Optimization of Mixed Micelles Based on Oppositely Charged Block Copolymers by Machine Learning for Application in Gene Delivery

Abstract

The COVID‐19 mRNA vaccines represent a milestone in developing non‐viral gene carriers, and their success highlights the crucial need for continued research in this field to address further challenges. Polymer‐based delivery systems are particularly promising due to their versatile chemical structure and convenient adaptability, but struggle with the toxicity‐efficiency dilemma. Introducing anionic, hydrophilic, or “stealth” functionalities represents a promising approach to overcome this dilemma in gene delivery. Here, two sets of diblock terpolymers are created comprising hydrophobic poly(n‐butyl acrylate) (PnBA), a copolymer segment made of hydrophilic 4‐acryloylmorpholine (NAM), and either the cationic 3‐guanidinopropyl acrylamide (GPAm) or the 2‐carboxyethyl acrylamide (CEAm), which is negatively charged at neutral conditions. These oppositely charged sets of diblocks are co‐assembled in different ratios to form mixed micelles. Since this experimental design enables countless mixing possibilities, a machine learning approach is applied to identify an optimal GPAm/CEAm ratio for achieving high transfection efficiency and cell viability with little resource expenses. After two runs, an optimal ratio to overcome the toxicity‐efficiency dilemma is identified. The results highlight the remarkable potential of integrating machine learning into polymer chemistry to effectively tackle the enormous number of conceivable combinations for identifying novel and powerful gene transporters.

Recent developments of polymeric delivery systems in gene therapeutics

“…It is the best tool for hyperparametric tuning in machine-learning experiments. 128 In order to investigate whether oppositely charged hybrid micelles maintain high transfection efficiency while having excellent cytocompatibility, Leer et al synthesized two sets of oppositely charged double-block terpolymers. 128 The two sets of copolymers contain the same hydrophobic poly( n -butyl acrylate) (PnBA) and hydrophilic 4-acryloylmethane (NAM).…”

“…128 In order to investigate whether oppositely charged hybrid micelles maintain high transfection efficiency while having excellent cytocompatibility, Leer et al synthesized two sets of oppositely charged double-block terpolymers. 128 The two sets of copolymers contain the same hydrophobic poly( n -butyl acrylate) (PnBA) and hydrophilic 4-acryloylmethane (NAM). The charge difference lies in the fact that the cationic copolymer is modified with 3-guanidinoacrylamide (GPAm), and the anionic copolymer is modified with 2-carboxyethylacrylamide (CEAm), which is negatively charged under neutral conditions.…”

Optimizing Biocompatibility and Gene Delivery with DMAEA and DMAEAm: A Niacin-Derived Copolymer Approach

“…The assays are based on measuring the increased or decreased fluorescence intensity of EtBr when intercalating with the genetic material or release of genetic material, respectively. 41 To study the ability of the polymer to complex genetic material, an EBA was performed. Therefore, the pKMyc was diluted as described in the polyplexation section with addition of EtBr (1 μg mL −1 ).…”

Tailoring Gene Transfer Efficacy through the Arrangement of Cationic and Anionic Blocks in Triblock Copolymer Micelles

“…The two sets each consisted of three triblock copolymers with a comparable degree of polymerization (DP) of the hydrophobic block ( H , DP ≈ 80) and either (i) an anionic middle block followed by a cationic outer block or (ii) a cationic middle block followed by an anionic outer block (Table ). Preliminary experiments with block copolymers showed that a molar amount of GPAm greater than 30 mol % and low amounts of CEAm are needed to achieve high transfection efficiencies, using NAM as a “stealth” moiety and for increased colloidal stability . Therefore, the amount of cationic GPAm ( C ) was varied between 30 and 37 mol %, while the amount of anionic CEAm ( A ) ranged from 6 to 14 mol %, which is shown in the bar chart of Figure B.…”

“…Preliminary experiments with block copolymers showed that a molar amount of GPAm greater than 30 mol % and low amounts of CEAm are needed to achieve high transfection efficiencies, using NAM as a “stealth” moiety and for increased colloidal stability. 41 Therefore, the amount of cationic GPAm ( C ) was varied between 30 and 37 mol %, while the amount of anionic CEAm ( A ) ranged from 6 to 14 mol %, which is shown in the bar chart of Figure 1 B. Numbers after hyphen ( HAC -g/c and HCA -g/c) represent the mol % of GPAm (g) and the mol % of CEAm (c).…”