DNA Nanoflower Eye Drops with Antibiotic-Resistant Gene Regulation Ability for MRSA Keratitis Target Treatment.

Methicillin-resistant Staphylococcus aureus (MRSA) biofilm-associated bacterial keratitis is highly intractable, with strong resistance to ß-lactam antibiotics. Inhibiting the MRSA resistance gene mecR1 to downregulate penicillin-binding protein PBP2a has been implicated in the sensitization of ß-lactam antibiotics to MRSA. However, oligonucleotide gene regulators struggle to penetrate dense biofilms, let alone achieve efficient gene regulation inside bacteria cells. Herein, an eye-drop system capable of penetrating biofilms and targeting bacteria for chemo-gene therapy in MRSA-caused bacterial keratitis is developed. This system employed rolling circle amplification to prepare DNA nanoflowers (DNFs) encoding MRSA-specific aptamers and mecR1 deoxyribozymes (DNAzymes). Subsequently, ß-lactam antibiotic ampicillin (Amp) and zinc oxide (ZnO) nanoparticles are sequentially loaded into the DNFs (ZnO/Amp@DNFs). Upon application, ZnO on the surface of the nanosystem disrupts the dense structure of biofilm and fully exposes free bacteria. Later, bearing encoded aptamer, the nanoflower system is intensively endocytosed by bacteria, and releases DNAzyme under acidic conditions to cleave the mecR1 gene for PBP2a down-regulation, and ampicillin for efficient MRSA elimination. In vivo tests showed that the system effectively cleared bacterial and biofilm in the cornea, suppressed proinflammatory cytokines interleukin 1ß ï¼ˆIL-1ß） and tumor neocrosis factor-alpha （TNF-α）, and is safe for corneal epithelial cells. Overall, this design offers a promising approach for treating MRSA-induced keratitis.

Peritumoral Microgel Reservoir for Long-Term Light-Controlled Triple-Synergistic Treatment of Osteosarcoma with Single Ultra-Low Dose.

Local minimally invasive injection of anticancer therapies is a compelling approach to maximize the utilization of drugs and reduce the systemic adverse drug effects. However, the clinical translation is still hampered by many challenges such as short residence time of therapeutic agents and the difficulty in achieving multi-modulation combination therapy. Herein, mesoporous silica-coated gold nanorods (AuNR@SiO2 ) core-shell nanoparticles are fabricated to facilitate drug loading while rendering them photothermally responsive. Subsequently, AuNR@SiO2 is anchored into a monodisperse photocrosslinkable gelatin (GelMA) microgel through one-step microfluidic technology. Chemotherapeutic drug doxorubicin (DOX) is loaded into AuNR@SiO2 and 5,6-dimethylxanthenone-4-acetic acid (DMXAA) is loaded in the microgel layer. The osteosarcoma targeting ligand alendronate is conjugated to AuNR@SiO2 to improve the tumor targeting. The microgel greatly improves the injectability since they can be dispersed in buffer and the injectability and degradability are adjustable by microfluidics during the fabrication. The drug release can, in turn, be modulated by multi-round light-trigger. Importantly, a single super low drug dose (1 mg kg-1 DOX with 5 mg kg-1 DMXAA) with peritumoral injection generates long-term therapeutic effect and significantly inhibited tumor growth in osteosarcoma bearing mice. Therefore, this nanocomposite@microgel system can act as a peritumoral reservoir for long-term effective osteosarcoma treatment.

A Novel Eyes Topical Drug Delivery System: CsA-LNC for the Treatment of DED.

PURPOSE: The objective of the present work was to prepare safe and effective Ciclosporin A Lipid nanocapsule (CsA-LNC) eye-drops for the treatment of DED. METHODS: The phase-inversion method was used to prepared different sizes CsA-LNC. CsA biodistribution in ocular after topical administration in rabbits was analyzed by a validated UPLC-MS/MS method. The efficacy of CsA-LNCs (25 nm, 50 nm, 85 nm) was evaluated using the tear breakup time, fluorescein staining, tear production, inflammatory cytokines and histopathology tests. The safety of CsA-LNCs was study by the score of ocular irritation and histological examination study. RESULTS: CsA-LNCs(20-100 nm) were successfully prepared, An in vivo PK study showed significant improvement of the bioavailability (4.20-fold (25 nm), 2.15-fold (50 nm) and 2.33-fold (85 nm)) in bulbar conjunctiva, and great permeability was observed in the cornea for CsA-LNCs compared with CsA emulsion. An in vivo PD study showed that CsA-LNCs have great efficacy for DED, and the effect was improved over CsA emulsion. CsA-LNCs were safe and not cause significant irritation to the eyes surface of rabbits. CONCLUSION: This work has demonstrated CsA-LNCs, in particular small sizes CsA-LNC, are safe and effective with promising potential to treat DED. Grapical abstract.

Development of Aptamer-DNAzyme based metal-nucleic acid frameworks for gastric cancer therapy.

The metal-nucleic acid nanocomposites, first termed metal-nucleic acid frameworks (MNFs) in this work, show extraordinary potential as functional nanomaterials. However, thus far, realized MNFs face limitations including harsh synthesis conditions, instability, and non-targeting. Herein, we discover that longer oligonucleotides can enhance the synthesis efficiency and stability of MNFs by increasing oligonucleotide folding and entanglement probabilities during the reaction. Besides, longer oligonucleotides provide upgraded metal ions binding conditions, facilitating MNFs to load macromolecular protein drugs at room temperature. Furthermore, longer oligonucleotides facilitate functional expansion of nucleotide sequences, enabling disease-targeted MNFs. As a proof-of-concept, we build an interferon regulatory factor-1(IRF-1) loaded Ca2+/(aptamer-deoxyribozyme) MNF to target regulate glucose transporter (GLUT-1) expression in human epidermal growth factor receptor-2 (HER-2) positive gastric cancer cells. This MNF nanodevice disrupts GSH/ROS homeostasis, suppresses DNA repair, and augments ROS-mediated DNA damage therapy, with tumor inhibition rate up to 90%. Our work signifies a significant advancement towards an era of universal MNF application.

Therapeutic DNAzymes: From Structure Design to Clinical Applications.

Therapeutic DNAzymes have unceasingly intrigued the scientific community owing to their prosperous gene regulation capability. The efficacy of DNAzymes against many types of diseases has been extensively studied for over two decades. However, the high expectations for DNAzymes are still not translated to the clinic because of their low effectiveness in vivo. Over the last five years, several aspects have been considered to optimize DNAzyme-integrated therapeutics, including structural stability, mechanism exploration, cell internalization rate, cofactor activation, and off-target effects. Hence, this review first discusses the early monotherapy and structural design of DNAzymes. Subsequently, the latest modes of action are reviewed, followed by an elaboration on structural stabilization strategies considering the catalytic core and substrate-binding arms. DNAzyme-based synergistic therapy is then examined, highlighting responsive carrier construction, synergistic effects, the latest discovered advanced functions, and off-target concerns. Beyond this, key clinical advances in DNAzyme-based therapy are elucidated by showcasing clinical progress. Finally, future trends and development challenges for DNAzyme-powered therapeutics in the coming years are discussed in detail.

An autocatalytic multicomponent DNAzyme nanomachine for tumor-specific photothermal therapy sensitization in pancreatic cancer.

Multicomponent deoxyribozymes (MNAzymes) have great potential in gene therapy, but their ability to recognize disease tissue and further achieve synergistic gene regulation has rarely been studied. Herein, Arginylglycylaspartic acid (RGD)-modified Distearyl acylphosphatidyl ethanolamine (DSPE)-polyethylene glycol (PEG) (DSPE-PEG-RGD) micelle is prepared with a DSPE hydrophobic core to load the photothermal therapy (PTT) dye IR780 and the calcium efflux pump inhibitor curcumin. Then, the MNAzyme is distributed into the hydrophilic PEG layer and sealed with calcium phosphate through biomineralization. Moreover, RGD is attached to the outer tail of PEG for tumor targeting. The constructed nanomachine can release MNAzyme and the cofactor Ca2+ under acidic conditions and self-assemble into an active mode to cleave heat shock protein (HSP) mRNA by consuming the oncogene miRNA-21. Silencing miRNA-21 enhances the expression of the tumor suppressor gene PTEN, leading to PTT sensitization. Meanwhile, curcumin maintains high intracellular Ca2+ to further suppress HSP-chaperone ATP by disrupting mitochondrial Ca2+ homeostasis. Therefore, pancreatic cancer is triple-sensitized to IR780-mediated PTT. The in vitro and in vivo results show that the MNAzyme-based nanomachine can strongly regulate HSP and PTEN expression and lead to significant pancreatic tumor inhibition under laser irradiation.

Fabricating nanoparticles co-loaded with survivin siRNA and Pt(IV) prodrug for the treatment of platinum-resistant lung cancer.

Resistance to platinum agents is a crucial challenge in the treatment of cancer using platinum drugs. To overcome the resistance of cells, the survivin protein is supposed to be decreased, since it has previously been found to be overexpressed in drug-resistant cancer cells in anti-apoptosis pathways, while the intracellular effective platinum accumulation should be increased. In the present work, a protamine/hyaluronic acid nanocarrier was used to load survivin siRNA with Pt(IV) loaded outside the coated polyglutamic acid (PGA) by chemical conjugation. The siRNA was released from the co-loaded nanoparticle prior to Pt(IV), in this way, the expression of survivin protein was effectively reduced, which, in turn, could avoid the anti-apoptosis of drug resistant cells. Here, Pt(IV) displayed a sustained release effect and gradually reduced to the toxic Pt(II) species, which reduced drug efflux and enhance apoptosis of the cancer cells. In vitro studies demonstrated that co-loaded nanoparticles resulted in similar cell killing performance in A549/DDP cells (cisplatin resistant) compared with non-siRNA loaded nanoparticles in A549 cells (cisplatin sensitive). NP-siRNA/Pt(IV) exhibited a greatly improved therapeutic effect (TIR, 82.46%) in a nude mice A549/DDP tumor model, with no serious adverse effects observed. Thus, co-loading of Pt(IV) and survivin siRNA nanoparticles could reverse cisplatin resistance and therefore has promising prospects for efficient cancer chemotherapy.

Local drug delivery systems as therapeutic strategies against periodontitis: A systematic review.

Periodontitis is a chronic inflammation of the soft tissue surrounding and supporting the teeth, which causes periodontal structural damage, alveolar bone resorption, and even tooth loss. Its prevalence is very high, with nearly 60% of the global population affected. Hence, periodontitis is an important public health concern, and the development of effective healing treatments for oral diseases is a major target of the health sciences. Currently, the application of local drug delivery systems (LDDS) as an adjunctive therapy to scaling and root planning (SRP) in periodontitis is a promising strategy, giving higher efficacy and fewer side effects by controlling drug release. The cornerstone of successful periodontitis therapy is to select an appropriate bioactive agent and route of administration. In this context, this review highlights applications of LDDS with different properties in the treatment of periodontitis with or without systemic diseases, in order to reveal existing challenges and future research directions.