage during thermal drying.

The goal of this thesis is the structuring of cellulose nanocrystals using different organofunctional silane compounds and different cationic species to prepare highly functional materials with tailored properties. In addition different new aspects and approaches for the structural characterization of functionalised cellulose nanocrystals (CNC) functionalised with different organofunctionalalkoxysilanes as well as cationic species have been introduced. Cellulose nanocrystals (CNC) are prepared using three different acidic conditions to hydrolyse microcrystalline cellulose (MCC). The sulphuric acid hydrolysis introduces highly negative charged sulphate groups on the CNC. The aqueous nanocrystalline cellulose suspensions (aNCS) are analysed in terms of ζ-potential related to the pH and concentration to investigate the stability while dynamic light scattering (DLS) is used to investigate the size distribution. The hydrochloric acid hydrolysis in contrast only removes the amorphous regions but the so obtained CNC are less stabilized (decreased ζ-potential) and tend to agglomerate very fast. The use of the mixture of both acids (HCl and H2SO4) during the hydrolysis of MCC introduces less sulphate groups compared with the sulphuric acid hydrolysis. AFM investigations show that the shapes of the CNC are highly influenced by the hydrolysis conditions. While the shape of the H2SO4 hydrolysed CNC is rod like, while the shape of the other two CNC samples is more spherical in nature. One of the major topic in this work is the analysis of aNCS in aqueous solutions by small angle x-ray scattering (SAXS). The use of the generalized indirect Fourier transformation (GIFT) method allows the analysis of these systems and structural properties such as shape, size and surface charge of aNCS can be assessed. Using this kind of characterisation it can be seen that the shape of the H2SO4 hydrolysed CNC is definitely rod like while the other CNC sample can be described with spheres. In addition to the aNCS characterisation different substrates (Si-wafer, glass slides, polystyrene, etc.) are equipped with aNCS using a variety of different deposition methods (e.g. spin coating, solution casting, dip coating). The resulting films are studied in terms of morphology AFM, SARFUS and SEM. Sophisticated scattering techniques are employed for surface structural characterisation as grazing incidence small angel x-ray scattering. The determination of surface free energies allows conclusions about the hydrophilicity and hydrophobicity as well as the interaction capacity with different liquids. It can be seen that besides the hydrophilic nature of the CNC also hydrophobic interactions are present. The highly negative charged CNC sample which was prepared using sulphuric acid hydrolysis is found to be best suitable for the further hybridization with different organofunctional silanes and for the layer by layer approach (LBL) with different cationic species. The organofunctionalalkoxysilanes which were used in this study can be divided into three groups (e.g filler, surface functionalisation silanes, cross linking silanes). Depending on the nature of the organic residue the silanes are capable to introduce functionalities with enhanced hydrophobic and olephobic properties. The surface energies are investigated using contact angle method, while the surface energies are calculated using three different model approaches (OWRK, Wu, Acid-Base). The most increased hydrophobic and oleophobic properties were measured for trimethylfluorophenylsilantriol (PFTEOS). The morphology of the coated silanes is investigated using SAFRUS technique. It can be seen that nearly all silanes can be coated as homogeneous films onto different substrates (Si-wafer, SURFs, glass slides) with different methods (spin coating, solution casting). The macroscopic appearance of solution casted silanes is investigated using optical microscopy. The differences of the structural nature of the so obtained coatings and detaching films were investigated.

Adhesion-type GPCRs (aGPCRs) participate in a vast range of physiological processes. Their frequent association with mechanosensitive functions suggests that processing of mechanical stimuli may be a common feature of this receptor family. Previously, we reported that the Drosophila aGPCR CIRL sensitizes sensory responses to gentle touch and sound by amplifying signal transduction in low-threshold mechanoreceptors (Scholz et al., 2017). Here, we show that Cirl is also expressed in high-threshold mechanical nociceptors where it adjusts nocifensive behaviour under physiological and pathological conditions. Optogenetic in vivo experiments indicate that CIRL lowers cAMP levels in both mechanosensory submodalities. However, contrasting its role in touch-sensitive neurons, CIRL dampens the response of nociceptors to mechanical stimulation. Consistent with this finding, rat nociceptors display decreased Cirl1 expression during allodynia. Thus, cAMP-downregulation by CIRL exerts opposing effects on low-threshold mechanosensors and high-threshold nociceptors. This intriguing bipolar action facilitates the separation of mechanosensory signals carrying different physiological information.

Leukemia relapse is a major cause of death after allogeneic hematopoietic cell transplantation (allo-HCT). We tested the potential of targeting T cell (Tc) immunoglobulin and mucin-containing molecule 3 (TIM-3) for improving graft-versus-leukemia (GVL) effects. We observed differential expression of TIM-3 ligands when hematopoietic stem cells overexpressed certain oncogenic-driver mutations. Anti-TIM-3 Ab treatment improved survival of mice bearing leukemia with oncogene-induced TIM-3 ligand expression. Conversely, leukemia cells with low ligand expression were anti-TIM-3 treatment resistant. In vitro, TIM-3 blockade or genetic deletion in CD8+ Tc enhanced Tc activation, proliferation, and IFN-γ production while enhancing GVL effects, preventing Tc exhaustion, and improving Tc cytotoxicity and glycolysis in vivo. Conversely, TIM-3 deletion in myeloid cells did not affect allogeneic Tc proliferation and activation in vitro, suggesting that anti-TIM-3 treatment-mediated GVL effects are Tc induced. In contrast to anti-programmed cell death protein 1 (anti-PD-1) and anti-cytotoxic T lymphocyte-associated protein 4 (anti-CTLA-4) treatment, anti-TIM-3-treatment did not enhance acute graft-versus-host disease (aGVHD). TIM-3 and its ligands were frequently expressed in acute myeloid leukemia (AML) cells of patients with post-allo-HCT relapse. We decipher the connections between oncogenic mutations found in AML and TIM-3 ligand expression and identify anti-TIM-3 treatment as a strategy for enhancing GVL effects via metabolic and transcriptional Tc reprogramming without exacerbation of aGVHD. Our findings support clinical testing of anti-TIM-3 Ab in patients with AML relapse after allo-HCT.