Biophilic Positive Carbon Dot Exerts Antifungal Activity and Augments Corneal Permeation for Fungal Keratitis.

Fungal keratitis (FK) is an infectious eye disease that poses a significant risk of blindness. However, the effectiveness of conventional antifungal drugs is limited due to the intrinsic ocular barrier that impedes drug absorption. There is an urgent need to develop new therapeutic strategies to effectively combat FK. Herein, we synthesized an ultrasmall positively charged carbon dot using a simple stage-melting method. The carbon dot can penetrate the corneal barrier by opening the tight junctions, allowing them to reach the lesion site and effectively kill the fungi. The results both in vitro and in vivo demonstrated that it exhibited good biocompatibility and antifungal activity, significantly improving the therapeutic effect in a mouse model of FK. Therefore, this biophilic ultrasmall size and positive carbon dot, characterized by its ability to penetrate the corneal barrier and its antifungal properties, may offer valuable insights into the design of effective ocular nanomedicines.

Antibiotic Delivery System for Treating Bacteria-Induced Anterior Blepharitis.

The eyelid-related disease of blepharitis remains a tricky ocular disorder and affects patient compliance. However, there is no available and effective treatment, making it extremely challenging. Herein, an antibacterial system based on antibiotic delivery was developed and applied in a blepharitis model induced by bacteria. The antibacterial tests against Staphylococcus aureus both in vitro and in vivo demonstrated that the system shows a favorable bactericidal effect. Then, histological evaluation indicated that the system shows both antibacterial and anti-inflammatory effects. This facile design provided an effective ocular infection management, which displays a promising prospect while addressing other complex ocular disorders.

Precision Dosing of Antibiotics and Potentiators by Hypoxia-Responsive Nanoparticles for Overcoming Antibiotic Resistance in Gram-Negative Bacteria.

The stalling development of antibiotics, especially against intrinsically resistant Gram-negative pathogens associated with outer membranes, leads to an emerging antibiotic crisis across the globe. To breathe life into existing drugs, we herein report a hypoxia-responsive nanoparticle (NP) that encapsulates a hydrophobic antibiotic, rifampicin, and a cationic potentiator, polysulfonium. The simultaneous release of antibiotics and potentiators can be promoted and inhibited in response to the severity of bacterial-induced hypoxia, leading to antimicrobial dosing in a precision manner. Under the synergism of polysulfoniums with membrane-disruption capability, the NPs can intensively decrease the antibiotic dose by up to 66-95% in eliminating planktonic Gram-negative P. aeruginosa bacteria and achieve an 8-log reduction of bacteria in mature biofilms at rifampicin MIC. The NP formulation demonstrates that precision dosing of antibiotics and potentiators regulated by hypoxia provides a promising strategy to maximize efficacy and minimize toxicity in treating Gram-negative bacterial infection.

Celastrol Alleviates Corneal Stromal Fibrosis by Inhibiting TGF-ß1/Smad2/3-YAP/TAZ Signaling After Descemet Stripping Endothelial Keratoplasty.

Purpose: The purpose of this study was to investigate the effect of celastrol (CEL) on corneal stromal fibrosis after Descemet stripping endothelial keratoplasty (DSEK) and its associated mechanism. Methods: Rabbit corneal fibroblasts (RCFs) were isolated, cultured, and identified. A CEL-loaded positive nanomedicine (CPNM) was developed to enhance corneal penetration. CCK-8 and scratch assays were performed to evaluate cytotoxicity and the effects of CEL on the migration of RCFs. The RCFs were activated by TGF-ß1 with or without CEL treatment, and then the protein expression levels of TGFßRII, Smad2/3, YAP, TAZ, TEAD1, α-SMA, TGF-ß1, FN, and COLI were assessed by immunofluorescence or Western blotting (WB). An in vivo DSEK model was established in New Zealand White rabbits. The corneas were stained using H&E, YAP, TAZ, TGF-ß1, Smad2/3, TGFßRII, Masson, and COLI. H&E staining of the eyeball was performed to assess the tissue toxicity of CEL at 8 weeks after DSEK. Results: In vitro CEL treatment inhibited the proliferation and migration of RCFs induced by TGF-ß1. Immunofluorescence and WB showed that CEL significantly inhibited the protein expression of TGF-ß1, Smad2/3, YAP, TAZ, TEAD1, α-SMA, TGF-ßRII, FN, and COL1 induced by TGF-ß1 in RCFs. In the rabbit DSEK model, CEL significantly reduced the levels of YAP, TAZ, TGF-ß1, Smad2/3, TGFßRII, and collagen. No obvious tissue toxicity was observed in the CPNM group. Conclusions: CEL effectively inhibited corneal stromal fibrosis after DSEK. The TGF-ß1/Smad2/3-YAP/TAZ pathway may be involved in the mechanism by which CEL alleviates corneal fibrosis. The CPNM is a safe and effective treatment strategy for corneal stromal fibrosis after DSEK.

Celastrol-based nanomedicine hydrogels eliminate posterior capsule opacification.

Aim: To formulate an injectable thermosensitive micelle-hydrogel hybrid system loaded with celastrol (celastrol-loaded micelle hydrogel: CMG) to prevent posterior capsule opacification (PCO). Materials & methods: Celastrol-loaded micelles were embedded in a thermosensitive hydrogel matrix to enable controlled on-demand celastrol delivery into the residual capsule. The efficacy and mechanisms of the system for eliminating PCO were evaluated in rabbits. Results: Celastrol-loaded micelles inhibited the migration and proliferation of lens epithelial cells induced by TGF-ß1. Celastrol prevents epithelial-mesenchymal transition in lens epithelial cells induced by TGF-ß1 through the TGF-ß1/Smad2/3/TEAD1 signaling pathway. In vivo efficiency evaluations showed that CMG demonstrated an excellent inhibitory effect on PCO in rabbits and had no obvious tissue toxicity. Conclusion: Injectable CMG may represent a promising ophthalmic platform for preventing PCO. This versatile injectable micelle-hydrogel hybrid represents a clinically relevant platform to achieve localized therapy and controlled release of drugs in other disease therapies.

A dual-functional chitosan derivative platform for fungal keratitis.

Fungal keratitis remains a serious infectious ocular disease, and the traditional administration of eye drops is limited by ocular intrinsic barriers and drug shortages. Herein, we fabricated a chitosan-based dual-functional platform for ocular topical delivery of econazole. The platform can prolong the residence time on the ocular surface due to its strong interaction with the mucin layer by physical adhesion and covalent bonding, and also open corneal epithelial tight junctions for being positively charged, thereby enhancing corneal penetration of drug. Using these strategies, dosing concentration was reduced from 0.3 wt% to 0.1 wt%, dosing frequency was reduced from once-an-hour to twice-daily, in vitro and in vivo antifungal therapeutic effects were achieved and patient compliance could be improved. Given its high structural adaptability, many other ocular anterior segment-related diseases would benefit from this platform.

A lingering mouthwash with sustained antibiotic release and biofilm eradication for periodontitis.

Dental plaque biofilms are believed to be one of the principal virulence factors in periodontitis resulting in tooth loss. Traditional mouthwashes are limited due to the continuous flow of saliva and poor drug penetration ability in the biofilm. Herein, we fabricated an antibiotic delivery platform based on natural polysaccharides (chitosan and cyclodextrin) as a novel mouthwash for the topical cavity delivery of minocycline. The penetration and residence mechanisms demonstrate that the platform can prolong the residence time up to 12 h on biofilms. Furthermore, sustained release can enhance the penetration of drugs into biofilms. In vitro antibiofilm experimental results indicated that the mouthwash effectively kills bacteria and eradicate biofilms. Effective treatment in vivo was confirmed by the significantly reduced dental plaque and alleviated inflammation observed in a rat periodontitis model. In summary, this novel platform can improve antibiofilm efficiency and prevent drugs from being washed away by saliva, which may provide benefits for many oral infectious diseases.

Ca2+-supplying black phosphorus-based scaffolds fabricated with microfluidic technology for osteogenesis.

Effective osteogenesis remains a challenge in the treatment of bone defects. The emergence of artificial bone scaffolds provides an attractive solution. In this work, a new biomineralization strategy is proposed to facilitate osteogenesis through sustaining supply of nutrients including phosphorus (P), calcium (Ca), and silicon (Si). We developed black phosphorus (BP)-based, three-dimensional nanocomposite fibrous scaffolds via microfluidic technology to provide a wealth of essential ions for bone defect treatment. The fibrous scaffolds were fabricated from 3D poly (l-lactic acid) (PLLA) nanofibers (3D NFs), BP nanosheets, and hydroxyapatite (HA)-porous SiO2 nanoparticles. The 3D BP@HA NFs possess three advantages: i) stably connected pores allow the easy entrance of bone marrow-derived mesenchymal stem cells (BMSCs) into the interior of the 3D fibrous scaffolds for bone repair and osteogenesis; ii) plentiful nutrients in the NFs strongly improve osteogenic differentiation in the bone repair area; iii) the photothermal effect of fibrous scaffolds promotes the release of elements necessary for bone formation, thus achieving accelerated osteogenesis. Both in vitro and in vivo results demonstrated that the 3D BP@HA NFs, with the assistance of NIR laser, exhibited good performance in promoting bone regeneration. Furthermore, microfluidic technology makes it possible to obtain high-quality 3D BP@HA NFs with low costs, rapid processing, high throughput and mass production, greatly improving the prospects for clinical application. This is also the first BP-based bone scaffold platform that can self-supply Ca2+, which may be the blessedness for older patients with bone defects or patients with damaged bones as a result of calcium loss.

Co-Delivery of Paclitaxel and siRNA with pH-Responsive Polymeric Micelles for Synergistic Cancer Therapy.

Due to the complex physiological characteristics of tumors, chemotherapy or gene therapy alone cannot completely kill tumor cells. Therefore, combining chemotherapy with gene therapy for combination therapy is the key to solving this problem. However, there are still significant challenges in how to simultaneously deliver and rapidly release the drugs and siRNA into cancer cells. In this work, a triblock copolymer was synthesized to co-deliver siRNA and paclitaxel to tumor cells. This system has an acid-sensitive subsurface layer, which can not only load siRNA to prevent premature drug release but also has good controlled release performance. In vitro experiments showed that polymeric vectors can efficiently deliver siRNA and paclitaxel simultaneously into tumor cells for rapid release within the tumor cells. This study reveals that this novel polymeric micelle is a suitable vector for the codelivery of chemotherapeutic drugs and siRNA to cancer cells, representing an important advance in nanotechnology, nanomedicine, drug delivery, and cancer therapy.

Inflammation-Targeted Celastrol Nanodrug Attenuates Collagen-Induced Arthritis through NF-κB and Notch1 Pathways.

Rheumatoid arthritis (RA) is a systemic inflammatory disorder which can cause bone and cartilage damage leading to disability, yet the treatment remains unsatisfactory nowadays. Celastrol (Cel) has shown antirheumatic activity against RA. However, the frequent parenteral delivery and poor water solubility of Cel restrict its further therapeutic applications. Here, aiming at effectively overcoming the poor water solubility and short half-life of Cel to boost its beneficial effects for treating RA, we developed a polymeric micelle for Cel delivery based on a reactive oxygen species (ROS) sensitive polymer. Our results demonstrated that Cel may inhibit the repolarization of macrophages toward the pro-inflammatory M1 pheno-type via regulating the NF-κB and Notch1 pathways, which resulted in significantly decreased secretion of multiple pro-inflammatory cytokines to suppress the RA progression. Consequently, the Cel-loaded micelle effectively alleviated the major RA-associated symptoms including articular scores, ankle thickness, synovial inflammation, bone erosion, and cartilage degradation.

Antiangiogenic and Antitumor Therapy for Retinoblastoma with Hypoxia-Inducible Factor-1α siRNA and Celastrol Co-Delivery Nanomicelles.

Retinoblastoma (RB) makes up about 3% of all childhood malignancies. Chemotherapy is commonly applied for RB treatment, while the clinical effectiveness varies significantly due to the cancer therapeutic resistances. Hypoxic tumor microenvironment, a hallmark of all tumors, is strongly associated with malignant progress and therapeutic resistances. The hypoxia mainly promotes the angiogenesis by upregulating pro-angiogenetic pathways. In this work, polymeric micelles are used as the carrier to deliver celastrol and siRNA to RB cells for achieving synergistic anti-tumor and antiangiogenesis effects. The micelle vectors have shown effective cellular internalization and release of loaded-celastrol and HIF-1 siRNA. The co-delivery system specifically and synergistically inhibits the expression of HIF-1α and VEGF in RB cells, suppresses the HIF-1α /VEGF/VEGFR signaling pathway, and impedes the proliferation, migration, and invasion of vascular endothelial cells. The polymer micellar carrier that co-delivers HIF-1α siRNA and celastrol is used for antiangiogenic and antitumor therapy of RB. Altogether, the results show that our polymeric micelle delivery system can be used to overcome barriers of drug resistance induced by angiogenesis and develop new drug/siRNA combinatory therapies.

Biocompatible and Biodegradable 3D Double-Network Fibrous Scaffold for Excellent Cell Growth.

Fibrous scaffold could provide extracellular matrix (ECM) like structure and desired network for cell growth; however, the mechanical performance of this type uni-structured fibrous scaffold cannot meet the requirement of tissue formation. Therefore, new strategies are needed for form mechanical strength enhancement. In this study, we developed three dimensional double-network structured fibrous scaffold (3D DN-Fs) using self-assembly technology combined with electrospinning technology. Our 3D DN-Fs consists of two types of skeletons: the finer silk nanofibers which can mimic biocompatible ECM structure; and the larger skeletal fibrous layers can greatly improve the mechanical strength and cellular loading ability, and provide good nutrition and excreta delivery system for cell growth. Therefore, our 3D DN-Fs displayed excellent mechanical performance (more than 50% increment), biocompatibility, biodegradability, and a desirable microenvironment for cell growth. More importantly, cultured cells exhibited excellent viability and 3D growth. Our novel strategy greatly enhances the potential application of fibrous scaffold in the biomedical area, such as 3D cell culture and tissue engineering.