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Background Cataract surgery is a very popular operation that requires a postoperative period of frequent instillation of antibiotic and anti-inflammatory eye drops. Modified drug-eluting intraocular lenses (IOLs) may eliminate the need for eye drops after surgery. Aim The purpose of this study is to compare the morphological characteristics of dexamethasone eluting biodegradable polymeric thin films developed on the surface of commercially available IOLs by three different methods. Method This experimental study was conducted between May and August of 2021 in the Lab for Thin Films - Nanobiomaterials - Nanosystems & Nanometrology (LTFN) of the Aristotle University of Thessaloniki. A mixture of two organic polymers [Poly (D, L-lactide-co-glycolide)(PLGA), lactide: glycolide (75:25) and Polycaprolactone (PCL)] and dexamethasone was prepared and then deposited on the surface of three-piece IOLs by spin coating, by spray coating, and by gravure printing. The modified IOLs were sterilized with the use of ultraviolet (UV) radiation and plasma treatment. Their structural properties were studied with the use of atomic force microscopy (AFM). Results Spin coating and gravure printing produced uniform thin films on the surface of the IOLs which were not damaged during the sterilization process. Spray coating led to the partial coating of the surface of the IOLs; the thin films underwent alterations following plasma treatment. Conclusions Thin films developed by spin coating and gravure printing on IOLs demonstrate the desired morphological characteristics that make them suitable candidates for further research.

The possibility of replacing the damaged joint by an artificial (hip replacement) is one of the most important achievements of the orthopaedic science because it enables the person suffering from osteoarthritis to regain a normal life. However, infections that can be created after an implantation are one of the major complications that can lead to implant failure. Therefore, a preliminary study of vancomycin drug loaded Polycaprolactone (PCL) nanoparticles were created via Electrospraying Process, making it a promising nanovehicle to prevent and treat orthopedic implant-associated infections. Scanning Electron Microscopy (SEM) measurements confirmed the successful fabrication of these structures. Finally, drug release kinetics was established to observe the sustained release of the drug and degradation studies were performed in order to evaluate the mass loss of polymers.

Nowadays, the most common revascularization procedure to combat coronary artery disease is through Percutaneous Coronary Intervention (PCI) with the use of arterial stents. Two of the most recurrent drawbacks of stenting are restenosis and late stent thrombosis. To render the stent effective, a long-term antiplatelet drug delivery system have to be incorporated into a biodegradable polymer to target directly the malevolent site. A novel drug delivery nanosystem of Poly(D, L-lactic acid) (PLA) nanoparticles (NPs) loaded with Dipyridamole (DPM) was fabricated via electrospraying that forms monodispersed, biodegradable drug loaded NPs, as coating for cardiovascular stents. This study presents a feasible degradable NP delivery system that encapsulates, protects and controls the release of DPM, intended to reduce the possibility of thrombosis inside the stent.

There is, as a matter of fact, an ever increasing number of patients requiring total hip replacement (Pabinger, C.; Geissler, A. Osteoarthritis Cartilage 2014, 22, 734–741). Implant-associated acute inflammations after an invasive orthopedic surgery are one of the major causes of implant failure. In addition, there are instability, aseptic loosening, infection, metallosis and fracture (Melvin, J. S.; Karthikeyan, T.; Cope, R.; Fehring, T. K. J. Arthroplasty 2014, 29, 1285–1288). In this work, a drug-delivery nanoplatform system consisting of polymeric celluloce acetate (CA) scaffolds loaded with dexamethasone was fabricated through electrospinning. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) indicated the successful fabrication of these structures. Cytotoxicity studies were performed by using MTT assay, methylene-blue staining and SEM fixation and showed very good cell adhesion and proliferation, indicating the cytocompatibility of these fibrous scaffolds. Drug-release kinetics was measured for the evaluation of a controllable and sustained release of anti-inflammatory drug onto the engineered implants and degradation study was conducted in order to assess the mass loss of polymers. This drug-delivery nanoplatform as coating on titanium implants may be a promising approach not only to alleviate but also to prevent implant-associated acute inflammations along with a simultaneous controlled release of the drug.

Cardiovascular diseases constitute a major public health concern in industrialized nations. Oxidative stress induced free radicals play a critical role in cellular processes implicated in atherosclerosis and many other heart diseases. Quercetin (Qu) is an antioxidant drug which is shown that effectively protects against cardiovascular diseases (CVDs). Encapsulation of drugs in polymeric NPs are widely used in producing sustained and controllable drug release, or to avoid degradation of non-released drugs. In this current work, a novel system of polymeric PLGA NPs loaded with Qu, was fabricated via electrohydrodynamic atomization process (EHDA) in order to improve poor aqueous solubility and stability of the drug with the aim of preventing atherosclerosis. The fabricated nanoparticles collected in a stable glass substrate. The results of atomic force microscopy (AFM) analysis and the scanning electron microscope (SEM), confirmed the fabrication of spherical polymeric nanoparticles with diameter ranging from 300nm to350 nm, narrow size distribution and smooth surface. The release profile of quercetin from the particles was investigated by determining the drug amount released at specific intervals for by luminescence. Furthermore, XRD analysis was used to determine the physical status of Qu encapsulated in NPs compared with that of pure Qu. The information obtained from this study facilitates the design and fabrication of polymeric nanoparticles as possible delivery systems for encapsulation, protection and controlled release of the flavonoid quercetin which is aiming to protect against CVDs.

Milka Janjic,1,2 Foteini Pappa,1 Varvara Karagkiozaki,1 Christakis Gitas,2 Kiriakos Ktenidis,2 Stergios Logothetidis1 1Department of Physics, Laboratory for Thin Films – Nanosystems and Nanometrology, University of Thessaloniki, 2School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece Abstract: This study describes the development of drug-loaded nanofibrous scaffolds as a nanocoating for endovascular stents for the local and sustained delivery of rosuvastatin (Ros) and heparin (Hep) to injured artery walls after endovascular procedures via the electrospinning process.Purpose: The proposed hybrid covered stents can promote re-endothelialization; improve endothelial function; reduce inflammatory reaction; inhibit neointimal hyperplasia of the injured artery wall, due to well-known pleiotropic actions of Ros; and prevent adverse events such as in-stent restenosis (ISR) and stent thrombosis (ST), through the antithrombotic action of Hep.Methods: Biodegradable nanofibers were prepared by dissolving cellulose acetate (AC) and Ros in N,N-dimethylacetamide (DMAc) and acetone-based solvents. The polymeric solution was electrospun (e-spun) into drug-loaded AC nanofibers onto three different commercially available stents (Co–Cr stent, Ni–Ti stent, and stainless steel stent), resulting in nonwoven matrices of submicron-sized fibers. Accordingly, Hep solution was further used for fibrous coating onto the engineered Ros-loaded stent. The functional encapsulation of Ros and Hep drugs into polymeric scaffolds further underwent physicochemical analysis. Morphological characterization took place via scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses, while scaffolds’ wettability properties were obtained by contact angle (CA) measurements.Results: The morphology of the drug-loaded AC nanofibers was smooth, with an average diameter of 200–800nm, and after CA measurement, we concluded to the superhydrophobic nature of the engineered scaffolds. In vitro release rates of the pharmaceutical drugs were determined using a high-performance liquid chromatography assay, which showed that after the initial burst, drug release was controlled slowly by the degradation of the polymeric materials.Conclusion: These results imply that AC nanofibers encapsulated with Ros and Hep drugs have great potential in the development of endovascular grafts with anti-thrombogenic properties that can accelerate the re-endothelialization, reduce the neointimal hyperplasia and inflammatory reaction, and improve the endothelial function. Keywords: cardiovascular disease, stent, drug delivery, scaffolds, nanocoating

The number of patients in need of orthopaedic implants has increased rapidly over the past few years. Implant associated infections that are created after an invasive orthopaedic surgery are one of the major causes of implant failure. In this work, a drug delivery nano platform system was fabricated, consisted of Polycaprolactone (PCL) scaffolds loaded with the antibiotic drug vancomycin via Electrospinning process. Titanium implants’ surface has been modified with non-woven fibrous coatings while the efficacy and toxicity on fibroblasts were investigated in vitro. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) measurements showed the successful fabrication of those structures. Cytotoxicity studies took place in order to examine the cytocompatibilty of the nanoplatform. MTT assay and methylene blue staining showed an excellent cell adhesion and proliferation, thus enhance the cytocompatible behavior in vitro. Drug release kinetics further took place in line with degradation studies in order to evaluate the mass loss of polymers. This drug delivery nano platform is a promising nanovehicle to prevent and treat orthopedic implant-associated infections along with a simultaneously release of the drug in a controllable and sustainable manner.

Bacterial infections are a leading cause of death for millions of people worldwide, while few antibiotics have been proved effective against multidrug-resistant bacteria. Recently, nanoparticles have been used for the delivery of therapeutic agents to reduce bacterial infections due to their antimicrobial activity and unique mode of action. In our studies, silver nanoparticles (Ag NPs) have been used in order to meddle with associated infections for orthopaedic applications, due to their unique morphology and size. Nanoprecipitation method was used for the development of the NPs, using PVP (polyvinylpyrrolidone) as a reducing agent. Chitosan was used as a stabilizing and a coating agent at different concentrations (0.1%, 0.01% and 0.001%) in order to evaluate the most optimum capped coating. Atomic Force Microscopy (AFM) was the appropriate indicator for the morphological and topography analysis. Results showed that chitosan-capped NPs with 0.01% were found to be the most optimum. Transmittance measurements at plasmon emission at ∼320nm wavelength have showed Ag nanoparticles which were identified due to the sharp absorption peak. Variations of the absolute transmittance values due to the different thickness of the samples confirmed the coating of chitosan in Ag NPs. XRD measurements further took place and successfully have indicated the presence of chitosan in Ag nanoparticles’ surface. Electrospinning System was used for the formation of PCL (poly-e-caprolactone) scaffolds where Ag NPs were deposited via Electrospraying System. The final scaffolds were then studied with AFM and SEM (Scanning Electron Microscopy) Images. As a conclusion, the fabricated Ag NPs into polymer scaffolds appeared to be a valuable tool with antibacterial properties towards implant-associated orthopedic infections.

The purpose of the study was to appraise the effect of loading force magnitude on the determination of the elastic modulus of the anterior lens capsule through atomic force microscopy. Four human anterior lens capsules taken during phacoemulsification cataract surgery were studied, free of epithelial cells, with atomic force microscopy. For the experiment, five different indentation loading forces were applied to near areas of the specimen. Experimental data was exported and analyzed according to the Hertz model to obtain the Young's modulus with regards to the elastic behavior of the material. Force-distance curves were acquired by applying a load of 2, 5, 10, 20 and 30 nN. When examining the results it was evident that determination of Young's modulus of the anterior lens capsule is dependent on the loading force concerning the examined range. Loading forces of 10 and 20 nN led to results without significant difference (p > 0.05) and more reproducible (coefficients of variation 12.4 and 11.7 %, respectively).

Thromboembolic diseases constitute a plague in our century, wherein an imbalance of hemostasis leads to thrombus formation and vessels constriction reducing blood flow. Hence, the recent rise of nanomedicine gives birth to advanced diagnostic modalities and therapeutic agents for the early diagnosis and treatment of such diseases. Multimodal nanoagents for the detection of intravascular thrombi and nanovehicles for thrombus-targeted fibrinolytic therapy are few paradigms of nanomedicine approaches to overcome current diagnostic treatment roadblocks and persistent clinical needs. This review highlights the nanomedicine strategies to improve the imaging and therapy of acute thrombi by nanoparticles and nanotheranostics, the detailed imaging of thrombogenic proteins and platelets via atomic force microscopy with the knowledge basis of thrombosis pathophysiology and nanotoxicity., Lay abstract: The present review highlights the perspectives of nanomedicine in enhancing the diagnostic and therapeutic strategies to deal with thrombosis. The basics in thrombosis are highlighted to provide the reader with better comprehension of the application of nanotools and various multimodal nanocarriers for diagnosis, targeted therapy and monitoring of the disease. The visualization and treatment of acute thrombi using multifunctional nanoparticles and nanotheranostics, along with the structural investigation of the blood-clotting proteins exploiting the atomic force microscopy capabilities are comprehensively described. At the same time, toxicity and biocompatibility issues regarding nanoparticles are discussed.

Cardiovascular stents are commonly used for the treatment of cardiovascular diseases that in developed societies are the most frequent causes of mortality and morbidity. In recent years, thorough research and development of drug-eluting stents has been done, with emphasis on coronary stenting to avoid the most common complication, in-stent thrombosis. Dipyridamole (DPM) is a medication that inhibits blood clot formation. Drug delivery nanoplatforms consisting of biodegradable polymers can be fabricated via electrospinning deposition, known for its cost-effective and versatile advantages, that produces fibrous scaffolds that are able to sustain and control drug release. A novel drug delivery nanosystem of polylactic acid fibrous scaffold loaded with the anti-platelet drug DPM was fabricated by electrospinning as coating for cardiovascular stents. The surface morphology and topography that were evaluated via atomic force microscopy, scanning electron microscopy and optical microscopy, were found to be good and suitable for tissue engineering. Contact angle measurements established the hydrophobic behavior of these fibrous nanoplatforms. Drug-release kinetics and degradation studies were conducted and revealed a sustained and controllable release of DPM, through this fibrous matrix over time. Finally, cytotoxicity studies took place to evaluate the cytocompatibility of the scaffold that confirmed its compatible behavior. The successful performance of this nanoplatform can lead to it being a valuable tool for atherosclerosis treatment.

Varvara C Karagkiozaki1,2, Stergios D Logothetidis2, Spyridon N Kassavetis2, George D Giannoglou11Aristotle University of Thessaloniki, Medical School, AHE PA University General Hospital, 1st Cardiology Department, Cardiovascular Engineering and Atherosclerosis Laboratory, Greece; 2Aristotle University of Thessaloniki, Physics Department, Laboratory for Thin Films – Nanosystems and Nanometrology (LTFN), GreeceAbstract: The treatment of patients with drug-eluting stents (DES) continues to evolve with the current emergence of DES technology that offers a combination of pharmacological and mechanical approaches to prevent arterial restenosis. However, despite the promising short-term and mid-term outcomes of DES, there are valid concerns about adverse clinical effects of late stent thrombosis. In this study, we present an example of how nanomedicine can offer solutions for improving stent coating manufacturing, by producing nanomaterials with tailored and controllable properties. The study is based on the exploitation of human platelets response towards carbon-based nanocoatings via atomic force microscope (AFM). AFM can facilitate the comprehensive analysis of platelets behavior onto stent nanocoatings and enable the study of thrombogenicity. Platelet-rich plasma from healthy donors was used for the real-time study of biointerfacial interactions. The carbon nanomaterials were developed by rf magnetron sputtering technique under controllable deposition conditions to provide favorable surface nanotopography. It was shown that by altering the surface topography of nanocoatings, the activation of platelets can be affected, while the carbon nanocoatings having higher surface roughness were found to be less thrombogenic in terms of platelets adhesion. This is an actual solution for improving the stent coating fabrication.Keywords: stents nanomedicine, carbon coating, atomic force microscopy platelets nanotechnology

Atherosclerosis is a multifactorial disease and many different approaches have been attempted for its accurate diagnosis and treatment. The disease is induced by a low-grade inflammatory process in the vascular wall, leading through a cascade of events to the eventual formation of atheromatous plaque and arterial stenosis. Different types of cells participate in the process making more difficult to recognize the potential cellular targets within the plaques for their effective treatment. The rise of nanomedicine over the last decade has provided new types of drug delivery nanosystems that are able to be delivered to a specific diseased site of the vessel for imaging while simultaneously act as therapeutic agents. In this paper, a review of the recent advances in nanomedicine that has provided novel insights to the disease diagnosis and treatment will be given in line with different nanotechnology-based approaches to advance the cardiovascular stents. The main complications of bare metal stents such as restenosis and of drug-eluting stents which is the late stent thrombosis are analyzed to comprehend the demand for emerging therapeutic strategies based on nanotechnology.

This report characterizes renal dysfunction after total cavopulmonary (TCPC) revision surgery for atriopulmonary Fontan (APF) circulations, a known risk factor for a poor outcome. The perioperative data for 23 consecutively identified patients were reviewed. The preoperative mean glomerular filtration rate (GFR) was 101 +/- 30 ml/min/1.73 m(2), decreasing to 65 +/- 41 ml/min/1.73 m(2) early in the postoperative period. The preoperative GFR was highly correlated with age at APF (r = -0.5; p = 0.024), age at TCPC (r = -0.5; p = 0.01), and mixed venous saturation (r = 0.6; p = 0.01). Three of four patients requiring renal replacement therapy (RRT) died at a median age of 3 months (range, 18 days to 9 months). Determinants of early GFR and RRT were preoperative GFR (p = 0.016) and creatinine (p = 0.035). Younger age at primary Fontan (p = 0.008), higher preoperative mixed venous saturation (p = 0.019), and higher preoperative blood pressure (p = 0.006) independently predicted better GFRs at the latest follow-up evaluation. Renal function declines acutely after TCPC revision, often necessitating RRT. A requirement for RRT marks greater mortality. Higher preoperative creatinine levels identify those at greatest risk.