Practitioner Burnout and Productivity Levels in Skilled Nursing and Assisted Living Facilities, Part 1: A Descriptive Quantitative Account

IMPORTANCE

Understanding burnout among practitioners in skilled nursing facilities (SNFs) and assisted living facilities (ALFs) while considering contextual factors may lead to practices that enhance therapist and patient satisfaction as well as quality of care.

OBJECTIVE

To examine productivity standards and burnout in the context of setting and role, as reported by therapy practitioners in geriatric settings, and to explore relationships between productivity standards and perceived ethical pressures.

DESIGN

Cross-sectional online survey with descriptive data.

PARTICIPANTS

Practitioners (N = 366) included occupational therapists, physical therapists, speech-language pathologists, and occupational and physical therapy assistants working in SNFs and ALFs in the United States. A survey integrating the Maslach Burnout Inventory: Human Services Survey for Medical Personnel (MBI-HSS) and questions addressing demographics and contextual factors was distributed via social media.

RESULTS

Of 366 practitioners, 20.5% were burned out, exhibiting extreme scores for Emotional Exhaustion (EE), Depersonalization (DP), and Personal Accomplishment (PA) on the MBI-HSS. Significant relationships between productivity requirements and EE, DP, and PA, after accounting for covariates, were evident. Significant relationships between productivity standards and five of the six ethically questionable behaviors existed. Role affected productivity requirements, specifically between therapists and assistants, whereas setting did not.

CONCLUSIONS AND RELEVANCE

Productivity standards and related pressures are associated with concerning aspects of burnout among practitioners working in geriatric settings. Advocating for change in defining productivity and incorporating positive support in the work environment may assist in reducing burnout and turnover rates and improve patient satisfaction and care. Plain-Language Summary: This research highlights the prevalence of burnout and perceived pressures related to productivity requirements among occupational therapy practitioners working in skilled nursing and assisted living facilities.

Freezing Biological Time: A Modern Perspective on Organ Preservation

Transporting tissues and organs from the site of donation to the patient in need, while maintaining viability, is a limiting factor in transplantation medicine. One way in which the supply chain of organs for transplantation can be improved is to discover novel approaches and technologies that preserve the health of organs outside of the body. The dominant technologies that are currently in use in the supply chain for biological materials maintain tissue temperatures ranging from a controlled room temperature (+25 °C to +15 °C) to cryogenic (-120 °C to -196 °C) temperatures (reviewed in Criswell et al. Stem Cells Transl Med. 2022). However, there are many cells and tissues, as well as all major organs, that respond less robustly to preservation attempts, particularly when there is a need for transport over long distances that require more time. In this perspective article, we will highlight the current challenges and advances in biopreservation aimed at "freezing biological time," and discuss the future directions and requirements needed in the field.

OUP accepted manuscript

Advances in regenerative medicine manufacturing continue to be a priority for achieving the full commercial potential of important breakthrough therapies. Equally important will be the establishment of distribution chains that support the transport of live cells and engineered tissues and organs resulting from these advanced biomanufacturing processes. The importance of a well-managed distribution chain for products requiring specialized handling procedures was highlighted during the COVID-19 pandemic and serves as a reminder of the critical role of logistics and distribution in the success of breakthrough therapies. This perspective article will provide insight into current practices and future considerations for creating global distribution chains that facilitate the successful deployment of regenerative medicine therapies to the vast number of patients that would benefit from them worldwide.

What is your research question? A mixed methods evaluation of an academic statistical consulting center

Academic consulting centers on research and statistics are the bridge between applied researchers and statisticians and thus at the core of university-wide research. The client-centered evaluation focused on investigating the perspective of the clients in university research and statistical consulting center. A mixed-methods methodology was used in this study, specifically a concurrent triangulation design was implemented to have multiple data sources collected and analyzed simultaneously in order to identify areas of overlapping information. The Research Consulting Scale (RCS) instrument was developed and analyzed using an exploratory factor analysis with 129 participants and resulted in two factors: consulting experience, and consulting facilities. The internal consistency reliability of the scores for these two factors was 0.89 and .86 respectively. These results support the RCS has strong internal consistency. Additionally, client interviews were conducted sampling from those who had responded to the survey in order to gather additional data. Thematic analysis was performed to interview data and resulted in two major themes: consultant expertise and consultancy skills. The results provide a survey instrument and key themes for university consulting centers to focus and assess their efficiency through client's perspectives.

Impact of Video Modeling and Scenario-Based Learning on Work Readiness for Transition-Age Students With Disabilities

Date Presented 04/7/21

The purpose of this research is to evaluate the effectiveness of video modeling and scenario-based learning to develop interpersonal skills necessary for competitive gainful employment and postsecondary educational experiences among transition-age students with disabilities in a public school setting. Goal Attainment Scaling and the Becker Work Adjustment Profile–2 were used as outcome measures. OT's role and significance in the area of transition will be highlighted.

Primary Author and Speaker: Katherine Landsiedel

A Stitch in Time Saves Clots: Venous Thromboembolism Chemoprophylaxis in Traumatic Brain Injury

BACKGROUND

Venous thromboembolism chemoprophylaxis (VTE-CHEMO) is often delayed in patients with traumatic brain injury because of the concern for intracranial hemorrhage (ICH) progression. We hypothesize that (1) late time to VTE-CHEMO (≥48 h) is associated with higher incidence of VTE, and (2) VTE-CHEMO use does not correlate with ICH progression.

MATERIALS AND METHODS

This is a multiinstitutional retrospective study of patients with traumatic brain injury admitted between 2014 and 2016. Inclusion criteria were head Abbreviated Injury Code ≥2, ICH present on initial head computed tomography, and two or more head computed tomography scans after admission. The primary outcome was VTE, and the secondary outcome was ICH progression. Patients were classified as receiving VTE-CHEMO early (<48 h) or late (≥48 h). Multivariable analysis with Cox proportional hazards regression was performed.

RESULTS

Overall, 1803 patients were included. Patients with VTE (n = 137) were more likely to have spinal cord injury, blunt cerebrovascular injury, pelvic or femur fractures, and missed VTE-CHEMO doses. After multivariable regression, body mass index >30 (hazard ratio [HR], 1.05; P = 0.002), Injury Severity Score (HR, 1.004; P < 0.001), pelvic or femur fractures (HR, 1.05; P < 0.0001), spinal cord injury (HR, 1.28; P = 0.02), and missed VTE-CHEMO doses (HR, 1.08; P = 0.01) were significant predictors of VTE. In those who required neurosurgery, late VTE-CHEMO predicted VTE (HR, 1.21; P = 0.0001). Overall, 32% patients experienced ICH progression, which did not correlate with VTE-CHEMO use or timing.

CONCLUSIONS

This multicenter study highlights benefits from early VTE-CHEMO and identifies high-risk groups who may benefit from more aggressive prophylaxis. These data also emphasize risk to patients by withholding VTE-CHEMO.

Time to antibiotic administration: Sepsis alerts called in emergency department versus in the field via emergency medical services

INTRODUCTION

The Severe Sepsis and Septic Shock Early Management Bundle (SEP-1) identifies patients with "severe sepsis" and mandates antibiotics within a specific time window. Rapid time to administration of antibiotics may improve patient outcomes. The goal of this investigation was to compare time to antibiotic administration when sepsis alerts are called in the emergency department (ED) with those called in the field by emergency medical services (EMS).

METHODS

This was a multi-center, retrospective review of patients designated as sepsis alerts in ED or via EMS in the field, presenting to four community emergency departments over a six-month period.

RESULTS

507 patients were included, 419 in the ED alert group and 88 in the field alert group. Mean time to antibiotic administration was significantly faster in the field alert group when compared to the ED alert group (48.5 min vs 64.5 min, p < 0.001). Patients were more likely to receive antibiotics within 60 min of ED arrival in the field alert group (59.1% vs 44%, p = 0.01). Secondary outcomes including mortality, hospital length of stay, intensive care unit length of stay, sepsis diagnosis on admission, Clostridioides difficile infection rates, fluid bolus utilization, anti-MRSA antibiotic utilization rates, and anti-Pseudomonal antibiotic utilization rates were not found to be significantly different.

CONCLUSIONS

Sepsis alerts called in the field via EMS may decrease time to antibiotics and increase the likelihood of antibiotic administration occurring within 60 min of arrival when compared to those called in the ED.

Hemodynamic Effects of Propofol for Induction of Rapid Sequence Intubation in Traumatically Injured Patients

Present guidelines for emergency intubation in traumatically injured patients recommend rapid sequence intubation (RSI) as the preferred method of airway management but specific pharmacologic agents for RSI remain controversial. To evaluate hemodynamic differences between propofol and other induction agents when used for RSI in trauma patients. Single-center, retrospective review of trauma patients intubated in the emergency department. Patients were divided in two groups based on induction agent, propofol or nonpropofol. The primary outcome was incidence of hypotension within 30 minutes of intubation. Secondary outcomes included hospital length of stay and inhospital mortality. The study protocol was approved by the Institutional Review Board. Of the 744 patients identified, 83 were analyzed, 43 in the propofol group and 40 in the nonpropofol group. Groups were similar at baseline in terms of pre-RSI hemodynamics, injury mechanism, initial Glasgow Coma Score, and Injury Severity Score. On univariate analysis, although not statistically significant, postintubation hypotension was more common in patients who received propofol compared with those who did not, 39.5 per cent versus 22.5 per cent (P = 0.9). When adjusted for age, Injury Severity Score, and pre-RSI hemodynamics, the risk of hypotension among propofol-treated patients was significantly higher (OR = 3.64; 95% Confidence interval 1.16-13.24). There were no significant differences between groups in hospital length of stay or mortality. Propofol increases the odds of postintubation hypotension in traumatically injured patients. Considerable caution should be used when contemplating the use of propofol the for induction of injured patients requiring RSI because other agents possess more favorable hemodynamic profiles.

Hemodynamic Effects of Propofol for Induction of Rapid Sequence Intubation in Traumatically Injured Patients

Present guidelines for emergency intubation in traumatically injured patients recommend rapid sequence intubation (RSI) as the preferred method of airway management but specific pharmacologic agents for RSI remain controversial. To evaluate hemodynamic differences between propofol and other induction agents when used for RSI in trauma patients. Single-center, retrospective review of trauma patients intubated in the emergency department. Patients were divided in two groups based on induction agent, propofol or nonpropofol. The primary outcome was incidence of hypotension within 30 minutes of intubation. Secondary outcomes included hospital length of stay and inhospital mortality. The study protocol was approved by the Institutional Review Board. Of the 744 patients identified, 83 were analyzed, 43 in the propofol group and 40 in the nonpropofol group. Groups were similar at baseline in terms of pre-RSI hemodynamics, injury mechanism, initial Glasgow Coma Score, and Injury Severity Score. On univariate analysis, although not statistically significant, postintubation hypotension was more common in patients who received propofol compared with those who did not, 39.5 per cent versus 22.5 per cent (P = 0.9). When adjusted for age, Injury Severity Score, and pre-RSI hemodynamics, the risk of hypotension among propofol-treated patients was significantly higher (OR = 3.64; 95% Confidence interval 1.16–13.24). There were no significant differences between groups in hospital length of stay or mortality. Propofol increases the odds of postintubation hypotension in traumatically injured patients. Considerable caution should be used when contemplating the use of propofol the for induction of injured patients requiring RSI because other agents possess more favorable hemodynamic profiles.

Mechanochemical Effects on Extracellular Signal-Regulated Kinase Dynamics in Stem Cell Differentiation

Understanding how key signaling molecules are coregulated by biochemical agents and physical stimuli during stem cell differentiation is critical but often lacking. Due to the important role of extracellular signal-regulated kinase (ERK), this study has examined its temporal dynamics to determine the coregulation of mechanochemical cues on ERK phosphorylation for smooth muscle cell (SMC) differentiation. To assess ERK1/2 activity, a fluorescence resonance energy transfer-based biosensor was transfected into mesenchymal stem cells. The influences of nanopatterned substrates, growth factors, and drugs on ERK activities were related to their effects on SMC differentiation. Results revealed that nanopatterned substrates significantly increased ERK activity in cells, overriding ERK response from administered biochemical factors. The nanopatterned substrates reduced expression of SMC markers after a 48-h biochemical treatment, except for the combination with ERK inhibitor PD98059 treatment, which enhanced expression of mature SMC marker MYH11. Immunofluorescent staining for focal adhesion proteins, vinculin and zyxin, indicated no significant differences in vinculin cluster distribution or dimension, while the location of zyxin changed from adhesion sites of cell periphery on nonpatterned substrate to actin filaments on nanopatterned substrate. The zyxin-reinforced stress fibers likely enhanced the cytoskeletal tension to increase ERK dynamics. Collectively, results suggest that physical stimuli play a dominating role in initial ERK signaling and early-stage differentiation through focal adhesion changes, and the capability of monitoring signaling events in real time could be exploited to guide the engineering of cell microenvironment.

Biomimetic soft fibrous hydrogels for contractile and pharmacologically responsive smooth muscle

The ability to assess changes in smooth muscle contractility and pharmacological responsiveness in normal or pathological-relevant vascular tissue environments is critical to enable vascular drug discovery. However, major challenges remain in both capturing the complexity of in vivo vascular remodeling and evaluating cell contractility in complex, tissue-like environments. Herein, we developed a biomimetic fibrous hydrogel with tunable structure, stiffness, and composition to resemble the native vascular tissue environment. This hydrogel platform was further combined with the combinatory protein array technology as well as advanced approaches to measure cell mechanics and contractility, thus permitting evaluation of smooth muscle functions in a variety of tissue-like microenvironments. Our results demonstrated that biomimetic fibrous structure played a dominant role in smooth muscle function, while the presentation of adhesion proteins co-regulated it to various degrees. Specifically, fibre networks enabled cell infiltration and upregulated expression of actomyosin proteins in contrast to flat hydrogels. Remarkably, fibrous structure and physiologically relevant stiffness of hydrogels cooperatively enhanced smooth muscle contractility and pharmacological responses to vasoactive drugs at both the single cell and intact tissue levels. Together, this study is the first to demonstrate alterations of human vascular smooth muscle contractility and pharmacological responsiveness in biomimetic soft, fibrous environments with a cellular array platform. The integrated platform produced here could enable investigations for pathobiology and pharmacological interventions by developing a broad range of patho-physiologically relevant in vitro tissue models.

STATEMENT OF SIGNIFICANCE

Engineering functional smooth muscle in vitro holds the great potential for diseased tissue replacement and drug testing. A central challenge is recapitulating the smooth muscle contractility and pharmacological responses given its significant phenotypic plasticity in response to changes in environment. We present a biomimetic fibrous hydrogel with tunable structure, stiffness, and composition that enables the creation of functional smooth muscle tissues in the native-like vascular tissue microenvironment. Such fibrous hydrogel is further combined with the combinatory protein array technology to construct a cellular array for evaluation of smooth muscle phenotype, contraction, and cell mechanics. The integrated platform produced here could be promising for developing a broad range of normal or diseased in vitro tissue models.

A photoclickable peptide microarray platform for facile and rapid screening of 3-D tissue microenvironments

Microarrays are powerful experimental tools for high-throughput screening of cellular behavior in multivariate microenvironments. Here, we present a new, facile and rapid screening method for probing cellular behavior in 3D tissue microenvironments. This method utilizes a photoclickable peptide microarray platform developed using electrospun fibrous poly(ethylene glycol) hydrogels and microarray contact printing. We investigated the utility of this platform with five different peptide motifs and ten cell types including stem, terminally differentiated, cancer or immune cells that were from either primary origin or cell lines and from different species. We validated the capabilities of this platform to screen arrays consisting of multiple peptide motifs and concentrations for selectivity to cellular adhesion and morphology. Moreover, this platform is amenable to controlled spatial presentation of peptides. We show that by leveraging the differential attachment affinities for two cell types to two different peptides, this platform can also be used to investigate cell-cell interactions through miniature co-culture peptide arrays. Our fibrous peptide microarray platform enables high-throughput screening of 3D tissue microenvironments in a facile and rapid manner to investigate cell-matrix interactions and cell-cell signaling and to identify optimal tissue microenvironments for cell-based therapies.

High-Throughput Screening of Vascular Endothelium-Destructive or Protective Microenvironments: Cooperative Actions of Extracellular Matrix Composition, Stiffness, and Structure

Pathological modification of the subendothelial extracellular matrix (ECM) has closely been associated with endothelial activation and subsequent cardiovascular disease progression. To understand regulatory mechanisms of these matrix modifications, the majority of previous efforts have focused on the modulation of either chemical composition or matrix stiffness on 2D smooth surfaces without simultaneously probing their cooperative effects on endothelium function on in vivo like 3D fibrous matrices. To this end, a high-throughput, combinatorial microarray platform on 2D and 3D hydrogel settings to resemble the compositions, stiffness, and structure of healthy and diseased subendothelial ECM has been established, and further their respective and combined effects on endothelial attachment, proliferation, inflammation, and junctional integrity have been investigated. For the first time, the results demonstrate that 3D fibrous structure resembling native ECM is a critical endothelium-protective microenvironmental factor by maintaining the stable, quiescent endothelium with strong resistance to proinflammatory stimuli. It is also revealed that matrix stiffening, in concert with chemical compositions resembling diseased ECM, particularly collagen III, could aggravate activation of nuclear factor kappa B, disruption of endothelium integrity, and susceptibility to proinflammatory stimuli. This study elucidates cooperative effects of various microenvironmental factors on endothelial activation and sheds light on new in vitro model for cardiovascular diseases.

[Conception and Preliminary Evaluation of a Rehabilitation-Attending Counseling Service for Caregivers of Stroke Patients]

This paper presents the pilot project "The Caregivers' Guide", which is financed by the German Federal Ministry of Education and Research (BMBF). The project's concept is outreach-oriented and personal, giving constant support to relatives of stroke patients throughout rehabilitation. Its effects were reviewed in an accompanying study. A combination of qualitative and quantitative methods was chosen to gather data on the experiences and assessments of the caregivers, as well as changes during the counselling process. 62 caregivers completed questionnaires before and after the intervention. Additionally, 30 qualitative interviews were carried out. Positive effects could be observed in accordance with the project goals, especially regarding provision of appropriate information, burden reduction and strengthening clients' resources. The accompaniment by a fixed reference person was viewed as helpful, the combination of professional knowledge and emotional support was deemed most essential. The concept "The Caregivers' Guide" is suitable as an impetus of innovation regarding the development of counseling structures for family caregivers.

Mussel-inspired polydopamine for bio-surface functionalization

Surface functionalization via molecular design has been a key approach to incorporate new functionalities into existing biomaterials for biomedical application. Mussel-inspired polydopamine (PDA) has aroused great interest as a new route to the functionalization of biomaterials, due to its simplicity and material independency in deposition, favorable interactions with cells, and strong reactivity for secondary functionalization. Herein, this review attempts to highlight the recent findings and progress of PDA in bio-surface functionalization for biomedical applications. The efforts made to elucidate the polymerization mechanism, PDA structure, and the preparation parameters have been discussed. Interactions between PDA coatings and the various cell types involved in different biomedical applications including general cell adhesion, bone regeneration, blood compatibility, and antimicrobial activity have also been highlighted. A brief discussion of post-functionalization of PDA and nanostructured PDA is also provided.

Processing Techniques and Applications of Silk Hydrogels in Bioengineering

Hydrogels are an attractive class of tunable material platforms that, combined with their structural and functional likeness to biological environments, have a diversity of applications in bioengineering. Several polymers, natural and synthetic, can be used, the material selection being based on the required functional characteristics of the prepared hydrogels. Silk fibroin (SF) is an attractive natural polymer for its excellent processability, biocompatibility, controlled degradation, mechanical properties and tunable formats and a good candidate for the fabrication of hydrogels. Tremendous effort has been made to control the structural and functional characteristic of silk hydrogels, integrating novel biological features with advanced processing techniques, to develop the next generation of functional SF hydrogels. Here, we review the several processing methods developed to prepare advanced SF hydrogel formats, emphasizing a bottom-up approach beginning with critical structural characteristics of silk proteins and their behavior under specific gelation environments. Additionally, the preparation of SF hydrogel blends and other advanced formats will also be discussed. We conclude with a brief description of the attractive utility of SF hydrogels in relevant bioengineering applications.

Formative evaluation: Developing measures for online family mental health recovery education

Families facing mental health challenges have very limited access to ongoing support. A formative evaluation of Families Healing Together (FHT), a new online family mental health recovery program was conducted using five waves (N=108) of data. Exploratory factor analysis of the measures identified as important to the program theory found strong reliability evidence (α=.77-.86) for 6 constructs. A poor response rate (25%) did not allow for valid pre and postoutcome evaluation, however we did have enough information to assess the psychometric properties of the new measures. The new evaluation tool accounted for 34% of the variance in Capacity to Support Family Member, and nearly 50% of the variance in Hopefulness toward Recovery. New programs without existing measures require formative evaluation strategies that accurately describe program activities in order to develop outcome measures sensitive to novel aspects of program components. Most outcome measures are developed for individuals with mental health challenges not family members. These new measures may be beneficial to effectively evaluate programs that promote family recovery and wellness.

Human mesenchymal stem cells cultured on silk hydrogels with variable stiffness and growth factor differentiate into mature smooth muscle cell phenotype

Cell-matrix and cell-biomolecule interactions play critical roles in a diversity of biological events including cell adhesion, growth, differentiation, and apoptosis. Evidence suggests that a concise crosstalk of these environmental factors may be required to direct stem cell differentiation toward matured cell type and function. However, the culmination of these complex interactions to direct stem cells into highly specific phenotypes in vitro is still widely unknown, particularly in the context of implantable biomaterials. In this study, we utilized tunable hydrogels based on a simple high pressure CO2 method and silk fibroin (SF) the structural protein of Bombyx mori silk fibers. Modification of SF protein starting water solution concentration results in hydrogels of variable stiffness while retaining key structural parameters such as matrix pore size and β-sheet crystallinity. To further resolve the complex crosstalk of chemical signals with matrix properties, we chose to investigate the role of 3D hydrogel stiffness and transforming growth factor (TGF-β1), with the aim of correlating the effects on the vascular commitment of human mesenchymal stem cells. Our data revealed the potential to upregulate matured vascular smooth muscle cell phenotype (myosin heavy chain expression) of hMSCs by employing appropriate matrix stiffness and growth factor (within 72h). Overall, our observations suggest that chemical and physical stimuli within the cellular microenvironment are tightly coupled systems involved in the fate decisions of hMSCs. The production of tunable scaffold materials that are biocompatible and further specialized to mimic tissue-specific niche environments will be of considerable value to future tissue engineering platforms.

STATEMENT OF SIGNIFICANCE

This article investigates the role of silk fibroin hydrogel stiffness and transforming growth factor (TGF-β1), with the aim of correlating the effects on the vascular commitment of human mesenchymal stem cells. Specifically, we demonstrate the upregulation of mature vascular smooth muscle cell phenotype (myosin heavy chain expression) of hMSCs by employing appropriate matrix stiffness and growth factor (within 72h). Moreover, we demonstrate the potential to direct specialized hMSC differentiation by modulating stiffness and growth factor using silk fibroin, a well-tolerated and -defined biomaterial with an impressive portfolio of tissue engineering applications. Altogether, our study reinforce the fact that complex differentiation protocols may be simplified by engineering the cellular microenvironment on multiple scales, i.e. matrix stiffness with growth factor.

Three-dimensional, soft neotissue arrays as high throughput platforms for the interrogation of engineered tissue environments

Local signals from tissue-specific extracellular matrix (ECM) microenvironments, including matrix adhesive ligand, mechanical elasticity and micro-scale geometry, are known to instruct a variety of stem cell differentiation processes. Likewise, these signals converge to provide multifaceted, mechanochemical cues for highly-specific tissue morphogenesis or regeneration. Despite accumulated knowledge about the individual and combined roles of various mechanochemical ECM signals in stem cell activities on 2-dimensional matrices, the understandings of morphogenetic or regenerative 3-dimenstional tissue microenvironments remain very limited. To that end, we established high-throughput platforms based on soft, fibrous matrices with various combinatorial ECM proteins meanwhile highly-tunable in elasticity and 3-dimensional geometry. To demonstrate the utility of our platform, we evaluated 64 unique combinations of 6 ECM proteins (collagen I, collagen III, collagen IV, laminin, fibronectin, and elastin) on the adhesion, spreading and fate commitment of mesenchymal stem cell (MSCs) under two substrate stiffness (4.6 kPa, 20 kPa). Using this technique, we identified several neotissue microenvironments supporting MSC adhesion, spreading and differentiation toward early vascular lineages. Manipulation of the matrix properties, such as elasticity and geometry, in concert with ECM proteins will permit the investigation of multiple and distinct MSC environments. This paper demonstrates the practical application of high through-put technology to facilitate the screening of a variety of engineered microenvironments with the aim to instruct stem cell differentiation.

Synergism of matrix stiffness and vascular endothelial growth factor on mesenchymal stem cells for vascular endothelial regeneration

Mesenchymal stem cells (MSCs) hold tremendous potential for vascular tissue regeneration. Research has demonstrated that individual factors in the cell microenvironment such as matrix elasticity and growth factors regulate MSC differentiation to vascular lineage. However, it is not well understood how matrix elasticity and growth factors combine to direct the MSC fate. This study examines the combined effects of matrix elasticity and vascular endothelial growth factor (VEGF) on both MSC differentiation into endothelial lineage and MSC paracrine signaling. MSCs were seeded in soft nanofibrous matrices with or without VEGF, and in Petri dishes with or without VEGF. Only MSCs seeded in three-dimensional soft matrices with VEGF showed significant increases in the expression of endothelial markers (vWF, eNOS, Flt-1, and Flk-1), while eliminating the expression of smooth muscle marker (SM-α-actin). MSCs cultured in VEGF alone on two-dimensional dishes showed increased expression of both early-stage endothelial and smooth muscle markers, indicating immature vascular differentiation. Furthermore, MSCs cultured in soft matrices with VEGF showed faster upregulation of endothelial markers compared with MSCs cultured in VEGF alone. Paracrine signaling studies found that endothelial cells cultured in the conditioned media from MSCs differentiated in the soft matrix and VEGF condition exhibited increased migration and formation of capillary-like structures. These results demonstrate that VEGF and soft matrix elasticity act synergistically to guide MSC differentiation into mature endothelial phenotype while enhancing paracrine signaling. Therefore, it is critical to control both mechanical and biochemical factors to safely regenerate vascular tissues with MSCs.

[First results with catheter and magnetically guided and detached polymerized ferromagnetic particle filaments and heat-induced particle release using the Stereotaxis Niobe system]

PURPOSE

To develop a new technique for intravascular guidance and the release of magnetized ferromagnetic nanoparticles using a polymerized filament by means of an external magnetic field.

MATERIALS AND METHODS

Ferromagnetic nanoscaled beads were embedded in temperature-sensitive gels to form filaments after polymerization. Deflection of the filaments was assessed in a Stereotaxis Niobe magnetic navigation system (MNS) in comparison with dedicated guide wires. The curvature was measured as a surrogate parameter for deflection. In combination with commercially available catheters, the filaments were navigated in a perfused aneurysmatic vessel model and a perfused branched vessel model under the influence of two permanent magnets of the Niobe MNS. The magnetic field vector was varied in all three dimensions. After positioning, the magnetic colloid-containing filaments were exposed to an electromagnetic field of 45 kA/m, 200 kHz for a period of 5 minutes for non-invasive heating.

RESULTS

The filaments showed superior deflectability compared to the dedicated guide wires (p = 0.0091). The curvature was 0.54 +/- 0.12 mm(-1) for the filaments and 0.33 +/- 0.21 mm(-1) for the guide wires. In combination with angiography catheters, magnetic guidance and accumulation of specially designed filaments were possible in the perfused vessel model. Inductive heating allowed non-invasive disintegration and releasing of the nanoparticles in all filaments.

CONCLUSION

This feasibility study shows that magnetic guidance and targeting of a specially designed magnetic colloid-containing filament and subsequent disintegration are feasible. This technique offers the potential for controlled local drug release.

[Quality of life improvement (SF-36) after implantation of a knee endoprosthesis]

From a group of 41 consecutive patients receiving an endoprosthetic knee replacement 35 patients underwent complete pre- and postoperative documentation of life quality in the short term follow-up. The comparison of pre- and postoperative life quality assessment with the SF-36 form showed significant differences on the 5% level for the categories "somatic pain" and "psychological wellness". The parameter "somatic functionality" showed with a P-value of 0.0616 almost significant improvement. The other parameters also showed improved values without reaching statistical significance. In summary, after implantation of a total knee replacement an improvement of life quality can be documented.