Polyplex-Loaded Hydrogels for Local Gene Delivery to Human Dermal Fibroblasts

Gene Delivery From Granular Scaffolds for Tunable Biologics Manufacturing

The understanding of the molecular basis for disease has generated a myriad of therapeutic biologics, including therapeutic proteins, antibodies, and viruses. However, the promise that biologics can resolve currently incurable diseases hinges in their manufacturability. These therapeutics require that their genetic material be introduced to mammalian cells such that the cell machinery can manufacture the biological components. These are then purified, validated, and packaged. Most manufacturing uses batch processes that collect the biologic a few days following genetic modification, due to toxicity or difficulty in separating product from cells in a continuous operation, limiting the amount of biologic that can be produced and resulting in yearlong backlogs. Here, a scaffold-based approach for continuous biologic manufacturing is presented, with sustained production of active antibodies and viruses for 30 days. The use of scaffold-based biologic production enabled perfusion-based bioreactors to be used, which can be incorporated into a fully continuous process.

Transforming Cell-Drug Interaction through Granular Hydrogel-Mediated Delivery of Polyplex Nanoparticles for Enhanced Safety and Extended Efficacy in Gene Therapy

The utilization of hydrogels for DNA/cationic polymer polyplex nanoparticle (polyplex) delivery has significantly advanced gene therapy in tissue regeneration and cancer treatment. However, persistent challenges related to the efficacy and safety of encapsulated polyplexes, stemming from issues such as aggregation, degradation, or difficulties in controlled release during or postintegration with hydrogel scaffolds, necessitate further exploration. Here, we introduce an injectable gene therapy gel achieved by incorporating concentrated polyplexes onto densely packed hydrogel microparticles (HMPs). Polyplexes, when uniformly adhered to the gene therapy gel through reversible electrostatic interactions, can detach from the HMP surface in a controlled manner, contrasting with free polyplexes, and thereby reducing dose-dependent toxicity during transfection. Additionally, the integration of RGD cell adhesion peptides enhances the scaffolding characteristics of the gel, facilitating cell adhesion, migration, and further minimizing toxicity during gene drug administration. Notably, despite the overall transfection efficiency showing average performance, utilizing confocal microscopy to meticulously observe and analyze the cellular states infiltrating into various depths of the gene therapy gel resulted in the groundbreaking discovery of significantly enhanced local transfection efficiency, with primary cell transfection approaching 80%. This phenomenon could be potentially attributed to the granular hydrogel-mediated delivery of polyplex nanoparticles, which revolutionizes the spatial and temporal distribution and thus the "encounter" mode between polyplexes and cells. Moreover, the gene therapy gel's intrinsic injectability and self-healing properties offer ease of administration, making it a highly promising candidate as a novel gene transfection gel dressing with significant potential across various fields, including regenerative medicine and innovative living materials.

Growth factors and growth factor gene therapies for treating chronic wounds

Chronic wounds are an unmet clinical need affecting millions of patients globally, and current standards of care fail to consistently promote complete wound closure and prevent recurrence. Disruptions in growth factor signaling, a hallmark of chronic wounds, have led researchers to pursue growth factor therapies as potential supplements to standards of care. Initial studies delivering growth factors in protein form showed promise, with a few formulations reaching clinical trials and one obtaining clinical approval. However, protein-form growth factors are limited by instability and off-target effects. Gene therapy offers an alternative approach to deliver growth factors to the chronic wound environment, but safety concerns surrounding gene therapy as well as efficacy challenges in the gene delivery process have prevented clinical translation. Current growth factor delivery and gene therapy approaches have primarily used single growth factor formulations, but recent efforts have aimed to develop multi-growth factor approaches that are better suited to address growth factor insufficiencies in the chronic wound environment, and these strategies have demonstrated improved efficacy in preclinical studies. This review provides an overview of chronic wound healing, emphasizing the need and potential for growth factor therapies. It includes a summary of current standards of care, recent advances in growth factor, cell-based, and gene therapy approaches, and future perspectives for multi-growth factor therapeutics.

mRNA Delivery: Challenges and Advances through Polymeric Soft Nanoparticles

Single-stranded messenger ribonucleic acid (mRNA) plays a pivotal role in transferring genetic information, and tremendous effort has been devoted over the years to utilize its transcription efficacy in therapeutic interventions for a variety of diseases with high morbidity and mortality. Lipid nanocarriers have been extensively investigated for mRNA delivery and enabled the rapid and successful development of mRNA vaccines against SARS-CoV-2. Some constraints of lipid nanocarriers have encouraged the development of alternative delivery systems, such as polymer-based soft nanoparticles, which offer a modular gene delivery platform. Such macromolecule-based nanocarriers can be synthetically articulated for tailored parameters including mRNA protection, loading efficacy, and targeted release. In this review, we highlight recent advances in the development of polymeric architectures for mRNA delivery, their limitations, and the challenges that still exist, with the aim of expediting further research and the clinical translation of such formulations.

A machine learning approach to predict cellular uptake of pBAE polyplexes

The delivery of genetic material (DNA and RNA) to cells can cure a wide range of diseases but is limited by the delivery efficiency of the carrier system. Poly β-amino esters (pBAEs) are promising polymer-based vectors that form polyplexes with negatively charged oligonucleotides, enabling cell membrane uptake and gene delivery. pBAE backbone polymer chemistry, as well as terminal oligopeptide modifications, define cellular uptake and transfection efficiency in a given cell line, along with nanoparticle size and polydispersity. Moreover, uptake and transfection efficiency of a given polyplex formulation also vary from cell type to cell type. Therefore, finding the optimal formulation leading to high uptake in a new cell line is dictated by trial and error, and requires time and resources. Machine learning (ML) is an ideal in silico screening tool to learn the non-linearities of complex data sets, like the one presented herein, with the aim of predicting cellular internalisation of pBAE polyplexes. A library of pBAE nanoparticles was fabricated and the uptake studied in 4 different cell lines, on which various ML models were successfully trained. The best performing models were found to be gradient-boosted trees and neural networks. The gradient-boosted trees model was then analysed using SHapley Additive exPlanations, to interpret the model and gain an understanding into the important features and their impact on the predicted outcome.

DNA hydrogels and nanogels for diagnostics, therapeutics, and theragnostics of various cancers

As an efficient class of hydrogel-based therapeutic drug delivery systems, deoxyribonucleic acid (DNA) hydrogels (particularly DNA nanogels) have attracted massive attention in the last five years. The main contributor to this is the programmability of these 3-dimensional (3D) scaffolds that creates fundamental effects, especially in treating cancer diseases. Like other active biological ingredients (ABIs), DNA hydrogels can be functionalized with other active agents that play a role in targeting drug delivery and modifying the half-life of the therapeutic cargoes in the body's internal environment. Considering the brilliant advantages of DNA hydrogels, in this survey, we intend to submit an informative collection of feasible methods for the design and preparation of DNA hydrogels and nanogels, and the responsivity of the immune system to these therapeutic cargoes. Moreover, the interactions of DNA hydrogels with cancer biomarkers are discussed in this account. Theragnostic DNA nanogels as an advanced species for both detection and therapeutic purposes are also briefly reviewed.

Hydrogels for Mucosal Drug Delivery

Mucosal tissues are often a desirable site of drug action to treat disease and engage the immune system. However, systemically administered drugs suffer from limited bioavailability in mucosal tissues where technologies to enable direct, local delivery to these sites would prove useful. In this Spotlight on Applications article, we discuss hydrogels as an attractive means for local delivery of therapeutics to address a range of conditions affecting the eye, nose, oral cavity, gastrointestinal, urinary bladder, and vaginal tracts. Considering the barriers to effective mucosal delivery, we provide an overview of the key parameters in the use of hydrogels for these applications. Finally, we highlight recent work demonstrating their use for inflammatory and infectious diseases affecting these tissues.

Gelatin-Based Electrospun Nanofibers Cross-Linked Using Horseradish Peroxidase for Plasmid DNA Delivery

The delivery of nucleic acids is indispensable for tissue engineering and gene therapy. However, the current approaches involving DNA/RNA delivery by systemic and local injections face issues such as clearance, off-target distribution, and tissue damage. In this study, we report plasmid DNA (pDNA) delivery using gelatin electrospun nanofibers obtained through horseradish peroxidase (HRP)-mediated insolubilization. The nanofibers were obtained through the electrospinning of an aqueous solution containing gelatin possessing phenolic hydroxyl (Ph) moieties (Gelatin-Ph) and HRP with subsequent HRP-mediated cross-linking of the Ph moieties by exposure to air containing 16 ppm H2O2 for 30 min. Then, Lipofectamine/pDNA complexes were immobilized on the nanofibers through immersion in the solution containing the pDNA complexes, resulting in transfection and sustained delivery of pDNA. Cells cultured on the resultant nanofibers expressed genome-editing molecules including Cas9 protein and guide RNA (gRNA), resulting in targeted gene knock-in and knock-out. These results demonstrated the potential of Gelatin-Ph nanofibers obtained through electrospinning and subsequent HRP-mediated cross-linking for gene therapy and tissue regeneration by genome editing.

Polymer-based Non-viral Vectors for Gene Therapy in the Skin

Gene therapy has emerged as a versatile technique with the potential to treat a range of human diseases; however, examples of the topical application of gene therapy as a treatment...