Parental Psychological Control and Risk-Taking among Taiwanese Adolescents and Emerging Adults: Benefit Perception as a Mediator.

Youth risk-taking behaviors present important public health concerns due to their prevalence and potential adverse consequences, underscoring the need for research and prevention strategies to promote youth's healthy development. The present research examined the relationship between parental psychological control and risk-taking behaviors via benefit perception among high school and college students in Taiwan. Using a cross-sectional design, the study surveyed 378 participants to assess maternal and paternal psychological control, benefit perception, and engagement in risk-taking behaviors. Results indicated no significant difference in psychological control or benefit perception between high school and college students. However, college students reported higher levels of risk-taking behaviors, such as risky driving, alcohol use, and unprotected sex. Both maternal and paternal psychological control positively correlated with benefit perception and risk-taking behaviors. Furthermore, benefit perception mediated the relationship between psychological control and risk-taking behavior among high school and college students. These findings suggested that parental psychological control indirectly influenced youth risk-taking by shaping their perceptions of the benefits of such behaviors. The study highlights the importance of promoting autonomy-supportive parenting to reduce risk-taking behaviors and advocates for programs that enhance decision-making skills among adolescents and emerging adults.

The association of dysfunctional beliefs about sleep with vulnerability to stress-related sleep disturbance in young adults.

This study aims to explore the association between dysfunctional sleep beliefs and vulnerability to stress-related transient sleep disturbance in people without sleep disturbance. One hundred thirty-two good sleepers and 307 poor sleepers were included in this study. As expected, poor sleepers showed more dysfunctional beliefs than good sleepers on the Dysfunctional Beliefs and Attitudes about Sleep scale-10 item version (DBAS-10). More important, even in good sleepers, DBAS-10 scores positively correlated with the vulnerability to stress-related sleep disturbance as measured by the Ford Insomnia Response to Stress Test. The results suggest that dysfunctional sleep belief is not only a perpetuating factor for chronic insomnia, it may also serve as a risk factor for stress-related transient insomnia.

Heparin-mediated delivery of bone morphogenetic protein-2 improves spatial localization of bone regeneration.

Supraphysiologic doses of bone morphogenetic protein-2 (BMP-2) are used clinically to promote bone formation in fracture nonunions, large bone defects, and spinal fusion. However, abnormal bone formation (i.e., heterotopic ossification) caused by rapid BMP-2 release from conventional collagen sponge scaffolds is a serious complication. We leveraged the strong affinity interactions between heparin microparticles (HMPs) and BMP-2 to improve protein delivery to bone defects. We first developed a computational model to investigate BMP-2-HMP interactions and demonstrated improved in vivo BMP-2 retention using HMPs. We then evaluated BMP-2-loaded HMPs as a treatment strategy for healing critically sized femoral defects in a rat model that displays heterotopic ossification with clinical BMP-2 doses (0.12 mg/kg body weight). HMPs increased BMP-2 retention in vivo, improving spatial localization of bone formation in large bone defects and reducing heterotopic ossification. Thus, HMPs provide a promising opportunity to improve the safety profile of scaffold-based BMP-2 delivery.

Enhanced in vivo retention of low dose BMP-2 via heparin microparticle delivery does not accelerate bone healing in a critically sized femoral defect.

Bone morphogenetic protein-2 (BMP-2) is an osteoinductive growth factor used clinically to induce bone regeneration and fusion. Some complications associated with BMP-2 treatment have been attributed to rapid release of BMP-2 from conventional collagen scaffolds, motivating the development of tunable sustained-release strategies. We incorporated BMP-2-binding heparin microparticles (HMPs) into a hydrogel scaffold to improve spatiotemporal control of BMP-2 delivery to large bone defects. HMPs pre-loaded with BMP-2 were mixed into alginate hydrogels and compared to hydrogels containing BMP-2 alone. BMP-2 release from scaffolds in vitro, BMP-2 retention within injury sites in vivo, and bone regeneration in a critically sized femoral defect were evaluated. Compared to hydrogel delivery alone, BMP-2-loaded HMPs reduced BMP-2 release in vitro and increased early BMP-2 retention in the bone defect. BMP-2-loaded HMPs induced bone formation at both ectopic and orthotopic sites; however, the volume of induced bone was lower for defects treated with BMP-2-loaded HMPs compared to hydrogel delivery. To better understand the effect of HMPs on BMP-2 release kinetics, a computational model was developed to predict BMP-2 release from constructs in vivo. The model suggested that HMPs limited BMP-2 release into surrounding tissues, and that changing the HMP density could modulate BMP-2 release. Taken together, these experimental and computational results suggest the importance of achieving a balance of BMP-2 retention within the bone defect and BMP-2 release into surrounding soft tissues. HMP delivery of BMP-2 may provide a method of tuning BMP-2 release in vivo that can be further investigated to improve current methods of bone regeneration. STATEMENT OF SIGNIFICANCE: The development of effective biomaterials for sustained protein delivery is a crucial component of tissue engineering strategies. However, in most applications, including bone repair, the optimal balance between protein presentation in the injury site and protein release into the surrounding tissues is unknown. Herein, we introduced heparin microparticles (HMPs) into a tissue engineered construct to increase in vivo retention of bone morphogenetic protein-2 (BMP-2) and enhance healing in femoral defects. Although HMPs induced bone regeneration, no increase in bone volume was observed, leading to further experimental and computational analysis of the effect of HMP-BMP-2 interactions on protein retention and release. Ultimately, this work provides insight into designing tunable protein-material interactions and their implications for controlling BMP-2 delivery.

Competitive Protein Binding Influences Heparin-Based Modulation of Spatial Growth Factor Delivery for Bone Regeneration.

Tissue engineering strategies involving the in vivo delivery of recombinant growth factors are often limited by the inability of biomaterials to spatially control diffusion of the delivered protein within the site of interest. The poor spatiotemporal control provided by porous collagen sponges, which are used for the clinical delivery of bone morphogenetic protein-2 (BMP-2) for bone regeneration, has necessitated the use of supraphysiological protein doses, leading to inflammation and heterotopic ossification. This study describes a novel tissue engineering strategy to spatially control rapid BMP-2 diffusion from collagen sponges in vivo by creating a high-affinity BMP-2 sink around the collagen sponge. We designed an electrospun poly-ɛ-caprolactone nanofiber mesh containing physically entrapped heparin microparticles, which have been previously demonstrated to bind and retain large amounts of BMP-2. Nanofiber meshes containing 0.05 and 0.10 mg of microparticles/cm2 demonstrated increased BMP-2 binding and decreased BMP-2 release in vitro compared with meshes without microparticles. However, when microparticle-containing meshes were used in vivo to limit the diffusion of BMP-2 delivered by using collagen sponges in a rat femoral defect, no differences in heterotopic ossification or biomechanical properties were observed. Further investigation revealed that, although BMP-2 binding to heparin microparticles was rapid, the presence of serum components attenuated microparticle-BMP-2 binding and increased BMP-2 release in vitro. These observations provide a plausible explanation for the results observed in vivo and suggest that competitive protein binding in vivo may hinder the ability of affinity-based biomaterials to modulate growth factor delivery.