All-aqueous microfluidic printing of multifunctional bioactive microfibers promote whole-stage wound healing.

Wound healing involves multi-stages of physiological responses, including hemostasis, inflammation, cell proliferation, and tissue remodeling. Satisfying all demands throughout different stages remains a rarely addressed challenge. Here we introduce an innovative all-aqueous microfluidic printing technique for fabricating multifunctional bioactive microfibers, effectively contributing to all four phases of the healing process. The distinctive feature of the developed microfibers lies in their capacity to be printed in a free-form manner in the aqueous-two phase system (ATPS). This is achieved through interfacial coacervation between alkyl-chitosan and alginate, with enhanced structural integrity facilitated by simultaneous crosslinking with calcium ions and alginate. The all-aqueous printed microfibers exhibit exceptional performance in terms of cell recruitment, blood cell coagulation, and hemostasis. The inclusion of a dodecyl carbon chain and amino groups in alkyl-chitosan imparts remarkable antimicrobial properties by anchoring to bacteria, complemented by potent antibacterial effects of encapsulated silver nanoparticles. Moreover, microfibers can load bioactive drugs like epidermal growth factor (EGF), preserving their activity and enhancing therapeutic effects during cell proliferation and tissue remodeling. With these sequential functions to guide the whole-stage wound healing, this work offers a versatile and robust paradigm for comprehensive wound treatment, holding great potential for optimal healing outcomes.

Echocardiographic multiparameter assessment for patients with heart failure with preserved ejection fraction and atrial fibrillation.

We aimed to assess the echocardiographic parameters of cardiac structure and function in patients with heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF). Thirty-seven HFpEF patients with AF were selected, while 38 patients with simple HFpEF in the same period were selected as controls. Three-dimensional speckle-tracking echocardiography was performed on both groups and the parameters were compared. The early diastolic longitudinal peak strain rates [early diastolic longitudinal strain rate (LSRE), early diastolic circumferential strain rate (CSRE), early diastolic radial strain rate (RSRE) and early diastolic rotational strain rate (RotRE)], late diastolic longitudinal peak strain rates (LSRA, CSRA, RSRA and RotRA) and untwisting parameters [untwisting rate during isovolumic relaxation time (UTRIVR) and early peak untwisting rate (UTRE)] were all negatively correlated with the ratio of early diastolic transmitral velocity to early diastolic mitral annular velocity ( E/E') (p < 0.01). The cardiac event-free survival rate of the simple HFpEF group (92.11%) was significantly higher than that of the HFpEF + AF group (81.08%) (p < 0.0001). UTRIVR had a more significant correlation with E/E' ratio than the other indicators and could serve as a sensitive indicator for evaluating the diastolic function of patients with HFpEF + AF.

Microfluidic generation of multifunctional core-shell microfibers promote wound healing.

Wound healing is a complex physiological process involving four coordinated stages, including hemostasis, anti-inflammatory, repair, and epithelial formation. Herein, multifunctional core-shell alkylated chitosan/calcium alginate microfibers are fabricated as a novel strategy for promoting wound healing by contributing to each four stages in the entire healing process. Taking advantages of the microfluidic technology, the core-shell microfibers can be generated in a continuous and convenient manner through the interfacial assembly between alkylated chitosan and Na-alginate, as well as the simultaneous crosslink between calcium and the alginate. Generated microfibers possess unique internal structure which can effectively promote the absorption of blood and exudate produced during trauma. Moreover, the dodecyl carbon chain and abundant amino groups of alkylated chitosan provide microfibers with excellent hemostatic and antibacterial properties, which can repair acute hemorrhage and destroy bacteria rapidly. Further, the chronic wound healing process of a skin injury model can be significantly promoted by applying the fabricated microfibers. With these sequential functions to guide the whole-stage wound healing, the presented multifunctional core-shell microfibers create a versatile and robust paradigm for comprehensive wound treatment.

Microfluidics in cardiovascular disease research: state of the art and future outlook.

Due to extremely severe morbidity and mortality worldwide, it is worth achieving a more in-depth and comprehensive understanding of cardiovascular diseases. Tremendous effort has been made to replicate the cardiovascular system and investigate the pathogenesis, diagnosis and treatment of cardiovascular diseases. Microfluidics can be used as a versatile primary strategy to achieve a holistic picture of cardiovascular disease. Here, a brief review of the application of microfluidics in comprehensive cardiovascular disease research is presented, with specific discussions of the characteristics of microfluidics for investigating cardiovascular diseases integrally, including the study of pathogenetic mechanisms, the development of accurate diagnostic methods and the establishment of therapeutic treatments. Investigations of critical pathogenetic mechanisms for typical cardiovascular diseases by microfluidic-based organ-on-a-chip are categorized and reviewed, followed by a detailed summary of microfluidic-based accurate diagnostic methods. Microfluidic-assisted cardiovascular drug evaluation and screening as well as the fabrication of novel delivery vehicles are also reviewed. Finally, the challenges with and outlook on further advancing the use of microfluidics technology in cardiovascular disease research are highlighted and discussed.

Porous nano-hydroxyapatite/poly(vinyl alcohol) composite hydrogel as artificial cornea fringe: characterization and evaluation in vitro.

A nano-hydroxyapatite/poly(vinyl alcohol) (n-HA/PVA) composite hydrogel was employed as artificial cornea fringe to improve biocompatibility for the firm fixation between material and surrounding host tissues. The morphology and swelling behavior, as well as mechanical strength of the fringes were characterized. The results showed that the n-HA/PVA fringes had interconnective porous structure, high water content and good mechanical properties. With the aid of cell culture observed by inverted microscopy, scanning electron microscopy (SEM) and MTT test, it was concluded that PVA hydrogel modified with n-HA can improve biocompatibility and has no negative effects on the corneal fibroblasts in vitro. These findings indicate that the porous n-HA/PVA fringe can allow invasion and proliferation of cells, and can function as a fringe for artificial cornea.

In vitro and in vivo study to the biocompatibility and biodegradation of hydroxyapatite/poly(vinyl alcohol)/gelatin composite.

A novel porous composite material composed of hydroxyapatite, poly(vinyl alcohol) (PVA), and gelatin (Gel) was fabricated by emulsification. Scanning electron microscopy showed that the material had a well-interconnected porous structure including many macropores (100-500 microm) and micropores (less than 20 microm) on their walls. The composite had a porosity of 78% and showed high water absorption up to 312.7% indicating a good water-swellable behavior that is a characteristic of hydrogel materials. When immersed in water, the scaffold's weight continuously decreased. After immersion in simulated body fluid, the weight continuously increased because Ca(2+) and PO(3-) (4) ions deposited on the surface and the internal surfaces of the material pores. The deposit was proved to be carbonated hydroxyapatite by thin-film X-ray diffraction, Fourier transform infrared spectroscopy and energy dispersive X-ray analysis. The composite was detected to be non-cytotoxicity by MTT assay. The HA/PVA/Gel material was also implanted subcutaneously in the dorsal region of adult female rats. After 12 weeks of implantation, the porous material adhered tightly with the surrounding tissue, and the ingrowth of fibrous tissue as well as the material's partial degradation was observed, which partly indicated that the composite was biocompatible in vivo. In conclusion, the porous HA/PVA/Gel composite is a promising scaffold for cartilage tissue engineering with more studies.