AMP-guided tumour-specific nanoparticle delivery via adenosine A1 receptor

Adenosine receptors in breast cancer

Adenosine receptors are important in the normal physiological function of cells and the pathogenesis of various cancer cells, including breast cancer cells. The activity of adenosine receptors in cancer cells is related to cell proliferation, angiogenesis, metastasis, immune system evasion, and interference with apoptosis. Considering the different roles of adenosine receptors in cancer cells, we intend to investigate the function of adenosine receptors and their biological pathways in breast cancer to improve understanding of therapeutically relevant signaling pathways.

Tumor Microenvironment Responsive CD8+ T Cells and Myeloid-Derived Suppressor Cells to Trigger CD73 Inhibitor AB680-Based Synergistic Therapy for Pancreatic Cancer

CD73 plays a critical role in the pathogenesis and immune escape in pancreatic ductal adenocarcinoma (PDAC). AB680, an exceptionally potent and selective inhibitor of CD73, is administered in an early clinical trial, in conjunction with gemcitabine and anti-PD-1 therapy, for the treatment of PDAC. Nevertheless, the specific therapeutic efficacy and immunoregulation within the microenvironment of AB680 monotherapy in PDAC have yet to be fully elucidated. In this study, AB680 exhibits a significant effect in augmenting the infiltration of responsive CD8+ T cells and prolongs the survival in both subcutaneous and orthotopic murine PDAC models. In parallel, it also facilitates chemotaxis of myeloid-derived suppressor cells (MDSCs) by tumor-derived CXCL5 in an AMP-dependent manner, which may potentially contribute to enhanced immunosuppression. The concurrent administration of AB680 and PD-1 blockade, rather than gemcitabine, synergistically restrain tumor growth. Notably, gemcitabine weakened the efficacy of AB680, which is dependent on CD8+ T cells. Finally, the supplementation of a CXCR2 inhibitor is validated to further enhance the therapeutic efficacy when combined with AB680 plus PD-1 inhibitor. These findings systematically demonstrate the efficacy and immunoregulatory mechanism of AB680, providing a novel, efficient, and promising immunotherapeutic combination strategy for PDAC.

Nanomedicine in cancer therapy

Cancer remains a highly lethal disease in the world. Currently, either conventional cancer therapies or modern immunotherapies are non-tumor-targeted therapeutic approaches that cannot accurately distinguish malignant cells from healthy ones, giving rise to multiple undesired side effects. Recent advances in nanotechnology, accompanied by our growing understanding of cancer biology and nano-bio interactions, have led to the development of a series of nanocarriers, which aim to improve the therapeutic efficacy while reducing off-target toxicity of the encapsulated anticancer agents through tumor tissue-, cell-, or organelle-specific targeting. However, the vast majority of nanocarriers do not possess hierarchical targeting capability, and their therapeutic indices are often compromised by either poor tumor accumulation, inefficient cellular internalization, or inaccurate subcellular localization. This Review outlines current and prospective strategies in the design of tumor tissue-, cell-, and organelle-targeted cancer nanomedicines, and highlights the latest progress in hierarchical targeting technologies that can dynamically integrate these three different stages of static tumor targeting to maximize therapeutic outcomes. Finally, we briefly discuss the current challenges and future opportunities for the clinical translation of cancer nanomedicines.

Advanced liposome and polymersome-based drug delivery systems: Considerations for physicochemical properties, targeting strategies and stimuli-sensitive approaches

Liposomes and polymersomes are colloidal vesicles that are self-assembled from lipids and amphiphilic polymers, respectively. Because of their ability to encapsulate both hydrophilic and hydrophobic therapeutics, they are of great interest in drug delivery research. Today, the applications of liposomes and polymersomes have expanded to a wide variety of complex therapeutic molecules, including nucleic acids, proteins and enzymes. Thanks to their chemical versatility, they can be tailored to different drug delivery applications to achieve maximum therapeutic index. This review article evaluates liposomes and polymersomes from a perspective that takes into account the physical and biological barriers that reduce the efficiency of the drug delivery process. In this context, the design approaches of liposomes and polymersomes are discussed with representative examples in terms of their physicochemical properties (size, shape, charge, mechanical), targeting strategies (passive and active) and response to different stimuli (pH, redox, enzyme, temperature, light, magnetic field, ultrasound). Finally, the challenges limiting the transition from laboratory to practice, recent clinical developments, and future perspectives are addressed.

Autonomous Treatment of Bacterial Infections in Vivo Using Antimicrobial Micro- and Nanomotors

The increasing resistance of bacteria to existing antibiotics constitutes a major public health threat globally. Most current antibiotic treatments are hindered by poor delivery to the infection site, leading to undesired off-target effects and drug resistance development and spread. Here, we describe micro- and nanomotors that effectively and autonomously deliver antibiotic payloads to the target area. The active motion and antimicrobial activity of the silica-based robots are driven by catalysis of the enzyme urease and antimicrobial peptides, respectively. These antimicrobial motors show micromolar bactericidal activity in vitro against different Gram-positive and Gram-negative pathogenic bacterial strains and act by rapidly depolarizing their membrane. Finally, they demonstrated autonomous anti-infective efficacy in vivo in a clinically relevant abscess infection mouse model. In summary, our motors combine navigation, catalytic conversion, and bactericidal capacity to deliver antimicrobial payloads to specific infection sites. This technology represents a much-needed tool to direct therapeutics to their target to help combat drug-resistant infections.

SERS tags derived from silver nanoparticles and aryl diazonium salts for cell Raman imaging

The surface functionalization of silver nanoparticles (NPs) by Raman reporters has stimulated a wide interest in recent years for the design of Surface-Enhanced Raman Spectroscopy (SERS) labels. However, silver NPs are prone to oxidation and aggregation, which strongly limits their applications. The design of stable SERS tags based on Ag NPs still represents a major challenge for Raman bioimaging. We address this issue herein by taking advantage of aryl diazonium salt chemistry to obtain stable Ag NPs functionalized by multifunctional polyaryl layers bearing different Raman reporters (-NO₂, -CN, -CCH). The resulting SERS-encoded Ag NPs were characterized by UV-vis absorption, transmission electron microscopy (TEM) and SERS. The formation of multilayers at the surface of Ag NPs gives access to new spectrally distinguishable SERS codes thus broadening the library of available Raman tags. Proof-of-concept Raman imaging experiments were performed on cancer cells (HeLa) after NP uptake, highlighting the large potentials of diazonium salt chemistry to design Ag NPs-based SERS labels for Raman bioimaging.

AMP functionalized curdlan nanoparticles as a siRNA carrier: Synthesis, characterization and targeted delivery via adenosine A2B receptor

Receptor-mediated endocytosis has been used for tissue targeted delivery of short interfering RNA (siRNA) drugs. Herein, we investigated adenosine receptor (AR) as a candidate for receptor-mediated siRNA internalization. We synthesized adenosine functionalized cationic curdlan derivatives (denote CuAMP polymers). One of these polymers, CuAMP4, efficiently delivered siRNA to breast cancer cells expressing high level of A_2B receptor. The internalization of siRNA loaded CuAMP4 by cancer cells was inhibited by free AMP as well as endocytosis inhibitors. Moreover, knockdown of A_2BR by siRNA, or pre-treatment of the cells with anti-A_2BR antibody, strongly inhibited the cellular uptake of CuAMP4. Our findings confirmed that A_2BR can be utilized for cell type specific siRNA delivery, and CuAMP4 NP may be a promising delivery system for cancer cell targeted delivery of therapeutic siRNAs.

Polarity control of DNA adsorption enabling the surface functionalization of CuO nanozymes for targeted tumor therapy

Nanomaterials with intrinsic catalytic activities (nanozyme) have drawn broad attention for various biomedical applications, with peroxidase-mimic nanozymes particularly attractive for cancer therapy due to their capability to catalyze the conversion of tumor-abundant H₂O₂ into more toxic hydroxyl radicals (˙OH) for effective tumor ablation. However, the facile surface modification of nanozymes for tumor-targeted delivery while retaining their catalytic activity remains a challenge. Here, we report an approach to functionalize the CuO nanozyme with DNA to enable targeted delivery and selective tumor destruction. We systematically studied the adsorption of DNA on the CuO surface, with special attention paid to the catalytic activity and DNA adsorption stability in the presence of various biological ligands. After gaining a fundamental understanding, a di-block DNA sequence was designed for adsorption on to the CuO surface, which allowed stable adsorption during in vivo circulation, passive accumulation into the tumor tissue, and the specific recognition of tumor cells, resulting in significant nanocatalytic tumor suppression in tumor xenograft mice models with no noticeable cytotoxicity. This work paves a way for the rational design of DNA-modified nanozymes for catalytic tumor therapy, and fundamentally, provides a new insight into the biointerface chemistry of CuO with DNA.

Ligand-Installed Nanocarriers toward Precision Therapy

Development of drug-delivery systems that selectively target neoplastic cells has been a major goal of nanomedicine. One major strategy for achieving this milestone is to install ligands on the surface of nanocarriers to enhance delivery to target tissues, as well as to enhance internalization of nanocarriers by target cells, which improves accuracy, efficacy, and ultimately enhances patient outcomes. Herein, recent advances regarding the development of ligand-installed nanocarriers are introduced and the effect of their design on biological performance is discussed. Besides academic achievements, progress on ligand-installed nanocarriers in clinical trials is presented, along with the challenges faced by these formulations. Lastly, the future perspectives of ligand-installed nanocarriers are discussed, with particular emphasis on their potential for emerging precision therapies.

Raman reporters derived from aryl diazonium salts for SERS encoded-nanoparticles

A new generation of surface-enhanced Raman scattering encoded-nanoparticles has been designed by combining aryl diazonium salt chemistry and gold nanoparticles.

iRGD-functionalized PEGylated nanoparticles for enhanced colon tumor accumulation and targeted drug delivery

AIM

To enhance the tumor accumulation and targeted drug delivery for colon cancer therapy, iRGD peptide was introduced to the surface of PEGylated camptothecin-loaded nanoparticles (NPs).

METHODS

Cellular uptake, targeting specificity, biodistribution and antitumor capacity were evaluated.

RESULTS

The functionalization of iRGD facilitated tumor accumulation and cellular uptake of NPs by Colon-26 cells. Furthermore, the resultant iRGD-PEG-NPs remarkably improved the therapeutic efficacy of camptothecin in vitro and in vivo by inducing a higher degree of tumor cell apoptosis compared with PEG-NPs.

CONCLUSION

iRGD-PEG-NP is a desired drug delivery system to facilitate the drug accumulation in orthotopic colon tumor tissues and further drug internalization by colon cancer cells.

Nanoparticles for radiooncology: Mission, vision, challenges

Cancer is one of the leading non-communicable diseases with highest mortality rates worldwide. About half of all cancer patients receive radiation treatment in the course of their disease. However, treatment outcome and curative potential of radiotherapy is often impeded by genetically and/or environmentally driven mechanisms of tumor radioresistance and normal tissue radiotoxicity. While nanomedicine-based tools for imaging, dosimetry and treatment are potential keys to the improvement of therapeutic efficacy and reducing side effects, radiotherapy is an established technique to eradicate the tumor cells. In order to progress the introduction of nanoparticles in radiooncology, due to the highly interdisciplinary nature, expertise in chemistry, radiobiology and translational research is needed. In this report recent insights and promising policies to design nanotechnology-based therapeutics for tumor radiosensitization will be discussed. An attempt is made to cover the entire field from preclinical development to clinical studies. Hence, this report illustrates (1) the radio- and tumor-biological rationales for combining nanostructures with radiotherapy, (2) tumor-site targeting strategies and mechanisms of cellular uptake, (3) biological response hypotheses for new nanomaterials of interest, and (4) challenges to translate the research findings into clinical trials.