Anticancer therapies are often compromised by nonspecific effects and challenged by tumour environments’ inherent physicochemical and biological characteristics. Often, therapeutic effect can be increased by addressing multiple parameters simultaneously. Here we report on exploiting extravasation due to inherent vascular leakiness for the delivery of a pH-sensitive polymer carrier. Tumours’ acidic microenvironment instigates a charge reversal that promotes cellular internalization where endosomes destabilize and gene delivery is achieved. We assess our carrier with an aggressive non-small cell lung carcinoma (NSCLC) in vivo model and achieve >30% transfection efficiency via systemic delivery. Rejuvenation of the p53 apoptotic pathway as well as expression of KillerRed protein for sensitization in photodynamic therapy (PDT) is accomplished. A single administration greatly suppresses tumour growth and extends median animal survival from 28 days in control subjects to 68 days. The carrier has capacity for multiple payloads for greater therapeutic response where inter-individual variability can compromise efficacy.

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Clinical virotherapy has been successfully approved for use in cancer treatment by the U.S. Food and Drug Administration; however, a number of improvements are still sought to more broadly develop virotherapy. A particular challenge is to administer viral therapy systemically and overcome limitations in intratumoral injection, especially for complex tumors within sensitive organs. To achieve this, however, a technique is required that delivers the virus to the tumor before the body's natural self-defense eradicates the virus prematurely. Here we show that recombinant adeno-associated virus serotype 2 (AAV2) chemically conjugated with iron oxide nanoparticles (∼5 nm) has a remarkable ability to be remotely guided under a magnetic field. Transduction is achieved with microscale precision. Furthermore, a gene for production of the photosensitive protein KillerRed was introduced into the AAV2 genome to enable photodynamic therapy (PDT), or light-triggered virotherapy. In vivo experiments revealed that magnetic guidance of "ironized" AAV2-KillerRed injected by tail vein in conjunction with PDT significantly decreases the tumor growth via apoptosis. This proof-of-principle demonstrates guided and highly localized microscale, light-triggered virotherapy.

Solid tumors characteristically display higher levels of lactate production due to anaerobic metabolism of glucose. Meanwhile, the U.S. Food and Drug Administration (FDA) has approved virotherapy for use in cancer treatment; however systemic administration remains as a particular challenge. Here we report exploitation of tumor lactate production in designing a hypoxia-responsive carrier, self-assembled from hyaluronic acid (HA) conjugated with 6-(2-nitroimidazole)­hexylamine, for localized release of recombinant adeno-associated virus serotype 2 (AAV2). The carrier is loaded with lactate oxidase (LOX) and is permeable to small molecules such as the lactate that accumulates in the tumor. Subsequently, LOX oxidizes the lactate to pyruvate inside the carrier, accompanied by internal lowering of oxygen partial pressure. Bioreduction of the 2-nitroimidazole of the HA conjugated with 6-(2-nitroimidazole)­hexylamine converts it into a hydrophilic moiety and electrostatically dissociates the carrier and virus. Efficacious and specific delivery was proven by transduction of a photosensitive protein (KillerRed), enabling significant limitation in tumor growth in vivo with photodynamic therapy. An approximate 2.44-fold reduction in tumor weight was achieved after a 2-week course, compared with control groups. Furthermore, conjugation of the AAV2 with iron oxide nanoparticles (“magnetized” AAV2) facilitated magnetic resonance imaging tracking of the virus in vivo. Taken together, the solid tumor microenvironment promotes bioreduction of the lactate-responsive carrier, providing rapid and specific delivery of AAV2 for light-triggered virotherapy via systemic administration.

Novel electron transfer results in PL quenching in both graphene oxide–Au25 and graphene oxide–Au10 nanocomposites.

The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants has altered the trajectory of the COVID-19 pandemic and raised some uncertainty on the long-term efficiency of vaccine strategy. The development of new therapeutics against a wide range of SARS-CoV-2 variants is imperative. We, here, have designed an inhalable siRNA, C6G25S, which covers 99.8% of current SARS-CoV-2 variants and is capable of inhibiting dominant strains, including Alpha, Delta, Gamma, and Epsilon, at picomolar ranges of IC 50 in vitro. Moreover, C6G25S could completely inhibit the production of infectious virions in lungs by prophylactic treatment, and decrease 96.2% of virions by cotreatment in K18-hACE2transgenic mice, accompanied by a significant prevention of virusassociated extensive pulmonary alveolar damage, vascular thrombi, and immune cell infiltrations. Our data suggest that C6G25S provides an alternative and effective approach to combating the COVID-19 pandemic.

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We utilize single-molecule spectroscopy combined with time-correlated single-photon counting to probe the electron transfer (ET) rates from various types of semiconductor hetero-nanocrystals, having either type-I or type-II band alignment, to single-walled carbon nanotubes. A significantly larger ET rate was observed for type-II ZnSe/CdS dot-in-rod nanostructures as compared to type-I spherical CdSe/ZnS core/shell quantum dots and to CdSe/CdS dot-in-rod structures. Furthermore, such rapid ET dynamics can compete with both Auger and radiative recombination processes, with significance for effective photovoltaic operation.