The antimicrobial resistance (AMR) crisis necessitates strategies to revitalize existing antibiotics against multidrug-resistant pathogens. While cationic antimicrobial polymers can disrupt bacterial membranes, their clinical translation is hindered by host toxicity. Here we report a hierarchical, stimuli-responsive nanomedicine designed on principles of safety, specificity, switchability, and synergy. We synthesized phenylboronic ester-caged biodegradable polymers shielded by functional polysaccharide shells. These nanoparticles remain inert during circulation but selectively activate within infection microenvironments. Upon activation, the exposed cationic polymer physically compromises bacterial membranes, enabling the entry of co-delivered antibiotics such as rifampicin into Gram-positive, Gram-negative, mycobacterial, and biofilm-embedded pathogens. Our research led to the discovery of glycans that significantly improve therapeutic outcomes. We found that different glycans exhibited distinct effects in various tissues and conditions: chondroitin sulfate effectively targeted CD44-abundant infectious niches, enabling precise localization and enhanced therapeutic efficacy, whereas levan uniquely stimulated macrophage oxidative bursts, promoting intracellular pathogen clearance. By leveraging these distinct biological interactions, our platform overcomes the physical and biological barriers of AMR, offering a universal strategy to treat diverse, multidrug-resistant infections.
R. Gao, Hongbing Liu, Wanbo Zhu et al.· Bioactive Materials· 0 citations
A novel genome-wide CRISPR screening strategy that will facilitate the systematic engineering of novel nonviral genome editing delivery methods, where the identified novel gene hits can be further used to increase editing efficiency for other therapeutically relevant cell types.
Shivani Saxena, Meha Kabra, Amr A. Abdeen et al.· bioRxiv· 2 citations
To systematically map cellular factors constraining nonviral genome editing, influencing uptake and intracellular trafficking, we develop a genome-wide CRISPR screening platform linking perturbation of 19,114 genes to editing outcomes in human cells. We identify six negative regulators of delivery whose depletion increases editing efficiency by up to six-fold across diverse payloads, loci, and cell types. We test the top two factors, GJB2 and BET1L, in two distinct human models: correction of a pathogenic adenine base mutation in KCNJ13 and introduction of a cytosine base mutation in the GABAA receptor gene. Depletion of either improves base-editing outcomes by 6-fold, potentially through effects on delivery. In a patient-derived model of retinal channelopathy, knockdown of either gene improves lipid nanoparticle base editing efficiency by over 3.5-fold. This enables functional restoration of Kir7.1 ion channels in a subset of edited cells, highlighting cellular barriers as actionable targets to enhance the potency of genetic therapies. Low editing efficiency of nonviral delivery in post mitotic tissues presents a challenge to the field of gene therapy. Here, authors dissect the genetic regulators of nonviral delivery in post mitotic retinal epithelial cells describe strategies for improved base editor delivery and editing.
Shivani Saxena, Meha Kabra, Amr A. Abdeen et al.· Nature Communications· 0 citations