Novel approaches for the preparation of magnetic nanogels via covalent bonding

Magnetic iron oxide nanogels for combined hyperthermia and drug delivery for cancer treatment

Hyperthermia and chemotherapy represent potential modalities for cancer treatments. However, hyperthermia can be invasive, while chemotherapy drugs often have severe side effects. Recent clinical investigations have underscored the potential synergistic efficacy of combining hyperthermia with chemotherapy, leading to enhanced cancer cell killing. In this context, magnetic iron oxide nanogels have emerged as promising candidates as they can integrate superparamagnetic iron oxide nanoparticles (IONPs), providing the requisite magnetism for magnetic hyperthermia, with the nanogel scaffold facilitating smart drug delivery. This review provides an overview of the synthetic methodologies employed in fabricating magnetic nanogels. Key properties and designs of these nanogels are discussed and challenges for their translation to the clinic and the market are summarised.

CuAAC ensembled 1,2,3-triazole linked nanogels for targeted drug delivery: a review

Copper(i) catalyzed alkyne azide cycloaddition (CuAAC), the quintessential example of 'click chemistry', provides an adaptable and adequate platform for the synthesis of nanogels for sustained drug release at targeted sites because of their better biocompatibility. The coupling of drugs, carried out via various synthetic routes including CuAAC, into long-chain polymeric forms like nanogels has exhibited considerable assurance in therapeutic advancements and intracellular drug delivery due to the progression of water solubility, evacuation of precocious drug release, and improved upthrust of the pharmacokinetics of the nanogels, thereby rendering them as better and efficient drug carriers. The inefficiency of drug transmission to the target areas due to the resistance of complex biological barriers in vivo is a major hurdle that impedes the therapeutic translation of nanogels. This review compiles the data of nanogels synthesized specifically via CuAAC 'click' methodology, as scaffolds for targeted drug delivery and their assimilation into nanomedicine. In addition, it elaborates the ability of CuAAC to graft specific moieties and conjugating biomolecules like proteins and growth factors, onto orthogonally functionalized polymer chains with various chemical groups resulting in nanogels that are not only more appealing but also more effective at delivering drugs, thereby enhancing their site-specific target approach and initiating selective therapies.

Polymeric Delivery of Therapeutic Nucleic Acids

The advent of genome editing has transformed the therapeutic landscape for several debilitating diseases, and the clinical outlook for gene therapeutics has never been more promising. The therapeutic potential of nucleic acids has been limited by a reliance on engineered viral vectors for delivery. Chemically defined polymers can remediate technological, regulatory, and clinical challenges associated with viral modes of gene delivery. Because of their scalability, versatility, and exquisite tunability, polymers are ideal biomaterial platforms for delivering nucleic acid payloads efficiently while minimizing immune response and cellular toxicity. While polymeric gene delivery has progressed significantly in the past four decades, clinical translation of polymeric vehicles faces several formidable challenges. The aim of our Account is to illustrate diverse concepts in designing polymeric vectors towards meeting therapeutic goals of in vivo and ex vivo gene therapy. Here, we highlight several classes of polymers employed in gene delivery and summarize the recent work on understanding the contributions of chemical and architectural design parameters. We touch upon characterization methods used to visualize and understand events transpiring at the interfaces between polymer, nucleic acids, and the physiological environment. We conclude that interdisciplinary approaches and methodologies motivated by fundamental questions are key to designing high-performing polymeric vehicles for gene therapy.

In Situ Dendritic Cell Vaccine for Effective Cancer Immunotherapy

A cancer vaccine is an important form of immunotherapy. Given their effectiveness for antigen processing and presentation, dendritic cells (DCs) have been exploited in the development of a therapeutic vaccine. Herein, a versatile polymersomal nanoformulation that enables generation of tumor-associated antigens (TAAs) and simultaneously serves as adjuvant for an in situ DC vaccine is reported. The chimeric cross-linked polymersome (CCPS) is acquired from self-assembly of a triblock copolymer, polyethylene glycol-poly(methyl methyacrylate- co-2-amino ethyl methacrylate (thiol/amine))-poly 2-(dimethylamino)ethyl methacrylate (PEG-P(MMA- co-AEMA (SH/NH₂)-PDMA). CCPS can encapsulate low-dose doxorubicin hydrochloride (DOX) to induce immunogenic cell death (ICD) and 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH), a photosensitizer to facilitate photodynamic therapy (PDT) for reactive oxygen species (ROS) generation. This combination is able to enhance the population of TAAs and DC recruitment, eliciting an immune response cascade. In addition, CCPS with primary and tertiary amines act as adjuvant, both of which can stimulate DCs recruited to form an in situ DC vaccine after combination with TAAs for MC38 colorectal cancer treatment. In vivo results indicate that the all-in-one polymersomal nanoformulation (CCPS/HPPH/DOX) increases mature DCs in tumor-draining lymph nodes (tdLNs) and CD8⁺ T cells in tumor tissues to inhibit primary and distant MC38 tumor growth following a single intravenous injection with a low dose of DOX and HPPH.