Engineering a Titanium and Polycaprolactone Construct for a Biocompatible Interface Between the Body and Artificial Limb

Abstract

Intraosseous transcutaneous amputation prostheses may be able to overcome the problems that stem from the nonuniform distribution of pressure seen in the conventional stump-socket prosthetic replacement devices. Transcutaneous devices have had limited success in amputees. By optimizing the attachment of the skin to the prosthetic, intraosseous transcutaneous amputation prostheses may become clinically viable options. This report details studies evaluating the development of a modified titanium construct with a specially machined surface to increase the adherence of tissue as well as scaffold. A computer-aided biology tool was used to fabricate polycaprolactone (PCL) scaffolds with a specific three-dimensional architecture. To extrude the PCL, it was dissolved in acetic acid to produce a 70% PCL liquid. A scaffold with a porosity of >50% was fabricated to have a tensile strength similar to skin. The presence of a specially machined surface greatly increased the adhesion of the PCL scaffold to the titanium constructs. When the 70% PCL was properly neutralized by heating at 55 degrees C and washing in 90% ethanol (EtOH), there was only a decrease (10%) in the viability of cells seeded onto the PCL constructs when compared with the cells in culture. The antibacterial properties of titanium dioxide anatase, silver nanoparticles, and chlorhexidine diacetate mixed in either type I collagen or hyaluronic acid (HA) were assessed. The addition of 1% (w/w) chlorhexidine diacetate in HA resulted in a 71% decrease in bacteria seen in nontreated HA. These results show promise in developing a novel engineered titanium and PCL construct that promotes effective adhesion between the titanium-skin interface.

Dermal fibroblast and epidermal keratinocyte functionality on titania nanotube arrays

“…The passive oxide layer that forms on the outside surface of titanium, known as titania, protects the surface against corrosion while providing a favorable biocompatible interface for tissue integration [15,23]. Although these materials are among the better choices for transcutaneous implantable devices, all biomaterials have been shown to initiate biologic events in the form of inflammatory cell recruitment, granulation tissue formation, foreign body reaction and fibrosis [24,25]. These conditions may lead to poor skin-material integration, which is one of the major causes for the rejection of transcutaneous implantable devices [1,2,12].…”

Route-dependent systemic and local immune effects following exposure to solutions prepared from titanium dioxide nanoparticles

“…Another potential route of human exposure is parenteral following medical device implantation or in the future from tissue engineered products (Arys et al, 1998;Brien et al, 1992;Buly et al, 1992;Cunningham et al, 2002;Gerhardt et al, 2007;Miyauchi et al, 2010;Smith et al, 2010a). The daily consumption of nano-TiO 2 for adults is estimated to be &0.5-1.3 mg/kg/day, while children are believed to receive even greater doses (EFSA, 2004;Weir et al, 2012).…”

“…Titanium is often used in medical devices such as hip replacements and, over time, wear debris (small particles of titanium in the nano-to-micro-size range) can be released into the surrounding tissues and/or the bloodstream, resulting in parenteral exposure (Arys et al, 1998;Brien et al, 1992;Buly et al, 1992;Cunningham et al, 2002). Several groups have investigated nano-TiO 2 for use in bone tissue engineering applications, representing another possible route of parenteral exposure (Gerhardt et al, 2007;Miyauchi et al 2010;Smith et al 2010a). In 2006, the International Agency for Research on Cancer (IARC) classified all forms of titanium dioxide as possibly carcinogenic to humans (Class 2B) on the basis of animal carcinogenicity data from inhalation studies, even though in vitro genotoxicity and carcinogenicity after oral exposure in B 6 C 3 F 1 mice and F344 rats were negative (Ashby & Tennant, 1991;IARC, 2006;NCI, 1979;Shelby, 1988;Shelby & Zeiger, 1990;Witt et al, 2000).…”

Progress in organ 3D bioprinting

“…In 2008, Kouhi et al at Australia Swinburne University of Technology prepared a P400ABS plastic jawbone by fused deposition manufacturing [66] . In 2010, Smith et al at nScrypt company in Orlando produced a hard tissue repair material using titanium and caprolactone [67] . In the same way, Lee et al printed a porous calcium phosphate cement/alginate scaffold by depositing a solution of α-tricalcium phosphate-based powder and sodium alginate in a calcium chloride bath [68] .…”