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It is widely acknowledged that an imbalanced biomechanical environment can have significant effects on myocardial pathology, leading to adverse remodelling of cardiac function if it persists. Accurate stress prediction essentially depends on the strain energy function which should have competent descriptive and predictive capabilities. Previous studies have focused on myofibre dispersion, but not on fibres along other directions. In this study, we will investigate how fibre dispersion affects myocardial biomechanical behaviours by taking into account both the myofibre dispersion and the sheet fibre dispersion, with a focus on the sheet fibre dispersion. Fibre dispersion is incorporated into a widely-used myocardial strain energy function using the discrete fibre bundle approach. We first study how different dispersion affects the descriptive capability of the strain energy function when fitting to ex vivo experimental data, and then the predictive capability in a human left ventricle during diastole. Our results show that the chosen strain energy function can achieve the best goodness-of-fit to the experimental data by including both fibre dispersion. Furthermore, noticeable differences in stress can be found in the LV model. Our results may suggest that it is necessary to include both dispersion for myofibres and the sheet fibres for the improved descriptive capability to the ex vivo experimental data and potentially more accurate stress prediction in cardiac mechanics.

Herein we report a facile approach for chitosan-heparin hydrogels with controlled release manner and their applications for intrauterine adhesion. The sol precursor was converted to gel at physiological temperature in 15 min. FTIR, SEM and swelling test were performed to characterize their compositions, morphologies and stability. In vitro releasing profiles was investigated in PBS solutions. Intrauterine injured rat model was established and treated with different methods. The results of H&E staining, Masson trichrome staining, western blots assay, immunohistochemical staining and immunofluorescence staining revealed that endogenous c-kit positive stem cells (HSCs) were recruited to the injury site and promoted the wound recovery. After 7 days' treatment, uterus treated with SDF-1α releasing hydrogel showed no difference with control group on endometrial thickness, glands number and fibrosis level. This work provides a possible method for intrauterine adhesion healing.

This work accompanies the first part of our study "effects of dispersed fibres in myocardial mechanics: Part I passive response" with a focus on myocardial active contraction. Existing studies have suggested that myofibre architecture plays an important role in myocardial active contraction. Following the first part of our study, we firstly study how the general fibre architecture affects ventricular pump function by varying the mean myofibre rotation angles, and then the impact of fibre dispersion along the myofibre direction on myocardial contraction in a left ventricle model. Dispersed active stress is described by a generalised structure tensor method for its computational efficiency. Our results show that both the myofibre rotation angle and its dispersion can significantly affect cardiac pump function by redistributing active tension circumferentially and longitudinally. For example, larger myofibre rotation angle and higher active tension along the sheet-normal direction can lead to much reduced end-systolic volume and higher longitudinal shortening, and thus a larger ejection fraction. In summary, these two studies together have demonstrated that it is necessary and essential to include realistic fibre structures (both fibre rotation angle and fibre dispersion) in personalised cardiac modelling for accurate myocardial dynamics prediction.

In this paper, well-defined CHMSs were synthesized through co-hydrolysis of tetraethylsiloxane (TEOS) and 3-aminopropyltriethoxysilane (APTS) template by mesomorphous complexes of hexadecylpyridinium chloride (CPC) and poly(acrylic acid) (PAA). It was demonstrated that the adding amount of APTS in the reaction system played a key role in the formation of the hollow cage-like structure and a possible formation mechanism of CHMSs was proposed. The synthesized CHMSs presented as uniform microsphers with average diameter of 600 nm and possessed tri-model pore structure that were the ordered mesopores (˜3 nm) originated from CPC micelle, the secondary nanopores (˜55 nm) templated by phase separated PAA chain in the silica shell as well as the hollow cavity (several hundred nanometer). At the same time, the co-hydrolysis of APTS resulted in amino groups functionalized silica framework of the CHMSs. Ascribed to the unique structure and the inherent amino groups, the CHMSs were utilized as scaffold for preparation of heterogeneous noble metal nanoparticle catalysts. By choosing the palladium (Pd) as a typical example, 1-Pd@CHSMs catalysts containing 1.0 wt% Pd and uniform distributed small size Pd nanoparticles (˜2.9 nm) were obtained. The catalytic reduction of 4-nitrophenol demonstrated that the heterogeneous 1-Pd@CHSMs catalyst was efficient and reusable.