Exosomes are physiologically secreted nanoparticles recently established as natural delivery systems involved in cell-to-cell communication and content exchange. Due to their inherent targeting potential, exosomes are currently being harnessed for the development of anti-cancer therapeutics. Clinical trials evaluating their effectiveness are demonstrating safety and promising outcomes. However, challenging largescale production, isolation, modification and purification of exosomes are current limitations for the use of naturally occurring exosomes in the clinic. Exosome mimetics hold the promise to improve the delivery of bioactive molecules with therapeutic efficacy, while achieving scalability and increasing bioavailability. In this study, we propose the development of Immune Derived Exosome Mimetics (IDEM) as a scalable approach to target and defeat ovarian cancer cells. IDEM were fabricated from monocytic cells by combining sequential filtration steps through filter membranes with different porosity and size exclusion chromatography columns. The physiochemical and molecular characteristics of IDEM were compared to those of natural exosomes (EXO). Nanoparticle Tracking Analysis confirmed a 2.48-fold increase in the IDEM production yields compared to EXO, with similar exosomal markers profiles (CD81, CD63) as demonstrated by flow cytometry and ELISA. To exploit the prospective of IDEM to deliver chemotherapeutics, doxorubicin (DOXO) was used as a model drug. IDEM showed higher encapsulation efficiency and drug release over time compared to EXO. The uptake of both formulations by SKOV-3 ovarian cancer cells was assessed by confocal microscopy and flow cytometry, showing an incremental drug uptake over time. The analysis of the cytotoxic and apoptotic effect of DOXOloaded nanoparticles both in 2D and 3D culture systems proved IDEM as a more efficient system as compared to free DOXO, unraveling the advantage of IDEM in reducing side-effects while increasing cytotoxicity of targeted cells, by delivering smaller amount of the chemotherapeutic agent. The high yields of IDEM obtained compared to natural exosomes together with the time-effectiveness and reproducibility of their production method make this approach potentially exploitable for clinical applications.

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Bioinspiration from hierarchical structures found in natural environments has heralded a new age of advanced functional materials. Nanocellulose has received significant attention due to the demand for high-performance materials with tailored mechanical, physical and biological properties. In this study, nanocellulose fibrils, nanocrystals and a novel mixture of fibrils and nanocrystals (blend) were prepared from softwood biomass using the AVAP® biorefinery technology. These materials were characterized using transmission and scanning electron microscopy, and atomic force microscopy. This analysis revealed a nano- and microarchitecture with extensive porosity. Notable differences included the nanocrystals exhibiting a compact packing of nanorods with reduced porosity. The NC blend exhibited porous fibrillar networks with interconnecting compact nanorods. Fourier transform infrared spectroscopy and X-ray diffraction confirmed a pure cellulose I structure. Thermal studies highlighted the excellent stability of all three NC materials with the nanocrystals having the highest decomposition temperature. Surface charge analysis revealed stable colloid suspensions. Rheological studies highlighted a dominance of elasticity in all variants, with the NC blend being more rigid than the NC fibrils and nanocrystals, indicating a double network hydrogel structure. Given these properties, it is thought that these materials show great potential in (bio)nanomaterial applications where careful control of microarchitecture, surface topography and porosity are required.

With current diagnostic methods detection of stage 1 or 2 ovarian cancer using CA125 is possible in only 75% of cases. The ability to detect CA125 at lower concentrations could significantly improve such early stage diagnosis. Here, the use of screen‐printed graphene biosensors as a label‐free detection platform for CA125 was evaluated. The sensor was fabricated through deposition of a polyaniline layer via electropolymerisation on to a graphene screen‐printed electrode. The sensor surface was functionalised with anti‐CA125 antibody via covalent cross linking to polyaniline. The fabrication process was characterised through cyclic voltammetry and electrochemical impedance spectroscopy. The limit of detection achieved was 0.923 ng/μL across a dynamic range of 0.92 pg/μL–15.20 ng/μL and represents the most sensitive CA125 detection reported to date. With sensitivity limits at this level, it will now be possible to conduct clinical trials using serum samples collected from early stage ovarian cancer patients and at risk individuals.

α-amylase is an established marker for diagnosis of pancreatic and salivary disease, and recent research has seen a substantial expansion of its use in therapeutic and diagnostic applications for infection, cancer and wound healing. The lack of bedside monitoring devices for α-amylase detection has hitherto restricted the clinical progress of such applications. We have developed a highly sensitive α-amylase immunosensor platform, produced via in situ electropolymerization of aniline onto a screen-printed graphene support (SPE). Covalently binding an α-amylase specific antibody to a polyaniline (PANI) layer and controlling device assembly using electrochemical impedance spectroscopy (EIS), we have achieved a highly linear response against α-amylase concentration. Each stage of the assembly was characterized using a suite of high-resolution topographical, chemical and mechanical techniques. Quantitative, highly sensitive detection was demonstrated using an artificially spiked human blood plasma samples. The device has a remarkably wide limit of quantification (0.025-1000IU/L) compared to α-amylase assays in current clinical use. With potential for simple scale up to volume manufacturing though standard semiconductor production techniques and subsequently clinical application, this biosensor will enable clinical benefit through early disease detection, and better informed administration of correct therapeutic dose of drugs used to treat α-amylase related diseases.