Elevated levels of reactive oxygen species play an integral role in chronic inflammation. Current treatments for chronic inflammation often ignore reactive oxygen species and instead focus on symptom control or immunosuppression. However, by controlling reactive oxygen species in inflammatory environments, cyclic inflammation can be reduced. Combining reactive oxygen species scavenging delivery systems with stealth coatings can help avoid the innate immune system and enable targeted delivery to sites of inflammation without causing further oxidative stress. For this purpose, poly(propylene sulfide) nanoparticles were synthesized utilizing two different surfactants, Pluronic F-127 and sucrose monolaurate, adding stealth properties to the coatings of the reactive oxygen species scavenging nanoparticles. Characterization of the nanoparticles demonstrated the surfactant coatings did not affect the scavenging abilities nor the cytocompatibility of the materials. Degradation of the nanoparticles related to the sulfide groups and disulfide bond interactions with reactive oxygen species was also analyzed. Moreover, proinflammatory cytokine secretion from macrophages exposed to the nanoparticles was investigated to determine immune response evasion. Results obtained showed little to no activation of macrophages exposed to nanoparticle formulations in regard to MCP-1 cytokine release. However, there is room for improvement using glycerol-based coatings with regard to protecting cells from reactive oxygen species exposure and reducing macrophage activation in relation to IL-6 and TNF-alpha. Overall, the nanoparticles investigated have the capabilities to improve inflammatory disease treatments by not only targeting delivery of therapeutics to the site of inflammation, but also avoiding excess immune response recruitment due to incorporation of stealth coatings.

The biomedical research of nucleic acids as therapeutics and their medical applications has been steadily progressing. Identifying the fundamental regulatory roles of nucleic acids and their potential use in the medical field is of major pursuit in current and future research endeavors. Research into nucleic acids for the treatment of vascular diseases has been an emerging avenue as nucleic acids have the ability to treat a variety of pathologies including atherosclerosis. A large part of the translational research in relation to nucleic acids is the development and optimization of drug delivery technologies that can harness the full potential of these molecules, providing untapped, novel therapeutic agents. Specifically, the use of biomaterial delivery systems, consisting of polymers, lipids, and inorganic materials, allows for the protection of nucleic acid therapeutics to promote targeting to regions of vascular damage. While the relevance of nucleic acid therapeutics has been well documented, their functionality for diseases affecting the peripheral vasculature, and the need for biomaterials systems capable of improving their efficacy, has been lacking. This review aims to provide an overview of the biomaterial technologies tested for nucleic acid delivery, relative to the science of applied vascular tissue engineering. The study of nucleic acids as therapeutic agents is rapidly advancing, with significant potential for treating diseases. These molecules play key roles in regulating biological processes and can be engineered for medical applications. One exciting area of research focuses on using nucleic acids to treat vascular diseases, such as atherosclerosis. To maximize their therapeutic impact, researchers are developing innovative delivery systems made from materials like polymers, lipids, and inorganic substances. These biomaterial-based carriers protect nucleic acids and target damaged blood vessels more effectively. This review highlights the latest biomaterial technologies in nucleic acid delivery and their role in vascular tissue repair. Future research will focus on refining biomaterial delivery systems to enhance the stability, targeting precision, and therapeutic efficacy of nucleic acid-based treatments. Efforts will also include exploring emerging materials, such as hybrid composites, and integrating advanced bioengineering approaches to address vascular diseases and other challenging medical conditions.

Hydrogels — water-insoluble, three-dimensional networks of polymer chains — are used as biomaterials in various biomedical and clinical applications. Their modularity and versatility have led to the development of increasingly complex hydrogels, which can dynamically respond to their environment, release drugs and regenerate cells and tissues. In this Review, we present a model-based modular hydrogel design framework that is application-driven and considers clinical translation early in the design process. In this approach, every component of the hydrogel formulation is optimized towards multifaceted design criteria of the target application, identifying how multiple properties can be integrated into a single formulation. We highlight the fundamental models of polymer physics that provide the basis of modular hydrogel design and examine how synthetic polymer precursors can be integrated to achieve such modularity. Finally, we discuss clinically approved hydrogel formulations, and investigate how challenges in clinical translation may be addressed by a modular design approach.

INTRODUCTION:Localized delivery of angiogenesis-promoting factors such as small molecules, nucleic acids, peptides, and proteins to promote the repair and regeneration of damaged tissues remains a challenge in vascular tissue engineering. Current delivery methods such as direct administration of therapeutics can fail to maintain the necessary sustained release profile and often rely on supraphysiologic doses to achieve the desired therapeutic effect. By implementing a microparticle delivery system, localized delivery can be coupled with sustained and controlled release to mitigate the risks involved with the high dosages currently required from direct therapeutic administration. METHODS:For this purpose, poly(lactic-co-glycolic acid) (PLGA) microparticles were fabricated via anti-solvent microencapsulation and the loading, release, and delivery of model angiogenic molecules, specifically a small molecule, nucleic acid, and protein, were assessed in vitro using microvascular fragments (MVFs). RESULTS:The microencapsulation approach utilized enabled rapid spherical particle formation and encapsulation of model drugs of different sizes, all in one method. The addition of a fibrin scaffold, required for the culture of the MVFs, reduced the initial burst of model drugs observed in release profiles from PLGA alone. Lastly, in vitro studies using MVFs demonstrated that higher concentrations of microparticles led to greater co-localization of the model therapeutic (miRNA) with MVFs, which is vital for targeted delivery methods. It was also found that the biodistribution of miRNA using the delivered microparticle system was enhanced compared to direct administration. CONCLUSION:Overall, PLGA microparticles, formulated and loaded with model therapeutic compounds in one step, resulted in improved biodistribution in a model of the vasculature leading to a future in translational revascularization.

Peripheral artery disease (PAD) is a disease of atherosclerosis in the lower extremities. PAD carries a massive burden worldwide, while diagnosis and treatment options are often lacking. One of the key points of research in recent years is the involvement of microRNAs (miRNAs), which are short 20-25 nucleotide single-stranded RNAs that can act as negative regulators of post-transcriptional gene expression. Many of these miRNAs have been discovered to be misregulated in PAD patients, suggesting a potential utility as biomarkers for PAD diagnosis. miRNAs have also been shown to play an important role in many different pathophysiological aspects involved in the initiation and progression of the disease including angiogenesis, hypoxia, inflammation, as well as other cellular functions like cell proliferation and migration. The research on miRNAs in PAD has the potential to lead to a whole new class of diagnostic tools and treatments.

Macroencapsulation has been widely used in cell therapy due to its capability to provide immune-privileged sites for implanted allogeneic or xenogeneic cells. Macroencapsulation also serves to provide mechanical and physiochemical support for maintaining cell expansion and promoting therapeutic functions. Macroencapsulation devices such as membrane-controlled release systems, hydrogels, microneedle (MN) array patches, and three-dimensional (3D) stents have shown promising in-lab and preclinical results in the maintenance of long-term cell survival and the strengthening of treatment efficacy. Recent studies focus on expanding the applications of these devices to new cell-based areas such as chimeric antigen receptor (CAR)-T cell delivery, cardiovascular disease therapy, and the exploration of new materials, construction methods, and working principles to augment treatment efficacy and prolong therapy duration. Here, we survey innovative platforms and approaches, as well as translation outcomes, for advancing the performance and applications of macrodevices for cell-based therapies. A discussion and critique regarding future opportunities and challenges is also provided.

PURPOSE: Peripheral artery disease (PAD) causes a myopathy in the lower extremity muscles, which contributes to patient functional disability. Although mitochondrial dysfunction promotes PAD muscle pathology, the underlying mechanisms are unclear. Recent studies note microRNA (miR)-210, a hypoxia-responsive negative regulator of mitochondrial respiration, is elevated in the blood of PAD patients. Thus, we compared miR-210 expression in skeletal muscle tissue of PAD patients versus non-PAD controls and its association to mitochondrial function and walking ability. The impact of revascularization on muscle miR-210 was also assessed. METHODS: Vascular surgeons at Baylor Scott and White Hospital and the University of Texas Health Science Center at San Antonio harvested gastrocnemius muscle biopsies from non-PAD controls (n = 8), intermittent claudication (IC) patients (n = 10 pre- and post-revascularization) and critical limb ischemia (CLI) patients (n = 12). Muscle miR-210 expression was analyzed by RT-PCR. High-resolution respirometry was used to measure muscle mitochondrial respiration. The six-minute walk test distance (6MWD) was used to assess walking ability. RESULTS: MiR-210 expression was elevated in IC (1.69 ± 0.64-fold, p = 0.14) and CLI (1.88 ± 0.71-fold, p = 0.02) muscle, and mitochondrial respiration was significantly lower during electron transport chain Complex II (p < 0.001 for IC and CLI) and Complex IV (IC: p = 0.04, CLI: p = 0.003), compared to non-PAD controls. MiR-210 expression was also negatively associated with Complex I (R2 = 0.21, p = 0.01), Complex I + II (R2 = 0.33, p = 0.001), and Complex IV respiration (R2 = 0.18, p = 0.01), as well as 6MWD (R2 = 0.57, p < 0.001). In IC patients, revascularization significantly reduced miR-210 expression (0.96 ± 0.19-fold, p < 0.001) and improved mitochondrial respiration of Complexes I + II and IV (p = 0.04), relative to pre-operative levels. CONCLUSION: MiR-210 expression is increased in PAD muscle and may be a critical link in PAD-associated reductions in mitochondrial respiration and walking ability. Thus, miR-210 may represent a novel diagnostic and prognostic biomarker for PAD myopathy, and a potential target for improving mitochondrial function and walking performance in PAD. Supported by NIH Grant R01AG064420.

One of the most widely spread vascular diseases worldwide and in the United States is Peripheral Arterial Disease The disease classification is based on clinical testing and the judgment of physicians. Our goal is to demonstrate the applicability of artificial neural networks as an objective diagnostic tool for medical use. Patients with Peripheral Arterial Disease have different levels of arterial damage, which results in a chronic lack of blood supply in the lower extremities. As a result, these patients develop structural changes in their tissues, with detrimental long-term effects. We are presenting the results obtained from the analysis of human muscle specimens, obtained from vascular patients, using several different convolution neural networks and transfer learning. We used the clinical classification standards to produce the labels for our dataset and we were able to successfully develop 11 different Artificial Neural Network Models for objective patient classification.

Postmenopausal osteoporosis results from a pro-resorptive bone environment, which decreases bone mineral density causing increased fracture risk. Bone marrow derived mesenchymal stem/stromal cells (MSCs) secrete factors involved in bone homeostasis, but osteoporosis mediated changes to their secretions remain understudied. Herein, we examined the secretome of MSCs isolated from ovariectomized rats (OVX rMSCs), a model of post-menopausal osteoporosis, as a function of cell-cell interactions. Specifically, we controlled clustering of OVX and SHAM rMSCs by assembling them in granular hydrogels synthesized from poly(ethylene glycol) microgels with average diameters of -10, 10 0, and 20 0 mu m. We directed both the sizes of rMSC clusters (single cells to -30 cells/cluster) and the percentages of cells within clusters ( -20-90%) by controlling the scaffold pore dimensions. Large clusters of OVX rMSCs had a pro-resorptive secretory profile, with increased concentrations of Activin A, CXCL1, CX3CL1, MCP-1, TIMP1, and TNF- alpha , compared to SHAM rMSCs. As this pro-resorptive bias was only observed in large cell clusters, we characterized the expression of several cadherins, mediators of cell-cell contacts. N-cadherin expression was elevated ( -4-fold) in OVX relative to SHAM rMSCs, in both cell clusters and single cells. Finally, TIMP-1 and MCP-1 secretion was only decreased in large cell clusters of OVX rMSCs when Ncadherin interactions were blocked, highlighting the dependence of OVX rMSC secretion of pro-resorptive cytokines on N-cadherin mediated cell-cell contacts. Further elucidation of the N-cadherin mediated osteoporotic MSC secretome may have implications for developing therapies for postmenopausal osteoporosis. Statement of significance Postmenopausal osteoporosis is a prevalent bone disorder that affects tens of millions of women worldwide. This disease is characterized by severe bone loss resulting from a pro-resorptive bone mar-row environment, where the rates of bone resorption outpace the rates of bone deposition. The paracrine factors secreted by bone marrow MSCs can influence cell types responsible for bone homeostasis, but the osteoporosis-mediated changes to MSC secretory properties remains understudied. In this study, we used PEG-based porous granular scaffolds to study the influence of cell clustering on the secretory prop-erties of osteoporotic MSCs. We observed increased secretion of several pro-resorptive factors by osteo-porotic MSCs in large clusters. Further, we explored the dependence of this altered secretion profile on N-cadherin mediated cell-cell contacts. Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Previous studies have demonstrated that circulating microRNA (miR)-210 levels are elevated in peripheral artery disease (PAD) patients. MiR-210 is known to be a negative regulator of mitochondrial respiration; however, the relationship between miR-210 and mitochondrial function has yet to be studied in PAD. We aimed to compare skeletal muscle miR-210 expression of PAD patients to non-PAD controls (CON) and to examine the relationship between miR-210 expression and mitochondrial function. Skeletal muscle biopsies from CON (n = 20), intermittent claudication (IC) patients (n = 20), and critical limb ischemia (CLI) patients (n = 20) were analyzed by high-resolution respirometry to measure mitochondrial respiration of permeabilized fibers. Samples were also analyzed for miR-210 expression by real-time PCR. MiR-210 expression was significantly elevated in IC and CLI muscle compared to CON (P = 0.008 and P < 0.001, respectively). Mitochondrial respiration of electron transport chain (ETC) Complexes II (P = 0.001) and IV (P < 0.001) were significantly reduced in IC patients. Further, CLI patients demonstrated significant reductions in respiration during Complexes I (state 2: P = 0.04, state 3: P = 0.003), combined I and II (P < 0.001), II (P < 0.001), and IV (P < 0.001). The expression of the miR-210 targets, cytochrome c oxidase assembly factor heme A: farnesyltransferase (COX10), and iron-sulfur cluster assembly enzyme (ISCU) were down-regulated in PAD muscle. MiR-210 may play a role in the cellular adaptation to hypoxia and may be involved in the metabolic myopathy associated with PAD.

mRNA vaccines have received major attention in the fight against COVID-19. Formulations from companies such as Moderna and BioNTech/Pfizer have allowed us to slowly ease the social distancing measures, mask requirements, and lockdowns that have been prevalent since early 2020. This past year's focused work on mRNA vaccines has catapulted this technology to the forefront of public awareness and additional research pursuits, thus leading to new potential for bionanotechnology principles to help drive further innovation using mRNA. In addition to alleviating the burden of COVID-19, mRNA vaccines could potentially provide long-term solutions all over the world for diseases ranging from influenza to AIDS. Herein, we provide a brief commentary based on the history and development of mRNA vaccines in the context of the COVID-19 pandemic. Furthermore, we address current research using the technology and future directions of mRNA vaccine research.

The therapeutic benefits of exogenously delivered mesenchymal stromal/stem cells (MSCs) have been largely attributed to their secretory properties. However, clinical translation of MSC-based therapies is hindered due to loss of MSC regenerative properties during large-scale expansion and low survival/retention post-delivery. These limitations might be overcome by designing hydrogel culture platforms to modulate the MSC microenvironment. Hydrogel systems could be engineered to i) promote MSC proliferation and maintain regenerative properties (i.e., stemness and secretion) during ex vivo expansion, ii) improve MSC survival, retention, and engraftment in vivo, and/or iii) direct the MSC secretory profile using tailored biochemical and biophysical cues. Herein, it is reviewed how hydrogel material properties (i.e., matrix modulus, viscoelasticity, dimensionality, cell adhesion, and porosity) influence MSC secretion, mediated through cell-matrix and cell-cell interactions. In addition, it is highlighted how biochemical cues (i.e., small molecules, peptides, and proteins) can improve and direct the MSC secretory profile. Last, the authors' perspective is provided on future work toward the understanding of how microenvironmental cues influence the MSC secretome, and designing the next generation of biomaterials, with optimized biophysical and biochemical cues, to direct the MSC secretory profile for improved clinical translation outcomes.

Although dry eye is highly prevalent, many challenges exist in diagnosing the symptom and related diseases. For this reason, anionic hydrogel-coated gold nanoshells (AuNSs) were used in the development of a label-free biosensor for detection of high isoelectric point tear biomarkers associated with dry eye. A custom, aldehyde-functionalized oligo(ethylene glycol)acrylate (Al-OEGA) was included in the hydrogel coating to enhance protein recognition through the formation of dynamic covalent (DC) imine bonds with solvent-accessible lysine residues present on the surface of select tear proteins. Our results demonstrated that hydrogel-coated AuNSs, composed of monomers that form ionic and DC bonds with select tear proteins, greatly enhance protein recognition due to changes in the maximum localized surface plasmon resonance wavelength exhibited by AuNSs in noncompetitive and competitive environments. Validation of the developed biosensor in commercially available pooled human tears revealed the potential for clinical translation to establish a method for dry eye diagnosis.

Storage and transportation of protein therapeutics using refrigeration is a costly process; a reliable electrical supply is vital, expensive equipment is needed, and unique transportation is required. Reducing the reliance on the cold chain would enable low-cost transportation and storage of biologics, ultimately improving accessibility of this class of therapeutics to patients in remote locations. Herein, we report on the synthesis of charged poly(N-isopropylacrylamide) nanogels that efficiently adsorb a range of different proteins of varying isoelectric points and molecular weights (e.g., adsorption capacity (Q) = 4.7 ± 0.2 mg/mg at 6 mg/mL initial IgG concentration), provide protection from external environmental factors (i.e., temperature), and subsequently release the proteins in an efficient manner (e.g., 100 ± 1% at 2 mg/mL initial IgG concentration). Both cationic and anionic nanogels were synthesized and selectively chosen based on the ability to form electrostatic interactions with adsorbed proteins (e.g., cationic nanogels adsorb low isoelectric point proteins whereas anionic nanogels adsorb high isoelectric point proteins). The nanogel-protein complex formed upon adsorption increases the stabilization of the protein's tertiary structure, providing protection against denaturation at elevated temperatures (e.g., 84 ± 4% of the protected IgG was stabilized when exposed to 65 °C). The addition of a high molar salt solution (e.g., 40 mM CaCl2 solution) to protein-laden nanogels disrupts the electrostatic interactions and collapses the nanogel, ultimately releasing the protein. The versatile materials utilized, in addition to the protein loading and release mechanisms described, provide a simple and efficient strategy to protect fragile biologics for their transport to remote areas without necessitating costly storage equipment.

The discovery of clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) genome editing systems and their applications in human health and medicine has heralded a new era of biotechnology. However, the delivery of CRISPR therapeutics is arguably the most difficult barrier to overcome for translation to in vivo clinical administration. Appropriate delivery methods are required to efficiently and selectively transport all gene editing components to specific target cells and tissues of interest, while minimizing off-target effects. To overcome this challenge, we discuss and critique nanoparticle delivery strategies, focusing on the use of lipid-based and polymeric-based matrices herein.

Recent advancements in molecular recognition have provided additional diagnostic and treatment approaches for multiple diseases, including autoimmune disorders and cancers. Research investigating how the composition of biological fluids is altered during disease progression, including differences in the expression of the small molecules, proteins, RNAs, and other components present in patient tears, saliva, blood, urine, or other fluids, has provided a wealth of potential candidates for early disease screening; however, adoption of biomarker screening into clinical settings has been challenged by the need for more robust, low-cost, and high-throughput assays. This review examines current approaches in molecular recognition and biosensing for the quantification of biomarkers for disease screening and diagnostic outcomes.

An aldehyde acrylate-based functional monomer was incorporated into poly(N-isopropylacrylamide-co-methacrylic acid) nanogels for use as protein receptors. The aldehyde component forms dynamic imines with surface exposed lysine residues, while carboxylic acid/carboxylate moieties form electrostatic interactions with high isoelectric point proteins. Together, these interactions effect protein adsorption and recognition.