Biocompatibility and biodegradation of polycaprolactone‐sebacic acid blended gels

Abstract

Tissue engineering aims at creating biological body parts as an alternative for transplanting tissues and organs. A current new approach for such materials consists in injectable biodegradable polymers. Their major advantages are the ability to fill-in defects, easy incorporation of therapeutic agents or cells, and the possibility of minimal invasive surgical procedures. Polycaprolactone (PCL) is a promising biodegradable and elastic biomaterial, with the drawback of low-degradation kinetics in vivo. In this work a biodegradable injectable gel of PCL blended with sebacic acid (SA) was prepared, to improve the degradation rate of the biomaterial. SA is known for its high degradation rate, although in high concentrations it could originate a pH decrease and thus disturb the biocompatibility of PCL. Degradation tests on phosphate buffered saline were carried out using 5% of SA on the blend and the biomaterial stability was evaluated after degradation using differential scanning calorimetry, dynamical mechanical analysis, and scanning electronic microscopy. After degradation the elastic properties of the blend decreased and the material became more crystalline and stiffer, although at a lower extent when compared with pure PCL. The blend also degraded faster with a loss of the crystalline phase on the beginning (30 days), although its thermal and mechanical properties remained comparable with those of the pure material, thus showing that it achieved the intended objectives. After cell assays the PCL-SA gel was shown to be cytocompatible and capable of maintaining high cell viability (over 90%).

Bilayer oxidized regenerated cellulose/poly ε-caprolactone knitted fabric-reinforced composite for use as an artificial dural substitute

“…The degradation of PCL is primarily caused by the hydrolytic cleavage of ester groups via surface erosion or bulk degradation pathways depending on diffusion-reaction phenomenon [39,40]. However, it was also shown that the degradation rate of materials varied and depended upon several factors including microstructure, macrostructure, molecular weight, environment and composition [21,41]. In this study, the faster degradation of ORC/PCL composites compared to the typical melt pressed PCL was a result of using highly absorbable ORC to rapidly produce large porous channels (50-800 microns) on composite layer side after its dissolution for ACSF to diffuse into the inner part of the composite and cause the bulk degradation to occur thoroughly.…”

Review on the current status of polymer degradation: a microbial approach

“…PCL depolymerases are also responsible for the degradation of polylcaprolactone (synthetic polymer) found in bacteria (Nishida and Tokiwa 1993;Suyama et al 1998). Blended PCLs have a greater degradation rate when employed with 5% sebacic acid (Salgado et al 2011;Tokiwa et al 2009). Fungi are widely reported for the biodegradation of PCL and hydrolysis.…”

A biocompatibility study of injectable poly(caprolactone-trifumarate) for use as a bone substitute material

“…However, this degradation process can take up to 2 years, which is a significant drawback clinically (Middleton & Tipton 2000). Various modifications, such as the addition of sebacic acid, have been reported to improve its degradation rate (Salgado et al 2012). Similarly, PCL can be modified by cross-linking a functional group such as fumarate, resulting in the synthesis of polycaprolactone fumarate (PCLF) (Wang et al 2009;Salgado et al 2012).…”

“…Various modifications, such as the addition of sebacic acid, have been reported to improve its degradation rate (Salgado et al 2012). Similarly, PCL can be modified by cross-linking a functional group such as fumarate, resulting in the synthesis of polycaprolactone fumarate (PCLF) (Wang et al 2009;Salgado et al 2012). However, this semi-crystalline product needs to be heated to a high temperature before it can be injected into any bone defect site.…”