Non-covalent nano-adducts of co-poly(ester amide) and poly(ethylene glycol): preparation, characterization and model drug-release studies

Abstract

Biodegradable, biocompatible poly(ester amide)s (co-PEAs), composed of amino acids, fatty diols and carboxylic acids, have been synthesized. To improve the performance of co-PEAs in Federal Drug Administration-approved solvents such as water and ethanol, these polymers were complexed with poly(ethylene glycol) (PEG) of 10 kDa molecular mass have been prepared by solution blending. The non-covalent adducts were purified by precipitation into hexanes. Co-PEAs are soluble in organic solvents but are insoluble in water and ethanol; however, the co-PEA/PEG (0.8:1, w/w) adducts are soluble in ethanol and slightly soluble in water. 2D-NOESY NMR spectroscopy suggests that the non-covalent adducts are held together by multiple non-covalent interactions between the -CH2- groups of the two polymers (co-PEA and PEG). Differential scanning calorimetry studies indicate that the two polymers are interacting in the non-covalent adducts; the thermal properties of the adducts are different from those of the pure polymers. The solid-state adduct structures have been determined by atomic force microscopy (AFM). By one sample preparation method, nanoscale pancake-like structures were observed with an average diameter of 260 nm and an average height of 16 nm. Films of co-PEAs and (co-PEA)/PEG adducts containing Rhodamine B Base (RhBB), a model hydrophobic drug, were prepared. From the adduct/RhBB film containing 3% RhBB, 20% of the total RhBB was released within the first 2 h. Film and adduct composition may be varied to obtain different release profiles. The studies reported here demonstrate that non-covalent conjugation is a relatively easy and effective approach in developing new materials for application as biomaterials.

Evaluation of Phenylbutazone and Poly(Amidoamine) Dendrimers Interactions by a Combination of Solubility, 2D-NOESY NMR, and Isothermal Titration Calorimetry Studies

“…2D‐NOESY measurements can provide information on the distance between protons in close spatial proximity within a given molecule and can also be used to detect the host–guest interactions in solutions 41–45. This technique was employed in this study to further investigate the interaction details between dendrimers and phenylbutazone molecules.…”

Biodegradable Polymers Composed of Naturally Occurring α‐Amino Acids

“…Legashvili et al [31] used brush -like co -PEAs ( Figure 5.11 ) to obtain molecular complexes with PEGs that are promising as nanocarriers of drugs.…”

Synthesis and Characterization of α,ω‐bi[2,4‐dinitrophenyl (DNP)] poly(2‐methoxystyrene) Functional Polymers. Initial Evaluation of the Interaction of the Functional Polymers with RBL Mast Cells

“…The CDNP-PEO-P2MS-PEO-CDNP also had limited solubility in water and the water solubility can be improved through complexation with dimethoxypoly(ethylene glycol), DMEG, of molecular weight 550 (16). The functional CDNP-PEO-P2MS-PEO-CDNP # 3 (13.9 K), Table 2 was incubated with DMEG-550 in the weight ratio of 1:20 to form a complex (CDNP-PEO-P2MS-PEO-CDNP:DMEG).…”