Decellularized extracellular matrices have been clinically used for tendon regeneration. However, only a few systematic studies have compared tendon stem/progenitor cells to mesenchymal stromal cells on the tendon-derived decellularized matrix. In the present study, we prepared extracellular matrix derived from porcine tendons and seeded with tendon stem/progenitor cells, embryonic stem cell-derived mesenchymal stromal cells or without stem cells. Then we implanted the mixture (composed of stem cells and scaffold) into the defect of a rat Achilles tendon. Next, 4 weeks post-surgery the regenerated tendon tissue was collected. Histological staining, immunohistochemistry, determination of collagen content, transmission electron microscopy, and biomechanical testing were performed to evaluate the tendon structure and biomechanical properties. Our study collectively demonstrated that decellularized extracellular matrix derived from porcine tendons significantly promoted the regeneration of injured tendons when combined with tendon stem/progenitor cells or embryonic stem cell-mesenchymal stromal cells. Compared to embryonic stem cell-mesenchymal stromal cells, tendon stem/progenitor cells combined with decellularized matrix showed more improvement in the structural and biomechanical properties of regenerated tendons in vivo. These findings suggest a promising strategy for functional tendon tissue regeneration and further studies are warranted to develop a functional tendon tissue regeneration utilizing tendon stem/progenitor cells integrated with a tendon-derived decellularized matrix.

Late thrombosis and restenosis remain major challenges to the safety of drug-eluting stents. Biofunctional modification to endow the surface with selective anticoagulation and promote endothelium regeneration has become a hotpot recently. In this study, chitosan and heparin were found to form three-dimensional nanoparticles by spontaneous electrostatic interaction. Based on the specific binding properties between heparin and nerve growth factor (NGF), a new type of NGF-loaded heparin/chitosan nanoparticles was constructed for surface modification. The results of material characterization show that the nanoparticles are successfully immobilized on the surface of the material. In vitro blood compatibility and endothelial cell compatibility assay showed that the modified surface could selectively inhibit platelet adhesion and smooth muscle cell overproliferation, while accelerating endothelialization via promoting endothelial cell proliferation and enhancing endothelial progenitor cell mobilization.

Bone is a hierarchical architecture that consists of both inorganic and organic components. The organic components, including collagen and numerous non-collagenous biomolecules, are crucial for maintaining the mechanical strength and physiological functions of bone. The native structures of organic components and especially the mutual interactions between different components are important questions to be addressed. Among different analytical techniques, solid-state nuclear magnetic resonance (SSNMR) spectroscopy is a powerful tool to reveal the chemical and interactional information at an atomic level. Recent advancements of SSNMR technology and experimental protocols have brought great advances in understanding the molecular details in native bones. In this review, we summarize the progresses on the SSNMR studies of various organic components in the bone matrix. In the first part, we review the studies on collagen from four different aspects: (1) water-associated molecular dynamics; (2) the intrahelical/interhelical interactions in collagen residues; (3) the interactions between collagen and citrate; and (4) the cross-linking between collagen and inorganic surface. In the second part, we review the studies on the non-protein biomolecules including sugar species, citrate, lipids, and nucleic acids. In the end, we propose an outlook of future directions for SSNMR investigations on bones.

Background: Ankle-foot orthoses (AFO) can improve gait posture and walking ability in post-stroke patients. However, the effect of AFO on gait parameters in post-stroke patients according to the Brunnstrom stage of stroke recovery of the lower limbs remains unclear. The study aimed to investigate whether stroke patients with different Brunnstrom stages benefit from wearing AFO. Methods: Twenty-five post-stroke participants included 18 men (50 ± 13 years) and 7 women (60 ± 15 years). The patients were divided based on Brunnstrom stage III or IV of the lower limbs. All patients underwent the gait and timed up and go (TUG) test using a gait analysis system while walking barefoot or with an AFO. The spatiotemporal and asymmetric parameters were analyzed. Results: All 25 patients completed the study. Significant differences were observed between barefoot and AFO use in TUG time (P < 0.001) but not walking velocity (P > 0.05). The main effect of the swing time ratio was significant in both groups (P < 0.05); however, the main effects of stride length, stance time, and gait asymmetry ratio were nonsignificant (P > 0.05). For barefoot versus AFO, the main effects of stride length (P < 0.05) and swing time (P < 0.01) ratios were significant, whereas those of stance time and gait asymmetry ratio were nonsignificant (P > 0.05). Conclusions: Post-stroke patients with lower Brunnstrom stages benefitted more from AFO, particularly in gait asymmetry.

Functional constipation (FC) is a common functional gastrointestinal disorder thought to arise from the brain–gut axis dysfunction, yet direct human neurophysiological evidence is lacking. We recorded high-density electroencephalography (EEG) data in 21 FC patients and 37 healthy controls across resting, cognitive, and defecation-related tasks. We observed that FC patients displayed a consistent, task-dependent signature compared with healthy controls. At the regional level, FC patients exhibited increased alpha during both resting and defecation-related tasks, reduced temporal gamma during defecation-related tasks, as well as elevated temporal theta during the cognitive task. At the global level, we found altered network properties, such as global efficiency in the delta and beta band networks during resting and defecation-related tasks. These findings establish a direct neurophysiological link between specific, condition-dependent perturbations in cortical rhythm activity and FC pathophysiology. Our work implicates the brain–gut axis in symptom generation and opens a path toward EEG-based biomarkers and targeted neuromodulatory therapies.