Drug release and magneto-calorific analysis of magnetic lipid microcapsules for potential cancer therapeutics

Fabrication, modification and application of lipid nanotubes

The potential application of high aspect-ratio nanomaterials motivates the development of the fabrication and modification of lipid nanotubes(LNTs). To date, diverse fabricate processes and elaborate template procedures have produced suitable tubular architectures with definite dimensions and complex structures for expected functions and applications. Herein, we comprehensively summarize the fabrication of LNTs in vitro and discuss the progress made on the micro/nanomaterials fabrication using LNTs as a template, as well as the functions and possible application of a wide range of LNTs as fundamental or derivative material. In addition, the characteristics, advantages, and disadvantages of different fabrication, modification methods, and development prospects of LNTs were briefly summarized.

Acid-Directed Electrostatic Self-Assembly Generates Charge-Reversible Bacteria for Enhanced Tumor Targeting and Low Tissue Trapping

Despite recent preclinical progress with oncolytic bacteria in cancer therapy, dose-limiting toxicity has been a long-standing challenge for clinical application. Genetic and chemical modifications for enhancing the bacterial tumor-targeting ability have been unable to establish a balance between increasing its specificity and effectiveness while decreasing side effects. Herein, we report a simple, highly efficient method for rapidly self-assembling a clinically used lipid on bacterium and for reducing its minimum effective dose and toxicity to normal organs. The resultant bacteria present the ability to reverse-charge between neutral and acidic solutions, thus enabling weak interactions with the negatively charged normal cells, hence increasing their biocompatibility with blood cells and with the immune system. Additionally, the lipid-coated bacteria exhibit a longer blood circulation lifetime and low tissue trapping compared with the wild-type strains. Thereby, the engineered bacteria show enhanced tumor specificity and effectiveness even at low doses. Multiple visualization techniques are used for vividly demonstrating the time course of bacterial circulation in the blood and normal organs after intravenous administration. We believe that these methods for biointerfacial lipid self-assembly and evaluation of bacterial systemic circulation possess vast potential in exquisitely fabricating engineered bacteria for cancer therapy in the future.

Extrusion: A New Method for Rapid Formulation of High-Yield, Monodisperse Nanobubbles

Shell-stabilized gas microbubbles (MB) and nanobubbles (NB) are frequently used for biomedical ultrasound imaging and therapeutic applications. While it is widely recognized that monodisperse bubbles can be more effective in these applications, the efficient formulation of uniform bubbles at high concentrations is difficult to achieve. Here, it is demonstrated that a standard mini-extruder setup, commonly used to make vesicles or liposomes, can be used to quickly and efficiently generate monodisperse NBs with high yield. In this highly reproducible technique, the NBs obtained have an average diameter of 0.16 ± 0.05 µm and concentration of 6.2 ± 1.8 × 10¹⁰  NBs mL^-1 compared to 0.32 ± 0.1 µm and 3.2 ± 0.7 × 10¹¹  mL^-1 for NBs made using mechanical agitation. Parameters affecting the extrusion and NB generation process including the temperature, concentration of the lipid solution, and the number of passages through the extruder are also examined. Moreover, it is demonstrated that extruded NBs show a strong acoustic response in vitro and a strong and persistent US signal enhancement under nonlinear contrast enhanced ultrasound imaging in mice. The extrusion process is a new, efficient, and scalable technique that can be used to easily produce high yield smaller monodispersed nanobubbles.