Novel Technique Based on Fused Filament Fabrication (FFF) and Robocasting to Create Composite Medical Parts.

The purpose for this study is to obtain a new composite manufacturing system based on Additive Manufacturing techniques that allows the creation of parts for the medical industry. These pieces will be resistant, lightweight and may have geometries more complex than those created with traditional systems of composite material. The new system is based on the union of two heads on a 3D Rep-Rap printer. One of the heads is an extruder head of thermoplastic Fused Filament Fabrication (FFF) and the other is a dosing head, based on the Robocasting technique, designed to be assembled on the 3D printer. Thermoplastics material and epoxy resin will be used. The alternate printing of both materials generates a piece of composite material. This new technique will allow to increase the structural properties of the piece in the XY plane. The new additive manufacturing system allows to obtain mechanical improvements both in the modulus of elasticity and in the tensile strength. Increase the modulus of elasticity of a value between 50 and 80% depending on the thermoplastic filament used. In the same way the tensile strength has increased between 50 and 60%. The improvement in the strength / weight ratio allows to this new additive manufacturing system to create medical pieces in which the lightness and resistance are its main characteristic, such as orthopedic prostheses.The results show that the use of FFF together with Robocasting, as a manufacturing process for end-use parts, generates an additional advantage that had not been considered until now. The combination of a thermoplastic and an epoxy resin opens a new path in the additive manufacturing since it allows creating pieces with new qualities without being conditioned by the design.

Additive Manufacturing for Localized Medical Parts Production: A Case Study.

Centralized supply chains (SCs) are prone to disruption, which makes them a risky choice for medical equipment production. Additive manufacturing (AM) allows for production localization and improvements in SC resilience. However, the comparative competitiveness of a localized SC from the time and cost perspective is still unclear. In this study, we investigate the competitiveness of localized medical part AM SCs against centralized ones by analyzing the responsiveness and cost of each SC. We utilize a real-world case study in which an AM service provider supplies medical parts to university medical centers in the Netherlands to construct six scenarios. We also develop a thorough empirical cost formulation for both central and local AM of patient-specific medical parts. The results of scenario analysis show that when utilizing the currently available AM technology, localized SC configurations significantly reduce the delivery time from about 54 to 27h, but at a 4.3-fold higher cost. Hence, we illustrate that the cost difference between the localized and centralized scenarios can be reduced when state-of-the-art AM machines are utilized, demand volumes increase, and the distances between the SC network nodes expand. Moreover, our scenario analysis confirms that the cost of the measures taken to prevent dust dispersion associated with powder-bed fusion AM has a major impact on the total cost of localized AM SCs for medical parts. The results of this study contribute to the understanding of the relevant factors in deciding whether central or localized SC configurations can be used in the AM production of medical parts. Furthermore, this study provides managerial insights for decision-makers at governments and hospitals as well as AM service providers and AM equipment manufacturers.

Stems and leaves of Aconitum carmichaelii Debx. as potential herbal resources for treating rheumatoid arthritis: Chemical analysis, toxicity and activity evaluation.

According to folk usage of Aconitum carmichaelii Debx., the present study was designed to determine the feasibility of the stems and leaves of Aconitum carmichaelii Debx. as a new medicinal resource. Fourteen alkaloids in mother roots, fibrous roots, stems, and leaves of Aconitum carmichaelii Debx. were measured by HPLC-MS/MS. And multivariate analysis methods, such as clustering analysis and principal component analysis, were applied to analyze the difference among various parts. In addition, the acute toxicity, analgesia, and anti-inflammatory tests were carried out. The results suggested that the contents of alkaloids in mother roots and fibrous roots were approximate, but those of leaves and stems were different from mother roots and fibrous roots. The results of the acute toxicity testing demonstrated the toxicity of fibrous root was strongest, and mother roots were slightly less toxic than fibrous roots. The stems and leaves were far less toxic than mother and fibrous roots. In addition, the analgesia and inflammatory tests showed the effects of the various tissues had no difference each other. These results provided a basis for developing new complementary and alternative treatments for rheumatoid arthritis patients. Simultaneously, the approach may also turn wastes into treasure and promote the development of circular economy.