Therapeutic potential of stem cells in skin repair and regeneration

Stem cells are defined by their capacity of self-renewal and multilineage differentiation, which make them uniquely situated to treat a broad spectrum of human diseases. Based on a series of remarkable studies in several fields of regenerative medicine, their application is not too far from the clinical practice. Full-thickness burns and severe traumas can injure skin and its appendages, which protect animals from water loss. temperature change, radiation, trauma and infection. In adults, the normal outcome of repair of massive full-thickness burns is fibrosis and scarring without any appendages, such as hair follicles, sweat and sebaceous glands. Perfect skin regeneration has been considered im-possible due to the limited regenerative capacity of epider- mal keratinocytes, which are generally thought to be the key source of the epidermis and skin appendages. Currently, researches on stem cells, such as epidermal stem cells, dermal stem cells, mesenchymal stem cells from bone marrow, and embryonic stem cells, bring promise to functional repair of skin after severe burn injury, namely, complete regeneration of skin and its appendages. In this study, we present an overview of the most recent advances in skin repair and regeneration by using stem cells.

4-Axis printing microfibrous tubular scaffold and tracheal cartilage application

Long-segment defects remain a major problem in clinical treatment of tubular tissue reconstruction.The design of tubular scaffold with desired structure and functional properties suitable for tubular tissue regeneration remains a great challenge in regenerative medicine.Here,we present a reliable method to rapidly fabricate tissueengineered tubular scaffold with hierarchical structure via 4-axis printing system.The fabrication process can be adapted to various biomaterials including hydrogels,thermoplastic materials and thermosetting materials.Using polycaprolactone(PCL)as an example,we successfully fabricated the scaffolds with tunable tubular architecture,controllable mesh structure,radial elasticity,good flexibility,and luminal patency.As a preliminary demonstration of the applications of this technology,we prepared a hybrid tubular scaffold via the combination of the 4-axis printed elastic poly(glycerol sebacate)(PGS)bio-spring and electrospun gelatin nanofibers.The scaffolds seeded with chondrocytes formed tubular mature cartilage-like tissue both via in vitro culture and subcutaneous implantation in the nude mouse,which showed great potential for tracheal cartilage reconstruction.

Single-cell atlas of domestic pig cerebral cortex and hypothalamus

The brain of the domestic pig(Sus scrofa domesticus)has drawn considerable attention due to its high similarities to that of humans.However,the cellular compositions of the pig brain(PB)remain elusive.Here we investigated the single-nucleus transcriptomic profiles of five regions of the PB(frontal lobe,parietal lobe,temporal lobe,occipital lobe,and hypothalamus)and identified 21 cell subpopulations.The cross-species comparison of mouse and pig hypothalamus revealed the shared and specific gene expression patterns at the single-cell resolution.Furthermore,we identified cell types and molecular pathways closely associated with neurological disorders,bridging the gap between gene mutations and pathogenesis.We reported,to our knowledge,the first single-cell atlas of domestic pig cerebral cortex and hypothalamus combined with a comprehensive analysis across species,providing extensive resources for future research regarding neural science,evolutionary developmental biology,and regenerative medicine.