Gene Delivery Properties of End-Modified Poly(β-amino ester)s

Gene therapy has emerged as an alternative for the treatment of diseases refractory to conventional therapeutics. Synthetic nanoparticle-based gene delivery systems offer highly tunable platforms for the delivery of therapeutic genes. However, the inability to achieve sustained, high-level transgene expression in vivo presents a significant hurdle. The respiratory system, although readily accessible, remains a challenging target, as effective gene therapy mandates colloidal stability in physiological fluids and the ability to overcome biological barriers found in the lung. We formulated highly stable DNA nanoparticles based on state-of-theart biodegradable polymers, poly(β-amino esters) (PBAEs), possessing a dense corona of polyethylene glycol. We found that these nanoparticles efficiently penetrated the nanoporous and highly adhesive human mucus gel layer that constitutes a primary barrier to reaching the underlying epithelium. We also discovered that these PBAE-based mucus-penetrating DNA nanoparticles (PBAE-MPPs) provided uniform and high-level transgene expression throughout the mouse lungs, superior to several gold standard gene delivery systems. PBAE-MPPs achieved robust transgene expression over at least 4 mo following a single administration, and their transfection efficiency was not attenuated by repeated administrations, underscoring their clinical relevance. Importantly, PBAE-MPPs demonstrated a favorable safety profile with no signs of toxicity following intratracheal administration.lung gene therapy | mucus-penetrating particles | nanotechnology | biodegradable polymer | nonviral gene delivery

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“…S1) (7)(8)(9)(10)(11)(12)(13). PBAE polymers were synthesized by a two-step Michael addition, as previously reported (Fig.…”

Section: Methodsmentioning

confidence: 99%

Highly compacted biodegradable DNA nanoparticles capable of overcoming the mucus barrier for inhaled lung gene therapy

Mastorakos

Silva

Chisholm

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

171

151

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“…Interestingly, monomers 1 and 7 contain two amine groups, whereas monomers 9 and 11 contain two alcohol groups. Both functionalities have been previously associated with increased gene delivery (25,26,29).…”

Section: Significancementioning

confidence: 97%

“…To improve upon delivery specificity, mannose, an antagonist of CD206 (primarily expressed on APCs) (35,36), was grafted onto D9 (8,29,37,38). In addition to promoting APC delivery specificity, CD206 is a type 1 membrane immune receptor that mediates uptake of bacteria (39).…”

Section: Significancementioning

confidence: 99%

Hybrid biosynthetic gene therapy vector development and dual engineering capacity

Jones¹,

Ravikrishnan²,

Chen³

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

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Genetic vaccines offer a treatment opportunity based upon successful gene delivery to specific immune cell modulators. Driving the process is the vector chosen for gene cargo packaging and subsequent delivery to antigen-presenting cells (APCs) capable of triggering an immune cascade. As such, the delivery process must successfully navigate a series of requirements and obstacles associated with the chosen vector and target cell. In this work, we present the development and assessment of a hybrid gene delivery vector containing biological and biomaterial components. Each component was chosen to design and engineer gene delivery separately in a complimentary and fundamentally distinct fashion. A bacterial (Escherichia coli) inner core and a biomaterial [poly (beta-amino ester)]-coated outer surface allowed the simultaneous application of molecular biology and polymer chemistry to address barriers associated with APC gene delivery, which include cellular uptake and internalization, phagosomal escape, and intracellular cargo concentration. The approach combined and synergized normally disparate vector properties and tools, resulting in increased in vitro gene delivery beyond individual vector components or commercially available transfection agents. Furthermore, the hybrid device demonstrated a strong, efficient, and safe in vivo humoral immune response compared with traditional forms of antigen delivery. In summary, the flexibility, diversity, and potential of the hybrid design were developed and featured in this work as a platform for multivariate engineering at the vector and cellular scales for new applications in gene delivery immunotherapy.

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“…Lead polymer C32 was end-capped with an expanded library of 36 different amines by Zugates et al to show wider structure/function relationships ( Figure 9C). 36,37 Lead modified polymers C32-103 and C32-117 were found to bind DNA with higher affinity and form nanoparticles that were ~30% smaller than those formed with regular amino alcohol terminated C32. 35 We also found that these modified PBAE nanoparticles enable an up to 5-fold increase in cellular DNA uptake compared with regular C32.…”

mentioning

confidence: 99%

A Combinatorial Polymer Library Approach Yields Insight into Nonviral Gene Delivery

Green¹,

2008

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CONSPECTUSThe potential of gene therapy to benefit human health is tremendous because almost all human diseases have a genetic component, from untreatable monogenic disorders to cancer and heart disease. Unfortunately, a method for gene therapy that is both effective and safe has remained elusive. It has been said that "there are only three problems in gene therapy -delivery, delivery, and delivery." (quote from I. M. Verma in Jaroff, L. TIME, 1999; Jan 11).This Account describes an alternative strategy to viral gene delivery: the design of biodegradable polymers that are able to deliver DNA like a synthetic virus. Using high-throughput synthesis and screening techniques, we have created libraries of over 2000 structurally unique poly(β-amino esters) (PBAEs). PBAEs are formed by the conjugate addition of amines to diacrylates. These biomaterials are promising for nonviral gene delivery due to their ability to condense plasmid DNA into small and stable nanoparticles and their ability to promote cellular uptake and endosomal escape. Our laboratory has iteratively improved PBAE nanoparticles through polymer end modifications and nanoparticle coatings. Lead PBAEs have high gene delivery efficacy and low cytotoxicity both in vitro and in vivo.Certain polymer structural characteristics are important for effective gene delivery. The best PBAEs are linear polymers of ~10 kDa that contain hydroxyl side chains and primary amine end groups. These polymers bind DNA to form nanoparticles that are small (<200 nm) and stable and have near-neutral ζpotential in the presence of serum-containing media. Lead PBAEs also contain tertiary amines that can buffer the low pH environment of endosomes and facilitate escape of polymer/DNA particles into the cytoplasm.Diamine end-modified 1,4-butanediol diacrylate-co-5-amino-1-pentanol polymers (C32) bind DNA more tightly and form smaller nanoparticles than other PBAEs. These nanoparticles also have higher cellular uptake and the best gene expression of all gene delivery polymers in the library. These polymers are more effective for gene delivery than top commercially available nonviral vectors including jet-PEI and Lipofectamine 2000 and are comparable to adenovirus for in vitro gene delivery to human primary cells. In vivo, these PBAE/ DNA particles are promising as cancer therapeutics. This Account summarizes the results of our laboratory in using a combinatorial polymer library approach to elucidate polymer structure/function relationships and enable the development of polymeric gene delivery nanoparticles with viral-like efficacy. Nonviral gene delivery systems make use of physical methods or a synthetic chemical vector or both to deliver the gene of interest. Limitations with viral approaches, including small cargo capacity, resistance to repeated infection, difficulty in production and quality control, and low safety, can be potentially overcome with a nonviral approach. Originally, nonviral gene delivery was simply delivery of naked plasmid DNA. To improve transfection, physical str...

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Gene Delivery Properties of End-Modified Poly(β-amino ester)s

Cited by 80 publications

References 50 publications

Highly compacted biodegradable DNA nanoparticles capable of overcoming the mucus barrier for inhaled lung gene therapy

Highly compacted biodegradable DNA nanoparticles capable of overcoming the mucus barrier for inhaled lung gene therapy

Hybrid biosynthetic gene therapy vector development and dual engineering capacity

A Combinatorial Polymer Library Approach Yields Insight into Nonviral Gene Delivery

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