Any design of nanoparticle vectors for cancer therapy or imaging must take into account the interaction of the nanoparticles with the tumor microenvironment. Size, charge, and shape have been shown to dominate this interaction.[1, 2] In vivo probing of solid tumors with particles of different sizes simultaneously has thus far been challenging due to the limitations of available nano-sized probes.[3–5] Fluorescent dextrans and other macromolecule probes have been used in studies with intravital microscopy, but heterogeneities across samples has prevented their use for the simultaneous imaging of a size series of probes within the same tumour.[5] MRI contrast agents are another attractive set of probes due to the minimally-invasive nature of the technology,[6, 7] but the lower spatial resolution of MRI limits the imaging of heterogeneity within tumors, and the technique does not allow for simultaneous imaging and tracking of a size series of probes within the same tumor.

A Nanoparticle Size Series for In Vivo Fluorescence Imaging

Recent progress of chemodynamic therapy-induced combination cancer therapy

Polydopamine (PDA) is the most typical kind of synthetic melanin, which possesses interesting properties such as antioxidation, photoprotection, metal chelation, and energy dissipation. Over the past few years, PDA has been successfully synthesized via polymerization methods and has demonstrated excellent free radical scavenging ability. The related applications have been rapidly expanded to include sunscreens, anti-inflammatory treatment, and composite material fabrication. Despite great progress, the comprehensive mechanisms of its free radical scavenging behaviors are not fully understood. This article strives to summarize the possible mechanisms, established antioxidant regulation methods and the related biomedical applications of PDA free radical scavengers. We believe this paper can provide insight into the current PDA scavenging systems and offer inspiration towards the design of new melanin-inspired scavengers with a broad range of biomedical applications.

https://pubs.rsc.org/en/content/articlepdf/2020/bm/d0bm01070g

Polydopamine free radical scavengers

Intelligent skinlike materials have recently attracted tremendous research interests for employing in electronic skin, soft robotics, and wearable devices. Because the traditional soft matters are ...

Eco-Friendly, Self-Healing Hydrogels for Adhesive and Elastic Strain Sensors, Circuit Repairing, and Flexible Electronic Devices

The past decades have witnessed an increasing interest in developing advanced polymerization techniques subjected to external fields. Various physical modulations, such as temperature, light, electricity, magnetic field, ultrasound, and microwave irradiation, are noninvasive means, having superb but distinct abilities to regulate polymerizations in terms of process intensification and spatial and temporal controls. Gas as an emerging regulator plays a distinctive role in controlling polymerization and resembles a physical regulator in some cases. This review provides a systematic overview of seven types of external-field-regulated polymerizations, ranging from chain-growth to step-growth polymerization. A detailed account of the relevant mechanism and kinetics is provided to better understand the role of each external field in polymerization. In addition, given the crucial role of modeling and simulation in mechanisms and kinetics investigation, an overview of model construction and typical numerical methods used in this field as well as highlights of the interaction between experiment and simulation toward kinetics in the existing systems are given. At the end, limitations and future perspectives for this field are critically discussed. This state-of-the-art research progress not only provides the fundamental principles underlying external-field-regulated polymerizations but also stimulates new development of advanced polymerization methods.

Role of External Field in Polymerization: Mechanism and Kinetics.

Nanoengineering of polymer-based therapeutic carriers is promising for precise cancer treatment. Herein, we report the fabrication of polypeptide vehicles encapsulated with anticancer drug of cisplatin (Pt drug) and Fe3O4 nanoparticles (denoted as Pt&Fe3O4@PP) as theranostics for T2-weighted magnetic resonance imaging (MRI)-guided chemo-ferroptosis combination therapy. The number of Fe3O4 nanoparticles per polypeptide vehicle is well controlled by adjusting the added amount of Fe3O4 nanoparticles. The tumor microenvironment can trigger the release of Pt drug and Fe2/3+, which could induce the intracellular cascade reaction to generate sufficient •OH for ferroptosis therapy. Moreover, the released Pt drug can cause the apoptosis of tumor cells. Meanwhile, the encapsulated Fe3O4 nanoparticles can also be used for T2-weighted MRI of tumor. Both in vitro and in vivo results indicate that the reported Pt&Fe3O4@PP can efficiently inhibit cancer cell growth without causing significant systemic toxicity. Importantly, polypeptide vehicles could significantly reduce the side effect of free Pt drug in vivo and therefore improve the drug delivery efficacy. Our findings suggest that polypeptide-based theranostics with tumor-microenvironment-activatable cascade reaction have great potential in biomedical applications.

Polypeptide-Based Theranostics with Tumor-Microenvironment-Activatable Cascade Reaction for Chemo-ferroptosis Combination Therapy.

Poly(ethylene glycol)-mediated mineralization of metal-organic frameworks

We report the assembly of dual-responsive polypeptide nanoparticles loaded with indocyanine green (ICG) using a mesoporous silica (MS) templating method for photothermal and photodynamic therapy. P...

Dual-Stimuli-Responsive Polypeptide Nanoparticles for Photothermal and Photodynamic Therapy

Tunable assembly and disassembly of responsive supramolecular polymer brushes

Nanocarriers with responsibility and surface functionality of targeting molecules have been widely used to improve therapeutic efficiency. Hence, we report the assembly of pH-responsive and targeted polymer nanoparticles (NPs) composed of poly(2-(diisopropylamino)ethyl methacrylate) (PDPA) as the core and poly(carboxybetaine methacrylate) (PCBMA) as the shell, functionalized with cyclic peptides containing Arginine-Glycine-Aspartic acid-D-Phenylalanine-Lysine (RGD). The resulting polymer NPs (PDPA@PCBMA-RGD NPs) can maintain the pH-responsivity of PDPA (pKa ~6.5) and low-fouling property of PCBMA that significantly resist non-specific interactions with RAW 264.7 and HeLa cells. Meanwhile, PDPA@PCBMA-RGD NPs could specifically target αvβ3 integrin-expressed human glioblastoma (U87) cells. The pH-responsiveness and low-fouling properties of PDPA@PCBMA NPs are comparable to PDPA@poly(ethylene glycol) (PDPA@PEG) NPs, which indicates that PCBMA is an alternative to PEG for low-fouling coatings. The advantage of PDPA@PCBMA NPs lies in the presence of carboxyl groups on their surfaces for further modification (e.g., RGD functionalization for cell targeting). The reported polymer NPs represent a new carrier that have the potential for targeted therapeutic delivery.

Zhiliang Gao

Papers

Polypeptide-Based Theranostics with Tumor-Microenvironment-Activatable Cascade Reaction for Chemo-ferroptosis Combination Therapy.

Poly(ethylene glycol)-mediated mineralization of metal-organic frameworks

Dual-Stimuli-Responsive Polypeptide Nanoparticles for Photothermal and Photodynamic Therapy

Tunable assembly and disassembly of responsive supramolecular polymer brushes

Antifouling and pH-responsive poly(carboxybetaine)-based nanoparticles for tumor cell targeting