Nano-structure of vitronectin/heparin on cell membrane for stimulating single cell in iPSC-derived embryoid body

Biomedical applications of engineered heparin-based materials

Heparin is a negatively charged polysaccharide with various chain lengths and a hydrophilic backbone. Due to its fascinating chemical and physical properties, nontoxicity, biocompatibility, and biodegradability, heparin has been extensively used in different fields of medicine, such as cardiovascular and hematology. This review highlights recent and future advancements in designing materials based on heparin for various biomedical applications. The physicochemical and mechanical properties, biocompatibility, toxicity, and biodegradability of heparin are discussed. In addition, the applications of heparin-based materials in various biomedical fields, such as drug/gene delivery, tissue engineering, cancer therapy, and biosensors, are reviewed. Finally, challenges, opportunities, and future perspectives in preparing heparin-based materials are summarized.

Coating Bioactive Microcapsules with Tannic Acid Enhances the Phenotype of the Encapsulated Pluripotent Stem Cells

Human pluripotent stem cells (hPSCs) may be differentiated into any adult cell type and therefore hold incredible promise for cell therapeutics and disease modeling. There is increasing interest in three-dimensional (3D) hPSC culture because of improved differentiation outcomes and potential for scale up. Our team has recently described bioactive heparin (Hep)-containing core-shell microcapsules that promote rapid aggregation of stem cells into spheroids and may also be loaded with growth factors for the local and sustained delivery to the encapsulated cells. In this study, we explored the possibility of further modulating bioactivity of microcapsules through the use of an ultrathin coating composed of tannic acid (TA). Deposition of the TA film onto model substrates functionalized with Hep and poly(ethylene glycol) was characterized by ellipsometry and atomic force microscopy. Furthermore, the presence of the TA coating was observed to increase the amount of basic fibroblast growth factor (bFGF) incorporation by up to twofold and to extend its release from 5 to 7 days. Most significantly, TA-microcapsules loaded with bFGF induced higher levels of pluripotency expression compared to uncoated microcapsules containing bFGF. Engineered microcapsules described here represent a new stem cell culture approach that enables 3D cultivation and relies on local delivery of inductive cues.