Osteoarthritis (OA) is one of the most significant health problems of today’s time. Three  dimensional culture models area major tool used by researchers to study cartilage degeneration associated with OA. The objective was to improve upon current 3D culture models. The hypothesis was that atelocollagen, when added to a hyaluronan matrix, enhances the chondrogenic development of bone-marrow derived mesenchymal stem cells (MSC). Additionally, these 3D cultures can be used to model inflammation-induced cartilage degradation. The experiment was organized into two phases. Phase I focused on the development of cartilage through the 3D culture of MSCs and Phase II, focused on the inflammation-induced degradation of the cultures. Conditioned mediums from naive and inflamed macrophages were added to the cultures after development and they were eventually processed for the purposes of histology and gene expression analysis. During Phase I, atelocollagen added to the hyaluronan matrix, significantly increased the gene expression of COLL II and decreased that of MMP13 when compared to hyaluronan alone, indicating improved matrix formation. This was reflected in histological analyses, as both the change in interstitial matrix and territorial matrix grade were greater in the cultures with atelocollagen. After inflammation exposure, there was a significant decrease in COLLII expression with a concomitant increase in MMP13 expression in both cultures indicating inflammation-induced degradation. Therefore, this new model of developing cartilage from MSC with hyaluronan and atelocollagen creates an articular cartilage model that acts like real cartilage in both healthy and damaged states.

Over the past decade, there have been many significant advances in the field of skin aging, including studies that explore the clearance of senescent (growth-arrested) cells in skin, regenerative therapeutics, and even 3D bioprinting of skin. One of the latest discoveries showed that blocking Interleukin 17 (IL-17) signaling leads to delays in the skin aging process. But how does IL-17, a pro-inflammatory cytokine, delay what has been known as the inevitable hallmarks of skin aging? 

When it comes to the medical field, 3D modeling has previously been used to render anatomical images in greater detail in order to better understand bodily functions. Lately, however, 3D modeling has made waves in depicting diseases, with a focus on their severity and progression. Unlike a model depicting computer graphics, 3D culture models allow cells to interact in three dimensions and better display cell growth and movement, according to the Food and Drug Administration. Culture models are beneficial in replicating the complexities of disease by promoting interactions between cells and providing insight into potential solutions. In this issue of the Journal of Young Investigators, Priscilla Detwieler and her colleagues demonstrate that atelocollagen incorporated in a 3D model is shown to simulate a potential treatment for inflammation-induced osteoarthritis.  

Nurses are at risk of poor sleep health and may be an important target population for sleep interventions. However, little is known about the factors predicting preferences for different sleep intervention types or deliveries. This current study examined the relationship between diverse factors (e.g., sociodemographics, sleep hygiene knowledge, personality) and preferences for various sleep interventions. The data was collected from 86 outpatient nurses. Participants provided their sociodemographic information and completed questionnaires assessing their personality traits, sleep hygiene knowledge and preferences for sleep intervention types and deliveries. Nearly all participants were interested in participating in a sleep intervention (99%). The preferred sleep intervention type among respondents was mindfulness-based training (74%), while an online format (88%) was the most favored delivery method. Those with lower incomes and lower agreeableness were associated with endorsing sleep hygiene education more frequently. Nurses who had more than one child, provided sleep hygiene tips to patients, and demonstrated higher levels of openness and agency were inclined to endorse mindfulness-based training. For sleep intervention delivery, nurses who worked longer hours and nurses who did not provide sleep hygiene tips to patients favored group meetings more highly. Being White Hispanic or a person of color was associated with a higher endorsement of one-on-one meetings. Finally, nurses of a younger age and being a single child parent were associated with a higher endorsement for an online format delivery of sleep interventions. Findings from this study may help inform the planning, recruitment, and implementation of future interventions aimed to improve sleep health in nurses, and further, in other vulnerable healthcare workers.

The Engineered Cementitious Composite (ECC) model has found that ≤ 2% by volume of discontinuous fiber is favorable for strain-hardening behavior and enhanced ductility in commercial concrete. Using this model, we attempted to mechanically optimize injectable calcium phosphate bone grafts via fiber reinforcement of cellulose nanocrystals (CNC) and gelatin polymer fibers. Results displayed significant decreases in the bone grafts’ hardness after the 1–2% CNC critical point (p < 0.001) due to fibril agglomeration, which likely prompted internal cracking and lowered the samples’ tolerance for plastic deformation. In support, Fourier transform infrared (FTIR) spectroscopy displayed decreased levels of cellulose-gelatin hydrogen bonding after this critical point due to decreases in transmittance broadening. Scanning electron microscopy (SEM) also showed that low-fiber CNC samples exhibited extensive microcracking compared to higher-fiber CNC samples, which contained larger cracks and fiber aggregates, indicating catastrophic failure and reduced hydrogen bonding between cellulose and gelatin.