Accelerated stem cell attachment to ultrafine grained titanium

Commercial purity titanium with an average grain size in the low sub-micron range was produced by equal channel angular pressing (ECAP). Attachment of human bone marrow-derived mesenchymal stem cells (hMSCs) to the surface of conventional coarse grained and ECAP-modified titanium was studied. It was demonstrated that the attachment and spreading of hMSCs in the initial stages (up to 24h) of culture was enhanced by grain refinement. Surface characterization by a range of techniques showed that the main factor responsible for the observed acceleration of hMSC attachment and spreading on titanium due to grain refinement in the bulk is the attendant changes in surface topography on the nanoscale. These results indicate that, in addition to its superior mechanical properties, ECAP-modified titanium possesses improved biocompatibility, which makes it to a potent candidate for applications in medical implants.

Medical textiles as vascular implants and their success to mimic natural arteries

Vascular implants belong to a specialised class of medical textiles. The basic purpose of a vascular implant (graft and stent) is to act as an artificial conduit or substitute for a diseased artery. However, the long-term healing function depends on its ability to mimic the mechanical and biological behaviour of the artery. This requires a thorough understanding of the structure and function of an artery, which can then be translated into a synthetic structure based on the capabilities of the manufacturing method utilised. Common textile manufacturing techniques, such as weaving, knitting, braiding, and electrospinning, are frequently used to design vascular implants for research and commercial purposes for the past decades. However, the ability to match attributes of a vascular substitute to those of a native artery still remains a challenge. The synthetic implants have been found to cause disturbance in biological, biomechanical, and hemodynamic parameters at the implant site, which has been widely attributed to their structural design. In this work, we reviewed the design aspect of textile vascular implants and compared them to the structure of a natural artery as a basis for assessing the level of success as an implant. The outcome of this work is expected to encourage future design strategies for developing improved long lasting vascular implants.

3D fibrous structures as cardiovascular implants

Medical textiles are a highly specialised stream of technical textiles industry with a growing range of applications. A significant advancement has been achieved in surgical products or biomedical textiles (implantable/non-implantable) with the advent of 3D textile manufacturing techniques. Cardiovascular soft tissue implants (vascular grafts) have been a field of interest over decades for use of innovative 3D tubular structures in treatment of cardiovascular diseases. In the field of soft tissue implants, knitted and woven tubular structures are being used for large diameter blood vessel replacements. Advent of electrospinning and tissue engineering techniques has been able to provide promising answers to small diameter vascular grafts. The aim of this review is to outline the approaches in vascular graft development utilising different 3D tubular structure forming techniques. The emphasis is on vascular graft development techniques that can help improve treatment efficacy in future.

Simplifying medical additive manufacturing: making the surgeon the designer

Additive Manufacturing, a technology which has been in existence since three decades, is now successfully being transitioned from a research setting to finding technologically and financially viable end-user applications. A key sector in which Additive Manufacturing is being used is the medical devices and healthcare sector. Drivers in this sector include the ability to create customized, patient specific devices and implants with quick turnaround time in a cost-effective manner. Doctors and surgeons are important change agents and innovators in the creation of new healthcare devices as well as surgical methods. Often times, they may find it necessary at first to build devices and plan surgeries which are not even being thought of or acted upon by the major healthcare companies. In this sense, they perform the roles of designers, creating new ideas and improving on them until they can be implemented and adopted by others. However, the scope for performing this creative activity is often limited in their workplaces, with resource, time and financial impediments often being present. Additive Manufacturing can be helpful to speed up the iterative process of designing such medical devices or planning surgeries as well as help convince people outside of the surgery room of the feasibility and business case for such innovations. This paper proposes to introduce a framework of design, processes and tools which will enable non-engineers (specifically surgeons) to create custom-built products. It is hoped that this paper will motivate more surgeons and non-engineers to get involved in the process of designing for additive manufacturing.