Combination of stem cell therapy and acupuncture to treat ischemic stroke: a prospective review.

Stroke is the second leading cause globally that leads to severe disability and death. Stem cell therapy has been developed over the recent years to treat stroke and diminish the mortality and disability rate of brain injuries. Acupuncture, which can activate endogenous recovery via physical stimuli, has been applied to enhance the recovery and rehabilitation of stroke patients. Attempts have been made to combine stem cell therapy and acupuncture to treat stroke patients and have shown the promising results. This prospective review will look into the possible mechanisms of stem cell therapy and acupuncture and intend to undercover the potential benefit of the combined therapy. It intends to bridge the modern emerging stem cell therapy and traditional acupuncture at cellular and molecular levels and to demonstrate the potential benefit to improve clinical outcomes.

Perfused Three-dimensional Organotypic Culture of Human Cancer Cells for Therapeutic Evaluation.

Pharmaceutical research requires pre-clinical testing of new therapeutics using both in-vitro and in-vivo models. However, the species specificity of non-human in-vivo models and the inadequate recapitulation of physiological conditions in-vitro are intrinsic weaknesses. Here we show that perfusion is a vital factor for engineered human tissues to recapitulate key aspects of the tumour microenvironment. Organotypic culture and human tumour explants were allowed to grow long-term (14-35 days) and phenotypic features of perfused microtumours compared with those in the static culture. Differentiation status and therapeutic responses were significantly different under perfusion, indicating a distinct biological response of cultures grown under static conditions. Furthermore, heterogeneous co-culture of tumour and endothelial cells demonstrated selective cell-killing under therapeutic perfusion versus episodic delivery. We present a perfused 3D microtumour culture platform that sustains a more physiological tissue state and increased viability for long-term analyses. This system has the potential to tackle the disadvantages inherit of conventional pharmaceutical models and is suitable for precision medicine screening of tumour explants, particularly in hard-to-treat cancer types such as brain cancer which suffer from a lack of clinical samples.

Three-dimensional perfused tumour spheroid model for anti-cancer drug screening.

OBJECTIVE: To build an in vitro-perfused, three-dimensional (3D) spheroid model based on the TissueFlex system for anti-cancer drug efficacy testing in order to mimic avascular micro-tissues with inherent O2, nutrient and metabolite gradients, and to provide a more accurate prediction of drug toxicity and efficacy than traditional in vitro tumour models in conventional static culture well plates. RESULTS: The perfused cancer spheroid model showed higher cell viability and increased diameter of spheroids over a relatively long culture period (17 days). Three anti-cancer drugs with different cytotoxic mechanisms were tested. In perfusion, lower cytotoxicity was observed for traditional cytotoxic drug 5-fluorouracil and microtubule-interfering, paclitaxel, showed greater interruption of spheroid integrity. For the hypoxic-dependent drug, tirapazamine, there was no significant difference observed between static and perfusion cultures. CONCLUSION: The perfusion culture provides a better homeostasis for cancer cell growth in a more controllable working platform for long-term drug testing.

Study of neuroprotective function of Ginkgo biloba extract (EGb761) derived-flavonoid monomers using a three-dimensional stem cell-derived neural model.

An in vitro three-dimensional (3D) cell culture system that can mimic organ and tissue structure and function in vivo will be of great benefit for drug discovery and toxicity testing. In this study, the neuroprotective properties of the three most prevalent flavonoid monomers extracted from EGb 761 (isorharmnetin, kaempferol, and quercetin) were investigated using the developed 3D stem cell-derived neural co-culture model. Rat neural stem cells were differentiated into co-culture of both neurons and astrocytes at an equal ratio in the developed 3D model and standard two-dimensional (2D) model using a two-step differentiation protocol for 14 days. The level of neuroprotective effect offered by each flavonoid was found to be aligned with its effect as an antioxidant and its ability to inhibit Caspase-3 activity in a dose-dependent manner. Cell exposure to quercetin (100 µM) following oxidative insult provided the highest levels of neuroprotection in both 2D and 3D models, comparable with exposure to 100 µM of Vitamin E, whilst exposure to isorhamnetin and kaempferol provided a reduced level of neuroprotection in both 2D and 3D models. At lower dosages (10 µM flavonoid concentration), the 3D model was more representative of results previously reported in vivo. The co-cultures of stem cell derived neurons and astrocytes in 3D hydrogel scaffolds as an in vitro neural model closely replicates in vivo results for routine neural drug toxicity and efficacy testing. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:735-744, 2016.

Development of in vitro 3D TissueFlex® islet model for diabetic drug efficacy testing.

Increasing individuals diagnosed with type II diabetes pose a strong demand for the development of more effective anti-diabetic drugs. However, expensive, ethically controversial animal-based screening for anti-diabetic compounds is not always predictive of the human response. The use of in vitro cell-based models in research presents obviously ethical and cost advantages over in vivo models. This study was to develop an in vitro three-dimensional (3D) perfused culture model of islets (Islet TF) for maintaining viability and functionality longer for diabetic drug efficacy tests. Briefly fresh isolated rat islets were encapsulated in ultrapure alginate and the encapsulated islets were cultured in TissueFlex(®), a multiple, parallel perfused microbioreactor system for 7 days. The encapsulated islets cultured statically in cell culture plates (3D static) and islets cultured in suspension (2D) were used as the comparisons. In this study we demonstrate for the first time that Islet TF model can maintain the in vitro islet viability, and more importantly, the elevated functionality in terms of insulin release and dynamic responses over a 7-day culture period. The Islet TF displays a high sensitivity in responding to drugs and drug dosages over conventional 2D and 3D static models. Actual drug administration in clinics could be simulated using the developed Islet TF model, and the patterns of insulin release response to the tested drugs were in agreement with the data obtained in vivo. Islet TF could be a more predictive in vitro model for routine short- and long-term anti-diabetic drug efficacy testing.

Protocatechuic acid promotes cell proliferation and reduces basal apoptosis in cultured neural stem cells.

Protocatechuic acid (PCA), a phenolic compound isolated from the kernels of Alpinia oxyphylla, showed anti-oxidant neuroprotective property in our previous study. However, it is still unknown whether PCA have effects on the cultured neural stem cells (NSCs). In this study, we investigated the roles of PCA in the survival and apoptosis of rat NSCs under normal conditions. NSCs obtained from 13.5-day-old rat embryos were propagated as neurospheres and cultured under normal conditions with or without PCA for 4 and 7 days. The cell viability was determined by the cell counting kit-8 (CCK-8) test, while cell proliferation was assayed by bromodeoxyuridine (BrdU) labeling. PCA increased the cellular viability of NSCs and stimulated cell proliferation in a dose- and time-dependent manner. Apoptotic cells were detected after 4 days by observing the nuclear morphological changes and flow cytometric analysis. Compared with the control on both culture days, treatment with PCA effectively reduced the levels of apoptosis of NSCs. At the same time, the reactive oxygen species (ROS) level in NSCs was depressed. In addition, PCA also significantly decreased the activity of elevated caspase-3, indicating that PCA may inhibit apoptosis of NSCs via suppression of the caspase cascade. These results suggest that PCA may be a potential growth inducer and apoptosis inhibitor for NSCs.

Effects of encapsulated rabbit mesenchymal stem cells on ex vivo expansion of human umbilical cord blood hematopoietic stem/progenitor cells.

The expansion of umbilical cord blood mononuclear cells (UCB MNCs) was investigated in a novel co-culture system by means of encapsulation of rabbit bone marrow (BM) mesenchymal stem cells (MSCs) in alginate beads (Alg beads). Three kinds of media were applied and the experiments lasted for 7 days. The total nucleated cell density was measured every 24 h. Flow cytometric assay for CD34(+) cells and methylcellulose colony assays were carried out at 0, 72 and 168 h. It was found that the encapsulated MSCs illustrated remarkable effects on UCB MNCs expansion regardless of whether serum is present in culture media or not. At the end of 168 h co-culture, the total nucleated cell number was multiplied by 15 +/- 2.9 times, and CD34(+) cells 5.3 +/- 0.3 times and colony-forming units in culture (CFU-Cs) 5.6 +/- 1.2 times in the serum-free media supplemented with conventional dose of cytokines, which was very similar to the results in the containing 20% serum media. While in the control, i.e. MNC expansion without encapsulated MSCs, however, total nucleated cells density changed mildly, CD34(+) cells and CFU-Cs showed little effective expansion. It is demonstrated that the encapsulated stromal cells can support the expansion of UCB MNCs effectively under the experimental condition.