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Beta cell replacement has emerged as an attractive therapeutic alternative to traditional exogenous insulin administration for management of type 1 diabetes (T1D). Beta cells deliver insulin dynamically based on individual glycometabolic requirements, providing glycemic control while significantly reducing patient burden. Although transplantation into the portal circulation is clinically available, poor engraftment, low cell survival, and immune rejection have sparked investigation of alternative strategies for beta cell transplantation. In this review, we focus on current micro- and macroencapsulation technologies for beta cell transplantation and evaluate their advantages and challenges. Specifically, we comment on recent methods to ameliorate graft hypoxia including enhanced vascularization, reduction of pericapsular fibrotic overgrowth (PFO), and oxygen supplementation. We also discuss emerging beta cell-sourcing strategies to overcome donor shortage and provide insight into potential approaches to address outstanding challenges in the field.

Cell transplantation is a promising curative therapeutic strategy whereby impaired organ function can be restored without the need for whole-organ transplantation. A key challenge in allotransplantation is the requirement for life-long systemic immunosuppression to prevent rejection, which is associated with serious adverse effects such as increased risk of opportunistic infections and the development of neoplasms. This challenge underscores the urgent need for novel strategies to prevent graft rejection while abrogating toxicity-associated adverse events.We review recent advances in immunoengineering strategies for localized immunomodulation that aim to support allograft function and provide immune tolerance in a safe and effective manner.Immunoengineering strategies are tailored approaches for achieving immunomodulation of the transplant microenvironment. Biomaterials can be adapted for localized and controlled release of immunomodulatory agents, decreasing the effective dose threshold and frequency of administration. The future of transplant rejection management lies in the shift from systemic to local immunomodulation with suppression of effector and activation of regulatory T cells, to promote immune tolerance.

Pancreatic islet transplantation efficacy for type 1 diabetes (T1D) management is limited by hypoxia-related graft attrition and need for systemic immunosuppression. To overcome these challenges, we developed the Neovascularized Implantable Cell Homing and Encapsulation (NICHE) device, which integrates direct vascularization for facile mass transfer and localized immunosuppressant delivery for islet rejection prophylaxis. Here, we investigated NICHE efficacy for allogeneic islet transplantation and long-term diabetes reversal in an immunocompetent rat model. We demonstrated that polyamide is superior to resin for NICHE subQ integration and vascularization. We demonstrated allogeneic islets transplanted within pre-vascularized NICHE were engrafted, revascularized, and reverted diabetes in rats for over 150 days. Notably, we confirmed that localized immunosuppression prevented islet rejection without inducing toxicity or systemic immunosuppression. Moreover, for translatability efforts, we showed NICHE biocompatibility and feasibility of deployment, as well as short-term allogeneic islet engraftment in an MHC-mismatched nonhuman primate model. In sum, the NICHE is a safe and effective platform for islet transplantation and long-term T1D management.

Preexposure prophylaxis (PrEP) with antiretrovirals (ARV) can prevent human immunodeficiency virus (HIV) transmission, but its efficacy is highly dependent on strict patient adherence to daily dosing regimen. Long-acting (LA) ARV formulations or delivery systems that reduce dosing frequency may increase adherence and thus PrEP efficacy. While cabotegravir (CAB) long-acting injectable (CAB LA), an integrase strand transfer inhibitor (INSTI), reduces dosing frequency to bimonthly injections, variable pharmacokinetics (PK) between patients and various adverse reactions necessitate improvement in delivery methods. Here we developed a subcutaneously implantable nanofluidic device for the sustained delivery of CAB formulated with 2-hydroxypropyl-beta-cyclodextrin (beta CAB) and examined the pharmacokinetics (PK) in Sprague-Dawley rats for 3 months in comparison to CAB. Our study demonstrated beta CAB treatment group maintained clinically-relevant plasma CAB concentrations 2 times above the protein-adjusted concentration that inhibits viral replication by 90% (2xPA-IC90) and drug penetration into tissues relevant to HIV-1 transmission. Further, we successfully fitted plasma CAB concentrations into a PK model (R-2 = 0.9999) and determined CAB apparent elimination half-life of 47 days. Overall, our data shows the potential of sustained release of beta CAB via a nanofluidic implant for long-term PrEP delivery, warranting further investigation for efficacy against HIV infections.

Previously, we reported that post-translational modifications (PTMs) of MAGI1, including S741 phosphorylation and K931 de-SUMOylation, both of which are regulated by p90RSK activation, lead to endothelial cell (EC) activation. However, roles for p90RSK and MAGI1-PTMs in regulating EC permeability remain unclear despite MAGI1 being a junctional molecule. Here, we show that thrombin (Thb)-induced EC permeability, detected by the electric cell-substrate impedance sensing (ECIS) based system, was decreased by overexpression of dominant negative p90RSK or a MAGI1-S741A phosphorylation mutant, but was accelerated by overexpression of p90RSK, siRNA-mediated knockdown of magi1, or the MAGI1-K931R SUMOylation mutant. MAGI1 depletion also increased the mRNA and protein expression of the large tumor suppressor kinases 1 and 2 (LATS1/2), which inhibited YAP/TAZ activity and increased EC permeability. Because the endothelial barrier is a critical mediator of tumor hypoxia, we also evaluated the role of p90RSK activation in tumor vessel leakiness by using a relatively low dose of the p90RSK specific inhibitor, FMK-MEA. FMK-MEA significantly inhibited tumor vessel leakiness at a dose that does not affect morphology and growth of tumor vessels in vivo. These results provide novel insights into crucial roles for p90RSK-mediated MAGI1 PTMs and the Hippo pathway in EC permeability, as well as p90RSK activation in tumor vessel leakiness.

Purpose Mounting evidence demonstrates that combining radiation therapy (RT) with immunotherapy can reduce tumor burden in a subset of patients. However, conventional systemic delivery of immunotherapeutics is often associated with significant adverse effects, which force treatment cessation. The aim of this study was to investigate a minimally invasive therapeutics delivery approach to improve clinical response while attenuating toxicity. Methods and Materials We used a nanofluidic drug-eluting seed (NDES) for sustained intratumoral delivery of combinational antibodies CD40 and PDL1. To enhance immune and tumor response, we combined the NDES intratumoral platform with RT to treat the 4T1 murine model of advanced triple negative breast cancer. We compared the efficacy of NDES against intraperitoneal administration, which mimics conventional systemic treatment. Tumor growth was recorded, and local and systemic immune responses were assessed via imaging mass cytometry and flow cytometry. Livers and lungs were histologically analyzed for evaluation of toxicity and metastasis, respectively. Results The combination of RT and sustained intratumoral immunotherapy delivery of CD40 and PDL1 via NDES (NDES CD40/PDL1) showed an increase in both local and systemic immune response. In combination with RT, NDES CD40/PDL1 achieved significant tumor burden reduction and liver inflammation mitigation compared with systemic treatment. Importantly, our treatment strategy boosted the abscopal effect toward attenuating lung metastatic burden. Conclusions Overall, our study demonstrated superior efficacy of combination treatment with RT and sustained intratumoral immunotherapy via NDES, offering promise for improving therapeutic index and clinical response.

Cell encapsulation is an attractive transplantation strategy to treat endocrine disorders. Transplanted cells offer a dynamic and stimulus-responsive system that secretes therapeutics based on patient need. Despite significant advancements, a challenge in allogeneic cell encapsulation is maintaining sufficient oxygen and nutrient exchange, while providing protection from the host immune system. To this end, we developed a subcutaneously implantable dual-reservoir encapsulation system integrating in situ prevascularization and local immunosuppressant delivery, termed NICHE. NICHE structure is 3D-printed in biocompatible polyamide 2200 and comprises of independent cell and drug reservoirs separated by a nanoporous membrane for sustained local release of immunosuppressant. Here we present the development and characterization of NICHE, as well as efficacy validation for allogeneic cell transplantation in an immunocompetent rat model. We established biocompatibility and mechanical stability of NICHE. Further, NICHE vascularization was achieved with the aid of mesenchymal stem cells. Our study demonstrated sustained local elution of immunosuppressant (CTLA4Ig) into the cell reservoir protected transcutaneously-transplanted allogeneic Leydig cells from host immune destruction during a 31-day study, and reduced systemic drug exposure by 12-fold. In summary, NICHE is the first encapsulation platform achieving both in situ vascularization and immunosuppressant delivery, presenting a viable strategy for allogeneic cell transplantation.

The interplay among signaling events for endothelial cell (EC) senescence, apoptosis, and activation and how these pathological conditions promote atherosclerosis in the area exposed to disturbed flow (d-flow) in concert remain unclear. The aim of this study was to determine whether telomeric repeat-binding factor 2-interacting protein (TERF2IP), a member of the shelterin complex at the telomere, can regulate EC senescence, apoptosis, and activation simultaneously, and if so, by what molecular mechanisms. We found that d-flow induced p90RSK and TERF2IP interaction in a p90RSK kinase activity-dependent manner. An in vitro kinase assay revealed that p90RSK directly phosphorylated TERF2IP at the serine 205 (S205) residue, and d-flow increased TERF2IP S205 phosphorylation as well as EC senescence, apoptosis, and activation by activating p90RSK. TERF2IP phosphorylation was crucial for nuclear export of the TERF2IP-TRF2 complex, which led to EC activation by cytosolic TERF2IP-mediated NF-κB activation and also to senescence and apoptosis of ECs by depleting TRF2 from the nucleus. Lastly, using EC-specific TERF2IP-knockout (TERF2IP-KO) mice, we found that the depletion of TERF2IP inhibited d-flow-induced EC senescence, apoptosis, and activation, as well as atherosclerotic plaque formation. These findings demonstrate that TERF2IP is an important molecular switch that simultaneously accelerates EC senescence, apoptosis, and activation by S205 phosphorylation.

The current standard for cell encapsulation platforms is enveloping cells in semipermeable membranes that physically isolate transplanted cells from the host while allowing for oxygen and nutrient diffusion. However, long-term viability and function of encapsulated cells are compromised by insufficient oxygen and nutrient supply to the graft. To address this need, a strategy to achieve enhanced vascularization of a 3D-printed, polymeric cell encapsulation platform using platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs) is investigated. The study is conducted in rats and, for clinical translation relevance, in nonhuman primates (NHP). Devices filled with PRP, MSCs, or vehicle hydrogel are subcutaneously implanted in rats and NHP and the amount and maturity of penetrating blood vessels assessed via histopathological analysis. In rats, MSCs drive the strongest angiogenic response at early time points, with the highest vessel density and endothelial nitric oxide synthase (eNOS) expression. In NHP, PRP and MSCs result in similar vessel densities but incorporation of PRP ensues higher levels of eNOS expression. Overall, enrichment with PRP and MSCs yields extensive, mature vascularization of subcutaneous cell encapsulation devices. It is postulated that the individual properties of PRP and MSCs can be leveraged in a synergistic approach for maximal vascularization of cell encapsulation platforms.

The possible association between the membrane-associated guanylate kinase with inverted domain structure-1 (MAGI1) and inflammation has been suggested, but the molecular mechanisms underlying this link, especially during atherogenesis, remain unclear. In endothelial cells (ECs) exposed to disturbed flow (d-flow), p90 ribosomal S6 kinase (p90RSK) bound to MAGI1, causing MAGI1-S741 phosphorylation and sentrin/SUMO-specific protease 2 T368 phosphorylation-mediated MAGI1-K931 deSUMOylation. MAGI1-S741 phosphorylation upregulated EC activation via activating Rap1. MAGI1-K931 deSUMOylation induced both nuclear translocation of p90RSK-MAGI1 and ATF-6-MAGI1 complexes, which accelerated EC activation and apoptosis, respectively. Microarray screening revealed key roles for MAGI1 in the endoplasmic reticulum (ER) stress response. In this context, MAGI1 associated with activating transcription factor 6 (ATF-6). MAGI1 expression was upregulated in ECs and macrophages found in atherosclerotic-prone regions of mouse aortas as well as in the colonic epithelia and ECs of patients with inflammatory bowel disease. Further, reduced MAGI1 expression in Magi1(–/+) mice inhibited d-flow–induced atherogenesis. In sum, EC activation and ER stress–mediated apoptosis are regulated in concert by two different types of MAGI1 posttranslational modifications, elucidating attractive drug targets for chronic inflammatory disease, particularly atherosclerosis.

Spasticity is a severely debilitating condition where involuntary muscle contraction impedes normal movement, speech and gait. It usually results from motor root damage in patients with history of multiple sclerosis, traumatic brain injury, or stroke. This damage causes misfiring of neurons leading to erratic muscle contraction. Current treatments inhibit muscle activation, however, treatment is given upon onset of the spastic episode, delaying symptom alleviation. Here we developed a sensing device combining surface acoustic myography (sAMG) and surface electromyography (sEMG) for the automatic detection of spasticity. sAMG use acoustic-based sensors to detect pressure waves produced by muscle contraction whereas sEMG detect electrical signals from neuromuscular activity. Merging sEMG and sAMG sensors provided a robust set of spectral data to describe muscle contraction patterns in terms of electromechanical activities. Said patterns were used for calibration using machine-learning algorithms. With established normal patterns, the device can distinguish between voluntary and involuntary muscle movement. In sum, the symbiotic employment of both types of sensors shows potential in early detection of a spastic episode. Being able to detect the onset or to predict a spastic event can provide insight into the underlying physiological conditions and, ultimately, help develop technologies to mitigate its occurrence.

For over a century, a fundamental objective in infection biology research has been to understand the molecular processes contributing to the origin and perpetuation of epidemics. Divergent hypotheses have emerged concerning the extent to which environmental events or pathogen evolution dominates in these processes. Remarkably few studies bear on this important issue. Based on population pathogenomic analysis of 1200Streptococcus pyogenestypeemm89infection isolates, we report that a series of horizontal gene transfer events produced a new pathogenic genotype with increased ability to cause infection, leading to an epidemic wave of disease on at least two continents. In the aggregate, these and other genetic changes substantially remodeled the transcriptomes of the evolved progeny, causing extensive differential expression of virulence genes and altered pathogen:host interaction, including enhanced immune evasion. Our findings delineate the precise molecular genetic changes that occurred and enhance our understanding of the evolutionary processes that contribute to the emergence and persistence of epidemically successful pathogen clones. The data have significant implications for understanding bacterial epidemics and translational research efforts to blunt their detrimental effects.

For over a century, a fundamental objective in infection biology research has been to understand the molecular processes contributing to the origin and perpetuation of epidemics. Divergent hypotheses have emerged concerning the extent to which environmental events or pathogen evolution dominates in these processes. Remarkably few studies bear on this important issue. Based on population pathogenomic analysis of 1,200 Streptococcus pyogenes type emm89 infection isolates, we report that a series of horizontal gene transfer events produced a new pathogenic genotype with increased ability to cause infection, leading to an epidemic wave of disease on at least two continents. In the aggregate, these and other genetic changes substantially remodeled the transcriptomes of the evolved progeny, causing extensive differential expression of virulence genes and altered pathogen-host interaction, including enhanced immune evasion. Our findings delineate the precise molecular genetic changes that occurred and enhance our understanding of the evolutionary processes that contribute to the emergence and persistence of epidemically successful pathogen clones. The data have significant implications for understanding bacterial epidemics and for translational research efforts to blunt their detrimental effects., IMPORTANCE The confluence of studies of molecular events underlying pathogen strain emergence, evolutionary genetic processes mediating altered virulence, and epidemics is in its infancy. Although understanding these events is necessary to develop new or improved strategies to protect health, surprisingly few studies have addressed this issue, in particular, at the comprehensive population genomic level. Herein we establish that substantial remodeling of the transcriptome of the human-specific pathogen Streptococcus pyogenes by horizontal gene flow and other evolutionary genetic changes is a central factor in precipitating and perpetuating epidemic disease. The data unambiguously show that the key outcome of these molecular events is evolution of a new, more virulent pathogenic genotype. Our findings provide new understanding of epidemic disease.

The advances in biotechnology, biomechanics, and biomaterials can be used to develop organ models that aim to accurately emulate their natural counterparts. Heart disease, one of the leading causes of death in modern society, has attracted particular attention in the field of tissue engineering. To avoid incorrect prognosis of patients suffering from heart disease, or from adverse consequences of classical therapeutic approaches, as well as to address the shortage of heart donors, new solutions are urgently needed. Biotechnological advances in cardiac tissue engineering from a bioreactor perspective, in which recapitulation of functional, biochemical, and physiological characteristics of the cardiac tissue can be used to recreate its natural microenvironment, are reviewed. Detailed examples of functional and preclinical applications of engineered cardiac constructs and the state-of-the-art systems from a bioreactor perspective are provided. Finally, the current trends and future directions of the field for its translation to clinical settings are discussed.

Aims Ongoing inflammation and endothelial dysfunction occurs within the local microenvironment of heart failure, creating an appropriate scenario for successful use and delivery of nanovectors. This study sought to investigate whether cardiovascular cells associate, internalize, and traffic a nanoplatform called mesoporous silicon vector (MSV), and determine its intravenous accumulation in cardiac tissue in a murine model of heart failure. Methods and results In vitro cellular uptake and intracellular trafficking of MSVs was examined by scanning electron microscopy, confocal microscopy, time-lapse microscopy, and flow cytometry in cardiac myocytes, fibroblasts, smooth muscle cells, and endothelial cells. The MSVs were internalized within the first hours, and trafficked to perinuclear regions in all the cell lines. Cytotoxicity was investigated by annexin V and cell cycle assays. No significant evidence of toxicity was found. In vivo intravenous cardiac accumulation of MSVs was examined by high content fluorescence and confocal microscopy, with results showing increased accumulation of particles in failing hearts compared with normal hearts. Similar to observations in vitro, MSVs were able to associate, internalize, and traffic to the perinuclear region of cardiomyocytes in vivo. Conclusions Results show that MSVs associate, internalize, and traffic in cardiovascular cells without any significant toxicity. Furthermore, MSVs accumulate in failing myocardium after intravenous administration, reaching intracellular regions of the cardiomyocytes. These findings represent a novel avenue to develop nanotechnology-based therapeutics and diagnostics in heart failure.