Polyelectrolyte-coated liposomes microfluidically assembled in one-step for enhancing cell endocytosis and in-vivo immune responses

To enhance the cellular uptake of liposomes, we prepared conventional liposomes with targeting molecules and surface-charged liposomes and evaluated their potential as nano-carriers and vaccine adjuvants by comparing their endocytosis efficiencies using immune cells. Surface-charged liposomes were synthesized via a one-step microfluidic method, which provided a novel, simple, fast, and highly reproducible method for preparing liposomes. Flow cytometry revealed that cationic polyelectrolyte-coated liposomes exhibited higher endocytosis efficiencies (of up to a factor of 100) in A774A.1 cells and JAWs II cells compared with uncoated liposomes or those coated with anionic polyelectrolytes. Positively charged liposomes exhibited some cytotoxicity at quaternary-chitosan coating concentrations higher than 6 mg/mL; however, significantly lower cytotoxicities (by a factor of almost ten) were obtained by protein mixing. Furthermore, BALB/c mice vaccinated with a mixture of Anthrax vaccine adsorbed (AVA) and quaternary chitosan-coated liposomes showed faster and stronger anti-PA IgG inductions compared to those vaccinated with AVA alone, with titers positively correlating with the amount of cationic liposome used. This finding clearly reveals that quaternary chitosan-coated liposomes act as both nano-carriers and vaccine adjuvants that significantly enhance in-vivo immune responses to vaccines with low immunogenicities.

Functional exosomes modified with chitosan effectively alleviate anthracycline-induced cardiotoxicity

Anthracyclines belong to a class of anti-tumor antibiotics, and their severe cardiotoxicity significantly limits their clinical use. Exosomes play key roles in intercellular communication, characterized by high biocompatibility and specific tissue and organ homing effects. In this study, doxorubicin, an anthracycline anticancer drug widely used in clinical chemotherapy, was selected as a model drug. To address the significant cardiotoxicity associated with doxorubicin, tumor exosomes are utilized as drug carriers. The homing effect of autologous exosomes enhances drug uptake by tumor cells and reduces cardiotoxicity. To enhance the stability of exosomes, improve therapeutic effectiveness, and reduce toxic side effects, chitosan was utilized to modify the surface of exosomes. Chitosan has a specific anti-tumor effect because it can target the CD44 receptor of tumor stem cells and interact with tumor cells through charge adsorption. Through in vitro cell experiments, in vivo pharmacokinetic experiments, and an in situ ectopic nude mouse tumor model, the study demonstrated that chitosan-modified tumor exosomes significantly alleviated the severe cardiotoxicity of doxorubicin, while also showing remarkable anti-tumor efficacy. This study introduces a novel approach to reduce the adverse side effects of anthracycline chemotherapeutic drugs and presents a highly promising nanocarrier delivery system.

Role and Merits of Green Based Nanocarriers in Cancer Treatment

Simple Summary

The use of chemotherapy drugs against tumours is associated with various drawbacks such as poor solubility, low stability, high toxicity, lack of selectivity and rapid clearance. Nanocarriers can improve the safety and efficiency of drugs by increasing their solubility, enhance their circulation time and improve their uptake into cancer cells. Natural materials can be incorporated in the fabrication of nanocarriers as a substitute to synthetic ingredients. Several studies developed different types of green based nanocarriers using materials obtained from plant or microbial sources such as polysaccharides and polyphenols without the need of toxic chemicals in the synthesis. The green components can have many roles for example as mechanical support, trigger pH response for drug release, or act as a targeting ligand. The inclusion of these green components will support the cost effective and feasible large-scale production of nanocarriers with minimum negative impact on the environment.

Abstract

The use of nanocarriers for biomedical applications has been gaining interests from researchers worldwide for the delivery of therapeutics in a controlled manner. These “smart” vehicles enhance the dissolution and the bioavailability of drugs and enable their delivery to the target site. Taking the potential toxicity into consideration, the incorporation of natural “green” materials, derived from plants or microbial sources, in the nanocarriers fabrication, improve their safety and biocompatibility. These green components can be used as a mechanical platform or as targeting ligand for the payload or can play a role in the synthesis of nanoparticles. Several studies reported the use of green based nanocarriers for the treatment of diseases such as cancer. This review article provides a critical analysis of the different types of green nanocarriers and their synthesis mechanisms, characterization, and their role in improving drug delivery of anticancer drugs to achieve precision cancer treatment. Current evidence suggests that green-based nanocarriers can constitute an effective treatment against cancer.

Microencapsulation of tris(dimethylaminomethyl)phenol using polystyrene shell for self-healing materials

The self-healing function of the polymer material has been realized by the microencapsulation technology of the healing agent. A novel microcapsule contained tris(dimethylaminomethyl)phenol (DMP-30) with polystyrene as shell material was prepared via solvent evaporation technique in a W/O/W emulsion. Two key strategies were implemented to prepare the microcapsules successfully. First, a small amount of deionized water was added into DMP-30 to form a complex, and a stable W/O emulsion was successfully prepared. The second one is to form a stable W/O/W emulsion system with the high viscosity aqueous solution added with Arabia gum and surfactants as the third phase. In addition, the influencing factors of microcapsules preparation were investigated systematically. The chemical structure of DMP-30 microcapsule was investigated by Fourier transform infrared. The morphology and shell thickness of the microcapsules were observed by optical microscope and scanning electron microscope. The reactivity of the core material was studied by differential scanning calorimetry. The thermal properties of microcapsules were studied by thermogravimetric analysis. The environmental resistance of microcapsules was verified by the isothermal aging test. Results showed that DMP-30 was successfully coated by polystyrene and the microcapsule size was in the range of 2–40 μm. The synthesized microcapsules were thermally stable below 50 °C.