Biodegradable Polymers Derived from Amino Acids for Biological Applications

Abstract

Optically active α-hydroxy acids derived from amino acids have been synthesized and polymerized into new biodegradable polyesters. The variety of functional side chains enables the design of positively charged, negatively charged, hydrophobic and hydrophilic chiral building blocks or any combination of these constituents. Hydroxy acids of 15 natural amino acids were prepared with retention of configuration using a straightforward and reliable method of diazotization of α-amino acids. Polyesters were synthesized from these hydroxy acids by a number of methods: direct condensation in bulk, microwave assisted synthesis and ring opening polymerization. The molecular weight of the prepared polymers ranges between 2000 to 5000Da for the direct condensation and the microwave methods, whereas the ring opening polymerization results in high molecular weight polymers (20000 to 30000Da). The polymers were analyzed for their optical activity (Circular Dichroism Spectroscopy), thermal properties (DSC), solubility, molecular weight and polydispersity (GPC), and aqueous degradation. These polymers were tested for their compatibility to neuronal cells growth and differentiation.

Engineered Doxorubicin Delivery System Using Proteinoid-Poly (L-Lactic Acid) Polymeric Nanoparticles of Narrow Size Distribution and High Molecular Weight for Cancer Treatment

“…The accepted mechanism of this polymerization process is based on the role of lysine as a solvent for the other monomers, as it is condensed into the caprolactam under the high temperature conditions. The caprolactam initiates the polymerization with the rest of the present amino acids [15][16][17]22]. A brief schematic description of the polymerization process is shown in Figure 1.…”

Engineered Narrow Size Distribution High Molecular Weight Proteinoids, Proteinoid-Poly(L-Lactic Acid) Copolymers and Nano/Micro-Hollow Particles for Biomedical Applications

“…In general, such synthetic polymers may offer greater advantages over natural ones since they can be designed according to the desired use, providing a wide range of desired properties and predictable characteristics. Furthermore, synthetic polymers represent a reliable source of raw materials, free from concerns of infection or immunogenicity [9][10][11].…”

Microwave‐Assisted RAFT Polymerization

“…For many years, microwave heating has been employed to accelerate organic reactions involving small molecules while often simultaneously leading to a reduced occurrence of side reactions 21. Recently, the adoption of microwave heating techniques in polymer chemistry has facilitated rapid polymer synthesis22–27 and post‐polymerization modification 28–31. However, microwave‐irradiation has had somewhat limited application in CRP, and the results often appear inconsistent as a result of widely varying reaction setups.…”