Non-viral delivery of CRISPR–Cas9 complexes for targeted gene editing via a polymer delivery system

Recent advances in molecular biology have led to the CRISPR revolution, but the lack of an efficient and safe delivery system into cells and tissues continues to hinder clinical translation of CRISPR approaches. Polymeric vectors offer an attractive alternative to viruses as delivery vectors due to their large packaging capacity and safety profile. In this paper, we have demonstrated the potential use of a highly branched poly(β-amino ester) polymer, HPAE-EB, to enable genomic editing via CRISPRCas9-targeted genomic excision of exon 80 in the COL7A1 gene, through a dual-guide RNA sequence system. The biophysical properties of HPAE-EB were screened in a human embryonic 293 cell line (HEK293), to elucidate optimal conditions for efficient and cytocompatible delivery of a DNA construct encoding Cas9 along with two RNA guides, obtaining 15–20% target genomic excision. When translated to human recessive dystrophic epidermolysis bullosa (RDEB) keratinocytes, transfection efficiency and targeted genomic excision dropped. However, upon delivery of CRISPR–Cas9 as a ribonucleoprotein complex, targeted genomic deletion of exon 80 was increased to over 40%. Our study provides renewed perspective for the further development of polymer delivery systems for application in the gene editing field in general, and specifically for the treatment of RDEB.

Co-Delivery of Paclitaxel and siRNA with pH-Responsive Polymeric Micelles for Synergistic Cancer Therapy

Due to the complex physiological characteristics of tumors, chemotherapy or gene therapy alone cannot completely kill tumor cells. Therefore, combining chemotherapy with gene therapy for combination therapy is the key to solving this problem. However, there are still significant challenges in how to simultaneously deliver and rapidly release the drugs and siRNA into cancer cells. In this work, a triblock copolymer was synthesized to co-deliver siRNA and paclitaxel to tumor cells. This system has an acid-sensitive subsurface layer, which can not only load siRNA to prevent premature drug release but also has good controlled release performance. In vitro experiments showed that polymeric vectors can efficiently deliver siRNA and paclitaxel simultaneously into tumor cells for rapid release within the tumor cells. This study reveals that this novel polymeric micelle is a suitable vector for the codelivery of chemotherapeutic drugs and siRNA to cancer cells, representing an important advance in nanotechnology, nanomedicine, drug delivery, and cancer therapy.

Aminoglycosides: From Antibiotics to Building Blocks for the Synthesis and Development of Gene Delivery Vehicles

Aminoglycosides are a class of naturally occurring and semi synthetic antibiotics that have been used for a long time in fighting bacterial infections. Due to acquired antibiotic resistance and inherent toxicity, aminoglycosides have experienced a decrease in interest over time. However, in the last decade, we are seeing a renaissance of aminoglycosides thanks to a better understanding of their chemistry and mode of action, which had led to new trends of application. The purpose of this comprehensive review is to highlight one of these new fields of application: the use of aminoglycosides as building blocks for the development of liposomal and polymeric vectors for gene delivery. The design, synthetic strategies, ability to condensate the genetic material, the efficiency in transfection, and cytotoxicity as well as when available, the antibacterial activity of aminoglycoside-based cationic lipids and polymers are covered and critically analyzed.

Vectors for Glioblastoma Gene Therapy: Viral & Non-Viral Delivery Strategies

Glioblastoma multiforme is the most common and aggressive primary brain tumor. Even with aggressive treatment including surgical resection, radiation, and chemotherapy, patient outcomes remain poor, with five-year survival rates at only 10%. Barriers to treatment include inefficient drug delivery across the blood brain barrier and development of drug resistance. Because gliomas occur due to sequential acquisition of genetic alterations, gene therapy represents a promising alternative to overcome limitations of conventional therapy. Gene or nucleic acid carriers must be used to deliver these therapies successfully into tumor tissue and have been extensively studied. Viral vectors have been evaluated in clinical trials for glioblastoma gene therapy but have not achieved FDA approval due to issues with viral delivery, inefficient tumor penetration, and limited efficacy. Non-viral vectors have been explored for delivery of glioma gene therapy and have shown promise as gene vectors for glioma treatment in preclinical studies and a few non-polymeric vectors have entered clinical trials. In this review, delivery systems including viral, non-polymeric, and polymeric vectors that have been used in glioblastoma multiforme (GBM) gene therapy are discussed. Additionally, advances in glioblastoma gene therapy using viral and non-polymeric vectors in clinical trials and emerging polymeric vectors for glioma gene therapy are discussed.

A combinatorial library of triazine-cored polymeric vectors for pDNA delivery in vitro and in vivo

Triazine-cored cationic amphiphilic polymers as potentially safe and effective carriers demonstrated in vitro and in vivo in mdx mice for pDNA delivery.