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Tissue engineering (TE) scaffolds with appropriate Poisson's ratio (PR) are suitable for mimicking the environment of native tissues on which cells could survive and thrive better. Herein, cellular structured scaffolds are made by a new composite poly(ethylene glycol) diacrylate/cellulose nanofibril aerogel, with prototypes of the hexagonal, reentrant, and semireentrant models. Scaffolds with different geometry parameters (l, t, α) are designed and simulated by COMSOL to enable precise regulation of their PR. Then, nine groups of scaffolds with different PRs ranging from -0.5 to 0.85 are designed by adjusting geometry parameters and fabricated by using stereolithography and freeze-drying techniques. Subsequently, bone marrow mesenchymal stem cells (BMSc) are cultured on these scaffolds for 21 days, during which CCK8 assay, fluorescence microscope observation, and real-time polymerase chain reaction experiments are performed to characterize the proliferation and differentiation of BMSc. The results reflect that the scaffolds with different PR can provide various stress environments for cells, and the scaffold with zero PR is the most suitable for BMSc differentiating into chondrocytes during early culture experiments. This study suggests that tuning PR precisely is an attractive and effective strategy to provide a cells-suitable environment for scaffold fabrication for TE., (© 2022 Wiley Periodicals LLC.)

Loss of ovarian function (e.g., due to menopause) leads to profound physiological effects in women including changes in sexual function and osteoporosis. Hormone therapies are a known solution, but their use has significantly decreased due to concerns over cardiovascular disease and certain cancers. We recently reported a tissue-engineering strategy for cell hormone therapy (cHT) in which granulosa cells and theca cells are encapsulated to mimic native ovarian follicles. cHT improved physiological outcomes and safety compared to pharmacological hormone therapies in a rat ovariectomy model. However, cHT did not achieve estrogen levels as high as ovary-intact animals. In this report, we examined if hormone secretion from cHT constructs is impacted by incorporation of bone marrow-derived mesenchymal stem cells (BMSC) since these cells contain regulatory factors such as aromatase necessary for estrogen production. Incorporation of BMSCs led to enhanced estrogen secretion in vitro. Moreover, cHT constructs with BMSCs achieved estrogen secretion levels significantly greater than constructs without BMSCs in ovariectomized rats from 70 to 90 days after implantation, while also regulating pituitary hormones. cHT constructs with BMSC ameliorated estrogen deficiency-induced uterine atrophy without hyperplasia. The results indicate that inclusion of BMSC in cHT strategies can improve performance.

Impact Statement: Due to high-fat and high-sugar diets accompanied by sedentary lifestyles, diabetes has become a global epidemic. Literature findings suggest a potential therapeutic effect of Nrg4 on treating obesity-related metabolic disorders including type 2 diabetes (T2D). Adipose tissue-derived MSCs (ADSCs) were used in our study as they are abundant and can be harvested with minimally invasive procedures. In the end, our study reveals that ADSC transplantation improves glucose tolerance and metabolic balance in HFD-fed mice by multiple mechanisms, including upregulating GLUT4 expression and suppressing inflammation. More importantly, our study shows that Nrg4 overexpression could improve the efficacy of ADSCs in ameliorating insulin resistance (IR) and other obesity-related metabolic disorders, given the function of Nrg4 in attenuating hepatic lipogenesis. It would provide a new therapeutic strategy for the treatment of obesity, IR, and T2D.

An in situ forming spruce xylan-based hydrogel was synthesized in two steps with the intended use of cell encapsulation and in vivo delivery. First, bioconjugate was obtained through the reaction of glucuronic acid groups from xylan backbone with tyramine (TA). After that, the gelation process was enabled by enzymatic crosslinking of the phenol-containing TA-xylan conjugate. Exhibiting an exponential increase in the storage modulus, a 3D gel network was formed in about 20s. The designed gel showed extensive swelling and retained its mechanical integrity for more than two months. Mesenchymal stem cells were encapsulated in the hydrogel and cultured for one week. The cells retained their adipogenic differentiation capacity inside the gel, as verified by lipid accumulation. From these facts, we conclude that spruce xylan is a promising precursor for in situ forming hydrogels and should be evaluated further for tissue engineering purposes., (Copyright © 2013 Elsevier Ltd. All rights reserved.)