Enhancing gene transfection of poly(β-amino ester)s through modulation of amphiphilicity and chain sequence

Poly(β-amino ester)s (PAEs) have emerged as a type of highly safe and efficient non-viral DNA delivery vectors. However, the influence of amphiphilicity and chain sequence on DNA transfection efficiency and safety profile remain largely unexplored. In this study, four PAEs with distinct amphiphilicity and chain sequences were synthesized. Results show that both amphiphilicity and chain sequence significantly affect the DNA binding and condensation ability of PAEs, as well as size, zeta potential and cellular uptake of PAE/DNA polyplexes. PAEs with different amphiphilicity and chain sequence exhibit cell type-dependent transfection capabilities: in human bladder transitional cell carcinoma (UM-UC-3), hydrophilic PAE (P-Philic) and amphiphilic PAE random copolymer (R-Amphilic) exhibit relatively higher gene transfection efficiency, while in human bladder epithelial immortalized cells (SV-HUC-1), hydrophobic PAE (P-Phobic), R-Amphilic, and amphiphilic PAE block copolymer (B-Amphilic) demonstrate higher transfection capability. Regardless of cell types, amphiphilic PAE block copolymer (B-Amphilic) always exhibits much lower gene transfection efficiency. In addition, in human colon cancer cells (HCT-116), P-Philic and R-Amphilic achieved superior gene transfection efficiency at high and low polymer/DNA weight ratios, respectively. Importantly, R-Amphilic can effectively deliver the gene encoding tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) to human chondrosarcoma cells SW1353 to induce their apoptosis, highlighting its potential application in cancer gene therapy. This study not only establishes a new paradigm for enhancing the gene transfection efficiency of PAEs by modulating their amphiphilicity and chain sequence but also identifies R-Amphilic as a potential candidate for the effective delivery of TRAIL gene in cancer gene therapy.

Fluorinated vectors for gene delivery

INTRODUCTION

Gene delivery vectors are a crucial determinant for gene therapeutic efficacy. Usually, it is necessary to use an excess of cationic vectors to achieve better transfection efficiency. However, it will cause severe cytotoxicity. In addition, cationic vectors are not resistant to serum, suffering from reduced transfection efficiency by forming large aggregates. Therefore, there is an urgent need to develop optimized gene delivery vectors. Recently, fluorination of vectors has been extensively applied to increase the gene delivery performance because of the unique properties of both hydrophobicity and lipophobicity, and chemical and biological inertness.

AREAS COVERED

This review will discuss the fluorophilic effects that impact gene delivery efficiency, and chemical modification approaches for fluorination. Next, recent advances and applications of fluorinated polymeric and lipidic vectors in gene therapy and gene editing are summarized.

EXPERT OPINION

Fluorinated vectors are a promising candidate for gene delivery. However, it still needs further studies to obtain pure and well-defined fluorinated polymers, guarantee the biosafety, and clarify the detailed mechanism. Apart from the improvements in gene delivery, exploiting other versatility of fluorinated vectors, such as oxygen-carrying ability, high affinity with fluorine-containing drugs, and imaging property upon introducing 19^F, will further facilitate their applications in gene therapy.

Adeno-associated virus (AAV) vectors in cancer gene therapy

Gene delivery vectors based on adeno-associated virus (AAV) have been utilized in a large number of gene therapy clinical trials, which have demonstrated their strong safety profile and increasingly their therapeutic efficacy for treating monogenic diseases. For cancer applications, AAV vectors have been harnessed for delivery of an extensive repertoire of transgenes to preclinical models and, more recently, clinical trials involving certain cancers. This review describes the applications of AAV vectors to cancer models and presents developments in vector engineering and payload design aimed at tailoring AAV vectors for transduction and treatment of cancer cells. We also discuss the current status of AAV clinical development in oncology and future directions for AAV in this field.