Hybrid nanogels with unique designs for improved tumor theranostics

One stone, many birds: Recent advances in functional nanogels for cancer nanotheranostics

Inspired by the development of nanomedicine and nanotechnology, more and more possibilities in cancer theranostic have been provided in the last few years. Emerging therapeutic modalities like starvation therapy, chemodynamic therapy, and tumor oxygenation have been integrated with diagnosis, giving a plethora of theranostic nanoagents. Among all of them, nanogels (NGs) show superiority benefiting from their unique attributes: high stability, high water-absorption, large specific surface area, mechanical strength, controlled responsiveness, and high encapsulation capacity. There have been a vast number of investigations supporting various NGs combining drug delivery and multiple bioimaging techniques, encompassing photothermal imaging, photoacoustic imaging, fluorescent imaging, ultrasound imaging, magnetic resonance imaging, and computed tomography. This review summarizes recent advances in functional NGs for theranostic nanomedicine and discusses the challenges and future perspectives of this fast-growing field. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Dendrimer-Based Nanogels for Cancer Nanomedicine Applications

Recent advances in the field of nanotechnology bring an alternative approach to personalized medicine in cancer treatment. Nanogels (NGs) are among the nanosized superconstructs composed of amphiphilic or hydrophilic polymer networks. The design of different types of biodegradable polymer-based NGs in various biomedical applications has received extensive attention, due to their unique physicochemical properties such as highly porous structure, stimuli-responsiveness, and mimicking of some biological properties. In this review, we concisely surveyed the synthesis of dendrimer-based NGs synthesized via different methods including covalent conjugation, inverse nanoprecipitation, physical cross-linking, or self-assembly for various cancer nanomedicine applications, particularly for drug delivery, gene delivery, photothermal therapy, and combination therapy, as well as for biological imaging-guided chemotherapy. Additionally, we provide herein future perspective toward the new design of dendrimer-based NGs for different cancer nanomedicine uses.

Macrophage Membrane-Camouflaged Responsive Polymer Nanogels Enable Magnetic Resonance Imaging-Guided Chemotherapy/Chemodynamic Therapy of Orthotopic Glioma

Development of innovative nanomedicine formulations to traverse the blood-brain barrier (BBB) for effective theranostics of glioma remains a great challenge. Herein, we report the creation of macrophage membrane-camouflaged multifunctional polymer nanogels coloaded with manganese dioxide (MnO₂) and cisplatin for magnetic resonance (MR) imaging-guided chemotherapy/chemodynamic therapy (CDT) of orthotopic glioma. Redox-responsive poly(N-vinylcaprolactam) (PVCL) nanogels (NGs) formed via precipitation polymerization were in situ loaded with MnO₂ and physically encapsulated with cisplatin to have a mean size of 106.3 nm and coated with macrophage membranes to have a good colloidal stability. The generated hybrid NGs display dual pH- and redox-responsive cisplatin and Mn(II) release profiles and can deplete glutathione (GSH) rich in tumor microenvironment through reaction with disulfide-containing cross-linkers within the NGs and MnO₂. The thus created Mn(II) enables enhanced CDT through a Fenton-like reaction and T₁-weighted MR imaging, while the loaded cisplatin not only exerts its chemotherapy effect but also promotes the reactive oxygen species generation to enhance the CDT efficacy. Importantly, the macrophage membrane coating rendered the hybrid NGs with prolonged blood circulation time and ability to traverse BBB for specific targeted chemotherapy/CDT of orthotopic glioma. Our study demonstrates a promising self-adaptive and cooperative NG-based nanomedicine platform for highly efficient theranostics of glioma, which may be extended to tackle other difficult cancer types.