Bioabsorption of polylactides with different molecular properties

Abstract

In order to study the effects of factors governing the bioabsorption rate of polylactides, implantation tests were carried out in rabbits using various samples (20 x 10 x 2 mm3) differing in their chemical composition, residual monomer content, and molecular orientation. Copolymer samples with a higher lactic acid content showed a lower rate of absorption, whereas those with a higher unreacted monomer content were absorbed faster and showed a more drastic decrease in molecular weight. In contrast, degradation of the purified polymers was slow; the purified poly-L-lactide showed no weight change and a 50% reduction in molecular weight after 6 months of implantation. Scanning electron microscopy of the samples containing monomers showed a microporous structure extending from the surface to the inner region a few days after implantation, whereas the purified poly-L-lactide did not exhibit a microporous structural change even after 10 months of implantation.

Polylactide/nano and microscale silica composite films. I. Preparation and characterization

“…[6][7][8][9][10][11][12] Nanocomposites are a class of composites in which dimensions of the reinforcing phase are in the order of nanometers. [13][14][15][16] Incorporation of nanoscale particles, especially SiO 2 , into PLA has been shown to improve its thermal stability, melt behavior, and mechanical properties. 15,16 SiO 2 particles are usually prepared by a sol-gel process, which consists of two steps: hydrolysis of a metal alkoxide and polycondensation of the hydrolysis products.…”

Cell colonization in degradable 3D porous matrices

“…Synthetic polyesters such as poly (lactic acid) (PLA), poly (glycolic acid) (PGA), their copolymers (PLGA, PLLA, etc. ), [62][63][64][65][66][67][68][69][70][71] and poly (caprolactone) (PCL) 72,73 have generated immense interest as tissue engineering materials. 74 Further information on specific 3D matrices can be found in a variety of review articles.…”

Tissue reaction and biodegradation of implanted cross‐linked high amylose starch in rats

“…Similarly in rabbits 19 and rats, 20 no differences in degradation were observed between subcutaneous and intramuscular polylactide implants. Because the inflammatory reaction at the sham site was short lived and minimal, the subcutaneous trauma caused by the surgery was not significant.…”