Maleimide as the PEG end-group promotes macrophage-targeted drug delivery of PEGylated nanoparticles in vivo by enhancing interaction with circulating erythrocytes

Enhancing ovarian cancer treatment with maleimide-modified Pt(IV) prodrug nanoparticles

The limitations of platinum in ovarian cancer therapy, such as poor solubility and significant side effects, often lead to suboptimal therapeutic outcome and mortality. In this study, we have developed a novel approach utilizing biodegradable polymeric nanoparticles as a drug delivery system (NDDS), loaded with advanced platinum (IV) (Pt(IV)) prodrugs. A key feature of our approach is the enhancement of nanoparticles with maleimide, a modification hypothesized to significantly boost tumor tissue accumulation. When tested in mouse models of orthotopic and peritoneal metastasis ovarian cancer, these maleimide-modified nanoparticles are anticipated to show preferential accumulation in tumor tissues, enhancing therapeutic efficiency and minimizing systemic drug exposure. Our findings demonstrate that the maleimide-modified Pt(IV)-loaded NDDSs significantly reduce tumor burden in comparison to traditional cisplatin therapy, while simultaneously reducing adverse side effects. This leads to markedly improved survival rates in models of peritoneal metastasis ovarian cancer, offering a promising new direction in the treatment of this challenging disease.

PD-L1 siRNA hitched polyethyleneimine-elastase constituting nanovesicle induces tumor immunogenicity and PD-L1 silencing for synergistic antitumor immunotherapy

BACKGROUND

PD-1/PD-L1 blockade has become a powerful method to treat malignant tumors. However, a large proportion of patients still do not benefit from this treatment, due to low tumor immunogenicity and low tumor penetration of the agents. Recently, neutrophil elastase has been shown to induce robust tumor immunogenicity, while the insufficient enzyme activity at the tumor site restricted its anti-tumor application. Here, we designed polyethyleneimine-modified neutrophil elastase (PEI-elastase) loaded with PD-L1small interfering RNA (PD-L1 siRNA) for improving enzymatic activity and delivering siRNA to tumor, which was expected to solve the above-mentioned problems.

RESULTS

We first demonstrated that PEI-elastase possessed high enzymatic activity, which was also identified as an excellent gene-delivery material. Then, we synthesized anti-tumor lipopolymer (P-E/S Lip) by encapsulating PEI-elastase and PD-L1siRNA with pH-responsive anionic liposomes. The P-E/S Lip could be rapidly cleaved in tumor acidic environment, leading to exposure of the PEI-elastase/PD-L1 siRNA. Consequently, PEI-elastase induced powerful tumor immunogenicity upon direct tumor killing with minimal toxicity to normal cells. In parallel, PEI-elastase delivered PD-L1siRNA into the tumor and reduced PD-L1 expression. Orthotopic tumor administration of P-E/S Lip not only attenuated primary tumor growth, but also produced systemic anti-tumor immune response to inhibit growth of distant tumors and metastasis. Moreover, intravenous administration of P-E/S Lip into mice bearing subcutaneous tumors leaded to an effective inhibition of established B16-F10 tumor and 4T1 tumor, with histological analyses indicating an absence of detectable toxicity.

CONCLUSIONS

In our study, a protease-based nanoplatform was used to cooperatively provoke robust tumor immunogenicity and down-regulate PD-L1 expression, which exhibited great potential as a combination therapy for precisely treating solid tumors.

Engineering of Erythrocytes as Drug Carriers for Therapeutic Applications

Erythrocytes, also known as red blood cells (RBCs), have garnered considerable attention as potential carriers for drug delivery, owing to their inherent properties such as biocompatibility, biodegradability, and prolonged circulation half-life. This paper presents a comprehensive overview of the role of erythrocytes in drug delivery, elucidating recent advancements in delivering a diverse array of therapeutic agents, including small molecules, nucleic acids, antibodies, protein enzymes, and nanoparticles. Two primary strategies for encapsulating drugs within erythrocytes are systematically discussed: internal loading and surface loading. Each strategy offers distinct advantages in terms of drug stability and release kinetics. Notably, the utilization of erythrocyte membrane camouflaged nanocarriers holds promise for enhancing the biocompatibility of conventional nanoparticles and facilitating targeted drug delivery. Furthermore, the broad spectrum of biomedical applications of erythrocyte-based drug delivery systems are examined, ranging from cancer treatment to diabetes management, thrombosis prevention, and immunotherapy. This review provides a comprehensive evaluation of current technologies in erythrocyte-loaded drug delivery, highlighting the strengths, weaknesses, and future directions for advancing therapeutic interventions in various disease contexts.

Selenium promotes immunogenic radiotherapy against cervical cancer metastasis through evoking P53 activation

Radiotherapy is still the recommended treatment for cervical cancer. However, radioresistance and radiation-induced side effects remain one of the biggest clinical problems. Selenium (Se) has been confirmed to exhibit radiation-enhancing effects for cancer treatment. However, Se species dominate the biological activities and which form of Se possesses better radiosensitizing properties and radiation safety remains elusive. Here, different Se species (the valence state of Se ranged from - 2, 0, +4 to + 6) synergy screen was carried out to identify the potential radiosensitizing effects and radiation safety of Se against cervical cancer. We found that the therapeutic effects varied with the changes in the Se valence state. Sodium selenite (+4) displayed strong cancer-killing effects but also possessed severe cytotoxicity. Sodium selenate (+6) neither enhanced the killing effects of X-ray nor possessed anticancer activity by its alone treatment. Although nano-selenium (0), especially Let-SeNPs, has better radiosensitizing activity, the - 2 organic Se, such as selenadiazole derivative SeD (-2) exhibited more potent anticancer effects and possessed a higher safe index. Overall, the selected Se drugs were able to synergize with X-ray to inhibit cell growth, clone formation, and cell migration by triggering G2/M phase arrest and apoptosis, and SeD (-2) was found to exhibit more potent enhancing capacity. Further mechanism studies showed that SeD mediated p53 pathway activation by inducing DNA damage through promoting ROS production. Additionally, SeD combined with X-ray therapy can induce an anti-tumor immune response in vivo. More importantly, SeD combined with X-ray significantly inhibited the liver metastasis of tumor cells and alleviated the side effects caused by radiation therapy in tumor-bearing mice. Taken together, this study demonstrates the radiosensitization and radiation safety effects of different Se species, which may shed light on the application of such Se-containing drugs serving as side effects-reducing agents for cervical cancer radiation treatment.

Advancing cell surface modification in mammalian cells with synthetic molecules

Biological cells, being the fundamental entities of life, are widely acknowledged as intricate living machines. The manipulation of cell surfaces has emerged as a progressively significant domain of investigation and advancement in recent times. Particularly, the alteration of cell surfaces using meticulously crafted and thoroughly characterized synthesized molecules has proven to be an efficacious means of introducing innovative functionalities or manipulating cells. Within this realm, a diverse array of elegant and robust strategies have been recently devised, including the bioorthogonal strategy, which enables selective modification. This review offers a comprehensive survey of recent advancements in the modification of mammalian cell surfaces through the use of synthetic molecules. It explores a range of strategies, encompassing chemical covalent modifications, physical alterations, and bioorthogonal approaches. The review concludes by addressing the present challenges and potential future opportunities in this rapidly expanding field.