Novel hydrogel system eliminates subculturing and improves retention of nonsenescent mesenchymal stem cell populations

Aim: To compare the physiological behavior of mesenchymal stem/stromal cells (MSCs) within an expandable tissue-mimetic 3D system relative to in vitro expansion in a traditional 2D system. Methods: Adipose-derived MSCs (ASCs) were continuously cultured for 6 weeks on either 2D culture plastic or in a 3D hydrogel system that eliminated subculturing. ASCs were assessed for senescence, ‘stem-like’ MSC markers, and ability for their secretome to augment a secondary cell population. Results: The 3D hydrogel system resulted in an enhanced retention of more regenerative, nonsenescent ASC populations that exhibited increased expression of ‘stem-like’ MSC surface markers. Conclusion: This study introduces a proof-of-concept design for a novel modular 3D system that can improve in vitro expansion of stem-like cell populations for future regenerative therapies

Tailoring the secretome composition of mesenchymal stem cells to augment specific functions of epidermal regeneration: an in vitro diabetic model

Introduction: Wound healing consists of a dynamic series of events that are highly dependent on paracrine factors for proper progression through the phases of wound healing. Inappropriate progression through the phases is associated with insufficient epidermal regeneration (i.e., re-epithelialization) of wounds and subsequent propagation of chronic wounds, such as diabetic ulcers, which are associated with increased patient morbidity. Recently, investigation into the dynamic secretome of Adipose-derived Mesenchymal Stem Cells (ASCs), have shown promise in augmenting the wound healing response of chronic diabetic wounds. However, currently utilized 2D culture techniques are known to drastically alter the regenerative phenotype of ASCs. In this study a novel tissue-mimetic 3D system was utilized as a means to culture ASCs. Methods: The capacity for the ASC secretome to augment epidermal regeneration activity was then evaluated after exposure of ASCs to “wound priming stimuli” in 2D and 3D. The priming stimuli consisted of coating the 2D and 3D systems with the wound matrix proteins, collagen type I, fibronectin, and fibrin. To understand the potential benefit of the ASC secretome in the context of diabetic wounds, keratinocytes (KCs) were exposed to super-physiological glucose levels to induce a diabetic-like phenotype (idKCs). Results: Relative to KCs, idKC exhibited a 52% and 23% decline in proliferation and migration, respectively. Subsequently, analyses of the ASC secretome were performed. ASC conditioned media (ASC-CM) from tissue-mimetic culture demonstrated a > 50% increase secretion of proteins and a 2-fold increase in secreted EVs, relative to 2D culture. Interestingly, the different priming stimuli did not alter the total amount of protein or EVs secreted within the tissue-mimetic system. However, evaluation of specific soluble proteins via ELISA revealed significant differences in key epidermal regeneration factors, such as EGF, IGF-1, FGF-2, MMP-1, TIMP-1, and TGFβ-1. Additionally, the relative effect of ASC-EVs from the 2D and 3D system on idKCs epidermal regeneration functionality varied significantly, with EVs from 3D-Collagen culture providing the most significant benefit on idKC activity. Discussion: Together, these data support the utilization of tissue-mimetic culture system to enhance the adaptability and secretory activity of MSC-like populations in order to generate tailored biologics, via priming stimuli, for specific wound healing applications

Successful treatment of noise-induced hearing loss by mesenchymal stromal cells: An RNAseq analysis of protective/repair pathways

Mesenchymal stromal cells (MSCs) are an adult derived stem cell-like population that has been shown to mediate repair in a wide range of degenerative disorders. The protective effects of MSCs are mainly mediated by the release of growth factors and cytokines thereby modulating the diseased environment and the immune system. Within the inner ear, MSCs have been shown protective against tissue damage induced by sound and a variety of ototoxins. To better understand the mechanism of action of MSCs in the inner ear, mice were exposed to narrow band noise. After exposure, MSCs derived from human umbilical cord Wharton\u27s jelly were injected into the perilymph. Controls consisted of mice exposed to sound trauma only. Forty-eight hours post-cell delivery, total RNA was extracted from the cochlea and RNAseq performed to evaluate the gene expression induced by the cell therapy. Changes in gene expression were grouped together based on gene ontology classification. A separate cohort of animals was treated in a similar fashion and allowed to survive for 2 weeks post-cell therapy and hearing outcomes determined. Treatment with MSCs after severe sound trauma induced a moderate hearing protective effect. MSC treatment resulted in an up-regulation of genes related to immune modulation, hypoxia response, mitochondrial function and regulation of apoptosis. There was a down-regulation of genes related to synaptic remodeling, calcium homeostasis and the extracellular matrix. Application of MSCs may provide a novel approach to treating sound trauma induced hearing loss and may aid in the identification of novel strategies to protect hearing

Reduced hypoglycemia risk in type 2 diabetes patients switched to/initiating insulin glargine 300 vs 100 U/ml: A european real-world study

Introduction: Randomized controlled trials and real-world data from the USA have shown similar glycemic control with insulin glargine 300 U/ml (Gla-300) and insulin glargine 100 U/ml (Gla-100) and reduced hypoglycemia risk with Gla-300. This real-world study describes the efficacy and safety of Gla-300 and Gla-100 in patients with type 2 diabetes (T2D) in France, Spain, and Germany. Methods: This retrospective chart review analysis used anonymized data for adults with T2D switching basal insulin analog (BIA) therapy to Gla-300 or Gla-100, or insulin-naïve patients initiating Gla-300 or Gla-100. Outcomes included change from baseline to 6-month follow-up in glycated hemoglobin A1c (A1C), total and severe hypoglycemia incidences and events, insulin dose, and reasons for BIA choice. Results: Six hundred sixty-five physicians (33.8% Spain, 31.7% France, 34.4% Germany) provided chart data for patients switching to Gla-300 (n = 679) or Gla-100 (n = 429) or initiating Gla-300 (n = 719) or Gla-100 (n = 711). After adjustment for baseline characteristics, A1C reductions from baseline were similar for patients switching to Gla-300 or Gla-100 (- 0.87% vs. - 0.93%; p = 0.326) while those switched to Gla-300 vs. Gla-100 had a significantly greater mean reduction in hypoglycemic events (- 1.29 vs. - 0.81 events during 6 months; p = 0.012). Mean insulin doses after titration were 0.43 ± 0.36 and 0.40 ± 0.28 U/kg in Gla-300 and Gla-100 switchers, respectively. Factors that significantly influenced BIA choice included a lower risk of hypoglycemia (for Gla-300) and physician familiarity (for Gla-100). Outcomes for insulin-naïve patients were broadly similar to those of switchers. Conclusions: In this real-world European study, patients with T2D who switched therapy to Gla-300 or Gla-100 had improved glycemic control and reduced hypoglycemia at 6 months, with significant hypoglycemia advantages with Gla-300

Adult patient preferences for long-acting ADHD treatments: A discrete choice experiment

Background and Objective: Treatment for attention deficit hyperactivity disorder (ADHD) requires a multifaceted approach including psychosocial interventions and pharmacological treatment. This study evaluates preferences for specific attributes associated with different long-acting stimulant treatment among US adults with ADHD. Methods: Patients completed an online, cross-sectional survey, incorporating a discrete choice experiment to assess preferences for attributes. Results: Analyses included 200 adults with ADHD (mean age 33.0 years; 60% self-reporting moderate severity); the mean (SD) Adult ADHD Self-Report Scale-v1.1 score was 45.9 (12.4). Overall, patients valued speed of onset most and risk of rebound least. Three population groups with distinct preferences were identified: side effect-driven (n=69, 35%), quick onset-driven (n=47, 24%) and quick onset and long duration-driven (n=84, 42%). Conclusion: This study shows differences in how adults with ADHD value and assess benefit-risk trade-offs when considering the desired attributes of stimulant treatments, highlighting the importance of patient-physician shared decision-making to optimize the desired benefits of individualized treatment

Force Characterization and Manufacturing of a Dynamic Unilateral Clubfoot Brace

Clubfoot is a musculoskeletal birth defect that is characterized by an inward twisting of an infant’s feet. The current method for correction involves several casts and a bilateral boots-and-bar maintenance brace. This method of maintenance requires 5 years of bracing and has issues with compliance, comfort, and social stigma. CURE International in Kijabe, Kenya is currently using the boots-and-bar brace but is interested in implementing a design that reduces these concerns. Mr. Jerald Cunningham, CPO, designed and is utilizing a unilateral clubfoot maintenance brace, the Cunningham Brace, which he expects will reduce treatment time to 2-3 years, lessen the social stigma, and increase the child’s mobility. However, there is not enough published research on its biomechanics and patient success rates to confirm his findings. The Collaboratory Cunningham Clubfoot Brace project seeks to validate the effectiveness of this design and increase accessibility through force testing and standardized manufacturing. We are working on measuring the biomechanical forces created and applied by the brace with a series of force sensors that are attached to the child’s brace. In addition, a new wrapping process for manufacturing the Cunningham Brace is being developed to increase the productivity and reproducibility of brace manufacturing in Kenya. Along with a clinical study that was started in Kenya, this testing and manufacturing will allow for further understanding of the effectiveness of the Cunningham Brace and provide more research for the medical community for it to potentially be accepted as an alternative clubfoot maintenance brace.https://mosaic.messiah.edu/engr2020/1014/thumbnail.jp

Investigation of human adipose-derived stem-cell behavior using a cell-instructive polydopamine-coated gelatin-alginate hydrogel.

Hydrogels can be fabricated and designed to exert direct control over stem cells\u27 adhesion and differentiation. In this study, we have investigated the use of polydopamine (pDA)-treatment as a binding platform for bioactive compounds to create a versatile gelatin-alginate (Gel-Alg) hydrogel for tissue engineering applications. Precisely, pDA was used to modify the surface properties of the hydrogel and better control the adhesion and osteogenic differentiation of human adipose-derived stem cells (hASCs). pDA enabled the adsorption of different types of bioactive molecules, including a model osteoinductive drug (dexamethasone) as well as a model pro-angiogenic peptide (QK). The pDA treatment efficiently retained the drug and the peptide compared to the untreated hydrogel and proved to be effective in controlling the morphology, cell area, and osteogenic differentiation of hASCs. Overall, the findings of this study confirm the efficacy of pDA treatment as a valuable strategy to modulate the biological properties of biocompatible Gel-Alg hydrogels and further extend their value in regenerative medicine

Dependence of CMI Growth Rates on Electron Velocity Distributions and Perturbation by Solitary Waves

We calculate growth rates and corresponding gains for RX and LO mode radiation associated with the cyclotron maser instability for parameterized horseshoe electron velocity distributions. The velocity distribution function was modeled to closely fit the electron distribution functions observed in the auroral cavity. We systematically varied the model parameters as well as the propagation direction to study the dependence of growth rates on model parameters. The growth rate depends strongly on loss cone opening angle, which must be less than $90^{o}$ for significant CMI growth. The growth rate is sharply peaked for perpendicular radiation ($k_{\parallel} = 0$), with a full-width at half-maximum $1.7^{o}$, in good agreement with observed k-vector orientations and numerical simulations. The fractional bandwidth varied between 10$^{-4}$ and 10$^{-2}$, depending most strongly on propagation direction. This range encompasses nearly all observed fractional AKR burst bandwidths. We find excellent agreement between the computed RX mode emergent intensities and observed AKR intensities assuming convective growth length $L_c\approx$20-40 km and group speed 0.15$c$. The only computed LO mode growth rates compatible observed LO mode radiation levels occurred for number densities more than 100 times the average energetic electron densities measured in auroral cavities. This implies that LO mode radiation is not produced directly by the CMI mechanism but more likely results from mode conversion of RX mode radiation. We find that perturbation of the model velocity distribution by large ion solitary waves (ion holes) can enhance the growth rate by a factor of 2-4. This will result in a gain enhancement more than 40 dB depending on the convective growth length within the structure. Similar enhancements may be caused by EMIC waves.Comment: 21 pages, 11 figures. J. Geophys. Res. 2007 (accepted

Age-related upregulation of dense core vesicles in the central inferior colliculus

Presbycusis is one of the most prevalent disabilities in aged populations of industrialized countries. As we age less excitation reaches the central auditory system from the periphery. To compensate, the central auditory system [e.g., the inferior colliculus (IC)], downregulates GABAergic inhibition to maintain homeostatic balance. However, the continued downregulation of GABA in the IC causes a disruption in temporal precision related to presbycusis. Many studies of age-related changes to neurotransmission in the IC have therefore focused on GABAergic systems. However, we have discovered that dense core vesicles (DCVs) are significantly upregulated with age in the IC. DCVs can carry neuropeptides, co-transmitters, neurotrophic factors, and proteins destined for the presynaptic zone to participate in synaptogenesis. We used immuno transmission electron microscopy across four age groups (3-month; 19-month; 24-month; and 28-month) of Fisher Brown Norway rats to examine the ultrastructure of DCVs in the IC. Tissue was stained post-embedding for GABA immunoreactivity. DCVs were characterized by diameter and by the neurochemical profile (GABAergic/non-GABAergic) of their location (bouton, axon, soma, and dendrite). Our data was collected across the dorsolateral to ventromedial axis of the central IC. After quantification, we had three primary findings. First, the age-related increase of DCVs occurred most robustly in non-GABAergic dendrites in the middle and low frequency regions of the central IC during middle age. Second, the likelihood of a bouton having more than one DCV increased with age. Lastly, although there was an age-related loss of terminals throughout the IC, the proportion of terminals that contained at least one DCV did not decline. We interpret this finding to mean that terminals carrying proteins packaged in DCVs are spared with age. Several recent studies have demonstrated a role for neuropeptides in the IC in defining cell types and regulating inhibitory and excitatory neurotransmission. Given the age-related increase of DCVs in the IC, it will be critical that future studies determine whether (1) specific neuropeptides are altered with age in the IC and (2) if these neuropeptides contribute to the loss of inhibition and/or increase of excitability that occurs during presbycusis and tinnitus

Multiple Lines of Evidence Risk Assessment of Terrestrial Passerines Exposed to PCDFs and PCDDs in the Tittabawassee River Floodplain, Midland, Michigan, USA

A site-specific multiple lines of evidence risk assessment was conducted for house wrens (Troglodytes aedon) and eastern bluebirds (Sialia sialis) along the Tittabawassee River downstream of Midland, Michigan, where concentrations of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzo-p-dioxins (PCDDs) in flood-plain soils and sediments are greater compared to upstream areas and some of the greatest anywhere in the world. Lines of evidence supporting the population-level assessment endpoints included site-specific dietary- and tissue-based exposure assessments and population productivity measurements during breeding seasons 2005–2007. While a hazard assessment based on site-specific diets suggested that populations residing in the downstream floodplain had the potential to be affected, concentrations in eggs compared to appropriate toxicity reference values (TRVs) did not predict a potential for population-level effects. There were no significant effects on reproductive success of either species. The most probable cause of the apparent difference between the dietary- and tissue-based exposure assessments was that the dietary-based TRVs were overly conservative based on intraperitoneal injections in the ring-necked pheasant. Agreement between the risk assessment based on concentrations of PCDFs and PCDDs in eggs and reproductive performance in both species supports the conclusion of a small potential for population-level effects at this site