Biophysical cues of in vitro biomaterials-based artificial extracellular matrix guide cancer cell plasticity

Clinical evidence supports a role for the extracellular matrix (ECM) in cancer plasticity across multiple tumor types. The lack of in vitro models that represent the native ECMs is a significant challenge for cancer research and drug discovery. Therefore, a major motivation for developing new tumor models is to create the artificial ECM in vitro. Engineered biomaterials can closely mimic the architectural and mechanical properties of ECM to investigate their specific effects on cancer progression, offering an alternative to animal models for the testing of cancer cell behaviors. In this review, we focused on the biomaterials from different sources applied in the fabrication of the artificial ECM and their biophysical cues to recapitulate key features of tumor niche. Furthermore, we summarized how the distinct biophysical cues guided cell behaviors of cancer plasticity, including morphology, epithelial-to-mesenchymal transition (EMT), enrichment of cancer stem cells (CSCs), proliferation, migration/invasion and drug resistance. We also discuss the future opportunities in using the artificial ECM for applications of tumorigenesis research and precision medicine, as well as provide useful messages of principles for designing suitable biomaterial scaffolds.

Self-assembling Molecular Medicine for the Subacute Phase of Ischemic Stroke

Ischemic stroke leads to acute neuron death and forms an injured core, triggering delayed cell death at the penumbra. The impaired brain functions after ischemic stroke are hardly recovered because of the limited regenerative properties. However, recent rodent intervention studies manipulating the extracellular environments at the subacute phase shed new light on the regenerative potency of the injured brain. This review introduces the rational design of artificial extracellular matrix (ECM) mimics using supramolecular peptidic scaffolds, which self-assemble via non-covalent bonds and form hydrogels. The facile customizability of the peptide structures allows tuning the hydrogels' physical and biochemical properties, such as charge states, hydrophobicity, cell adhesiveness, stiffness, and stimuli responses. Supramolecular peptidic materials can create safer and more economical drugs than polymer materials and cell transplantation. We also discuss the importance of activating developmental programs for the recovery at the subacute phase of ischemic stroke. Self-assembling molecular medicine mimicking the ECMs and activating developmental programs may stand as a new drug modality of regenerative medicine in various tissues.