Self-immolative Polymers Based Mixed Micelle Nano-assemblies

Abstract

Trigger dependent self-destructive scaffolds are emerging as hot domain in the research of biomaterials. Tailor-made zwitterionic systems comprising polycaprolactone and polypeptide frameworks have a wide range of structural tunability and biocompatibility; they are recently gaining importance in sectors such as drug, gene, and protein delivery. This thesis investigates the unique combination and stunning beauty of polylactones (ester linkage) and polypeptides (amide linkage), which have not been explored much in the literature. Here mixed micelle architecture of amphiphiles containing diblock polymers is endowed. Combining two different amphiphiles together in a mixed micellar architecture helps to retain the properties of individual amphiphiles and adds some additional value to the system. Stabilizing the unstable poly amino ester at the physiological pH = 7.4 is the real motive; here, it is achieved by introducing a negatively charged stable counterpart, which anchors and balances the degradation of PAE. The synthesized polymers are characterized using 1H nuclear magnetic resonance spectroscopy (NMR), Matrix assisted laser desorption ionization (MALDI-TOF) for finding out the number of repeating units formed during polymerization. The progress of polypeptide reaction was continuously monitored using Fourier transform Infrared spectroscopy (FT-IR), Number average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity index (PDI) were determined by subjecting the synthesized polymers through size exclusion chromatography (SEC), the self assembled amphiphiles were analyzed to know surface charge using zeta potential and their size, morphology by dynamic light scattering (DLS). The thermal properties were analyzed by differential scanning calorimetry (DSC) to know glass transition temperature (Tg)and melting point (Tm) of different mono and di-block polymers. UV spectroscopy was used to study the transmittance to know the stability of the polymer at physiological pH, and also the drug (doxorubicin) and dye (Nile Red, Sulfonyl Rhodamine B, HPTS) loading capacity were evaluated through absorbance, to analyze the potential loading of the active compounds into the mixed micelle scaffold for human welfare.