A Calvarial Defect Model to Investigate the Osteogenic Potential of Umbilical Cord Stem Cells in Bone Regeneration.

BACKGROUND: The standard graft material for alveolar cleft repair (ACR) is autogenous iliac crest. A promising alternative potential graft adjunct-newborn human umbilical cord mesenchymal stem cells (h-UCMSCs)-has yet to be explored in vivo. Their capacity for self-renewal, multipotent differentiation, and proliferation allows h-UCMSCs to be harnessed for regenerative medicine. This study sought to evaluate the efficacy of using tissue-derived h-UCMSCs and their osteogenic capabilities to improve ACR in a murine model. METHODS: Foxn1 mice were separated into three groups with the following calvarial defects: no treatment (empty defect; n = 6), poly(D,L-lactide-co-glycolide) (PLGA) scaffold ( n = 6), or h-UCMSCs with PLGA ( n = 4). Bilateral 2-mm-diameter parietal bone critical-sized defects were created using a dental drill. Microcomputed tomography (microCT) imaging was performed 1, 2, 3, and 4 weeks postoperatively. The mice were euthanized 4 weeks postoperatively for RNAScope, immunohistochemical, and histological analysis. RESULTS: No mice experienced complications during the follow-up period. MicroCT imaging and histological analysis demonstrated that the no-treatment and PLGA-only defects remained patent without significant defect size differences across groups. In contrast, the h-UCMSCs with PLGA group had significantly greater bone fill on microCT and histological analysis. CONCLUSIONS: This study demonstrates a successful calvarial defect model for the investigation of h-UCMSC-mediated osteogenesis and bone repair. Evidence reveals that PLGA alone has neither short-term effects on bone formation nor any unwanted side effects, making it an attractive scaffold. Further investigation using h-UCMSCs with PLGA in larger animals is warranted to advance future translation to patients requiring ACR. CLINICAL RELEVANCE STATEMENT: The authors' results demonstrate a successful murine calvarial defect model for the investigation of h-UCMSC-mediated osteogenesis and bone repair, and they provide preliminary evidence for the safe and efficacious use of this graft adjunct in alveolar cleft repair.

Comparison of umbilical cord tissue-derived mesenchymal stromal cells isolated from cryopreserved material and extracted by explantation and digestion methods utilizing a split manufacturing model.

BACKGROUND AIMS: Umbilical cord (UC) tissue is recognized as an advantageous source of mesenchymal stromal cells (MSCs), whose therapeutic properties are being actively evaluated in pre-clinical and clinical trials. In recognition of its potential value, storage of UC tissue or cells from UC tissue in newborn stem cell banks is now commonplace; however, strategies for isolating UC-derived MSCs (UCMSCs) from UC tissue have not been standardized. The majority of newborn stem cell banks take one of two approaches to cord tissue processing and cryopreservation: enzymatic digestion of the fresh tissue with cryopreservation of the subsequent cell suspension or cryopreservation of the tissue as a composite whole with later, post-thaw isolation of cells by explantation. Evaluation of UCMSCs derived by these two principal preparation and cryopreservation strategies is important to understanding whether the methods currently employed by newborn stem cell banks retain the desirable clinical attributes of UC cells. METHODS: UCMSCs were isolated from 10 UC tissue samples by both explantation and enzymatic digestion methods to allow for comparison of cells from the same donor. Cell isolates from both methods were compared pre- and post-cryopreservation as well as after serial passaging. Cell viability, morphology, growth kinetics, immunophenotype, cytokine secretion and differentiation capacity were evaluated. RESULTS: UCMSCs could be derived from fresh UC tissue by both explantation and digestion methods and from thawed UC tissue by explantation. Initial cell populations isolated by digestion were heterogeneous and took longer to enrich for UCMSCs in culture than populations obtained by explantation. However, once isolated and enriched, UCMSCs obtained by either method showed no significant difference in viability, morphology, rate of proliferation, surface marker expression, levels of cytokine secretion or differentiation capacity. CONCLUSIONS: Derivation of UCMSCs by explantation after thawing UC cryopreserved as a composite tissue may be favorable in terms of initial purity and number of cells achievable by a specific passage. However, we observed no evidence of functional difference between UCMSCs derived by explanation or digestion, suggesting that cells isolated from cryopreserved material obtained by either method maintain their therapeutic properties.

Racial diversity in abortion education and intention to provide abortion in postresidency practice: data from the Ryan Program.

BACKGROUND: In 2011, 38% of US reproductive-aged women lived in the 89% of counties with no abortion provider. Physicians from racial and ethnic minority backgrounds (black, Latino, Native American, and Asian American) are more likely than white physicians to practice in underserved areas and serve patients who are poor or minorities. Abortion patients are racially diverse. However, we know little about racial and ethnic makeup of abortion providers and the differences in physicians' interest in providing abortions. OBJECTIVE: The objective of the study was to examine racial differences in participation in abortion training and intention to provide abortion in postresidency practice. STUDY DESIGN: This is a cross-sectional study of Ryan Program residents after completing a family-planning rotation. The Ryan Program supports obstetrics-gynecology residency programs to incorporate routine abortion care into training. Since 2003 the Ryan Residency Program has administered postrotation resident surveys, and race/ethnicity was added in 2015. We assessed correlates of intention to provide abortion, specifically comparing minorities with whites and whether training participation varied by race. We conducted a modified mediation analysis to assess the role of potential mediators in the relationship between race and intention to provide abortion. RESULTS: A total of 777 residents (79.0%) responded from September 2015 through August 2018. The proportions were as follows: 64.9% white, 8.5% black, 4.1% Hispanic/Latino, 18.8% Asian, and 3.8% as other. Overall, 56.9% intended to provide abortion for all indications and 82.4% for pregnancy complications. In a univariate analysis, Asian residents were significantly more likely to intend to provide abortions for all indications compared with white residents (68.4% vs 56.0%, odds ratio, 1.69, confidence interval, 1.13-2.53). This difference was not significant when controlling for religiosity and abortion attitudes. Religiosity (odds ratio, 0.60, confidence interval, 0.47-0.77) and abortion attitude (odds ratio, 3.32, confidence interval, 2.48-4.44) were significantly correlated with intention to provide abortion for nonmedical indications after residency. In a modified mediation analysis, the relationship between race and intention to provide was mediated by religiosity for black residents and abortion attitude for Asian residents. There was no difference in participation in abortion training by race/ethnicity. CONCLUSION: Racial differences in intention to provide abortion in postresidency practice are mediated by religiosity and abortion attitude. Better understanding the intricate relationships between race, religiosity, participation in training, and future practice will allow us to improve abortion training while paving the way to support a more diverse abortion provider workforce.

Human umbilical cord blood cells restore vascular integrity in injured rat brain and modulate inflammation in vitro.

Aim: Traumatic brain injury is a complex condition consisting of a mechanical injury with neurovascular disruption and inflammation with limited clinical interventions available. A growing number of studies report systemic delivery of human umbilical cord blood (HUCB) as a therapy for neural injuries. Materials & methods: HUCB cells from five donors were tested to improve blood-brain barrier integrity in a traumatic brain injury rat model at a dose of 2.5 × 107 cells/kg at 24 or 72 h postinjury and for immunomodulatory activity in vitro. Results & Conclusion: We observed that cells delivered 72 h postinjury significantly restored blood-brain barrier integrity. HUCB cells reduced the amount of TNF-α and IFN-γ released by activated primary rat splenocytes, which correlated with the expression of COX2 and IDO1.

The Future State of Newborn Stem Cell Banking.

Newborn stem cell banking began with the establishment of cord blood banks more than 25 years ago. Over the course of nearly three decades, there has been considerable evolution in the clinical application of stem cells isolated from newborn tissues. The industry now finds itself at an inflection point as personalized medicine and regenerative medicine continue to advance. In this review, we summarize our perspective on newborn stem cell banking in the context of the future potential that stem cells from perinatal tissues are likely to play in nascent applications. Specifically, we describe the relevance of newborn stem cell banking and how the cells stored can be utilized as starting material for the next generation of advanced cellular therapies and personalized medicine.

Quantitative analysis of composite umbilical cord tissue health using a standardized explant approach and an assay of metabolic activity.

BACKGROUND: Umbilical cord (UC) tissue can be collected in a noninvasive procedure and is enriched in progenitor cells with potential therapeutic value. Mesenchymal stromal cells (MSCs) can be reliably harvested from fresh or cryopreserved UC tissue by explant outgrowth with no apparent impact on functionality. A number of stem cell banks offer cryopreservation of UC tissue, alongside cord blood, for future cell-based applications. In this setting, measuring and monitoring UC quality is critical. MATERIALS AND METHODS: UC explants were evaluated using a plating and scoring system accounting for cell attachment and proliferation. Explant scores for fresh and cryopreserved-then-thawed tissue from the same UC were compared. Metabolic activity of composite UC tissue was also assayed after exposure of the tissue to conditions anticipated to affect UC quality and compared with explant scores within the same UC. RESULTS: All fresh and cryopreserved tissues yielded MSC-like cells, and cryopreservation of the tissue did not prevent the ability to isolate MSCs by the explant method. Thawed UC tissue scores were 91% (±0.6%; P = 0.0009) that of the fresh, biologically identical tissue. Within the same UC, explant scores correlated well to both cell yield (R2 = 0.85) and tissue metabolic activity (R2 = 0.69). DISCUSSION: A uniform explant scoring assay can provide information about the quality of composite UC tissue. Such quantitative measurement is useful for analysis of tissue variability and process monitoring. Additionally, a metabolic assay of UC tissue health provides results that correlate well to explant scoring results.

Expansion of Human Tregs from Cryopreserved Umbilical Cord Blood for GMP-Compliant Autologous Adoptive Cell Transfer Therapy.

Umbilical cord blood is a traditional and convenient source of cells for hematopoietic stem cell transplantation. Thymic regulatory T cells (Tregs) are also present in cord blood, and there is growing interest in the use of autologous Tregs to provide a low-risk, fully human leukocyte antigen (HLA)-matched cell product for treating autoimmune diseases, such as type 1 diabetes. Here, we describe a good manufacturing practice (GMP)-compatible Treg expansion protocol using fluorescence-activated cell sorting, resulting in a mean 2,092-fold expansion of Tregs over a 16-day culture for a median yield of 1.26 × 109 Tregs from single-donor cryopreserved units. The resulting Tregs passed prior clinical trial release criteria for Treg purity and sterility, including additional rigorous assessments of FOXP3 and Helios expression and epigenetic analysis of the FOXP3 Treg-specific demethylated region (TSDR). Compared with expanded adult peripheral blood Tregs, expanded cord blood Tregs remained more naive, as assessed by continued expression of CD45RA, produced reduced IFN-γ following activation, and effectively inhibited responder T cell proliferation. Immunosequencing of the T cell receptor revealed a remarkably diverse receptor repertoire within cord blood Tregs that was maintained following in vitro expansion. These data support the feasibility of generating GMP-compliant Tregs from cord blood for adoptive cell transfer therapies and highlight potential advantages in terms of safety, phenotypic stability, autoantigen specificity, and tissue distribution.

Knowledge of HIV seropositivity is a predictor for initiation of illicit drug use: incidence of drug use initiation among female sex workers in a high HIV-prevalence area of China.

BACKGROUND: Drug use and sex work have had facilitative roles in the transmission of HIV/AIDS in China. Stopping drug use among sex workers may help to control the growth of the HIV/AIDS epidemic among Chinese sex workers. METHODS: From March 2006 to November 2009, female sex workers (FSW) in Kaiyuan City, Yunnan, China were recruited into an open cohort study. Participants were interviewed and tested for drug use and HIV/sexually transmitted infection (STI) prevalence. Follow-up surveys were conducted every six months. Multivariate Cox proportional hazards regression model with time dependent variables was used to measure the associations between independent variables and drug initiation. RESULTS: During the course of the study, 66 (8.8%) FSWs initiated drug use yielding an overall incidence of 6.0 per 100 person years (PY) (95% confidence interval [CI], 4.67-7.58). In the multivariate Cox proportional hazards regression model, being HIV-positive and aware of positive serostatus (adjusted hazard ratio [AHR] 2.6, 95% CI 1.24-5.55), age at initiation of commercial sex work <20 years (AHR 1.8, 95% CI 1.12-3.01), and working in a high-risk establishment (AHR 1.9, 95% CI 1.14-3.04) were associated with illicit drug initiation. CONCLUSIONS: Being HIV-positive and aware of positive serostatus was the most salient predictor for the initiation of illicit drug use. Interventions offering sources of education, treatment, support, and counseling to HIV-positive FSWs need to be implemented in order to help promote self-efficacy and safe behaviors among this group of high-risk women.

Xenopus tropicalis egg extracts provide insight into scaling of the mitotic spindle.

The African clawed frog Xenopus laevis has been instrumental to investigations of both development and cell biology, but the utility of this model organism for genetic and proteomic studies is limited by its long generation time and unsequenced pseudotetraploid genome. Xenopus tropicalis, which is a small, faster-breeding relative of X. laevis, has recently been adopted for research in developmental genetics and functional genomics, and has been chosen for genome sequencing. We show that X. tropicalis egg extracts reconstitute the fundamental cell cycle events of nuclear formation and bipolar spindle assembly around exogenously added sperm nuclei. Interestingly, X. tropicalis spindles were approximately 30% shorter than X. laevis spindles, and mixing experiments revealed a dynamic, dose-dependent regulation of spindle size by cytoplasmic factors. Measurements of microtubule dynamics revealed that microtubules polymerized slower in X. tropicalis extracts compared to X. laevis, but that this difference is unlikely to account for differences in spindle size. Thus, in addition to expanding the range of developmental and cell biological experiments, the use of X. tropicalis provides novel insight into the complex mechanisms that govern spindle morphogenesis.