Nanomedicine Approaches to Negotiate Local Biobarriers for Topical Drug Delivery

AbstractTopical treatments have been widely adopted to address a broad range of conditions across multiple sites thanks to their convenience, versatility, and effectiveness. While bypassing systemic biobarriers and avoiding systemic side effects by delivering directly to the target tissue, topical treatments still face significant local biobarriers that limit their efficacy. The toolset available for nanodelivery systems and their inherent multifunctionality can contribute to simultaneously address otherwise intractable challenges related to barrier function evasion, drug solubility, bioavailability, pharmacokinetics, smart and sustained release, quantitative co‐delivery, and local targeting which are key to successful topical treatments. This review summarizes the outstanding challenges associated with the topical treatments of key diseases of the skin, mucosae, eyes, and ears, and highlights how nanodelivery systems are being developed to address them effectively

Nanomedicine Approaches to Negotiate Local Biobarriers for Topical Drug Delivery

Topical treatments have been widely adopted to address a broad range of conditions across multiple sites thanks to their convenience, versatility, and effectiveness. While bypassing systemic biobarriers and avoiding systemic side effects by delivering directly to the target tissue, topical treatments still face significant local biobarriers that limit their efficacy. The toolset available for nanodelivery systems and their inherent multifunctionality can contribute to simultaneously address otherwise intractable challenges related to barrier function evasion, drug solubility, bioavailability, pharmacokinetics, smart and sustained release, quantitative co-delivery, and local targeting which are key to successful topical treatments. This review summarizes the outstanding challenges associated with the topical treatments of key diseases of the skin, mucosae, eyes, and ears, and highlights how nanodelivery systems are being developed to address them effectively

CRISPR/Cas-assisted Nanoneedle Sensor for ATP Detection in Living Cells

The clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas) (CRISPR/Cas) systems have recently emerged as a powerful molecular biosensing tool based on their collateral cleavage activity due to their simplicity, sensitivity, specificity, and broad applicability. However, the direct application of collateral cleavage activity for in-situ intracellular detection is still challenging. Here, we debut a CRISPR/Cas-assisted nanoneedle sensor (nanoCRISPR) for intracellular adenosine triphosphate (ATP), which avoids the challenges associated with intracellular collateral cleavage by introducing a two-step process of intracellular target recognition followed by extracellular transduction and detection. ATP recognition occurs by first presenting in the cell cytosol an aptamer-locked Cas12a activator conjugated to nanoneedles; the recognition event unlocks the activator immobilized on the nanoneedles. The nanoneedles are then removed from the cells and exposed to the Cas12a/crRNA complex, where the activator triggers the cleavage of a ssDNA fluorophore-quencher pair, generating a detectable fluorescence signal. NanoCRISPR has an ATP detection limit of 246 nM and a dynamic range from 1.56 μM to 50 μM. Importantly, nanoCRISPR can detect intracellular ATP in 30 min in live cells without impacting cell viability. We anticipate that the nanoCRISPR approach will contribute to broaden the biomedical applications of CRISPR/Cas sensors for the detection of diverse intracellular molecules in living systems

Salmonella Engages Host MicroRNAs To Modulate SUMOylation: a New Arsenal for Intracellular Survival

Posttranslational modifications (PTMs) can alter many fundamental properties of a protein. One or combinations of them have been known to regulate the dynamics of many cellular pathways and consequently regulate all vital processes. Understandably, pathogens have evolved sophisticated strategies to subvert these mechanisms to achieve instantaneous control over host functions. Here, we present the first report of modulation by intestinal pathogen Salmonella enterica serovar Typhimurium (S. Typhimurium) of host SUMOylation, a PTM pathway central to all fundamental cellular processes. Both in cell culture and in a mouse model, we observed that S. Typhimurium infection led to a dynamic SUMO-conjugated proteome alteration. The intracellular survival of S. Typhimurium was dependent on SUMO status as revealed by reduced infection and Salmonella-induced filaments (SIFs) in SUMO-upregulated cells. S. Typhimurium-dependent SUMO modulation was seen as a result of depletion of crucial SUMO pathway enzymes Ubc-9 and PIAS1, at both the protein and the transcript levels. Mechanistically, depletion of Ubc-9 relied on upregulation of small noncoding RNAs miR30c and miR30e during S. Typhimurium infection. This was necessary and sufficient for both down-modulation of Ubc-9 and a successful infection. Thus, we demonstrate a novel strategy of pathogen-mediated perturbation of host SUMOylation, an integral mechanism underlying S. Typhimurium infection and intracellular survival

Nanoneedles Induce Targeted siRNA Silencing of p16 in the Human Corneal Endothelium

: Nanoneedles can target nucleic acid transfection to primary cells at tissue interfaces with high efficiency and minimal perturbation. The corneal endothelium is an ideal target for nanoneedle-mediated RNA interference therapy aimed at enhancing its proliferative capacity, necessary for tissue regeneration. This work develops a strategy for siRNA nanoninjection to the human corneal endothelium. Nanoneedles can deliver p16-targeting siRNA to primary human corneal endothelial cells in vitro without toxicity. The nanoinjection of siRNA induces p16 silencing and increases cell proliferation, as monitored by ki67 expression. Furthermore, siRNA nanoinjection targeting the human corneal endothelium is nontoxic ex vivo, and silences p16 in transfected cells. These data indicate that nanoinjection can support targeted RNA interference therapy for the treatment of endothelial corneal dysfunction

SUMOylation pathway alteration coupled with downregulation of SUMO E2 enzyme at mucosal epithelium modulates inflammation in inflammatory bowel disease

Post-translational modification pathways such as SUMOylation are integral to all cellular processes and tissue homeostasis. We investigated the possible involvement of SUMOylation in the epithelial signalling in Crohn's disease (CD) and ulcerative colitis (UC), the two major forms of inflammatory bowel disease (IBD). Initially in a murine model of IBD, induced by dextran-sulfate-sodium (DSS mice), we observed inflammation accompanied by a lowering of global SUMOylation of colonic epithelium. The observed SUMOylation alteration was due to a decrease in the sole SUMO E2 enzyme (Ubc9). Mass-spectrometric analysis revealed the existence of a distinct SUMOylome (SUMO-conjugated proteome) in DSS mice with alteration of key cellular regulators, including master kinase Akt1. Knocking-down of Ubc9 in epithelial cells resulted in dramatic activation of inflammatory gene expression, a phenomenon that acted via reduction in Akt1 and its SUMOylated form. Importantly, a strong decrease in Ubc9 and Akt1 was also seen in endoscopic biopsy samples (N = 66) of human CD and UC patients. Furthermore, patients with maximum disease indices were always accompanied by severely lowered Ubc9 or SUMOylated-Akt1. Mucosal tissues with severely compromised Ubc9 function displayed higher levels of pro-inflammatory cytokines and compromised wound-healing markers. Thus, our results reveal an important and previously undescribed role for the SUMOylation pathway involving Ubc9 and Akt1 in modulation of epithelial inflammatory signalling in IBD.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Integrating Porous Silicon Nanoneedles within Medical Devices for Nucleic Acid Nanoinjection

Porous silicon nanoneedles can interface with cells and tissues with minimal perturbation for high-throughput intracellular delivery and biosensing. Typically, nanoneedle devices are rigid, flat, and opaque, which limits their use for topical applications in the clinic. We have developed a robust, rapid, and precise substrate transfer approach to incorporate nanoneedles within diverse substrates of arbitrary composition, flexibility, curvature, transparency, and biodegradability. With this approach, we integrated nanoneedles on medically relevant elastomers, hydrogels, plastics, medical bandages, catheter tubes, and contact lenses. The integration retains the mechanical properties and transfection efficiency of the nanoneedles. Transparent devices enable the live monitoring of cell–nanoneedle interactions. Flexible devices interface with tissues for efficient, uniform, and sustained topical delivery of nucleic acids ex vivo and in vivo. The versatility of this approach highlights the opportunity to integrate nanoneedles within existing medical devices to develop advanced platforms for topical delivery and biosensing.<p/

Supplementary material Salman et al from SUMOylation pathway alteration coupled with downregulation of SUMO-E2 enzyme at mucosal epithelium modulates inflammation in inflammatory bowel disease

SUMO-IBD supplementary figures and table