Prevalence, correlates, and mental health outcomes of social jetlag in Chinese school-age adolescents: A large-scale population-based study.

BACKGROUND: This cross-sectional study aimed to examine the prevalence and correlates of social jetlag (SJL) in Chinese adolescents, as well as to test the relationships between SJL and mental health problems. METHODS: A total of 106979 students (Mage = 13.0 ± 1.8 years; Nmale = 58296 [54.5 %]) from Shenzhen, China completed an online survey from May 24th to June 5th, 2022. Information on sociodemographics, lifestyles, sleep characteristics, anxiety symptoms, and depressive symptoms was collected by a self-administered questionnaire. Multivariate and binary logistic regression were adopted for data analysis. RESULTS: 17.8 % of participants experienced SJL ≥ 2 h. To adjust the accumulated sleep debt, sleep-corrected SJL (SJLsc) was calculated and 8.3 % of individuals self-reported SJLsc ≥ 2 h. Both SJL and SJLsc show an increasing trend with age. Risk factors of SJL included females, poor parental marital status, being overweight, physically inactive, smoking, drinking, and having a late chronotype. Moreover, males, having siblings, boarding at school, short sleep duration, experiencing insomnia, and frequent nightmares were significantly associated with an increased risk of SJLsc. After adjusting for all covariates, adolescents with SJLsc ≥ 2 h were more likely to have anxiety symptoms (OR: 1.35, 95 % CI: 1.24-1.48) and depressive symptoms (OR: 1.35, 95 % CI: 1.25-1.46) than those with SJLsc < 1 h. CONCLUSIONS: SJL is common among Chinese school-age adolescents. This study is valuable for the development of prevention and intervention strategies for SJL in adolescents at the population level. Additionally, the strong links between SJLsc and emotional problems underscore the critical significance of addressing SJL as a key aspect of adolescent well-being.

Loneliness, perceived social support, and their changes predict medical adherence over 12 months among patients with coronary heart disease.

OBJECTIVES: This study investigated whether changes in loneliness and perceived social support predicted medical adherence in patients with coronary heart disease (CHD) over 12 months. Moreover, short-term and long-term buffering effects of social support on the association between loneliness and medical adherence were systematically examined. DESIGN: A three-wave longitudinal study. METHODS: Participants were 255 CHD patients with a mean age of 63 years. Medical adherence, loneliness, and perceived social support were assessed at baseline, 3 months, and 12 months. Hierarchical regression analyses were conducted to examine the influences of loneliness and social support as well as their changes on medical adherence over 12 months. Moderation analyses were performed to test buffering effects of baseline social support and its changes against loneliness and its changes, respectively. RESULTS: Changes in loneliness significantly predicted medical adherence at 12 months (ß = -.23, p = .001) but not at 3 months (ß = -.10, p = .142). Changes in social support predicted medical adherence at both 3 (ß = .23, p = .002) and 12 months (ß = .26, p = .001). Social support concurrently buffered the adverse impact of loneliness on medical adherence (B = .29, SE = .12, p = .020) at baseline but did not at 3 or 12 months (Bs = -.21 to .40, SEs = .12 to .30, ps = .177 to .847). CONCLUSIONS: Findings highlight the importance of monitoring loneliness and perceived social support continuously over time for CHD patients to promote medical adherence.

A longitudinal study on the effects of social support on self-stigma, psychiatric symptoms, and personal and social functioning in community patients with severe mental illnesses in China.

BACKGROUND: Few studies have examined whether social support contributes to better consequences among chronic patients with severe mental illnesses (SMI) in their community recovery stage and whether self-stigma would be a mechanism through which social support impacts psychiatric symptoms and personal and social functioning. AIMS: This study aimed to examine prospective associations of social support with long-term self-stigma, psychiatric symptoms, and personal and social functioning, and to investigate whether self-stigma would mediate the associations of social support with psychiatric symptoms and personal and social functioning among patients with SMI. METHODS: A total of 312 persons with SMI (schizophrenia and bipolar disorder) in their community recovery stage participated in the study. Social support, self-stigma, psychiatric symptoms, and personal and social functioning were evaluated at baseline. The follow-up assessment was conducted at 6 months with the baseline measures except for social support. Hierarchical linear regression and mediation analysis were performed. RESULTS: The results showed that baseline social support predicted decreases in stigma (ß = -.115, p = .029) and psychiatric symptoms (ß = -.193, p < .001), and increases in personal and social functioning (ß = .134, p = .008) over 6 months, after adjusting for relevant covariates. Stigma at 6 months partially mediated the association between baseline social support and 6-month psychiatric symptoms (indirect effect: ß = -.043, CI [-0.074, -0.018]). Stigma and psychiatric symptoms at 6 months together mediated the association between baseline social support and 6-month personal and social functioning (indirect effect: ß = .084, 95% CI [0.029, 0.143]). CONCLUSION: It is necessary to provide comprehensive social support services and stigma reduction interventions at the community level to improve the prognosis of SMI.

Sleep disturbance and suicidal ideation mediated by psychotic-like experiences in adolescents: a two-wave longitudinal study.

STUDY OBJECTIVES: Sleep disturbance may cause suicidal ideation (SI). This study aimed to examine their co-occurrence rate among adolescents and investigate whether psychotic-like experiences (PLEs) mediate this association. METHODS: A total of 17 722 Chinese adolescents were included in this two-wave longitudinal study. The baseline survey (time 1, T1) was conducted between April 21 and May 12, 2021, and the follow-up survey (time 2, T2) was implemented between December 17 and 26, 2021. At T1, participants completed questionnaires to assess their sleep disturbance, sleep duration, PLEs, SI, depressive symptoms, and sociodemographic characteristics. At T2, participants reported their PLEs, SI, and negative life events. RESULTS: The SI prevalence decreased from 20.2% (T1) to 18.4% (T2). Participants with SI showed significantly higher prevalence of sleep disturbance and short sleep duration compared to those without SI. Baseline sleep disturbance and short sleep duration were both associated with the increased risk of SI 6 months later. These longitudinal links were mediated by PLEs, independent of baseline covariates and negative life events. CONCLUSIONS: These findings provide a novel insight into the mechanism linking sleep problems and suicidality, and stress the significance of assessing and addressing sleep problems and PLEs for adolescent suicide prevention and intervention.

Tobacco smoking, second-hand smoking exposure in relation to psychotic-like experiences in adolescents.

BACKGROUND: Previous literature supports that tobacco smoking and second-hand smoking (SHS) exposure were strongly associated with poor mental health in the general population. However, there is a lack of empirical data on the relationship between tobacco smoking, SHS exposure and psychotic-like experiences (PLEs). This study conducted a cross-sectional survey to explore PLEs and the associations of PLEs with tobacco smoking and SHS exposure among adolescents in China. METHODS: A total sample of 67 182 Chinese adolescents were recruited from Guangdong province in China (53.7% boys, mean age = 12.79 years) from December 17 to 26, 2021. All adolescents have completed self-reported questionnaires on demographic characteristics, smoking status, SHS exposure and PLEs. RESULTS: Within the sample, only 1.2% of participants had an experience of tobacco smoking while approximately three-fifths reported being exposed to SHS. 10.7% of adolescents reported frequent PLEs over the past month. Adolescents who smoked showed a higher prevalence of PLEs than in non-smoking samples. After controlling for confounders, SHS exposure was a robust risk factor for PLEs with or without the effect of tobacco smoking. DISCUSSION: These findings support the importance of smoke-free legislation, and anti-smoking measures in educational settings directed at both adolescents and their caregiver, which may decrease occurring rates of PLEs among adolescents.

Changes in sleep disturbance among Chinese adolescents: A population-based online survey.

OBJECTIVE: Sleep disturbance is prevalent among adolescents but little is known about the short-term changes among Chinese adolescents. The study aimed to explore the prevalence and change patterns of sleep disturbance and identify its risk and protective factors. METHODS: Data were collected online from April 21st to May 12th, 2021 (Time 1, T1) and December 17th to 26th, 2021 (Time 2, T2). The final sample comprised 34,260 adolescents. Self-administrated questionnaires were used to assess socio-demographic variables, sleep disturbance, depression, anxiety, life events, family function, and resilience. RESULTS: The prevalence of sleep disturbance was 12.0% at T1 and 11.8% at T2, with higher rates in females than males. Four groups of sleep disturbance change patterns were identified: non-sleep disturbance group (80.4%), persistent group (4.2%), new-onset group (7.6%), and remission group (7.8%). Risk factors for new-onset sleep disturbance included being in junior high school (AOR = 1.26, 95%CI = 1.15-1.38), family history of mental disorders (AOR = 1.49, 95%CI = 1.03-2.15), and moderate (AOR = 1.24, 95%CI = 1.13-1.36) and severe (AOR = 1.48, 95%CI = 1.27-1.72) family dysfunction. Risk factors for persistent sleep disturbance included being in junior (AOR = 1.25, 95%CI = 1.08-1.45) and senior (AOR = 1.53, 95%CI = 1.15-2.03) high school, parental currently unmarried status (AOR = 1.34, 95%CI = 1.05-1.73), moderate (AOR = 1.19, 95%CI = 1.02-1.39) and severe (AOR = 1.28, 95%CI = 1.06-1.55) family dysfunction. Medium (AOR = 0.48, 95%CI = 0.43-0.53) and high (AOR = 0.34, 95%CI = 0.29-0.40) levels of resilience were protective factors against new-onset sleep disturbance, as well as against persistent sleep disturbance (medium level: AOR = 0.51, 95%CI = 0.43-0.60; high level: AOR = 0.32, 95%CI = 0.25-0.43). CONCLUSIONS: Interventions aimed at promoting family functions and enhancing resilience may improve sleep disturbance among adolescents.

Relationship between sleep disturbance and burnout among Chinese urban teachers: Moderating roles of resilience.

BACKGROUND: Sleep disturbance and burnout are prevalent among primary and secondary school teachers. Nevertheless, little is known about the relationship between sleep disturbance and burnout, and the mechanisms connecting this link. Our study aimed to explore the relationship between sleep disturbance and burnout among urban teachers, as well as to investigate this influencing mechanism further with resilience as a moderator. METHODS: 14,218 primary and secondary school teachers provided valid data. We assessed demographic information, sleep disturbance, burnout, and resilience. Multivariable logistic regression, Spearman correlation, and moderation analyses were used to evaluate the relationship between sleep disturbance and burnout and the moderating role of resilience. RESULTS: Of the participants, the prevalence of sleep disturbance and sleep deprivation among teachers was 20.0% and 31.7%, respectively. Additionally, 58.4% of teachers reported moderate or severe burnout, and 15.3% had both sleep disturbance and burnout. Sleep disturbance was significant and positively related to burnout. Resilience was found to moderate the association between sleep disturbance and burnout. CONCLUSIONS: These findings suggested strong associations between sleep disturbance and burnout. Interventions in improving resilience may protect teachers with sleep disturbance from burnout.

Associations Between Family Function and Non-suicidal Self-injury Among Chinese Urban Adolescents with and Without Parental Migration.

The study aims to explore the effect of family function on non-suicidal self-injury (NSSI) among Chinese urban adolescents with and without parental migration. Between April 21st to May 12th, 2021, adolescents were recruited from Shenzhen city of Guangdong province, China (n = 124,357). Of all the participants, 22,855 (18.4%) were left-behind children (LBC). Family function, NSSI, depression, and socio-demographic characteristics were assessed using a series of self-reported questionnaires. Urban LBC had a higher NSSI frequency, while a lower level of family function than non-LBC. After controlling for confounders, parental migration was significantly associated with NSSI, and family dysfunction was a robust risk factor for NSSI as well. The protective effect of family function on NSSI of LBC was stronger than non-LBC. This implies that children with higher levels of family function tend to exhibit a lower frequency of NSSI, especially in those with parental migration. In practice, adolescents' NSSI prevention and intervention strategies should focus on improving family function.

Associations of social jetlag and insomnia symptoms with depressive symptoms among Chinese adolescents: A large population-based study.

OBJECTIVE: This study aimed to evaluate the associations of social jetlag and insomnia symptoms with depressive symptoms among adolescents. METHODS: A total of 37,871 junior high students completed an online survey between May 24th and Jun 5th, 2022. Insomnia symptoms were assessed by three items based on the Diagnostic and Statistical Manual of Mental Disorders criteria. Social jetlag and depressive symptoms were evaluated by the Munich Chronotype Questionnaire and the Patient Health Questionnaire, respectively. Restricted cubic splines were used to explore the relationship between social jetlag and depressive symptoms. Joint effects of social jetlag and insomnia symptoms on depressive symptoms were estimated using additive interaction models. RESULTS: The prevalence of depressive symptoms was 13.1%. Depressive symptoms were more common in adolescents with social jetlag ≥2 h (OR: 1.51, 95% CI: 1.39-1.65) and insomnia symptoms (OR: 6.91, 95% CI: 6.41-7.44). There was a J-shaped relationship between social jetlag and depressive symptoms when we took social jetlag as a continuous variable. Moreover, a positive additive interaction of social jetlag ≥2 h and insomnia symptoms on depressive symptoms was found in female adolescents (RERI: 2.30, 95% CI: 0.11-4.49). CONCLUSIONS: Our findings suggested that social jetlag ≥2 h and insomnia are related to the occurrence of depressive symptoms in adolescents. Their coexistence additively enhances the strength of the association with depressive symptoms. Early screening and intervention for insomnia, as well as methods to reduce social jetlag, should be comprised as part of preventive strategies for depression in adolescents.

Loneliness predicts physical and mental health-related quality of life over 9 months among patients with coronary heart disease.

This study investigated whether loneliness would predict physical and mental health-related quality of life (HRQoL) over 9 months and examined whether medical adherence would mediate their associations in patients with coronary heart disease (CHD). The overall design is a three-wave longitudinal study. A sample of 255 outpatients with CHD was recruited from a community-based cardiac rehabilitation programme. Participants, with a mean age of 63 years, completed measures assessing loneliness, depression and physical and mental HRQoL at baseline. Medical adherence was assessed at 3 months, and physical and mental HRQoL were reassessed at 9 months. A total of 88% of participants reported moderate or high loneliness. Baseline loneliness predicted physical and mental HRQoL at 9 months after adjusting for baseline physical and mental HRQoL, respectively. The effects remained significant when depression was also adjusted. Medical adherence at 3 months partially mediated the associations of baseline loneliness with 9-month physical and mental HRQoL. Findings underline the necessity of assessing loneliness for CHD patients to promote long-term medical adherence and further improve physical and mental HRQoL.

Effectiveness of a community-based peer support service among persons suffering severe mental illness in China.

Background: Community-based peer support service is widely and effectively deployed for persons suffering severe mental illness (SMI) in countries with well-developed outpatient mental health systems. The objective of this study is to evaluate the effectiveness of a 1-year peer service project among persons with SMI implemented in China. Methods: A total of 101 consumers (service recipients) and 66 family caregivers were recruited at baseline from communities located in Beijing and Chengdu. Severity of psychiatric symptoms, personal and social functioning, self-esteem, life satisfaction, and medication adherence were evaluated among consumers. Self-esteem, life satisfaction, anxiety, and depressive symptoms were assessed among family caregivers. Participants were reevaluated at 1 year with the same measures. Changes in outcomes from baseline to 1-year follow-up were examined using paired sample t tests or Stuart-Maxwell tests. Results: Consumers' psychiatric symptoms were decreased at 1 year (p < 0.001). Their personal and social functioning (p = 0.003) and life satisfaction (p < 0.001) were increased. There were no improvements in self-esteem (p = 0.108) and medication adherence (ps ≥ 0.827) among consumers. For caregivers, no increases were presented in outcomes at the 1-year assessment (ps ≥ 0.164). Conclusions: The findings suggest that peer support services could be sustainably implemented across China, with positive impacts on the psychiatric symptoms, social functioning, and life satisfaction of participants suffering SMI.

Posttraumatic stress disorder and professional burnout among local government staff seven years after the Wenchuan earthquake in China: A longitudinal study.

Although local government staff are crucial in post-quake reconstruction, their long-term psychological and professional consequences remain unclear. This longitudinal study investigated changes of posttraumatic stress disorder (PTSD) and professional burnout over seven years, and their underlying relationship. The study assessed 250 staff at one year (T1y) after the earthquake, and 162 (64.8 %) were followed up at seven years (T7y). PTSD and professional burnout were assessed with the Short Screening Scale for DSM-IV PTSD and the burnout subscale of Professional Quality of Life Scale (ProQOL), respectively, at both time points. Longitudinal changes in PTSD and burnout were examined and cross-lagged panel analyses were conducted to test the relationship between PTSD and burnout. The rates of positive cases of PTSD screening were 23.2 % at T1y and 11.1 % at T7y. The percentages of moderate burnout were 61.7 % at T1y and 23.5 % at T7y. Scores of PTSD (z = -5.70, p < 0.001) and burnout (t = 10.07, p < 0.001) from T1y to T7y decreased. The cross-lagged analysis indicated that burnout at T1y predicted PTSD at T7y (ß = 0.19, p = 0.025). In conclusion, the Wenchuan earthquake has long-lasting negative effects on local government staff, although they can recover over time. Interventions to reduce professional burnout after disaster may does be beneficial to decrease the risk of PTSD in the long run.

A longitudinal study on emotional distress among local government staff seven years after the 2008 Wenchuan earthquake in China.

BACKGROUND: The current study examined the change in local government staff's emotional distress over 7 years after the 2008 Wenchuan earthquake, and the influence of earthquake exposure and professional quality of life (ProQOL) on emotional distress. METHODS: This longitudinal study assessed 250 participants at 1 year after the earthquake; 162 (64.8%) were followed up at 7 years. Emotional distress was assessed with the Self-Reporting Questionnaire (SRQ) at both time points. We assessed ProQOL, including compassion satisfaction, burnout, and secondary traumatic stress, and earthquake exposure at 1 year. Wilcoxon signed-rank tests were performed to test longitudinal changes in emotional distress. Hierarchical multiple regression was conducted to examine the effect of earthquake exposure and ProQOL. RESULTS: The positive screening rate of emotional distress (SRQ ≥ 8) was 37.6 and 15.4% at one and 7 years, respectively. Emotional distress scores declined over time (p < 0.001). Earthquake exposure and ProQOL predicted one-year (ps < 0.05) but not seven-year emotional distress, whereas burnout predicted both one-year (p = 0.018) and seven-year (p = 0.047) emotional distress. CONCLUSIONS: Although emotional distress can recover over time, it persists even 7 years later. Actions to reduce burnout during the early stage of post-disaster rescue have long-term benefits to staff's psychological outcomes.

Depression, anxiety, perceived stress, and their changes predicted medical adherence over 9 months among patients with coronary heart disease.

OBJECTIVES: Although effective medical treatments have proved to successfully improve prognoses and outcomes of patients with coronary heart disease (CHD), low adherence to treatments is still common among patients. Deleterious impact of psychological distress on medical adherence has been recognized; however, few studies examined the influence of change in psychological distress on attenuation in adherence. This study investigated whether three common manifestations of distress (depression, anxiety, and perceived stress) and their changes predicted decline in medical adherence among CHD patient over 9 months. DESIGN: A three-wave longitudinal study. METHODS: Participants were 255 CHD patients with a mean age of 63 years. Psychological distress, medication adherence, and specific treatment adherence were assessed at baseline, 3 months, and 9 months. Hierarchical regression analyses were conducted to examine the influences of psychological distress on medical adherence over 9 months. All models were adjusted for baseline medication or specific adherence, demographic, and medical covariates. RESULTS: Baseline depression and its changes over time significantly predicted greater decline in both medication adherence (ßs = .15-.20, ps < .05) and specific adherence (ßs = -.21 to -.15, ps < .05). Anxiety showed a similar trend. For perceived stress, baseline and its change significantly predicted specific adherence over 9 months (ßs = -.30 to -.23, ps < .01), but did not predict medication adherence at 3 and 9 months. CONCLUSIONS: Findings underline the necessity of tracking various forms of psychological distress over time for CHD patients to promote medical adherence and further improve the disease prognosis.

Feasibility of peer support services among people with severe mental illness in China.

BACKGROUND: Peer-delivered services potentially provide broad, multifaceted benefits for persons suffering severe mental illness. Most studies to date have been conducted in countries with well-developed outpatient mental health systems. The objective of this study was to examine the feasibility for developing a community-based peer service in China. METHODS: Thirteen peer service providers and 54 consumers were recruited from four communities in Beijing. We initiated the program in two communities, followed by another two in order to verify and add to our understanding of potential scalable feasibility. Semi-structured face-to-face interviews were conducted 12 month after initiation at each site to measure satisfaction and perceived benefits from perspectives of peer service providers, and consumers and their caregivers. RESULTS: Key stakeholders reported that peer support services were satisfying and beneficial. Eleven of 13 peer service providers were willing to continue in their roles. Ten, 8, and 7 of them perceived improvements in working skills, social communication skills, and mood, respectively. Among consumers, 39 of 54 were satisfied with peer services. Improvements in mood, social communication skills, illness knowledge, and illness stability were detected among 23, 18, 13, and 13 consumers, respectively. For caregivers, 31 of 32 expressed a positive view regarding peer services. Caregivers reported improvement in their own mood, confidence in recovery of their family members, and reduction in caretaker burdens. CONCLUSIONS: The findings highlight that peer-delivered services have promise in China for benefiting persons with severe mental illness and their family caregivers, as well as the peer service providers themselves.

Depression, Anxiety, Perceived Stress, and Their Changes Predict Greater Decline in Physical Health Functioning over 12 Months Among Patients with Coronary Heart Disease.

BACKGROUND: Although the deleterious impact of psychological distress on patients with coronary heart disease (CHD) is recognized, few studies have examined the influence of change in psychological distress on health outcomes over time. This study investigated whether three common manifestations of distress (depression, anxiety, and perceived stress) and their changes predicted the decline in physical functioning in CHD patients over 12 months. In addition, perceived social support was examined as a buffer of psychological distress or a direct predictor of physical functioning. METHODS: Participants were 255 CHD patients with a mean age of 63 (SD = 8.65) years, including 208 men and 47 women. Psychological distress and physical functioning were assessed at baseline, 6 months and 12 months. Hierarchical regression analyses were conducted to examine the influences of psychological factors on physical functioning over 12 months. All models were adjusted for baseline physical functioning, age, gender, marital status, education, BMI, and length of participation at a wellness center. RESULTS: For each psychological distress variable (depression, anxiety, or perceived stress), both the baseline (ßs = - 0.19 to - 0.32, ps = 0.008 to < 0.001) and its respective change over time (ßs = - 0.17 to - 0.38, ps = 0.020 to < 0.001) independently and significantly predicted greater decline in physical functioning at 6 and 12 months, after adjusting for covariates. Perceived social support predicted greater improvement in physical functioning at 12 months (ß = 0.13, p = 0.050), but it did not buffer impact of psychological distress. CONCLUSIONS: Findings underscore the importance of monitoring various forms of psychological distress continuously over time for CHD patients.

A community-based peer support service for persons with severe mental illness in China.

BACKGROUND: Peer support services for patients with severe mental illness (SMI) originated from Western countries and have become increasingly popular during the past twenty years. The aim of this paper is to describe a peer service model and its implementation in China, including the model's feasibility and sustainability. METHODS: A peer support service was developed in four Chinese communities. Implementation, feasibility and sustainability were assessed across five domains: Service process, service contents, peer training and supervision, service satisfaction, and service perceived benefit. RESULTS: Service process: 214 peer support activities were held between July 2013 and June 2016. No adverse events occurred during three years. Each activity ranged from 40 to 120 min; most were conducted in a community rehabilitation center or community health care center. Service content: Activities focused on eight primary topics-daily life skills, social skills, knowledge of mental disorders, entertainment, fine motor skill practice, personal perceptions, healthy life style support, emotional support. Peer training and supervision: Intensive training was provided for all peers before they started to provide services. Regular supervision and continued training were provided thereafter; online supervision supplemented face to face meetings. Service satisfaction: Nineteen consumers (79.2%) (χ2(1) = 12.76, p < 0.001) were satisfied with the peers and 17 consumers (70.8%) (χ2(1) = 8.05, p = 0.005) expressed a strong desire to continue to participate in the service. Fourteen caregivers (93.3%) (χ2(1) = 11.27, p = 0.001) wanted the patients to continue to organize or participate in the service. Service perceived benefit: Six peers (85.7%) (χ2(1) = 3.57, p = 0.059) reported an improvement of working skills. Ten consumers (41.7%) (χ2(1) = 0.05, p = 0.827) reported better social communication skills. Six caregivers (40%) (χ2(1) = 1.67, p = 0.197) observed patients' increase in social communication skills, five (33.3%) (χ2(1) = 1.67, p = 0.197) found their own mood had been improved. CONCLUSIONS: Peer support services for patients with SMI can be sustainably implemented within Chinese communities without adverse events that jeopardize safety and patient stability. Suggestions for future service development include having professionals give increased levels of support to peers at the beginning of a new program. A culturally consistent peer service manual, including peer role definition, peer training curriculum, and supervision methods, should be developed to help implement the service smoothly.

Layer-by-layer supramolecular assemblies based on linear and star-shaped poly(glycerol methacrylate)s for doxorubicin delivery.

Hollow microcapsules, composed of pH responsive polyelectrolytes via a layer-by-layer (LBL) adsorption technique, were prepared. Linear or star-shaped poly(glycerol metha crylate)s (PGOHMAs) modified with 1,4-butanediamine and 1,2-ethanediamine (EDA) were synthesized and used as polycations. Poly(acrylic acid) was employed as polyanion and SiO2 (about 170 nm) as template. After LBL absorption, SiO2 cores were removed by HF treatment. The particle size and zeta potential were measured by dynamic light scattering, showing that the diameter of star-shaped amino-PGOHMA was larger than linear counterpart. The LBL assembly and core-etching process were evidenced by scanning electron microscope, transmission electron microscope, and energy dispersive spectrometer. The cytotoxicity experiments on human umbilical vein endothelial cells were carried out to evaluate the toxicity of LBL assembly. The star-shaped and EDA-modified PGOHMA exhibited better cell viability. The microcapsules were then used to load an anticancer drug, doxorubicin hydrochloride. High loading capacity (about 42%) and entrapment efficiency (84%) were obtained for star-shaped polymer-based microcapsules. The cumulative release rate was evaluated in vitro, showing faster release at an acidic condition compared to neutral pH. Confocal laser scanning microscopy evidenced the successful cellular uptake of DOX-loaded microparticles.

Temperature- and pH-responsive nanoparticles of biocompatible polyurethanes for doxorubicin delivery.

A series of temperature- and pH-responsive polyurethanes based on hexamethylene diisocyanate (HDI) and 4,4'-diphenylmethane diisocyanate (MDI) were synthesized by a coupling reaction with bis-1,4-(hydroxyethyl) piperazine (HEP), N-methyldiethanolamine (MDEA) and N-butyldiethanolamine (BDEA), respectively. The chemical structure, molecular weight, thermal property and crystallization properties were characterized by Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) spectroscopy. The resulting polyurethanes were then used to prepare nanoparticles either by direct dispersion method or dialysis method. Their pH and temperature responsibilities were evaluated by optical transmittance and size measurement in aqueous media. Interestingly, HDI-based and MDI-based polyurethanes exhibited different pH and temperature responsive properties. Nanoparticles based on HDI-HEP and HDI-MDEA were temperature-responsive, while MDI-based biomaterials were not. All of them showed pH-sensitive behavior. The possible responsive mechanism was investigated by (1)H NMR spectroscopy. The cytotoxicity of the polyurethanes was evaluated using methylthiazoletetrazolium (MTT) assay in vitro. It was shown that the HDI-based polyurethanes were non-toxic, and could be applied to doxorubicin (DOX) encapsulation. The experimental results indicated that DOX could be efficiently encapsulated into polyurethane nanoparticles and uptaken by Huh-7 cells. The loaded DOX molecules could be released from the drug-loaded polyurethane nanoparticles upon pH and temperature changes, responsively.

Enhanced adsorption of puerarin onto a novel hydrophilic and polar modified post-crosslinked resin from aqueous solution.

A novel of hydrophilic and polar N-vinylpyrrolidone modified post-crosslinked resin was synthesized and the adsorption behaviors toward puerarin from aqueous solution were investigated. The post-crosslinked adsorbent PNVP-DVBpc was prepared by Friedel-Crafts reaction of residual double bonds without external crosslinking agent. The specific surface area of precursor PNVP-DVB increased obviously after post-crosslinking modification. The synthesized adsorbents were characterized by BET surface area, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM). The adsorption behaviors of puerarin from aqueous solution onto precursor PNVP-DVB and post-crosslinked adsorbent PNVP-DVBpc were thoroughly researched. Commercial polymeric adsorbents Amberlite XAD-4 and AB-8 were chosen as the comparison. Among the four media, PNVP-DVBpc presented the largest adsorption capacity of puerarin, which resulted from the synergistic effect of high specific surface area and polar groups (amide groups) onto the adsorbent matrix. Experimental results showed that equilibrium isotherms could be fitted by Freundlich model and the kinetic data could be characterized by pseudo-second order model reasonably. Column adsorption experiments indicated that the puerarin could be completely desorbed by 4.0 BV industrial alcohol. Continuous column adsorption-regeneration cycles demonstrated the PNVP-DVBpc without any significant adsorption capacity loss during operation.