Cylindrical polyester/calcium peroxide oxygen-releasing microparticles: molecular dynamics simulation and experimental analyses

Peroxide salts are the in-situ oxygen generating components and can resolve the oxygen deficiency of the tissue engineering constructs. The type and properties of the polymeric carriers affect the release rate of the oxygen and peroxide reaction byproducts. In the present study, the composites including calcium peroxide (CPO) and different polyesters, i.e., PGA, PLA, and PCL were modeled with molecular dynamics (MD) simulation. The results of the simulation corroborated that diffusion coefficient of the molecules in PLA/CPO were intermediate between those of PGA/CPO and PCL/CPO composites. Therefore, PLA/CPO composite was fabricated with the combination of electrospinning and aminolysis methods for the experimental phase. The elemental analysis corroborated the uniform distribution of the CPO in microparticles and TGA results implied that composite microparticles were achieved with loading content and encapsulation efficiency of 2.92 and 73%, respectively. The evaluation of aminolysis time and PLA concentration implied that the aminolysis for 150 min produced microparticles with uniform shape. Moreover, the increase of PLA concentration from 6.5 to 13% (w/w) increased the average diameter and length of microparticles by 55 and 136%, respectively. The oxygen release measurement proved that microparticles with 13% PLA had the slowest release rate oxygen and the lowest burst release of it. [GRAPHICS] .

Automated summary

This study investigates the diffusion coefficients of different polyesters and calcium peroxide composites using molecular dynamics simulation. The PLA/CPO composite is prepared using electrospinning and aminolysis methods, and its elemental analysis and TGA results confirm the uniform distribution and loading efficiency of CPO. Evaluation of aminolysis time and PLA concentration reveals that 150 minutes of aminolysis and 13% PLA concentration result in uniformly shaped microparticles. Oxygen release measurement demonstrates that microparticles with 13% PLA exhibit the slowest release rate and lowest burst release.