Synthesis and Characterization of Diketopyrrolopyrrole-Based Aggregation-Induced Emission Nanoparticles for Bioimaging.

Conventional fluorescent dyes have the property of decreasing fluorescence due to aggregation-caused quenching effects at high concentrations, whereas aggregation-induced emission dyes have the property of increasing fluorescence as they aggregate with each other. In this study, diketopyrrolopyrrole-based long-wavelength aggregation-induced emission dyes were used to prepare biocompatible nanoparticles suitable for bioimaging. Aggregation-induced emission nanoparticles with the best morphology and photoluminescence intensity were obtained through a fast, simple preparation method using an ultrasonicator. The optimally prepared nanoparticles from 3,6-bis(4-((E)-4-(bis(40-(1,2,2-triphenylvinyl)-[1,10-biphenyl]-4-yl)amino)styryl)phenyl)-2,5-dihexyl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DP-R2) with two functional groups having aggregation-induced emission properties and additional donating groups at the end of the triphenylamine groups were considered to have the greatest potential as a fluorescent probe for bioimaging. Furthermore, it was found that the tendency for aggregation-induced emission, which was apparent for the dye itself, became much more marked after the dyes were incorporated within nanoparticles. While the photoluminescence intensities of the dyes were observed to decrease rapidly over time, the prepared nanoparticles encapsulated within the biocompatible polymers maintained their initial optical properties very well. Lastly, when the cell viability test was conducted, excellent biocompatibility was demonstrated for each of the prepared nanoparticles.

Development of an anti-EPO antibody detection kit based on lab-on-a-chip and bridging antibody technologies.

Immunogenicity is a major concern in the use of biological drugs. In particular, antibody-mediated pure red cell aplasia (PRCA) is a rare condition that is caused by administration of recombinant erythropoietin. There are numerous assay platforms for detect EPO anti-drug antibody (ADA), and most have appropriate assay sensitivity, but in need of improvement in terms of assay turnaround time and user accessibility. Here, the new method was developed based on lab-on-a-chip technology and bridging ELISA. The FREND™ Cartridge is equipped with a microfluidic lateral flow channel, enabling easy, fast and accurate immunoassays with small sample volumes. Biotinylated EPO was immobilized on the avidin-coated solid phase of the test zone in the FREND™ cartridge. Initially, ADA in the serum sample binds to the detector conjugate (EPO-HRP-anti HRP antibody-FL bead) in the conjugation zone, and it flows into the test zone prepared with capture complex (avidin-biotinylated EPO). Unbound detector complexes are captured in the reference zone. The FREND™ system detects and quantifies the fluorescence signals in each zone and then calculates the concentration of EPO ADA in the sample. The FREND™ EPO ADA kit may be useful in local clinics as a rapid method for monitoring patients administered recombinant erythropoietin.

Dielectrophoretic Capture of Cancer-Derived Small-Extracellular-Vesicle-Bound Janus Nanoparticles via Lectin-Glycan Interaction.

Glycosylation is closely related to cellular metabolism and disease progression. In particular, glycan levels in cancer cells and tissues increase during cancer progression. This upregulation of glycosylation in cancer cells may provide a basis for the development of new biomarkers for the targeting and diagnosis of specific cancers. Here, they developed a detection technology for pancreatic cancer cell-derived small extracellular vesicles (PC-sEVs) based on lectin-glycan interactions. Lectins specific for sialic acids are conjugated to Janus nanoparticles to induce interactions with PC-sEVs in a dielectrophoretic (DEP) system. PC-sEVs are selectively bound to the lectin-conjugated Janus nanoparticles (lectin-JNPs) with an affinity comparable to that of conventionally used carbohydrate antigen 19-9 (CA19-9) antibodies. Furthermore, sEVs-bound Lectin-JNPs (sEVs-Lec-JNPs) are manipulated between two electrodes to which an AC signal is applied for DEP capture. In addition, the proposed DEP system can be used to trap the sEVs-Lec-JNP on the electrodes. Their results, which are confirmed by lectin-JNPs using the proposed DEP system followed by target gene analysis, provide a basis for the development of a new early diagnostic marker based on the glycan characteristics of PC-sEVs. In turn, these novel detection methods could overcome the shortcomings of commercially available pancreatic cancer detection techniques.

Ex vivo activation of dendritic cells via coacervate-mediated exogenous tumor cell lysate delivery.

For the successful development of various cellular products in cancer immunotherapy, an effective ex vivo priming technique for immune cells is often required. Among a variety of immunomodulatory substances, tumor cell lysates (TCLs) have been considered a robust immune activator with high adjuvanticity and tumor antigen population. Therefore, the present study suggests a novel ex vivo dendritic cell (DC) priming technique that utilizes (1) squaric acid (SqA)-mediated oxidation of source tumor cells to obtain antigenic TCLs with an increased immunogenic potential and (2) a coacervate (Coa) colloidal complex as an exogenous TCL carrier. Elevated oxidation by SqA-treated source tumor cells resulted in an increased immunogenic potential, indicated by a high level of damage-associated molecular pattern molecules in TCLs that could sufficiently stimulate DCs. Moreover, to effectively deliver these exogenous immunomodulating TCL DCs, Coa (i.e., a colloidal micro-carrier using cationic mPEGylated poly(ethylene arginyl aspartate diglyceride) and anionic heparin) was utilized for the sustained release of cargo TCLs and for preserving their bioactivity. Coa-mediated ex vivo delivery of SqA-treated TCLs (SqA-TCL-Coa) effectively promoted DC maturation through the enhanced uptake of antigens into target DCs, increased expression of DC activation markers, facilitated secretion of pro-inflammatory cytokines from activated DCs, and improved major histocompatibility complex-I dependent cross-presentation of a colorectal cancer specific antigen. Therefore, based on antigenic and adjuvant behaviors, our Coa-mediated exogenous delivery of SqA-TCL could be a promising application as a facile ex vivo DC priming strategy for further cell-based cancer immunotherapies.

Activation of Cellular Players in Adaptive Immunity via Exogenous Delivery of Tumor Cell Lysates.

Tumor cell lysates (TCLs) are a good immunogenic source of tumor-associated antigens. Since whole necrotic TCLs can enhance the maturation and antigen-presenting ability of dendritic cells (DCs), multiple strategies for the exogenous delivery of TCLs have been investigated as novel cancer immunotherapeutic solutions. The TCL-mediated induction of DC maturation and the subsequent immunological response could be improved by utilizing various material-based carriers. Enhanced antitumor immunity and cancer vaccination efficacy could be eventually achieved through the in vivo administration of TCLs. Therefore, (1) important engineering methodologies to prepare antigen-containing TCLs, (2) current therapeutic approaches using TCL-mediated DC activation, and (3) the significant sequential mechanism of DC-based signaling and stimulation in adaptive immunity are summarized in this review. More importantly, the recently reported developments in biomaterial-based exogenous TCL delivery platforms and co-delivery strategies with adjuvants for effective cancer vaccination and antitumor effects are emphasized.