Proceedings of the first academic symposium on developing, qualifying and operating a cell and gene therapy manufacturing facility.

A significant portion of the more than 1000 candidate cell and gene therapy products currently under clinical investigation (clinicaltrials.gov) are born out of academic research centers affiliated with universities, hospitals and non-profit research institutions. Supporting these efforts are myriad academic clinical materials production facilities with more than 40 such facilities currently operational in the United States alone. In March 2018, Stanford University's Laboratory for Cell and Gene Therapy held a symposium with the leaders and staff of more than 25 similar facilities to discuss the collective experience in developing, qualifying and operating cell and gene therapy manufacturing facilities according to current Good Manufacturing Practices. Topics included facility design, construction, staffing and operations and compliance. Leaders from several institutions gave overviews of the history of development of the facilities and discussed challenges and opportunities they had experienced over the past 10-20 years of operations. Working sessions were also held to discuss specific aspects of Process Development, Manufacturing, Quality Systems, Regulatory Affairs and Business Development with all participants contributing to the discussions. We summarize here the findings of this inaugural meeting with an emphasis on best practices and suggested guidelines for operations.

Structure-Based Virtual Screening Identifying Novel FOXM1 Inhibitors as the Lead Compounds for Glioblastoma.

BACKGROUND: Glioblastoma multiforme (GBM) is a highly heterogeneous brain tumor with limited treatment options and a poor prognosis. Cancer stem cells (CSCs) have emerged as a critical factor in GBM resistance and management, contributing to tumor growth, heterogeneity, and immunosuppression. The transcription factor FOXM1 has been identified as a key player in the progression, spread, and therapy resistance of various cancers, including GBM. OBJECTIVE: In this research, the objective was to perform structure-based in silico screening with the aim of identifying natural compounds proficient in targeting the DNA-binding domain (DBD) of the FOXM1 protein. METHODS: In this study, in silico tools were employed for screening a hundred naturally occurring compounds capable of targeting the FOXM1 protein. Through molecular docking analysis and pharmacokinetic profiling, five compounds were found to be promising candidates for extensive interaction with the FOXM1 protein. Further, these compounds were validated for the stability of the FOXM1-natural compound complex using molecular dynamics (MD) simulations. RESULTS: Four compounds, such as Withaferin A, Bryophyllin A, Silybin B, Sanguinarine and Troglitazone (control compound), emerged as promising candidates with substantial interactions with FOXM1, suggesting their potential as a protein inhibitor based on molecular docking investigations. After MD simulation analysis, the FOXM1- Bryophyllin A complex was found to maintain the highest stability, and the other three ligands had moderate but comparable binding affinities over a period of 100 ns. CONCLUSION: This study provides valuable insights into four promising FOXM1 inhibitors that have the ability to induce senescence in GBM stem cells. These findings contribute to the development of structure-based designing strategies for FOXM1 inhibitors and innovative therapeutic approaches for the treatment of Glioblastoma.

Harmonization of Zika serological assays and comparative evaluation of two commercial ZIKA IgG ELISA kits.

The interpretation for Zika virus serology results is challenging due to high antibody cross reactivity with other flaviviruses. This limits availability of reliable and accurate methods for serosurveillance studies to understand the disease burden. Therefore, we conducted study to harmonize anti-Zika IgG antibody detection assays with 1st WHO International Standard (16/352) and working standard (16/320) for anti-Zika virus antibody.Additionally, evaluated NuGenTMZIKA-IgG and NovaLisa®ZIKA virus IgG-Capture ELISA using a panel of 278 seraFurther, 106 samples positive for other-flavi viruses were taken for assessing cross-reactivity of the assay, all serums were further tested by Zika-PRNT. The results of this study indicates satisfactory performance of both the assays. Serological and neutralization assays were calibrated according to the international standards. This will help in understanding antibody dynamics in serosurveillance and vaccine studies. However the performance of the kits with possibilities of cross-reactivity will have to be verified by coupling ZIKV and DENV specific ELISA.

Cannabidiol and Neurodegeneration: From Molecular Mechanisms to Clinical Benefits.

Neurodegenerative disorders (NDs) such as Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, and amyotrophic lateral sclerosis are severe and life-threatening conditions in which significant damage of functional neurons occurs to produce malfunction of psycho-motor functions. NDs are an important cause of death in the elderly population worldwide. These disorders are commonly associated with the progression of age, oxidative stress, and environmental pollutants, which are the major etiological factors. Abnormal aggregation of specific proteins such as α-synuclein, amyloid-ß, huntingtin, and tau, and accumulation of its associated oligomers in neurons are the hallmark pathological features of NDs. Existing therapeutic options for NDs are only symptomatic relief and do not address root-causing factors, such as protein aggregation, oxidative stress, and neuroinflammation. Cannabidiol is a non-psychotic natural cannabinoid obtained from Cannabis sativa that possesses multiple pharmacological actions, including antioxidant, anti-inflammatory, and neuroprotective effects in various NDs and other neurological disorders both in vitro and in vivo. Cannabidiol has gained attention as a promising therapeutic drug candidate for the management of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease, by inhibiting protein aggregation, free radicals, and neuroinflammation. In parallel, CBD has shown positive results in other neurological disorders, such as epilepsy, depression, schizophrenia, and anxiety, as well as adjuvant treatment with existing standard therapeutic agents. Hence, the present review focuses on exploring the possible molecular mechanisms in controlling various neurological disorders as well as its clinical applications in NDs including epilepsy, depression and anxiety. In this way, the current review will serve as a standalone reference for the researchers working in this area.

Regenerative Endodontics-Reviving the Pulp the Natural Way: A Case Report.

Regenerative endodontic therapy (RET) offers a novel treatment option for developing teeth with pulp necrosis. In the current instance, RET was used to treat an immature mandibular permanent first molar that had been identified with irreversible pulpitis. The root canals were treated with triple antibiotic paste (TAP) and 1.5% sodium hypochlorite (NaOCl) irrigation. TAP was removed, and 17% ethylenediaminetetraacetic acid (EDTA) was used to treat the root canals during the second visit. As a scaffold, Platelet-rich fibrin (PRF) was applied. Mineral trioxide aggregate (MTA) was applied over PRF, and composite resin was used to repair the teeth. Radiographs taken from the posterior were utilized to assess the healing. The teeth displayed no signs of pain and healing after the six-month follow-up periods, and pulp sensibility tests using a cold and electric pulp tester produced no results. Conservative treatment options should be considered to save immature permanent teeth and assist in the regeneration of the root apex.

External quality assurance of serological diagnosis of dengue, chikungunya and Japanese encephalitis virus infection.

Introduction: Dengue, chikungunya and Japanese encephalitis are the most common arthropod-borne viral diseases in India. Due to overlapping clinical symptoms, accurate, high-quality and timely laboratory-based differential diagnosis is essential for control and containment of outbreaks. This is most commonly done by detection of IgM antibodies in serum using enzyme-linked immunosorbent assays. The Resource Centre for Virus Research and Diagnostic Laboratories (VRDLs) in Pune, India organized an external quality assurance (EQA) study to check the accuracy of serological diagnostics in the VRDL network. Methods: Three panels, one each for anti-dengue virus, anti-chikungunya virus and anti-Japanese encephalitis virus IgM antibodies, comprising six human serum samples (two positive and four negative) were distributed to test the sensitivity, specificity and reproducibility of serological testing in 124 VRDLs across India in 2018-19 and 2019-20. Results: Among the 124 VRDLs, the average concordance for both 2018-19 and 2019-20 was 98%. In 2018-19, 78.33%, 13.33% and 6.66% of VRDLs reported 100% concordance, 91-99% concordance and 81-90% concordance with the reference results, respectively, and 1.66% of VRDLs had concordance <80%. In 2019-20, 79.68%, 14.06% and 4.68% of VRDLs reported 100% concordance, 91-99% concordance and 81-90% concordance with the reference results, respectively, and 1.56% of VRDLs had concordance <80%. Conclusion: The EQA programme was beneficial for assessing and understanding the performance of the VRDLs. The study data indicate good proficiency in serological diagnosis of dengue, chikungunya and Japanese encephalitis in the VRDL network laboratories. Further expansion of the EQA programme to cover other viruses of public health importance will increase confidence among the VRDL network, and generate evidence of high-quality testing.

Applications of Silver Nanoparticles in Pediatric Dentistry: An Overview.

Nanoscience and nanotechnology are emerging fields involved in the synthesis and application of nanoscale materials and structures. Metallic nanoparticles and metallic oxide are being used extensively in dentistry as they interfere with bacterial metabolism and prevent biofilm formation. AgNPs are a class of zero-dimensional materials with distinctive morphologies. The metallic nanoparticles demonstrate the significant antimicrobial activity by ion release, oxidative stress induction, and non-oxidative mechanisms. Metallic silver has been known for its antimicrobial activity since ancient times. Through the years, silver-containing compounds have been used in various forms to treat several medical conditions. Incorporating silver nanoparticles into dental materials may enhance the mechanical features and antibacterial properties of dental materials. Therefore, an increasing number of dental materials with the inclusion of silver nanoparticles are being developed that improve the overall oral health status of patients. This paper aims to review the literature on specific characteristics of silver nanoparticles and their applications in pediatric dentistry.

Antioxidants in Alzheimer's Disease: Current Therapeutic Significance and Future Prospects.

Alzheimer's disease (AD) rate is accelerating with the increasing aging of the world's population. The World Health Organization (WHO) stated AD as a global health priority. According to the WHO report, around 82 million people in 2030 and 152 million in 2050 will develop dementia (AD contributes 60% to 70% of cases), considering the current scenario. AD is the most common neurodegenerative disease, intensifying impairments in cognition, behavior, and memory. Histopathological AD variations include extracellular senile plaques' formation, tangling of intracellular neurofibrils, and synaptic and neuronal loss in the brain. Multiple evidence directly indicates that oxidative stress participates in an early phase of AD before cytopathology. Moreover, oxidative stress is induced by almost all misfolded protein lumps like α-synuclein, amyloid-ß, and others. Oxidative stress plays a crucial role in activating and causing various cell signaling pathways that result in lesion formations of toxic substances, which foster the development of the disease. Antioxidants are widely preferred to combat oxidative stress, and those derived from natural sources, which are often incorporated into dietary habits, can play an important role in delaying the onset as well as reducing the progression of AD. However, this approach has not been extensively explored yet. Moreover, there has been growing evidence that a combination of antioxidants in conjugation with a nutrient-rich diet might be more effective in tackling AD pathogenesis. Thus, considering the above-stated fact, this comprehensive review aims to elaborate the basics of AD and antioxidants, including the vitality of antioxidants in AD. Moreover, this review may help researchers to develop effectively and potentially improved antioxidant therapeutic strategies for this disease as it also deals with the clinical trials in the stated field.

Advances in stromal cell therapy for management of Alzheimer's disease.

Deposition of misfolded proteins and synaptic failure affects the brain in Alzheimer's disease (AD). Its progression results in amnesia and cognitive impairment. Absence of treatment is due to excessive loss of neurons in the patients and the delayed effects of drugs. The enhanced pluripotency, proliferation, differentiation, and recombination characteristics of stromal cells into nerve cells and glial cells present them as a potential treatment for AD. Successful evidence of action in animal models along with positive results in preclinical studies further encourage its utilization for AD treatment. With regard to humans, cell replacement therapy involving mesenchymal stromal cells, induced-pluripotent stromal cells, human embryonic stromal cells, and neural stems show promising results in clinical trials. However, further research is required prior to its use as stromal cell therapy in AD related disorders. The current review deals with the mechanism of development of anomalies such as Alzheimer's and the prospective applications of stromal cells for treatment.

Exploring state-of-the-art advances in targeted nanomedicines for managing acute and chronic inflammatory lung diseases.

Diagnosis and treatment of lung diseases pose serious challenges. Currently, diagnostic as well as therapeutic methods show poor efficacy toward drug-resistant bacterial infections, while chemotherapy causes toxicity and nonspecific delivery of drugs. Advanced treatment methods that cure lung-related diseases, by enabling drug bioavailability via nasal passages during mucosal formation, which interferes with drug penetration to targeted sites, are in demand. Nanotechnology confers several advantages. Currently, different nanoparticles, or their combinations, are being used to enhance targeted drug delivery. Nanomedicine, a combination of nanoparticles and therapeutic agents, that delivers drugs to targeted sites increases the bioavailability of drugs at these sites. Thus, nanotechnology is superior to conventional chemotherapeutic strategies. Here, the authors review the latest advancements in nanomedicine-based drug-delivery methods for managing acute and chronic inflammatory lung diseases.

Silybin B and Cianidanol Inhibit Mpro and Spike Protein of SARS-CoV-2: Evidence from in silico Molecular Docking Studies.

BACKGROUND: The main proteases (Mpro) and Spike Proteins (SP) of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) play a major role in viral infection development by producing several non-structural proteins (nsPs) and penetrating the host cells, respectively. In this study, the potential of in silico molecular docking-based drug repositioning approach was exploited for identifying the inhibitors of Mpro and SP of SARS-CoV-2. METHODS: A total of 196 compounds, including various US-FDA-approved drugs, vitamins, and their analogs, were docked with Mpro (PDB IDs: 6YB7 and 6Y84), and the top six ligands were further tested for ADME properties, followed by docking with SP (PDB IDs: 6LXT and 6W41). RESULTS: Out of 196 compounds, binding energy (DE) of Silybin B (6YB7: DE: -11.20 kcal/mol; 6Y84: DE: - 10.18 kcal/mol; 6LXT: DE: -10.47 kcal/mol; 6W41: DE: -10.96 kcal/mol) and Cianidanol (6YB7: DE: -8.85 kcal/mol; 6LXT: DE: -9.36 kcal/mol; 6Y84: DE: -10.02 kcal/mol; 6W41: DE: -9.52 kcal/mol) demonstrated better binding and ADME properties compared with the currently endeavored drugs like Hydroxychloroquine and Lopinavir. Additionally, Elliptinone, Diospyirin, SCHEMBL94263, and Fiboflavin have shown encouraging results. Fiboflavin, an immunity booster, was found to inhibit both the Mpro and spike protein of SARSCoV- 2. It was observed that amino acid residues MET6, ALA7, PHE8, PRO9, ASP295, GLY302, VAL303, and THR304 play significant roles in protein-ligand interactions through hydrogen bonds and Vander Waals forces. CONCLUSION: Silybin B and Cianidanol showed excellent binding and ADME properties compared with the currently endeavored drugs and can be exploited as therapeutic options against SARS-CoV-2 infection after experimental validation and clinical trials.

Advances in pulmonary drug delivery targeting microbial biofilms in respiratory diseases.

The increasing burden of respiratory diseases caused by microbial infections poses an immense threat to global health. This review focuses on the various types of biofilms that affect the respiratory system and cause pulmonary infections, specifically bacterial biofilms. The article also sheds light on the current strategies employed for the treatment of such pulmonary infection-causing biofilms. The potential of nanocarriers as an effective treatment modality for pulmonary infections is discussed, along with the challenges faced during treatment and the measures that may be implemented to overcome these. Understanding the primary approaches of treatment against biofilm infection and applications of drug-delivery systems that employ nanoparticle-based approaches in the disruption of biofilms are of utmost interest which may guide scientists to explore the vistas of biofilm research while determining suitable treatment modalities for pulmonary respiratory infections.

Clinical efficacy of amino bisphosphonate on periodontal disease status in postmenopausal women: Randomized double-blind placebo-controlled trial.

OBJECTIVES: Osteoporosis is a common skeletal disorder affecting postmenopausal women. Data suggest that postmenopausal women are at increased risk of periodontal diseases. Amino bisphosphonates are potent inhibitors of bone resorption and effectively used in the treatment of osteoporosis. Preliminary data indicate that there is a potential role for bisphosphonates in the management of periodontitis. Hence, this randomized placebo-controlled trial was designed to investigate the clinical efficacy of amino bisphosphonate on periodontal disease status among postmenopausal women. MATERIALS AND METHODS: Thirty patients were randomly allocated to two treatment groups: Group A, which received scaling and root debridement and 70 mg weekly single oral dose of alendronate drug, and Group B, which received scaling and root debridement and placebo drug for 6 months. Clinical periodontal measurements were carried out for all patients at the baseline and 6 months later. Mandibular bone mineral density (BMD) was measured using a dual energy X-ray absorptiometer at the beginning of the study and the end of 6 months. RESULTS: A weekly single oral dose of 70 mg alendronate was well-tolerated. The intragroup comparison showed significant improvement in periodontal parameters in both groups. The intergroup comparison showed a significant increase in BMD after 6 months in Group A when compared with Group B (P = 0.0179). CONCLUSION: Single oral dose of 70 mg alendronate per week is well-tolerable, gastro-intestinally safe, and improves the clinical outcome of nonsurgical periodontal therapy.

Comparative evaluation of a novel herbal anesthetic gel and 2% lignocaine gel as an intraoral topical anesthetic agent in children: Bilateral split-mouth, single-blind, crossover in vivo study.

BACKGROUND: Topical anesthetics have an intrinsic part to reduce pricking pain sensation due to needle stick before injection in children. AIM: The present study aimed to determine the effectiveness of a novel herbal anesthetic gel used as a topical anesthetic before an inferior alveolar nerve block. SETTINGSANDDESIGN: This was a bilateral split-mouth, single blind, crossoverin vivo study. METHODS: Atotal number of 30 children were selected for this study design. After the application of the topical anesthesia, a 26-gauge needle was inserted in the mucobuccal fold and local anesthetic solution was deposited. Assessment of pain perception was done before the procedure and at the time of needle penetration using hemodynamic parameters such as blood pressure and heart rate. The objective and subjective pain assessment was recoded through sound eye motor scale and Faces Pain Scale-Revised (FPS-R). STATISTICALANALYSIS: As the data followed a normal distribution, parametric tests were used to analyze these data. The independent sample t-test and paired sample t-test were used to check the mean differences. RESULTS: The data showed no statistically significant differences in the objective and subjective pain assessment values of the novel herbal anesthetic gel compared to the 2% lignocaine gel. However, the intragroup comparisons of the before and during treatment results showed statistically significant results (P < 0.05). CONCLUSION: The novel herbal anesthetic gel was effective and safe in reducing the pain from needle insertion. Thus, setting up scientific evidence for the therapeutic usage of herbal products can, therefore, assist to develop a more efficient and alternative topical anesthetic.

Identification and phylogenetic analysis of herpes simplex virus-1 from clinical isolates in India.

Human herpes simplex virus (HSV)-1 infection is acquired in childhood and persists throughout a person's lifetime. Here, we present two cases from India; one showing symptoms of postpartum haemorrhage with disseminated intravascular coagulation, and the second one showing signs of acute encephalitis syndrome. The aetiological agent in both cases was identified as HSV-1 using the PCR method. The next-generation sequencing method retrieved ~97 % of the viral genome from the isolates of the clinical samples. The phylogenetic analysis of the retrieved genomes revealed that they belong to clade II of HSV-1. This study identifies a few sequence variations in the glycoprotein region of HSV-1 during two different clinical manifestations. There are a couple of papers that analyse variations in the glycoprotein region of clinical samples. Further, this study also highlights the importance of considering HSV-1 during differential diagnosis when analysing the nosocomial infection.

Burden of dengue infection in India, 2017: a cross-sectional population based serosurvey.

BACKGROUND: The burden of dengue virus (DENV) infection across geographical regions of India is poorly quantified. We estimated the age-specific seroprevalence, force of infection, and number of infections in India. METHODS: We did a community-based survey in 240 clusters (118 rural, 122 urban), selected from 60 districts of 15 Indian states from five geographical regions. We enumerated each cluster, randomly selected (with an Andriod application developed specifically for the survey) 25 individuals from age groups of 5-8 years, 9-17 years, and 18-45 years, and sampled a minimum of 11 individuals from each age group (all the 25 randomly selected individuals in each age group were visited in their houses and individuals who consented for the survey were included in the study). Age was the only inclusion criterion; for the purpose of enumeration, individuals residing in the household for more than 6 months were included. Sera were tested centrally by a laboratory team of scientific and technical staff for IgG antibodies against the DENV with the use of indirect ELISA. We calculated age group specific seroprevalence and constructed catalytic models to estimate force of infection. FINDINGS: From June 19, 2017, to April 12, 2018, we randomly selected 17 930 individuals from three age groups. Of these, blood samples were collected and tested for 12 300 individuals (5-8 years, n=4059; 9-17 years, n=4265; 18-45 years, n=3976). The overall seroprevalence of DENV infection in India was 48·7% (95% CI 43·5-54·0), increasing from 28·3% (21·5-36·2) among children aged 5-8 years to 41·0% (32·4-50·1) among children aged 9-17 years and 56·2% (49·0-63·1) among individuals aged between 18-45 years. The seroprevalence was high in the southern (76·9% [69·1-83·2]), western (62·3% [55·3-68·8]), and northern (60·3% [49·3-70·5]) regions. The estimated number of primary DENV infections with the constant force of infection model was 12 991 357 (12 825 128-13 130 258) and for the age-dependent force of infection model was 8 655 425 (7 243 630-9 545 052) among individuals aged 5-45 years from 30 Indian states in 2017. INTERPRETATION: The burden of dengue infection in India was heterogeneous, with evidence of high transmission in northern, western, and southern regions. The survey findings will be useful in making informed decisions about introduction of upcoming dengue vaccines in India. FUNDING: Indian Council of Medical Research.

Identification of Ellagic acid analogues as potent inhibitor of protein Kinase CK2:A chemopreventive role in oral Cancer.

Over expression of Protein kinase (CK2) suppresses apoptosis induced by a variety of agents, whereas down-regulation of CK2 sensitizes cells to induction of apoptosis. In this study, we have built quantitative structure activity relationship (QSAR) models, which were trained and tested on experimentally verified 38 enzyme׳s inhibitors having inhibitory value IC50 in µM. These inhibitors were docked at the active site of CK2 (PDB id: 2ZJW) using AutoDock software, which resulted in energy-based descriptors such as binding energy, intermol energy, torsional energy, internal energy and docking energy. For QSAR modeling, Multiple Linear Regression (MLR) model was engendered using energy-based descriptors yielding correlation coefficient r(2) of 0.4645. To assess the predictive performance of QSAR models, different cross-validation procedures were adopted. Our results suggests that ligand-receptor binding interactions for CK2 employing QSAR modeling seems to be a promising approach for prediction of IC50 value of a new ligand molecule against CK2.Further, twenty analogues of ellagic acid were docked with CK2 structure. After docking, two compounds CID 46229200 and CID 10003463 had lower docking energy even lower than standard control Ellagic acid with CK2 was selected as potent candidate drugs for Oral cancer. The biological activity of two compounds in terms of IC50 was predicted based on QSAR model, which could be used as a guideline for anticancerous activity of compounds before their synthesis.

Drug induced gingival overgrowth: a rare case report.

Gingival overgrowth is well documented side effect associated with three major classes of drugs viz, anticonvulsants, calcium channel blockers, and immunosuppressants. Despite our greater understanding of pathogenesis of Drug induced Gingival Overgrowth (DIGO), its treatment still remains a challenge for the periodontists and treatment is still largely limited to maintenance of improved level of oral hygiene and surgical removal of overgrown tissue. Dental Surgeons need to discuss this issue with their medical colleagues and to practice care while prescribing the drugs associated with gingival overgrowth. The aim of present article is to report a rare case where even after extraction of all teeth; the enlargement did not subsided for one month.

Differentiation of oligodendrocyte progenitor cells from human embryonic stem cells on vitronectin-derived synthetic peptide acrylate surface.

Human embryonic stem cell (hESC)-derived oligodendrocyte progenitor cells (OPCs) are being studied for cell replacement therapies, including the treatment of acute spinal cord injury. Current methods of differentiating OPCs from hESCs require complex, animal-derived biological extracellular matrices (ECMs). Defined, low-cost, robust, and scalable culture methods will need to be developed for the widespread deployment and commercialization of hESC-derived cell therapies. Here we describe a defined culture system that uses a vitronectin-derived synthetic peptide acrylate surface (VN-PAS; commercially available as Corning(®) Synthemax(®) surface) in combination with a defined culture medium for hESC growth and differentiation to OPCs. We show that synthetic VN-PAS supports OPC attachment and differentiation, and that hESCs grown on VN-PAS are able to differentiate into OPCs on VN-PAS. Compared to OPCs derived from hESCs grown on ECM of animal origin, higher levels of NG2, a chondroitin sulfate proteoglycan expressed by OPCs, were observed in OPCs differentiated from H1 hESCs grown on VN-PAS, while the expression levels of Nestin and PDGFRα were comparable. In summary, this study demonstrates that synthetic VN-PAS can replace complex, animal-origin ECM to support OPC differentiation from hESCs.