Shuang Yang,Linhao Lan,Mingda Gong,Ke Yang,Xiaoming Li
An effective dressing is essential for wound healing. In fact, the wettability performance is one of the most important factors of a wound dressing. The fundamental functions of a wound dressing involve the absorption of excess exudates and maintenance of optimal moisture at the wound by controlling water evaporation. Here, we designed a type of chitosan (CS) sponge and PCL nanofibrous membrane composite dressing with asymmetric wettability surfaces as wound healing materials for biomedical applications. The hydrophobic surfaces of the composite dressing were waterproof and could efficiently control the water vapor transmission rate, whereas the hydrophilic surface of the CS sponge had good cytocompatibility and water-absorbing capability. Insulin-like growth factor-2 (IGF-2) was added to the CS sponge, and exhibited a stimulatory effect on fibroblasts migration and proliferation. Therefore, the fabricated CS sponge and PCL membrane composite dressing had excellent cytocompatibility, vapor transmission rate, and liquid absorption and asymmetric wettability, suggesting its potential as a promising alternative to traditional wound dressing.
Jie Chen,Xicheng Wang,Hua Ye,Zhenyan Yu,Longbao Feng,Jing Zhou,Yajin Che
As one of the most commonly used materials in liver tissue engineering, hydrogel has received much attention in recent years. In this work, we prepared a gelatin methacrylate (GelMA)/oxidized hyaluronic acid (OHA)/galactosylated chitosan (Gal-CS)/Fe (III)@ [email protected] 200 (TA200) hydrogel loaded with insulin-like growth factor 2 (IGF-2) for regeneration of damaged hepatocytes. Fe (III)@TA microspheres served as carrier to achieve sustained release of IGF-2 to promote hepatocytes regeneration. Galactose ligands could bind to the asialoglycoprotein receptor (ASGPR) on the surface of hepatocytes. Galactosylated chitosan could significantly increase the specific function of hepatocytes. The hydrogel we prepared had a storage modulus of 1100 Pa and was suitable for migration of hepatocytes. The release ratio of IGF-2 could reach up to 90% within 14 days. For carbon tetrachloride (CCl 4 ) induced human hepatic stellate cell line LX2 damage, GelMA/OHA/Gal-CS/TA200 hydrogel could significantly improve the survival of LX2 cells. The expression of HNF-4α and transferrin was detected in LX2 cells treated with hydrogel, indicating that the specific function of the liver was also restored. In summary, the GelMA/OHA/Gal-CS/TA200 hydrogels could be used as new tissue engineering scaffolds for the construction of artificial livers.
Mesenchymal stem cells (MSCs) transplantation has emerged as a potential therapeutic approach for Alzheimer's disease (AD). However, the poor proliferation capacity and low survival rate of engrafted MSCs in the hostile microenvironment of AD limit their therapeutic efficiency. Lin28B is a conserved RNA-binding protein associated with cell self-renewal and survival. The purpose of the present study was to explore whether lin28B might influence the functions of implanted MSCs and strengthen their neuroprotective potential in AD. A gain-of-function assay was used to upregulate lin28B expression in MSCs by lentiviral transfection. Our in vitro results indicated that lin28B promoted MSCs proliferation and migration, and protected MSCs against Aβ1–42-induced cell death by upregulating insulin-like growth factor-2 (IGF-2). Blockage of IGF-2 partially abrogated the above effects of lin28B. After intracerebroventricular injection into amyloid precursor protein/presenilin 1 mice, implanted MSCs were monitored using bioluminescence imaging. We observed that administration of MSCs transfected with lin28B significantly stimulated their proliferation and prolonged cell retention after delivery. Moreover, administration of the transfected MSCs markedly mitigated cognitive deficits, promoted amyloid plaque clearance, decreased the activation of microglia, and reduced neuronal cell death. The data above confirmed our hypothesis that lin28B is a crucial modulator determining the fate of transplanted MSCs by regulating IGF-2-associated pathways and thereby enhancing their protective effects against AD.
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