A major challenge in cardiac tissue engineering is the host’s immune response to artificial materials. To overcome this problem, we established a scaffold-free system for assembling cell constructs using an automated Bio-3D printer. This printer has previously been used to fabricate other three-dimensional (3D) constructs, including liver, blood vessels, and cartilage. In the present study, we tested the function in vivo of scaffold-free cardiac tubular construct fabricated using this system. Cardiomyocytes derived from induced pluripotent stem cells (iCells), endothelial cells, and fibroblasts were combined to make the spheroids. Subsequently, tubular cardiac constructs were fabricated by Bio-3D printer placing the spheroids on a needle array. Notably, the spheroid fusion and beat rate in the constructs were observed while still on the needle array. After removal from the needle array, electrical stimulation was used to test responsiveness of the constructs. An increased beat rate was observed during stimulation. Importantly, the constructs returned to their initial beat rate after stimulation was stopped. In addition, histological analysis shows cellular reorganization occurring in the cardiac constructs, which may mimic that observed during organ transplantation. Taken together, our results indicate that these engineered cardiac tubular constructs, which address both the limited supply of donor tissues as well as the immune-induced transplant rejection, has potential to be used for both clinical and drug testing applications. To our knowledge, this is the first time that cardiac tubular constructs have been produced using optimized Bio-3D printing technique and subsequently tested for their use as cardiac pumps.

Before they are used in the clinical setting, the effectiveness of artificially produced human-derived tissue-engineered medical products should be verified in an immunodeficient animal model, such as severe combined immunodeficient mice. However, small animal models are not sufficient to evaluate large-sized products for human use. Thus, an immunodeficient large animal model is necessary in order to properly evaluate the clinical efficacy of human-derived tissue-engineered products, such as artificial grafts. Here we report the development of an immunodeficient pig model, the operational immunodeficient pig (OIDP), by surgically removing the thymus and spleen, and creating a controlled immunosuppressive protocol using a combination of drugs commonly used in the clinical setting. We find that this model allows the long-term accommodation of artificial human vascular grafts. The development of the OIDP is an essential step towards a comprehensive and clinically relevant evaluation of human cell regeneration strategies at the preclinical stage.

Cardiac constructs fabricated using human induced pluripotent stem cells-derived cardiomyocytes (iPSCs-CMs) are useful for evaluating the cardiotoxicity of and cardiac response to new drugs. Previously, we fabricated scaffold-free three-dimensional (3D) tubular cardiac constructs using a bio-3D printer, which can load cardiac spheroids onto a needle array. In this study, we developed a method to measure the contractile force and to evaluate the drug response in cardiac constructs. Specifically, we measured the movement of the needle tip upon contraction of the cardiac constructs on the needle array. The contractile force and beating rate of the cardiac constructs were evaluated by analysing changes in the movement of the needle tip. To evaluate the drug response, contractile properties were measured following treatment with isoproterenol, propranolol, or blebbistatin, in which the movement of the needle tip was increased following isoproterenol treatment, but was decreased following propranolol or blebbistain, treatments. To evaluate cardiotoxicity, contraction and cell viability of the cardiac constructs were measured following doxorubicin treatment. Cell viability was found to decrease with decreasing movement of the needle tip following doxorubicin treatment. Collectively, our results show that this method can aid in evaluating the contractile force of cardiac constructs.

Background: Pharmacological approaches are widely used for post-traumatic stress disorder (PTSD) despite uncertainty over efficacy. Objectives: To determine the efficacy of all pharmacological approaches, including monotherapy, augmentation and head-to-head approaches (drug versus drug, drug versus psychotherapy), in reducing PTSD symptom severity. Method: A systematic review and meta-analysis of randomised controlled trials were undertaken; 115 studies were included. Results: Selective serotonin reuptake inhibitors (SSRIs) were found to be statistically superior to placebo in reduction of PTSD symptoms but the effect size was small (standardised mean difference −0.28, 95% CI −0.39 to −0.17). For individual monotherapy agents compared to placebo in two or more studies, we found small statistically significant evidence for the antidepressants fluoxetine, paroxetine, sertraline, venlafaxine and the antipsychotic quetiapine. For pharmacological augmentation, we found small statistically significant evidence for prazosin and risperidone. Conclusions: Some medications have a small positive effect on reducing PTSD symptom severity and can be considered as potential monotherapy treatments; these include fluoxetine, paroxetine, sertraline, venlafaxine and quetiapine. Two medications, prazosin and risperidone, also have a small positive effect when used to augment pharmacological monotherapy. There was no evidence of superiority for one intervention over another in the small number of head-to-head comparison studies. Tratamiento farmacologico para el trastorno de estres postraumatico: una revision sistematica y metanalisis de monoterapia, potenciacion y abordajes comparativos Antecedentes: Los abordajes farmacológicos se usan ampliamente para el trastorno de estrés postraumático (TEPT) a pesar de su eficacia incierta. Objetivos: Determinar la eficacia de todos los abordajes farmacológicos, incluyendo monoterapia, potenciación y abordajes comparativos (droga versus droga, droga versus psicoterapia), en la reducción de la severidad de los síntomas de TEPT. Método: Se llevó a cabo una revisión sistemática y metanálisis de estudios controlados aleatorizados; se incluyeron 115 estudios. Resultados: Se encontró que los inhibidores selectivos de la recaptación de serotonina (ISRSs) fueron estadísticamente superiores a placebo en la reducción de los síntomas de TEPT, pero el tamaño de efecto fue pequeño (diferencia media estandarizada −0.28, IC 95% −0.39 a −0.17). Para agentes en monoterapia individuales comparados con placebo en dos o más estudios, encontramos para los antidepresivos fluoxetina, paroxetina, sertralina, venlafaxina y el antipsicótico quetiapina una evidencia estadísticamente significativa pequeña. Para la potenciación farmacológica, encontramos para prazosina y risperidona, evidencia estadísticamente significativa pequeña. Conclusiones: Algunos medicamentos tienen un efecto positivo pequeño en la reducción de la severidad de los síntomas de TEPT y pueden ser considerados como potenciales tratamientos en monoterap...

Excellent thermal and operational stabilities of thermophilic enzymes can greatly increase the applicability of biocatalysis in various industrial fields. However, thermophilic enzymes are generally incompatible with thermo-labile substrates, products, and cofactors, since they show the maximal activities at high temperatures. Despite their pivotal roles in a wide range of enzymatic redox reactions, NAD(P)(+) and NAD(P)H exhibit relatively low stabilities at high temperatures, tending to be a major obstacle in the long-term operation of biocatalytic chemical manufacturing with thermophilic enzymes. In this study, we constructed an in vitro artificial metabolic pathway for the salvage synthesis of NAD(+) from its degradation products by the combination of eight thermophilic enzymes. The enzymes were heterologously produced in recombinant Escherichia coli and the heat-treated crude extracts of the recombinant cells were directly used as enzyme solutions. When incubated with experimentally optimized concentrations of the enzymes at 60°C, the NAD(+) concentration could be kept almost constant for 15h.