Peijian Feng

Light-Activated Hypoxia-Responsive Nanocarriers for Enhanced Anticancer Therapy.

A light-activated hypoxia-responsive conjugated polymer-based nanocarrier is developed for efficiently producing singlet oxygen ((1) O2 ) and inducing hypoxia to promote release of its cargoes in tumor cells, leading to enhanced antitumor efficacy. This dual-responsive nanocarrier provides an innovative design guideline for enhancing traditional photodynamic therapeutic efficacy integrated with a controlled drug-release modality.

Conjugated Polymer Nanoparticles for Fluorescence Imaging and Sensing of Neurotransmitter Dopamine in Living Cells and the Brains of Zebrafish Larvae

Nanoscale materials are now attracting a great deal of attention for biomedical applications. Conjugated polymer nanoparticles have remarkable photophysical properties that make them highly advantageous for biological fluorescence imaging. We report on conjugated polymer nanoparticles with phenylboronic acid tags on the surface for fluorescence detection of neurotransmitter dopamine in both living PC12 cells and brain of zebrafish larvae. The selective enrichment of dopamine and fluorescence signal amplification characteristics of the nanoparticles show rapid and high-sensitive probing such neurotransmitter with the detection limit of 38.8 nM, and minimum interference from other endogenous molecules. It demonstrates the potential of nanomaterials as a multifunctional nanoplatform for targeting, diagnosis, and therapy of dopamine-relative disease.

Anaerobe‐Inspired Anticancer Nanovesicles

Anaerobic bacteria, such as Clostridium and Salmonella, can selectively invade and colonize in tumor hypoxic regions (THRs) and deliver therapeutic products to destroy cancer cells. Herein, we present an anaerobe nanovesicle mimic that can not only be activated in THRs but also induce hypoxia in tumors by themselves. Moreover, inspired by the oxygen metabolism of anaerobes, we construct a light-induced hypoxia-responsive modality to promote dissociation of vehicles and activation of bioreductive prodrugs simultaneously. In vitro and in vivo experiments indicate that this anaerobe-inspired nanovesicle can efficiently induce apoptotic cell death and significantly inhibit tumor growth. Our work provides a new strategy for engineering stimuli-responsive drug delivery systems in a bioinspired and synergistic fashion.

Conjugated polymer nanomaterials for theranostics

Conjugated polymer nanomaterials (CPNs), as optically and electronically active materials, hold promise for biomedical imaging and drug delivery applications. This review highlights the recent advances in the utilization of CPNs in theranostics. Specifically, CPN-based in vivo imaging techniques, including near-infrared (NIR) imaging, two-photon (TP) imaging, photoacoustic (PA) imaging, and multimodal (MM) imaging, are introduced. Then, CPN-based photodynamic therapy (PDT) and photothermal therapy (PTT) are surveyed. A variety of stimuli-responsive CPN systems for drug delivery are also summarized, and the promising trends and translational challenges are discussed.

Bioinspired Ferroelectric Polymer Arrays as Photodetectors with Signal Transmissible to Neuron Cells

A bioinspired photodetector with signal transmissible to neuron cells is fabricated. Photoisomerization of the dye molecules embedded in the ferroelectric polymer membrane achieves electric polarization change under visible light. The photodetector realizes high sensitivity, color recognition, transient response, and 3D visual detection with resolution of 25 000 PPI, and, impressively, directly transduces the signal to neuron cells.

ROS-Responsive Microneedle Patch for Acne Vulgaris Treatment

Acne vulgaris is a common inflammatory skin disease associated with a colonization of Propionibacterium acnes (P. acnes), which can cause both physiological and psychological impact to the patients. Although antibiotic cream is commonly used to treat acne, limited transport of drug to the lesions within the pilosebaceous unit leads to poor bactericidal effect. Here, the authors described a new method of drug administration using a reactive oxygen species (ROS)‐responsive microneedle (MN) patch for anti‐acne therapy. Compared to the commonly used anti‐acne cream, enhanced efficacy toward dermis lesions can be achieved through the skin penetration by MNs. A controlled and sustained drug release in response to the over‐generated ROS within acne is also important for improving the antibacterial effect and reducing the side effects. In addition, the patch base, formed by hyaluronic acid (HA) and diatomaceous earth (DE) with high physical adsorption capability, is beneficial for accelerating healing of skin via the absorption of pus and dead cell debris. In vivo studies in a P. acnes‐induced mouse model demonstrated this bioresponsive patch with adsorption capability could efficiently reduce the skin swelling and inhibit the bacterial growth.

Near-Infrared Fluorescent Nanoprobes for Revealing the Role of Dopamine in Drug Addiction

Brain imaging techniques enable visualizing the activity of central nervous system without invasive neurosurgery. Dopamine is an important neurotransmitter. Its fluctuation in brain leads to a wide range of diseases and disorders, like drug addiction, depression, and Parkinsons disease. We designed near-infrared fluorescence dopamine-responsive nanoprobes (DRNs) for brain activity imaging during drug abuse and addiction process. On the basis of light-induced electron transfer between DRNs and dopamine and molecular wire effect of the DRNs, we can track the dynamical change of the neurotransmitter level in the physiological environment and the releasing of the neurotransmitter in living dopaminergic neurons in response to nicotine stimulation. The functional near-infrared fluorescence imaging can dynamically track the dopamine level in the mice midbrain under normal or drug-activated condition and evaluate the long-term effect of addictive substances to the brain. This strategy has the potential for studying neural activity under physiological condition.

Anticancer Therapy: Light-Activated Hypoxia-Responsive Nanocarriers for Enhanced Anticancer Therapy (Adv. Mater. 17/2016).

A light-activated hypoxia-responsive drug-delivery vehicle is described by Q.-D. Shen, Z. Gu, and co-workers on page 3313. This conjugated-polymer-based nanocarrier can be activated by photoirradiation, producing singlet oxygen ((1) O2 ) and inducing hypoxia to promote release of its cargo inside tumor cells for enhanced anticancer efficacy.