No abstract

In this study, the chromophore 3,4,9,10-perylenetetracarboxylic diimide (PDI) is anchored with phenyl substituents at the imide N site, followed by thionation, yielding a series of thione products 1S-PDI-D, 2S-cis-PDI-D, 2S-trans-PDI-D, 3S-PDI-D, and 4S-PDI-D, respectively, with n = 1, 2, 3, and 4 thione. The photophysical properties are dependent on the number of anchored thiones, where the observed prominent lower-lying absorption is assigned to the S 0 → S 2 (ππ*) transition and is red-shifted upon increasing the number of thiones; the lowest-lying excited state is ascribed to a transition-forbidden S 1 (nπ*) configuration. All nS-PDIs are non-emissive in solution but reveal an excellent twophoton absorption cross-section of >800 GM. Supported by the femtosecond transient absorption study, the S 1 (nπ*) → T 1 (ππ*) intersystem crossing (ISC) rate is > 10 12 s −1 , resulting in ∼100% triplet population. The lowest-lying T 1 (ππ*) energy is calculated to be in the order of 1S-PDI-D > 2S-cis-PDI-D ∼ 2S-trans-PDI-D > 3S-PDI-D > 4S-PDI-D, where the T 1 energy of 1S-PDI-D (1.10 eV) is higher than that (0.97 eV) of the 1 O 2 1 Δ g state. 1S-PDI-D is further modified by either conjugation with peptide FC131 on the two terminal sides, forming 1S-FC131, or linkage with peptide FC131 and cyanine5 dye on each terminal, yielding Cy5-1S-FC131. In vitro experiments show power of 1S-FC131 and Cy5-1S-FC131 in recognizing A549 cells out of other three lung normal cells and effective photodynamic therapy. In vivo, both molecular composites demonstrate outstanding antitumor ability in A549 xenografted tumor mice, where Cy5-1S-FC131 shows superiority of simultaneous fluorescence tracking and targeted photodynamic therapy.

Cytomegalovirus (CMV) is the most frequent cause of congenital infection worldwide; congenital CMV may lead to significant mortality, morbidity, or long-term sequelae, such as sensorineural hearing loss. The current study presents a newly designed surface plasmon resonance (SPR) biosensor for CMV-specific microRNAs that does not involve extra care for receptor immobilization or treatment to prevent fouling on bare gold surfaces. The modification-free approach, which utilizes a poly-adenine [poly(A)]−Au interaction, exhibited a high affinity that was comparable to that of the gold−sulfur (Au−S) interaction. In addition, magnetic nanoparticles (MNPs) were used to separate the analyte from complex sample matrixes that significantly reduced nonspecific adsorption. Moreover, the MNPs also played an important role in SPR signal amplification due to the binding-induced change in the refractive index. Our SPR biosensing platform was used successfully for the multidetection of the microRNAs, UL22A-5p, and UL112-3p, which were associated with CMV. Our SPR biosensor offered the detection limits of 108 fM and 24 fM for UL22A-5p and UL112-3p, respectively, with an R 2 of 0.9661 and 0.9985, respectively. The precision of this biosensor has an acceptable CV (coefficient of variation) value of <10%. In addition, our sensor is capable of discriminating between serum samples collected from healthy and CMV-infected newborns. Taken together, we believe that our newly developed SPR biosensing platform is a promising alternative for the diagnosis of CMV-specific microRNA in clinical settings, and its application for the detection of other miRNAs may be extended further.

Background Areas of hypoxia are often found in triple-negative breast cancer (TNBC), it is thus more difficult to treat than other types of breast cancer, and may require combination therapies. A new strategy that combined bioreductive therapy with photodynamic therapy (PDT) was developed herein to improve the efficacy of cancer treatment. Our design utilized the characteristics of protoporphyrin IX (PpIX) molecules that reacted and consumed O2 at the tumor site, which led to the production of cytotoxic reactive oxygen species (ROS). The low microenvironmental oxygen levels enabled activation of a bioreductive prodrug, tirapazamine (TPZ), to become a toxic radical. The TPZ radical not only eradicated hypoxic tumor cells, but it also promoted therapeutic efficacy of PDT. Results To achieve the co-delivery of PpIX and TPZ for advanced breast cancer therapy, thin-shell hollow mesoporous Ia3d silica nanoparticles, designated as MMT-2, was employed herein. This nanocarrier designed to target the human breast cancer cell MDA-MB-231 was functionalized with PpIX and DNA aptamer (LXL-1), and loaded with TPZ, resulting in the formation of TPZ@LXL-1-PpIX-MMT-2 nanoVector. A series of studies confirmed that our nanoVectors (TPZ@LXL-1-PpIX-MMT-2) facilitated in vitro and in vivo targeting, and significantly reduced tumor volume in a xenograft mouse model. Histological analysis also revealed that this nanoVector killed tumor cells in hypoxic regions efficiently. Conclusions Taken together, the synergism and efficacy of this new therapeutic design was confirmed. Therefore, we concluded that this new therapeutic strategy, which exploited a complementary combination of PpIX and TPZ, functioned well in both normoxia and hypoxia, and is a promising medical procedure for effective treatment of TNBC.

DNA nanotechnology provides powerful tools for developing cancer theranostics. Here we introduce the autonomous surface‐nucleolin‐guided HCR that leads to the polymerization of G‐quadruplex polymer chains, in which the ZnII‐protoporphyrin IX is intercalated. We demonstrate that MDA‐MB‐231 (Triple Negative Breast Cancer cells, TNBC) with overexpressed surface nucleolin were able to induce HCR leading to the formation of the ZnIIPPIX‐loaded G‐quadruplex polymer chains, while the M10 epithelial breast cells served as control. The ZnIIPPIX‐loaded nanowires allow the selective imaging of TNBC, and their permeation into the TNBC leads to selective cytotoxicity and guided photodynamic therapy toward the cancer cells due to structural perturbation of the membranes. The aptamer‐guided HCR‐generated G‐quadruplex polymer chains may serve as a versatile tool to target TNBC featuring poor prognosis and high pathological risk of recurrence, thus offering a promising theranostic platform.

6‐Cyano‐7‐aminoquinoline (6CN−7AQ) and 3‐cyano‐7‐aminoquinoline (3CN−7AQ) were synthesized and found to exhibit intense emission with quantum yield as high as 63 % and 85 %, respectively, in water. Conversely, their derivatives 6‐cyano‐7‐azidoquinoline (6CN−7N3Q) and 3‐cyano‐7‐azidoquinoline (3CN−7N3Q) show virtually no emission, which makes them suitable to be used as recognition agents in azide reactions based on fluorescence recovery. Moreover, conjugation of 6CN−7AQ with a hydrophobic biomembrane‐penetration peptide PFVYLI renders a nearly non‐emissive 6CN−7AQ‐PFVYLI composite, which can be digested by proteinase K, recovering the highly emissive 6CN−7AQ with ∼200‐fold enhancement. The result provides an effective early confirmation for RT‐qPCR in viral detection.