Photothermal-triggered dendrimer nanovaccines boost systemic antitumor immunity

Multifunctional hydrogels based on photothermal therapy: A prospective platform for the postoperative management of melanoma

Preventing the recurrence of melanoma after surgery and accelerating wound healing are among the most challenging aspects of melanoma management. Photothermal therapy has been widely used to treat tumors and bacterial infections and promote wound healing. Owing to its efficacy and specificity, it may be used for postoperative management of tumors. However, its use is limited by the uncontrollable distribution of photosensitizers and the likelihood of damage to the surrounding normal tissue. Hydrogels provide a moist environment with strong biocompatibility and adhesion for wound healing owing to their highly hydrophilic three-dimensional network structure. In addition, these materials serve as excellent drug carriers for tumor treatment and wound healing. It is possible to combine the advantages of both of these agents through different loading modalities to provide a powerful platform for the prevention of tumor recurrence and wound healing. This review summarizes the design strategies, research progress and mechanism of action of hydrogels used in photothermal therapy and discusses their role in preventing tumor recurrence and accelerating wound healing. These findings provide valuable insights into the postoperative management of melanoma and may guide the development of promising multifunctional hydrogels for photothermal therapy.

Dendritic nanoparticles for immune modulation: a potential next-generation nanocarrier for cancer immunotherapy

Immune activation, whether occurring from direct immune checkpoint blockade or indirectly as a result of chemotherapy, is an approach that has drastically impacted the way we treat cancer. Utilizing patients' own immune systems for anti-tumor efficacy has been translated to robust immunotherapies; however, clinically significant successes have been achieved in only a subset of patient populations. Dendrimers and dendritic polymers have recently emerged as a potential nanocarrier platform that significantly improves the therapeutic efficacy of current and next-generation cancer immunotherapies. In this paper, we highlight the recent progress in developing dendritic polymer-based therapeutics with immune-modulating properties. Specifically, dendrimers, dendrimer hybrids, and dendronized copolymers have demonstrated promising results and are currently in pre-clinical development. Despite their early stage of development, these nanocarriers hold immense potential to make profound impact on cancer immunotherapy and combination therapy. This overview provides insights into the potential impact of dendrimers and dendron-based polymers, offering a preview of their potential utilities for various aspects of cancer treatment.

Structural and Property Characterizations of Dual-Responsive Core-Shell Tecto Dendrimers for Tumor Penetration and Gene Delivery Applications

Core-shell tecto dendrimers (CSTDs) with excellent physicochemical properties and good tumor penetration and gene transfection efficiency have been demonstrated to have the potential to replace high-generation dendrimers in biomedical applications. However, their characterization and related biological properties of CSTDs for enhanced tumor penetration and gene delivery still lack in-depth investigation. Herein, three types of dual-responsive CSTDs are designed for thorough physicochemical characterization and investigation of their tumor penetration and gene delivery efficiency. Three types of CSTDs are prepared through phenylborate ester bonds of phenylboronic acid (PBA)-decorated generation 5 (G5) poly(amidoamine) (PAMAM) dendrimers as cores and monose (galactose, glucose, or mannose)-conjugated G3 PAMAM dendrimers as shells and thoroughly characterized via NMR and other techniques. It is shown that the produced CSTDs display strong correlation signals between the PBA and monose protons, similar hydrodynamic diameters, and dual reactive oxygen species- and pH-responsivenesses. The dual-responsive CSTDs are proven to have structure-dependent tumor penetration property and gene delivery efficiency in terms of small interference RNA for gene silencing and plasmid DNA for gene editing, thus revealing a great potential for different biomedical applications.

Proton Sponge Nanocomposites for Synergistic Tumor Elimination via Autophagy Inhibition-Promoted Cell Apoptosis and Macrophage Repolarization-Enhanced Immune Response

Cytoprotective autophagy and an immunosuppressive tumor microenvironment (TME) are two positive promoters for tumor proliferation and metastasis that severely hinder therapeutic efficacy. Inhibiting autophagy and reconstructing TME toward macrophage activation simultaneously are of great promise for effective tumor elimination, yet are still a huge challenge. Herein, a kind of dendrimer-based proton sponge nanocomposites was designed and constructed for tumor chemo/chemodynamic/immunotherapy through autophagy inhibition-promoted cell apoptosis and macrophage repolarization-enhanced immune response. These obtained nanocomposites contain a proton sponge G5AcP dendrimer, a Fenton-like agent Cu(II), and chemical drug doxorubicin (DOX). When accumulated in tumor regions, G5AcP can act as an immunomodulator to realize deacidification-promoted macrophage repolarization toward antitumoral type, which then secretes inflammatory cytokines to activate T cells. They also regulate intracellular lysosomal pH to inhibit cytoprotective autophagy. The released Cu(II) and DOX can induce aggravated damage through a Fenton-like reaction and chemotherapeutic effect in this autophagy-inhibition condition. Tumor-associated antigens are released from these dying tumor cells to promote the maturity of dendritic cells, further activating T cells. Effective tumor elimination can be achieved by this dendrimer-based therapeutic strategy, providing significant guidance for the design of a promising antitumor nanomedicine.

Nanocodelivery of an NIR photothermal agent and an acid-responsive TLR7 agonist prodrug to enhance cancer photothermal immunotherapy and the abscopal effect

The immunosuppressive tumor microenvironment (TME) greatly limits the actual outcome of immunotherapy. Therefore, it is urgent to develop appropriate strategies to reshape the TME and ultimately induce a strong immune response. Here, we developed a dual-functional liposome loaded with the photothermal agent IR808 near the infrared region (NIR) and Toll-like-receptor-7 (TLR7) agonist loxoribine prodrug (Lipo@IR808@Loxo) to achieve NIR light-triggered photothermal therapy (PTT) and the targeted delivery of immune adjuvants. Under NIR irradiation, Lipo@IR808@Loxo could greatly improve the efficiency of PTT to directly kill tumor cells and release tumor-associated antigens, which could work together with loaded loxoribine to relieve the immunosuppressive TME, effectively promoting the activation of antigen-presenting cells and subsequent antigen presentation. In this way, Lipo@IR808@Loxo could act as an in situ therapeutic cancer vaccine, eventually inducing a potent antitumor T-cell response. When further combined with immune checkpoint blockade, Lipo@IR808@Loxo-mediated photothermal immunotherapy could not only eliminate the primary tumors but also inhibit the growth of distant tumors, thus enhancing the abscopal effect.

Recent advances in multifunctional dendrimer-based complexes for cancer treatment

The application of nanotechnology in biological and medical fields have resulted in the creation of new devices, supramolecular systems, structures, complexes, and composites. Dendrimers are relatively new nanotechnological polymers with unique features; they are globular in shape, with a topological structure formed by monomeric subunit branches diverging to the sides from the central nucleus. This review analyzes the main features of dendrimers and their applications in biology and medicine regarding cancer treatment. Dendrimers have applications that include drug and gene carriers, antioxidant agents, imaging agents, and adjuvants, but importantly, dendrimers can create complex nanosized constructions that combine features such as drug/gene carriers and imaging agents. Dendrimer-based nanosystems include different metals that enhance oxidative stress, polyethylene glycol to provide biosafety, an imaging agent (a fluorescent, radioactive, magnetic resonance imaging probe), a drug or/and nucleic acid that provides a single or dual action on cells or tissues. One of major benefit of dendrimers is their easy release from the body (in contrast to metal nanoparticles, fullerenes, and carbon nanotubes), allowing the creation of biosafe constructions. Some dendrimers are already clinically approved and are being used as drugs, but many nanocomplexes are currently being studied for clinical practice. In summary, dendrimers are very useful tool in the creation of complex nanoconstructions for personalized nanomedicine. This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Nano-Topographically Guided, Biomineralized, 3D-Printed Polycaprolactone Scaffolds with Urine-Derived Stem Cells for Promoting Bone Regeneration

Currently, biomineralization is widely used as a surface modification approach to obtain ideal material surfaces with complex hierarchical nanostructures, morphologies, unique biological functions, and categorized organizations. The fabrication of biomineralized coating for the surfaces of scaffolds, especially synthetic polymer scaffolds, can alter surface characteristics, provide a favorable microenvironment, release various bioactive substances, regulate the cellular behaviors of osteoblasts, and promote bone regeneration after implantation. However, the biomineralized coating fabricated by immersion in a simulated body fluid has the disadvantages of non-uniformity, instability, and limited capacity to act as an effective reservoir of bioactive ions for bone regeneration. In this study, in order to promote the osteoinductivity of 3D-printed PCL scaffolds, we optimized the surface biomineralization procedure by nano-topographical guidance. Compared with biomineralized coating constructed by the conventional method, the nano-topographically guided biomineralized coating possessed more mineral substances and firmly existed on the surface of scaffolds. Additionally, nano-topographically guided biomineralized coating possessed better protein adsorption and ion release capacities. To this end, the present work also demonstrated that nano-topographically guided biomineralized coating on the surface of 3D-printed PCL scaffolds can regulate the cellular behaviors of USCs, guide the osteogenic differentiation of USCs, and provide a biomimetic microenvironment for bone regeneration.

Manganese Dioxide-Entrapping Dendrimers Co-Deliver Protein and Nucleotide for Magnetic Resonance Imaging-Guided Chemodynamic/Starvation/Immune Therapy of Tumors

Development of a nanoscale drug delivery system that can simultaneously exert efficient tumor therapeutic efficacy while creating the desired antitumor immune responses is still challenging. Herein, we report the use of a manganese dioxide (MnO2)-entrapping dendrimer nanocarrier to codeliver glucose oxidase (GOx) and cyclic GMP-AMP (cGAMP), an agonist of the stimulator of interferon genes (STING) for improved tumor chemodynamic/starvation/immune therapy. Methoxy poly(ethylene glycol) (mPEG)- and phenylboronic acid (PBA)-modified generation 5 (G5) poly(amidoamine) dendrimers were first synthesized and then entrapped with MnO2 nanoparticles (NPs) to generate the hybrid MnO2@G5-mPEG-PBA (MGPP) NPs. The created MGPP NPs with an MnO2 core size of 2.8 nm display efficient glutathione depletion ability, and a favorable Mn2+ release profile under a tumor microenvironment mimetic condition to enable Fenton-like reaction and T1-weighted magnetic resonance (MR) imaging. We show that the MGPP-mediated GOx delivery facilitates enhanced chemodynamic/starvation therapy of cancer cells in vitro, and further codelivery of cGAMP can effectively trigger immunogenic cell death (ICD) to strongly promote the maturation of dendritic cells. In a bilateral mouse colorectal tumor model, the dendrimer delivery nanosystem elicits a potent antitumor performance with a strong abscopal effect, greatly improving the overall mouse survival rate. Importantly, the dendrimer-mediated codelivery not only allows the coordination of Mn2+ with GOx and cGAMP for respective chemodynamic/starvation-triggered ICD and augmented STING activation to boost systemic antitumor immune responses, but also enables T1-weighted tumor MR imaging, potentially serving as a promising nanoplatform for enhanced antitumor therapy with desired immune responses.

Hyperbranched Polymer-Based Vaccines for Cancer Immunotherapy

Recently, several immunotherapeutic strategies are extensively studied and entered clinical investigation, suggesting their potential to lead a new generation of cancer therapy. Particularly, a cancer vaccine that combines tumor-associated antigens and immune adjuvants with a nanocarrier holds huge promise for inducing specific antitumor immune responses. Hyperbranched polymers, such as dendrimers and branched polyethylenimine (PEI) possessing abundant positively charged amine groups and inherent proton sponge effect are ideal carriers of antigens. Much effort is devoted to design dendrimer/branched PEI-based cancer vaccines. Herein, the recent advances in the design of dendrimer/branched PEI-based cancer vaccines for immunotherapy are reviewed. The future perspectives with regard to the development of dendrimer/branched PEI-based cancer vaccines are also briefly discussed.