Design and fabrication of novel polymeric biodegradable stents for small caliber blood vessels by computer-aided wet-spinning

Abstract

Biodegradable stents have emerged as one of the most promising approaches in obstructive cardiovascular disease treatment due to their potential in providing mechanical support while it is needed and then leaving behind only the healed natural vessel. The aim of this study was to develop polymeric biodegradable stents for application in small caliber blood vessels. Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (PHBHHx), a renewable microbial aliphatic polyester, and poly(ε-caprolactone), a synthetic polyester approved by the US Food and Drug Administration for different biomedical applications, were investigated as suitable polymers for stent development. A novel manufacturing approach based on computer-aided wet-spinning of a polymeric solution was developed to fabricate polymeric stents. By tuning the fabrication parameters, it was possible to develop stents with different morphological characteristics (e.g. pore size and wall thickness). Thermal analysis results suggested that material processing did not cause changes in the molecular structure of the polymers. PHBHHx stents demonstrated great radial elasticity while PCL stents showed higher axial and radial mechanical strength. The developed stents resulted able to sustain proliferation of human umbilical vein endothelial cells within two weeks of in vitro culture and they showed excellent results in terms of thromboresistivity when in contact with human blood.

The Comprehensive Approach to Preparation and Investigation of the Eu3+ Doped Hydroxyapatite/poly(L-lactide) Nanocomposites: Promising Materials for Theranostics Application

“…The biocompatible and biodegradable poly(L-lactide) is one of the most popular polymers produced from renewable raw materials [3]. It can enhance the adhesion and elasticity of composite materials, therefore, it is broadly used in medical and biomedical applications, i.e., for vascular stent production [4], for drug delivery systems [5], for tissue engineering [6], and as surgical sutures, implants and screws. Moreover, it is used in such fields as water purification by oil adsorption [7,8], food packaging [9] or photocatalysis degradation [10].…”

Biodegradable and Biocompatible Polyhydroxy-alkanoates (PHA): Auspicious Microbial Macromolecules for Pharmaceutical and Therapeutic Applications

“…PHBHHx stents revealed outstanding radial elasticity, while higher axial and radial mechanical strength was measured for PCL stents. In two weeks in vitro cultures, the new stents sustained proliferation of human umbilical vein endothelial cells; moreover, the stents showed exceptional thromboresistivity in contact with human blood [ 76 ]. Further in vitro investigation studies performed by the same group of authors revealed that PHBHHx/PCL blend scaffolds, manufactured by computer-aided wet-spinning from solutions of PHBHHx and PCL in THF, can sustain adhesion and proliferation of MC3T3-E1 murine pre-osteoblast cells [ 77 ].…”

Biomedical Processing of Polyhydroxyalkanoates

“…This kind of PHBHHx scaffolds, possibly in the form of a blend with PCL [101], were demonstrated to sustain the in vitro adhesion and proliferation of MC3T3-E1 murine preosteoblast cells. CAWS approach was also recently implemented with a rotating mandrel, as a fiber collector during polymer coagulation, to fabricate small-caliber biodegradable stents made of either PHBHHx or PCL [102]. Tubular constructs with different porous architectures were developed by controlling the synchronized motion of the deposition needle and the rotating mandrel.…”