Exploring the solid state properties of enzymatic poly(amine-co-ester) terpolymers to expand their applications in gene transfection

Abstract

Polymers bearing amino functional groups are an important class of materials capable of serving as non-viral carriers for DNA delivery to living cells. In this work biodegradable poly(amine-co-ester) terpolymers were synthesized via ring-opening and polycondensation copolymerization of lactone (ε-caprolactone (CL), ω-dodecalactone, ω-pentadecalactone (PDL), and ω-hexadecalactone) with diethyl sebacate (DES) and N-methyldiethanolamine (MDEA) in diphenyl ether, catalyzed by Candida antarctica lipase B (CALB). All lactone-DES-MDEA terpolymers had random distributions of lactone, sebacate, MDEA repeat units in the polymer chains. PDL-DES-MDEA terpolymers were studied in the composition range from 21 mol% to 90 mol% PDL whereas the terpolymers with other lactones were investigated at a single composition (80 mol% lactone). DSC and WAXS analyses showed that all investigated terpolymers crystallize in their respective homopolylactone crystal lattice. Terpolymers with large lactones and a high lactone content melt well above room temperature and are hard solids, whereas terpolymers with small lactones (e.g. CL) or with a low lactone content melt below/around ambient temperature and are waxy/gluey materials. Given the importance of hydrophobicity in influencing gene delivery, water contact angle measurements were carried out on lactone-DES-MDEA terpolymers showing that it is possible to tune the hydrophilic-to-hydrophobic balance by varying polymer composition and size of lactone units. To demonstrate the feasibility of using solid terpolymers as nanocarriers for DNA delivery, PDL-DES-MDEA copolymers with 65–90% PDL were successfully transformed into free-standing nanoparticles with average particle size ranging from 163 to 175 nm. Our preliminary results showed that LucDNA-loaded nanoparticles of the terpolymer with 65% PDL were effective for luciferase gene transfection of HEK293 cells.

Tunability of Biodegradable Poly(amine-co-ester) Polymers for Customized Nucleic Acid Delivery and Other Biomedical Applications

“…It is also notable that the PDI values in these syntheses are equivalent or slightly lower than those reported in prior publications. 5, 25–27 One key difference in this work is that we measured reactant ratios using molar ratios instead of weight percentages: it is possible that more control over the polymer synthesis output was achieved by this approach. There may also be significant differences in polymer molecular weights achieved due to the longer reaction times used in this method compared to prior methods.…”

Increased Nanoparticle Delivery to Brain Tumors by Autocatalytic Priming for Improved Treatment and Imaging

“…We recently developed enzyme-catalyzed chemistry for polymerization of diethyl sebacate (DES) and N -methyldiethanolamine (MDEA) with lactones . The chemistry allows fine-tuning of four features in a single polymer molecule: density of positive charge, molecular weight, hydrophobicity, and crystallinity. , In our previous report, we studied a group of liquid terpolymers synthesized through this chemistry and found that many of them were capable of forming liquid polyplex NPs for efficient gene delivery . However, due to the limited stability and drug-loading capacity, these liquid polyplex NPs are not suitable for systemic drug delivery to the brain (data not shown).…”

Polymers from macrolactones: From pheromones to functional materials

“…[211][212][213] The latter reaction was performed in the following two stages: 1) oligomerization under low vacuum to prevent monomer evaporation, followed by 2) polymerization under high vacuum to drive the equilibrium of transesterification to high conversion (Scheme 13). [211] Simultaneous eROP and condensation polymerization has also been reported in the preparation of 1) copolyesters from PDL and ethyl glycolate, [214] 2) poly(amine-co-ester)s [215,216] PMLs have been obtained via simultaneous eROP and condensation polymerization by performing the eROP of PDL in the presence of divinyl adipate and glycidol to yield α,ω-diepoxy functional PPDL. [226] Cationic photopolymerization of α,ω-diepoxy macromonomers and crosslinking using cycloaliphatic diepoxide formed durable crystalline films.…”

“…[206] Furthermore, α-chymotrypsin and DNase I loaded PEG-co-(glycerol adipate-co-PDL) microparticles prepared via spray drying from double emulsion were investigated as a potential dry powder inhalation treatment for local pulmonary diseases. [209] Additionally, poly(amine-co-ester) nanoparticles prepared from DDL, PDL, or HDL, diethyl sebacate, and N-methyldiethanolamine were investigated as non-viral carriers for gene transfection and copolymers containing PDL were determined to be effective for luciferase gene transfection of HEK293 cells in vitro [215] and targeted gene delivery to tumour cells in vivo. [216] Finally, PEGylated poly(amine-co-ester), [222,223] poly(lactone-co-β-amino ester), [225] and poly(amine-co-disulfide ester) [224] block copolymer micelles featuring PDL have been determined to be promising new pH and/or redox responsive vectors for drug and gene delivery applications.…”