Building Osteogenic Microenvironments with a Double-Network Composite Hydrogel for Bone Repair

The critical factor determining the in vivo effect of bone repair materials is the microenvironment,which greatly depends on their abilities to promote vascularization and bone formation.However,implant materials are far from ideal candidates for guiding bone regeneration due to their deficient angiogenic and osteogenic microenvironments.Herein,a double-network composite hydrogel combining vascular endothelial growth factor(VEGF)-mimetic peptide with hydroxyapatite(HA)precursor was developed to build an osteogenic microenvironment for bone repair.The hydrogel was prepared by mixing acrylatedβ-cyclodextrins and octacalcium phosphate(OCP),an HA precursor,with gelatin solution,followed by ultraviolet photo-crosslinking.To improve the angiogenic potential of the hydrogel,QK,a VEGF-mimicking peptide,was loaded in acrylatedβ-cyclodextrins.The QK-loaded hydrogel promoted tube formation of human umbilical vein endothelial cells and upregulated the expression of angiogenesis-related genes,such as Flt1,Kdr,and VEGF,in bone marrow mesenchymal stem cells.Moreover,QK could recruit bone marrow mesenchymal stem cells.Furthermore,OCP in the composite hydrogel could be transformed into HA and release calcium ions facilitating bone regeneration.The double-network composite hydrogel integrated QK and OCP showed obvious osteoinductive activity.The results of animal experiments showed that the composite hydrogel enhanced bone regeneration in skull defects of rats,due to perfect synergistic effects of QK and OCP on vascularized bone regeneration.In summary,improving the angiogenic and osteogenic microenvironments by our double-network composite hydrogel shows promising prospects for bone repair.

A strategy for generating rice apomixis by gene editing

Apomixis is an asexual reproduction way of plants that can produce clonal offspring through seeds.In this study,we introduced apomixis into rice(Oryza sativa)by mutating OsSPO11-1,OsREC8,OsOSD1,and OsMATL through a CRISPR/Cas9 system.The quadruple mutant showed a transformation from meiosis to mitosis and produced clonal diploid gametes.With mutated Osmatl,which gives rise to haploid induction in plants,the quadruple mutant is expected to be able to be produced apomictic diploid offspring.We named this quadruple mutant as AOP(Apomictic Offspring Producer)for its ability to produce apomictic offspring.

Global production aspirations and internationalization by state-owned enterprises:A Co-evolutionary view of statedriven industrialized economy

The study aims to explore whether internationalization by state-owned enterprises is a curse or blessing in the context of aspirant industrial economies,such as China.What do state-owned enterprises'global production aspirations,such as outward foreign direct investment,bring into their home country?To answer this question,this study proposes a unique,co-evolutionary perspective of the state-driven industrialized economy by leveraging insights from economic discoveries such as Adam Smith's wealth of nations,David Ricardo's comparative advantage,and Michael Porter's competitive advantage.This view suggests that an outward foreign investment strategy may likely provide state-owned enterprises with access to resources and advanced production technologies,enhance innovation capabilities,gain more competitive advantage,and achieve superior performance,thus leading to spillover effects on their home country's wealth,comparative advantage,and competitiveness.This study discusses China's grand policies,economic performance,and successful cross-border industrial acquisitions.