A Multilayer Functionalized Drug-Eluting Balloon for Treatment of Coronary Artery Disease

Combinatory Nanovesicle with siRNA-Loaded Extracellular Vesicle and IGF-1 for Osteoarthritis Treatments

Extracellular vesicles (EVs) have been found to have the characteristics of their parent cells. Based on the characteristics of these EVs, various studies on disease treatment using mesenchymal stem cell (MSC)-derived EVs with regenerative activity have been actively conducted. The therapeutic nature of MSC-derived EVs has been shown in several studies, but in recent years, there have been many efforts to functionalize EVs to give them more potent therapeutic effects. Strategies for functionalizing EVs include endogenous and exogenous methods. In this study, human umbilical cord MSC (UCMSC)-derived EVs were selected for optimum OA treatments with expectation via bioinformatics analysis based on antibody array. And we created a novel nanovesicle system called the IGF-si-EV, which has the properties of both cartilage regeneration and long-term retention in the lesion site, attaching positively charged insulin-like growth factor-1 (IGF-1) to the surface of the UCMSC-derived Evs carrying siRNA, which inhibits MMP13. The downregulation of inflammation-related cytokine (MMP13, NF-kB, and IL-6) and the upregulation of cartilage-regeneration-related factors (Col2, Acan) were achieved with IGF-si-EV. Moreover, the ability of IGF-si-EV to remain in the lesion site for a long time has been proven through an ex vivo system. Collectively, the final constructed IGF-si-EV can be proposed as an effective OA treatment through its successful MMP13 inhibition, chondroprotective effect, and cartilage adhesion ability. We also believe that this EV-based nanoparticle-manufacturing technology can be applied as a platform technology for various diseases.

Investigating Balloon-Vessel Contact Pressure Patterns in Angioplasty: In Silico Insights for Drug-Coated Balloons

Drug-Coated Balloons have shown promising results as a minimally invasive approach to treat stenotic arteries, but recent animal studies have revealed limited, non-uniform coating transfer onto the arterial lumen. In vitro data suggested that local coating transfer tracks the local Contact Pressure (CP) between the balloon and the endothelium. Therefore, this work aimed to investigate in silico how different interventional and device parameters may affect the spatial distribution of CP during the inflation of an angioplasty balloon within idealized vessels that resemble healthy femoral arteries in size and compliance. An angioplasty balloon computational model was developed, considering longitudinal non-uniform wall thickness, due to its forming process, and the folding procedure of the balloon. To identify the conditions leading to non-uniform CP, sensitivity finite element analyses were performed comparing different values for balloon working length, longitudinally varying wall thickness, friction coefficient on the balloon-vessel interface, vessel wall stiffness and thickness, and balloon-to-vessel diameter ratio. Findings indicate a significant irregularity of contact between the balloon and the vessel, mainly affected by the balloon's unfolding and longitudinal thickness variation. Mirroring published data on coating transfer distribution in animal studies, the interfacial CP distribution was maximal at the middle of the balloon treatment site, while exhibiting a circumferential pattern of linear peaks as a consequence of the particular balloon-vessel interaction during unfolding. A high ratio of balloon-to-vessel diameter, higher vessel stiffness, and thickness was found to increase significantly the amplitude and spatial distribution of the CP, while a higher friction coefficient at the balloon-to-vessel interface further exacerbated the non-uniformity of CP. Evaluation of balloon design effects revealed that the thicker tapered part caused CP reduction in the areas that interacted with the extremities of the balloon, whereas total length only weakly impacted the CP. Taken together, this study offers a deeper understanding of the factors influencing the irregularity of balloon-tissue contact, a key step toward uniformity in drug-coating transfer and potential clinical effectiveness.

Cleverballoon: An integrated approach for developing a drug-coated balloon with everolimus

Coronary artery disease (CAD) is a chronic disease associated with high mortality and morbidity. Although treatment with drug-eluting stents is the most frequent interventional approach for coronary artery disease, drug-coated balloons (DCBs) constitute an innovative alternative, especially in the presence of certain anatomical conditions in the local coronary vasculature. DCBs allow the fast and homogenous transfer of drugs into the arterial wall, during the balloon inflation. Their use has been established for treating in-stent restenosis caused by stent implantation, while recent clinical trials have shown a satisfactory efficacy in de novo small-vessel disease. Several factors affect DCBs performance including the catheter design, the drug dose and formulation. Cleverballoon focuses on the design and development of an innovative DCB with everolimus. For the realization of the development of this new DCB, an integrated approach, including in- vivo, in-vitro studies and in-silico modelling towards the DCB optimization, is presented.Clinical Relevance-The proposed study introduces the integration of in- vivo, in-vitro and in silico approaches in the design and development process of a new DCB, following the principles of 3R's for the replacement, reduction, and refinement of animal and clinical studies.

Endogenous stimulus-responsive nitric oxide releasing bioactive liposome for a multilayered drug-eluting balloon

Drug-eluting balloon (DEB) system has been widely utilized for percutaneous coronary intervention (PCI), treating atherosclerosis to overcome the limitations of cardiovascular stents. With the anti-proliferative drug, everolimus (EVL), nitric oxide (NO) plays a key bioregulator role to facilitate the angiogenesis of endothelial cells (ECs) and inhibit the cell proliferation of smooth muscle cells (SMCs) in the lesions of cardiovascular diseases. Due to the very short lifetime and limited exposure area of NO in the body, the continuous release and efficient delivery of NO must be carefully considered. In this respect, a liposome-containing disulfide bonding group was introduced as a delivery vehicle of EVL and NO with the continuous release of NO via successive reaction cycles with GSH and SNAP in the blood vessel without the need for exogenous stimulations. With a multilayer coating platform consisting of a polyvinylpyrrolidone (PVP)/EVL-laden liposome with NO (EVL-NO-Lipo)/PVP, we precluded the loss of the EVL-encapsulated liposome with NO release during the transition time and maximized the transfer rate from the surface of DEB to the tissues. The sustained release of NO was monitored using a nitric oxide analyzer (NOA), and the synergistic bioactivities of EVL and NO were proved in EC and SMC with angiogenesis and cell proliferation-related assays. From the results of hemocompatibility and ex vivo studies, the feasibility was provided for future in vivo applications of the multilayer-coated DEB system.

Reduced restenosis and enhanced re-endothelialization of functional biodegradable vascular scaffolds by everolimus and magnesium hydroxide

BACKGROUND

Coronary artery disease is a cardiovascular disease with a high mortality and mortality rate in modern society. Vascular stent insertion to restore blood flow is essential to treat this disease. A fully biodegradable vascular scaffold (BVS) is a vascular poly (L-lactic acid) (PLLA) stent that is receiving growing interest as this is biodegradable in the body and does not require secondary removal surgery. However, acidic byproducts composed of PLLA produced during the biodegradation of the BVS can induce an inflammatory response. Magnesium hydroxide, a basic inorganic particle, neutralizes the acidic byproducts of PLLA.  METHODS: In this study, we investigated using a BVS coated with everolimus and surface-modified magnesium hydroxide that suppresses smooth muscle cell proliferation and protects endothelial cells, respectively. The various characteristics of the functional stent were evaluated using in vitro and in vivo analyses.  RESULTS: The BVS was successfully prepared with evenly coated everolimus and surface-modified magnesium hydroxide. A neutral pH value was maintained by magnesium hydroxide during degradation, and everolimus was released for one month. The coated BVS effectively inhibited protein adsorption and platelet adhesion, demonstrating excellent blood compatibility. In vitro analysis showed that BVS protects endothelial cells with magnesium hydroxide and selectively inhibits smooth muscle cell proliferation via everolimus treatment. The functional BVS was inserted into porcine coronary arteries for 28 days, and the results demonstrated that the restenosis and inflammation greatly decreased and re-endothelialization was enhanced as compared to others.

CONCLUSIONS

This study provides new insights into the design of drug-incorporated BVS stent for coronary artery disease.

Comparison of Surface Functionalization of PLGA Composite to Immobilize Extracellular Vesicles

Endothelialization by materials provides a promising approach for the rapid re-endothelialization of a cardiovascular implantation. Although previous studies have focused on improving endothelialization through the immobilization of bioactive molecules onto the surface of biodegradable implants, comparative studies of effective surface modification have not yet been reported. Here, we conducted a comparative study on the surface modification of poly(lactide-co-glycolide) (PLGA)-based composites to graft mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) using three different materials, fibronectin (FN), polyethylenimine (PEI), and polydopamine (PDA), which have different bond strengths of ligand–receptor interaction, ionic bond, and covalent bond, respectively. Further in vitro analysis exhibited that MSC-EVs released from all modified films sustainably, but the MSC-EVs grafted onto the surface coated with PEI are more effective than other groups in increasing angiogenesis and reducing the inflammatory responses in endothelial cells. Therefore, the overall results demonstrated that PEI is a desirable coating reagent for the immobilization of MSC-EVs on the surface of biodegradable implants.