Well-Being Therapy in systemic sclerosis outpatients: a randomized controlled trial.

OBJECTIVES: Systemic Sclerosis (SSc) patients have psychological distress and poor well-being and need a tailored treatment. Psychological interventions, rarely tested for efficacy, showed poor benefits. The present randomized controlled trial tested the efficacy of Well-Being Therapy (WBT) in SSc patients. METHODS: Thirty-two outpatients were randomized (1:1) to WBT (n = 16) or Treatment As Usual (i.e. routine medical check-ups) (TAU) (n = 16). Primary outcome was well-being. Secondary outcomes included functional ability related to SSc, psychological distress, mental pain, suffering. All participants were assessed at baseline (T0). The WBT group was assessed after two months (end of WBT session 4) (T1), after four months (end of WBT session 8) (T2), after seven months (3-month follow-up) (T3), and after 10 months (6-month follow-up) (T4). The TAU group was assessed two (T1), four (T2), seven (T3), and ten (T4) months after baseline. RESULTS: WBT produced a significant improvement in subjective well-being (p ≤ 0.001), personal growth (p = 0.006), self-acceptance (p = 0.003) compared with TAU, maintained at T3 as what concerns subjective well-being (p = 0.012). WBT produced greater decrease in psychological distress (p = 0.010), mental pain (p = 0.010), suffering (p ≤ 0.001) compared with TAU, maintained at T4 as what concerns suffering (p ≤ 0.001). Participants reported high satisfaction with WBT. CONCLUSION: The study provides preliminary evidence on the benefits of WBT as short-term approach for in- and out-patient SSc healthcare paths. Studies with larger samples are needed to have the evidence for recommending WBT to SSc patients.

Ex Vivo Preservation of Ovine Periosteum Using a Perfusion Bioreactor System.

Periosteum is a highly vascularized membrane lining the surface of bones. It plays essential roles in bone repair following injury and reconstruction following invasive surgeries. To broaden the use of periosteum, including for augmenting in vitro bone engineering and/or in vivo bone repair, we have developed an ex vivo perfusion bioreactor system to maintain the cellular viability and metabolism of surgically resected periosteal flaps. Each specimen was placed in a 3D printed bioreactor connected to a peristaltic pump designed for the optimal flow rates of tissue perfusate. Nutrients and oxygen were perfused via the periosteal arteries to mimic physiological conditions. Biochemical assays and histological staining indicate component cell viability after perfusion for almost 4 weeks. Our work provides the proof-of-concept of ex vivo periosteum perfusion for long-term tissue preservation, paving the way for innovative bone engineering approaches that use autotransplanted periosteum to enhance in vivo bone repair.

Clinimetric properties of the diagnostic criteria for psychosomatic research among the elderly.

INTRODUCTION: Among the elderly, the availability of tool assessing psychosomatic syndromes is limited. The present study aims at testing inter-rater reliability and concurrent validity of the semi-structured interview for the Diagnostic Criteria for Psychosomatic Research (DCPR-R-SSI) in the elderly of the general population. METHOD: One hundred eight subjects were recruited. Participants received a clinical assessment which included the DCPR-R-SSI, the Illness Attitude Scale (IAS), the Geriatric Depression Scale (GDS), the Psychosocial Index (PSI), the Toronto Alexithymia Scale-20 (TAS-20). Analyses of inter-rater reliability of DCPR-R-SSI and concurrent validity between DCPR-R-SSI and self-administered questionnaires were conducted. RESULTS: DCPR-R-SSI showed excellent inter-rater reliability with a percent of agreement of 90.7% (K Cohen: 0.856 [SE = 0.043], 95% CI: 0.77-0.94). DCPR-R demoralization showed fair concurrent validity with GDS; concurrent validity was also fair between DCPR-R Alexithymia and TAS-20, and between DCPR-R allostatic overload and PSI allostatic load, while the concurrent validity between DCPR-R Disease Phobia and IAS was moderate. CONCLUSION: DCPR-R-SSI represents a reliable and valid tool to assess psychosomatic syndromes in the elderly. DCPR-R is in need of being implemented in the elderly clinical evaluation.

Defined Microenvironments Trigger In Vitro Gastrulation in Human Pluripotent Stem Cells.

Gastrulation is a stage in embryo development where three germ layers arise to dictate the human body plan. In vitro models of gastrulation have been demonstrated by treating pluripotent stem cells with soluble morphogens to trigger differentiation. However, in vivo gastrulation is a multistage process coordinated through feedback between soluble gradients and biophysical forces, with the multipotent epiblast transforming to the primitive streak followed by germ layer segregation. Here, the authors show how constraining pluripotent stem cells to hydrogel islands triggers morphogenesis that mirrors the stages preceding in vivo gastrulation, without the need for exogenous supplements. Within hours of initial seeding, cells display a contractile phenotype at the boundary, which leads to enhanced proliferation, yes-associated protein (YAP) translocation, epithelial to mesenchymal transition, and emergence of SRY-box transcription factor 17 (SOX17)+ T/BRACHYURY+ cells. Molecular profiling and pathway analysis reveals a role for mechanotransduction-coupled wingless-type (WNT) signaling in orchestrating differentiation, which bears similarities to processes observed in whole organism models of development. After two days, the colonies form multilayered aggregates, which can be removed for further growth and differentiation. This approach demonstrates how materials alone can initiate gastrulation, thereby providing in vitro models of development and a tool to support organoid bioengineering efforts.

Ceramic Omnidirectional Bioprinting in Cell-laden Suspensions for the Generation of Bone Analogs.

Structurally, bone tissue is an inorganic-organic composite containing metabolically active cells embedded within a hierarchical, highly mineralized matrix. This organization is challenging to replicate due to the heterogeneous environment of bone. Ceramic omnidirectional bioprinting in cell-suspensions (COBICS) is a microgel-based bioprinting technique that uniquely replicates the mineral and cellular structure of bone. COBICS prints complex, biologically relevant constructs without the need for sacrificial support materials or harsh postprocessing steps (e.g., radiation and high-temperature sintering), which are two of the biggest challenges in the additive manufacturing of bone mimetic constructs. This technique is enabled via the freeform extrusion of a novel calcium phosphate-based ink within a gelatin-based microgel suspension. The yield-stress properties of the suspension allow deposition and support the printed bone structure. UV crosslinking and nanoprecipitation then "lock" it in place. The ability to print nanostructured bone-mimetic ceramics within cell-laden biomaterials provides spatiotemporal control over macro- and micro-architecture and facilitates the real-time fabrication of complex bone constructs in clinical settings.

Biomaterials directed activation of a cryostable therapeutic secretome in induced pluripotent stem cell derived mesenchymal stromal cells.

Mesenchymal stem cell therapy has suffered from wide variability in clinical efficacy, largely due to heterogeneous starting cell populations and large-scale cell death during and after implantation. Optimizing the manufacturing process has led to reproducible cell populations that can be cryopreserved for clinical applications. Nevertheless, ensuring a reproducible cell state that persists after cryopreservation remains a significant challenge, and is necessary to ensure reproducible clinical outcomes. Here we demonstrate how matrix-conjugated hydrogel cell culture materials can normalize a population of induced pluripotent stem cell derived mesenchymal stem cells (iPSC-MSCs) to display a defined secretory profile that promotes enhanced neovascularization in vitro and in vivo. Using a protein-conjugated biomaterials screen we identified two conditions-1 kPa collagen and 10 kPa fibronectin coated polyacrylamide gels-that promote reproducible secretion of pro-angiogenic and immunomodulatory cytokines from iPSC-MSCs that enhance tubulogenesis of endothelial cells in Geltrex and neovascularization in chick chorioallantoic membranes. Using defined culture substrates alone, we demonstrate maintenance of secretory activity after cryopreservation for the first time. This advance provides a simple and scalable approach for cell engineering and subsequent manufacturing, toward normalizing and priming a desired cell activity for clinical regenerative medicine.

Clinical utility of the Diagnostic Criteria for Psychosomatic Research for a comprehensive assessment of the elderly.

INTRODUCTION: According to the revised version of the Diagnostic Criteria for Psychosomatic Research (DCPR-R), this study explored the prevalence and clinical correlates of DCPR-R psychosomatic syndromes in the elderly and tested whether DCPR-R provide an incremental contribution to the prediction of psychosocial functioning over and above DSM-5. METHOD: One hundred seven elderly subjects were recruited. Participants received a clinical assessment, which included the DCPR-Revised Semi-Structured Interview (DCPR-R SSI), the Structured Clinical Interview for DSM-5-Clinician Version (SCID-5-CV), the Psychological Well-Being (PWB) Scales, the Geriatric Anxiety Scale (GAS) and the Geriatric Depression Scale (GDS). Analyses of covariance (ANCOVA) and hierarchical regression analyses were run. RESULTS: Twenty-two (20.6%) subjects had at least one DSM-5 diagnosis, and 62 (57.9%) reported at least one DCPR-R diagnosis. Subjects with at least one DCPR-R diagnosis showed lower PWB Personal Growth and PWB Purpose in Life than those without DCPR-R diagnoses. When the incremental validity of the DCPR-R was tested using PWB Personal Growth, PWB Purpose in Life, PWB Self-acceptance, GAS Cognitive symptoms and GAS affective symptoms subscales as criterion variable, the DCPR-R increased up to 0.135-0.263 the explained variance. CONCLUSION: The DCPR-R might be implemented together with the DSM-5 to have a comprehensive assessment of elderly subjects.

Anxiety in the Medically Ill: A Systematic Review of the Literature.

Background: Although anxiety is highly represented in the medically ill and its occurrence has relevant clinical implications, it often remains undetected and not properly treated. This systematic review aimed to report on anxiety, either symptom or disorder, in patients who suffer from a medical illness. Methods: English-language papers reporting on anxiety in medically ill adults were evaluated. PubMed, PsycINFO, Web of Science, and Cochrane databases were systematically searched from inception to June 2021. Search term was "anxiety" combined using the Boolean "AND" operator with "medically ill/chronic illness/illness/disorder/disease." Risk of bias was assessed via the Joanna Briggs Institute (JBI) Critical Appraisal Tools-Checklist for Prevalence Studies. The PRISMA guidelines were followed. Results: Of 100,848 citations reviewed, 329 studies met inclusion criteria. Moderate or severe anxious symptoms were common among patients with cardiovascular, respiratory, central nervous system, gastrointestinal, genitourinary, endocrine, musculoskeletal system or connective tissue, dermatological diseases, cancer, AIDS and COVID-19 infections. The most common anxiety disorder was generalized anxiety disorder, observed among patients with cardiovascular, respiratory, central nervous system, dermatologic diseases, cancer, primary aldosteronism, amenorrhea, and COVID-19 infection. Panic disorder was described for cardiovascular, respiratory, dermatology diseases. Social anxiety was found for cardiovascular, respiratory, rheumatoid diseases. Specific phobias were relatively common in irritable bowel syndrome, gastroesophageal reflux, end-stage renal disease. Conclusion: Anxiety is a major challenge in medical settings. Recognition and proper assessment of anxiety in patients who suffer from a medical illness is necessary for an appropriate management. Future reviews are warranted in order also to clarify the causal and temporal relationship between anxiety and organic illness.

Clinical Utility of Semistructured Interview and Scales to Assess Withdrawal Syndromes With Dose Reduction or Discontinuation of Selective Serotonin Reuptake Inhibitors or Serotonin Norepinephrine Reuptake Inhibitors.

BACKGROUND: Withdrawal syndromes can occur after dose reduction or discontinuation of selective serotonin reuptake inhibitors (SSRIs) or serotonin-norepinephrine reuptake inhibitors (SNRIs). Few measurement instruments are available to assess them: Diagnostic Clinical Interview for Drug Withdrawal 1-New Symptoms of SSRI and SNRI (DID-W1) and Discontinuation Emergent Signs and Symptoms (DESS) checklist. We assessed their interrater reliability, verified the percent agreement between the two, and tested DESS sensitivity and specificity on the basis of the diagnoses formulated via the DID-W1. METHODS: One-hundred thirty-four subjects who referred for withdrawal at 3 outpatient facilities were enrolled and assessed via the DESS and the DID-W1. Percent agreement and Cohen κ were calculated to measure DID-W1 and DESS interrater reliability, as well as the agreement between DID-W1 and DESS items. Sensitivity and specificity of DESS were derived from the identification of true-positive, false-negative, true-negative, and false-positive on the DID-W1. RESULTS: Both tools showed excellent interrater reliability (DID-W1 Cohen κ = 0.958; DESS Cohen κ = 0.81-1). The degree of agreement between DID-W1 and DESS items was poor or fair (Cohen κ < 0.40) for some items and moderate (Cohen κ = 0.41-0.60) for others. Sensitivity and specificity of DESS were 0.937 (true-positive = 60, false-negative = 4) and 0.285 (true-negative = 20, false-positive = 50), respectively. CONCLUSIONS: DID-W1 was a reliable method to identify and diagnose withdrawal syndromes. The DESS checklist showed to be a useful tool for detecting withdrawal SSRI/SNRI symptoms when the aim is to achieve high sensitivity to identify true positives.

Pluripotent stem cell-derived mesenchymal stromal cells improve cardiac function and vascularity after myocardial infarction.

BACKGROUND AIMS: Mesenchymal stromal cells (MSCs) have been shown to improve cardiac function after injury and are the subject of ongoing clinical trials. In this study, the authors tested the cardiac regenerative potential of an induced pluripotent stem cell-derived MSC (iPSC-MSC) population (Cymerus MSCs) in a rat model of myocardial ischemia-reperfusion (I/R). Furthermore, the authors compared this efficacy with bone marrow-derived MSCs (BM-MSCs), which are the predominant cell type in clinical trials. METHODS: Four days after myocardial I/R injury, rats were randomly assigned to (i) a Cymerus MSC group (n = 15), (ii) a BM-MSC group (n = 15) or (iii) a vehicle control group (n = 14). For cell-treated animals, a total of 5 × 106 cells were injected at three sites within the infarcted left ventricular (LV) wall. RESULTS: One month after cell transplantation, Cymerus MSCs improved LV function (assessed by echocardiography) compared with vehicle and BM-MSCs. Interestingly, Cymerus MSCs enhanced angiogenesis without sustained engraftment or significant impact on infarct scar size. Suggesting safety, Cymerus MSCs had no effect on inducible tachycardia or the ventricular scar heterogeneity that provides a substrate for cardiac re-entrant circuits. CONCLUSIONS: The authors here demonstrate that intra-myocardial administration of iPSC-MSCs (Cymerus MSCs) provide better therapeutic effects compared with conventional BM-MSCs in a rodent model of myocardial I/R. Because of its manufacturing scalability, iPSC-MSC therapy offers an exciting opportunity for an "off-the-shelf" stem cell therapy for cardiac repair.

Development of collagen-poly(caprolactone)-based core-shell scaffolds supplemented with proteoglycans and glycosaminoglycans for ligament repair.

Core-shell scaffolds offer a promising regenerative solution to debilitating injuries to anterior cruciate ligament (ACL) thanks to a unique biphasic structure. Nevertheless, current core-shell designs are impaired by an imbalance between permeability, biochemical and mechanical cues. This study aimed to address this issue by creating a porous core-shell construct which favors cell infiltration and matrix production, while providing mechanical stability at the site of injury. The developed core-shell scaffold combines an outer shell of electrospun poly(caprolactone) fibers with a freeze-dried core of type I collagen doped with proteoglycans (biglycan, decorin) or glycosaminoglycans (chondroitin sulphate, dermatan sulphate). The aligned fibrous shell achieved an elastic modulus akin of the human ACL, while the porous collagen core is permeable to human mesenchymal stem cell (hMSC). Doping of the core with the aforementioned biomolecules led to structural and mechanical changes in the pore network. Assessment of cellular metabolic activity and scaffold contraction shows that hMSCs actively remodel the matrix at different degrees, depending on the core's doping formulation. Additionally, immunohistochemical staining and mRNA transcript levels show that the collagen-chondroitin sulphate formulation has the highest matrix production activity, while the collagen-decorin formulation featured a matrix production profile more characteristic of the undamaged tissue. Together, this demonstrates that scaffold doping with target biomolecules leads to distinct levels of cell-mediated matrix remodeling. Overall, this work resulted in the development of a versatile and robust platform with a combination of mechanical and biochemical features that have a significant potential in promoting the repair process of ACL tissue.

Targeting cell plasticity for regeneration: From in vitro to in vivo reprogramming.

The discovery of induced pluripotent stem cells (iPSCs), reprogrammed to pluripotency from somatic cells, has transformed the landscape of regenerative medicine, disease modelling and drug discovery pipelines. Since the first generation of iPSCs in 2006, there has been enormous effort to develop new methods that increase reprogramming efficiency, and obviate the need for viral vectors. In parallel to this, the promise of in vivo reprogramming to convert cells into a desired cell type to repair damage in the body, constitutes a new paradigm in approaches for tissue regeneration. This review article explores the current state of reprogramming techniques for iPSC generation with a specific focus on alternative methods that use biophysical and biochemical stimuli to reduce or eliminate exogenous factors, thereby overcoming the epigenetic barrier towards vector-free approaches with improved clinical viability. We then focus on application of iPSC for therapeutic approaches, by giving an overview of ongoing clinical trials using iPSCs for a variety of health conditions and discuss future scope for using materials and reagents to reprogram cells in the body.

Criterion-related validity in a sample of migraine outpatients: the diagnostic criteria for psychosomatic research.

OBJECTIVE: The Diagnostic Criteria for Psychosomatic Research (DCPR) are those of psychosomatic syndromes that did not find room in the classical taxonomy. More recently, the DCPR were updated, called DCPR-revised (DCPR-R). The present study was conducted to test the criterion-related validity of the DCPR-R. METHODS: Two hundred consecutive subjects were enrolled at the Headache Center of Careggi University Hospital (Italy): 100 subjects had a diagnosis of chronic migraine (CM) and 100 had a diagnosis of episodic migraine (EM). Participants received a clinical assessment, which included the DCPR-revised Semi-Structured Interview (DCPR-R SSI), the Structured Clinical Interview for DSM-5 (SCID-5), and the psychosocial index (PSI). RESULTS: Forty-seven subjects (23.5%) had at least one DSM-5 diagnosis: major depressive disorder (8.5%; n = 17) and agoraphobia (7.5%; n = 15) were the most frequent. One hundred and ten subjects (55%) reported a DCPR-R diagnosis: allostatic overload (29%; n = 58) and type A behavior (10.5%; n = 21) were the most frequent. When the incremental validity of the DCPR system over the DSM system was tested using PSI subscales as the criterion variable, the DCPR-R increased up to 0.11-0.24 the amount of explained variance. Subjects with at least one DCPR-R diagnosis showed lower PSI well-being scores (p = .001), higher PSI stress scores (p < .001), and higher PSI psychological distress scores (p = .008) than subjects without a DCPR-R diagnosis. CONCLUSION: The DCPR-R showed a good criterion-related validity in migraine outpatients. Thus, they might be implemented, together with the DSM-5, in the assessment of migraine subjects.

iPSC Bioprinting: Where are We at?

Here, we present a concise review of current 3D bioprinting technologies applied to induced pluripotent stem cells (iPSC). iPSC have recently received a great deal of attention from the scientific and clinical communities for their unique properties, which include abundant adult cell sources, ability to indefinitely self-renew and differentiate into any tissue of the body. Bioprinting of iPSC and iPSC derived cells combined with natural or synthetic biomaterials to fabricate tissue mimicked constructs, has emerged as a technology that might revolutionize regenerative medicine and patient-specific treatment. This review covers the advantages and disadvantages of bioprinting techniques, influence of bioprinting parameters and printing condition on cell viability, and commonly used iPSC sources, and bioinks. A clear distinction is made for bioprinting techniques used for iPSC at their undifferentiated stage or when used as adult stem cells or terminally differentiated cells. This review presents state of the art data obtained from major searching engines, including Pubmed/MEDLINE, Google Scholar, and Scopus, concerning iPSC generation, undifferentiated iPSC, iPSC bioprinting, bioprinting techniques, cartilage, bone, heart, neural tissue, skin, and hepatic tissue cells derived from iPSC.

3D Printing of Bioceramic Scaffolds-Barriers to the Clinical Translation: From Promise to Reality, and Future Perspectives.

In this review, we summarize the challenges of the three-dimensional (3D) printing of porous bioceramics and their translational hurdles to clinical applications. The state-of-the-art of the major 3D printing techniques (powder-based and slurry-based), their limitations and key processing parameters are discussed in detail. The significant roadblocks that prevent implementation of 3D printed bioceramics in tissue engineering strategies, and medical applications are outlined, and the future directions where new research may overcome the limitations are proposed. In recent years, there has been an increasing demand for a nanoscale control in 3D fabrication of bioceramic scaffolds via emerging techniques such as digital light processing, two-photon polymerization, or large area maskless photopolymerization. However, these techniques are still in a developmental stage and not capable of fabrication of large-sized bioceramic scaffolds; thus, there is a lack of sufficient data to evaluate their contribution. This review will also not cover polymer matrix composites reinforced with particulate bioceramics, hydrogels reinforced with particulate bioceramics, polymers coated with bioceramics and non-porous bioceramics.

Porous Chitosan Films Support Stem Cells and Facilitate Sutureless Tissue Repair.

Photochemical tissue bonding with chitosan-based adhesive films is an experimental surgical technique that avoids the risk of thermal tissue injuries and the use of sutures to maintain strong tissue connection. This technique is advantageous over other tissue repair methods as it is minimally invasive and does not require mixing of multiple components before or during application. To expand the capability of the film to beyond just a tissue bonding device and promote tissue regeneration, in this study, we designed bioadhesive films that could also support stem cells. The films were modified with oligomeric chitosan to tune their erodibility and made porous through freeze-drying for better tissue integration. Of note, porous adhesive films (pore diameter ∼110 µm), with 10% of the chitosan being oligomeric, could retain similar tissue bonding strengths (13-15 kPa) to that of the nonporous chitosan-based adhesives used in previous studies when photoactivated. When tested in vitro, these films exhibited a mass loss of ∼20% after 7 days, swelling ratios of ∼270-300%, a percentage elongation of ∼90%, and both a tensile strength and Young's modulus of ∼1 MPa. The physical properties of the films were suitable for maintaining the viability and multipotency of bone-marrow-derived human mesenchymal stem cells over the duration of culture. Thus, these biocompatible, photoactivated porous, and erodible adhesive films show promise for applications in controlled cell delivery and regenerative medicine.

Chondrocyte-based intraoperative processing strategies for the biological augmentation of a polyurethane meniscus replacement.

Purpose/aim of study: Menisectomies account for over 1.5 million surgical interventions in Europe annually, and there is a growing interest in regenerative strategies to improve outcomes in meniscal replacement. The overall objective of this study was to evaluate the role of intraoperatively applied fresh chondrocyte (FC) isolates compared to minced cartilage (MC) fragments, used without cell isolation, to improve bioactivity and tissue integration when combined with a polyurethane replacement. MATERIALS AND METHODS: First, to optimize the intraoperative cell isolation protocol, caprine articular cartilage biopsies were digested with 750 U/ml or 3000 U/ml collagenase type II (ratio of 10 ml per g of tissue) for 30 min, 1 h or 12 h with constant agitation and compared to culture-expanded chondrocytes in terms of matrix deposition when cultured on polyurethane scaffolds. Finally, FCs and MC-augmented polyurethane scaffolds were evaluated in a caprine meniscal explant model to assess the potential enhancements on tissue integration strength. RESULTS: Adequate numbers of FCs were harvested using a 30 min chondrocyte isolation protocol and were found to demonstrate improved matrix deposition compared to standard culture-expanded cells in vitro. Upon evaluation in a meniscus explant defect model, both FCs and MC showed improved matrix deposition at the tissue-scaffold interface and enhanced push-out strength, fourfold and 2.5-fold, respectively, compared with the acellular implant. CONCLUSIONS: Herein, we have demonstrated a novel approach that could be applied intraoperatively, using FCs or MC for improved tissue integration with a polyurethane meniscal replacement.

IL-12 involvement in myogenic differentiation of C2C12 in vitro.

Recently, the extracellular microenvironment has been shown to be critical for the correct differentiation of stem cells to specific tissues. Many factors, including physical (e.g. biomaterial stiffness and topography) and biological (as growth factors, cytokines and chemokines) components, cooperate to create an ideal microenvironment for muscle stem cells, with many of these factors having been widely investigated. We previously demonstrated that the use of non-proliferating muscle-specific and unrelated cells as feeder layers for skeletal muscle progenitor cell differentiation resulted in significant differences in the ability to form myotubes, suggesting the importance of biological factors in myogenic differentiation. In this study, we investigated the biological factors involved in this process, analyzing the expression profile of 84 genes coding for cytokines and chemokines. We successfully identified a novel role for the cytokine IL-12 in the myogenic differentiation of C2C12 mouse skeletal muscle cells. Experiments involving the overexpression or silencing of the IL-12 gene in C2C12 showed that IL-12 enhanced the myogenic differentiation process. Moreover, when IL-12 was overexpressed in non-biologically related feeder cells, the new co-culture system was able to improve myogenic differentiation of C2C12 seeded on top. Although IL-12 is known to be a cytokine involved in inflammatory responses, it also appears to be involved in the myogenic differentiation process, acting as a positive regulator of this mechanism. This fact is expected to prove to be important for the development of functional biomaterials.

Hippo pathway effectors control cardiac progenitor cell fate by acting as dynamic sensors of substrate mechanics and nanostructure.

Stem cell responsiveness to extracellular matrix (ECM) composition and mechanical cues has been the subject of a number of investigations so far, yet the molecular mechanisms underlying stem cell mechano-biology still need full clarification. Here we demonstrate that the paralog proteins YAP and TAZ exert a crucial role in adult cardiac progenitor cell mechano-sensing and fate decision. Cardiac progenitors respond to dynamic modifications in substrate rigidity and nanopattern by promptly changing YAP/TAZ intracellular localization. We identify a novel activity of YAP and TAZ in the regulation of tubulogenesis in 3D environments and highlight a role for YAP/TAZ in cardiac progenitor proliferation and differentiation. Furthermore, we show that YAP/TAZ expression is triggered in the heart cells located at the infarct border zone. Our results suggest a fundamental role for the YAP/TAZ axis in the response of resident progenitor cells to the modifications in microenvironment nanostructure and mechanics, thereby contributing to the maintenance of myocardial homeostasis in the adult heart. These proteins are indicated as potential targets to control cardiac progenitor cell fate by materials design.

Adult stem cells and biocompatible scaffolds as smart drug delivery tools for cardiac tissue repair.

The contribution of adult stem cells to cardiac repair is mostly ascribed to an indirect paracrine effect, rather than to their actual engraftment and differentiation into new contractile and vascular cells. This effect consists in a direct reduction of host cell death, promotion of neovascularization, and in a "bystander effect" on local inflammation. A number of cytokines secreted by adult stem/progenitor cells has been proposed to be responsible for the consistent beneficial effect reported in the early attempts to deliver different stem cell subsets to the injured myocardium. Aiming to maximize their beneficial activity on the diseased myocardium, the genetic modification of adult stem cells to enhance and/or control the secretion of specific cytokines would turn them into active drug delivery vectors. On the other hand, engineering biocompatible scaffolds as to release paracrine factors could result in multiple advantages: (1) achieve a local controlled release of the drug of interest, thus minimizing off-target effects, (2) enhance stem cell retention in the injured area and (3) boost the beneficial paracrine effects exerted by adult stem cells on the host tissue. In the present review, a critical overview of the state-of-the-art in the modification of stem cells and the functionalization of biocompatible scaffolds to deliver beneficial soluble factors to the injured myocardium is offered. Besides the number of concerns to be addressed before a clinical application can be foreseen for such concepts, this path could translate into the generation of active scaffolds as smart cell and drug delivery systems for cardiac repair.