Epithelium-Penetrable Nanoplatform with Enhanced Antibiotic Internalization for Management of Bacterial Keratitis.

A standardized regimen for addressing the adverse effects of bacterial keratitis on vision remains an intractable challenge due to poor epithelial penetration and a short corneal retention time. In this study, a new strategy is proposed to implement the direct transport of antibiotics to bacteria-infected corneas via topical administration of an epithelium-penetrable biodriven nanoplatform, thereby enabling the efficacious treatment of bacterial keratitis. The nanoplatforms were composed of amphiphilic glycopolymers containing boron dipyrromethene and boronic acid moieties with stable fluorescence characteristics and the ability to potentiate epithelial penetration deep into the cornea. The boronic acid-derived nanoplatforms enabled efficient cellular internalization through the high affinity of boric acid groups for the diol-containing bacterial cell wall, resulting in enhanced drug penetration and retention inside the pathogenic bacteria. The bacterial cells formed agglomerations after incorporating the nanoplatforms along with a special mechanism to release the encapsulated cargo in response to in situ bacteria. Compared with the drug alone, this smart system achieved enhanced bacterial mortality and attenuated inflammation associated with Staphylococcus aureus-induced keratitis in rats, demonstrating a paradigm for targeted ocular drug delivery and an alternative strategy for managing bacterial keratitis or other bacterial infections by heightening corneal permeability and transcorneal bioavailability.

Glycosylated Nanotherapeutics with ß-Lactamase Reversible Competitive Inhibitory Activity Reinvigorates Antibiotics against Gram-Negative Bacteria.

Antibiotics are currently first-line therapy for bacterial infections. However, the curative effect of antibiotic remedies is limited due to increasingly prevalent bacterial resistance. The strategy to reverse intrinsic acquired drug resistance presents a promising option for reinvigorating antibiotic therapy. Here, we developed a ß-lactamase-inhibiting macromolecule composed of benzoxaborole and dextran for precise transport of ß-lactam antibiotics to strains overexpressing ß-lactamase. Benzoxaborole-derived nanotherapeutics enabled specific recognition and rapid internalization, and the nanotherapeutics with a high affinity toward bacteria distinctly inhibited the catalytic activity of bacterially secreted ß-lactamase by a reversible competitive mechanism. Thus, the system entrapping cefoxitin harbored a significantly enhanced ability to kill drug-resistant Escherichia coli compared to the ability of the drug by specifically overcoming the membrane barrier and acquired resistance mechanism of ß-lactamase overproduction. The reversible competitive nanotherapeutics exhibited a robust therapeutic efficacy in rat wounds infected with drug-resistant bacteria; the efficacy was due to efficient bacterial elimination and collateral benzoxaborole-dependent amelioration of the inflammatory response. The above results offered insights into the facile design of precise macromolecular adjuvants to exclusively reverse the acquired bacterial resistance mechanism and increase the utility of antibiotic therapies against antibiotic-resistant bacterial infections.

Glycomimetic-Conjugated Photosensitizer for Specific Pseudomonas aeruginosa Recognition and Targeted Photodynamic Therapy.

Due to the rapid development of bacterial resistance, there is an urgent need to explore new antibacterial agents to substitute for traditional antibiotic therapy. Photodynamic therapy has been identified as a promising bactericidal method to conquer antibiotic-resistant pathogens. To solve the problem of photosensitizer damage to normal tissues in vivo, we developed a boron-dipyrrolemethene (BODIPY)-based glycosylated photosensitizer for ablating Pseudomonas aeruginosa ( P. aeruginosa). This glycosylated photosensitizer exhibited good water solubility and generated 1O2 rapidly in an aqueous solution under light exposure. The photosensitizer did not cause detectable toxicity to human cells in the dark. Importantly, the photosensitizer was able to selectively attach to P. aeruginosa over normal cells, thus resulting in effective pathogen ablation by reactive oxygen species. Moreover, the photosensitizer inhibited over 90% of the biofilm formation produced by P. aeruginosa. The results indicate that the design of the macromolecular photosensitizer-induced bacterial death and inhibited biofilm formation provide a novel strategy for overcoming bacterial infection.

A Water-Soluble Galactose-Decorated Cationic Photodynamic Therapy Agent Based on BODIPY to Selectively Eliminate Biofilm.

A multitude of serious chronic infections are involved in bacterial biofilms that are difficult to eradicate. Here, a water-soluble galactose-functionalized cationic 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based photodynamic therapy agent was synthesized for selectively eliminating the bacterial biofilm. These conjugates can capture bacteria to form aggregations through electrostatic interaction and then generate a large number of reactive oxygen species (ROS) under visible light irradiation to kill the bacteria without the emergence of bacterial resistance. Simultaneously, this agent could effectively inhibit and eradicate both Gram-positive and Gram-negative bacterial biofilms. The in-depth analysis of the antimicrobial mechanism confirmed that the conjugates can quickly bind on the bacterial surface, irreversibly disrupt the bacterial membrane, and distinctly inhibit intracellular enzyme activity, ultimately leading to the bacterial death. Importantly, these conjugates are highly selective toward bacterial cells over mammalian cells as well as no cytotoxicity to A549 cells and no discernible hemolytic activity. Collectively, this water-soluble galactose-decorated cationic BODIPY-based photodynamic therapy agent design provides promising insights for the development of therapy for antibiotic-resistant bacteria.

Engineering lauric acid-based nanodrug delivery systems for restoring chemosensitivity and improving biocompatibility of 5-FU and OxPt against Fn-associated colorectal tumor.

Colorectal cancer (CRC) occurs in the colorectum and ranks second in the global incidence of all cancers, accounting for one of the highest mortalities. Although the combination chemotherapy regimen of 5-fluorouracil (5-FU) and platinum(IV) oxaliplatin prodrug (OxPt) is an effective strategy for CRC treatment in clinical practice, chemotherapy resistance caused by tumor-resided Fusobacterium nucleatum (Fn) could result in treatment failure. To enhance the efficacy and improve the biocompatibility of combination chemotherapy, we developed an antibacterial-based nanodrug delivery system for Fn-associated CRC treatment. A tumor microenvironment-activated nanomedicine 5-FU-LA@PPL was constructed by the self-assembly of chemotherapeutic drug derivatives 5-FU-LA and polymeric drug carrier PPL. PPL is prepared by conjugating lauric acid (LA) and OxPt to hyperbranched polyglycidyl ether. In principle, LA is used to selectively combat Fn, inhibit autophagy in CRC cells, restore chemosensitivity of 5-FU as well as OxPt, and consequently enhance the combination chemotherapy effects for Fn-associated drug-resistant colorectal tumor. Both in vitro and in vivo studies exhibited that the tailored nanomedicine possessed efficient antibacterial and anti-tumor activities with improved biocompatibility and reduced non-specific toxicity. Hence, this novel anti-tumor strategy has great potential in the combination chemotherapy of CRC, which suggests a clinically relevant valuable option for bacteria-associated drug-resistant cancers.

Emerging strategies for combating Fusobacterium nucleatum in colorectal cancer treatment: Systematic review, improvements and future challenges.

Colorectal cancer (CRC) is generally characterized by a high prevalence of Fusobacterium nucleatum (F. nucleatum), a spindle-shaped, Gram-negative anaerobe pathogen derived from the oral cavity. This tumor-resident microorganism has been closely correlated with the occurrence, progression, chemoresistance and immunosuppressive microenvironment of CRC. Furthermore, F. nucleatum can specifically colonize CRC tissues through adhesion on its surface, forming biofilms that are highly resistant to commonly used antibiotics. Accordingly, it is crucial to develop efficacious non-antibiotic approaches to eradicate F. nucleatum and its biofilms for CRC treatment. In recent years, various antimicrobial strategies, such as natural extracts, inorganic chemicals, organic chemicals, polymers, inorganic-organic hybrid materials, bacteriophages, probiotics, and vaccines, have been proposed to combat F. nucleatum and F. nucleatum biofilms. This review summarizes the latest advancements in anti-F. nucleatum research, elucidates the antimicrobial mechanisms employed by these systems, and discusses the benefits and drawbacks of each antimicrobial technology. Additionally, this review also provides an outlook on the antimicrobial specificity, potential clinical implications, challenges, and future improvements of these antimicrobial strategies in the treatment of CRC.

A gene delivery system with autophagy blockade for enhanced anti-angiogenic therapy against Fusobacterium nucleatum-associated colorectal cancer.

Anti-angiogenesis has emerged a promising strategy against colorectal cancer (CRC). However, the efficacy of anti-angiogenic therapy is greatly compromised by the up-regulated autophagy levels resulting from the evolutionary resistance mechanism and the presence of Fusobacterium nucleatum (F. nucleatum) in CRC. Herein, we report a cationic polymer capable of blocking autophagic flux to deliver plasmid DNA (pDNA) encoding soluble FMS-like tyrosine kinase-1 (sFlt-1) for enhanced anti-angiogenic therapy against F. nucleatum-associated CRC. The autophagy-inhibiting cationic polymer, referred to as PNHCQ, is synthesized by conjugating hydroxychloroquine (HCQ) into 3,3'-diaminodipropylamine-pendant poly(ß-benzyl-L-aspartate) (PAsp(Nors)), which can be assembled and electrostatically interacted with sFlt-1 plasmid to form PNHCQ/sFlt-1 polyplexes. Hydrophobic HCQ modification not only boosts transfection efficiency but confers autophagy inhibition activity to the polymer. Hyaluronic acid (HA) coating is further introduced to afford PNHCQ/sFlt-1@HA for improved tumor targeting without compromising on transfection. Consequently, PNHCQ/sFlt-1@HA demonstrates significant anti-tumor efficacy in F. nucleatum-colocalized HT29 mouse xenograft model by simultaneously exerting anti-angiogenic effects through sFlt-1 expression and down-regulating autophagy levels exacerbated by F. nucleatum challenge. The combination of anti-angiogenic gene delivery and overall autophagy blockade effectively sensitizes CRC tumors to anti-angiogenesis, providing an innovative approach for enhanced anti-angiogenic therapy against F. nucleatum-resident CRC. STATEMENT OF SIGNIFICANCE: Up-regulated autophagy level within tumors is considered responsible for the impaired efficacy of clinic antiangiogenic therapy against CRC colonized with pathogenic F. nucleatum. To tackle this problem, an autophagy-inhibiting cationic polymer is developed to enable efficient intracellular delivery of plasmid DNA encoding soluble FMS-like tyrosine kinase-1 (sFlt-1) and enhance anti-angiogenic therapy against F. nucleatum-associated CRC. HA coating that can be degraded by tumor-enriching hyaluronidase is further introduced for improved tumor targeting without compromising transfection efficiency. The well-orchestrated polyplexes achieve considerable tumor accumulation, efficient in vivo transfection, and effectively reinforce the sensitivity of CRC to the sFlt-1-derived anti-angiogenic effects by significantly blocking overall autophagy flux exacerbated by F. nucleatum challenge, thus harvesting robust antitumor outcomes against F. nucleatum-resident CRC.

Amphiphilic polymeric nanodrug integrated with superparamagnetic iron oxide nanoparticles for synergistic antibacterial and antitumor therapy of colorectal cancer.

Colorectal cancer (CRC) is one of the most prevalent and deadly malignancies that can be influenced by Fusobacterium nucleatum (Fn), a bacterium that promotes tumor development and chemoresistance, resulting in limited therapeutic efficacy. Traditional antibiotics cannot effectively eliminate Fn at tumor site due to issues like biofilm formation, while chemotherapy alone fails to suppress tumor progression. Therefore, the development of new methods to eliminate Fn and promote antitumor efficacy is of great significance for improving the outcome of CRC treatment. Herein, we developed a nanodrug (OPPL) that integrates oleic acid-modified superparamagnetic iron oxide nanoparticles (O-SPIONs) and an amphiphilic polymer (PPL) to deliver the platinum prodrug and antimicrobial lauric acid (LA) for enhancing the treatment of CRC. We demonstrated that OPPL can synergistically enhance antibacterial and biofilm disruption activities against Fn along with the antimicrobial LA by producing reactive oxygen species (ROS) through its peroxidase-like activity. Furthermore, the OPPL nanodrug can increase intracellular ROS, promote lipid peroxides and deplete glutathione, leading to ferroptosis. By combining chemotherapy and induced ferroptosis, the OPPL nanodrug exhibited high cytotoxicity against CRC cells. In vivo studies showed that the OPPL nanodrug could enhance tumor accumulation, enable magnetic resonance imaging, suppresse tumor growth, and inhibit growth of intratumor Fn. These results suggest that OPPL is an effective and promising candidate for the treatment of Fn-infected CRC. STATEMENT OF SIGNIFICANCE: The enrichment of Fusobacterium nucleatum (Fn) in colorectal cancer is reported to exacerbate tumor malignancy and is particularly responsible for chemoresistance. To this respect, we strategically elaborated multifaceted therapeutics, namely OPPL nanodrug, combining oleic acid-modified superparamagnetic iron oxide nanoparticles (O-SPIONs) with a polymer containing a platinum prodrug and antimicrobial lauric acid. The O-SPION components exert distinctive peroxidase-like activity, capable of stimulating Fenton reactions selectively in the tumor microenvironment, consequently accounting for the progressive production of reactive oxygen species. Hence, O-SPIONs have been demonstrated to not only supplement the antimicrobial activities of lauric acid in overcoming Fn-induced chemoresistance but also stimulate potent tumor ferroptosis. Our proposed dual antimicrobial and chemotherapeutic nanodrug provides an appreciable strategy for managing challenging Fn-infected colorectal cancer.

Remotely Controllable Supramolecular Nanomedicine for Drug-Resistant Colorectal Cancer Therapy Caused by Fusobacterium nucleatum.

Fusobacterium nucleatum (Fn) existing in the community of colorectal cancer (CRC) promotes CRC progression and causes chemotherapy resistance. Despite great efforts that have been made to overcome Fn-induced chemotherapy resistance by co-delivering antibacterial agents and chemotherapeutic drugs, increasing the drug-loading capacity and enabling controlled release of drugs remain challenging. In this study, a novel supramolecular upconversion nanoparticle (SUNP) is constructed by incorporating a positively charged polymer (PAMAM-LA-CD) with Fn inhibition capacity, a negatively charged platinum (IV) oxaliplatin prodrug (OXA-COOH), upconversion nanoparticle (UCNPs) and polyethylene glycol-azobenzene (PEG-Azo) to enhance drug-loading and enable on-demand drug release for drug-resistant CRC treatment. SUNPs exhibit high drug-loading capacity (30.8%) and good structural stability under normal physiological conditions, while disassembled upon exogenous NIR excitation and endogenous azo reductase in the CRC microenvironment to trigger drug release. In vitro and in vivo studies demonstrate that SUNPs presented good biocompatibility and robust performance to overcome chemoresistance, thereby significantly inhibiting Fn-infected cancer cell proliferation. This study leverages multiple dynamic chemical designs to integrate both advantages of drug loading and release in a single system, which provides a promising candidate for precision therapy of bacterial-related drug-resistant cancers.

Construction of Iron-Scavenging Hydrogel via Thiol-Ene Click Chemistry for Antibiotic-Free Treatment of Bacterial Wound Infection.

Bacteria, especially drug-resistant strains, can quickly cause wound infections, leading to delayed healing and fatal risk in clinics. With the growing need for alternative antibacterial approaches that rely less on antibiotics or eliminate their use altogether, a novel antibacterial hydrogel named Ovtgel is developed. Ovtgel is formulated by chemically crosslinking thiol-modified ovotransferrin (Ovt), a member of the transferrin family found in egg white, with olefin-modified agarose through thiol-ene click chemistry. Ovt is designed to sequester ferric ions essential for bacterial survival and protect wound tissues from damages caused by the reactive oxygen species (ROS) generated in Fenton reactions. Experimental data have shown that Ovtgel significantly enhances wound healing by inhibiting bacterial growth and shielding tissues from ROS-induced harms. Unlike traditional antibiotics, Ovtgel targets essential trace elements required for bacterial survival in the host environment, preventing the development of drug resistance in pathogenic bacteria. Ovtgel exhibits excellent biocompatibility due to the homology of Ovt to mammalian transferrin. This hydrogel has the potential to serve as an effective antibiotic-free solution for combating bacterial infections.

In situ-activated photothermal nanoplatform for on-demand NO gas delivery and enhanced colorectal cancer treatment.

The naturally evolved and intestinal pathogenic Fusobacterium nucleatum (Fn)-induced drug resistance profoundly impaired the efficacy of chemotherapy against colorectal cancer (CRC). Alternative treatment modalities against Fn-associated CRC are desperately needed. Herein, we engineer an in situ-activated anti-tumor and antibacterial nanoplatform (Cu2O/BNN6@MSN-Dex) to allow photoacoustic (PA) imaging-guided photothermal and NO gas combinatorial therapy for enhanced Fn-associated CRC treatment. The nanoplatform is constructed by loading cuprous oxide (Cu2O) and nitric oxide (NO) donor (BNN6) into dextran-decorated mesoporous silica nanoparticles (MSN), which is finally surface-functionalized with dextran via dynamic boronate linkage. Cu2O can be sulfuretted in situ by endogenous hydrogen sulfide overexpressed in CRC to produce copper sulfide with remarkable PA and photothermal properties, enabling the generation of NO from BNN6 under 808 nm laser irradiation, which is eventually triggered to release by multiple biological cues in the tumor microenvironment. Cu2O/BNN6@MSN-Dex exhibits superior biocompatibility, as well as H2S-triggered near-infrared-controlled antibacterial and anti-tumor performance in vitro and in vivo via photothermal and NO gas combination therapy. Furthermore, Cu2O/BNN6@MSN-Dex provokes systemic immune responses, thereby promoting anti-tumor efficacy. This study provides a conbinational strategy to effectively inhibit tumors and intratumor pathogens for enhanced CRC treatment.

Polymeric nano-system for macrophage reprogramming and intracellular MRSA eradication.

Intracellular Methicillin-Resistant Staphylococcus aureus (MRSA) remains a major factor of refractory and recurrent infections, which cannot be well addressed by antibiotic therapy. Here, we design a cellular infectious microenvironment-activatable polymeric nano-system to mediate targeted intracellular drug delivery for macrophage reprogramming and intracellular MRSA eradication. The polymeric nano-system is composed of a ferrocene-decorated polymeric nanovesicle formulated from poly(ferrocenemethyl methacrylate)-block-poly(2-methacryloyloxyethyl phosphorylcholine) (PFMMA-b-PMPC) copolymer with co-encapsulation of clofazimine (CFZ) and interferon-γ (IFN-γ). The cellular-targeting PMPC motifs render specific internalization by macrophages and allow efficient intracellular accumulation. Following the internalization, the ferrocene-derived polymer backbone sequentially undergoes hydrophobic-to-hydrophilic transition, charge reversal and Fe release in response to intracellular hydrogen peroxide over-produced upon infection, eventually triggering endosomal escape and on-site cytosolic drug delivery. The released IFN-γ reverses the immunosuppressive status of infected macrophages by reprogramming anti-inflammatory M2 to pro-inflammatory M1 phenotype. Meanwhile, intracellular Fe2+-mediated Fenton reaction together with antibiotic CFZ contributes to increased intracellular hydroxyl radical (•OH) generation. Ultimately, the nano-system achieves robust potency in ablating intracellular MRSA and antibiotic-tolerant persisters by synchronous immune modulation and efficient •OH killing, providing an innovative train of thought for intracellular MRSA control.

An orally delivered bacteria-based coacervate antidote for alcohol detoxification.

Alcohol intoxication causes serious diseases, whereas current treatments are mostly supportive and unable to convert alcohol into nontoxic products in the digestive tract. To address this issue, an oral intestinal-coating coacervate antidote containing acetic acid bacteria (AAB) and sodium alginate (SA) mixture was constructed. After oral administration, SA reduces absorption of ethanol and promotes the proliferation of AAB, and AAB converts ethanol to acetic acid or carbon dioxide and water by two sequential catalytic reactions in the presence of membrane-bound alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). In vivo study shows that the bacteria-based coacervate antidote can significantly reduce the blood alcohol concentration (BAC) and effectively alleviates alcoholic liver injury in mice. Given the convenience and effectiveness of oral administration, AAB/SA can be used as a promising candidate antidote for relieving alcohol-induced acute liver injury.

In Situ Sprayed Biotherapeutic Gel Containing Stable Microbial Communities for Efficient Anti-Infection Treatment.

Systematic administration of antibiotics to treat infections often leads to the rapid evolution and spread of multidrug-resistant bacteria. Here, an in situ-formed biotherapeutic gel that controls multidrug-resistant bacterial infections and accelerates wound healing is reported. This biotherapeutic gel is constructed by incorporating stable microbial communities (kombucha) capable of producing antimicrobial substances and organic acids into thermosensitive Pluronic F127 (polyethylene-polypropylene glycol) solutions. Furthermore, it is found that the stable microbial communities-based biotherapeutic gel possesses a broad antimicrobial spectrum and strong antibacterial effects in diverse pathogenic bacteria-derived xenograft infection models, as well as in patient-derived multidrug-resistant bacterial xenograft infection models. The biotherapeutic gel system considerably outperforms the commercial broad-spectrum antibacterial gel (0.1% polyaminopropyl biguanide) in pathogen removal and infected wound healing. Collectively, this biotherapeutic strategy of exploiting stable symbiotic consortiums to repel pathogens provides a paradigm for developing efficient antibacterial biomaterials and overcomes the failure of antibiotics to treat multidrug-resistant bacterial infections.

Harnessing in situ glutathione for effective ROS generation and tumor suppression via nanohybrid-mediated catabolism dynamic therapy.

The overexpression of glutathione (GSH) in cancer cells has long been regarded as the primary obstacle for reactive oxygen species (ROS)-involved anti-tumor therapies. To solve this issue, a ferric ion and selenite-codoped calcium phosphate (Fe/Se-CaP) nanohybrid here is fabricated to catabolize endogenous GSH, instead of directly deleting it, to trigger a ROS storm for tumor suppression. The selenite component in Fe/Se-CaP can catabolize GSH to superoxide anion (O2•-) and hydroxyl radicals (•OH) via cascade catalytic reactions, elevating oxidative stress while destroying antioxidant system. The doped Fe can further catalyze the soaring hydrogen peroxide (H2O2) originated from O2•- to •OH via Fenton reactions. Collectively, Fe/Se-CaP mediated self-augmented catabolism dynamic therapy finally induces apoptosis of cancer cells owing to the significant rise of ROS and, combined with CaP adjuvant, evokes adaptive immune responses to suppress tumor progression, providing an innovative train of thought for ROS-involved anti-tumor therapies.

Polymeric PD-L1 blockade nanoparticles for cancer photothermal-immunotherapy.

Checkpoint inhibitors, such as antibodies blocking the PD-1/PD-L1 pathway, are among the most promising immunotherapies to treat metastatic cancers, but their response rate remains low. In addition, the usage of monoclonal antibodies as checkpoint inhibitors is associated with a series of drawbacks. Herein, an all synthetic nanoparticle with PD-L1 blockade capability is developed for cancer photothermal-immunotherapy. The polymeric nanoparticle integrates photothermal treatment, antitumor vaccination, and PD-1/PD-L1 blockade in a single system to augment the antitumor efficacy. In a CT26 bilateral tumor model, intravenously injected nanoparticles accumulate in tumor sites and mediate strong photothermal effects, eradicate the NIR treated primary tumors and elicit strong antitumor immunity by inducing immunogenic cell death (ICD). Growth of the untreated distant tumors is also suppressed due to the synergies of systemic antitumor immune activation and PD-L1 blockade. Our strategy offers a simple but promising approach for the treatment of metastatic cancer.

A bioinspired hierarchical nanoplatform targeting and responding to intracellular pathogens to eradicate parasitic infections.

Intracellular bacteria-mediated antibiotic tolerance, which acts as a "Trojan horse," plays a critical and underappreciated role in chronic and recurrent infections. Failure of conventional antibiotic therapy is often encountered because infected cells prevent drug permeation or the drug concentration is too low at the site of resident bacteria. New paradigms are therefore urgently needed for intracellular anti-infective therapy. Here, a novel therapeutic was developed for targeted delivery of antibiotics into bacteria-infected macrophages to improve drug accumulation in intracellular niches and bactericidal activity of antibiotics against intracellular pathogens. This hierarchical nanoplatform includes a glycocalyx-mimicking shell that enables rapid uptake by macrophages. Subsequently, the targeting moieties are activated in response to the bacteria, and the release of entrapped antibiotics is triggered by bacteria and bacteria-secreted enzymes. The self-immolative drug delivery nanoplatform eliminates intracellular pathogenic bacteria residing in macrophages more efficiently compared to drugs alone. The in vivo dynamically monitored nanosystem also efficiently inhibited the growth of intracellular Staphylococcus aureus in infected muscles of mice with negligible systemic toxicity. The novel dual-targeting design of an all-in-one therapeutic platform can be used as an alternative strategy to reanimate antibiotic therapy against multifarious intracellular bacterial infections.

NIR-activated nanosystems with self-modulated bacteria targeting for enhanced biofilm eradication and caries prevention.

The efficacious delivery of antimicrobial drugs to intractable oral biofilms remains a challenge due to inadequate biofilm penetration and lack of pathogen targeting. Herein, we have developed a microenvironment-activated poly(ethylene glycol) (PEG)-sheddable nanoplatform to mediate targeted delivery of drugs into oral biofilms for the efficient prevention of dental caries. The PEGylated nanoplatform with enhanced biofilm penetration is capable of deshielding the PEG layer under slightly acidic conditions in a PEG chain length-dependent manner to re-expose the bacteria-targeting ligands, thereby facilitating targeted codelivery of ciprofloxacin (CIP) and IR780 to the bacteria after accumulation within biofilms. The nanoplatform tends to induce bacterial agglomeration and suffers from degradation in the acidic oral biofilm microenvironment, triggering rapid drug release on demand around bacterial cells. The self-modulating nanoplatform under near-infrared (NIR) irradiation accordingly displays greatly augmented potency in oral biofilm penetration and disruption compared with drugs alone. Topical oral treatment with nanoplatforms involving synergetic pharmacological and photothermal/photodynamic trinary therapy results in robust biofilm dispersion and efficacious suppression of severe tooth decay in rats. This versatile nanoplatform can promote local accumulation and specific drug transport into biofilms and represents a new paradigm for targeted drug delivery for the management of oral biofilm-associated infections.

Bioadhesive glycosylated nanoformulations for extended trans-corneal drug delivery to suppress corneal neovascularization.

Eye-drop formulations as conventional regimens to tackle ocular diseases are far from efficient due to the rapid clearance by eye tears and the blockage of the corneal epithelium barrier. Here, we describe a bioadhesive glycosylated nanoplatform with boric acid pendants as a drug carrier for noninvasive trans-corneal delivery of drugs to treat corneal neovascularization (CNV), a serious corneal disease resulting in significant vision impairment. This biocompatible nanoplatform is formulated from a synthetic amphiphilic boric acid-based copolymer self-assembling to form highly stable micelles with a high loading capacity for dexamethasone (DEX). The nanoplatform is demonstrated to be in contact with the corneal epithelium for a long period under the bioadhesive function of boric acid modules and releases the drug over 96 h in a controlled manner. Our results also suggest that the nanoplatform can be efficiently internalized by corneal epithelial cells in vitro and realize transcytosis in vivo to greatly enhance the transcorneal penetration of the loaded drugs into the pathological corneal stroma. On topical application against rat corneal alkali burn, the nanoformulation presents more robust efficacy on neovascularization suppression and inflammation elimination than free DEX with a negligible effect on normal tissues. This bioadhesive strategy which focuses on extending ocular drug retention and improving trans-corneal drug delivery not only highlights an approach for alternative noninvasive therapy of CNV but also provides a versatile paradigm for other biomedical applications by overcoming protective barriers.