Comparative Studies of Different Preservation Methods and Relative Freeze-Drying Formulations for Extracellular Vesicle Pharmaceutical Applications

Extracellular vesicles (EVs) have been studied for years for their role as effectors and mediators of cell-to-cell communication and their potential application to develop new and increasingly performing nanotechnological systems for the diagnosis and/or treatment of many diseases. Given all the EVs applications as just isolated, functionalized, or even engineered cellular-derived pharmaceuticals, the standardization of reliable and reproducible methods for their preservation is urgently needed. In this study, we isolated EVs from a healthy blood cell line, B lymphocytes, and compared the effectiveness of different storage methods and relative freeze-drying formulations to preserve some of the most important EVs’ key features, i.e., concentration, mean size, protein content, and surface antigen’s expression. To develop a preservation method that minimally affects the EVs’ integrity and functionality, we applied the freeze-drying process in combination with different excipients. Since EVs are isolated not only from body fluids but also from culture media conditioned by the cells growing there, we decided to test both the effects of the traditional pharmaceutical excipient and of biological media to develop EVs solidified products with desirable appearance and performance properties. Results showed that some of the tested excipients, i.e., sugars in combination with dextran and glycine, successfully maintained the stability and integrity of EVs upon lyophilization. In addition, to evaluate the preservation of the EVs’ biological activity, we assessed the cytotoxicity and internalization ability of the reconstituted EVs in healthy (B lymphocytes) and tumoral (Burkitt’s lymphoma) cells. Reconstituted EVs demonstrated toxicity only toward the cancerous cells, opening new therapeutic opportunities for the oncological field. Furthermore, our study showed how some biological or cellular-conditioned fluids, commonly used in the field of cell cultures, can act not only as cryoprotectants but also as active pharmaceutical ingredients, significantly tuning the therapeutic effect of EVs, even increasing their cellular internalization

How to monitor pregnancies complicated by fetal growth restriction and delivery below 32 weeks: a post-hoc sensitivity analysis of the TRUFFLE-study.

OBJECTIVES: In the recent TRUFFLE study it appeared that, in pregnancies complicated by fetal growth restriction (FGR) between 26 and 32 weeks, monitoring of the ductus venosus (DV) combined with computerised cardiotocography (cCTG) as a trigger for delivery, increased the chance of infant survival without neurological impairment. However, concerns in interpretation were raised as DV monitoring appeared associated with a non-significant increase in fetal death, and part of the infants were delivered after 32 weeks, after which the study protocol was no longer applied. This secondary sensitivity analysis focuses on women who delivered before 32 completed weeks, and analyses fetal death cases in detail. METHODS: We analysed the monitoring data of 317 women who delivered before 32 weeks, excluding women with absent infant outcome data or inevitable perinatal death. The association of the last monitoring data before delivery and infant outcome was assessed by multivariable analysis. RESULTS: The primary outcome (two year survival without neurological impairment) occurred more often in the two DV groups (both 83%) than in the CTG-STV group (77%), however the difference was not statistically significant (p = 0.21). Nevertheless, in surviving infants 93% was free of neurological impairment in the DV groups versus 85% in the CTG-STV group (p = 0.049). All fetal deaths (n = 7) occurred in women allocated to DV monitoring, which explains this difference. Assessment of the monitoring parameters that were obtained shortly before fetal death in these 7 cases showed an abnormal CTG in only one. Multivariable regression analysis of factors at study entry demonstrated that higher gestational age, larger estimated fetal weight 50th percentile ratio and lower U/C ratio were significantly associated with the (normal) primary outcome. Allocation to the DV groups had a smaller effect, but remained in the model (p < 0.1). Assessment of the last monitoring data before delivery showed that in the CTG-STV group abnormal fetal arterial Doppler was significantly associated with adverse outcome. In contrast, in the DV groups an abnormal DV was the only fetal monitoring parameter that was associated with adverse infant outcome, while fetal arterial Doppler, STV below CTG-group cut-off or recurrent fetal heart rate decelerations were not. CONCLUSIONS: In accordance with the results of the overall TRUFFLE study of the monitoring-intervention management of very early severe FGR we found that the difference in the proportion of infants surviving without neuroimpairment (the primary endpoint) was non-significant when comparing timing of delivery with or without changes in the DV waveform. However, the uneven distribution of fetal deaths towards the DV groups was likely by chance, and among surviving children neurological outcomes were better. Before 32 weeks, delaying delivery until abnormalities in DVPI or STV and/or recurrent decelerations occur, as defined by the study protocol, is therefore probably safe and possibly benefits long-term outcome

Longitudinal study of computerised cardiotocography in early fetal growth restriction.

OBJECTIVES: To explore if in early fetal growth restriction (FGR) the longitudinal pattern of short-term fetal heart rate (FHR) variation (STV) can be used for identifying imminent fetal distress and if abnormalities of FHR registration associate with two-year infant outcome. METHODS: The original TRUFFLE study assessed if in early FGR the use of ductus venosus Doppler pulsatility index (DVPI), in combination with a safety-net of very low STV and / or recurrent decelerations, could improve two-year infant survival without neurological impairment in comparison to computerised cardiotocography (cCTG) with STV calculation only. For this secondary analysis we selected women, who delivered before 32 weeks, and who had consecutive STV data for more than 3 days before delivery, and known infant two-year outcome data. Women who received corticosteroids within 3 days of delivery were excluded. Individual regression line algorithms of all STV values except the last one were calculated. Life table analysis and Cox regression analysis were used to calculate the day by day risk for a low STV or very low STV and / or FHR decelerations (DVPI group safety-net) and to assess which parameters were associated to this risk. Furthermore, it was assessed if STV pattern, lowest STV value or recurrent FHR decelerations were associated with two-year infant outcome. RESULTS: One hundred and fourty-nine women matched the inclusion criteria. Using the individual STV regression lines prediction of a last STV below the cCTG-group cut-off had a sensitivity of 0.42 and specificity of 0.91. For each day after inclusion the median risk for a low STV(cCTG criteria) was 4% (Interquartile range (IQR) 2% to 7%) and for a very low STV and / or recurrent decelerations (DVPI safety-net criteria) 5% (IQR 4 to 7%). Measures of STV pattern, fetal Doppler (arterial or venous), birthweight MoM or gestational age did not improve daily risk prediction usefully. There was no association of STV regression coefficients, a last low STV or /and recurrent decelerations with short or long term infant outcomes. CONCLUSION: The TRUFFLE study showed that a strategy of DVPI monitoring with a safety-net delivery indication of very low STV and / or recurrent decelerations could increase infant survival without neurological impairment at two years. This post-hoc analysis demonstrates that in early FGR the day by day risk of an abnormal cCTG as defined by the DVPI protocol safety-net criteria is 5%, and that prediction of this is not possible. This supports the rationale for cCTG monitoring more often than daily in these high-risk fetuses. Low STV and/or recurrent decelerations were not associated with adverse infant outcome and it appears safe to delay intervention until such abnormalities occur, as long as DVPI is in the normal range

Short-term effects of synchronized vs. non-synchronized NIPPV in preterm infants: study protocol for an unmasked randomized crossover trial

Abstract Background Non-invasive ventilation (NIV) has been recommended as the best respiratory support for preterm infants with respiratory distress syndrome (RDS). However, the best NIV technique to be used as first intention in RDS management has not yet been established. Nasal intermittent positive pressure ventilation (NIPPV) may be synchronized (SNIPPV) or non-synchronized to the infant’s breathing efforts. The aim of the study is to evaluate the short-term effects of SNIPPV vs. NIPPV on the cardiorespiratory events, trying to identify the best ventilation modality for preterm infants at their first approach to NIV ventilation support. Methods An unmasked randomized crossover study with three treatment phases was designed. All newborn infants < 32 weeks of gestational age with RDS needing NIV ventilation as first intention or after extubation will be consecutively enrolled in the study and randomized to the NIPPV or SNIPPV arm. After stabilization, enrolled patients will be alternatively ventilated with two different techniques for two time frames of 4 h each. NIPPV and SNIPPV will be administered with the same ventilator and the same interface, maintaining continuous assisted ventilation without patient discomfort. During the whole duration of the study, the patient’s cardiorespiratory data and data from the ventilator will be simultaneously recorded using a polygraph connected to a computer. The primary outcome is the frequency of episodes of oxygen desaturation. Secondary outcomes are the number of the cardiorespiratory events, FiO2 necessity, newborn pain score evaluation, synchronization index, and thoracoabdominal asynchrony. The calculated sample size was of 30 patients. Discussion It is known that NIPPV produces a percentage of ineffective acts due to asynchronies between the ventilator and the infant’s breaths. On the other hand, an ineffective synchronization could increase work of breathing. Our hypothesis is that an efficient synchronization could reduce the respiratory work and increase the volume per minute exchanged without interfering with the natural respiratory rhythm of the patient with RDS. The results of this study will allow us to evaluate the effectiveness of the synchronization, demonstrating whether SNIPPV is the most effective non-invasive ventilation mode in preterm infants with RDS at their first approach to NIV ventilation. Trial registration ClinicalTrials.gov NCT03289936 . Registered on September 21, 2017

Enteral Nutrition Tolerance And REspiratory Support (ENTARES) Study in preterm infants: study protocol for a randomized controlled trial

Abstract Background Respiratory distress syndrome (RDS) and feeding intolerance are common conditions in preterm infants and among the major causes of neonatal mortality and morbidity. For many years, preterm infants with RDS have been treated with mechanical ventilation, increasing risks of acute lung injury and bronchopulmonary dysplasia. In recent years non-invasive ventilation techniques have been developed. Showing similar efficacy and risk of bronchopulmonary dysplasia, nasal continuous positive airway pressure (NCPAP) and heated humidified high-flow nasal cannula (HHHFNC) have become the most widespread techniques in neonatal intensive care units. However, their impact on nutrition, particularly on feeding tolerance and risk of complications, is still unknown in preterm infants. The aim of the study is to evaluate the impact of NCPAP vs HHHFNC on enteral feeding and to identify the most suitable technique for preterm infants with RDS. Methods A multicenter randomized single-blind controlled trial was designed. All preterm infants with a gestational age of 25–29 weeks treated with NCPAP or HHHFNC for RDS and demonstrating stability for at least 48 h along with the compliance with inclusion criteria (age less than 7 days, need for non-invasive respiratory support, suitability to start enteral feeding) will be enrolled in the study and randomized to the NCPAP or HHHFNC arm. All patients will be monitored until discharge, and data will be analyzed according to an intention-to-treat model. The primary outcome is the time to reach full enteral feeding, while parameters of respiratory support, feeding tolerance, and overall health status will be evaluated as secondary outcomes. The sample size was calculated at 141 patients per arm. Discussion The identification of the most suitable technique (NCPAP vs HHHFNC) for preterm infants with feeding intolerance could reduce gastrointestinal complications, improve growth, and reduce hospital length of stay, thus improving clinical outcomes and reducing health costs. The evaluation of the timing of oral feeding could be useful in understanding the influence that these techniques could have on the development of sucking-swallow coordination. Moreover, the evaluation of the response to NCPAP and HHHFNC could clarify their efficacy as a treatment for RDS in extremely preterm infants. Trial registration ClinicalTrials.gov, NCT03548324. Registered on 7 June 2018

Exome sequencing and pathway analysis for identification of genetic variability relevant for bronchopulmonary dysplasia (BPD) in preterm newborns: A pilot study

Background: Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in infancy, affecting preterm children with low birth weight. The disease has a multifactorial aetiology with a significant genetic component; until now published association studies have identified several candidate genes but only few of these data has been replicated. In this pilot study, we approached exome sequencing aimed at identifying non-common variants, which are expected to have a stronger phenotypic effect. Materials and methods: We performed this study on 26 Italian severely affected BPD preterm unrelated newborns, homogeneously selected from a large prospective cohort. We used an Illumina HiSeq 2000 for sequencing. Data analysis was focussed on genes previously associated to BPD susceptibility and to new candidates in related pathways, highlighted by a prioritization analysis performed using ToppGene Suite. Results: By exome sequencing, we identified 3369 novel variants, with a median of 400 variations per sample. The top candidate genes highlighted were NOS2, MMP1, CRP, LBP and the toll-like receptor (. TLR) family. All of them have been confirmed with Sanger sequencing. Conclusions: Potential candidate genes have been discovered in this preliminary study; the pathogenic role of identified variants will need to be confirmed with functional and segregation studies and possibly with further methods, able to evaluate the collective influence of rare variants.Moreover, additional candidates will be tested and genetic analysis will be extended to all affected children

Exome sequencing and pathway analysis for identification of genetic variability relevant for bronchopulmonary dysplasia (BPD) in preterm newborns: A pilot study

Background: Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in infancy, affecting preterm children with low birth weight. The disease has a multifactorial aetiology with a significant genetic component; until now published association studies have identified several candidate genes but only few of these data has been replicated. In this pilot study, we approached exome sequencing aimed at identifying non-common variants, which are expected to have a stronger phenotypic effect. Materials and methods: We performed this study on 26 Italian severely affected BPD preterm unrelated newborns, homogeneously selected from a large prospective cohort. We used an Illumina HiSeq 2000 for sequencing. Data analysis was focussed on genes previously associated to BPD susceptibility and to new candidates in related pathways, highlighted by a prioritization analysis performed using ToppGene Suite. Results: By exome sequencing, we identified 3369 novel variants, with a median of 400 variations per sample. The top candidate genes highlighted were NOS2, MMP1, CRP, LBP and the toll-like receptor (. TLR) family. All of them have been confirmed with Sanger sequencing. Conclusions: Potential candidate genes have been discovered in this preliminary study; the pathogenic role of identified variants will need to be confirmed with functional and segregation studies and possibly with further methods, able to evaluate the collective influence of rare variants.Moreover, additional candidates will be tested and genetic analysis will be extended to all affected children

Fetal monitoring indications for delivery and 2-year outcome in 310 infants with fetal growth restriction delivered before 32 weeks' gestation in the TRUFFLE study

Objective: In the TRUFFLE (Trial of Randomized Umbilical and Fetal Flow in Europe) study on the outcome of early fetal growth restriction, women were allocated to one of three groups of indication for delivery according to the following monitoring strategies: (1) reduced fetal heart rate (FHR) short-term variation (STV) on cardiotocography (CTG); (2) early changes in fetal ductus venosus (DV) waveform (DV-p95); and (3) late changes in fetal DV waveform (DV-no-A). However, many infants per monitoring protocol were delivered because of safety-net criteria, for maternal or other fetal indications, or after 32 weeks of gestation when the protocol was no longer applied. The objective of the present posthoc subanalysis was to investigate the indications for delivery in relation to 2-year outcome in infants delivered before 32 weeks to further refine management proposals. Methods: We included all 310 cases of the TRUFFLE study with known outcome at 2 years' corrected age and seven fetal deaths, excluding seven cases with inevitable perinatal death. Data were analyzed according to the allocated fetal monitoring strategy in combination with the indication for delivery. Results: Overall, only 32% of liveborn infants were delivered according to the specified monitoring parameter for indication for delivery; 38% were delivered because of safety-net criteria, 15% for other fetal reasons and 15% for maternal reasons. In the CTG-STV group, 51% of infants were delivered because of reduced STV. In the DV-p95 group, 34% of infants were delivered because of abnormal DV and, in the DV-no-A group, only 10% of infants were delivered accordingly. The majority of infants in the DV groups were delivered for the safety-net criterion of spontaneous decelerations in FHR. Two-year intact survival was highest in the DV groups combined compared with the CTG-STV group (P = 0.05 for live births only, P = 0.21 including fetal death), with no difference between DV groups. A poorer outcome in the CTG-STV group was restricted to infants delivered because of FHR decelerations in the safety-net subgroup. Infants delivered because of maternal reasons had the highest birth weight and a non-significantly higher intact survival. Conclusions: In this subanalysis of infants delivered before 32 weeks, the majority were delivered for reasons other than the allocated monitoring strategy indication. Since, in the DV group, CTG-STV criteria were used as a safety net but in the CTG-STV group, no DV safety-net criteria were applied, we speculate that the slightly poorer outcome in the CTG-STV group might be explained by the absence of DV data. The optimal timing of delivery of fetuses with early intrauterine growth restriction may therefore be best determined by monitoring them longitudinally, with both DV and CTG monitoring