In the past few decades, 3D printing has played a significant role in fabricating scaffolds with consistent, complex structure that meet patient-specific needs in future clinical applications. Although many studies have contributed to this emerging field of additive manufacturing, which includes material development and computer-aided scaffold design, current quantitative analyses do not correlate material properties, printing parameters, and printing outcomes to a great extent. A model that correlates these properties has tremendous potential to standardize 3D printing for tissue engineering and biomaterial science. In this study, we printed poly(lactic-co-glycolic acid) (PLGA) utilizing a direct melt extrusion technique without additional ingredients. We investigated PLGA with various lactic acid: glycolic acid (LA:GA) molecular weight ratios and end caps to demonstrate the dependence of the extrusion process on the polymer composition. Micro-computed tomography was then used to evaluate printed scaffolds containing different LA:GA ratios, composed of different fiber patterns, and processed under different printing conditions. We built a statistical model to reveal the correlation and predominant factors that determine printing precision. Our model showed a strong linear relationship between the actual and predicted precision under different combinations of printing conditions and material compositions. This quantitative examination establishes a significant foreground to 3D print biomaterials following a systematic fabrication procedure. Additionally, our proposed statistical models can be applied to couple specific biomaterials and 3D printing applications for patient implants with particular requirements.

Buyang Huanwu decoction (BYHWD) has been used for centuries to treat paralysis and stroke. Previously, we have demonstrated that BYHWD combined with mesenchymal stem cell (MSC) transplantation attenuates ischemic injury partly by upregulating angiogenesis. However, the mechanisms of this drug for stroke treatment are not completely understood. Here, we aimed to clarify the mechanism of BYHWD on angiogenesis mediated by MSCs. Firstly, we verified microvessels with a size of 50-100 nm produced by either MSCs or MSCs treated by 500 μg/ml BYHWD. These exosomes were purified and found to be able to activate vascular endothelial growth factor (VEGF) expression in endothelial cells (ECs). Moreover, exosomes from MSCs and MSCs treated by BYHWD induced elevated microRNA (miRNA)-126 expression and reduced miR-221 and miR-222 expression. In MSCs, disruption of dicer, an enzyme responsible for miRNA maturation, by dicer small interfering RNA (siRNA), or RNase pretreatment abolished this ability of the exosomes. Additionally, exosomes from MSCs treated by BYHWD promoted VEGF and Ki-67 expression and augmented vascular density in rat brain after bilateral carotid artery ligation. In conclusion, our study revealed that BYHWD exposure augmented angiogenetic miRNA and VEGF expression in exosomes secreted by MSCs and elevated angiogenesis in rat brain.

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Recently, advanced stem cell and tissue engineering approach is recognized as an emerging and fascinating strategy to promote the neural repair for spinal cord injury (SCI). Hydrogel can be properly...

These results suggest that IgG anti-GM1 antibodies are associated with AMAN, but not with AIDP, and that IgM antibodies against GM1, GM2, and GM3 are associated with facial nerve palsy. Muscle Nerve 55: 470-475, 2017.

BMSC-laden gelatin hydrogels dual-enzymatically cross-linked by GOX and HRP could significantly promote the neurological function recovery of TBI in rats.

In situ forming hydrogel shows enormous potential as a therapeutic implant or carrier in tissue repair and regeneration. It can perfectly seal or fill the defective tissue, consequently functioning as a cell/drug delivery vehicle. In this contribution, a new gelatin hydrogel with dual-enzymatic cross-linking of horseradish peroxidase (HRP) and galactose oxidase (GalOx) was developed, and the therapeutic effect of this hydrogel encapsulated with bone mesenchymal stem cells (BMSC) in dermal wound healing was investigated. This hydrogel possesses a quick gelation process within 5 min, a high water content, and a uniform three-dimensional (3D) porous network. The 3D cell culture study indicated that gelatin hydrogel matrix of HRP(5U):GalOx(1U) or HRP(2U):GalOx(1U) could provide a friendly 3D microenvironment for supporting the survival, proliferation, and spread of mouse bone mesenchymal stem cells (BMSC) with negligible cytotoxicity. Hematoxylin and eosin staining test suggested that this hydrogel has superior histocompatibility and minimized immune response in vivo. Furthermore, wound-healing studies on a C57 mouse model of excised wound demonstrated that BMSC-laden gelatin hydrogel could significantly accelerate the wound closure as compared to other groups. These data suggest that this dual-enzymatically cross-linked gelatin hydrogel loaded with BMSC has a great potential in wound healing and other tissue-regeneration applications.

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