The Cell-Isolation Capsules with Rod-Like Channels Ensure the Survival and Response of Cancer Cells to Their Microenvironment.

Current macrocapsules with semipermeable but immunoprotective polymeric membranes are attractive devices to achieve the purpose of immunoisolation, however, their ability to allow diffusion of essential nutrients and oxygen is limited, which leads to a low survival rate of encapsulated cells. Here, a novel method is reported by taking advantage of thermotropic liquid crystals, sodium laurylsulfonate (SDS) liquid crystals (LCs), and rod-like crystal fragments (LCFs) to develop engineered alginate hydrogels with rod-like channels. This cell-isolation capsule with an engineered alginate hydrogel-wall allows small molecules, large molecules, and bacteria to diffuse out from the capsules freely but immobilizes the encapsulated cells inside and prevents cells in the microenvironment from moving in. The encapsulated cells show a high survival rate with isolation of host immune cells and long-term growth with adequate nutrients and oxygen supply. In addition, by sharing and responding to the normal molecular and vesicular microenvironment (NMV microenvironment), encapsulated cancer cells display a transition from tumorous phenotypes to ductal features of normal epithelial cells. Thus, this device will be potentially useful for clinical application in cell therapy by secreting molecules and for establishment of patient-derived xenograft (PDX) models that are often difficult to achieve for certain types of tumors, such as prostate cancer.

Bioinspired Shear-Flow-Driven Layer-by-Layer in Situ Self-Assembly.

Layer-by-layer (LbL) assembly is widely applied as a coating technique for the nanoscale control of architecture and related properties. However, its translational applications are limited by the time-consuming and laborious nature of the process. Inspired by the blood-clotting process, herein, we develop a shear-flow-driven LbL (SF-LbL) self-assembly approach that accelerates the adsorption rate of macromolecules by mechanically configuring the polymer chain via a coil-stretch transition, which effectively simplifies and speeds the diffusion-controlled assembly process. The structural characteristics and surface homogeneity of the SF-LbL films are improved, and diverse three-dimensional structures can be achieved. Functional SF-LbL-assembled surfaces for corneal modification are successfully fabricated, and the surface of wounded rat corneas and skin can be directly decorated in situ with SF-LbL nanofilms due to the advantages of this approach. Furthermore, in situ SF-LbL self-assembly has promise as a simple approach for the wound dressing for interventional therapeutics in the clinic, as illustrated by the successful in situ fabrication of drug-free layers consisting of chitosan and heparin on the dorsal skin of diabetic mice to rescue defective wound healing. This bioinspired self-assembly approach is expected to provide a robust and versatile platform with which to explore the surface engineering of nanofilms in science, engineering, and medicine.