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Stent malapposition is one of the most significant precursors of stent thrombosis and restenosis. Adverse haemodynamics may play a key role in establishing these diseases, although numerical studies have used idealised drug transport models to show that drug transport from malapposed drug-eluting stent struts can be significant. This paper aims to study whether drug transport from malapposed struts is truly significant. Another aim is to see whether a streamlined strut profile geometry – with a 61% smaller coating but a 32% greater coating-tissue contact area – can mitigate the adverse haemodynamics associated with stent malapposition while enhancing drug uptake.

Two- and three-dimensional computational fluid dynamics simulations were used in this study. Unlike past simulations of malapposed drug-eluting stent struts, a qualitatively validated drug-transport model which simulates the non-uniform depletion of drug within the drug coating was implemented.

It was shown that even a 10-µm gap between the strut and tissue dramatically reduces drug uptake after 24 h of simulated drug transport. Furthermore, the streamlined strut profile was shown to minimise the adverse haemodynamics of malapposed and well-apposed stent struts alike and enhance drug uptake.

Unlike prior numerical studies of malapposed stent struts, which did not model the depletion of drug in the drug coating, it was found that stent malapposition yields negligible drug uptake. The proposed semicircular-profiled strut was also shown to be advantageous from a haemodynamic and drug transport perspective.

The purpose of this paper is to fabricate pre-existing geometries of the stents using solvent cast 3D printing (SC3P) and encapsulation of each stent with heparin drug by using aminolysis reaction.

The iron pentacarbonyl powder and poly-ɛ-caprolactone blend (PCIP) were used to print stent designs of Art18z, Palmaz-Schatz and Abbott Bvs1.1. The properties of antithrombosis, anticoagulation and blood compatibility were introduced in the stents by conjugation of heparin drug via the aminolysis process. The aminolysis process was confirmed by energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy due to presence of amide group and nitrogen peak in the respective analysis. Biological studies were performed to depict the cell viability, hemocompatibility and antithrombotic properties. Besides, mechanical behaviors were analyzed to study the behavior of the stents under radial compression load and bending load.

The amount of heparin immobilized on the Art18z, Palmaz-Schatz and Abbott Bvs1.1 stents were 255 ± 27, 222 ± 30 and 212 ± 13 µg, respectively. The cell viability studies using L929 fibroblast cells confirmed the cytocompatibility of the stents. The heparinized SC3P printed stents displayed excellent thrombo-resistance, anticoagulation properties and hemocompatibility as confirmed by blood coagulation analysis, platelet adhesion test and hemolysis analysis. Besides, mechanical behavior was found in context of the real-life stents. All these assessments confirmed that the developed stents have the potential to be used in the real environment of coronary arteries.

Various customized shaped biodegradable stents were fabricated using 3D printing technique and encapsulated with heparin drug using aminolysis process.

The singularity of being the first Chinese manufacturer of drug-eluting stents to arrive in Brazil and the country being selected as the company's first experience outside its home country motivated the interest in the study of this case, vis-à-vis with the characteristic of internationalization medical device companies according to the Uppsala model. Considering this context, the following research question was outlined: “How did Microport internationalize before the distribution of its stents product in Brazil?” The aim of the study is to investigate Microport's internationalization process for the distribution of its drug-eluting stents in Brazil.

Exploratory research under the qualitative method was adopted. It chose the single case study as a procedure for data collection, as it is a revealing, exemplary subject that offers opportunities for access to unusual research. The company MicroPort was chosen because in the period when Chinese medical device companies were focused on gaining market share in China, MicroPort began its international expansion, choosing Brazil as the first country to have its own subsidiary. It consists in the case of the internationalization of a high-tech EMNE in an emerging country that has institutional and cultural differences.

Taking advantage of new technology in highly internationalized environments favors its insertion; the internationalization of medical technology can expand according to the Uppsala Model, which does not explain internationalization, but rather its evolution. Cultural and behavioral issues reinforce that the development of the market for medical devices depends on local perspectives and values. The formation of an ecosystem in the local market for internationalization is observed. One implication of the study is that MicroPort's experience and the application of the Uppsala model for international expansion can serve as an important learning experience for Brazilian multinational companies.

Empirical analysis carried out in the context of a single company. Although the results can be used as lessons learned from the application of the Uppsala model for international expansion of EMNE in an emerging market, caution should be exercised when generalizing its findings. Future studies could carry out comparative cases considering other emerging multinational companies, from the same sector or even from different industries, investing in other emerging markets. There is a limitation of the fact that the case studied does not explore the concepts of the later stages of the Uppsala model.

High-tech EMNEs internationalizing in other markets need to adopt aggressive strategies. The need to adopt different strategies for supply chain operations according to the specificities of the markets in which they operate. Important contributions to the Uppsala model, with regard to the process of passing stages, learning and networking. The findings of this study have similarities to the process described as a sequence of distinct phases of activities.

A local top management team is essential to deal with institutional issues of government agencies when EMNE is internationalized in a culturally distant market. When there are major institutional differences between the country of origin and the host country, the autonomy in the management of the foreign subsidiary positively influences the acceleration of the internationalization process of companies in the high-tech sector. When there are major institutional differences between the country of origin and the country of destination, the use of local social networks positively influences the acceleration of the internationalization process of companies in the high-technology sector.

Regardless of these limitations, the study provided an exciting case of internationalization of a Chinese company in Brazil operating in a high-tech medical sector. The challenges for the internationalization of EMNEs continue, which makes it opportune for future studies to include more research in this area. The propositions suggested in the study may be the first step.

There is widespread concern about low adherence to clinical practice guidelines (CPGs) and the low adoption of new medical technologies. To assist the regulatory response, we propose benchmarking clinical practice on the lower bound on the probability that a recommended treatment/new technology achieves a better outcome. This inequality–probability bound can be estimated from marginal outcome distributions. We illustrate the approach by comparing Swedish cardiologists' adoption of drug-eluting stents (DESs) with the inequality–probability bound on this technology improving outcomes. A substantial fraction of cardiologists are below the benchmark.

Additive manufacturing (AM), also known as three-dimensional (3D) printing technology, has been used in the health-care industry for over two decades. It is in high demand in the health-care industry due to its strength to manufacture custom-designed and personalized 3D constructs. Recently, AM technologies are being explored to develop personalized drug delivery systems, such as personalized oral dosages, implants and others due to their potential to design and develop systems with complex geometry and programmed controlled release profile. Furthermore, in 2015, the US Food and Drug Administration approved the first AM medication, Spritam® (Apprecia Pharmaceuticals) which has led to tremendous interest in exploring this technology as a bespoke solution for patient-specific drug delivery systems. The purpose of this study is to provide a comprehensive overview of AM technologies applied to the development of personalized drug delivery systems, including an analysis of the commercial status of AM based drugs and delivery devices.

This review paper provides a detailed understanding of how AM technologies are used to develop personalized drug delivery systems. Different AM technologies and how these technologies can be chosen for a specific drug delivery system are discussed. Different types of materials used to manufacture personalized drug delivery systems are also discussed here. Furthermore, recent preclinical and clinical trials are discussed. The challenges and future perceptions of personalized medicine and the clinical use of these systems are also discussed.

Substantial works are ongoing to develop personalized medicine using AM technologies. Understanding the regulatory requirements is needed to establish this area as a point-of-care solution for patients. Furthermore, scientists, engineers and regulatory agencies need to work closely to successfully translate the research efforts to clinics.

This review paper highlights the recent efforts of AM-based technologies in the field of personalized drug delivery systems with an insight into the possible future direction.