<italic>In vivo</italic> study on the histocompatibility and degradation behavior of biodegradable poly(trimethylene carbonate-co-d,l-lactide)

Abstract

The aim of this study was to explore the in vivo behavior and histocompatibility of poly(trimethylene carbonateco-D,L-lactide) (PDLLA/TMC) and its feasibility of manufacturing cardiovascular stents. Copolymers with 50/50 molar ratio were synthesized by ring-opening polymerization with TMC and D, L-LA, or TMC and L-LA. Poly (L-lactide) (PLLA) was synthesized as a control. The films of the three polymers were implanted into 144 Wistar rats. At different time points of implantation, polymer films were explanted for the evaluation of degradation characteristics and histocompatibility using size exclusion chromatography , nuclear magnetic resonance , environmental scanning electron microscope , and optical microscope. Results showed that there were differences in the percentage of mass loss, molecular weight, shape and appearance changes, and inflammation cell counts between different polymers. With the time extended, the film's superficial structure transformed variously, which was rather obvious in the polymer of PDLLA/TMC. In addition, there were relatively lower inflammation cell counts in the PDLLA/TMC and poly(trimethylene carbonate-co-L-lactide) (PLLA/TMC) groups at different time points in comparison with those in the PLLA group. The differences were of statistical significance (P < 0.05) in the group of PDLLA/TMC vs. PLLA, and the group of PLLA/TMC vs. PLLA, but not within the PDLLA/TMC and PLLA/TMC groups (P > 0.05). These results suggested that the polymer of PDLLA/TMC (50/50) with favorable degradation performance and histocompatibility is fully biodegradable and suitable for manufacturing implanted cardiovascular stents.

In vitro and in vivo degradation behavior of poly(trimethylene carbonate-co-d,l-lactic acid) copolymer

“…Other than the ‘bulk degradation mode’ of PDLLA, PTMC has been shown to degrade by surface erosion approach [ 18 , 19 ], avoiding the sharp attenuation of mechanical strength during fragmentation of the matrix. In addition, PDLLA cleaves by hydrolysis into acidulous lactic acid [ 20 , 21 ], which has an adverse effect on surrounding tissue. It has been demonstrated that enzymes and reactive oxygen species secreted by phagocytic cells play an important role in the in vivo degradation of PTMC [ 22 , 23 ], and it degrades without the formation of acidic compounds, which is an advantage as regenerative material.…”

In vivo degradation of poly L-lactic D-lactic acid and tri-methylene carbonate sheets in orbital reconstruction

“…Beyond 60 days, the molecular weight of PDLLA-TMC decreased below 10,000 kDa, in agreement with the rapid mass loss observed in this period. [7] In our study, the weight average molecular weight (Mw) decreased from 151,000 to 10,000 Da.…”

“…Guo et al, [7] in an experiment using 144 Wistar rats, stated that the molecular weight of PLLA decreased rapidly, from 72,000 to 68,000 kDa in the first 2 days and to 32,000 kDa 15 days later. Similar molecular weight decreases were obtained for PLLA-TMC and PDLLA-TMC copolymers, although PLLA-TMC appeared more resistant to hydrolytic degradation.…”

Impact of Poly(L-lactide) versus Poly(L-Lactide-co-Trimethylene Carbonate) on Biological Characteristics of Fibroblasts and Osteoblasts*

“…One of the few studies in which immunological parameters were evaluated was performed in vivo and PLTMC/PLLA were implanted subcutaneously (GUO et al 2011). Fewer immune cells infiltrated tissues around PLTMC than in the PLLA implanted rats (GUO et al 2011).…”

“…One of the few studies in which immunological parameters were evaluated was performed in vivo and PLTMC/PLLA were implanted subcutaneously (GUO et al 2011). Fewer immune cells infiltrated tissues around PLTMC than in the PLLA implanted rats (GUO et al 2011). However, some macrophage infiltration was observed in a study in which the polymers were implanted into rat peritoneal cavity (DARGAVILLE et al 2011).…”