A novel therapeutic management for diabetes patients with chronic limb-threatening ischemia: comparison of autologous bone marrow mononuclear cells versus allogenic Wharton jelly-derived mesenchymal stem cells.

BACKGROUND: Chronic limb-threatening ischemia (CLTI) represents the final stage of peripheral arterial disease. Approximately one-third of patients with CLTI are not eligible for conventional surgical treatments. Furthermore, patients with advanced stage of CLTI are prone to amputation and death. Thus, an effective therapeutic strategy is urgently needed. In this context, autologous bone marrow mononuclear cell (auto-BM-MNC) and allogeneic mesenchymal stem cells represent a promising therapeutic approach for treating CLTI. In this study, we compared the safety and beneficial therapeutic effect of auto-BM-MNC versus allogeneic Wharton jelly-derived mesenchymal stem cells (allo-WJ-MSCs) in diabetic patients with CLTI. METHODS: We performed a randomized, prospective, double-blind and controlled pilot study. Twenty-four diabetic patients in the advanced stage of CLTI (4 or 5 in Rutherford's classification) and a transcutaneous oxygen pressure (TcPO2) below 30 mmHg were randomized to receive 15 injections of (i) auto-BM-MNC (7.197 × 106 ± 2.984 × 106 cells/mL) (n = 7), (ii) allo-WJ-MSCs (1.333 × 106 cells/mL) (n = 7) or (iii) placebo solution (1 mL) (n = 10), which were administered into the periadventitial layer of the arterial walls under eco-Doppler guidance. The follow-up visits were at months 1, 3, 6, and 12 to evaluate the following parameters: (i) Rutherford's classification, (ii) TcPO2, (iii) percentage of wound closure, (iv) pain, (v) pain-free walking distance, (vi) revascularization and limb-survival proportion, and (vii) life quality (EQ-5D questionnaire). RESULTS: No adverse events were reported. Patients with CLTI who received auto-BM-MNC and allo-WJ-MSCs presented an improvement in Rutherford's classification, a significant increase in TcPO2 values‬, a reduction in the lesion size in a shorter time, a decrease in the pain score and an increase in the pain-free walking distance, in comparison with the placebo group. In addition, the participants treated with auto-BM-MNC and allo-WJ-MSCs kept their limbs during the follow-up period, unlike the placebo group, which had a marked increase in amputation. CONCLUSIONS: Our results showed that patients with CLTI treated with auto-BM-MNC and allo-WJ-MSCs conserved 100% of their limb during 12 months of the follow-up compared to the placebo group, where 60% of participants underwent limb amputation in different times. Furthermore, we observed a faster improvement in the allo-WJ-MSC group, unlike the auto-BM-MNC group. Trial registration This study was retrospectively registered at ClinicalTrials.gov (NCT05631444).

Role of mesenchymal stromal cells derivatives in diabetic foot ulcers: a controlled randomized phase 1/2 clinical trial.

BACKGROUND: Diabetes-related foot complications have been identified as the most common isolated cause of morbidity among patients with diabetes and the leading cause of amputation. Therefore, new strategies to stimulate skin regeneration may provide a novel therapeutic approach to reduce non-healing ulcer disease. Recently, we demonstrated in proof-of-concept in humans that administration of allogeneic bone marrow mesenchymal stromal cellss derivatives (allo-hBM-MSCDs) is effective in a similar way to the use of allogeneic bone marrow mesenchymal stromal cellss (allo-hBM-MSCs) in grade 2 diabetic foot ulcers (DFUs). AIM: To assess the safety and efficacy profile of the allo-hBM-MSCDs relative to the conventional approach (PolyMen® dressing) in 1/2 clinical trial phases in patients with grade 1 and 2 DFUs. METHODS: In the present study, we used 2 doses of allo-hBM-MSCDs (1 mL) or 1 dose of allo-hBM-MSCs (1 × 106 cells) intradermally injected around wounds and assessed their safety and effectiveness, relative to the conventional approach (PolyMem dressing). Allo-hBM-MSCDs and allo-hBM-MSCs were produced in a certified Good Manufacturing Practice-type Laboratory. Patients with grade 1 and 2 DFUs were randomized to receive allo-hBM-MSCDs (n=12), allo-hBM-MSCs (n=6) or conventional treatment (PolyMem dressing) (n=10). The wound-healing process was macroscopically evaluated until the complete closure of the ulcers. RESULTS: No adverse events were reported. Patients with grade 1 and 2 DFUs treated with either allo-hBM-MSCDs or allo-hBM-MSCs, achieved greater percentages of wound closure, enhanced skin regeneration in shorter times and a greater ulcer-free survival relative to the patients who received conventional treatment. Finally, through proteomic analysis, we elucidated the proteins and growth factors that are secreted by allo-hBM-MSCs and relevant to the wound-healing process. In addition, by combining proteomics with Gene Ontology analysis, we comprehensively classified secreted proteins on both biological process and molecular function. CONCLUSIONS: In this phase 1/2 trial, our cumulative results suggest that 2 doses of allo-hBM-MSCDs combined with a wound dressing are a safe and effective treatment for grade 1 and 2 DFUs.

Current Advances in the Development of Hydrogel-Based Wound Dressings for Diabetic Foot Ulcer Treatment.

Diabetic foot ulcers (DFUs) are one of the most prevalent complications associated with diabetes mellitus. DFUs are chronic injuries that often lead to non-traumatic lower extremity amputations, due to persistent infection and other ulcer-related side effects. Moreover, these complications represent a significant economic burden for the healthcare system, as expensive medical interventions are required. In addition to this, the clinical treatments that are currently available have only proven moderately effective, evidencing a great need to develop novel strategies for the improved treatment of DFUs. Hydrogels are three-dimensional systems that can be fabricated from natural and/or synthetic polymers. Due to their unique versatility, tunability, and hydrophilic properties, these materials have been extensively studied for different types of biomedical applications, including drug delivery and tissue engineering applications. Therefore, this review paper addresses the most recent advances in hydrogel wound dressings for effective DFU treatment, providing an overview of current perspectives and challenges in this research field.

Decellularized Tissues for Wound Healing: Towards Closing the Gap Between Scaffold Design and Effective Extracellular Matrix Remodeling.

The absence or damage of a tissue is the main cause of most acute or chronic diseases and are one of the appealing challenges that novel therapeutic alternatives have, in order to recover lost functions through tissue regeneration. Chronic cutaneous lesions are the most frequent cause of wounds, being a massive area of regenerative medicine and tissue engineering to have efforts to develop new bioactive medical products that not only allow an appropriate and rapid healing, but also avoid severe complications such as bacterial infections. In tissue repair and regeneration processes, there are several overlapping stages that involve the synergy of cells, the extracellular matrix (ECM) and biomolecules, which coordinate processes of ECM remodeling as well as cell proliferation and differentiation. Although these three components play a crucial role in the wound healing process, the ECM has the function of acting as a biological platform to permit the correct interaction between them. In particular, ECM is a mixture of crosslinked proteins that contain bioactive domains that cells recognize in order to promote migration, proliferation and differentiation. Currently, tissue engineering has employed several synthetic polymers to design bioactive scaffolds to mimic the native ECM, by combining biopolymers with growth factors including collagen and fibrinogen. Among these, decellularized tissues have been proposed as an alternative for reconstructing cutaneous lesions since they maintain the complex protein conformation, providing the required functional domains for cell differentiation. In this review, we present an in-depth discussion of different natural matrixes recently employed for designing novel therapeutic alternatives for treating cutaneous injuries, and overview some future perspectives in this area.

Effect of biomolecules derived from human platelet-rich plasma on the ex vivo expansion of human adipose-derived mesenchymal stem cells for clinical applications.

Mesenchymal stem cells are a tool in cell therapies but demand a large cell number per treatment, for that, suitable culture media is required which contains fetal bovine serum (FBS). However, for cell-based therapy applications, the use of FBS is problematic. Several alternatives to FBS have been explored, including human derivatives from platelet-rich plasma (hD-PRP). Although various studies have evaluated the impact of hD-PRP on MSC proliferation and differentiation, few of them have assessed their influence on processes, such as metabolism and gene expression. Here, we cultured human adipose-derived MSCs (hAD-MSCs) in media supplemented with either 10% hD-PRP (hD-PRP-SM) or 10% FBS (FBS-SM) in order to characterize them and evaluate the effect of hD-PRP on cell metabolism, gene expression of associated regenerative factors, as well as chromosome stability during cell expansion. We found that hAD-MSCs cultured in hD-PRP-SM have a greater cell elongation but express similar surface markers; in addition, hD-PRP-SM promoted a significant osteogenic differentiation in the absence of differentiation medium and increased the growth rate, maintaining chromosomal stability. In terms of cell metabolic profile, hAD-MSC behavior did not reveal any differences between both culture conditions. Conversely, significant differences in collagen I and angiopoietin 2 expression were observed between both conditions. The present results suggest that hD-PRP may influence hAD-MSC behavior.

Identifying new potential genetic biomarkers for HELLP syndrome using massive parallel sequencing.

BACKGROUND: Preeclampsia (PE) is a frequently occurring multisystemic disease affecting ~5% of pregnancies. PE patients may develop HELLP syndrome (haemolysis, elevated liver enzymes, and low platelet), a mother and foetus life-threatening condition. Research into HELLP's genetic origin has been relatively unsuccessful, mainly because normal placental function and blood pressure regulation involve the fine-regulation of hundreds of genes. OBJECTIVE: To identify new genes and mutations constituting potential biomarkers for HELLP syndrome. STUDY DESIGN: The present case-control study involved whole-exome sequencing of 79 unrelated HELLP women. Candidate variants were screened in a control population constituted by 176 individuals. Stringent bioinformatics filters were used for selecting potentially etiological sequence variants in a subset of 487 genes. We used robust in silico mutation modelling for predicting the potential effect on protein structure. RESULTS: We identified numerous sequence variants in genes related to angiogenesis/coagulation/blood pressure regulation, cell differentiation/communication/adhesion, cell cycle and transcriptional gene regulation, extracellular matrix biology, lipid metabolism and immunological response. Five sequence variants generated premature stop codons in genes playing an essential role in placental physiology (STOX1, PDGFD, IGF2, MMP1 and DNAH11). Six variants (ERAP1- p.Ile915Thr, ERAP2- p.Leu837Ser, COMT-p.His192Gln, CSAD-p.Pro418Ser, CDH1- p.Ala298Thr and CCR2-p.Met249Lys) led to destabilisation of protein structure as they had significant energy and residue interaction-related changes. We identified at least two mutations in 57% of patients, arguing in favour of a polygenic origin for the HELLP syndrome. CONCLUSION: Our results provide novel evidence regarding PE/HELLP's genetic origin, leading to new biomarkers, having potential clinical usefulness, being proposed.

Mesenchymal stem cells derivatives as a novel and potential therapeutic approach to treat diabetic foot ulcers.

SUMMARY: Diabetic foot ulcer morbidity and mortality are dramatically increasing worldwide, reinforcing the urgency to propose more effective interventions to treat such a devastating condition. Previously, using a diabetic mouse model, we demonstrated that administration of bone marrow mesenchymal stem cells derivatives is more effective than the use of bone marrow mesenchymal stem cells alone. Here, we used the aforementioned treatments on three patients with grade 2 diabetic foot ulcers and assessed their beneficial effects, relative to the conventional approach. In the present study, two doses of cell derivatives, one dose of mesenchymal stem cells or one dose of vehicle (saline solution with 5% of human albumin), were intradermally injected around wounds. Wound healing process and changes on re-epithelialization were macroscopically evaluated until complete closure of the ulcers. All ulcers were simultaneously treated with conventional treatment (PolyMen® dressing). Patients treated with either cell derivatives or mesenchymal stem cells achieved higher percentages of wound closure in shorter times, relative to the patient treated with the conventional treatment. The cell derivative and mesenchymal stem cells approaches resulted in complete wound closure and enhanced skin regeneration at some point between days 35 and 42, although no differences between these two treatments were observed. Moreover, wounds treated with the conventional treatment healed after 161 days. Intradermal administration of cell derivatives improved wound healing to a similar extent as mesenchymal stem cells. Thus, our results suggest that mesenchymal stem cell derivatives may serve as a novel and potential therapeutic approach to treat diabetic foot ulcers. LEARNING POINTS: In diabetic mouse models, the administration of mesenchymal stem cells derivatives have been demonstrated to be more effective than the use of marrow mesenchymal stem cells alone. Mesenchymal stem cells have been explored as an attractive therapeutic option to treat non-healing ulcers. Mesenchymal stem cells derivatives accelerate the re-epithelialization on diabetic foot ulcers.

C-reactive protein, interleukin-6 and pre-eclampsia: large-scale evidence from the GenPE case-control study.

Multiple small studies have suggested that women with pre-eclampsia present elevated levels of C-reactive protein (CRP) and interleukin-6 (IL-6). However, little is known regarding the source of this CRP and IL-6 increase. Therefore, the aim of this study was to evaluate the relationship between CRP and IL-6 levels with pre-eclampsia considering different confounding factors. Using data from a large Colombian case-control study (3,590 cases of pre-eclampsia and 4,564 normotensive controls), CRP and IL-6 levels were measured in 914 cases and 1297 controls. The association between maternal serum levels of CRP and IL-6 with pre-eclampsia risk was evaluated using adjusted logistic regression models. Pre-eclampsia was defined as presence of blood pressure ≥140/90 mmHg and proteinuria ≥300mg/24 h (or ≥1 + dipstick). There was no evidence of association between high levels of CRP and IL-6 with pre-eclampsia after adjusting for the following factors: maternal and gestational age, ethnicity, place and year of recruitment, multiple-pregnancy, socio-economic position, smoking, and presence of infections during pregnancy. The adjusted OR for 1SD increase in log-CRP and log-IL-6 was 0.96 (95%CI 0.85, 1.08) and 1.09 (95%CI 0.97, 1.22), respectively. Although previous reports have suggested an association between high CRP and IL-6 levels with pre-eclampsia, sample size may lack the sufficient power to draw robust conclusions, and this association is likely to be explained by unaccounted biases. Our results, the largest case-control study reported up to date, demonstrate that there is not a causal association between elevated levels of CRP and IL-6 and the presence of pre-eclampsia.

Prognostic Value of MMP-9 -1562 C/T Gene Polymorphism in Patients With Sepsis.

INTRODUCTION: Matrix metalloproteinase-9 (MMP-9) plays an important role in the pathophysiology of sepsis. A single-nucleotide polymorphism (SNP) at position -1562 (C/T) in the MMP-9 gene has been associated with differential MMP-9 expression, being higher when the -1562 T allele is present. We evaluated the association of the SNP MMP9 -1562 C/T with severity and mortality in patients with sepsis to establish whether the prognosis of the disease is affected. MATERIALS AND METHODS: A case-control study exploratory was carried out in a cohort of infected patients. 540 individuals were selected in total, 270 patients with sepsis and 270 controls (infected but non-septic), classified according to the 2016 consensus (Sepsis-3). The presence of the single-nucleotide polymorphism (SNP; allele T and/or allele C) was determined through analyses of restriction fragment length polymorphism and plasma levels of MMP-9 were determined through enzyme-linked immunosorbent assay immunoassay. RESULTS: SNP MMP-9 -1562 has two known alleles (T and C), with predominance of the C over the T allele; in the group of patients with sepsis, T allele was found in 7.2% of cases, while C allele in the rest (92.8%); in comparison, in the group of infected but non-septic patients, frequencies were 9.4% for T allele and 90.6% for the C allele (P = .33). Also, the presence of the polymorphic T allele was not related to the levels of MMP-9 in patients with sepsis in comparison with infected but non-septic patients 780 (397-1375) ng/mL vs 646 (172-1249) ng/mL (P = .64). There was also no association between the SNP and sepsis mortality (P = .78). CONCLUSIONS: We concluded that there was no association between the SNP MMP9 -1562 C/T and sepsis or between the SNP MMP9 -1562 C/T and sepsis mortality in the Northeastern Colombian septic patient cohort. Further research is needed to clarify the correlation among sepsis, genetic factors with allele T and MMP-9 plasma concentration.

Association of pre-eclampsia risk with maternal levels of folate, homocysteine and vitamin B12 in Colombia: A case-control study.

BACKGROUND: Maternal serum concentrations of folate, homocysteine, and vitamin B12 have been associated with pre-eclampsia. Nevertheless, reported studies involve limited number of cases to reliably assess the nature of these associations. Our aim was to examine the relation of these three biomarkers with pre-eclampsia risk in a large Colombian population. MATERIALS AND METHODS: Design: A case-control study. Setting: Cases of pre-eclampsia and healthy pregnant controls were recruited at the time of delivery from eight different Colombian cities between 2000 and 2012. Population or Sample: 2978 cases and 4096 controls were studied. Maternal serum concentrations of folate, homocysteine, and vitamin B12 were determined in 1148 (43.6%) cases and 1300 (31.7%) controls. Also, self-reported folic acid supplementation was recorded for 2563 (84%) cases and 3155 (84%) controls. Analysis: Adjusted odds ratios (OR) for pre-eclampsia were estimated for one standard deviation (1SD) increase in log-transformed biomarkers. Furthermore, we conducted analyses to compare women that reported taking folic acid supplementation for different periods during pregnancy. Main Outcomes Measures: Odds ratio for pre-eclampsia. RESULTS: After adjusting for potential confounders in logistic regression models, the OR for pre-eclampsia was 0.80 (95% CI: 0.72, 0.90) for 1SD increase in log-folate, 1.16 (95%CI: 1.05, 1.27) for 1SD increase in log-homocysteine, and 1.10 (95%CI: 0.99, 1.22) for 1SD increase in log-vitamin B12. No interactions among the biomarkers were identified. Women who self-reported consumption of folic acid (1 mg/day) throughout their pregnancy had an adjusted OR for pre-eclampsia of 0.86 (95%CI: 0.67, 1.09) compared to women that reported no consumption of folic acid at any point during pregnancy. CONCLUSIONS: Maternal serum concentrations of folate were associated as a protective factor for pre-eclampsia while concentrations of homocysteine were associated as a risk factor. No association between maternal vitamin B12 concentrations and preeclampsia was found.

Percepción de diversos sectores sociales de Colombia sobre los biobancos con fines de investigación / The perception of different social agents in Colombia regarding biobanks for research purposes

Introducción. Los biobancos con fines de investigación son un bien público que necesita de la participación activa de todas las partes interesadas, por lo cual es importante conocer la percepción que tiene el público general en Colombia sobre su intervención en un biobanco. Objetivo. Indagar en diferentes sectores sociales colombianos sobre su percepción en torno a la donación de material biológico humano para ser almacenado en biobancos con fines de investigación. Materiales y métodos. Se hizo un estudio exploratorio tanto cuantitativo como cualitativo, entre personas sanas de diferentes sectores del país mediante una encuesta anónima sobre su conocimiento y actitudes con respecto a los biobancos. Resultado. La encuesta fue respondida por 368 personas, que incluían investigadores en salud, abogados y miembros de comités de ética de la investigación. El 96 % de los sujetos expresó su voluntad de donar material biológico, aunque el 60 % manifestó tener desconfianza en que sus muestras fueran usadas en algunos tipos de investigación, especialmente en clonación humana. Cerca de la mitad de los participantes refirieron saber qué era un biobanco, sin embargo, menos del 3 % tenía claridad suficiente sobre el concepto. Conclusión. Los participantes expresaron su disposición a donar y almacenar material biológico con fines de investigación, así como su opinión sobre algunos aspectos de la gestión de los biobancos. Las opiniones del público general se deben tener en cuenta en el desarrollo de políticas que regulen la actividad de los biobancos con fines de investigación en Colombia.

Introduction: Biobanks for research purposes are public assets that require active participation from all interested parties; therefore, it is important to discern and investigate the perception that the general public in Colombia has with regards to their participation in a biobank. Objective: To question different healthy Colombian social agents about the perception they have on donating human biological material to be stored in a biobank for future research purposes. Materials and methods: We conducted an exploratory quantitative and qualitative research by means of an anonymous survey on healthy members of the Colombian community in order to evaluate their knowledge and stances related to biobanks. Results: Three hundred sixty-eight (368) individuals completed the survey, including health-care researchers, lawyers and members of research ethics committees. Ninety-six percent (96%) of the subjects stated their willingness to donate biological material to biobanks, although 60% expressed distress about their samples being used for certain research activities, mainly human cloning. Even though about half of the participants reported knowing what a biobank is, less than 3% of the individuals had a clear concept of them. Conclusion: Participants showed their willingness to donate and store their biological material for research purposes. Similarly, they expressed their opinion about issues related to the management of biobanks. It is necessary to take into account the opinions of the general public in the development of policies that regulate biobanks for research purposes in Colombia.

Lipid profile, plasma apolipoproteins, and pre-eclampsia risk in the GenPE case-control study.

BACKGROUND AND AIMS: Pre-eclampsia constitutes a leading cause of maternal and perinatal morbidity and mortality. Pre-eclampsia susceptibility is believed to be associated with altered lipid profiles and abnormal lipid metabolism via lipid peroxidation that leads to endothelial dysfunction. The goal of this study was to evaluate the association of maternal blood lipid and apolipoprotein levels with pre-eclampsia in a large-scale study. METHODS: Using data from a large case-control study (1366 cases of pre-eclampsia and 1741 normotensive controls), the association between the distributions of eight lipid fractions and pre-eclampsia risk was evaluated using adjusted logistic regression models. Pre-eclampsia was defined as blood pressure ≥140/90 mmHg and proteinuria ≥300 mg/24 h (>1 + dipstick). Sub-group analyses were conducted for early (<34 weeks) and late (≥37 weeks) pre-eclampsia, estimating the effect of 1 standard deviation increase in log-transformed lipid fraction levels in adjusted multinomial regression models. RESULTS: After adjustment for potential confounders, concentrations of triglycerides, apolipoprotein E (ApoE) and the relationship between apolipoprotein B and A1 (ApoB/ApoA1) showed the strongest associations with pre-eclampsia, particularly for those cases with an early onset. CONCLUSIONS: Higher levels of triglycerides, ApoE and the ApoB/ApoA1 ratio are associated with an increased risk of pre-eclampsia. Further studies that allow for a causal inference are needed to confirm or refute the aetiological role of blood lipids in pre-eclampsia.

Influence of collagen-based integrin α1 and α2 mediated signaling on human mesenchymal stem cell osteogenesis in three dimensional contexts.

Collagen I interactions with integrins α1 and α2 are known to support human mesenchymal stem cell (hMSC) osteogenesis. Nonetheless, elucidating the relative impact of specific integrin interactions has proven challenging, in part due to the complexity of native collagen. In the present work, we employed two collagen-mimetic proteins-Scl2-2 and Scl2-3- to compare the osteogenic effects of integrin α1 versus α2 signaling. Scl2-2 and Scl2-3 were both derived from Scl2-1, a triple helical protein lacking known cell adhesion, cytokine binding, and matrix metalloproteinase sites. However, Scl2-2 and Scl2-3 were each engineered to display distinct collagen-based cell adhesion motifs: GFPGER (binding integrins α1 and α2 ) or GFPGEN (binding only integrin α1 ), respectively. hMSCs were cultured within poly(ethylene glycol) (PEG) hydrogels containing either Scl2-2 or Scl2-3 for 2 weeks. PEG-Scl2-2 gels were associated with increased hMSC osterix expression, osteopontin production, and calcium deposition relative to PEG-Scl2-3 gels. These data indicate that integrin α2 signaling may have an increased osteogenic effect relative to integrin α1 . Since p38 is activated by integrin α2 but not by integrin α1 , hMSCs were further cultured in PEG-Scl2-2 hydrogels in the presence of a p38 inhibitor. Results suggest that p38 activity may play a key role in collagen-supported hMSC osteogenesis. This knowledge can be used toward the rational design of scaffolds which intrinsically promote hMSC osteogenesis. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2594-2604, 2018.

Vitamin D deficiency and pre-eclampsia in Colombia: PREVitD study.

PURPOSE: Pre-eclampsia is a multisystem disorder characterized by new-onset hypertension and proteinuria during pregnancy. Pre-eclampsia remains a major cause of maternal death in low-income countries. Vitamin D has a very diverse biological role in cardiovascular diseases. This study will evaluate the association of vitamin D levels and relevance to pre-eclampsia. METHODS: We conducted a case-control study of women recruited from the GenPE (Genetics and Pre-eclampsia) Colombian registry. This is a multicenter case-control study conducted in eight Colombian cities. 25-Hydroxyvitamin D (25(OH)D) concentration was measured using liquid-chromatography-tandem mass spectrometry from 1013 women with pre-eclampsia and 1015 mothers without pre-eclampsia (controls). RESULTS: Fifty-two percent of women with pre-eclampsia were vitamin D deficient. The 25(OH)D concentrations were significantly lower in the pre-eclampsia (mean 29.99 ng/mL; 95% CI: 29.40-30.58 ng/mL) group compared to controls (mean 33.7 ng/mL; 95% CI: 33.20-34.30 ng/mL). In the unadjusted model, maternal vitamin D deficiency, defined by maternal 25(OH)D concentration <30 ng/mL, was associated with an increased probability of suffering from pre-eclampsia (OR 2.10; 95% CI, 1.75-2.51). After adjusting for covariates, a similarly increased probability of having pre-eclampsia was observed (OR 2.18; 95% CI, 1.80-2.64) among women with vitamin D deficiency, relative to controls. CONCLUSION: Although the results suggest that low maternal concentrations of 25(OH)D increase pre-eclampsia risk, this evidence may not be indicative of a causal association. Future studies are needed to confirm a definite causal relationship between concentrations of vitamin D and the risk of pre-eclampsia, by means of powered clinical trials.

The perception of different social agents in Colombia regarding biobanks for research purposes / Percepción de diversos sectores sociales de Colombia sobre los biobancos con fines de investigación

Introduction: Biobanks for research purposes are public assets that require active participation from all interested parties; therefore, it is important to discern and investigate the perception that the general public in Colombia has with regards to their participation in a biobank. Objective: To question different healthy Colombian social agents about the perception they have on donating human biological material to be stored in a biobank for future research purposes. Materials and methods: We conducted an exploratory quantitative and qualitative research by means of an anonymous survey on healthy members of the Colombian community in order to evaluate their knowledge and stances related to biobanks. Results: Three hundred sixty-eight (368) individuals completed the survey, including health-care researchers, lawyers and members of research ethics committees. Ninety-six percent (96%) of the subjects stated their willingness to donate biological material to biobanks, although 60% expressed distress about their samples being used for certain research activities, mainly human cloning. Even though about half of the participants reported knowing what a biobank is, less than 3% of the individuals had a clear concept of them. Conclusion: Participants showed their willingness to donate and store their biological material for research purposes. Similarly, they expressed their opinion about issues related to the management of biobanks. It is necessary to take into account the opinions of the general public in the development of policies that regulate biobanks for research purposes in Colombia.

Introducción. Los biobancos con fines de investigación son un bien público que necesita de la participación activa de todas las partes interesadas, por lo cual es importante conocer la percepción que tiene el público general en Colombia sobre su intervención en un biobanco.Objetivo. Indagar en diferentes sectores sociales colombianos sobre su percepción en torno a la donación de material biológico humano para ser almacenado en biobancos con fines de investigación.Materiales y métodos. Se hizo un estudio exploratorio tanto cuantitativo como cualitativo, entre personas sanas de diferentes sectores del país mediante una encuesta anónima sobre su conocimiento y actitudes con respecto a los biobancos.Resultado. La encuesta fue respondida por 368 personas, que incluían investigadores en salud, abogados y miembros de comités de ética de la investigación. El 96 % de los sujetos expresó su voluntad de donar material biológico, aunque el 60 % manifestó tener desconfianza en que sus muestras fueran usadas en algunos tipos de investigación, especialmente en clonación humana. Cerca de la mitad de los participantes refirieron saber qué era un biobanco, sin embargo, menos del 3 % tenía claridad suficiente sobre el concepto.Conclusión. Los participantes expresaron su disposición a donar y almacenar material biológico con fines de investigación, así como su opinión sobre algunos aspectos de la gestión de los biobancos. Las opiniones del público general se deben tener en cuenta en el desarrollo de políticas que regulen la actividad de los biobancos con fines de investigación en Colombia.

The role of bone marrow mesenchymal stromal cell derivatives in skin wound healing in diabetic mice.

Mesenchymal stromal cells (MSCs) have shown to be a promising tool in cell therapies to treat different conditions. Several pre-clinical and clinical studies have proved that the transplantation of MSCs improves wound healing. Here, we compare the beneficial effects of mouse bone marrow-derived allogeneic MSCs (allo-mBM-MSCs) and their acelullar derivatives (allo-acd-mMSCs) on skin wound healing in Non-Obese Diabetic (NOD) mice. One dose of allo-mBM-MSCs (1×106 cells) or one dose of allo-acd-mMSCs (1X) were intradermally injected around wounds in 8-10 week old female NOD mice. Wound healing was evaluated macroscopically (wound closure) every two days, and microscopically (reepithelialization, dermoepidermal junction, skin appendage regeneration, leukocyte infiltration, vascularization, granulation tissue formation, and density of collagen fibers in the dermis) after 16 days of MSC injection. In addition, we measured growth factors and specific proteins that were present in the allo-acd-mMSCs. Results showed significant differences in the wound healing kinetics of lesions that received allo-acd-mMSCs compared to lesions that received vehicle or allo-mBM-MSCs. In particular, mice treated with allo-acd-mMSCs reached significantly higher percentages of wound closure at day 4, 6 and 8, relative to the allo-mBM-MSCs and vehicle groups (p < 0.05), while wound closure percentages could not be statistically distinguished between the allo-mBM-MSCs and vehicle groups. Also, allo-acd-mMSCs had a greater influence in the skin would healing process. Specifically, they caused a less pronounced inflammatory severe response (p < 0.0001), more granulation tissue formation at an advanced stage (p < 0.0001), and higher density of collagen fibers (p < 0.05) compared to the other groups. Nevertheless, at day 16, both allo-mBM-MSCs and allo-acd-mMSCs revealed a higher effect on the recovery of the quality skin (continuous epidermis; regular dermoepidermal junction and skin appendages) relative to untreated lesions (p < 0.0001), but not between them. On the other hand, ELISA analyses indicated that the allo-acd-mMSCs contained growth factors and proteins relevant to wound healing such as IGF-1, KGF, HGF, VEGF, ANG-2, MMP-1, CoL-1 and PGE2. Compared to allo-acd-mMSCs, the administration of allo-mBM-MSCs is insufficient for wound healing in diabetic mice and delays the therapeutic effect, which maybe explained by the fact that trophic factors secreted by MSCs are critical for skin regeneration, and not the cells per se, suggesting that MSCs may require some time to secrete these factors after their administration.

Evaluation of late outgrowth endothelial progenitor cell and umbilical vein endothelial cell responses to thromboresistant collagen-mimetic hydrogels.

Bioactive coatings which support the adhesion of late-outgrowth peripheral blood endothelial progenitor cells (EOCs) are actively being investigated as a means to promote rapid endothelialization of "off-the-shelf," small-caliber arterial graft prostheses following implantation. In the present work, we evaluated the behavior of EOCs on thromboresistant graft coatings based on the collagen-mimetic protein Scl2-2 and poly(ethylene glycol) (PEG) diacrylate. Specifically, the attachment, proliferation, migration, and phenotype of EOCs on PEG-Scl2-2 hydrogels were evaluated as a function of Scl2-2 concentration (4, 8, and 12 mg/mL) relative to human umbilical vein endothelial cells (HUVECs). Results demonstrate the ability of each PEG-Scl2-2 hydrogel formulation to support EOC and HUVEC adhesion, proliferation, and spreading. However, only the 8 and 12 mg/mL PEG-Scl2-2 hydrogels were able to support stable EOC and HUVEC confluence. These PEG-Scl2-2 formulations were, therefore, selected for evaluation of their impact on EOC and HUVEC phenotype relative to PEG-collagen hydrogels. Cumulatively, both gene and protein level data indicated that 8 mg/mL PEG-Scl2-2 hydrogels supported similar or improved levels of EOC maturation relative to PEG-collagen controls based on evaluation of CD34, VEGFR2, PECAM-1, and VE-Cadherin. The 8 mg/mL PEG-Scl2-2 hydrogels also appeared to support similar or improved levels of EOC homeostatic marker expression relative to PEG-collagen hydrogels based on von Willebrand factor, collagen IV, NOS3, thrombomodulin, and E-selectin assessment. Combined, the present results indicate that PEG-Scl2-2 hydrogels warrant further investigation as "off-the-shelf" graft coatings. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1712-1724, 2017.

Cell layer-electrospun mesh composites for coronary artery bypass grafts.

This work investigates the potential of cell layer-electrospun mesh constructs as coronary artery bypass grafts. These cell-mesh constructs were generated by first culturing a confluent layer of 10T½ smooth muscle progenitor cells on a high strength electrospun mesh with uniaxially aligned fibers. Cell-laden mesh sheets were then wrapped around a cylindrical mandrel such that the mesh fibers were aligned circumferentially. The resulting multi-layered constructs were then cultured for 4 wks in media supplemented with TGF-ß1 and ascorbic acid to support 10T½ differentiation toward a smooth muscle cell-like fate as well as to support elastin and collagen production. The underlying hypothesis of this work was that extracellular matrix (ECM) deposited by the cell layers would act as an adhesive agent between the individual mesh layers, providing strength to the construct as well as a source for structural elasticity at low strains. In addition, the structural anisotropy of the mesh would inherently guide desired circumferential cell and ECM alignment. Results demonstrate that the cell-mesh constructs exhibited a J-shaped circumferential stress-strain response similar to that of native coronary artery, while also displaying acceptable tensile strength. Furthermore, associated 10T½ cells and deposited collagen fibers showed a high degree of circumferential alignment. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2200-2209, 2016.

Collagen-mimetic hydrogels promote human endothelial cell adhesion, migration and phenotypic maturation.

This work evaluates the response of human aortic endothelial cells (HAECs) to thromboresistant collagen-mimetic hydrogel coatings toward improving the biocompatibility of existing "off-the-shelf" small-caliber vascular grafts. Specifically, bioactive hydrogels - previously shown to support α1/α2 integrin-mediated cell adhesion but to resist platelet activation - were fabricated by combining poly(ethylene glycol) (PEG) with a 120 kDa, triple-helical collagen-mimetic protein(Scl2-2) containing the GFPGER adhesion sequence. Analysis of HAECs seeded onto the resulting PEG-Scl2-2 hydrogels demonstrated that HAEC adhesion increased with increasing Scl2-2 concentration, while HAEC migration rate decreased over this same concentration range. In addition, evaluation of HAEC phenotype at confluence indicated significant differences in the gene expression of NOS3, thrombomodulin, and E-selectin on the PEG-Scl2-2 hydrogels relative to PEG-collagen controls. At the protein level, however, only NOS3 was significantly different between the PEG-Scl2-2 and PEG-collagen surfaces. Furthermore, PECAM-1 and VE-cadherin expression on PEG-Scl2-2 hydrogels versus PEG-collagen controls could not be distinguished at either the gene or protein level. Cumulatively, these data indicate the PEG-Scl2-2 hydrogels warrant further investigation as "off-the-shelf" graft coatings. In future studies, the Scl2-2 protein can potentially be modified to include additional extracellular matrix or cytokine binding sites to further improve endothelial cell responses.

Influence of select extracellular matrix proteins on mesenchymal stem cell osteogenic commitment in three-dimensional contexts.

Growth factors have been shown to be powerful mediators of mesenchymal stem cell (MSC) osteogenic differentiation. However, their use in tissue engineered scaffolds not only can be costly but also can induce undesired responses in surrounding tissues. Thus, the ability to specifically promote MSC osteogenic differentiation in the absence of exogenous growth factors via the manipulation of scaffold material properties would be beneficial. The current work examines the influence of select extracellular matrix (ECM) proteins on MSC osteogenesis toward the goal of developing scaffolds with intrinsically osteoinductive properties. Fibrinogen (FG), fibronectin (FN) and laminin-1 (LN) were chosen for evaluation due to their known roles in bone morphogenesis or bone fracture healing. These proteins were conjugated into poly(ethylene glycol) diacrylate (PEGDA) hydrogels and their effects on encapsulated 10T½ MSCs were evaluated. Specifically, following 1week of culture, mid-term markers of various MSC lineages were examined in order to assess the strength and specificity of the observed osteogenic responses. PEG-LN gels demonstrated increased levels of the osteogenic transcription factor osterix relative to day 0 levels. In addition, PEG-FG and PEG-LN gels were associated with increased deposition of bone ECM protein osteocalcin relative to PEG-FN gels and day 0. Importantly, the osteogenic response associated with FG and LN appeared to be specific in that markers for chondrocytic, smooth muscle cell and adipocytic lineages were not similarly elevated relative to day 0 in these gels. To gain insight into the integrin dynamics underlying the observed differentiation results, initial integrin adhesion and temporal alterations in cell integrin profiles were evaluated. The associated results suggest that α(2), α(v) and α(6) integrin subunits may play key roles in integrin-mediated osteogenesis.