The NYCKidSeq randomized controlled trial: Impact of GUÍA digitally enhanced genetic results disclosure in diverse families.

Digital solutions are needed to support rapid increases in the application of genetic/genomic tests (GTs) in diverse clinical settings and patient populations. We developed GUÍA, a bilingual digital application that facilitates disclosure of GT results. The NYCKidSeq randomized controlled trial enrolled diverse children with neurologic, cardiac, and immunologic conditions who underwent GTs. The trial evaluated GUÍA's impact on understanding the GT results by randomizing families to results disclosure genetic counseling with GUÍA (intervention) or standard of care (SOC). Parents/legal guardians (participants) completed surveys at baseline, post-results disclosure, and 6 months later. Survey measures assessed the primary study outcomes of participants' perceived understanding of and confidence in explaining their child's GT results and the secondary outcome of objective understanding. The analysis included 551 diverse participants, 270 in the GUÍA arm and 281 in SOC. Participants in the GUÍA arm had significantly higher perceived understanding post-results (OR = 2.8, CI[1.004, 7.617], p = 0.049) and maintained higher objective understanding over time (OR = 1.1, CI[1.004, 1.127], p = 0.038) compared to SOC. There was no impact on perceived confidence. Hispanic/Latino(a) individuals in the GUÍA arm maintained higher perceived understanding (OR = 3.9, CI[1.603, 9.254], p = 0.003), confidence (OR = 2.7, CI[1.021, 7.277], p = 0.046), and objective understanding (OR = 1.1, CI[1.009, 1.212], p = 0.032) compared to SOC. This trial demonstrates that GUÍA positively impacts understanding of GT results in diverse parents of children with suspected genetic conditions and builds a case for utilizing GUÍA to deliver complex results. Continued development and evaluation of digital applications in diverse populations are critical for equitably scaling GT offerings in specialty clinics.

Molecular diagnostic yield of genome sequencing versus targeted gene panel testing in racially and ethnically diverse pediatric patients.

PURPOSE: Adoption of genome sequencing (GS) as a first-line test requires evaluation of its diagnostic yield. We evaluated the GS and targeted gene panel (TGP) testing in diverse pediatric patients (probands) with suspected genetic conditions. METHODS: Probands with neurologic, cardiac, or immunologic conditions were offered GS and TGP testing. Diagnostic yield was compared using a fully paired study design. RESULTS: A total of 645 probands (median age 9 years) underwent genetic testing, and 113 (17.5%) received a molecular diagnosis. Among 642 probands with both GS and TGP testing, GS yielded 106 (16.5%) and TGPs yielded 52 (8.1%) diagnoses (P < .001). Yield was greater for GS vs TGPs in Hispanic/Latino(a) (17.2% vs 9.5%, P < .001) and White/European American (19.8% vs 7.9%, P < .001) but not in Black/African American (11.5% vs 7.7%, P = .22) population groups by self-report. A higher rate of inconclusive results was seen in the Black/African American (63.8%) vs White/European American (47.6%; P = .01) population group. Most causal copy number variants (17 of 19) and mosaic variants (6 of 8) were detected only by GS. CONCLUSION: GS may yield up to twice as many diagnoses in pediatric patients compared with TGP testing but not yet across all population groups.

Identification of copy number variants with genome sequencing: Clinical experiences from the NYCKidSeq program.

Copy number variations (CNVs) play a significant role in human disease. While chromosomal microarray has traditionally been the first-tier test for CNV detection, use of genome sequencing (GS) is increasing. We report the frequency of CNVs detected with GS in a diverse pediatric cohort from the NYCKidSeq program and highlight specific examples of its clinical impact. A total of 1052 children (0-21 years) with neurodevelopmental, cardiac, and/or immunodeficiency phenotypes received GS. Phenotype-driven analysis was used, resulting in 183 (17.4%) participants with a diagnostic result. CNVs accounted for 20.2% of participants with a diagnostic result (37/183) and ranged from 0.5 kb to 16 Mb. Of participants with a diagnostic result (n = 183) and phenotypes in more than one category, 5/17 (29.4%) were solved by a CNV finding, suggesting a high prevalence of diagnostic CNVs in participants with complex phenotypes. Thirteen participants with a diagnostic CNV (35.1%) had previously uninformative genetic testing, of which nine included a chromosomal microarray. This study demonstrates the benefits of GS for reliable detection of CNVs in a pediatric cohort with variable phenotypes.

Detection of mosaic variants using genome sequencing in a large pediatric cohort.

The increased use of next-generation sequencing has expanded our understanding of the involvement and prevalence of mosaicism in genetic disorders. We describe a total of eleven cases: nine in which mosaic variants detected by genome sequencing (GS) and/or targeted gene panels (TGPs) were considered to be causative for the proband's phenotype, and two of apparent parental mosaicism. Variants were identified in the following genes: PHACTR1, SCN8A, KCNT1, CDKL5, NEXMIF, CUX1, TSC2, GABRB2, and SMARCB1. In addition, we identified one large duplication including three genes, UBE3A, GABRB3, and MAGEL2, and one large deletion including deletion of ARFGAP1, EEF1A2, CHRNA4, and KCNQ2. All patients were enrolled in the NYCKidSeq study, a research program studying the communication of genomic information in clinical care, as well as the clinical utility and diagnostic yield of GS for children with suspected genetic disorders in diverse populations in New York City. We observed variability in the correlation between reported variant allele fraction and the severity of the patient's phenotype, although we were not able to determine the mosaicism percentage in clinically relevant tissue(s). Although our study was not sufficiently powered to assess differences in mosaicism detection between the two testing modalities, we saw a trend toward better detection by GS as compared with TGP testing. This case series supports the importance of mosaicism in childhood-onset genetic conditions and informs guidelines for laboratory and clinical interpretation of mosaic variants detected by GS.

Parental experiences of live video streaming technology in neonatal care in England: a qualitative study.

BACKGROUND: The use of bedside cameras in neonatal units facilitates livestreaming of infants to support parental and family bonding when they are unable to be physically present with their baby. This study aimed to explore the experiences of parents of infants previously admitted for neonatal care and who used live video streaming to view their baby in real-time. METHODS: Qualitative semi-structured interviews were conducted after discharge with parents of infants admitted for neonatal care on a tertiary level neonatal unit in the UK in 2021. Interviews were conducted virtually, transcribed verbatim and uploaded into NVivo V12 to facilitate analysis. Thematic analysis by two independent researchers was undertaken to identify themes representing the data. RESULTS: Seventeen participants took part in sixteen interviews. Thematic analysis identified 8 basic themes which were grouped into 3 organizational themes: (1) family integration of the baby including parent-infant, sibling-infant, and wider family-infant attachment facilitated through livestreaming, (2) implementation of the livestreaming service including communication, initial set up of the livestreaming service, and areas for improvement, and (3) parental control including emotional, and situational control. CONCLUSIONS: The use of livestreaming technology can provide parents with opportunities to integrate their baby into their wider family and friendship community and gain a sense of control over their baby's admission for neonatal care. On-going parental education around how to use, and what to expect from, livestreaming technology is required to minimise any potential distress from viewing their baby online.

The NeoPACE study: study protocol for the development of a core outcome set for neonatal palliative care.

BACKGROUND: Neonatal death is the leading category of death in children under the age of 5 in the UK. Many babies die following decisions between parents and the neonatal team; when a baby is critically unwell, with the support of healthcare professionals, parents may make the decision to stop active treatment and focus on ensuring their baby has a 'good' death. There is very little evidence to support the clinical application of neonatal palliative care and/or end-of-life care, resulting in variation in clinical provision between neonatal units. Developing core outcomes for neonatal palliative care would enable the development of measures of good practice and enhance our care of families. The aim of this study is to develop a core outcome set with associated tools for measuring neonatal palliative care. METHOD: This study has four phases: (1) identification of potential outcomes through systematic review and qualitative interviews with key stakeholders, including parents and healthcare professionals (2) an online Delphi process with key stakeholders to determine core outcomes (3) identification of outcome measures to support clinical application of outcome use (4) dissemination of the core outcome set for use across neonatal units in the UK. Key stakeholders include parents, healthcare professionals, and researchers with a background in neonatal palliative care. DISCUSSION: Developing a core outcome set will standardise minimum reported outcomes for future research and quality improvement projects designed to determine the effectiveness of interventions and clinical care during neonatal palliative and/or end-of-life care. The core outcome set will provide healthcare professionals working in neonatal palliative and/or end-of-life support with an increased and consistent evidence base to enhance practice in this area. TRIAL REGISTRATION: The study has been registered with the COMET initiative ( https://www.comet-initiative.org/Studies/Details/1470 ) and the systematic review is registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023451068).

End-of-Life Decision Making Between Doctors and Parents in NICU: The Development and Assessment of a Conversation Analysis Coding Framework.

We report the development and assessment of a novel coding framework in the context of research into neonatal end-of-life decision making conversations. Data comprised 27 formal conversations between doctors and parents of critically ill babies, recorded in two neonatal intensive care units. The coding framework was developed from a qualitative analysis of the recordings using the method of conversation analysis (CA). Codes underpinned by our qualitative analysis had in the main moderate to strong agreement (inter-rater reliability) between coders; three codes had lower agreement reflecting the use of euphemisms for death and disability. Coding these interactions confirmed the significance of the doctors' talk in terms of parental involvement in decision-making, whilst highlighting areas warranting further qualitative analysis. This quantifiable representation provides a novel outcome based on evidence that is internal to the conversation rather than influenced by other factors related to the baby's care or outcome.

Neonatal organ donation: Retrospective audit into potential donation in a single neonatal unit.

BACKGROUND: Research has shown that many babies who die in neonatal units could have been potential tissue and/or organ donors. Despite the existence of guidelines supporting its implementation, the incidence of neonatal donation remains rare in the United Kingdom. AIM: The aim of this audit was to retrospectively determine potential eligibility for neonatal tissue and/or organ donation referral in infants who died in a single UK tertiary-level neonatal unit between 2012 and 2021. Cause of death and documentation of any discussions held regarding referral for donation were also explored. STUDY DESIGN: An audit was undertaken to identify all neonatal deaths at a single tertiary-level NICU in London from 2012-2021. Infants who retrospectively could have been referred as potential tissue and/or organ donors were identified using current NHS Blood and Transplant inclusion and exclusion criteria. RESULTS AND CONCLUSION: A significant missed potential for neonatal tissue and/or organ donation referrals was identified, which is likely not just limited to the unit audited. Causes of death were as expected for a tertiary level neonatal unit and centre for therapeutic cooling of babies born with hypoxic perinatal brain injuries. Only one documented conversation was found regarding neonatal donation. RELEVANCE TO CLINICAL PRACTICE: To enable conversations regarding neonatal donation to become a routine part of end-of-life care discussions with families as appropriate, good links between neonatal healthcare professionals and Specialist Nurses in Organ Donation need to be established. This will facilitate the referral of all suitable neonates as potential donors and ensure that neonatal staff feel supported to care for babies identified as potential donors.

GUÍA: a digital platform to facilitate result disclosure in genetic counseling.

PURPOSE: Use of genomic sequencing is increasing at a pace that requires technological solutions to effectively meet the needs of a growing patient population. We developed GUÍA, a web-based application, to enhance the delivery of genomic results and related clinical information to patients and families. METHODS: GUÍA development occurred in five overlapping phases: formative research, content development, stakeholder/community member input, user interface design, and web application development. Development was informed by formative qualitative research involving parents (N = 22) whose children underwent genomic testing. Participants enrolled in the NYCKidSeq pilot study (N = 18) completed structured feedback interviews post-result disclosure using GUÍA. Genetic specialists, researchers, patients, and community stakeholders provided their perspectives on GUÍA's design to ensure technical, cultural, and literacy appropriateness. RESULTS: NYCKidSeq participants responded positively to the use of GUÍA to deliver their children's results. All participants (N = 10) with previous experience with genetic testing felt GUÍA improved result disclosure, and 17 (94%) participants said the content was clear. CONCLUSION: GUÍA communicates complex genomic information in an understandable and personalized manner. Initial piloting demonstrated GUÍA's utility for families enrolled in the NYCKidSeq pilot study. Findings from the NYCKidSeq clinical trial will provide insight into GUÍA's effectiveness in communicating results among diverse, multilingual populations.

'We did everything we could'- a qualitative study exploring the acceptability of maternal-fetal surgery for spina bifida to parents.

OBJECTIVE: To explore the concepts and strategies parents employ when considering maternal-fetal surgery (MFS) as an option for the management of spina bifida (SB) in their fetus, and how this determines the acceptability of the intervention. METHODS: A two-centre interview study enrolling parents whose fetuses with SB were eligible for MFS. To assess differences in acceptability, parents opting for MFS (n = 24) were interviewed at three different moments in time: prior to the intervention, directly after the intervention and 3-6 months after birth. Parents opting for termination of pregnancy (n = 5) were interviewed only once. Themes were identified and organised in line with the framework of acceptability. RESULTS: To parents opting for MFS, the intervention was perceived as an opportunity that needed to be taken. Feelings of parental responsibility drove them to do anything in their power to improve their future child's situation. Expectations seemed to be realistic yet were driven by hope for the best outcome. None expressed decisional regret at any stage, despite substantial impact and, at times, disappointing outcomes. For the small group of participants, who decided to opt for termination of pregnancy (TOP), MFS was not perceived as an intervention that substantially could improve the quality of their future child's life. CONCLUSION: Prospective parents opting for MFS were driven by their feelings of parental responsibility. They recognise the fetus as their future child and value information and care focusing on optimising the child's future health. In the small group of parents opting for TOP, MFS was felt to offer insufficient certainty of substantial improvement in quality of life and the perceived severe impact of SB drove their decision to end the pregnancy.

Neonatal nursing led research activity in the UK: a survey of current practice.

BACKGROUND: Neonatal nurses are ideally placed in practice to undertake research enhancing the care of families. More information is required, however, around neonatal nursing led research to advance leadership in this area. The aim of this study was to determine neonatal nursing led research activity within the UK. METHODS: The study used a web-based survey design and neonatal nurses were eligible if they were working at or towards Masters or Doctoral level qualification in the UK. The survey was distributed to members of the Neonatal Nurses Association, UK Schools of Nursing and shared on social media pages of authors and professional organisations. Results were analysed using descriptive and frequency statistics and content analysis. RESULTS: Of the 56 respondents, 14% (n = 8) had a Doctoral level qualification and 43% (n = 24) of participants held a Masters qualification. Lack of time and funding knowledge was the largest barrier to research. Only 30% (n = 3) of participants had a research mentor and only 18% (n = 3) were from a neonatal nursing background. CONCLUSIONS: There are limited numbers of neonatal nurses undertaking or leading nursing research in the UK. Further support is required to enhance clinical academic career trajectories to ensure research is a viable pathway for future generations of neonatal nurses.

Neonatal nursing during the COVID-19 global pandemic: A thematic analysis of personal reflections.

BACKGROUND: The COVID-19 pandemic has resulted in significant changes and restrictions to neonatal care. The aim of this study was to explore the impact of these changes on neonatal nurses globally. METHODS: We conducted a thematic analysis on written reflections by neonatal nurses worldwide, exploring their experiences of COVID-19. Twenty-two reflections were analysed from eleven countries. RESULTS: Thematic analysis revealed 4 main themes relating to the nurses' role: 1) protector 2) challenges to human quality of care 3) vulnerability and 4) resilience. The measures taken as protector were described as compromising the human qualities of care fundamental to their role. This tension, together with other new challenges, heightened feelings of vulnerability. Concurrently, nurses identified role resilience, including resourcefulness and peer support, which allowed them to navigate the global pandemic. CONCLUSION: By identifying global challenges and strategies to overcome these, neonatal nurses may be better equipped as the pandemic continues. The reflections underscore the importance of family integrated care and the tension created when it is compromised.

Documentation in the neonatal unit: The support given to parents and their participation in their baby's care.

AIMS: The aim of this study was to explore how often the participation of parents in their infants' care and professionals' support for parents was documented in the clinical records and to determine how such participation and support were documented. BACKGROUND: Comprehensive documentation can facilitate collaboration between parents and healthcare professionals, supporting family-centred care, yet little is known about how this is reflected in practice. DESIGN: A prospective, mixed methods approach was used to analyse the clinical records of newborns. METHODS: The study was carried out in a large tertiary Neonatal Unit in the United Kingdom, from 2013 - 2014. We analysed the clinical records of 24 critically ill newborns using content analysis and thematic analysis, enabling us to determine the frequency of documented support and participation and how support and participation were documented. RESULTS: We identified four categories of support in the clinical records: "emotional", "spiritual", "social" and "practical support". We also identified instances where parents were encouraged to participate in their infant's care. Frequency differences in the documentation of support between infants facing a redirection of care decision and infants receiving active treatment were found. Two organisational themes were identified: "task focused documentation" and "minimal documentation of parental role". These were grouped together under the global theme "professional accountability". The perspectives and experiences of parents were minimally documented throughout. CONCLUSION: Documentation of support towards parents and parents' participation in their infants' care was limited in terms of frequency and content. Encouraging regular, detailed documentation of these aspects of care may facilitate family-centred care.

Nursing & parental perceptions of neonatal care in Central Vietnam: a longitudinal qualitative study.

BACKGROUND: Neonatal mortality accounts for nearly three quarters of all infant deaths in Vietnam. The nursing team are the largest professional group working with newborns, however do not routinely receive neonatal training and there is a lack of research into the impact of educational provision. This study explored changes in nursing perceptions towards their role following a neonatal educational intervention. Parents perceptions of nursing care were explored to determine any changes as nurses gained more experience. METHOD: Semi-Structured qualitative interviews were conducted every 6 months over an 18 month period with 16 nurses. At each time point, parents whose infant was resident on the neonatal unit were invited to participate in an interview to explore their experiences of nursing care. A total of 67 parents participated over 18 months. Interviews were conducted and transcribed in Vietnamese before translation into English for manifest content analysis facilitated by NVivo V14. RESULTS: Analysis of nursing transcripts identified 14 basic categories which could be grouped (23) into 3 themes: (1) perceptions of the role of the neonatal nurse, (2) perception of the parental role and (3) professional recollections. Analysis of parent transcripts identified 14 basic categories which could be grouped into 3 themes: (1) information sharing, (2) participation in care, and (3) personal experience. CONCLUSIONS: Qualitative interviews highlighted the short term effect that the introduction of an educational intervention can have on both nursing attitudes towards and parental experience of care in one neonatal unit in central Vietnam. Nurses shared a growing awareness of their role along with its ethical issues and challenges, whilst parents discussed their overall desire for more participation in their infants care. Further research is required to determine the long term impact of the intervention, the ability of nurses to translate knowledge into clinical practice through assessment of nursing knowledge and competence, and the impact and needs of parents. A greater understanding will allow us to continue to improve the experiences of nurses and parents, and highlight how these areas may contribute towards the reduction of infant mortality and morbidity in Vietnam.

Parental involvement in neonatal critical care decision-making.

The article analyses the decision-making process between doctors and parents of babies in neonatal intensive care. In particular, it focuses on cases in which the decision concerns the redirection of care from full intensive care to palliative care at the end of life. Thirty one families were recruited from a neonatal intensive care unit in England and their formal interactions with the doctor recorded. The conversations were transcribed and analysed using conversation analysis. Analysis focused on sequences in which decisions about the redirection of care were initiated and progressed. Two distinct communicative approaches to decision-making were used by doctors: 'making recommendations' and 'providing options'. Different trajectories for parental involvement in decision-making were afforded by each design, as well as differences in terms of the alignments, or conflicts, between doctors and parents. 'Making recommendations' led to misalignment and reduced opportunities for questions and collaboration; 'providing options' led to an aligned approach with opportunities for questions and fuller participation in the decision-making process. The findings are discussed in the context of clinical uncertainty, moral responsibility and the implications for medical communication training and guidance. A Virtual Abstract of this paper can be accessed at: https://www.youtube.com/watch?v=MyuymxDNupk&feature=youtu.be.

Capturing Psychologists' Work in Academic Health Settings: The Role of the Educational Value Unit (EVU).

This paper describes how psychology faculty positions in academic health centers (AHCs) have evolved to meet the changing needs in healthcare. In that context, the roles of psychologists have expanded significantly to include a wide array of clinical responsibilities, teaching and supervisory roles, administrative functions, research initiatives, and academic scholarship. Traditionally, faculty compensation plans have been calculated through the use of Relative Value Units which are primarily based on clinical service delivery, hence, incomplete when attempting to account for these growing academic responsibilities. This paper reviews the need to expand the ways in which the work provided by psychologists is appropriately identified and compensated for in AHCs. Drawing upon six models utilized in other areas of medical education, this paper describes the potential utility of incorporating Educational Value Units as a metric for capturing this expanding set of academic responsibilities and systematically incorporating them into a psychologist's job design. Recommendations for future considerations are provided.

'I don't want him to always be so far behind': Parental perceptions of child independence in the context of extreme prematurity; a qualitative study.

This study addresses the paucity of research on parents of extremely preterm adolescents (born <27 weeks of gestation) and their experiences within the framework of parental determinism. We conducted semi-structured interviews with twenty-two mothers and one father. Data were analysed thematically, revealing three overarching themes and eight subthemes shaping parental accounts. These themes centred on parental ambitions for their children, their perceptions of their child's abilities, and the parenting behaviours employed to support parental aspirations. Parents' actions were influenced by their ambitions and the belief that they could impact their child's future independence. While some parents adopted 'trusting', non-intensive parenting behaviours, those anticipating challenges for their child's future independence resorted to intensive parenting practices. These findings align with the concept of parental determinism, emphasising the perceived causal link between present parental actions and future child outcomes. In the context of extreme prematurity, a nuanced understanding of parental perceptions regarding their child's future independence aligned with a delicate balance between hope and realistic aspiration is crucial for enhancing parental support and well-being.

Investigating Father or Partner Involvement in Family Integrated Care in Neonatal Units: Protocol for a Prospective, Multicenter, Multiphase Study

BACKGROUND: Neonatal unit (NU) admissions for premature babies can last for months, which can significantly impact parental mental health (MH) with symptoms of depression, stress, and anxiety. Literature suggests fathers experience comparable MH symptoms to mothers. Family integrated care (FICare) is a culture where parents are collaborators and partners in caring for their hospitalized newborns. FICare improves infant outcomes and maternal MH. Similar reports on fathers are limited. OBJECTIVE: The primary aim of this study is to investigate the impact of supporting father or partner engagement in FICare of preterm infants on their MH up to 6 weeks postdischarge. The secondary aim is to investigate the impact on maternal MH. METHODS: This is a 2-phase study: phase 1 to gather baseline information and phase 2 to assess the impact of enhanced father or partner engagement in FICare on their MH, involving 2 NUs (tertiary and level 2). Enhanced FICare will be developed and introduced (eg, information booklet, workbook, classes, and a father peer-support group) alongside standard FICare practices. Father or partner MH will be assessed with semistructured qualitative interviews and validated questionnaires: Generalized Anxiety Disorder Assessment, Patient Health Questionnaire, and Parental Stressor Scale: Neonatal Intensive Care Unit from NU admission to 6 weeks postdischarge. Mothers will be assessed by focus groups and the same questionnaires. Descriptive statistics and appropriate comparative tests, such as the 2-tailed t test, will be used to analyze and compare phase 1 and 2 data. Qualitative data will be coded line by line with the use of NVivo (Lumivero) and thematically analyzed. Simultaneously, systematic reviews (SRs) of fathers' experiences of FICare and their MH outcomes will be conducted. The study was approved by the National Research Ethics Committee (22/EM/0140) in August 2022. A parent advisory group was formed to advise on the study methodology, materials, involvement of participant parents, and dissemination of study findings. RESULTS: A recent SR demonstrated that data saturation is likely to be achieved by interviewing 9 to 17 participants. We will study a maximum of 20 parents of infants born at less than 33 weeks' gestation in each phase. As of October 2023, the study was ongoing. The SR studies are registered with the PROSPERO database (324275 and 306760). The projected end date for data collection is July 2024; data analysis will be conducted in November 2024 and publication will occur in 2025. CONCLUSIONS: The study aims to demonstrate the feasibility of using a father or partner-sensitive FICare model for parents of premature babies with a positive impact on their MH. It will demonstrate the feasibility of providing FICare to extremely premature babies receiving intensive care. This study may support the development of inclusive FICare guidelines for nonbirthing parents and their extremely premature infants. TRIAL REGISTRATION: ClinicalTrials.gov: NCT06022991; https://classic.clinicaltrials.gov/ct2/show/NCT06022991. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/53160.

Correction: Investigating Father or Partner Involvement in Family Integrated Care in Neonatal Units: Protocol for a Prospective, Multicenter, Multiphase Study.

[This corrects the article DOI: 10.2196/53160.].

Epigenetic Priming Enhances Chondrogenic Potential of Expanded Chondrocytes.

Expansion of chondrocytes presents a major obstacle in the cartilage regeneration procedure, such as matrix-induced autologous chondrocyte implantation. Dedifferentiation of chondrocytes during the expansion process leads to the emergence of a fibrotic (chondrofibrotic) phenotype that decreases the chondrogenic potential of the implanted cells. We aim to (1) determine the extent that chromatin architecture of H3K27me3 and H3K9me3 remodels during dedifferentiation and persists after the transfer to a three-dimensional (3D) culture; and (2) to prevent this persistent remodeling to enhance the chondrogenic potential of expanded bovine chondrocytes, used as a model system. Chromatin architecture remodeling of H3K27me3 and H3K9me3 was observed at 0 population doublings, 8 population doublings, and 16 population doublings (PD16) in a two-dimensional (2D) culture and after encapsulation of the expanded chondrocytes in a 3D hydrogel culture. Chondrocytes were treated with inhibitors of epigenetic modifiers (epigenetic priming) for PD16 and then encapsulated in 3D hydrogels. Chromatin architecture of chondrocytes and gene expression were evaluated before and after encapsulation. We observed a change in chromatin architecture of epigenetic modifications H3K27me3 and H3K9me3 during chondrocyte dedifferentiation. Although inhibiting enzymes that modify H3K27me3 and H3K9me3 did not alter the dedifferentiation process in 2D culture, applying these treatments during the 2D expansion did increase the expression of select chondrogenic genes and protein deposition of type II collagen when transferred to a 3D environment. Overall, we found that epigenetic priming of expanded bovine chondrocytes alters the cell fate when chondrocytes are later encapsulated into a 3D environment, providing a potential method to enhance the success of cartilage regeneration procedures.