An Aggregation-Induced Emission-Based Dual Emitting Nanoprobe for Detecting Intracellular pH and Unravelling Metabolic Variations in Differentiating Lymphocytes

Monitoring T lymphocyte differentiation is essential for understanding T cell fate regulation and advancing adoptive T cell immunotherapy. However, current biomarker analysis methods necessitate cell lysis, leading to source depletion. Intracellular pH (pHi) can be affected by the presence of lactic acid (LA), a metabolic mediator of T cell activity such as glycolysis during T cell activation; therefore, it is a potentially a good biomarker of T cell state. In this work, a dual emitting enhancement-based nanoprobe, namely, AIEgen@F127-AptCD8, was developed to accurately detect the pHi of T cells to "read" the T cell differentiation process. The nanocore of this probe comprises a pair of AIE dyes, TPE-AMC (pH-sensitive moiety) and TPE-TCF, that form a donor-acceptor pair for sensitive detection of pHi by dual emitting enhancement analysis. The nanoprobe exhibits a distinctly sensitive narrow range of pHi values (from 6.0 to 7.4) that can precisely distinguish the differentiated lymphocytes from naïve ones based on their distinct pHi profiles. Activated CD8+ T cells demonstrate lower pHi (6.49 ± 0.09) than the naïve cells (7.26 ± 0.11); Jurkat cells exhibit lower pHi (6.43 ± 0.06) compared to that of nonactivated ones (7.29 ± 0.09) on 7 days post-activation. The glycolytic product profiles in T cells strongly correlate with their pHi profiles, ascertaining the reliability of probing pHi for predicting T cell states. The specificity and dynamic detection capabilities of this nanoprobe make it a promising tool for indirectly and noninvasively monitoring T cell activation and differentiation states.

Folic acid grafted mixed polymeric micelles as a targeted delivery strategy for tamoxifen citrate in treatment of breast cancer

The objective of this study was to develop folic acid (FA) grafted mixed polymeric micelles loaded with Tamoxifen citrate (TMXC) to enhance its antitumor activity in breast tissues. The conjugated folic acid Pluronic 123 (FA-P123) was prepared using carbonyl diimidazole cross-linker chemistry and confirmed using FTIR and 1HNMR. TMXC-loaded P123/P84 (unconjugated) and TMXC-loaded FA-P123/P84 (conjugated) micelles were examined for encapsulation efficiency, particle size, surface charge, in vitro drug release, cytotoxic effect, and cellular uptake by a breast cancer cell line. The conjugated TMXC-loaded micelle exhibited a nanoparticle size of 35.01 ± 1.20 nm, a surface charge of-20.50 ± 0.95 mV, entrapped 87.83 ± 5.10% and released 67.58 ± 2.47% of TMXC after 36 h. The conjugated micelles exhibited a significantly higher cellular uptake of TMXC by the MCF-7 cell line and improved in vitro cytotoxicity by 2.48 folds compared to the TMXC-loaded unconjugated micelles. The results of in vivo studies indicated that TMXC-loaded FA-P123/P84 has a potential antitumor activity, as revealed by a significant reduction of tumor volume in tumor-bearing mice compared to TMXC-loaded unconjugated micelles. In conclusion, the obtained results suggested that conjugated FA-P123/P84 micelles could be an encouraging carrier for the treatment of breast cancer with TMXC.

1, 2-Dihexadecanoyl-sn-glycero-3-phosphoethanolamin (DPPE), doxorubicin and folic acid conjugated micelles for cancer management in tumor bearing BALB/c mice

Aim of the present investigation was to assess and compare the in-vitro and in-vivo cancer targeting propensity of DPPE-FA-DOX Micelles and free DOX in tumor bearing BALB/c mice. The DOX was conjugated with 1, 2-Dihexadecanoyl-sn-glycero-3-phosphoethanolamin (DPPE) and folic acid using Di-cyclohexyl-carbodiimide, confirmed by Fourier transform infrared spectroscopy (FTIR) and proton NMR. DPPE-FA-DOX micelles were prepared using thin film method and evaluated for zeta potential, particle size, surface morphology, in- vitro drug release study etc. In-vitro anticancer activity and apoptosis assay was evaluated in breast cancer (MCF-7) cells using MTT assay and flow cytometer respectively. In-vivo biodistribution and toxicity assessment were evaluated in rats whereas antitumor activity in tumor bearing BALB/c mice. Prepared micelles were spherical with size and zeta potential of 295.6 + 84.4 nm and 0.8 ± 0.24 mV respectively. Apoptosis assay for DPPE-FA-DOX micelles treated cells using Annexin V/PI staining demonstrated 56.2% apoptotic cells. Remarkably, DPPE-FA-DOX micelles improved DOX bioavailability by 7 fold and diminished plasma elimination with no sign of tissue toxicity compared to free DOX. In-vivo biodistribution studies revealed that micelles facilitated higher accumulation of DOX in tumor than free DOX. DPPE-FA-DOX micelles treated mice survived for 62 days than Free DOX (40 days), revealed by Kaplan-Meier survival curve analysis. Histopathological examination of liver, kidney and heart tissues of micelles treated rat's corroborated reduced systemic toxicity than free DOX. Conclusively, DPPE-FA-DOX micelles could potentially facilitate the targeted delivery of DOX to tumors.

Multifunctional CuO/Cu2O Truncated Nanocubes as Trimodal Image-Guided Near-Infrared-III Photothermal Agents to Combat Multi-Drug-Resistant Lung Carcinoma

Despite the development of various therapeutic modalities to tackle cancer, multidrug resistance (MDR) and incomplete destruction of deep tissue-buried tumors remain as long-standing challenges responsible for tumor recurrence and low survival rates. In addition to the MDR and deep tissue photoactivation problems, most primary tumors metastasize to the lungs and lymph nodes to form secondary tumors. Therefore, it leaves a great challenge to develop theranostic approaches to combat both MDR and deep tissue photoactivation problems. Herein, we develop a versatile plasmonic CuO/Cu₂O truncated nanocube-based theranostic nanomedicine to act as a triple modal near-infrared fluorescence (NIRF) imaging agent in the biological window II (1000-1500 nm)/photoacoustic imaging (PAI)/T₁-weighted magnetic resonance (MR) imaging agents, sensitize the formation of singlet oxygen (¹O₂) to exert nanomaterial-mediated photodynamic therapeutic (NIR-II NmPDT), and absorb long NIR light (i.e., 1550 nm) in the biological window III (1500-1700 nm) to exert nanomaterial-mediated photothermal therapeutic (NIR-III NmPTT) effects for the effective destruction of multi-drug-resistant lung tumors. We found that H69AR lung cancer cells do not create drug resistance toward plasmonic CuO/Cu₂O TNCs-based nanomedicines.

Single-Entity Electrochemistry of Nanoemulsion: The Nanostructural Effect on Its Electrochemical Behavior

New electrochemical approaches have been applied to investigate nanoemulsions (NEs) for their nanostructures and the relevant electrochemical activity by single-entity electrochemistry (SEE). Herein, we make highly monodisperse NEs with ∼40 nm diameter, composed of biocompatible surfactants, castor oil as plasticizers, and ion exchangers. Dynamic light scattering (DLS) measurements with periodically varying surfactant to oil ratios provide us with a structural implication about uneven distributions of incorporating components inside NEs. To support this structural insight, we apply SEE and selectively monitor electron-transfer reactions occurring at individual NEs containing ferrocene upon each collision onto a Pt ultramicroelectrode. The quantitative analysis of the nanoelectrochemical results along with DLS and transmission electron microscopy (TEM) measurements reveal nanostructured compartments of incorporating components inside NEs and their effect on the electrochemical behavior. Indeed, a tunneling barrier inside NEs could be formed depending on the NE composition, thus determining an electrochemical behavior of NEs, which cannot be differentiated by a general morphological study such as DLS and TEM but by our SEE measurements. Furthermore, by employing the nanopipet voltammetry with an interface between two immiscible electrolyte solutions (ITIES) to mimic the NE interface, we could explicitly investigate that the electron-transfer reaction occurring inside NEs is facilitated by the ion-transfer reaction. Overall, these comprehensive electrochemical approaches enable us to elucidate the relation between structures and the electrochemical functionality of NEs and provide quantitative criteria for the proper compositions of NEs regarding their activity in the electrochemical applications. Also, this finding should be a prerequisite for suitable biomedical/electrochemical applications of NEs.

Doxorubicin-DNA adduct entrenched and motif tethered artificial virus encased in pH-responsive polypeptide complex for targeted cancer therapy

Doxorubicin is a broad spectrum anticancer antibiotic that possesses toxic effects such as cardiomyopathy, that even lead to congestive heart failure. Thus, the development of a new bio-inspired system is required, that retain the advantageous effect of doxorubicin while retarding the side effects. Hence, a system was developed that we describe 'doxorubicin-DNA adduct entrenched artificial virus encased in polypeptide complex'. The drug-DNA adduct (DDA) was prepared by a formaldehyde mediated reaction. A simple chloroform extraction method for the separation of DDA was developed. DDA was employed to self-assemble the folate tethered bovine serum albumin to form the protein coat in the proposed artificial virus. The folate tethered albumin provides an artificial virus concept, with tumor tissue targeting due to the presence of folate. The whole system was then encased in a pH-responsive polypeptide complex that dissolves in acidic pH, but not in basic pH. DDA was evaluated by UV-Vis spectrophotometry, spectrofluorimetry and high-performance liquid chromatography (HPLC). A promising drug release at physiological condition was observed from DDA. The developed system was evaluated by a developed and validated artificial cell apparatus that mimic the features of a cancer cell. The drug delivery system displayed a considerable amount of drug release within 24 h. Moreover, the developed artificial virus system reduced angiogenesis caused by tumor cells in chick chorioallantoic membrane. Histopathology of treated chicken heart slices demonstrated that the developed artificial virus system reduces the tissue deformation and apoptosis in heart tissue slices, thus providing a new approach to prevent Dox-induced cardiomyopathy.

Development of fisetin-loaded folate functionalized pluronic micelles for breast cancer targeting

The natural flavonoid fisetin (FS) has shown anticancer properties but its in-vivo administration remains challenging due to its poor aqueous solubility. The aim of the study was to develop FS loaded pluronic127 (PF)-folic acid (FA) conjugated micelles (FS-PF-FA) by the way of increasing solubility, bioavailability and active targetability of FS shall increase its therapeutic efficacy. FA-conjugated PF was prepared by carbodiimide crosslinker chemistry. FS-PF-FA micelles were prepared by thin-film hydration method and evaluated in comparison with free FS and FS loaded PF micelles (FS-PF). The smooth surfaces with spherical in shape of FS-PF-PF micelles displayed smaller in size (103.2 ± 6.1 nm), good encapsulation efficiency (82.50 ± 1.78%), zeta potential (-26.7 ± 0.44 mV) and sustained FS release. Bioavailability of FS from FS-PF-PF micelles was increased by 6-fold with long circulation time, slower plasma elimination and no sign of tissue toxicity as compared to free FS. Further, the FS-PF-FA micelles demonstrated active targeting effect on folate overexpressed human breast cancer MCF-7 cells. The concentration of the drug needed for growth inhibition of 50% of cells in a designed time period (GI50) was 14.3 ± 1.2 µg/ml for FS while it was greatly decreased to 9.8 ± 0.78 µg/ml, i.e. a 31.46% decrease for the FS-PF. Furthermore, the GI50 value for FS-PF-FA was 4.9 ± 0.4 µg/ml, i.e. a 65.737% decrease compared to FS and 50% decrease compare to FS-PF. The results indicate that the FS-PF-FA micelles have the potential to be applied for targeting anticancer drug delivery.

Nanoarmoring of Proteins by Conjugation to Block Copolymer Micelles

The creation of polymer nanoparticles with protein functionality is of great interest to many applications such as targeted drug or gene delivery, diagnostic imaging, cancer theranostics, delivery of protein therapeutics, sensing chemical and biomolecular analytes in complex environments, and design of protective clothing resembling a second skin. Many approaches to achieving this goal are being explored in the current literature. In this chapter, we describe a relatively simple and flexible approach of conjugating the protein to an amphiphilic block copolymer and creating polymer nanoparticles with protein functionality by taking advantage of the intrinsic self-assembly behavior of the amphiphilic block copolymer. The commercially available and biocompatible polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer is used as the polymer building block. For demonstrative purposes, bovine serum albumin was chosen as the protein. We determine the molecular weight of the protein-polymer conjugate and thereby the degree of conjugation using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry measurements. Retention of protein secondary structure in the conjugate was determined by circular dichroism spectroscopy, and the biological activity of the protein in the conjugated state has been evaluated by kinetic assay involving hydrolysis of an organophosphate compound. Dynamic light scattering and zeta potential measurements were used to characterize the size and charge of the protein-polymer conjugate micelle. Precise control of the size of the micelle and surface number density of the proteins on the micelle surface by coassembling with a second block copolymer have been demonstrated. These studies document a rational approach to armor the protein by conjugation with a block copolymer micelle, as a general approach.

Nanoscale hydrophilic colloids with high relaxivity and low cytotoxicity based on Gd(iii) complexes with Keplerate polyanions

Efficient hydrophilic stabilization of Gd(iii) complexes with Keplerate polyanions for high relaxivity, colloid stability and low cytotoxicity.

Enhancing enzyme stability by construction of polymer-enzyme conjugate micelles for decontamination of organophosphate agents

Enhancing the stability of enzymes under different working environments is essential if the potential of enzyme-based applications is to be realized for nanomedicine, sensing and molecular diagnostics, and chemical and biological decontamination. In this study, we focus on the enzyme, organophosphorus hydrolase (OPH), which has shown great promise for the nontoxic and noncorrosive decontamination of organophosphate agents (OPs) as well as for therapeutics as a catalytic bioscavanger against nerve gas poisoning. We describe a facile approach to stabilize OPH using covalent conjugation with the amphiphilic block copolymer, Pluronic F127, leading to the formation of F127-OPH conjugate micelles, with the OPH on the micelle corona. SDS-PAGE and MALDI-TOF confirmed the successful conjugation, and transmission electron microscopy (TEM) and dynamic light scattering (DLS) revealed ∼100 nm size micelles. The conjugates showed significantly enhanced stability and higher activity compared to the unconjugated OPH when tested (i) in aqueous solutions at room temperature, (ii) in aqueous solutions at higher temperatures, (iii) after multiple freeze/thaw treatments, (iv) after lyophilization, and (v) in the presence of organic solvents. The F127-OPH conjugates also decontaminated paraoxon (introduced as a chemical agent simulant) on a polystyrene film surface and on a CARC (Chemical Agent Resistant Coating) test panel more rapidly and to a larger extent compared to free OPH. We speculate that, in the F127-OPH conjugates (both in the micellar form as well as in the unaggregated conjugate), the polypropylene oxide block of the copolymer interacts with the surface of the OPH and this confinement of the OPH reduces the potential for enzyme denaturation and provides robustness to OPH at different working environments. The use of such polymer-enzyme conjugate micelles with improved enzyme stability opens up new opportunities for numerous civilian and Warfighter applications.