Improved hemostatic effects by Fe^(3+)modified biomimetic PLLA cotton-like mat via sodium alginate grafted with dopamine

The development of an excellent,bioabsorbable hemostatic material for deep wound remains a challenge.In this work,a biodegradable cotton-like biomimetic fibrous mat of poly(L-lactic acid)(PLLA)was made by melt spinning.Subsequently,SD composite was prepared by cross-linking sodium alginate(SA)with dopamine(DA).It was immobilized on the fibre surface,which inspired by mussel byssus.Finally,Fe^(3+)was loaded onto the 0.5SD/PLLA composite by chelation with the carboxyl of alginate and phenolic hydroxy of dopamine.The haemostasis experiment found that the hemostatic time 47 s in vitro.However,the bleeding volume was 0.097 g and hemostatic time was 23 s when 20Fe^(3+)-0.5SD/PLLA was applied in the haemostasis of the rat liver.As a result of its robust hydrophilicity and bouffant cotton-like structure,it could absorb a large water from blood,which could concentrate the component of blood and reduce the clotting time.Furthermore,the addition of Fe^(3+)in the 0.5SD/PLLA had a significant effect on improve hemostatic property.It also displayed excellent antibacterial property for Escherichia coli and Staphylococcus aureus.Notably,it possesses superior hemocompatibility,cytocompatibility and histocompatibility.Hence,20Fe^(3+)-0.5SD/PLLA has high potential application in haemostasis for clinical settings due to its outstanding properties.

Gaseous sulfur trioxide induced controllable sulfonation promoting biomineralization and osseointegration of polyetheretherketone implants

Fabricating a desired porous structure on the surface of biomedical polyetheretherketone(PEEK)implants for enhancing biological functions is crucial and difficult due to its inherent chemical inertness.In this study,a porous surface of PEEK implants was fabricated by controllable sulfonation using gaseous sulfur trioxide(SO3)for different time(5,15,30,60 and 90 min).Micro-topological structure was generated on the surface of sulfonated PEEK implants preserving original mechanical properties.The protein absorption capacity and apatite forming ability was thus improved by the morphological and elemental change with higher degree of sulfonation.In combination of the appropriate micromorphology and bioactive sulfonate components,the cell adhesion,migration,proliferation and extracellular matrix secretion were obviously enhanced by the SPEEK-15 samples which were sulfonated for 15 min.Finding from this study revealed that controllable sulfonation by gaseous SO3 would be an extraordinarily strategy for improving osseointegration of PEEK implants by adjusting the microstructure and chemical composition while maintaining excellent mechanical properties.

Biomimetic polyetheretherketone microcarriers with specific surface topography and self-secreted extracellular matrix for large-scale cell expansion

Reusable microcarriers with appropriate surface topography,mechanical properties,as well as biological modification through decellularization facilitating repeated cell culture are crucial for tissue engineering applications.Herein,we report the preparation of topological polyetheretherketone(PEEK)microcarriers via gas-driven and solvent exchange method followed by hydrothermal treatment at high temperature and pressure.After hydrothermal treated for 8 h,the resulting topological PEEK microcarriers exhibit walnut-like surface topography and good sphericity as well as uniform size distribution of 350.24619.44 mm.And the average width between ravine-patterned surface of PEEK microcarriers is 7806290 nm.After repeated steam sterilization by autoclaving for three times,topological PEEK microcarriers show nearly identical results compared with previous ones indicating strong tolerance to high temperature and pressure.This is a unique advantage for large-scale cell expansion and clinical applications.Moreover,PEEK microcarriers with special topography possess higher protein adsorption efficiency.In addition,the reutilization and biofunctionalization with repeated decellularization of topological PEEK microcarriers show highly beneficial for cell adhesion and proliferation.Therefore,our study is of great importance for new generation microcarriers with micro-and nano-scale surface feature for a broad application prospect in tissue engineering.

Porous polyetheretherketone microcarriers fabricated via hydroxylation together with cellderived mineralized extracellular matrix coatings promote cell expansion and bone regeneration

Porous microcarriers have aroused increasing attention recently by facilitating oxygen and nutrient transfer,supporting cell attachment and growth with sufficient cell seeding density.In this study,porous polyetheretherketone(PEEK)microcarriers coated with mineralized extracellular matrix(mECM),known for their chemical,mechanical and biological superiority,were developed for orthopedic applications.Porous PEEK microcarriers were derived from smooth microcarriers using a simple wet-chemistry strategy involving the reduction of carbonyl groups.This treatment simultaneously modified surface topology and chemical composition.Furthermore,the microstructure,protein absorption,cytotoxicity and bioactivity of the obtained porous microcarriers were investigated.The deposition of mECM through repeated recellularization and decellularization on the surface of porous MCs further promoted cell proliferation and osteogenic activity.Additionally,the mECM coated porous microcarriers exhibited excellent bone regeneration in a rat calvarial defect repair model in vivo,suggesting huge potential applications in bone tissue engineering.