A Nontoxic Additive to Introduce X‐Ray Contrast into Poly(Lactic Acid). Implications for Transient Medical Implants Such as Bioresorbable Coronary Vascular Scaffolds

Abstract

Bioresorbable coronary vascular scaffolds are about to revolutionize the landscape of interventional cardiology. These scaffolds, consisting of a poly(L-lactic acid) interior and a poly(D,L-lactic acid) surface coating, offer a genuine alternative for metallic coronary stents. Perhaps the only remaining drawback is that monitoring during implantation is limited to two X-ray contrast points. Here, a new approach to make the biodegradable scaffolds entirely radiopaque is explored. A new contrast agent is designed and synthesized. This compound is miscible with poly(D,L-lactic acid) matrix, and nontoxic to multiple cell types. Blends of poly(D,L-lactic acid) and the contrast agent are found to be hemocompatible, noncytotoxic, and radiopaque. The data show that it is possible to manufacture fully radiopaque bioresorbable coronary vascular scaffolds. Whole-stent X-ray visibility helps interventionalists ensure that the scaffold deploys completely. This important advantage may translate into improved safety, accuracy, and clinical performance of cardiac stents.

Fabrication, Characterization, and Properties of Poly (Ethylene-Co-Vinyl Acetate) Composite Thin Films Doped with Piezoelectric Nanofillers

“…Many biomedical devices lack radiopacity, making the visualization and assessment of material within the human body difficult. This may lead to a difficult evaluation of the nanocomposite material fate without using invasive methods [38].…”

Absorb bioresorbable stents for the treatment of coronary artery disease

“…Within 5 years, results from the randomized trials with the current Absorb stent -Absorb II, Absorb III, registration trials in USA, Japan and China and independent trials like AIDA and other will become available. The variety of available BRS lengths and sizes will certainly increase and the properties of polymer-based stents can be further improved, for example, a contrast agent can be blended with PLLA to improve radiopacity of the device [93]. Faster degradation of PLLA with lumen enlargement starting from 6 months can be achieved [94].…”

From in vitro evaluation to human postmortem pre-validation of a radiopaque and resorbable internal biliary stent for liver transplantation applications

“…To circumvent the problem of potential toxicity encountered with metallic additives [49], organic radiopacifiers containing heavy atoms such as bromine or iodine are also an option. However, the resulting polyester/radio-opacifier blends also suffer from leaching problems that result in the loss of imaging capabilities and potential toxicities [50]. To avoid leaching, two strategies have been described in the literature.…”