Low Dose of Ti3 C2 MXene Quantum Dots Mitigate SARS-CoV-2 Infection

MXene QDs (MQDs) have been effectively used in several fields of biomedical research. Considering the role of hyperactivation of immune system in infectious diseases, especially in COVID-19, MQDs stand as a potential candidate as a nanotherapeutic against viral infections. However, the efficacy of MQDs against SARS-CoV-2 infection has not been tested yet. In this study, Ti3 C2 MQDs are synthesized and their potential in mitigating SARS-CoV-2 infection is investigated.  Physicochemical characterization suggests that MQDs are enriched with abundance of bioactive functional groups such as oxygen, hydrogen, fluorine, and chlorine groups as well as surface titanium oxides. The efficacy of MQDs is tested in VeroE6 cells infected with SARS-CoV-2. These data demonstrate that the treatment with MQDs is able to mitigate multiplication of virus particles, only at very low doses such as 0,15 µg mL-1 . Furthermore, to understand the mechanisms of MQD-mediated anti-COVID properties, global proteomics analysis are performed and determined differentially expressed proteins between MQD-treated and untreated cells. Data reveal that MQDs interfere with the viral life cycle through different mechanisms including the Ca2 + signaling pathway, IFN-α response, virus internalization, replication, and translation. These findings suggest that MQDs can be employed to develop future immunoengineering-based nanotherapeutics strategies against SARS-CoV-2 and other viral infections.

Stem cells derived exosomes and biomaterials to modulate autophagy and mend broken hearts

Autophagy maintains cellular homeostasis and plays a crucial role in managing pathological conditions including ischemic myocardial injury leading to heart failure (HF). Despite treatments, no intervention can replace lost cardiomyocytes. Stem cell therapy offers potential for post-myocardial infarction repair but struggles with poor cell retention due to immune rejection. In the search for effective therapies, stem cell-derived extracellular vesicles (EVs), especially exosomes, have emerged as promising tools. These tiny bioactive molecule carriers play vital roles in intercellular communication and tissue engineering. They offer numerous therapeutic benefits including modulating immune responses, promoting tissue repair, and boosting angiogenesis. Additionally, biomaterials provide a conducive 3D microenvironment for cell, exosome, and biomolecule delivery, and enhance heart muscle strength, making it a comprehensive cardiac repair strategy. In this regard, the current review delves into the intricate application of extracellular vesicles (EVs) and biomaterials for managing autophagy in the heart muscle during cardiac injury. Central to our investigation is the exploration of how these elements interact within the context of cardiac repair and regeneration. Additionally, this review also casts light on the formidable challenges that plague this field, such as the issues of safety, efficacy, controlled delivery, and acceptance of these therapeutic strategies for effective clinical translation. Addressing these challenges is crucial for unlocking the full therapeutic potential of EV and biomaterial-based therapies and ensuring their successful translation from bench to bedside.

Immunoengineered MXene nanosystem for mitigation of alloantigen presentation and prevention of transplant vasculopathy

MXenes are an emerging class of nanomaterials with significant potential for applications in nanomedicine. Amongst MXene technologies, titanium carbide (Ti₃C₂T_x) nanomaterials are the most mature and have received significant attention to tackle longstanding clinical challenges due to its tailored physical and material properties. Cardiac allograft vasculopathy is an aggressive form of atherosclerosis and a major cause of mortality among patients with heart transplants. Blood vessel endothelial cells (ECs) stimulate alloreactive T-lymphocytes to result in sustained inflammation. Herein, we report the first application of Ti₃C₂T_x MXene nanosheets for prevention of allograft vasculopathy. MXene nanosheets interacted with human ECs and downregulated the expression of genes involved in alloantigen presentation, and consequently reduced the activation of allogeneic lymphocytes. RNA-Seq analysis of lymphocytes showed that treatment with MXene downregulated genes responsible for transplant-induced T-cell activation, cell-mediated rejection, and development of allograft vasculopathy. In an in vivo rat model of allograft vasculopathy, treatment with MXene reduced lymphocyte infiltration and preserved medial smooth muscle cell integrity within transplanted aortic allografts. These findings highlight the potential of Ti₃C₂T_x MXene in treatment of allograft vasculopathy and inflammatory diseases.

Abstract P3064: Immunoengineered Tantalum Carbide Mxene Quantum Dots For Prevention Of Transplant Vasculopathy

Transplant vasculopathy is an aggressive form of atherosclerosis that manifests uniquely in transplanted hearts, lungs, and kidneys. Recently, immunoengineered transition metal carbides, or MXenes, have demonstrated unique immunomodulatory properties and this can potentially be leveraged to prevent transplant vasculopathy. Here, we present the synthesis, characterization and application of novel zero-dimensional tantalum carbide (Ta 4 C 3 T x ) MXene quantum dots (MQDs) for immunomodulation. A facile hydrofluoric acid-free etching protocol was developed to synthesize zero-dimensional Ta 4 C 3 T x MQDs from Ta 4 AlC 3 MAX phase. The resultant MQDs are 3 to 7 nm in diameter and are surface modified with carboxyl, hydroxyl, and amine functional groups for biological interactions. Immunomodulation was assessed in vitro through co-cultures of human umbilical vein endothelial cells (ECs) and peripheral blood mononuclear cells. We found that MQDs interact with activated human ECs in vitro to reduce activation and pro-inflammatory Th1 polarization of allogeneic CD4 + lymphocytes. Mechanistically, we showed using quantitative PCR that treatment with MQDs significantly increased endothelial surface expression of the T-cell co-inhibitory molecule PD-L1 and decreased the co-stimulatory molecule CD86. Furthermore, exploratory bulk RNA-sequencing of co-cultured lymphocytes showed decreases in the immunologic signatures of naïve T-cells and increases in the immunologic signatures of CD25 + regulatory T-cells, suggesting activation of this suppressive T-cell population. Finally, when applied in an in vivo rat model of transplant vasculopathy, treatment with MQDs reduced lymphocyte infiltration and preserved medial smooth muscle cell integrity within transplanted aortic segments. These findings suggest that these novel MQDs have potential as an effective treatment to ameliorate transplant vasculopathy.

Development of iPSC-based clinical trial selection platform for patients with ultrarare diseases

A "Leap-of-Faith" approach is used to treat patients with previously unknown ultrarare pathogenic mutations, often based on evidence from patients having dissimilar but more prevalent mutations. This uncertainty reflects the need to develop personalized prescreening platforms for these patients to assess drug efficacy before considering clinical trial enrollment. In this study, we report an 18-year-old patient with ultrarare Leigh-like syndrome. This patient had previously participated in two clinical trials with unfavorable responses. We established an induced pluripotent stem cell (iPSC)-based platform for this patient, and assessed the efficacy of a panel of drugs. The iPSC platform validated the safety and efficacy of the screened drugs. The efficacy of three of the screened drugs was also investigated in the patient. After 3 years of treatment, the drugs were effective in shifting the metabolic profile of this patient toward healthy control. Therefore, this personalized iPSC-based platform can act as a prescreening tool to help in decision-making with respect to patient's participation in future clinical trials.

Fabrication of Smart Tantalum Carbide MXene Quantum Dots with Intrinsic Immunomodulatory Properties for Treatment of Allograft Vasculopathy

MXene nanomaterials have sparked significant interest among interdisciplinary researchers to tackle today's medical challenges. In particular, colloidal MXene quantum dots (MQDs) offer the high specific surface area and compositional flexibility of MXene while providing improvements to aqueous stability and material-cell interactions. The current study for the first time reports the development and application of immunoengineered tantalum-carbide (Ta4C3T x ) MQDs for in vivo treatment of transplant vasculopathy. This report comes at a critical juncture in the field as poor long-term safety of other MXene compositions challenge the eventual clinical translatability of these materials. Using rational design and synthesis strategies, the Ta4C3T x MQDs leverage the intrinsic anti-inflammatory and antiapoptotic properties of tantalum to provide a novel nanoplatform for biomedical engineering. In particular, these MQDs are synthesized with high efficiency and purity using a facile hydrofluoric acid-free protocol and are enriched with different bioactive functional groups and stable surface TaO2 and Ta2O5. Furthermore, MQDs are spontaneously uptaken into antigen-presenting endothelial cells and alter surface receptor expression to reduce their activation of allogeneic T-lymphocytes. Finally, when applied in vivo, Ta4C3T x MQDs ameliorate the cellular and structural changes of early allograft vasculopathy. These findings highlight the robust potential of tailored Ta4C3T x MQDs for future applications in medicine.

Abstract P393: Fabrication Of Immunomodulatory Hydrogels For Cardiac Repair After Acute Myocardial Infaction

Introduction: The balance of pro- and anti-inflammatory processes is tightly linked to left ventricular remodeling after myocardial infarction. Immune activation also plays a key role in rejection of transplanted allogeneic stem cells. In this study, we present the design, fabrication and characterization of immunomodulatory chitosan-based hydrogels for cardiac repair after myocardial infarction.

Methods: Chitosan hydrogels conjugated with small immunomodulatory molecules were synthesized through a thermogelation process. Resultant hydrogels were characterized using scanning electron microscopy and Fourier-transformed infrared spectroscopy. Human mesenchymal stem cells were encapsulated into the hydrogels and biocompatibility was assessed after one week using fluorescence microscopy and a colorimetric assay. Immunomodulatory activity was assessed after co-culture with human T-lymphocytes using flow cytometry for CD4+IFN-γ+ pro-inflammatory and CD4+CD25+FoxP3+ regulatory T-lymphocytes.

Results: Small immunomodulatory molecules were successfully integrated into chitosan hydrogels. Physico-chemical characterization revealed no significant changes to the 3D structure and porosity of hydrogels. The addition of 10μM atorvastatin or 10μM rosuvastatin did not result in significant cytotoxicity to encapsulated mesenchymal stem cells at 3 or 7 days. Addition of statins resulted in marked suppression of CD4+ T-lymphocyte proliferation (Control 25.1 Fold, Atorvastatin 1.0 Fold, Rosuvastatin 2.3 Fold, p<0.001) and activation (CD4+IFN-γ+ Population: Control 87.1%, Rosuvastatin 23.7%, p<0.001) after stimulation. No differences were seen in percentages of CD4+CD25+FoxP3+ regulatory T-lymphocytes (Control 5.5%, Rosuvastatin 5.7%, ns).

Conclusion: A biocompatible immunomodulatory hydrogel was created through integration of atorvastatin and rosuvastatin into a chitosan hydrogel. Experiments are currently underway in vivo to examine its usefulness for stem cell delivery and reducing adverse left ventricular remodeling after myocardial infarction.

Carbon nanomaterials for cardiovascular theranostics: Promises and challenges

Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Heart attack and stroke cause irreversible tissue damage. The currently available treatment options are limited to "damage-control" rather than tissue repair. The recent advances in nanomaterials have offered novel approaches to restore tissue function after injury. In particular, carbon nanomaterials (CNMs) have shown significant promise to bridge the gap in clinical translation of biomaterial based therapies. This family of carbon allotropes (including graphenes, carbon nanotubes and fullerenes) have unique physiochemical properties, including exceptional mechanical strength, electrical conductivity, chemical behaviour, thermal stability and optical properties. These intrinsic properties make CNMs ideal materials for use in cardiovascular theranostics. This review is focused on recent efforts in the diagnosis and treatment of heart diseases using graphenes and carbon nanotubes. The first section introduces currently available derivatives of graphenes and carbon nanotubes and discusses some of the key characteristics of these materials. The second section covers their application in drug delivery, biosensors, tissue engineering and immunomodulation with a focus on cardiovascular applications. The final section discusses current shortcomings and limitations of CNMs in cardiovascular applications and reviews ongoing efforts to address these concerns and to bring CNMs from bench to bedside.

Application of injectable hydrogels for cardiac stem cell therapy and tissue engineering

Cardiovascular diseases are responsible for approximately one-third of deaths around the world. Among cardiovascular diseases, the largest single cause of death is ischemic heart disease. Ischemic heart disease typically manifests as progressive constriction of the coronary arteries, which obstructs blood flow to the heart and can ultimately lead to myocardial infarction. This adversely affects the structure and function of the heart. Conventional treatments lack the ability to treat the myocardium lost during an acute myocardial infarction. Stem cell therapy offers an excellent solution for myocardial regeneration. Stem cell sources such as adult stem cells, embryonic and induced pluripotent stem cells have been the focal point of research in cardiac tissue engineering. However, cell survival and engraftment post-transplantation are major limitations that must be addressed prior to widespread use of this technology. Recently, biomaterials have been introduced as 3D vehicles to facilitate stem cell transplantation into infarct sites. This has shown significant promise with improved cell survival after transplantation. In this review, we discuss the various injectable hydrogels that have been tried in cardiac tissue engineering. Exploring and optimizing these cell-material interactions will guide cardiac tissue engineering towards developing stem cell based functional 3D constructs for cardiac regeneration.