Based on the monomers used for the reaction, the polymers were categorized into three groups namely, poly(mannitol citric succinate) [p(MCSu)], poly (mannitol citric adipate) [p(MCA)], and poly(mannitol citric sebacate) [p(MCS)].
Figure 3a-c depicts the (1) H NMR spectra of representative p(MCD) polymers p(MCS)2, p(MCA)2, and p(MCSu)2, respectively.
It can be observed that the glass transition temperature of the polymers follows the order: p(MCS) < p(MCA) < p(MCSu).
The Young's modulus and TS of p(MCA)2 and p(MCSu)2 polymers were observed to be higher than other polymers in the respective group.
Similarly, the p(MCA) and p(MCSu) polymers exhibit the mechanical properties comparable with that of different tissues such as skin (27), cartilage (28) cardiovascular tissue (27), and, therefore, could be potentially developed for soft tissue-engineering applications.
Figure 6a-c represents the hydrolytic degradation profiles of the p(MCS), p(MCA), and p(MCSu) copolyesters, respectively.
The extent of degradation increased with pH, but the order of degradability remained the same, that is, p(MCSu)2 > p(MCA)2 > p(MCS).
The representative polymers p(MCS)2, p(MCA)2, and p(MCSu)2 were chosen to investigate the drug release characteristics of the p(MCD) copolyesters.
The release of the two dyes from p(MCA)2 and p(MCSu)2 was almost complete within a few hours, while the release of the dyes from p(MCS)2 occurred over days.