Bacteriomimetic poly-γ-glutamic acid surface coating for hemocompatibility and safety of nanomaterials

Apelin-13-Loaded Macrophage Membrane-Encapsulated Nanoparticles for Targeted Ischemic Stroke Therapy via Inhibiting NLRP3 Inflammasome-Mediated Pyroptosis

Purpose

Ischemic stroke is a refractory disease wherein the reperfusion injury caused by sudden restoration of blood supply is the main cause of increased mortality and disability. However, current therapeutic strategies for the inflammatory response induced by cerebral ischemia-reperfusion (I/R) injury are unsatisfactory. This study aimed to develop a functional nanoparticle (MM/ANPs) comprising apelin-13 (APNs) encapsulated in macrophage membranes (MM) modified with distearoyl phosphatidylethanolamine-polyethylene glycol-RVG29 (DSPE-PEG-RVG29) to achieve targeted therapy against ischemic stroke.

Methods

MM were extracted from RAW264.7. PLGA was dissolved in dichloromethane, while Apelin-13 was dissolved in water, and CY5.5 was dissolved in dichloromethane. The precipitate was washed twice with ultrapure water and then resuspended in 10 mL to obtain an aqueous solution of PLGA nanoparticles. Subsequently, the cell membrane was evenly dispersed homogeneously and mixed with PLGA-COOH at a mass ratio of 1:1 for the hybrid ultrasound. DSPE-PEG-RVG29 was added and incubated for 1 h to obtain MM/ANPs.

Results

In this study, we developed a functional nanoparticle delivery system (MM/ANPs) that utilizes macrophage membranes coated with DSPE-PEG-RVG29 peptide to efficiently deliver Apelin-13 to inflammatory areas using ischemic stroke therapy. MM/ANPs effectively cross the blood-brain barrier and selectively accumulate in ischemic and inflamed areas. In a mouse I/R injury model, these nanoparticles significantly improved neurological scores and reduced infarct volume. Apelin-13 is gradually released from the MM/ANPs, inhibiting NLRP3 inflammasome assembly by enhancing sirtuin 3 (SIRT3) activity, which suppresses the inflammatory response and pyroptosis. The positive regulation of SIRT3 further inhibits the NLRP3-mediated inflammation, showing the clinical potential of these nanoparticles for ischemic stroke treatment. The biocompatibility and safety of MM/ANPs were confirmed through in vitro cytotoxicity tests, blood-brain barrier permeability tests, biosafety evaluations, and blood compatibility studies.

Conclusion

MM/ANPs offer a highly promising approach to achieve ischemic stroke-targeted therapy inhibiting NLRP3 inflammasome-mediated pyroptosis.

Safety and photochemotherapeutic application of poly(γ-glutamic acid)-based biopolymeric nanoparticle

The safety of nanomaterials, a crucial consideration for clinical translation, is enhanced by using building blocks that are biologically nontoxic. Here, we used poly(γ-glutamic acid) (γ-PGA) and dopamine as building blocks of polymeric nanomaterials for carrying hydrophobic anticancer drugs. The introduction of phenylalanine onto γ-PGA enabled the resulting amphiphilic derivative of γ-PGA acid to self-assemble in the presence of the anticancer drug paclitaxel (PTX) to form PTX-encapsulated micelles. The surfaces of PTX-loaded micelles were then coated with polymerized dopamine (PDA). The PDA-coated, amphiphilic γ-PGA-based micelles (AM) carrying PTX (PDA/AM/P) exerted near-infrared-responsive photothermal effects. Near-infrared irradiation of cancer cells treated with PDA/AM/P nanoparticles produced a greater anticancer effect than that observed in other treatment groups, indicating a synergistic effect. Intravenous administration of PDA/AM/P completely ablated tumors and prevented their recurrence. Notably, the in vivo safety profile of PDA/AM/P nanoparticles allowed PTX to be delivered at a 3.6-fold higher dose than was possible with PTX solubilized in surfactant, and circumvented the side effects of the surfactant. These results support the multifunctional potential of PDA/AM for the delivery of various hydrophobic drugs and imaging dyes for safe translation of nanomaterials into the clinic.

A Systematic Review and Critical Analysis of the Role of Graphene-Based Nanomaterialsin Cancer Theranostics

Many graphene-based materials (GBNs) applied to therapy and diagnostics (theranostics) in cancer have been developed. Most of them are hybrid combinations of graphene with other components (e.g, drugs or other bioactives, polymers, and nanoparticles) aiming toward a synergic theranostic effect. However, the role of graphene in each of these hybrids is sometimes not clear enough and the synergic graphene effect is not proven. The objective of this review is to elaborate on the role of GBNs in the studies evaluated and to compare the nanoformulations in terms of some of their characteristics, such as therapeutic outcomes and toxicity, which are essential features for their potential use as bionanosystems. A systematic review was carried out using the following databases: PubMed, Scopus, and ISI Web of Science (2013⁻2018). Additional studies were identified manually by consulting the references list of relevant reviews. Only English papers presenting at least one strategy for cancer therapy and one strategy for cancer diagnostics, and that clearly show the role of graphene in theranostics, were included. Data extraction and quality assessment was made by reviewer pairings. Fifty-five studies met the inclusion criteria, but they were too heterogeneous to combine in statistical meta-analysis. Critical analysis and discussion of the selected papers are presented.